JP2019011701A - Compressor - Google Patents

Abstract

To provide a compressor which is prevented in the exfoliation of a slide layer caused by extreme pressure at an end part of a slide bearing composed of multiple layers.SOLUTION: When using a bush 50 which is constituted of a slide layer 52 including a back metal 51 and PTFE for a slide bearing 14 for supporting a shaft 2, a large load is made to hardly act on an end face of the bush 50 at an internal peripheral side from the shaft 2 even if inserting the bush 50 into an attachment hole 61 of a housing 5 by making an end part of the bush 50 possess a non-contact region 50a non-contacting with the housing 5.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a compressor in which a sliding bearing is used as a bearing that supports a shaft.

  As a shaft bearing of a compressor, for example, as shown in Patent Document 1, a slide bearing is press-fitted into a hole of a housing, and the shaft is rotatably supported on the housing of the compressor via the slide bearing. . In this compressor, a rotor, which is a component of a compression mechanism, is fixed to the shaft, and a reaction force accompanying compression of the working fluid is transmitted to the shaft and supported by a bearing that suspends the shaft.

  Further, as a sliding bearing inserted into the hole of the housing, it is known to use a so-called wound bush in which a sliding member in which a sliding layer containing a solid lubricant is lined is formed in a cylindrical shape on a steel back metal. . For example, in Patent Document 2, a porous sintered layer made of a copper alloy or the like is integrally formed on a back metal made of a rolled steel plate, and a sliding layer made of polytetrafluoroethylene (hereinafter referred to as PTFE) containing a filler is lined. A layer sliding member is shown.

JP 2013-217276 A JP-A-6-93283

  The sliding layer is not only bonded in the radial direction to the back metal via the sintered layer, but is also more stably fixed to the back metal because the sliding layer itself is continuous in an annular shape. On the other hand, since the shaft of the compressor is slightly elastic, in the compressor of Patent Document 1, the radial load from the shaft tends to concentrate on the side close to the rotor among the ends of the sliding bearing. . As described above, since the sliding layer is continuous in an annular shape, it is more stably fixed to the back metal. However, since one side is open at the end of the sliding bearing, When the fixing to the back metal is relatively weak and the radial load of the shaft is concentrated on the end of the sliding bearing, there is a concern that the sliding layer may be peeled off from the back metal due to the circumferential frictional force received from the rotating shaft.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a compressor with improved reliability by suppressing the peeling of the sliding layer on the end face of the sliding bearing.

  In order to achieve the above object, a compressor according to claim 1 includes a housing, a sliding bearing mounted in a mounting hole formed in the housing, and a shaft rotatably supported via the sliding bearing. And a compression mechanism for converting the rotational movement of the shaft into a compressive action of the working fluid, and the sliding bearing is composed of a back metal and a sliding layer lined on the inner peripheral side of the back metal. In addition, the slide bearing further has a non-contact portion that does not contact the mounting hole at the end portion on the compression mechanism side. The non-contact part refers to a part protruding from, for example, an entrance of a hole formed in the housing (a part where the back metal starts to contact the housing when a chamfered part is formed in the hole).

  As a result, even if a radial load is applied from the shaft, the sliding bearing has a non-contact portion that does not contact the mounting hole, so that the end portion on the compression mechanism side is easily deformed in a direction to escape from the shaft. The sliding load made of PTFE or the like can be prevented from being displaced from the interface with the back metal and peeling off.

  The compressor according to claim 2, wherein the compression mechanism is a rotor fixed to the shaft, a vane groove formed radially outward from an outer peripheral surface of the rotor, and can move forward and backward in the vane groove. A vane-type compression mechanism having a vane housed in a cylinder, a cylinder forming portion that houses the rotor, and a side block forming portion that closes both axial ends of the cylinder forming portion. The non-contact portion is provided in at least one of the sliding bearings.

  In the vane compressor, the load applied to the sliding bearing is mainly a radial load due to the pressure in the compression chamber on the outer periphery of the rotor, and the direction in which the high load acts is determined. Thus, a non-contact portion that does not contact the housing is formed at the end of the bush of the sliding bearing to reduce the load applied to the end, thereby preventing the sliding layer from peeling off from the end surface on the inner diameter side of the bush. It becomes more effective as a response.

