JP2012062763A - Rotary type compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary type compressor 1 of a low production cost capable of preventing a seizure of end faces 6A, 6B of a rotor 6.SOLUTION: The rotary type compressor 1 comprises a pair of closing members 11, 12 for closing opening parts in the front and back sides in the axial direction of a cylinder 5, and a rotor 6 rotated by a motor stored in the cylinder 5. Recesses 11C, 12C of the same depth are formed on the inner wall surfaces 11A, 12A of the closing members 11, 12 so that the recesses 11C, 12C are filled with a synthetic resin coating 22. Thereby, the synthetic resin coating 22 surface and the outward position adjacent thereto (left side in the drawing) of the inner wall surfaces 11A, 12A are on the same surface.

Description

  The present invention relates to a rotary compressor, and more specifically, includes a cylindrical cylinder that houses a rotatable or swingable rotor, and a pair of closing members that close openings at both ends in the axial direction of the cylinder. The present invention relates to a rotary compressor.

Conventionally, a cylinder formed in a substantially cylindrical shape, a pair of closing members for closing openings at both ends in the axial direction of the cylinder, and housed in the cylinder and rotated or rocked in conjunction with a drive shaft A rotary compressor including a rotor is known (for example, Patent Documents 1 to 3).
In such a conventional rotary compressor, the axial dimension of the rotor is set slightly shorter than the axial dimension of the cylinder, and when the assembly of the components of the rotary compressor is completed, the axial direction of the rotor is It is intended that a slight gap is secured between the both end surfaces of each of these and the inner wall surfaces (thrust surfaces) of the respective closing members close to those portions.
In the conventional rotary type compressor, when the refrigerant gas is sucked / discharged into the compression space in the cylinder, a heat receiving / dissipating action is performed between the refrigerant gas and the cylinder, the closing member, etc. There was a drawback that the volumetric efficiency of the rotary compressor was reduced by the heat dissipation action. Thus, for example, Patent Document 2 proposes that a portion facing the compression space in the cylinder, that is, an inner wall surface (thrust surface) of the pair of closing members is covered with a synthetic resin (see FIG. 11). By adopting such a configuration, in the compressor of Patent Document 2, the heat receiving and radiating action between the refrigerant gas supplied to and discharged from the compression space and the inner wall surfaces of the pair of closing members is suppressed, and the compressor It is intended to improve the volumetric efficiency.
By the way, in the compressor of the said patent document 2, since the synthetic resin coating was given over the whole end surface which is an inner wall face of a pair of front and rear closing member, there existed the following problems. That is, as shown in FIG. 11, when the opening portions in the axial direction of the cylinder are closed with a pair of closing members, and the cylinder and both closing members are assembled together with fastening bolts, Since the synthetic resin coating is compressed in the axial direction, the gap α between the axial end surfaces of the rotor and the inner wall surface (synthetic resin coating) adjacent thereto may not be ensured to the extent intended at the beginning. Thus, after the assembly is completed, in a state where the gap between the both end faces of the rotor and the inner wall surface (synthetic resin coating) adjacent to the rotor is not secured to the intended extent, There is a problem that seizure occurs on both end surfaces in the direction and the inner wall surface (synthetic resin coating) in sliding contact therewith.
Therefore, in the compressor of Patent Document 3, in order to prevent seizure between the both end faces of the rotor and the inner wall surfaces of both closing members, the inner parts of both closing members are placed at positions where they are in contact with both end faces in the axial direction of the cylinder. The synthetic resin coating on the wall surface is omitted (see FIG. 12). More specifically, as shown in FIG. 12, in Patent Document 3, an annular notch is formed on the front and rear edges (inner edges of both end faces) in the axial direction on the inner circumferential surface of the cylinder, The radial dimension of the synthetic resin coating of both the closing members is set to a dimension that can be accommodated in the annular notch. With such a configuration, when the cylinder and both closing members are assembled with fastening bolts as shown in FIG. 12, the outer peripheral edges of both synthetic resin coatings are accommodated in the notches, so that the outer peripheral edges are There is no axial compression. Therefore, in the compressor of Patent Document 3, after the assembly is completed, a slight clearance α is ensured between both axial end surfaces of the rotor and the inner wall surface (thrust surface) of the closing member adjacent to them. It is like that.

