GB2320062A

GB2320062A - Scroll compressor

Info

Publication number: GB2320062A
Application number: GB9802496A
Authority: GB
Inventors: Fumiaki Sano; Yoshihide Ogawa; Masayuki Kakuda; Kiyoharu Ikeda; Shuji Motegi; Toshiyuki Nakamura; Eiji Watanabe; Hitoshi Ogawa; Norihide Kobayashi
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 1994-07-22
Filing date: 1995-07-21
Publication date: 1998-06-10
Anticipated expiration: 2015-07-21
Also published as: GB9801300D0; GB2319064B; GB2319066B; GB9801856D0; GB9801855D0; GB2320062A8; GB2319064A; GB2319065A; GB2319066A; GB2320062B; GB2319065B; GB9802496D0

Abstract

An orbiting scroll 2 meshes with a non-orbital scroll 1 to form a compression space. A frame 3 axially supporting the orbiting scroll 2 and radially supporting a drive shaft 8, is coupled to the non-orbital scroll 1 through a plate spring 12. A high and low pressure separator 4 is fixed to the compressor vessel 9. The non-orbital scroll 1 can make axial movement within a limited range interferes with the orbiting scroll 2 downwards in the axial direction and with the high and low pressure separator 4 upwards in the axial direction.

Description

2320062 1 SCROLL CONTRESSOR

This specification has been divided from application number 9515030.6 and the reader's attention is directed to the corresponding publication GB 2 291 691 A.

This invention relates to a scroll compressor used in an air conditioner, a refrigerator, etc.

Figure 20 is a longitudinal sectional view of a scroll compressor disclosed in Japanese Patent Laid-Open No.Sho 62-199986 (conventional example 1).

In Fig. 20, numeral 1 is a fixed scroll having one lower side formed with a plate-like spiral tooth la, and a bed plate 1b has an outer periphery in the form of a cylindrical surface. A protrusion in the form of a hollow circular column is formed on the opposite face to the platelike spiral tooth la (upper side of the fixed scroll 1) and a groove for housing a seal member 10 separating high pressure and low pressure is formed on the outer face of the protrusion.

Numeral 2 is an orbiting scroll having one upper side formed with a platelike spiral tooth 2a, and a boss part 2b receiving a drive force from a spindle 8 is projected on the opposite side (lower side).

Numeral 3 is a frame having an outer peripheral surface stuck to a sealed vessel 9 and an upper end face fixed to a high and low pressure separator 4. The frame 3 supports a thrust load of the orbiting scroll 2 and supports the spindle 8 radially.

2 The fixed scroll 1 is restrained in radial and rotation directions by a pin 5 pressed into the high and low pressure separator 4.

Numeral 7 is an Oldhamls coupling for restraining rotation of the orbiting scroll 2 and determining a phase between the orbiting scroll 2 and the frame 3.

Numeral 8 is a spindle and torque for driving the orbiting scroll 2 is given from a motor thereto.

Numeral 4e is an oil return hole made in the high and low pressure separator 4, and an oil return hole 3f is also made in the frame 3 at a position corresponding to the oil return hole 4e.

Next, the operation of the scroll compressor in the conventional example 1 will be discussed. First, an. axial force that acts on the fixed scroll 1 will be described. An upward pushing force caused by gas pressure in the compression space acts on the fixed compressor 1. On the other hand, high pressure acts on the center of the seal member 10 on the rear of the fixed scroll 1 to cause a force which presses the fixed scroll 1 to slide along the pin 5 pressure-inserted into the high and low pressure separator as a guide downward against the orbiting scroll 2.

Next, a radial force that acts on the fixed scroll 1 will be described. A radial force mainly caused by gas pressure in the compression space acts on the plate-like spiral tooth la of the fixed scroll 1. The force is 3 transmitted via a boss part lg, projecting from the base plate lb of the fixed scroll 1, to the high and low pressure separator 4.

Next, a moment in the rotation direction that acts on the fixed scroll 1 will be described. A moment in the rotation direction mainly caused by gas pressure in the compression space acts on the fixed scroll 1 like the orbiting scroll 2. At the orbiting scroll 2, the moment is received by the Oldhamls coupling 7; at the fixed scroll 1, it is received by means of the pin 5.

A scroll compressor having a similar structure is disclosed in Japanese Patent Laid-Open No.Hei 5-263776 (conventional example 2), in which the outer periphery of the base plate lb of the fixed scroll 1 and the abutment.surface of the frame 3, that receives the outer periphery of the base plate 1b movably in the axial, upward direction, are both enlarged in diameter in the direction opposite from the compression space to form tapered surfaces, and a minute clearance is formed between the tip and bottom of the platelike spiral teeth. In the conventional example 2, a plurality of pins 5 are projected on the frame 3 to restrict the movement of the fixed scroll 1 in the circumferential direction.

Figure 21 is a longitudinal sectional view of a scroll compressor disclosed in Japanese Patent Laid-Open No.Sho 63-80088 (conventional example 3).

4- The structure and operation of conventional example 3 will be discussed with referenced to Figure 21. Parts identical with or similar to those previously described with reference to Figure 20 are denoted by the same reference numerals in Figure 21 and will not be discussed again. Numeral 1 is a fixed scroll and four screw holes for bolts are provided around the outer periphery of a base plate lb. Numeral 12 is a plate spring formed with four drill holes for bolts. Bolts are inserted into the two drill holes at both ends of the plate spring 12 for fixing the plate spring 12 to the upper end face of the elongated portion of the base plate 1b of the fixed scroll 1. Also, bolts 15 are inserted into the two drill holes at the center of the plate spring 12 for fixing the plate spring 12 to the upper end face of a frame 3. Thus, the fixed scroll 1 and the frame 3 are elastically coupled axially by the plate spring 12, but basically fixedly coupled in radial direction and rotation direction around the axis.

Means for restraining an axial upward movement of the fixed scroll 1 is a member stuck to the frame 3 by the bolts 15. A high and low pressure separator 4 is not positioned with respect to the frame 3 and is welded all around to a sealed vessel 9.

Figure 22 is a longitudinal sectional view of a scroll compressor disclosed in Japanese Patent Laid-Open No.Hei 4-231691 (conventional example 4).

In Figure 22, numeral 1 is a fixed scroll 1 having a planar.portion lq on the surface opposite from the spiral tooth of a base plate lb. Numeral 4 is a high and low pressure separator having a planar portion 4c parallel with the planar portion lq of the fixed scroll 1. Numeral 10 is a seal member for sealing high and low pressure, which is located between the planar portions.

The high and low pressure separator 4 is welded all around to a sealed vessel 9 at a junction 4d.

Figure 23 is a longitudinal sectional view of the main part showing a conventional scroll compressor, for example, disclosed in Japanese Patent Laid-Open No.Hei 5149269, wherein numeral 9 is a sealed vessel, and numeral 1 is a fixed scroll that has a base plate lb placed near to one end face 9a in the sealed vessel 9, a fixed scroll plate-like spiral tooth la formed on the side of the base plate 4 opposite from the end face 9a, a circular cylinder 35 provided at the center of the base plate lb and placed on the side of the end face 9a, a protrusion edge 36 protruding from the outer peripheral surface of the base plate lb toward the end face 9a, and a discharge port le arranged at the center of the base plate lb.

Numeral 2 is an orbiting scroll having an orbiting scroll plate-like spiral tooth 2a disposed on a base plate 2c facing the fixed scroll platelike spiral tooth la to engage the fixed scroll plate-like spiral tooth la for forming a compression space 21, and a boss 23 formed on the side of the base plate 2c opposite from the orbiting scroll plate-like spiral tooth 2a.

Numeral 3 is a frame which has an outer peripheral surface fixed in the sealed vessel 9 and is placed on the side of the orbiting scroll 2 opposite from the fixed scroll 1 and provided with a bolt 37 inserted in the fixed scroll 1 and screwed into the upper end for displacably holding the fixed scroll 1 in the central axial direction of the sealed vessel 9 and prohibiting displacement of the fixed scroll 1 toward the end face 9a at a predetermined position and diametric and pivotal displacement of the fixed scroll 1 with respect to the sealed vessel 9.

Numeral 4 is a high and low pressure separator fixed between the fixed scroll 1 and the end face 9a of the sealed vessel 9 and provided with a fit circular cylinder 38 fitted in the circular cylinder 6 at the opposite face to the fixed scroll 1, a fit protrusion 39 fitted in the protrusion edge 36 at the opposite face to the fixed scroll 1, and a discharge port 4f placed at the center.

Numeral 10 is a seal member provided between the circular cylinder 35 and the fit circular cylinder 38. Numeral 11 is a seal member provided between the protrusion edge 36 and the fit protrusion 39.

Numeral 22 is a high pressure chamber formed in the discharge port 4f of the high and low pressure separator 4, numeral 4a is a back pressure chamber defined by the circular cylinder 35, the protrusion edge 36, the fit circular cylinder 38, and the fit- protrusion 39, and numeral 24 is a low pressure chamber defined by the protrusion edge 36, the fit protrusion 39, and the side face of the sealed vessel 1 confronted thereto.

Numeral ld is an extraction hole made in the base plate 1b of the fixed scroll 1 and communicated with the compression space 21 and the back pressure chamber 4a. Numeral 26 is an Oldhamls coupling disposed between the base plate 2c of the orbiting scroll 2 and the frame 3 for restraining the rotation of the orbiting scroll 2 and positioning the orbiting scroll 2 and the frame 3.

Numeral 8 is a shaft of an electric motor (not shown) provided in the sealed vessel 9 and fitted in the boss 23 of the orbiting scroll 2 for driving the orbiting scroll 2.

The conventional scroll compressor is structured as mentioned above, and when the electric motor is energized, the shaft 8 turns and drives the orbiting scroll 2, whereby the volume of the compression space 21 defined by the fixed scroll plate-like spiral tooth la and the orbiting scroll plate-like spiral tooth 2a decreases from the outer periphery to inner periphery of the spiral teeth. A low-pressure refrigerant gas flows into the compression space 21 and-is compressed to a high-pressure refrigerant gas, which is sent from the discharge port le of the fixed scroll 1 to the discharge port 4f of the high and low pressure separator 14 provided eccentrically with the discharge port le.