  The non-contact part of the sliding bearing of the compressor according to claim 3 has an oil introduction part that guides oil between the sliding layer and the shaft at a part that does not receive a load from the shaft. It is a feature.

  Since this oil introduction part is not provided where the load from the shaft acts, lubrication oil is supplied between the sliding layer of the sliding bearing and the shaft while ensuring the function of supporting the shaft rotatably. It becomes possible to do.

  The non-contact portion of the sliding bearing of the compressor according to claim 4 is characterized in that an oil introduction portion that guides oil between the sliding layer and the shaft is provided at an upper portion in a vertical direction.

  As a result, the lubricating oil that has flowed from the upper side to the sliding bearing on the wall surface of the housing is taken in between the sliding layer and the shaft through the oil introducing portion formed in the upper part of the sliding bearing.

  The groove part for supplying oil to the rear end of the shaft is formed on the inner peripheral surface of the mounting hole of the housing of the compressor according to claim 5 at a location where the load from the shaft is not received. It is characterized by. The part not receiving a high load from the shaft on the inner peripheral surface of the mounting hole of the housing is, for example, a part located above the sliding bearing.

  As a result, the lubricating oil that has flowed from the upper side to the mounting hole of the housing through the wall surface of the housing passes through the groove formed on the inner peripheral surface of the mounting hole of the housing and is sent to the rear end rather than the sliding bearing of the shaft.

  As described above, according to the present invention, even if a high load is applied to the sliding bearing from the shaft, the end of the sliding bearing is provided by having a non-contact portion that is not in contact with the housing at the compression mechanism side end of the back metal. The portion is easily deformed in the direction of escaping from the shaft, and the portion that receives the load from the shaft is no longer on the end portion side of the slide bearing. For this reason, it is possible to reduce the load concentrated in the end by dispersing the radial load from the shaft, and it is possible to prevent the sliding layer made of PTFE or the like from deviating from the interface with the back metal and peeling off. .

It is sectional drawing of the vane type compressor shown as an example of the compressor to which this invention is applied. It is sectional drawing of the vane type compressor which removed the rotor and the shaft, and showed the state in which the slide bearing was inserted in the hole of the housing. FIG. 3A is an enlarged view of a main part of the vane compressor shown in FIG. 1, and FIG. 3B is a further enlarged view of FIG. It is a perspective view which shows an example of the sliding bearing of this invention.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
1 to 3, a vane compressor 1 suitable for a refrigeration cycle using a refrigerant as a working fluid is shown as an example of a compressor to which the present invention is applied. In FIG. 1, the left side is the front side and the right side is the rear side.

  The vane compressor 1 includes a shaft 2, a rotor 3 that is fixed to the shaft 2 and rotates as the shaft 2 rotates, a vane 4 that is removably attached to a vane groove 41 of the rotor 3, and a shaft 2. And a housing 5 that accommodates the rotor 3 and the vane 4.

  The housing 5 is configured by combining two members of the first housing member 10 and the second housing member 20. The first housing member 10 houses the rotor 3 and closes the cylinder forming portion 12 having the cam surface 11 formed on the inner peripheral surface and one end side (rear side) in the axial direction of the cylinder forming portion 12. The first side block forming portion 13 is formed integrally with the first side block forming portion 13. In this embodiment, the inner peripheral surface (cam surface 11) of the cylinder forming portion 12 is formed into a perfect circle in cross section, and the axial length is substantially equal to the axial length of the rotor 3 described later. .

  The second housing member 20 includes a second side block forming portion 21 that is in contact with an end face on the other end side (front side) in the axial direction of the cylinder forming portion 12 and closes the other end side. A shell forming portion 22 formed integrally with the side block forming portion 21 and extending in the axial direction of the shaft 2 so as to surround the outer peripheral surfaces of the cylinder forming portion 12 and the first side block forming portion 13. And is configured.

  The first housing member 10 and the second housing member 20 are fastened in the axial direction via a coupling tool such as a bolt (not shown). A seal member 6 such as an O-ring is interposed between the first side block forming portion 13 and the shell forming portion 22 so as to be airtightly sealed.

