JP2009257146A - Scroll fluid machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scroll fluid machine capable of improving durability, wear resistance and volumetric efficiency of a scroll unit. <P>SOLUTION: An end plate 26 of a movable scroll 22 provided in the scroll fluid machine 1 has a projecting section 46 which partially projects outward from an outer periphery of the end plate and increases a sliding area for an end plate 28 of a fixed scroll 24 with respect to an end plate surface 26a of the end plate, wherein the projecting section is provided between -180° and 90° in terms of an involute angle from a volute termination 30a at the outermost periphery of a wrap 30 of the movable scroll. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a scroll type fluid machine, and more particularly, to a scroll type fluid machine suitable for being incorporated in a refrigeration air conditioner or a heat pump type water heater.

This type of scroll type fluid machine, for example, a hermetic type scroll compressor, performs a series of processes of sucking, compressing and discharging a working fluid including lubricating oil by revolving orbiting the movable scroll with respect to the fixed scroll in the housing. A scroll unit is provided.
Specifically, spiral wraps are provided on the end plate surfaces of the movable and fixed scroll end plates, and the wraps cooperate to form a compression chamber for the working fluid between the wraps. The above-described series of processes is performed by moving toward the innermost periphery while reducing the volume.

In Patent Document 1, a movable scroll end plate is provided with a projecting portion that partially protrudes outward from the outer periphery of the end plate, thereby preventing the movable scroll from dropping and the resulting movable scroll damage and noise. Are disclosed.
JP 2001-317474 A

  However, the above-mentioned prior art is to prevent the movable scroll from falling down so that the overhanging portion does not come off the thrust surface of the fixed scroll at the turning position of the active scroll, and the fixed scroll with respect to the end plate surface of the end plate of the movable scroll. No special consideration has been given to the relationship between the sliding area of the end plate and the amount of wear of the end plate of the movable scroll, and the durability and wear resistance of the movable scroll and consequently the scroll unit are included in the working fluid. There remains a problem with improving the volumetric efficiency of the compressor by reducing the leakage of lubricating oil from the compression chamber.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a scroll type fluid machine capable of improving the durability and wear resistance of the scroll unit and further its volumetric efficiency. .

  In order to achieve the above object, the scroll type fluid machine according to claim 1 is an asymmetrical fixed and movable scroll in which spiral wraps based on a predetermined involute curve are paired on the end plate surface of the end plate. The movable scroll revolves with respect to the fixed scroll to form a compression chamber for working fluid containing lubricating oil between the laps, and the compression chamber reduces its volume toward the innermost periphery of the wrap. A scroll type fluid machine that moves while the end plate of the movable scroll has a protruding portion that partially protrudes outward from the outer periphery of the end plate to increase the sliding area of the end plate of the fixed scroll with respect to the end plate surface of the end plate The overhanging portion is provided between the end of the spiral in the outermost peripheral portion of the wrap of the movable scroll and the involute extension angle between −180 ° and 90 °. It is characterized by that.

The invention according to claim 2 is characterized in that, in claim 1, a plurality of overhang portions are provided.
Further, according to the invention of claim 3, in the first aspect of the invention, the end plate of the fixed scroll is provided with a suction portion from which working fluid is sucked from the outside when the compression chamber is formed, and the overhanging portion is formed in the radial direction of the suction portion. It is characterized by being provided in an arc shape on the outer peripheral side.

Furthermore, in the invention according to claim 4, in claim 3, the overhanging portion is provided in an arc shape also in the vicinity of the position of -90 ° at the involute extension angle from the radially outer peripheral side of the suction portion. It is characterized by.
According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the movable scroll has a cylindrical portion in which the radial direction of the end plate is chuck-fixed from the opposite side of the end plate surface during the processing. Is characterized in that it is projected from the height position where the fixing margin enabling the chuck fixing in the cylindrical portion is left to the height position of the end plate surface.