At this time, a press force in a direction toward the end face 9a of the sealed vessel 9 is caused by refrigerant gas pressure in the compression space 21 and acts on the fixed scroll 1. On the other hand, a high pressure acts on the high and low pressure separator (4) side of the fixed scroll 1 and the inside of the seal member 10, and an intermediate pressure acts on the back pressure chamber 4a. The refrigerant gas pressure causes the fixed scroll 1 to be pressed against the orbiting scroll 2.

Figure 24 is a longitudinal sectional view of the main part showing another conventional scroll compressor, for example, disclosed in Japanese Patent Laid-Open No.Hei 526180. Parts identical with or similar to those previously described with reference to Figure 23 are denoted by the same reference numerals in Figure 24. Numeral 28 is a pressure release device made up of a relief port 29 and an opening/closing valve 30 disposed in a high and low pressure separator 4.

The conventional scroll compressor having the structure in Figure 24 also operates like the scroll compressor in Figure 23, to compress a refrigerant gas. When the pressure in a back pressure chamber 4a becomes higher than that in a high pressure chamber 22, the pressure release device 28, namely, the opening/closing valve 30 opens.

3 In the conventional scroll compressor, namely that described in Japanese Patent Laid-Open No.Sho 62-199986, since the pin 5 pressure-inserted into the base plate lb of the fixed scroll 1 supports the radial load of the fixed scroll 1, area of the sliding portion is restricted thereby, and abnormal wearing of the guide part occurs due to occurrence of the incomplete contact or the like by the tilt of the fixed scroll.

In the conventional scroll compressor of the example 2 as described in Japanese Patent Laid-Open No.Hei 5-263776, the axial support member for the fixed scroll 1 is the upper end face (a tapered surface enlarged in diameter in a direction opposite from the compression chamber) of the frame 3, and a clearance is formed between the tip and bottom of the plate-like spiral teeth, and thus the fixed scroll 1 does not come in axial contact with the orbiting scroll 2; resultantly, a gap occurs between the plate-like spiral tooth tip and bottom and leakage from the gap deteriorates efficiency. Further, the fixed scroll tilts along the tapered surface, as a consequence of which a gap occurs and leakage from the gap deteriorates the efficiency.

In the conventional scroll compressor, namely that disclosed in Japanese Patent Laid-Open No.Sho 63-80088 (the conventional example 3), there are provided a seal member 10 for separating a discharge space (high pressure) and an - intermediate pressure chamber 4a (intermediate pressure) and a seal member 11 for separating the intermediate pressure chamber,4a (intermediate pressure) and a suction space 24 (low pressure) on circular cylinder faces provided on the top of the fixed scroll 1. In this cased, there are a plurality of circular cylinder face fitting portions in assembling the fixed scroll 1 to the high and low pressure separator 4, which make it difficult to assemble them together, and in addition thereto, since clearance imbalance between the fitting portions is caused by a machining error, the seal failure occurs at seal places.

For example, if a valve (not-shown in the drawings) for a suction pipe of the compressor is failed to open at the initial operation of the scroll compressor, there occurs socalled vacuum operation in which suction pressure (low pressure) becomes close to vacuum. In the conventional scroll compressor of the example 3 as disclosed in Japanese Patent LaidOpen No.Sho 63-80088, the fixed scroll 1 is strongly pressed against the orbiting scroll 2 at the vacuum operation due to high pressure in the discharge space, thus the tooth tip is seized. At the vacuum operation, little refrigerant gas flows, and the plate-like spiral tooth la of the fixed scroll and the plate-like spiral tooth 2a of the orbiting scroll become high in temperature. Further, a minute amount of lubrication oil normally supplied together with refrigerant gas is not supplied either. 'Under this condition, if the tooth tip of the plate-like spiral tooth is 11 strongly pressed against the tooth bottom of the mate, the tooth tip is seized at high possibility.

In a scroll compressor, balanced compression operation can be achieved as the volumes of paired crescentshaped compression spaces decrease in synchronization. Since the scroll compressor similar to the conventional scroll compressor of the example 3 as disclosed in Japanese Patent LaidOpen No.Sho 63-80088 is formed with only one extraction hole ld, the compression space communicated with the intermediate pressure chamber 4a via the extraction hole and the other compression space becomes unbalanced because of the presence or absence of the effect of the intermediate pressure chamber 4a. Thus, an abnormal rotation moment occurs in the fixed scroll 1 and the orbiting scroll 2, causing trouble on reliability.

In the conventional scroll compressor of the example 3 as disclosed in Japanese Patent Laid-Open No.Sho 63-80088, the tooth tips of the platelike spiral teeth always come in slide contact with the tooth bottoms at the steady operation time, thus wear of the tooth tips is developed. As a result, the stroke volume of the compressor decreases and the compressor does not provide a predetermined capability or the refrigerant circuit throttle is clogged with wear powder, causing refrigeration failure.

In the conventional scroll compressor of example 3 as disclosed in Japanese Patent Laid-Open No.Sho 63-80088, the 12- plate spring 12 connecting the fixed scroll 1 and the frame 3 is fastened to the fixed scroll 1 and the frame 3 simply by bolts, thus shifts during the operation, particularly when receiving high pressure at the liquid compression time or the like; performance failure occurs due to out-ofphase or noise increases due to diametric shift.

In the conventional scroll compressor of the example 3 as disclosed in Japanese Patent Laid-Open No.Sho 63-80088, the plate spring 12 is fixed to the upper end face of the extension of the base plate 1b of the fixed scroll 1 by bolts. Thus, the screw holes for the bolt must be made in the base plate extension below it, and the fixed scroll 1 has a large volume more than necessary. As a result, the fixed scroll 1 is poor in follow-up operability; it is disadvantageous for performance and reliability.

The conventional scroll compressor of the example as disclosed in Japanese Patent Laid-Open No.Sho 63-80088 does not contain means for positioning the fixed scroll 1 and the frame 3 (the frame 3 being phase- determined with the orbiting scroll 2 by the Oldhamls coupling). Thus, the fixed scroll 1 and the orbiting scroll 2 shifts relative to each other, and a large leakage gap occurs in the crescent-shaped compression chambers defined by plate-like spiral teeth in the radial direction and efficiency extremely lowers due to a leakage loss.

In the conventional scroll compressor of the example 3 G 4 as disclosed in Japanese Patent Laid-Open No.Hei 4-231691, the high and low pressure separator 4 is welded to the sealed vessel 9 at a distance from an axial position of the seal face lq parallel with the base plate of-the fixed scroll 1. Since a diametric shrinkage force acts on the weld, the high and low pressure separator after the welding receives a bend moment caused by the shrinkage force and attempts to be deformed. Since the axial positions of the weld and the seal face position of the high and low pressure separator are distant in the conventional scroll compressor, the welding load acting distance on the seal face is long. Thus, the bend moment increases, the seal face is deformed, and the seal characteristic worsens.

In the conventional scroll compressor of the example 3 as disclosed in Japanese Patent Laid-Open No.Sho 63-80088, the upward travel distance of the fixed scroll 1 (in a direction distant from the orbiting scroll 2) is regulated by means of bolts 37 fastened to the frame 3 (strictly, a member sandwiched between the bolts and the frame 3). Thus, when the fixed scroll 1 performs upward relief operation with large acceleration at the liquid compression operation, etc., the fastening force of the bolts 15 fixing the spring plate 12 to the frame 3 is impaired.

Since the scroll compressor similar to the conventional scroll compressor of the example 3 as disclosed in Japanese Patent Laid-Open No.Sho 6380088 is formed with 4 the intermediate pressure chamber 4a before it is started, for example, when it is started with full liquid wherein the compression chamber is filled with liquid refrigerant, oil or the like, the intermediate pressure chamber 4a becomes intermediate pressure just after the starting, and the fixed scroll 1 is strongly pressed against the orbiting scroll 2. At the time, the tooth tips of the plate-like spiral teeth la and 2a of the fixed and orbiting scroll 1 and 2 are seized.

In the conventional scroll compressor of the example 3 as disclosed in Japanese Patent Laid-Open No.Sho 63-80088, the plate spring 12 is made of sheets and is low in axial rigidity and can be displaced by a weak force, but is high in radial rigidity and hard to be displaced in an assembly condition.

when a liquid refrigerant flows into the compression space and is compressed and pressure in the compression space abnormally rises, such a characteristic is advantageous for the fixed scroll 1 to axially move for relieving the pressure in the compression space. As the compressor volume increases, the thickness of the sheet members needs to be increased to provide the strength of the plate spring. However, the axial rigidity is proportional to the cube of the thickness and therefore becomes too strong and the axial relief characteristic worsens.

The scroll compressor similar to the conventional scroll compressor of the example 3 as disclosed in Japanese Patent Laid-Open No.Sho 63-80088 has axial dimensions set so that the spiral tooth tip of the fixed scroll and the spiral tooth bottom of the orbiting scroll and the spiral tooth tip of the orbiting scroll and the spiral tooth bottom of the fixed scroll come in contact with each other almost at the same time. For light weight to decrease vibration, the orbiting scroll often uses a light alloy such as an aluminum alloy. Since the light alloy is soft for iron-family material, wear is prone to develop and wear of the spiral tooth tips increases.

In the conventional scroll compressor of the example 1 as disclosed in Japanese Patent Laid-Open No.Sho 63-80088, the high and low pressure separator 4 is formed with an oil return hole 4e and the frame 3 is also formed with an oil return hole 3f at a position corresponding to the oil return hole 4e. Thus, when the compressor is assembled, the high and low pressure separator 4 and the frame 3 need to be diametrically positioned. In addition, when the high and low pressure separator has a diametrically asymmetric form, diametric positioning is also required. Thus, when the compressor is assembled, alignment is required with jigs and tools and defective positioning or the like also occurs.