Japanese Patent No. 3742848 JP 57-49084 A JP 2010-133346 A

However, the compressor of Patent Document 3 also has the following drawbacks. That is, it is assumed that the depth (axial dimension) of the annular notch is slightly larger than the thickness of the synthetic resin coating accommodated therein. Since the depth and the thickness of the synthetic resin coating are actually set to several μm, in the manufacturing process of the component parts of the compressor, the dimensions (depth and outer diameter) of the annular notch and the synthetic resin coating The dimensional management related to the dimensions (thickness, outer diameter) was extremely complicated. In addition, since it is necessary to adjust the dimensional relationship between the notch and the synthetic resin coating in units of several μm in the manufacturing process, there is a disadvantage that the manufacturing cost of the compressor increases accordingly.
In addition, the annular notch is formed to have a depth and an outer diameter that can accommodate the outer peripheral edge of the synthetic resin coating, and therefore the annular notch and the outer peripheral edge of the synthetic resin coating accommodated therein A slight gap X is generated between the two in the radial direction and the axial direction (see FIG. 12). When such a gap X occurs, the refrigerant gas leaks from the high-pressure space to the low-pressure space side through the gap X when the rotor is rotated after the assembly is completed and the compression space in the cylinder is expanded and contracted. As a result, there is a drawback that the compression efficiency is deteriorated when the compressor is operated.
Further, in the compressor of Patent Document 3, the outer peripheral edge of the synthetic resin coating rises more than the inner wall surface (end surface) of the original closing member, resulting in a step. Therefore, in the process of assembling the cylinder and both closing members, first, it is necessary to align the cylinder with both closing members. At that time, a step, which is the outer peripheral edge of the synthetic resin coating, may be caught by an annular notch on the cylinder side, which makes the operation of aligning the axis of the cylinder and both closing members complicated. Then, the entire outer peripheral edge of the synthetic resin coating is not completely accommodated in the annular notch, and the part of the outer peripheral edge of the synthetic resin coating is assembled with the position being shifted outward from the annular notch. May be completed. In this case, leakage of the refrigerant gas sucked and discharged into the cylinder causes deterioration of the performance of the compressor. Further, when the synthetic resin coating and the end face of the rotor slide, abnormalities occur. There was a drawback that seizure occurred due to wear.

In view of the circumstances described above, the present invention described in claim 1 includes a cylindrical cylinder disposed in a casing, a pair of closing members for closing front and rear openings in the axial direction of the cylinder, and the cylinder. In a rotary compressor including a compression space formed by a pair of closing members, and a rotor accommodated in the compression space and movable in conjunction with a drive shaft,
A recess is formed in a region of the inner wall surface of each closure member facing the compression space, and a synthetic resin coating is embedded in the recess, so that the closure member becomes a surface of the synthetic resin coating and a radially outer side thereof. The original inner wall surface is configured to be the same surface.

  According to the configuration described above, it is possible to easily manage the dimensions of the recess and the synthetic resin coating in the process of manufacturing both the closing members. And since the synthetic resin coating embedded in the concave portion is flush with the inner wall surface, seizure of the synthetic resin coating that becomes the end surface of the rotor and the thrust surface can be prevented, and the manufacturing cost is lower than the conventional one. An inexpensive rotary compressor can be provided.

The longitudinal cross-sectional view which shows one Example of this invention. Sectional drawing of the principal part which follows the II-II line | wire of FIG. The enlarged view of the principal part of FIG. The enlarged view of the principal part of FIG. The horizontal sectional view of the important section showing the 2nd example of the present invention. The longitudinal cross-sectional view of the principal part in 2nd Example shown in FIG. Sectional drawing of the principal part in the other Example of this invention. Sectional drawing of the principal part in the other Example of this invention. The longitudinal cross-sectional view of the principal part which shows the other Example of this invention. The front view of the principal part which shows the other Example of this invention. Sectional drawing which shows the prior art disclosed by patent document 2. FIG. Sectional drawing which shows the prior art disclosed by patent document 3. FIG.

