JPS5853601A - Scroll fluid machine - Google Patents

Abstract

PURPOSE:To complete a sealing function during the process of start by disposing a base seat supporting the outer edge portion of an end plate of a turning scroll on a frame opposing to a wall surface at the non-lapping side of said turning scroll, and by restricting an axial moving distance toward the non-lapping side of said turning scroll. CONSTITUTION:As in cases where pressure conditions are rapidly varied during the process of start, when a pressure of a back pressure chamber 12 can not follow the variation of the pressure in a compression chamber 5a, 5b and an intermediate pressure sufficient to urge a turning scroll member 2 to a stationary scroll member 1 can not be obtained, said member 2 moves to the non- lapping side. At this time, a base seat 9a mounted on a frame 9 makes contact with and slides on the back surface of the outer edge of an end plate 2a of the turning scroll 2. Therefore, the axial moving distance of said member 2 is restricted and a gap between end plates 1a, 2a of laps 1b, 2b and a gap between an outer end of said end plate 2a and an outer end 1e of said stationary scroll 1 are maintained in a slight degree. Accordingly, the sealing function in said back pressure chamber 12 and a suction chamber 16 is maintained and the compression operation is carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a scroll fluid machine used in a refrigerant pressure machine for refrigeration, air conditioning, etc., an air compressor, and an expander such as a Rankine cycle.

Conventionally, in this type of compressor, the back pressure chamber formed on the back surface of the orbiting scroll and the suction chamber were sealed mainly by the outer edge of the orbiting scroll end plate and the outer edge of one plate of the fixed scroll. Therefore, during startup, etc., there is a risk that a sufficient sealing function may not be achieved, resulting in separation of both scroll members or an increase in sliding loss. The purpose is to provide a highly reliable and high-performance fluid machine.

In this type of fluid machine, operations such as compression or expansion are performed stably.The back pressure chamber and suction chamber provided at the back of the orbiting scroll are sufficiently sealed, and the pressure in the back pressure chamber moves the orbiting scroll. Sufficient pressure must be maintained to press against the fixed scroll. For this reason, the configuration of the present invention is such that when sufficient pressure in the back pressure chamber is not obtained, such as during startup, the amount of axial movement of the orbiting scroll is restricted by the pedestal provided in the frame, and the orbiting scroll is fixed to the outer edge of the end plate. The gap with the scroll end plate is kept small to provide a sealing function for the back pressure chamber and the suction chamber.Furthermore, if the pedestal is provided all around the back of the orbiting scroll, the gap between the pedestal and the back of the orbiting scroll end plate can be kept small. A sealing function is obtained, and the pressure in the back pressure chamber is instantaneously maintained at an appropriate pressure according to suction pressure and discharge pressure, resulting in stable compression or expansion.

i When an oil groove or the like is provided in the large pedestal part, an oil retaining function can be obtained, and the characteristics include an increase in sealing force and a reduction in sliding loss.

An embodiment of the present invention will be described below by taking a hermetic scroll compressor as an example.

Figures 1, 2 and 3 show an embodiment of the present invention.

The airtight container 6 consists of three parts 5a, fib, and 5c, and houses the following equipment. The fixed scroll member 1 consists of an end plate 1a and a spiral wrap 1b standing upright on the end plate 1a, and has a suction port IC on the outer periphery and a discharge port 1d in the center. A suction pipe 10 is connected to the suction port 1C, and the discharge port 1d opens into the closed container 6.

The orbiting scroll member 2 consists of an end plate 2a1 and a spiral wrap 2b standing upright on the end plate, and has a boss portion 2C on the surface opposite to the wrap, and two small holes 2d in the end plate 2a.
.

Both wraps 1b, 2b of the crawling member 1.2 are directed inwards and interlock with each other. The frame 9 is connected to the fixed scroll 1 by several bolts (not shown), and includes a back pressure chamber 12. Crank 7ya 7to4 is
It is rotatably supported by a bearing 13 attached to a frame 9. This crankshaft 4 has a pin portion 4 at its end.
a, and the center of the pin portion 4a is located at a distance of a turning radius e from the axis of the crankshaft.

'16, this pin part 4a is connected to the boss part 2 of the orbiting scroll.
It is attached to C.

The rotation prevention member 3 is a flat ring provided with mutually orthogonal grooves on both sides, and is provided between the back surface of the orbiting scroll member 2 and the frame 9.

A key 8 fixed to the frame 9 is fitted into one groove of the rotation prevention member 3, and a key (not shown) fixed to the back surface of the orbiting scroll member 2 is fitted into the other groove #IIK. .