In the conventional scroll compressor shown in Figure 23, the central axial line of the discharge port le of the fixed scroll 1 is eccentric with that of the discharge port 4f of the high and low pressure separator 4. Thus, when the 16 refrigerant gas is discharged, a pressure loss, etc., caused by a complicated flow passage form of the dis=harge ports le and 4f provided eccentrically with each other increases, lowering the compression efficiency.

in the conventional scroll compressor shown in Figure 24, the central axial line of the relief port 29 of the high and low pressure separator 4 is eccentric with that of an extraction hole 1d of a fixed scroll 1. Thus, for example, if the pressure in a compression space 21 abnormally rises, the pressure in the back pressure chamber 4a communicated with the compression chamber 21 through the extraction hole id also abnormally rises. However, the operation of the pressure release device 28 when the pressure in the back pressure chamber 4a abnormally rises is delayed because the relief port 29 and the extraction hole 1d are provided eccentrically with each other; pressure release is delayed.

Therefore, the high pressure condition in the back pressure chamber 4a continues for a while, and a force pressing the fixed scroll 1, namely, a press force acting on the orbiting scroll 2 becomes excessive, promoting tooth tip wear of the fixed scroll plate-like spiral tooth la and the orbiting scroll plate-like spiral tooth 2a or damaging them.

It mould accordingly be desirable to be able to provide a scroll compressor which does not 17 create gaps between plate-like spiral teeth and between a tooth tip and a tooth bottom of plate-like spiral teeth and in which guide and pin parts are free from abnormal wear or the like, to thereby achieve high efficiency and high reliability compatible with each other.

It would also be desirable to provide a scroll compressor which is improved in assembly and prevents seal failure from occurring at the seal places.

It would also be desirable to to provide a highly reliable scroll compressor which prevents the tooth tip of the plate-like spiral tooth from being seized even at the vacuum operation time.

It would also be desirable to provide a scroll compressor which prevents the paired compression spaces from becoming unbalanced.

It would also be desirable to provide a scroll compressor which ensures a stable capability without periodical change of the plate-like spiral tooth and prevents the refrigerant circuit throttle from being clogged with wear particles.

It would also be desirable to provide a high performance, low-noise scroll compressor wherein the plate spring does not shift, namely, the fixed scroll does not shift even in an operation condition in which an excessive load acts on the spiral at the liquid compression time, etc.

It would also be desirable to provide a high- is 1 performance and high-reliability scroll compressor which can make the fixed scroll small in volume, and is good in axial minute follow-up operability of the fixed scroll during the operation.

It would also be desirable to provide a scroll compressor wherein phase between the fixed scroll and the orbiting scroll is accurately adjusted to ensure high efficiency at the steady operation time.

It would also be desirable to provide a scroll compressor which has a good seal characteristic by decreasing deformation of the seal face when the high and low pressure separator is welded to the sealed vessel.

It would also be desirable to provide a high- reliability scroll compressor which is free from damage of parts and fastening failure of parts even when the fixed scroll is upward relieved with large acceleration at the liquid compression operation, etc.

It would also be desirable to provide a high- reliability scroll compressor wherein the tooth tips are not seized when it is started will full liquid wherein the compression chamber is filled with liquid refrigerant, oil or the like.

It wmld also be desirable to provide a scroll compressor which maintains a good axial relief characteristi even if the compressor volume increases and the plate spring strength is enhanced.

113 It would also be desirable to reduce wear of the orbiting scroll plate-like spiral tooth tips while being lighten in weight.

It would also be desirable to simply perform positioning of the high and low pressure separator and the frame without use of special assembly jigs, etc.

It would also be desirable to provide a scroll compressor which is good in operation efficiency with less compression loss when a refrigerant gas is discharged.

It would also be desirable to provide a scroll compressor with high operation reliability wherein when pressure in a compression space abnormally rises, pressure in a back pressure chamber is released without delay for preventing a failure from occurring.

Document #: 224301 The present invention provides a scroll compressor comprising in a sealed vessel:

a fixed (non-orbital) scroll formed with a plate-like spiral tooth on one side of a base plate of the fixed scroll; an orbiting scroll formed with a plate-like spiral tooth of substantially the same form as the plate-like spiral tooth of the fixed scroll on one side of a base plate of the orbiting scroll and a shaft or a bearing for receiving a driving force on an opposite side of the base plate, the orbiting scroll executing orbiting motion with respect to the fixed scroll; a frame fixedly supported to the sealed vessel for axially supporting the orbiting scroll and radially supporting a drive shaft, the frame being coupled to the fixed scroll through a plate spring; and a high and low pressure separator located at an opposite side of the fixed scroll with respect to the orbiting scroll and fixed to the sealed vessel, wherein:

an axial (upward) travel distance of a side of the fixed scroll opposite from a plate-like spiral tooth side is regulated by interference with the high and low pressure separator or a member attached to the high and low pressure separator.

Thus, a strong upward collision of the non-orbital scroll occurring at the liquid compression time, etc., is received by the high and low pressure separator, and damage to the other parts or fastening failure is not caused by collision.

21 Preferably, when the high and low pressure separator is to be fixed to the sealed vessel, it is axially positioned by pressing it against the frame or a member attached to the frame. Thus, the distance between the high and low pressure separator and the non-orbital scroll can be easily managed with high accuracy, providing a high-reliability scroll compressor wherein the parallelism of the high and low pressure separator and the non-orbital scroll can be well managed and a single hit when the non-orbital scroll is managed accurately, trouble such that the maximum relief amount is too excessive to provide a compression function at starting does not occur. Preferred and optional features of the invention are set forth in the

subsidiary claims.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

Figure 1 is a longitudinal sectional view of a scroll compressor not in accordance with the invention; Figure 2 is an enlarged view of the main part of the scroll compressor; Figures 3A and 3B are perspective views for illustrating a seal member and a backup member of the scroll compressor, respectively; Figure 3C, 3D and 4 are sectional views for illustrating states of the seal member and the backup member mounted in place; Figure 5 is a sectional view of the main part of a modification of the scroll compressor; 1 22 Figure 6 is a sectional view of the main part of another modification of the -Scroll compressor; Figure 7 is a sectional view of the main part of another modification of the scroll compressor; Figure 8A is a sectional view for illustrating another modification of the scroll compressor and Figure 8 is a sectional view taken along line 8B8B of Figure 8A; Figure 9 is a longitudinal sectional view of a scroll compressor according to a first embodiment of the invention; Figure 10 is a perspective view of the main part of a scroll compressor according to the first embodiment of the invention; Figure 11 is a longitudinal sectional view of the main part of scroll compressors according to a second embodiment of the invention; Figure 12 is a perspective view of the main part of a scroll compressor according to the second embodiment of the invention; Figures 13A and 13B are sectional views of the main part of a scroll compressor according to a third embodiment of the invention; Figure 14 is a perspective view of the main part of a scroll compressor according to a fourth embodiment of the invention; 23 Figure 15 is a sectional view of the main part of a scroll compressor according to a fifth embodiment of the invention; Figure 16 is a sectional view of the main part of a scroll compressor according to a sixth embodiment of the invention; Figure 17 is a perspective view of the main part of a scroll compressor according to a seventh embodiment of the invention; Figure 18 is a longitudinal sectional view of a scroll compressor according to an eighth embodiment of the invention; Figure 19 is a longitudinal sectional view of a scroll compressor according to a ninth embodiment of the invention; Figure 20 is a longitudinal sectional view of a conventional scroll compressor; Figure 21 is a longitudinal sectional view of another conventional scroll compressor; Figure 22 is a longitudinal sectional view of another conventional scroll compressor; Figure 23 is a longitudinal sectional view of another conventional scroll compressor; 24 Figure 24 is a longitudinal sectional view of another conventional scroll compressor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the accompanying dxawings, there are shown preferred embodiments of the invention. Parts identical with or similar to those described in the conventional examples and embodiments are denoted by the same reference numerals and will not be discussed again.

Figure 1 is a longitudinal sectional view of a scroll compressor which is not an embodiment of the invention. A non-orbital scroll referred to as a fixed scroll 1 has, on its lower side, a plate-like spiral tooth l a and has a base plate 1b with an outer peripheral portion lc formed like a cylinder. Grooves for housing an inner seal member 10 for separating high pressure and intermediate pressure and an outer seal member 11 for separating intermediate pressure and low pressure are formed on the opposite face from the plate-like spiral tooth la (upper side of the fixed scroll 1). Further, an extraction hole ld is formed in the base plate 1b of the fixed scroll 1 for guiding gas being compressed (intermediate pressure) to an intermediate pressure chamber 4a defined by the fixed scroll base plate lb, a high and low pressure separator 4, and the two seal members 10 and 11.

An orbital or orbiting scroll 2 has a base plate 2c whose upper side is provided with a plate-like spiral tooth 2a, and a boss part 2b receiving a drive force from a 2G spindle 8 is projected on the opposite side (lower side).

Numeral 3 is a frame having an outer peripheral surface stuck to a sealed vessel 9 with high-pressure space above the stuck place and low-pressure space below it. The upper end face of the frame 3 is fastened to the high and low pressure separator 4 (constituting a stationary member) by a bolt. The frame supports a thrust load of the orbiting scroll 2 and supports the spindle 8 radially.

The frame 3 and the high and low pressure separator 4 are positioned in radial and rotation directions by a positioning pin 6 such as a reamer pin, and the fixed scroll 1 is restrained in the rotation directions by a rotation regulation pin or key 5 such as a reamer pin pressed into the high and low pressure separator 4 and constituting a. rotational direction regulation means.

The high and low pressure separator 4 is formed with a recess formed like a circular cylinder at the lower part. The fixed scroll base plate is fitted in the recess and a radial load acting on the fixed scroll 1 is transmitted via the fit part to the high and low pressure separator.

Numeral 8 is a spindle and torque for driving the orbiting scroll 2 is given from a motor. Numeral 21 is a compression space formed by the platelike spiral teeth la - X - 27 and 2a by combining the fixed scroll 1 and the orbiting scroll 2. In addition, a plurality of compression spaces, although omitted in Fig. 1, are defined by the plate-like spiral teeth la and 1b similarly to a commonly known scroll compression as explained along the conventional art above.

In Figure 2, fit clearance 6b of the rotation regulation pin 5 is set larger than fit clearance Sa of the fixed scroll base plate outer peripheral surface lc. The axial position of the fit of the rotation regulation pin 5 substantially matches that of the fixed scroll outer peripheral surface lc.

Numeral 17 is a suction pipe communicated with a suction port of the compression space via the low-pressure space of the lower half of the sealed vessel separated by the frame 3. Numeral 18 is a discharge pipe communicated with a discharge port le of the fixed scroll via the highpressure space of the upper half of the sealed vessel separated by the frame 3.