The present invention will be described below with reference to the illustrated embodiments. In FIGS. 1 and 2, reference numeral 1 denotes a rotary compressor 1, which is mainly used for home or commercial air conditioners. 5, 6 and 8 are mainly used for an air conditioner for automobiles.
The rotary compressor 1 is disposed at the upper part in the sealed casing 2 as a drive source and disposed at the lower part in the sealed casing 2 and is rotated by the motor 3 to suck and discharge refrigerant gas. And a compression mechanism 4.
The compression mechanism 4 includes a cylindrical cylinder 5 fitted on the inner surface of the hermetic casing 2 and a cylindrical shape that is accommodated in the cylinder 5 and a part of the outer peripheral surface 6C is always in contact with the inner peripheral surface 5A of the cylinder 5. The rotor 6, the vane 8 that is slidably fitted in the radial guide groove 5 </ b> B of the cylinder 5, and whose tip is always in contact with the outer peripheral surface 6 </ b> C of the rotor 6 by the spring 7, and the axial direction of the cylinder 5 And a pair of upper and lower closing members 11 and 12 for closing the end surfaces 5C and 5D serving as openings.

The pair of closing members 11 and 12 are arranged in a state where the upper and lower end surfaces 5C and 5D of the cylinder 5 are sandwiched from above and below, and these cylinders 5 and both the closing members 11 and 12 have a plurality of positions in the circumferential direction. The fastening bolts 13 are integrally connected while maintaining airtightness. As a result, the space surrounded by the cylinder 5 and the both closing members 11 and 12 is a compression space 14, and the inner wall surfaces 11A and 12A (thrust surfaces) of the both closing members 11 and 12 facing the compression space 14 are The rotor 6 is close to the end faces 6A and 6B. The compression space 14 of the cylinder 5 is partitioned into two adjacent space portions by the vane 8 and the outer peripheral surface 6C of the rotor 6. One space portion serves as the suction chamber 15, and the other space portion serves as the compression chamber. It is 16.
Through holes 11B and 12B are formed in the center of the upper and lower closing members 11 and 12, and the drive shaft 3A of the motor 3 is penetrated through the through holes 11B and 12B of both the closing members 11 and 12 while maintaining airtightness. And also penetrates the rotor 6. The drive shaft 3 </ b> A is rotatably supported by the through holes 11 </ b> B and 12 </ b> B of both the closing members 11 and 12. Further, the drive shaft 3A located in the rotor 6 is a large-diameter eccentric portion 3B in which the shaft center is shifted in the radial direction from the axis of the original drive shaft 3A, and the large-diameter eccentric portion 3B is the rotor 6 It slides in the circumferential direction with the inner peripheral surface of the.
When the drive shaft 3A of the motor 3 is rotated in a predetermined direction, the large-diameter eccentric portion 3B is also rotated, so that the rotor 6 follows the inner peripheral surface 5A of the cylinder 5 in conjunction with the rotation of the large-diameter eccentric portion 3B. To be rotated. At this time, a part of the outer peripheral surface 6C of the rotor 6 is slid while maintaining a contact state with the inner peripheral surface 5A of the cylinder 5, and the tip of the vane 8 biased by the spring 7 is The outer peripheral surface 6C is slid while maintaining a contact state. Since the volumes of the suction chamber 15 and the compression chamber 16 are expanded and contracted by rotating the rotor 6 in this way, the refrigerant gas is sucked into the suction chamber 15 through the suction port 17 and then compressed, and then the compression chamber. 16 is discharged through the discharge port 18 to the outside of the cylinder 5 (outside of the sealed casing 2).
Lubricating oil 21 is stored in the lower part of the hermetic casing 2, and when the rotor 6 is rotated, the rotor 6 passes through an oil passage (not shown) formed in the lower end of the drive shaft 3A. Lubricating oil 21 is supplied to the sliding portion between the inner peripheral surface 6D and the outer peripheral surface 6C. Such a configuration of the rotary compressor 1 is known, for example, from Patent Document 1.