  Further, the second housing member 20 is integrally formed with a boss portion 23 extending from the second side block forming portion 21 to the front side. A pulley (not shown) that applies rotational force to the shaft 2 described below is rotatably mounted on the boss portion 23 so that rotational power is transmitted from the pulley to the shaft 2 via an electromagnetic clutch (not shown). It has become.

  The shaft 2 is rotatably supported by the first side block forming portion 13 and the second side block forming portion 21 via a slide bearing 14 described in detail later. The shaft 2 protrudes into the boss portion 23 of the second housing member 20 and is hermetically sealed by a seal member 25 provided between the shaft 2 and the working fluid (refrigerant gas) is bossed. This prevents leakage from the opening of the portion 23 to the outside.

  The rotor 3 has a cylindrical shape with a perfect cross section. The shaft 2 is inserted into an insertion hole 3a provided at the center of the rotor 3 and is fixed to the shaft 2 in a state where the axes are aligned. Yes. In this embodiment, the axial center of the cylinder forming portion 12 and the axial center of the rotor 3 (shaft 2) are such that the outer peripheral surface of the rotor 3 and the inner peripheral surface (cam surface 11) of the cylinder forming portion 12 are in the circumferential direction. They are shifted so as to be close to each other (for example, they are shifted by a half of the difference between the inner diameter of the cylinder forming portion 12 and the outer diameter of the rotor 3). In the space closed by the cylinder forming portion 12, the first side block forming portion 13, and the second side block forming portion 21, the inner peripheral surface (cam surface 11) of the cylinder forming portion 12 and the rotor 3 A compression space 30 is defined between the outer peripheral surface and the outer peripheral surface.

  The second housing member 20 has a suction port for sucking working fluid (refrigerant gas) from the outside and a discharge port for discharging the working fluid (refrigerant gas) to the outside. The cylinder forming portion 12 of the first housing member 10 is configured so that the rotor 3 has a portion (hereinafter referred to as a radial seal portion 40) where the outer peripheral surface of the rotor 3 is close to the inner peripheral surface (cam surface 11) of the cylinder forming portion 12. A suction port 15 communicating with the suction port is formed in the vicinity of the front side in the rotation direction, and a discharge port 16 communicating with the discharge port is formed near the rear side in the rotation direction of the rotor 3. In addition, in FIG. 2, the code | symbol 10a has shown the screw hole which screws together the coupling tool mentioned above.

  The discharge port 16 has a counterbore 16a that is recessed in a curved shape along the circumferential direction at the opening end with the inner peripheral surface (cam surface 11) of the cylinder forming portion 12, and the compressed gas is in this seat. It is discharged through the bore 16a. A discharge chamber 32 is formed between the cylinder forming portion 12 of the first housing member 10 and the second housing member 20 shell forming portion 22 over a predetermined range in the circumferential direction. The discharge port 16 opens into the discharge chamber 32 and is closed by a discharge valve 33 provided in the discharge chamber 32 so as to be opened and closed. In FIG. 1, reference numeral 34 indicates a retainer that restricts the movement of the discharge valve 33.

  A discharge space 35 to which the discharge port is connected is formed between the first side block forming portion 13 of the first housing member 10 and the shell forming portion 22 of the second housing member 20. The discharge chamber 32 communicates with the discharge space 35 via an oil separator (not shown). The discharge chamber 32 and the discharge space 35 constitute a high-pressure space that accommodates the fluid discharged from the discharge port 16.

  Further, a working fluid (refrigerant) is provided between the lower portion of the first side block forming portion 13 of the first housing member 10 and the lower portion of the shell forming portion 22 of the second housing member 20 by an oil separator (not shown). An oil reservoir chamber 18 is provided for collecting the oil separated from the oil reservoir.

  A plurality of vane grooves 41 are formed on the outer peripheral surface of the rotor 3, and the vanes 4 are slidably inserted into the respective vane grooves 41. The vane groove 41 is opened not only on the outer peripheral surface of the rotor 3 but also on the end surface facing the first side block forming portion 13 and the second side block forming portion 21, and a back pressure chamber 41 a is formed at the bottom portion. Has been. A plurality of (for example, two) vane grooves 41 are formed at equal intervals in the circumferential direction.