In Figures 3A to 3D, first a backup member 10a, an elastic member having a triangular cross section, is placed in the groove formed on the upper end face of the fixed scroll 1, then the inner seal member 10, a pressure seal member having a hexagonal cross section, is placed on the backup member 10a. The joint in the inner seal member is cut as a square cross section and hexagonal cross section, and the seal leakage does not occur owing to the provision of - m - 22 joint shown in Fig. 3A. The inner seal member 10, as best shown in Figure 4, is chamfered at the upper corner of the outer peripheral surface, and the axial chamfer dimension 6d is set larger than the maximum relief amount of the fixed scroll 1, 6c. The description on the inner seal member 10 and the backup member 10a is also applied to the outer seal member 11 and a backup member lla.

Next, the operation of the scroll compressor of the first embodiment will be discussed. Figure 1 shows a state of the scroll compressor during the steady operation.

First, an axial force that acts on the fixed scroll 1 will be described. An upward pushing force caused by gas pressure in the compression space acts on the fixed compressor 1. On the other hand, on the rear of the. fixed scroll 1, high pressure acts on the center of the inner seal member 10 and intermediate pressure acts on the part exposed to the intermediate pressure chamber 4a between the inner seal member 10 and the outer seal member 11; totally, the fixed scroll 1 is pressed lightly downward, namely, against the orbiting scroll 2.

Next, a radial force that acts on the fixed compressor 1 will be described. A radial force mainly caused by gas pressure in the compression space acts on the platelike spiral tooth la of the fixed scroll 1. As a rule, the force is transmitted via the fixed scroll base plate outer peripheral surface lc rather than the rotation regulation pin - X - 25> to the high and low pressure separator 4, because the clearance 6b of the rotation regulation pin 5 is set larger than the fit clearance Sa of the base plate outer peripheral surface lc as described above.

Next, a moment in the rotation direction that acts on the fixed scroll 1 will be described. A moment in the rotation direction mainly caused by gas pressure in the compression space acts on the fixed scroll 1 like the orbiting scroll 2. At the orbiting scroll 2, the moment is received by the Oldham's coupling 7; at the fixed scroll 1, it is received by means of the rotation regulation pin 5. The fixed scroll base plate outer peripheral surface lc, which is a cylindrical fitting, cannot receive the moment as a rule, needless to say.

The phase between the orbiting scroll 2 and the frame 3 of the scroll compressor 1 of the first embodiment is determined by the Oldhamls coupling, the phase between the frame 3 and the high and low pressure separator 4 is determined by the positioning pin 6, and the phase between the high and low pressure separator 4 and the fixed scroll 1 is determined by the rotation regulation pin 5. Consequently, the phase between the fixed scroll 1 and the orbiting scroll 2 is securely determined although indirectly.

In Figure 1, the base plate outer peripheral surface lc of the fixed scroll 1 is supported radially by the high and low pressure separator 4 constituting a stationary member - In - and formed like a circular cylinder coaxial with the base plate outer peripheral surface lc, and with it as a guide, the fixed scroll 1 can make axial movement within the range in which it interferes with the orbiting. scroll 2 downward in the axial direction and with the high and low pressure separator 4 upward in the axial direction. Like the high and low pressure separator, the fixed scroll 1 may be supported radially by the frame 3 for guiding axial vertical movement by fitting slidably the base plate outer peripheral surface lc of the fixed scroll 1 into the frame 3 as a stationary member.

In this embodiment, axial compliance means for enabling minute axial motion of the fixed scroll 1 is made up of the gas pressure in the compression chamber 21, which depresses the fixed scroll 1 axially upwardly, the gas pressure behind the fixed scroll 1, which depresses axially downwardly, the circular cylindrical portion of the stationary member 4, which supports the base plate outer peripheral surface lc of the fixed scroll 1 and guides the vertical motion thereof, and the orbiting scroll.

Next, the operation of the seal members will be discussed by taking the seal member 10 as an example. The same is applied to the outer seal member 11. Figures 3C and 3D show conditions at stop, and at relief after start, respectively. Since the backup member 10a, an elastic member, attempts to widen to the outer peripheral surface - 3C - 31 (i.e. radially outwardly) by its own elasticity at stop, the inner seal member 10 is picked up and lightly pressed against the high and low pressure separator 4. If the compressor is started in this condition, intermediate-pressure and high pressure are sealed just after the start. High pressure travels into the rear of the inner seal member 10, and the inner seal member 10 is more securely pressed against the high and low pressure separator 4. In this case, a condition in which the inner seal member 10 sinks and does not float up at the start does not occur. The condition described with reference to Figure 3C is also entered at the steady operation time.

At the relief operation, as the pressure in the compression space becomes abnormally large and the fixed scroll 1 approaches the high and low pressure separator 4, the inner seal member 10 sinks. At the time, the inner seal member 10 drops in the groove relatively downward as the form remains unchanged, but the backup member 10a shrinks, namely, its diameter lessens by the force of the inner seal member 10.

The upper corner on the outer peripheral surface of the seal member 10 minutely deforms in the outer peripheral direction due to the pressure difference, but is chamfered. Thus, it is not sandwiched between the fixed scroll 1 and high and low pressure separator 4 at the relief operation.

Although the ring spring having a triangular cross 512 71 section is used as the elastic member in the first embodiment, a similar effect is also produced with a wave spring, etc.

The configurations of the seal member 10 and the backup member 10a are not restricted to those shown in Figs. 3A to 3D, and 4. The backup member 10a may have any configuration as long as it is in the form of a ring and has an upper slope surface which is gradually smaller in height from the ring inner periphery to the outer periphery, a surface which receive the pressure of the high pressure side within a groove accommodating the seal member, and a surface which contacts the bottom of the groove and is movable on that bottom. As to the seal member 10, it may have any configuration as long as it is in the form of a ring.and has a surface which is to be mounted onto the upper slope surface of the backup member 10a and surfaces which are brought into tight contact with a lower surface of the high and low pressure separator and a surface of low pressure side of the groove, respectively, when it is depressed toward the ring outer periphery through the slope surface by the backup member 10a.

3) In Figure 5, a groove for housing an inner seal member 10 located on the upper end face of a base plate lb of a fixed scroll 1 is formed integrally with a discharge port le of the fixed scroll 1. Therefore, the inner seal member 10 has almost the same inner diameter as the diameter of the discharge port le.

If a valve of a suction pipe 17 is failed to open or the like at initial start operation, so-called vacuum operation in which low pressure (suction pressure) becomes close to vacuum occurs. At the time, intermediate pressure is also made a considerably small value by the effect of the low pressure close to vacuum, thus a force that acts on the fixed scroll 1 is determined almost by the area (around the center) on which high pressure on the rear of the fixed scroll base plate 1b acts. In the scroll compressor of the second embodiment, the diameter of the inner seal member 10 is set small, so that the force pressing the fixed scroll 1 against an orbiting scroll 2 is small, and the axial relief state may be entered before vacuum is reached in some cases; vacuum is not reached. Therefore, at the vacuum operation, the fixed scroll 1 is not strongly pressed against the orbiting scroll 2.

In addition, the similar function and effect can also be obtained if the construction of the groove of the fixed scroll for housing the inner seal member 10 and the - X - 3L-- construction of the discharge portion le in this embodiment are applied to a scroll compressor having a leaf spring explained latter with reference to Fig. 9.

In Figure 6, two extraction holes id communicating a pair of compression spaces and an intermediate pressure chamber 4a with each other are made in a base plate 1b of a fixed scroll 1. The two extraction holes 1d are located at the same position for the paired compression spaces.

The scroll compressor performs the compression operation by decreasing the volume of the paired crescentshaped compression spaces. Since two extraction holes exist, the paired compression spaces are communicated via the intermediate pressure chamber 4a, so that unbalancing the two compression spaces is avoided.

In addition, the same function and effect can also be obtained if the construction wherein the extraction holes 1d are respectively formed for the paired compression spaces is applied to a scroll compressor having a leaf spring explained latter with reference to Figs. 8A and 8B.

515 In Figure 7, when the distance between the tip of a plate-like spiral tooth la of a fixed scroll 1, namely, tooth tip and the upper end face of a base plate 2c of an orbiting scroll 2, namely, tooth bottom, Se, is zero, the distance between the tip of a plate-'like spiral tooth 2a of the orbiting scroll 2, namely, tooth tip and the upper end face of a frame 3, 8f, is controlled between 5 gm and several ten gm. The outer form of a base plate 1b of the fixed scroll 1 is set larger than the inner diameter of the frame 3.

Thus, even if the tooth tip wears due to slide, the wearing does not develop endlessly. After it wears to some extent, the tooth bottom of the fixed scroll 1 and the upper end face 3a of the frame 3 (second interference member) are pressed against each other. As a result, a substantial gap does not exist and a force does not act either between the tooth tip of the fixed scroll 1 and the tooth bottom of the orbiting scroll 2 or the tooth bottom of the fixed scroll 1 and the tooth tip of the orbiting scroll 2. That is, after the scroll compressor is used for a long term, the stroke volume of the compressor does not reduce or a large amount of wear powder is not produced.

-5c the same as that shown in Fig. 1. In Figures 8A and 8B, a base plate outer peripheral surface lc of a fixed scroll 1 has a positional relationship lc' overlapping with a frame outer peripheral wall upper end face 3a with a plate spring 12 therebetween; their dimensional relationships are set so that a minute gap 8 exists axially when the fixed scroll 1 is in contact with an orbiting scroll 2.

When the distance between the fixed scroll 1 and the orbiting scroll 2 becomes close due to wear of tooth tips 2e and 1n of spiral teeth after the operation for a long time, fixed scroll base plate 1b comes in contact with the frame wall upper end face 3a with the plate spring whereby the pressing force of the fixed a part on the frame outer peripheral wall upper end face 3a and the pressing force of the tooth tips 2e and 1n of the spiral teeth decreases, stopping wear development of the tooth tips.

outer peripheral 12 therebetween, scroll 1 shares 37 Embodimentl:

The structure and operation of the first embodiment will be discussed with reference to Figures 9 and 10. Parts identical with or similar to those previously described with reference to Figures 1 to 4 are denoted by the same reference numerals in Figures 9 and 10 and will not be discussed again. Numeral 1 is a fixed scroll and four reamer bolt screw holes lg and two reamer holes 1h are formed around the outer peripheral surface of a base plate lb. Numeral 12 is plate or leaf springs each formed with four reamer holes. Reamer bolts 14 are inserted into the two reamer holes at both ends of the plate spring 12 for fixing it to the end face on the outer peripheral spiral side of the fixed scroll 1. Reamer bolts 15 are inserted into the two reamer holes at the center of the plate spring 12 for fixing it to an upper end face 3a of a frame 3.