Thus, in this embodiment, by improving the inner wall surfaces 11A and 12A of the closing members 11 and 12 connected to the cylinder 5, both end surfaces 6A and 6B of the rotor 6 and the inner wall surface 11A which is a thrust surface, It is characterized by being configured to suppress seizure of 12A.
That is, as shown in an enlarged view in FIGS. 3 to 4, the inner wall surfaces 11A and 12A of both the closing members 11 and 12 are arranged on the outer peripheral side close to the fastening bolt 13 from the through holes 11B and 12B on the center side. Circular recesses 11C and 12C having a shallow depth are formed over the region. The outer diameters of the recesses 11C and 12C are set to be the same, and the depths of the recesses 11C and 12C are set to the same dimension. Specifically, the depth of the recesses 11C and 12C is set to, for example, 1 μm to 100 μm, and preferably 5 μm to 50 μm.
When the cylinder 5 and the closing members 11, 12 are connected by the plurality of fastening bolts 13, the outer peripheral edges 11 </ b> D, 12 </ b> D of the recesses 11 </ b> C, 12 </ b> C are positioned radially outward from the inner peripheral surface 5 </ b> A of the cylinder 5. Thus, it overlaps with the end faces 5C and 5D of the cylinder 5.

And the synthetic resin coatings 22 and 22 are given to the whole area in the recessed parts 11C and 12C of both the closing members 11 and 12 by the thickness corresponding to the depth of these recessed parts 11C and 12C. Accordingly, the surfaces of the synthetic resin coatings 22 and 22 are flush with the inner wall surfaces 11A and 12A of the original closing members 11 and 12 that are adjacent to the outer sides of the recesses 11C and 12C.
Furthermore, in this embodiment, as shown in FIG. 4, annular grooves 22A having the same depth and width are formed concentrically on the surface of the synthetic resin coating 22 at a predetermined pitch in the radial direction. That is, regular irregularities are formed on the surface of the synthetic resin coating 22 by the adjacent annular grooves 22A and the annular protrusions 22B at the adjacent positions.
The annular protrusion 22B adjacent to each annular groove 22A becomes a substantial thrust surface of the synthetic resin coating 22, and the thrust surface is flush with the original inner wall surfaces 11A and 12A. In the present embodiment, the width of the annular groove 22A is set to 20 μm to 500 μm, preferably 50 μm to 300 μm. The depth of the annular groove 22A (the height of the annular protrusion 22B) is set to 1 to 20 μm, preferably 2 to 10 μm.
The synthetic resin coating 22 is made of a thermosetting synthetic resin to which at least one of graphite, carbon, PTFE, and MoS ₂ is added. In addition, although such a material is used as the synthetic resin coating material, in order to increase the strength of the material, a hard material such as alumina may be further added to the above-described material. Further, the annular groove 22A may be formed not only on the surface of the synthetic resin coating 22, but also on part or the whole of the inner wall surfaces 11A and 12A on the outer periphery in the radial direction of the synthetic resin coating 22.

As described above, in the present embodiment, the recesses 11C and 12C having shallow depths are formed on the inner wall surfaces 11A and 12A of the closing members 11 and 12, and the insides of the recesses 11C and 12C are covered with the synthetic resin coat 22. Filled and covered.
Since it becomes such a structure, in the manufacturing process of the closure members 11 and 12, when forming the said recessed parts 11C and 12C in the closure members 11 and 12, and synthetic resin coatings 22 and 22 to those recessed parts 11C and 12C When embedding, the dimensions such as the dimensions (depth and outer diameter) of the recesses 11C and 12C and the thickness of the synthetic resin coating 22 can be easily performed. In other words, as in the case of Patent Document 3 described above, the synthetic resin coating 22 can be embedded in the recesses 11 </ b> C and 12 </ b> C without performing complicated dimension management regarding the dimensions of the recesses and the thickness of the synthetic resin coating. .