  According to the scroll type fluid machine of the present invention as set forth in claim 1, the end plate of the movable scroll partially protrudes outward from the outer periphery of the end plate to enlarge the sliding area of the end plate of the fixed scroll with respect to the end plate surface. Part. In particular, by providing the overhanging portion between the end of the spiral at the outermost peripheral portion of the movable scroll wrap and the involute extension angle from −180 ° to 90 °, the end plate of the fixed scroll slides on the end plate surface of the movable scroll. Since it is possible to increase the area of the end plate where the area is relatively small and secure the sliding area, it is possible to reduce wear of the end plate surface that occurs intensively at this location. Accordingly, the durability and wear resistance of the movable scroll, and hence the scroll unit, can be improved, and further, leakage of the lubricant contained in the working fluid from the compression chamber can be reduced. Volumetric efficiency can be improved.

According to the invention of claim 2, even if there are a plurality of locations where the sliding area becomes relatively small by providing a plurality of overhang portions, the area of the end plate is locally increased accordingly. The sliding area can be ensured by enlarging.
Specifically, according to the invention described in claim 3, the overhanging portion is provided in an arc shape on the radially outer peripheral side of the working fluid suction portion, and further, according to the invention described in claim 4, From this position, an arcuate shape is also provided in the vicinity of the position of −90 ° at the involute extension angle. Since these locations are locations where the sliding area of the end plate of the fixed scroll with respect to the end plate surface of the movable scroll is relatively small and the wear amount of the end plate is also relatively large, an overhanging portion should be provided at these locations. Thus, the durability and wear resistance of the movable scroll, and consequently the scroll unit, can be effectively improved, and the volume efficiency of the scroll type fluid machine can be further improved, which is preferable.

  Furthermore, according to the invention described in claim 5, the projecting portion is projected from the height position of the end plate leaving the fixing margin enabling the chuck fixing in the cylindrical portion to the height position of the end plate surface, Since the overhanging portion can be formed without changing the end plate processing method or processing step, the durability and wear resistance of the movable scroll, and hence the scroll unit, can be improved easily. It is preferable because the volumetric efficiency of can be improved.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view of a hermetic scroll compressor as an example of a scroll type fluid machine according to the present embodiment. The compressor 1 is incorporated in a refrigeration circuit such as a refrigeration air conditioner or a heat pump type hot water heater. It is. The circuit includes a path through which a carbon dioxide refrigerant (hereinafter referred to as a refrigerant), which is an example of a working fluid, circulates including lubricating oil, and the compressor 1 sucks the refrigerant from the path, compresses it, and discharges it toward the path. To do.

  The compressor 1 includes a shell 2, and a center shell 4 that forms a cylindrical body of the shell 2 is hermetically fitted with an upper side and a lower side by a top shell 6 and a bottom shell 8, respectively, and the inside of the center shell 4 is hermetically sealed. The discharge pressure of the refrigerant is acting. The center shell 4 is connected to a suction pipe 10 for sucking the refrigerant taken in from the circuit, and a discharge pipe 12 for sending the compressed refrigerant in the shell 2 to the circuit is connected to an appropriate position of the top shell 6. .

  In the center shell 4, a scroll unit 14, an electric motor 16, and a pump unit 18 are accommodated in this order from above, and a rotating shaft 20 is disposed in the electric motor 16, and the rotating shaft 20 is energized by energizing the electric motor 16. Driven by rotation. The rotary shaft 20 has an upper end connected to the scroll unit 14 and a lower end connected to the pump unit 18, and the rotary shaft 20 is driven to rotate by the electric motor 16, whereby the scroll unit 14 sucks and compresses the refrigerant. On the other hand, the pump unit 18 sucks the lubricating oil stored inside the bottom shell 8 and raises the perforations in the rotary shaft 20, and the scroll unit 14 starts from the upper end of the rotary shaft 20. And supply to bearings.

  Specifically, the scroll unit 14 includes an asymmetric movable scroll 22 and a fixed scroll 24, and the movable scroll 22 includes a mirror plate 26, and a spiral that extends toward the mirror plate 28 of the fixed scroll 24 on the mirror plate surface 26 a of the mirror plate 26. On the other hand, a spiral wrap 32 extending toward the end plate 26 is also set up on the end plate surface 28 a of the end plate 28 of the fixed scroll 24.