The reamer bolt (reamer pin) is one machined having high accuracy in diametrical dimension (about 1Ogm allowable tolerance), so that it is possible to establish dimensional relationship required to assemble the components even if clearance of hole dimension on the plate spring side is set small. In this case, even if a shift or displacement occurs between the plate spring and the fixed scroll or the frame, the reamer bolt and the mating plate spring hole interfere to each other within a minute displacement (within the clearance) to prevent the further displacement beyond the 318 minute displacement. Thus, the displacement can be restricted to a small, minute amount, and such displacement can not adversely affect operation of the compressor substantively.

Since the fixed scroll 1 is completely restrained physically with respect to translational motion with the plate spring 12 by the reamer bolts 14, even if an excessive load acts on the fixed scroll 1 because of liquid compression, etc., the fixed scroll 1 and the spring plate 12 do not shift in a translational direction within a plane. Likewise, since the plate spring 12 is completely restrained physically with respect to translational motion with frame 3 by the reamer bolts 15, even if an excessive load is transmitted from the fixed scroll 1 to the plate spring 12 because of liquid compression, etc., the spring plate 12 and the frame 3 do not shift in a translational direction within a plane. In addition, two reamer bolts fixing the plate spring 12 to the fixed scroll 1 and two reamer bolts fixing the plate spring 12 to the frame 3 are provided, thus a rotation moment around the axis does not cause them to shift in the rotation direction. Although the fixed scroll 1 and the frame 3 are elastically coupled axially by the plate spring 12, but physically fixed in radial direction and rotation direction around the axis and do not shift during the operation.

Since the plate spring 12 is engaged in the end face 3K - 39 of the spiral side of the fixed scroll 1, the female screw parts of the reamer bolts 14 used for the engagement can be formed around the outer peripheral surface of the base plate 1b of the fixed scroll 1, so that the total weight of the fixed scroll 1 can be lessened. As a result, axial minute follow-up operability of the fixed scroll 1 is improved.

The plate spring and the fixed scroll or the plate spring and the frame are fastened by the reamer bolts, but may be fastened by reamer pins and bolts.

At assembly, namely, when the fixed scroll and the spring plate which are fastened by the bolts are fastened to the frame by the reamer bolts, reamer pins 13 are inserted into a reamer hole 1h of the fixed scroll 1 and a reamer hole 3c of the frame 3, whereby the fixed scroll 1, the frame 3, and orbiting scroll 2 are assembled in a condition in which phase is determined accurately. The reamer pins 13 are removed after completion of the assembly.

In this embodiment, compliance means for enabling minute axial motion of the fixed scroll 1 include the plate spring 12 coupling the fixed scroll 1 to the frame 3 in place of the cylindrical portion of the stationary member 4 supporting the base plate outer periphery lc and guiding vertical motion thereof in the Fi 9 tire l-' Embodiment 2:

Figures 11 and 12 are a longitudinal sectional view of a scroll compressor according to a second embodiment of - fK - the invention and a perspective view of the main part thereof. In Figures 11 and 12, numeral 1 is a fixed scroll and numeral ld is an extraction hole for guiding intermediate pressure to an intermediate pressure chamber 4a which is formed by separating a space between a fixed scroll base plate lb and a high and low pressure separator 4 by an inner seal member 10 and an outer seal member 11. An axial load that acts on the fixed scroll 1 to be pressed against an orbiting scroll 2 by a small force is produced by adjusting a force pressing the fixed scroll 1 against the high and low pressure separator 4 produced by the compression operation and a force releasing the fixed scroll 1 from the high and low pressure separator 4 that acts on the inner peripheral space of the inner seal member 10 and the intermediate pressure chamber 4a. With bolts 14 inserted into screw holes lg of the fixed scroll 1, the plate spring 12 is fastened to the spiral side face of the fixed scroll base plate lb. Further, with bolts 15 inserted into bolt holes 3b of the frame 3, the plate spring 12 is fastened to a frame outer peripheral wall upper end face 3a of the frame 3 from the top. The frame 3 and the fixed scroll 1 are positioned by inserting reamer pins 13 as jigs into reamer holes 3c and 1h. After they are fastened by the bolts 15, the reamer pins 13 are removed.

The frame 3 is formed with relief parts 3d for avoiding interference of the heads of the bolts 15. Each of - Mk - 41 the relief parts 3d is formed like a minimum necessary notch, spot facing, or equivalent recess to maximize the function of the frame outer peripheral wall as a strength member. The base plate outer peripheral surface of the fixed scroll 1 also has a relief part 1k for avoiding interference of the heads of the bolts 15. An attachment face 3g of the plate spring 12 is slightly higher than the frame end face 3a for allowing downward deformation of the spring.

The plate spring fastening part of the fixed scroll 1 has the structure as described abovef whereby the weight of the base plate can be reduced, lessening the total weight of the fixed scroll 1. As a result, axial minute follow-up operability of the fixed scroll 1 can be improved.

In Figure 11, numeral le is a discharge port.of the fixed scroll 1, numeral 17 is a suction pipe, and numeral 18 is a discharge pipe.

In addition, relief parts 1k and 3d similar to those of the second embodiment are formed in the first embodiment as shown in Figures 9 and 10.

The high and low pressure separator 4 is welded to the sealed vessel 9 near an axial position of a seal face lq parallel withthpbase plate oftKe. fixed scroll 1. Thus, a bend moment at welding that acts on a seal face of the high and 42- low pressure separator 4 is reduced and deformation of the seal face can be decreased.

Although the fixing for the high and low pressure separator 4 is performed by the tightening of a bolt to the upper end f ace of the f rame in Figure 1, the same effect as that of this embodiment can be obtained if the fixing may be performed in the same manner as that of this embodiment. Embodiment 3:

Figure 13A and 13B are sectional views for illustrating a scroll compressor according to a third embodiment of the invention, and particularly shows, in section, main portions of a scroll compressor under reliqEf and stop states (Fig. 13A), andsteady state (Fig. 13B) of plate spring. The entire construction of the scroll compressor is the same as that shown in Fig. 9 or 11. In Figures 13A, when a fixed scroll 1 is at the upper position, namely, when the fixed scroll 1 is completely relieved axially, the face on which a plate spring 12 engages the fixed scroll 1 is positioned below the face on which the plate spring 12 engages a frame 3. This distance is 6g shown in Figure 13A. Thus, the fixed scroll 1 closely contacts a high and low pressure separator 4 when it stops, namely, no gas load acts. Deflection amount of the plate spring 12 at steady operation, Sh, is the sum of maximum relief amount Sc and initial deflection amount Sg.

- 3w 43 In this embodiment, means for restraining an axial upward move of the fixed scroll 1 is the high and low pressure separator 4 constituting the stationary member. Even if the fixed scroll 1 is relieved upward with large acceleration due to liquid compression, etc., and collides with the high and low pressure separator 4, the high and low pressure separator 4 is strongly fixed to a sealed vessel 9 by welding all around, etc., so that trouble such that the high and low pressure separator 4 is detached does not occur.

In the stop state, the fixed scroll 1 closely contacts the high and low pressure separator 4. As a result, an intermediate pressure chamber 4a formed by the fixed scroll 1 and the high and low pressure separator 4 does not exist (the volume is zero). Thus, at start at which.liquid compression occurs containing start with full liquid, generation of a force downward pressing the fixed scroll 1 caused by pressure rise in the intermediate pressure chamber 4a is delayed and the compressor is smoothly started, preventing trouble such as start failure or compression element damage from occurring.

In Figure 11, the high and low pressure separator 4 is welded all around to the sealed vessel 9 with the separator 4 pressed against the upper end face of the frame 3. Thus, the maximum relief amount of the fixed scroll 1, Sc, can be managed only by managing the dimensions of the frame 3, anorbiting scroll 2, and the fixed scroll 1.

Therefore, the maximum relief amount Sc can be managed comparatively highly accurately; trouble such that at relief collision, parts are damaged or that the relief amount is too large to start (compress) does not occur. Embodiment +:

Figure 14 is a sectional view showing a scroll compressor the entire construction of which is the same as that shown in Fig - 9 or 11. In Figure 14, numeral 1 is a fixed scroll, numeral 3 is a frame, and numeral 12 is plate springs. The plate spring 12 is fastened in fixed scroll screw holes 1g by bolts 14 from the bottom. Further, the plate spring 12 is fastened to a frame outer peripheral wall upper end face 3a via bolt holes 3b by bolts 15 from the top. The plate spring 12 comprises a plurality of sheet springs 12 laminated on each other; it has sufficient diametric rigidity and can suppress axial rigidity. Generally, the axial rigidity becomes n 3 times when the thickness becomes n times, whereas it becomes substantially n times when n number of sheets are stacked one on another to provide the n-time thickness as a whole. Note that the diametric rigidity becomes n times in either of the cases. Embodiment 5:

Figure 15 is a sectional view showing main portions of a scroll compressor the entire construction of which is the same as that shown in Fig. 9 or 11. In Figure 15, a plate spring attachment face 11 of a fixed scroll 1 is formed - N1 - -45 with an inner peripheral side step part 1m for regulating displacement of a plate spring 12 to the inner peripheral side.

Further, a sealed shell inner wall face 9a is provided for regulating displacement of the plate spring 12 to the outer peripheral side.