According to such a present Example, when the axial direction dimension of the cylinder 5 and the rotor 6 is set to a required dimension and each of the above-described constituent members is assembled, the end faces 6A and 6B of the rotor 6 and their proximity positions A slight gap α is maintained with the synthetic resin coating 22 (thrust surface) (see FIG. 3). In the compression process when the rotor 6 is rotated, each component has a thermal expansion difference due to the high-temperature and high-pressure refrigerant gas and the sliding heat generation of the sliding portion of the rotor 6. As a result, the gap α at the time of assembly is narrowed, and even when the end surfaces 6A and 6B of the rotor 6 and the synthetic resin coating 22 which is a thrust surface come into contact with each other, a large number of annular grooves 22A as concave portions are formed. Therefore, the lubricating resin retainability of the synthetic resin coating 22 is good, and the conformability between the end faces 6A and 6B and the synthetic resin coating 22 is also good. Therefore, even when the synthetic resin coating 22 that is the thrust surface is in contact with the end faces 6A and 6B of the rotor 6, the annular protrusion 22B at the position adjacent to the annular groove 22A is substantially on the synthetic resin coating 22 side. As a thrust surface, the end surfaces 6A and 6B of the rotor 6 are brought into contact with each other. That is, the sliding area of the thrust surface is smaller than when the entire synthetic resin coating 22 is a flat surface. Therefore, seizure of the end surfaces 6A and 6B of the rotor 6 and the synthetic resin coating 22 can be prevented satisfactorily.
Further, since the synthetic resin coating 22 has high lubricating oil retention by the plurality of annular grooves 22A, it is possible to reduce sliding heat generation from the cooling performance of the lubricating oil. By reducing the sliding heat generation in this way, the difference in thermal expansion of each component can be reduced, and the initial setting gap between the end surfaces 6A and 6B of the rotor 6 and the synthetic resin coating 22 as the thrust surface is narrowed. Can be set. Thereby, the compression leak of the refrigerant gas from the high pressure side to the low pressure side in the compression space 14 can be suppressed, and the compression efficiency can be improved. As a result, the operation efficiency of the rotary compressor 1 can be improved. .
Further, as described above, sliding heat generation can be reduced by retaining the lubricating oil of the synthetic resin coating 22, so heat exchange in the suction chamber 15 on the refrigerant gas suction side (low temperature) can be suppressed, and suction A decrease in volumetric efficiency due to heat being transferred to the chamber 15 can be prevented. Also in this point, the operating efficiency of the rotary compressor 1 can be improved.
Further, when MoS ₂ is added to the synthetic resin coating 22, the retention of the lubricating oil in the synthetic resin coating 22 is further improved, so that seizure can be prevented by sliding heat generation and low friction of MoS _2. it can.
In addition, the rotary compressor 1 is often exposed to a liquid refrigerant by a liquefaction phenomenon of refrigerant gas due to a difference in temperature between day and night. Since the liquid refrigerant has the effect of washing the lubricating oil, if the thrust surface is exposed to the liquid refrigerant, it becomes a dry environment in which the lubricating oil is deficient. Conventionally, in this case, there is no lubricating oil when starting the compressor. The seizure phenomenon of the thrust surface may occur. However, in this embodiment, since the thrust surface is covered with the synthetic resin coating 22, it is possible to prevent seizure of the thrust surface, that is, the portion of the synthetic resin coating 22, even in a dry environment where the lubricating oil is insufficient. Can do.
Furthermore, by adding PTFE to the above-described material as the synthetic resin coating 22, it is possible to improve the sliding characteristics of the thrust surface (synthetic resin coating 22) in the dry environment described above. Even so, higher sliding characteristics can be ensured.
Further, as the synthetic resin coating 22, it is possible to use a hard additive such as graphite for the above-described material, and thereby the rigidity of the annular groove 22A of the synthetic resin coating 22 and the annular protrusion at the adjacent position thereof. Can be improved, and thereby good sliding characteristics can be obtained.
Further, in the case where the synthetic resin coating 22 is not provided as the thrust surface, if foreign matter enters between the end surfaces 6A and 6B of the metal rotor 6 and the inner wall surfaces 11A and 12A of the metal closing members 11 and 12, For this reason, seizure occurs on the end faces 6A and 6B of the rotor 6. However, in this embodiment, the synthetic resin coating 22 exists as a thrust surface, so that the foreign matter is buried in the synthetic resin coating 22. Thus, since the synthetic resin coating 22 has a foreign substance burying property, the seizure of the rotor 6 can be prevented according to the present embodiment also in this respect.