  The vane 4 is formed so that the width along the axial direction of the shaft 2 is equal to the axial length of the rotor 3, and the length in the insertion direction (sliding direction) into the vane groove 41 is the same as that of the vane groove 41. It is formed approximately equal to the length in the direction. The vane 4 is protruded from the vane groove 41 due to the back pressure supplied to the back pressure chamber 41 a of the vane groove 41, and the tip portion can come into contact with the inner peripheral surface (cam surface 11) of the cylinder forming portion 12. ing.

  Therefore, the compression space 30 is partitioned into a plurality of compression chambers 31 by the vanes 4 slidably inserted into the vane grooves 41, and the volume of each compression chamber 31 changes as the rotor 3 rotates. ing.

  The first side block forming portion 13 has an end surface facing the axial end surface of the rotor 3, and a first recess 13 a that can communicate with the back pressure chamber 41 a provided at the bottom of the vane groove 41, and a second A recess 13b is formed. The first side block forming portion 13 has a first communication passage 17 that communicates the first recess 13a with the oil reservoir chamber 18 and supplies oil from the oil reservoir chamber 18 to the first recess 13a. Is formed. The first side block forming portion 13 is formed with a second communication passage 19 that communicates the second recess 13b and the high-pressure space.

  According to the above configuration, when the rotational power from the power source (not shown) is transmitted to the shaft 2 and the rotor 3 rotates, the working fluid (refrigerant) flowing from the suction port is sucked into the compression space 30 via the suction port 15. Is done. Since the volume of the compression chamber 31 partitioned by the vanes 4 in the compression space 30 changes as the rotor 3 rotates, the working fluid (refrigerant) confined between the vanes 4 is compressed and discharged from the discharge port 16 to the discharge valve. It is discharged into the discharge chamber 32 through 33. The working fluid (refrigerant) discharged into the discharge chamber 32 moves in the circumferential direction along the outer peripheral surface of the cylinder forming portion 12 (inner peripheral surface of the shell forming portion 22), and is formed in the first side block forming portion 13. It is introduced into an oil separation chamber of an oil separator (not shown). Thereafter, the working fluid is separated from the oil in the course of swirling in the oil separation chamber of the oil separator, and discharged from the discharge port to the external circuit.

  In this embodiment, since the center of the cam surface 11 of the cylinder forming portion 12 is shifted downward with respect to the rotation center of the rotor 3, the pressure in the compression chamber 31 increases as it approaches the upper side. For this reason, the compression reaction force received by the rotor 3 is always downward, and this load is supported by the sliding bearing 14 via the shaft.

  Incidentally, the sliding bearing 14 located on the front side and the sliding bearing 14 located on the rear side of the vane compressor 1 are formed of an annular bush 50, as shown in FIG. A multi-layered structure is formed with a sliding layer 52 containing PTFE formed on the inner diameter side of the back metal 51. Specifically, a copper-based porous sintered layer is integrally formed on the back metal 51, and the porous sintered layer is impregnated and fired with a mixture of a filler and PTFE, thereby forming a sliding layer as a lubricating layer. 52 is lined. The thickness of the sliding layer 52 is, for example, 30 microns.

  As shown in FIG. 3, the bush 50 as the rear-side sliding bearing 14 is mounted in a mounting hole 61 formed in the first side block forming portion 13. In this embodiment, the end of the bush 50 is provided so as to protrude from the end surface of the recess 13a of the first side block forming portion 13 to the rotor side.

  Thereby, the part which protruded from the end surface of the recessed part 13a of the 1st side block formation part 13 of the bush 50 of the rear side sliding bearing 14 turns into the non-contact part 50a which is not contact | abutting to the mounting hole 61. FIG. Therefore, even if a high load is applied from the shaft 2 to the end of the bush 50 closer to the rotor due to the elastic deformation of the shaft 2 to which the rotor 3 is fixed due to the compression reaction force acting on the rotor 3 due to the rotation of the shaft 2. The end of 50 is deformed in a direction in which the non-contact portion 50a escapes from the shaft 2, whereby the load at the end of the bush is dispersed. Further, the portion where the load is most applied from the shaft 2 is not the end portion of the bush 50. Therefore, it is possible to reduce the load applied from the shaft 2 to the end surface on the inner diameter side at the end portion of the bush 50, and to prevent the sliding layer 52 from being displaced from the interface with the back metal 51 near the end portion. Become.