Thus, displacement of the spring plate 12 to the inner and outer peripheral sides is regulated and diametric displacement of the spring plate 12 within a setup range is only allowed, whereby even if the plate spring 12 shifts from the fixed scroll 1 or the frame attachment face, the shift amount is regulated, preventing performance from lowering or noise from increasing. Embodiment 6:

Figure 16 is a sectional view showing main portions of a scroll compressor, and particularly shows a state of spiral tooth la of a fixed scroll and a spiral tooth 2a of an orbiting scroll of the scroll compressor. The entire construction of the scroll compressor shown in Fig. 16 is the same as that shown in Fig. 9. Figure 16 shows a contact state of plate-like spiral teeth la and 2a during the operation, wherein numeral 1 is a fixed scroll 1 and numeral 2 is an orbiting scroll.

The operation is performed while a spiral tooth tip 1n of the fixed scroll 1 comes in contact with a spiral tooth bottom 2d of the orbiting scroll 2. On the other hand, a 11 -4J, 1 - minute gap 82 exists between a spiral tooth tip 2e of the orbiting scroll 2 and a spiral tooth bottom lf of the fixed scroll 1. Such dimensional relationships among them enable delaying wear development of orbiting spiral. Particularly, the orbiting scroll can be made of a light alloy material to thereby make it light in weight and to achieve reduction of vibration.

In addition, the construction of this embodiment can be effectively applied to a type wherein a fixed scroll is fixedly provided as well as a type wherein a fixed scroll is capable of performing minute motion in the axial direction. Embodiment -7:

Figure 17 is a sectional view showing main portions of a scroll compressor the entire construction of which is the same as that shown in Fig. 9 cr 11. In Figure 17, a frame 3 is formed with a plurality of reamer holes 3e. Further, a high and low pressure separator 4 is formed with reamer holes 4b at positions relative to 3e.

Numeral 16 is stepped pins engaging the reamer holes 3e and 4b. Each stepped pin has a step part larger than the reamer hole diameter at the part corresponding to the axial dimension between the frame 3 and the high and low pressure separator 4.

The reamer holes 3e and 4b and the stepped pins 16 enable easy determination of diametric and axial positions of the frame 3 and the high and low pressure separator 4, >.t - 47 improving assembly workability and accuracy. Embodiment 8:

Figure 18 is a longitudinal sectional view of the main part showing anotIher embodiment ofthe invention, wherein numeral 9 is a sealed vessel and numeral 1 is a fixed scroll provided with a base plate lb placed to one end face 9a in the sealed vessel 9 and disposed displacably in a central axial direction of the sealed vessel 9, a fixed scroll plate-like spiral tooth la formed on the side of the base plate lb opposed from the end face ga, and a discharge port le placed at the center of the base plate lb.

Numeral 2 is an orbiting scroll provided with an orbiting scroll platelike spiral tooth 2a disposed on a base plate 2c facing the fixed scroll plate-like spiral tooth la and engaging the fixed scroll plate-like spiral tooth la for forming a compression space 21 and a boss 23 disposed on the side of the base plate 2a opposed from the orbiting scroll plate- like spiral tooth 12.

Numeral 3 is a frame which has an outer peripheral surface fixed in the sealed vessel 9 and is placed on the side of the orbiting scroll 2 opposed from the fixed scroll 1.

Numeral 4 is a high and low pressure separator constituting a stationary member, which is fixed between the fixed scroll 1 and the end face 9a of the sealed vessel 9 and placed facing the base plate lb of the fixed scroll 1 for - >S. - l> k- blocking displacement in a direction in which the fixed scroll 1 approaches the end face 9a at a predetermined position. Numeral 4f is a discharge port which is disposed at the center of the high and low pressure separator 4 and placed concentrically with the discharge port le of the fixed scroll 1 and has a bore larger than the bore of the discharge port le of the fixed scroll 1.

Numeral 10 is a seal member provided between the high and low pressure separator 4 and the base plate lb of the fixed scroll 1. Numeral 11 is a seal member provided between the high and low pressure separator 4 and the base plate 1b of the fixed scroll 1 and placed outside the seal member 10. Numeral 22 is a high pressure chamber formed in the discharge port 4f of the high and low pressure separator 4.

Numeral 4a is an intermediate pressure chamber, i.e. a back pressure chamber, formed between the seal members 10 and 11 provided between the high and low pressure separator 4 and the base plate lb of the fixed scroll 1.

Numeral 24 is a low pressure chamber formed between the sealed vessel 9 and outside of the fixed scroll 1 and the orbiting scroll 2.

Numeral ld is an extraction hole formed in the base plate lb of the fixed scroll 1 and communicated with the compression space 21 and the back pressure chamber 4a. Numeral 7 is an Oldhamls coupling disposed between the base plate 2c of the orbiting scroll 2 and the frame 3 for - j;-C- Aro restraining the rotation of the orbiting scroll 2 and positioning the orbiting scroll 2 and the frame 3.

The scroll compressor having the structure also operates like the scroll compressor in Figure 23 and compresses a refrigerant gas. The discharge port 4f which is placed concentrically with the discharge port le of the fixed scroll 1 and has a bore larger than the bore of the discharge port le of the fixed scroll 1 is disposed at the center of the high and low pressure separator 4.

Thus, when the refrigerant gas is discharged, flow passage resistance lessens, decreasing a pressure loss. Therefore, a problem in which a pressure loss, etc., increases due to a complicated flow passage form, lowering the compression efficiency, can be solved, improving the compression efficiency.

A scroll compressor is available which is provided with the high and low pressure separator 4 for simply preventing heat from being leaked from the high pressure chamber 22 to the compression space 21. In such a structure, the scroll compressor structure in Figure 18 can also be applied for lessening the flow passage resistance when the refrigerant gas is discharged, thereby improving the compression efficiency.

SD Embodiment.9:

Figure 19 is a longitudinal sectional view of the main part showing another embodiment of the invention. Parts identical with or similar to those previously described with reference to Figure 18 are denoted by the same reference numerals in Figure 19. In Figure 19, numeral 28 is a pressure release device made up of a relief port 29 disposed in a high and low pressure separator 4 and an opening/closing valve 30 placed facing the relief port 29.

The scroll compressor having the structure also operates like the scroll compressor in Figure 23 and compresses a refrigerant gas. The relief port 29 disposed in the high and low pressure separator 4 has a center located in a position substantially matching the center of an extraction hole ld of a fixed scroll 1. Thus, the pressure transmission path from the extraction hole id to the pressure release device 28 shortens and the relief port 29 and the extraction hole 30 match in the pressure transmission direction on the pressure transmission path.

Therefore, if pressure in a back pressure chamber 4a abnormally rises, the pressure release device 28 releases the pressure in the back pressure chamber 4a without delay at the same time as the pressure abnormally rises. Thus, the pressure in the back pressure chamber 4a producing a force pressing the fixed scroll 1 against an orbiting scroll 2 does not abnormally rise at any time, thereby preventing the press - JM - force acting on the orbiting scroll 2 from becoming excessive, promoting tooth tip wear of a fixed scroll platelike spiral tooth la and an orbiting scroll plate-like spiral tooth 2a, and damaging them; failure occurrence can be decreased, improving operation reliability.

The produce the following effects:

An outer peripheral portion of the base plate of the fixed scroll is radially supported by a circular cylinder of the stationary member, which circular cylinder is coaxial with the outer peripheral portion of the base plate of the fixed scroll, and the outer peripheral portion of the fixed scroll is axially slidable along the circular cylinder of the stationary member as a guide within a range in which one axial end thereof interferes with the orbiting scroll and the other axial end thereof interferences with the stationary member. Thus, the place where the fixed scroll is radially supported (the outer peripheral portion of the fixed scroll) is near the radial load acting position of the fixed scroll, so that a high-efficiency and high-reliability scroll compressor with little moment making the fixed scroll unstable can be provided. Since the axial downward position regulation member of the fixed scroll is an orbiting scroll, tooth tip leakage gap is substantially zero; a highefficiency scroll compressor can be provided.

Rotation of the fixed scroll with respect to the stationary member is regulated by rotation direction - ->k - -22 - regulation means, and the outer peripheral portion of the base plate of the fixed scroll and the rotation direction regulation means are disposed to almost match in axial position. Thus, the axial position supporting a radial load of the fixed scroll matches the axial position restraining rotation (on which couple acts); a high-reliability scroll compressor free from a moment causing unstable behavior of the fixed scroll can be provided.

Rotation of the fixed scroll with respect to the stationary member is regulated by rotation direction regulation means, and a clearance between the fixed scroll and the rotation direction regulation means is made larger than a clearance between the outer peripheral portion of the base plate of the fixed scroll and a sliding portion.of the circular cylinder of the stationary member. Thus, the radial load acting on the fixed scroll basically is supported on the outer periphery of the base plate; an excessive load does not act on the rotation regulation means and operability is also good. Therefore, a high-efficiency and highreliability scroll compressor can be provided.

The seal member is disposed in the clearance between the stationary member and the fixed scroll at a set portion which is formed on a plane parallel with the base plate of the fixed scroll. Thus, in assembling, the fixed scroll is not diametrically restrained at the seal position; a low-cost scroll compressor excellent in an assembly property can be - 80 n > provided. In addition, clearance imbalance of seal place caused by assembly failure does not occur either; a highefficiency and highreliability scroll compressor good in a seal property can be provided.

Since a seal member disposed in a clearance between the stationary member and the fixed scroll is in the form of a ring having a joint, the joint can absorb dimensional variation. Thus, the sealing property can be assured, and a high-efficiency and high-reliable scroll compressor can be provided.

An elastic member which, when set into a ring-like configuration, defines a slope surface decreasing in height from an inner peripheral side thereof to an outer peripheral side thereof and produces a force to enlarge the ring-like configuration, wherein the seal member is mounted onto the slope surface. Thus, at a stop condition of the scroll compressor, the elastic member attempts to enlarge radially outwardly due to its elasticity, so that the seal member is raised upwardly by the slope surface and depressed outwardly thereby, whereby it is lightly depressed against a wall surface of a groove accommodating seal member. If the compressor starts under this condition, intermediate pressure and high pressure are both sealed immediately after the start, so that the high pressure are sent behind the seal member, and the seal member is surely brought into pressure contact with the stationary member and the inner wall of the - k I,)+ seal member accommodation groove. Accordingly, the sealing property can be assured, and a high-efficient and highreliable scroll compressor can be provided.

An area onto which discharge pressure behind the fixed scroll is applied is substantially as large as a discharge port area. The force which depresses the fixed scroll against the orbiting scroll at the vacuum operation condition can be made relatively small. Thus, high-reliable scroll compressor free from damage of tooth tips can be provided.