The slurry tough a of the motor 7 is attached to the inner wall surface of the closed container, and the rotor 1b is attached to the crankshaft 4.

Lubricating oil 14 is stored at the bottom of the closed container 6, and is supplied to each layered moving part through an oil tank (not shown) provided in the crankshaft 4. The airtight container 6 has seven frames 9 and a stator 7a fixed to the inner wall by press fitting, welding, etc., and is divided into an upper discharge chamber 21 and a lower motor chamber 22, and a communication passage 15 is provided to connect them. There is.

When the orbiting scroll member 2 rotates in the direction of the hour hand relative to the fixed scroll member 1 due to the rotation of the rotor 1b, the sealed space formed between both end plates tawza and both uppers 1b and 2b moves toward the center of both scrolls. While moving, the volume gradually decreases, the compression chambers 5a and 5b communicate with the discharge port 1d, and the compressed gas is discharged. Discharge port 1d
The compressed gas discharged to the discharge port 21 in the upper part of the hermetic container 6 is sent to the motor chamber 22 in the lower part through the communication passage 15, and after cooling the motor windings, It is delivered to the outside through a pipe 11.

In a scroll fluid device having such a configuration and operation,
A force that attempts to separate the fixed scroll member 1 and the orbiting scroll member 2 in the axial direction acts on both members due to the pressure of the compressed gas existing in the compression chambers 5a and 5b. Because of this, if left as is, both scroll members 1.2 will separate and will no longer be able to perform normal compression, expansion, etc. actions.

For this reason, a back pressure chamber 12 is provided on the back surface of the orbiting scroll 2, and gas pressure is applied to the rear surface of the orbiting scroll 2, thereby applying a large axial force to pull the orbiting scroll member 2 apart. The back pressure chamber 12 is connected to the pressure inside the sealed container 6 by a bearing 13 provided on the frame 9 and the crankshaft 4, and to the pressure in the suction chamber 16 by the outer edge portion 1e of the fixed scroll and the outer edge portion of the orbiting scroll end plate 2a. Under pressure! 1 is in a disconnected state, and 1 orbiting scroll end plate 2aK is provided, and the compression chambers 5a, 5b are formed by the small opening 2d.
Since the compressor 5 is in communication with the chamber in the middle of compression, it is maintained at an intermediate pressure depending on the pressure inside the compressor 5. This intermediate pressure is
The position of the small hole 2d is appropriately set so as to apply an axial pressing force that is slightly larger than the force that attempts to separate the orbiting scroll member 2 from the fixed scroll member 1.

At startup, if the pressure conditions suddenly change, such as at 6 o'clock, the pressure in the back pressure chamber 12 cannot follow the change in pressure in the compression chamber 5, and an intermediate pressure sufficient to press the orbiting scroll member 2 against the fixed scroll member 1 is obtained. If not, the orbiting scroll member 2 moves in the opposite direction.

At this time, the pedestal portion 9a provided on the frame 9 slides in contact with the outer edge back surface of the orbiting scroll end plate 2a. Therefore, the amount of axial movement of the orbiting scroll member 2 is restricted,
A gap between each of the two knobs lb, 2b and each end plate 1atZa caused by movement in the axial direction, and an orbiting scroll end plate 2a
The gap between the outer edge portion and the fixed non-crawl outer edge portion 1e is kept small, and the sealing function between the back pressure chamber 12 and the suction chamber 16 is maintained.
A corrective action takes place.

As time passes, the pressure in the back pressure chamber (intermediate pressure) changes depending on the pressure in the compression chamber, and when the pressure reaches enough to press the orbiting scroll member 2 against the fixed scroll member 1, the orbiting scroll member 2 moves in the wrap direction. , and comes into close contact with the fixed scroll member 1 to perform a normal compression operation.

FIGS. 4, 5, 6, 7, 8, and 9 show other embodiments of the present invention, respectively.

In these embodiments, parts that are the same as or correspond to the above embodiments are designated by the same reference numerals as in FIGS. 1, 2, and 2, and their explanation will be omitted.

In the embodiments shown in FIGS. 4 and 5 and the embodiments shown in FIGS. 6 and 1, the pedestal portion 9a provided on the frame 9 is formed all around the outer edge of the back surface of the end plate of the orbiting scroll member 2,
Regardless of the orbiting movement of the orbiting scroll member 2, the pedestal portion 9m and the back surface of the end plate portion 2a always have an overlapping portion. That is, if the outer diameter of the end plate 2a of the orbiting scroll is 1)so% and the maximum dimension inside the pedestal portion 9a is psi, then the following equation is satisfied.