Next, FIG. 5 to FIG. 6 show the main part of the rotary compressor 1 of the second embodiment to which the present invention is applied. This second embodiment is applied to the vane rotary compressor 1. The present invention is applied.
That is, the vane-type rotary compressor 1 includes a cylindrical cylinder 5, a columnar rotor 6 accommodated in the cylinder 5 and rotated by a drive shaft 3 </ b> A of the motor, and a radially outer portion of the rotor 6. The three vanes 8 provided and a pair of closing members 11 and 12 that close the end surfaces 5C and 5D that are the front and rear openings of the cylinder 5 are provided. The cylinder 5 and the closing members 11 and 12 are connected to each other by a plurality of fastening bolts 13 so as to be hermetically sealed, and the compression space 14 in the cylinder 5 is divided into three parts by the outer peripheral surface of the rotor 6 and the three vanes 8. It is divided into working chambers 15.
When the drive shaft 3A arranged coaxially with the rotor 6 is rotated, the rotor 6 is rotated, so that the tips of the three vanes 8 are moved while being in contact with the inner peripheral surface 5A of the cylinder 5. One working chamber 15 is expanded and contracted. Accordingly, the refrigerant gas sucked into the working chamber 15 from the suction port 17 is compressed and then discharged to the outside of the cylinder 5 through the discharge port 18. Such a basic configuration of the second embodiment is not different from that of Patent Document 3 described above, for example.
And also in this 2nd Example, as shown in FIG. 6, the recessed parts 11C and 12C similar to 1st Example mentioned above are formed in both the closure members 11 and 12, And these recessed parts 11C, 12C is provided with a synthetic resin coating 22 as in the first embodiment described above. Further, although not shown in the drawings, a large number of annular grooves are formed on the surface of the synthetic resin coating 22 of the second embodiment as in the first embodiment shown in FIG.
In the second embodiment, members corresponding to those in the first embodiment are given the same member numbers. Even if it is the rotary compressor 1 of 2nd Example comprised in this way, the effect | action and effect similar to the said 1st Example can be acquired.

  Further, in the first embodiment, the case where the present invention is applied to the rotary compressor 1 in which the cylindrical rotor 6 and the flat vane 8 are separated has been described. However, as shown in FIG. The rotary compressor 1 is provided with a rotor 6 having a vane 8 fixed integrally therewith, and the rotor 6 is oscillated within the cylinder 5 by a motor drive shaft 3A and its eccentric large diameter portion 3B. The present invention can also be applied. Since the rotary compressor 1 having such a configuration is known from the above-mentioned Patent Document 2, detailed description thereof is omitted. The configuration shown in FIG. 3 can be adopted as a pair of closing members for closing the cylinder 5 of the rotary compressor 1 shown in FIG. In the embodiment shown in FIG. 7, members corresponding to those in the first embodiment are given the same member numbers.

The second embodiment shown in FIGS. 5 and 6 is a rotary type in which the inner peripheral surface 5A of the cylinder 5 is cylindrical and three vanes 8 are arranged on the outer peripheral surface 6C of the rotor 6. Although the present invention is applied to the compressor 1, as shown in FIG. 8, the present invention is also applied to the rotary compressor 1 having five vanes 8 on the outer peripheral portion of the rotor 6 and the cylinder 5 having an elliptical cross section. The invention can be applied. The configuration shown in FIG. 3 can be applied as a pair of closing members for closing the cylinder 5 of the rotary compressor 1 shown in FIG. 8 and the end face that is the opening in the axial direction thereof. In the embodiment shown in FIG. 8, members corresponding to those in the second embodiment are given the same member numbers.
5 to 8, the embodiment in which the present invention is applied to the rotary compressor 1 having three or five vanes 8 is disclosed. However, the vane type having one or more vanes 8 is disclosed. The present invention can be applied to any rotary compressor 1.