Extraction holes for communicating an intermediate pressure chamber behind the fixed scroll with a compression space defined by the plate- like spiral teeth are provided for paired two pressure chambers, respectively. Thus, an abnormal rotation moment does not occur in the fixed scroll or the orbiting scroll, providing a high-reliability scroll compressor wherein rotation restraint means such as the Oldham's coupling and rotation regulation means are not damaged due to an excessive load.

A second interference member other than the orbiting scroll for regulating an axial (downward) travel distance of the fixed scroll on the plate-like spiral tooth side of the fixed scroll is provided. Thus, even if the tooth tips of the plate-like spiral teeth wear, the fixed scroll interferes with the second interference member when the distance between the base plate of the fixed scroll and the base plate of the - a: 21 - orbiting scroll becomes slightly short, whereby the pressing force to.the tooth tips of the plate-like spiral teeth decreases, and wear development of the tooth tips is stopped. Therefore, a stable-performance scroll compressor wherein the stroke volume of the compressor does not decrease with use can be provided; in addition, a high-reliability scroll compressor as the entire air conditioner with few amount of sludge occurrence can be provided.

An outer peripheral portion of the base plate of the fixed scroll is supported by a circular cylinder of a stationary member, and the second interference member is made up of an upper end face of an outer peripheral wall of the frame, which interferes with a part of the outer peripheral portion of the base plate of the fixed scroll. Thus,..even though the fixed scroll is axially moved along the circular cylinder of the stationary member as a guide so that the tip of plate-like tooth experiences wearing, the outer periphery of the base plate of the fixed scroll interferes with the upper end face of the outer peripheral wall of the frame when the distance between the base plate of the fixed scroll and the base plate of the orbiting scroll becomes slightly short, whereby the pressing force to the tooth tips of the platelike spiral teeth decreases, and wear development of the tooth tips is stopped. Therefore, a stable-performance scroll compressor wherein the stroke volume of the compressor does not decrease with use can be provided; in addition, a 5( high-reliability scroll compressor as the entire air conditioner with few amount of sludge occurrence can be provided.

The fixed scroll is coupled to the frame through a plate spring, the second interference member is made up of an upper end face of an outer peripheral wall of the frame, which interferes with a part of the outer peripheral portion of the base plate of the fixed scroll through the plate spring. Thus, even though the fixed scroll is axially moved so that the tip of plate-like tooth experiences wearing, the outer periphery of the base plate of the fixed scroll interferes with the upper end face of the outer peripheral wall of the frame when the distance between the base plate of the fixed scroll and the base plate of the orbiting scroll becomes slightly short, whereby the pressing force to the tooth tips of the plate-like spiral teeth decreases, and wear development of the tooth tips is stopped. Therefore, a stable-performance and highreliability scroll compressor can be provided.

In a scroll compressor having a frame coupled to a fixed scroll through a plate spring, the plate spring and the fixed scroll or the plate spring and the frame are fastened by means of a reamer bolt, or the plate spring and the fixed scroll or the plate spring and the frame are fastened by means of a reamer pin and a bolt. Thus, even if an excessive load acts on the fixed scroll at the liquid compression - >4 5-7 operation, etc., the fixed scroll and the frame are not detached-and phase shift and diametric gap that cannot be followed do not occur, providing a high-efficiency and highreliability scroll compressor.

Since the plate spring and the fixed scroll or the plate spring and the frame are fastened by at least two reamer bolts or two reamer pins, even if an excessive load acts on the fixed scroll at the liquid compression operation, etc., the fixed scroll and the frame are not detached, providing a high-efficiency and high-reliability scroll compressor.

In a scroll compressor wherein a fixed scroll and a plate spring are coupled together through a plate spring, and the fixed scroll capable of making minute axial motion with axial direction compliance means, the plate spring is fixed to a face of a spiral side of the base plate of the fixed scroll. The scroll compressor becomes free from need to elongate the base plate downwardly which has been required in case where it is fixed to a opposite face from the spiral side. Thus, the volume of the fixed scroll can be lessened and the axial minute follow-up operability of the fixed scroll becomes good, providing a high-performance and highreliability scroll compressor which well follows a form error of the parts and does not delay in relief at the relief time.

In a scroll compressor wherein a fixed scroll and a frame are coupled together through a plate spring, and the - J3; - fixed scroll is capable of making minute axial motion with axial direction compliance means, one of the plate springs is fastened to a face, oriented in a spiral direction, of an outer periphery of the base plate of the.fixed scroll by a bolt, whereas the other is fastened to an upper end face of a frame outer peripheral wall surrounding the fixed scroll spiral substantially over its overall height by a bolt, and, further, relief parts are provided at corresponding points of the base plate of the fixed scroll and an upper end face of the frame outer peripheral wall for avoiding interference of heads of the fastening bolts. Thus, the interference with the heads of the fastening bolts can be prevented by the relief parts, and the fixed scroll can be made small in volume. The axial minute follow-up operability of the fixed scroll becomes good.

Since the relief parts include a notch, spot facing, or equivalent provided on an outer peripheral portion of the fixed scroll and a notch, spot facing, or equivalent recess provided on the upper end face of the frame outer peripheral wall, they are formed easily and the fixed scroll can be made small.

In a scroll compressor wherein a fixed scroll and a frame are coupled together through a plate spring, and the fixed scroll is capable of making minute axial motion with axial direction compliance means, relative positioning of the fixed scroll and the frame when to be assembled together is -:56 - 59 ensured by inserting reamer pins into reamer holes formed respectively in the fixed scroll and the frame. Accordingly, the fixed scroll and the frame (thus, the orbiting scroll) can be assemble together with the phase therebetween be determined with high accuracy, and thus a high-efficiency scroll compressor with a small leakage gap in radial direction of a compression space can be provided.

In a scroll compressor wherein a space between the fixed scroll and the stationary member is divided by a seal member, and compressed gas from a compression space applies pressure onto a pressure seal face of the fixed scroll to energize the fixed scroll toward the orbiting scroll, the stationary member is welded to the sealed vessel near an axial position of the pressure seal face, whereby the bend moment produced by the shrinkage force by welding that acts on the seal plane can be reduced and seal plane deformation can be decreased for providing a scroll compressor which is highly reliable in the seal part.

In a scroll compressor provided with a high and low pressure separator fixed to a sealed vessel and a plate spring through which a fixed scroll and an orbiting scroll are coupled together, an axial (upward) travel distance of a side of the fixed scroll opposite from a plate-like spiral tooth side is regulated by interference with the high and low pressure separator or a member attached to the high and low pressure separator. Thus, a strong upward collision of the - P - Go fixed scroll occurring at the liquid compression time, etc., is received at the high and low pressure separator, providing a high-reliability scroll compressor wherein damage to the parts or parts fastening failure is not caused by a collision.

In case a high and low pressure separator regulating an axial (upward) travel distance of a side of the fixed scroll opposite from a plate-like spiral tooth side is to be fixed to the sealed vessel, the high and low pressure separator is axially positioned by pressing it against the frame or a member attached to the frame. Thus, the distance between the high and low pressure separator and the fixed scroll can be easily managed with high accuracy, providing a high-reliability scroll compressor wherein the parallelism of the high and low pressure separator and the fixed scroll can be well managed and a single hit when the fixed scroll collides with the high and low pressure separator is prevented. Further, since the travel distance of the fixed scroll is managed accurately, a high-reliability scroll compressor can be provided wherein trouble such that the maximum relief amount is too excessive to provide a compression function at starting does not occur.

In a scroll compressor provided with a stationary member disposed at an opposite side of a fixed scroll with respect to an orbiting scroll, and a plate spring through which the fixed scroll and a frame are coupled together, the G rear of the fixed scroll is brought into close contact with the stationary member by an initial pressing force of the plate spring at operation stop state and no intermediate chamber is provided. Thus, the fixed scroll is not strongly pressed against the orbiting scroll just after the compressor is started normally or with full liquid; a low-noise and high-reliability scroll compressor which starts slowly is provided.

A plate spring connecting a fixed scroll to a frame includes a number of sheet members laminated axially one on another. Thus, a large compression capacity scroll compressor which can maintain a good axial relief characteristic even if the plate spring strength is increased can be provided.

In a scroll compressor having a plate spring connecting a fixed scroll to a frame, the plate spring is sandwiched between an inner peripheral side step part on a plate spring attachment face of the base plate of the fixed scroll and an inner wall face of a sealed shell to regulate diametric displacement. Since the plate spring is sandwiched between the inner peripheral side step part on the plate spring attachment face of the base plate of the fixed scroll and the inner wall face of the sealed shell to regulate diametric displacement, the plate spring does not shift even in an operation condition in which an excessive load acts on the spiral at the liquid compression time, etc., and thus a - OR - G2- scroll compressor which does not lower in performance or noise characteristic can be provided.

A stationary member for regulating axial movement of the fixed scroll toward a side opposite from the plate-like spiral tooth of the fixed scroll is provided, and axial dimensions of spiral teeth of the fixed scroll and the orbiting scroll are set so that a tip of the spiral tooth of the fixed scroll comes in contact with a bottom of the spiral tooth of the orbiting scroll while a tip of the spiral tooth of the orbiting scroll and a bottom of the spiral tooth of the fixed scroll have a minute axial gap during operation. Thus, even if material whose wear easily develops is used for the orbiting scroll, the spiral tooth tips can be prevented from wearing and the orbiting scroll weight can be reduced.

In a scroll compressor in which a fixed scroll is coupled to a frame through a plate spring, and which is provided with a stationary member for regulating axial movement of the fixed scroll toward a side opposite from the plate-like spiral tooth of the fixed scroll, the scroll compressor is further provided with means for axially and diametrically positioning the stationary member and the frame. Thus, a high-reliability scroll compressor wherein accurate positioning can be performed and an assembly error can be prevented can be provided.

The axial and diametric positioning means for the stationary member and the frame comprise a plurality of - -%Q - reamer holes formed in a high and low pressure separator, reamer holes formed in the frame at positions corresponding to the reamer holes of the high and low pressure separator, and stepped pins inserted in respective reamer holes. Thus, axial and diametric positioning of the high and low pressure separator and the frame can be performed at the same time for improving assembly.