  The wraps 30 and 32 are formed on the basis of a predetermined involute curve, and by arranging them in a pair and cooperating with each other, the refrigerant is supplied from the refrigerant suction portion 34 formed on the outer peripheral side of the end plate 12. A compression chamber 36 is formed between the wraps 30 and 32 by suction. The compression chamber 36 moves while reducing its volume from the outer peripheral side in the radial direction of the wraps 30 and 32 toward the innermost peripheral portion of the wraps 30 and 32 by the revolving orbiting motion of the movable scroll 22 relative to the fixed scroll 24. .

A boss 38 is formed on the back side of the end plate 26 to impart a revolving orbiting motion to the movable scroll 22, and the boss 38 is rotatable about an eccentric shaft 40 integrally formed on the upper end side of the rotary shaft 20 via a bearing. It is supported. The rotation of the movable scroll 22 is blocked by a rotation blocking pin (not shown).
On the other hand, the fixed scroll 24 is supported and fixed to the main frame 42 fixed inside the center shell 4, and can communicate with the compression chamber 36 at the center of the fixed scroll 24, which is the innermost peripheral portion of the wrap 32. A discharge hole 44 is formed.

  According to the compressor 1 described above, the revolving and revolving motion of the movable scroll 22 without rotating with the rotation of the rotating shaft 20 causes the refrigerant sucked into the scroll unit 14 via the suction pipe 10 to be compressed. The refrigerant in the compression chamber 36 is compressed while being moved toward the center of the scroll unit 14, is then discharged into the shell 2 through the discharge hole 44, circulates through the shell 2, and then passes through the discharge pipe 12. It is sent out of the compressor 1.

By the way, the end plate 26 of the movable scroll 22 is provided with a projecting portion 46 that partially projects outward from the outer periphery of the end plate 26 and expands the sliding area of the end plate 28 of the fixed scroll 24 with respect to the end plate surface 26a of the end plate 26. ing.
The movable scroll 22 has a cylindrical part 48 in which the radial direction of the end plate 26 is chuck-fixed from the opposite side of the end plate surface 26a during the processing, and the overhanging part 46 is a fixing margin G that enables the cylindrical part 48 to fix the chuck. It protrudes from the height position where the mark is left to the height position of the end plate surface 26a.

  FIG. 2 is a plan view of the scroll unit 14 of FIG. 1 as viewed from a cross section (indicated by oblique lines) in the AA direction of the movable scroll 22. In the case of the present embodiment, the overhanging portion 46 overhangs between −180 ° and 90 ° in the involute extension angle from the involute starting point O positioned at the spiral end 30a in the outermost peripheral portion of the lap 30 of the movable scroll 22. Two portions 46A and 46B are provided.

  One overhanging portion 46A is provided in an arc shape on the radially outer peripheral side of the suction portion 34, and the other overhanging portion 46B is located at a position of −90 ° in the involute extension angle from the vicinity of the outer peripheral side of the suction portion 34. A circular arc is provided in the vicinity. The areas of these overhang portions 46A and 46B are set so as to ensure the same area as the sliding area of the end plate 28 with respect to the end plate surface 26a at locations other than the overhang portions 46A and 46B, and accordingly the arc shapes of the overhang portions 46A and 46B. The shape is also determined.

  As described above, in the present embodiment, the end plate 26 of the movable scroll 22 partially protrudes outward from the outer periphery of the end plate 26 to expand the sliding area of the end plate 28 of the fixed scroll 24 with respect to the end plate surface 26a. It has parts 46A and 46B. In particular, by providing the overhang portions 46A and 46B between the spiral end 30a at the outermost peripheral portion of the lap 30 of the movable scroll 22 and the involute extension angle from −180 ° to 90 °, the end plate surface 26a of the movable scroll 22 is provided. Since the area of the end plate 26a where the sliding area of the end plate 28 of the fixed scroll 24 is relatively small can be enlarged and the sliding area can be secured, the end face 26a that occurs intensively at this location can be secured. Wear can be reduced. Accordingly, the durability and wear resistance of the movable scroll 22 and consequently the scroll unit 14 can be improved, and further, leakage of the lubricating oil contained in the refrigerant from the compression chamber 36 can be reduced. The volumetric efficiency of can be improved.