Next, FIG. 9 shows still another embodiment of the present invention. In short, the embodiment shown in FIG. 9 is one in which the present invention is applied to a rotary type compression 101 having the configuration of FIG.
That is, the compression mechanism 104 of the rotary compressor 101 includes an upper closing member 111 fitted in the hermetic casing 102 and a first cylinder 105 whose upper opening is closed by an inner wall surface 111A (lower surface) of the closing member 111. A disc-shaped intermediate closing member 120 in which the lower opening of the first cylinder 105 is closed, a second cylinder 105 ′ in which the upper opening is closed by the lower surface of the intermediate closing member 120, and the second cylinder 105 And a lower closing member 112 that closes the lower opening.
A space surrounded by the first cylinder 105, the closing member 111, and the intermediate closing member 120 is a first compression space 114, in which the first rotor 106 is accommodated. In the first rotor 106, a first large-diameter eccentric portion 103B of the drive shaft 103A of the motor 103 is fitted so as to be slidable in the circumferential direction.
A space surrounded by the intermediate closing member 120, the second cylinder 105 ′ and the lower closing member 112 is a second compression space 114 ′, in which the second rotor 106 ′ is accommodated. . A second large-diameter eccentric portion 103B ′ of the drive shaft 103A is slidably fitted in the second rotor 106 ′.
The upper and lower closing members 111, 112, the intermediate closing member 120, and both cylinders 105, 105 ′ are integrally connected by a plurality of fastening bolts 113. The configuration of such a multistage rotary compressor 101 is well known in, for example, Japanese Patent Application Laid-Open No. 2008-280485, and a detailed description thereof is omitted.
And the structure similar to the said FIG.3 and FIG.4 is employ | adopted also in the location which faces both compression space 114,114 'in the rotary compressor 101 in such a structure. That is, the inner wall surface (lower surface) 111A of the upper closing member 111 and the upper surface 120A (inner wall surface) of the intermediate closing member 120 are provided with the same concave portion as in FIG. 4 and a resin coating filling it. Also, the lower surface 120B (inner wall surface) of the intermediate closing member 120 and the inner wall surface 112A (upper) of the lower closing member 112 are provided with a recess similar to that shown in FIG. 4 and a resin coating filling it. In the embodiment shown in FIG. 9, each member corresponding to FIG. 1 and FIG. As described above, the configuration of the present invention shown in FIGS. 3 to 4 can be applied to both the closing members 111 and 112 and the intermediate closing member 120 in the multistage rotary compressor 1.

In each of the above-described embodiments, a plurality of recesses are formed by providing a plurality of annular grooves 22A on the surface of the synthetic resin coating 22. However, as shown in FIG. By forming vertical and horizontal grid-like projections 22C on the surface of the resin coating 22, regular rectangular recesses 22D may be formed at positions adjacent to the grid-like projections 22C. In this case, each lattice-like protrusion 22C becomes a substantial thrust surface.
Further, the plurality of annular grooves 22A may be formed in concentric circles having different pitches, or may be formed in a spiral groove instead of the annular groove. A large number of annular grooves 22A on the surface of the coating 22 may be omitted, and the entire surface of the synthetic resin coating 22 may be a flat surface.

DESCRIPTION OF SYMBOLS 1 ... Rotary type compressor 2 ... Sealed casing 5 ... Cylinder 6 ... Rotor 11, 12 ... Closure member 11C, 12C ... Recessed part 14 ... Compression space 22 ... Synthetic resin coating

Claims (4)

A cylindrical cylinder disposed in the casing; a pair of closing members for closing front and rear openings in the cylinder; a compression space formed by the cylinder and the pair of closing members; And a rotary compressor including a rotor that is moved in conjunction with a drive shaft,
A recess is formed in a region of the inner wall surface of each closure member facing the compression space, and a synthetic resin coating is embedded in the recess, so that the closure member becomes a surface of the synthetic resin coating and a radially outer side thereof. A rotary compressor characterized in that the original inner wall surface is the same surface.   When the cylinder and the pair of closing members are connected by the fastening means, the outer peripheral edge of the synthetic resin coating and the outer peripheral edge of the recess are located radially outward from the inner peripheral surface of the cylinder and The rotary compressor according to claim 1, wherein the rotary compressor is in contact with an end face in the axial direction.   3. The rotary compressor according to claim 1, wherein a plurality of concentric annular grooves are formed at the same pitch in a radial direction on a surface of the synthetic resin coating.   3. The surface of the synthetic resin coating is formed with lattice-like protrusions, whereby a large number of regular recesses are formed on the surface of the synthetic resin coating. The described rotary compressor.

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