Dsi (Dso -2g ・・・・・・・・・・・・
(1) When the pressure in the back pressure chamber 12 is not sufficient to press the orbiting scroll member 2 against the fixed scroll member 1, the orbiting scroll member 2 is moved to the opposite side from the lap. The compression operation is performed while the outer edge of the mirror plate 2a slides on the pedestal 9a.

In this case, the back pressure chamber 1
2, and the suction M16 can also obtain a sealing function in the above part,
Pressure is shut off more reliably. For this reason, the back pressure chamber 12
The pressure is maintained at an appropriate pressure depending on the pressure in the compression chamber 5 at one time, and a stable and large compression effect can be obtained.

The embodiments shown in FIGS. 4 and 5 show an annular oil groove 9b in the pedestal, and the embodiments shown in FIGS. 6 and 7 show an embodiment in which an intermittent pocket-shaped oil groove 9C is provided.

As a result, an oil retaining function is obtained, and the orbiting scroll end plate 2
The sealing force between the back surface a and the pedestal portion 9a is increased, and sufficient lubrication with oil is achieved, reducing sliding loss at the pedestal portion.

Note that a plurality of oil grooves may be provided in the radial direction instead of in the vertical direction. Further, even if the pedestal portion 9a does not extend all the way around the entire circumference, providing an oil groove portion provides an oil retaining function and is effective in reducing sliding loss.

Furthermore, a similar effect can be expected even if a portion of the oil is provided on the back surface of the outer edge portion 2a of the end plate of the orbiting scroll that slides on the pedestal portion 9a.

The embodiments shown in FIGS. 8 and 9 show examples in which a recessed portion 9d is provided at the outer edge of the pedestal portion 9a, that is, at the base of the seven frames 9. The recessed portion 9d provides an oil retaining function and can be expected to have the same effect as in the case described above, and when machining the pedestal portion, the recessed portion 9d serves as a relief for the cutter, making it easier to process the pedestal portion 9a. , surface accuracy is improved, and a highly reliable scroll fluid machine can be obtained.

As explained above, according to the present invention, the amount of movement of the orbiting scroll in the axial direction is limited, the back pressure chamber and the suction chamber are sufficiently sealed, and the sliding surfaces are effectively lubricated. Compression or expansion is performed stably regardless of changes in operating conditions, making it possible to obtain a highly reliable and high-performance scroll fluid machine.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a scroll fluid device showing an embodiment of the present invention, FIG. 2 is a sectional view taken along line 1-1 of FIG. 1, and FIG. 3 is a plan view of the frame of FIG. 1. Fig. 4 is a plan view of a frame of another embodiment, and Fig. 5 is a plan view of a frame of another embodiment.
Fig. K6 is a plan view of a frame of still another embodiment, Fig. 7 is a longitudinal sectional view of Fig. 6, Fig. 8 is a plan view of a frame of still another embodiment, Fig. 9 is a longitudinal sectional view of FIG. 8; 1... Fixed scroll member 2... Orbiting scroll member 1a+2''... End plate 1b, 2b...
Wrap 3... Rotation prevention member 4... Crankshaft 5 (5a, 5b)... Compression chamber 6...
・Airtight container 7...Motor 8...Key 9
...Frame 9a...Pedestal part 10...Suction pipe 11...Discharge pipe 12...Back pressure chamber 1
3... Bearing 14... Lubricating oil 15... Communication passage 16... Suction chamber 5□1 'lHIfB

Claims (1)

[Claims] 1. An orbiting scroll formed by standing a spiral wrap upright on an end plate and a stationary scroll member are engaged with each other with the wrap inside, and a rotation prevention means is provided between the orbiting scroll and the stationary member. In a fluid machine, which is equipped with a driving means and a support means for making an orbiting motion of an orbiting scroll, and which compresses or expands a fluid by forming a back pressure chamber at the back of the orbiting scroll, a fluid machine that faces the wall surface on the opposite side of the orbiting scroll. 1. A scroll fluid machine characterized in that the frame is provided with a pedestal portion that supports the outer edge of the end plate of the orbiting scroll to limit the amount of axial movement of the orbiting scroll toward the side opposite to the lap. 2. The scroll fluid machine according to claim 1, wherein the pedestal portion is formed in an annular shape and always has an overlapping portion regardless of movement of the orbiting scroll. 3. The scroll fluid machine according to claim 1 or 2, wherein the pedestal portion is provided with an annular or intermittent pocket-shaped oil groove. 4. The scroll fluid machine according to claim 1 or 2, wherein an annular or intermittent pocket-shaped oil groove is provided on the outer edge of the end plate of the orbiting scroll that slides on the pedestal. 5. The scroll fluid machine according to claim 1, wherein a recess is provided at the base of the pedestal to the frame.