  The overhanging portion 46A is provided in an arc shape on the radially outer peripheral side of the refrigerant suction portion 34, while the overhanging portion 46B is located at a position of −90 ° from the position of the overhanging portion 46A at the involute extension angle. The vicinity is also provided in an arc shape. These locations are locations where the sliding area of the end plate 28 of the fixed scroll 24 relative to the end plate surface 26a of the movable scroll 22 is relatively small and the amount of wear of the end plate 26 is also relatively large. Providing the overhanging portions 46A and 46B is preferable because it can further improve the durability and wear resistance of the movable scroll 22 and the scroll unit 14, and thus the volume efficiency of the compressor 1.

  Further, since the projecting portions 46A and 46B are projected from the height position of the end plate 26 leaving the fixing margin G that enables the chuck fixing in the cylindrical portion 48 to the height position of the end plate surface 26a, the processing method of the end plate 26 is performed. Further, the overhang portions 46A and 46B can be formed without changing the machining process. Therefore, it is preferable because the durability and wear resistance of the movable scroll 22 and the scroll unit 14 and the volume efficiency of the compressor 1 can be improved.

The description of one embodiment of the present invention is finished above, but the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, two overhang portions 46 are provided as the overhang portions 46A and 46B. However, two or more may be provided, and in any case, a portion where the sliding area is relatively small is locally provided. Even if it covers a plurality, the area of the end plate can be locally enlarged accordingly to ensure a sliding area. Note that only one overhang portion 46 may be provided at the position of the overhang portion 46A, for example.

  Moreover, although the said embodiment demonstrated the compressor 1 of the enclosed scroll using the carbon dioxide refrigerant incorporated in refrigeration circuits, such as a refrigerating air conditioner and a heat pump type hot water heater, this invention is not limited to this and various The present invention can be applied to fluid machines such as compressors and expanders in various fields using the above working fluids.

1 is a longitudinal sectional view showing a hermetic scroll compressor according to an embodiment of the present invention. It is the top view which looked at the scroll unit of FIG. 1 from the cross section of the AA direction of a movable scroll.

Explanation of symbols

1 Compressor (scroll type fluid machine)
DESCRIPTION OF SYMBOLS 22 Movable scroll 24 Fixed scroll 26 End plate 26a End plate surface 28 End plate 28a End plate surface 30 Wrap 30a Spiral termination 32 Wrap 34 Suction part 36 Compression chamber 46 Overhang part 46A Overhang part 46B Overhang part 48 Cylindrical part

Claims (5)

Asymmetric fixed and movable scrolls each having a pair of spiral wraps based on a predetermined involute curve are provided on the end plate surface of the end plate, and the movable scroll revolves with respect to the fixed scroll. A scroll type fluid machine that forms a compression chamber of a working fluid containing lubricating oil between the wraps, and the compression chamber moves toward the innermost peripheral portion of the wrap while reducing its volume,
The end plate of the movable scroll has a projecting portion that partially extends outward from the outer periphery of the end plate to expand the sliding area of the end plate of the fixed scroll with respect to the end plate surface of the end plate,
The scroll fluid machine according to claim 1, wherein the projecting portion is provided between the end of the spiral at the outermost peripheral portion of the wrap of the movable scroll and an involute extension angle of -180 ° to 90 °.   The scroll fluid machine according to claim 1, wherein a plurality of the overhang portions are provided. The end plate of the fixed scroll is provided with a suction portion through which working fluid is sucked from the outside when the compression chamber is formed,
The scroll-type fluid machine according to claim 1, wherein the projecting portion is provided in an arc shape on a radially outer peripheral side of the suction portion.   4. The scroll type fluid according to claim 3, wherein the projecting portion is also provided in an arc shape in the vicinity of a position of −90 ° at an involute extension angle from the radially outer peripheral side of the suction portion. machine. The movable scroll has a cylindrical portion in which the radial direction of the end plate is chuck-fixed from the opposite side of the end plate surface during the processing,
5. The protruding portion according to claim 1, wherein the protruding portion extends from a height position that leaves a fixing margin that enables chucking in the cylindrical portion to a height position of the end plate surface. Scroll type fluid machine.

Images