A discharge port of a stationary member disposed at an opposite side of the fixed scroll with respect to the orbiting scroll is arranged coaxial with respect to a discharge port of a fixed scroll and lager in diameter than the discharge portion of the fixed scroll. Thus, the discharge flow passage of a refrigerant gas defined by the discharge ports of the fixed scroll and the stationary member is simplified, so that the flow passage resistance when a refrigerant gas is discharged lessens, decreasing the pressure loss. Thus, a problem of lowering the compression efficiency due to a pressure loss when a refrigerant gas is discharged is solved, improving compression efficiency. In a scroll compressor having axial direction compliance means, since a

fixed scroll is capable of making minute axial motion with the axial direction compliance meansf and a discharge port of a stationary member disposed at an opposite side of the fixed scroll with respect to the orbiting scroll is arranged coaxial with respect to a r discharge port of the fixed scroll and lager in diameter than JC G + the discharge portion of the fixed scroll, the discharge flow passage of a refrigerant gas defined by the discharge ports of the fixed scroll and the stationary member is simplified, so that the flow passage resistance when.a refrigerant gas is discharged lessens, decreasing the pressure loss.

A stationary member is disposed at an opposite side of the fixed scroll with respect to the orbiting scroll for prohibiting displacement of the fixed scroll away from the orbiting scroll beyond a predetermined position, and the stationary member is provided with a pressure release device made up of a relief port having a center in alignment with a center of an extraction hole arranged in the fixed scroll and a valve for opening and closing the relief port. The pressure transmission path from the extraction hole to the pressure release device shortens and the relief port and the extraction hole match in the pressure transmission direction on the pressure transmission path. Thus, if the pressure in the back pressure chamber between the high and low pressure separator and the fixed scroll abnormally rises, the pressure release device operates without delay. This effect can prevent the press force acting on the orbiting scroll from becoming excessive when the pressure in the back pressure chamber abnormally rises, promoting tooth tip wear of the fixed spiral tooth and the orbiting spiral tooth, and damaging them; operation reliability is improved.

Claims

Claims:

1. A scroll compressor comprising in a sealed vessel having an inlet and an outlet: a non-orbital scroll with a plate-like spiral- tooth on one side of a base plate; an orbital scroll with a plate-like spiral tooth, of substantially the same form as the spiral tooth of the non-orbital scroll, on one side of a base plate and a shaft or a bearing for receiving a driving force on the opposite side of the base plate, the orbital scroll executing orbiting motion with respect to the non-orbital scroll; a frame, fixedly mounted to the sealed vessel, for axially supporting the orbital scroll and radially supporting a drive shaft, the frame being coupled to the non-orbital scroll through a plate spring; and a high and low pressure separator located at the opposite side of the non- orbital scroll with respect to the orbital scroll and fixed to the sealed vessel, wherein: axial travel of the non-orbital scroll away from the orbital scroll is limited by interference of the side of the non-orbital scroll opposite to the spiral tooth side with the high and low pressure separator or a member attached to the high and low pressure separator.

2. A scroll compressor as claimed in claim 1, wherein, when the high and low pressure separator is to be fixed to the sealed vessel, the high and low pressure separator is axially positioned by pressing it against the frame or a member attached to the frame.

3. A scroll compressor as claimed in claim 1, wherein: an outer peripheral portion of the base plate of the non-orbital scroll is radially supported by a circular cylinder of the high and low pressure 66 separator, the circular cylinder being coaxial with the outer peripheral portion of the base plate of the non-orbital scroll; and the said outer peripheral portion of the base plate of the non-orbital scroll is axially slidable along the said circular cylinder, which acts as a guide, within a range limited by interference of one axial end of the said base plate with the orbital scroll and interference of the other axial end with the said separator or the said member attached thereto.

4. A scroll compressor as claimed in claim 3, wherein rotation of the nonorbital scroll with respect to the said separator is restrained by rotation direction regulation means, and the outer peripheral portion of the base plate of the non-orbital scroll and the rotation direction regulation means are disposed to substantially match in axial position.

5. A scroll compressor as claimed in claim 3, wherein rotation of the nonorbital scroll with respect to the said separator is restrained by rotation direction regulation means, and a clearance between the nonorbital scroll and the rotation direction regulation means is made larger than a clearance between the outer peripheral portion of the base plate of the non-orbital scroll and a sliding portion of the circular cylinder of the stationary member.

6. A scroll compressor as claimed in claim 1, wherein: a seal member is disposed in a clearance between the said separator and the fixed nonorbital scroll to form a pressure portion which presses the non-orbital scroll toward the orbital scroll, the non-orbital scroll being capable of minute axial motion; and the seal member is disposed in the clearance between the stationary member and the non-orbital scroll at a set portion of the clearance lying in a plane parallel with the base plate of the nonorbital scroll.

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7. A scroll compressor as claimed in claim 1, wherein a seal member is disposed in a clearance between the said separator and the non-orbital scroll to form a pressure portion which presses the non-orbital scroll toward the orbital scroll, the fixed scroll being capable of minute axial motion, the seal member being in the form of a ring having ajoint.

8. A scroll compressor as claimed in claim 7, including an elastic member set into a ring-like configuration, which defines a slope surface decreasing in height from an inner peripheral side thereof to an outer peripheral side thereof and produces a force to enlarge the ring-like configuration, the seal member being mounted on the slope surface.

9. A scroll compressor as claimed in claim 1, wherein an area onto which discharge pressure behind the non-orbital scroll is applied is substantially as large as a discharge port area.

10. A scroll compressor as claimed in claim 1, wherein extraction holes for communicating an intermediate pressure chamber behind the nonorbital scroll with a compression space defined by the spiral teeth are provided for paired pressure chambers, respectively.

11. A scroll compressor as claimed in claim 1, including a second interference member, other than the orbital scroll, for regulating axial (downward) travel distance of the non-orbital scroll on the spiral tooth side of the non-orbital scroll.

12. A scroll compressor as claimed in claim 11, wherein outer peripheral portion of the base plate of the non-orbital scroll is supported by a circular cylinder of the said separator, and the second separator interference member is constituted by an upper end face of an outer peripheral wall of 68 the frame, which interferes with a part of the outer peripheral portion of the base plate of the non-orbital scroll.

13. A scroll compressor as claimed in claim 11, wherein the second interference member is constituted by an upper end face of an outer peripheral wall of the frame, which interferes with a part of the outer peripheral portion of the base plate of the non-orbital scroll through the plate spring.

14. A scroll compressor as claimed in claim 1, wherein the plate spring and the non-orbital scroll or the plate spring and the frame are fastened by means of a reamer bolt or a reamer pin, or the plate spring and the nonorbital scroll or the plate spring and the frame are fastened by means of a reamer pin and a bolt.

15. A scroll compressor as claimed in claim 14, wherein the plate spring and the non-orbital scroll or the plate spring and the frame are fastened by at least two reamer bolts or two reamer pins.

16. A scroll compressor as claimed in claim 1, wherein the plate spring is fixed to the face of the spiral toothed side of the base plate of the non-orbital scroll.

17. A scroll compressor as claimed in claim 1, wherein: the frame is coupled to the non-orbital scroll through a plurality of plate springs; one of the plate springs is fastened by a bolt to a face, oriented in a spiral direction, of an outer periphery of the base plate of the nonorbital scroll; 69 the other is fastened by a bolt to an upper end face of a frame outer peripheral wall surrounding the non-orbital scroll spiral tooth substantially over its overall height; and relief parts are provided at corresponding points of the base plate of the non-orbital scroll and an upper end face of the frame outer peripheral wall for avoiding interference of heads of the fastening bolts.

18. A scroll compressor as claimed in claim 17, wherein the relief parts include a notch, spot facing, or equivalent recess provided on an outer peripheral portion of the non-orbital scroll and a notch, spot facing, or equivalent recess provided on the upper end face of the frame outer peripheral wall.

19. A scroll compressor as claimed in claim 1, wherein relative positioning of the non-orbital scroll and the frame when to be assembled together is ensured by inserting reamer pins into reamer holes formed respectively in the non-orbital scroll and the frame.

20. A scroll compressor as claimed in claim 1, wherein: a seal member divides a space between the non-orbital scroll and the said separator; compressed gas from a compression space applies pressure onto a pressure seal face of the non-orbital scroll to urge the non-orbital scroll toward the orbital scroll; and the said separator is welded to the sealed vessel near an axial position of the pressure seal face.

21. A scroll compressor as claimed in claim 1, wherein the rear of the non-orbital scroll is brought into close contact with the said separator by an initial pressing force of the plate spring under an operation stop state to provide no intermediate chamber.

22. A scroll compressor as claimed in claim 1, wherein the plate spring comprises a plurality of sheet members laminated axially one on another.

23. A scroll compressor as claimed in claim 1, wherein the plate spring is sandwiched between an inner peripheral side step part on a plate spring attachment face of the base plate of the non-orbital scroll and an inner wall face of a sealed shell to regulate diametric displacement.

24. A scroll compressor as claimed in claim 1, wherein the axial dimensions of the spiral teeth of the scrolls are set so that a tip of the spiral tooth of the non-orbital scroll comes in contact with a bottom of the spiral tooth of the orbital scroll while a tip of the spiral tooth of the orbital scroll and a bottom of the spiral tooth of the non-orbital scroll have a minute axial gap during operation.

25. A scroll compressor as claimed in claim 1, including means for axially and diametrically positioning the high and low pressure separator and the frame.

26. A scroll compressor as claimed in claim 25, wherein the axial and diametric positioning means comprise a plurality of reamer holes formed in the high and low pressure separator, reamer holes formed in the frame at positions corresponding to the reamer holes of the high and low pressure separator, and stepped pins inserted in respective reamer holes.

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27. A scroll compressor as claimed in claim 1, wherein the said separator has a discharge port coaxial with a discharge port of the non-orbital scroll and larger in diameter.

28. A scroll compressor as claimed in claim 1, wherein the said separator i s provided with a pressure release device made up of a relief port in register with an extraction hole in the non-orbital scroll and a valve for opening and dosing the relief port.

29. A scroll compressor as claimed in claim 1, substantially as herein described.