  In addition, the non-contact part 50a does not necessarily need to be annular, and for example, only the part that is most heavily loaded from the shaft 2 may protrude. Further, the non-contact part 50 a can be formed not only by projecting the bush 50 from the mounting hole 61 but also by forming a chamfer on the outer peripheral surface near the end of the back metal 51 or the mounting hole 61.

  Furthermore, as shown in FIGS. 3 and 4, the non-contact part 50 a of the bush 50 is cut out at the upper part in the vertical direction of the bush 50 to form an oil introduction part 53. Thus, the lubricating oil that has flowed from above through the wall surface of the recess 13a of the first housing member 10 is not disturbed by the non-contact portion 50a protruding from the end surface of the recess 13a, and the flow of FIG. As indicated by the arrow), the oil is introduced between the inner periphery of the bush 50 and the shaft 2 after passing through the oil introduction portion 53 formed in the bush 50 and reaching the upper portion of the peripheral surface of the shaft 2. Therefore, more lubricating oil can be supplied between the bush 50 and the shaft 2.

  As shown in FIGS. 3 and 4, the mounting hole 61 of the first side block forming portion 13 is provided with a groove portion 63 at a location above the bush 51. The groove 63 extends to the rear side of the sliding bearing 14 along the axial direction of the shaft 2. As a result, as shown by the arrow in FIG. 3B, the lubricating oil that has flowed to above the hole 61 of the first housing member 10 passes through the groove 63 and is behind the sliding bearing 14 of the shaft 2. It is possible to send to the end side. Therefore, the rear end of the shaft 2 can be lubricated better than the slide bearing 14 and the pressure before and after the slide bearing 14 can be equalized.

  In the above description and FIG. 3, the oil introduction portion 53 and the groove portion 63 are shown in the same cross-sectional view above the bush 50, but the oil introduction portion 53 and the groove portion 63 are configured independently of each other. Alternatively, as long as the load is not applied from the shaft 2, it may be arranged in another cross-sectional part.

  Even when the bush 50 used for the front side slide bearing 14 is inserted into the mounting hole of the housing 5 similarly to the bush 50 used for the rear side slide bearing 14 shown in FIG. You may make it have the non-contact site | part 50a which is not contact | abutting (the housing 5 does not exist in the outer diameter side).

  Moreover, although the vane type compressor 1 in which the inner peripheral surface of the cylinder forming part 12 is a perfect circle has been described as a compressor to which the present invention is applied, the vane type compressor in which the inner peripheral surface of the cylinder forming part 12 is an elliptical shape. 1 can also be applied.

1 vane type compressor 2 shaft 3 rotor 4 vane 41 vane groove 5 housing 10 first housing member 12 cylinder forming portion 13 first side block forming portion 20 second housing member 21 second side block forming portion 14 Slide bearing 50 Bush 50a Non-contact part 51 Back metal 52 Sliding layer 53 Oil introduction part 61 Mounting hole 63 Groove part

Claims (5)

A housing, a sliding bearing mounted in a mounting hole formed in the housing, a shaft rotatably supported through the sliding bearing, and a compression mechanism for converting the rotational movement of the shaft into a compressing action of a working fluid A compressor comprising:
The sliding bearing is composed of a back metal and a sliding layer lined on the inner peripheral side of the back metal.
Furthermore, the slide bearing has a non-contact portion that does not contact the mounting hole at the compression mechanism side end. The compression mechanism includes a rotor fixed to the shaft, a vane groove formed radially inward from an outer peripheral surface of the rotor, a vane accommodated in the vane groove so as to be movable forward and backward, and the rotor. A vane-type compression mechanism having a cylinder forming portion to be accommodated and a side block forming portion that closes both axial ends of the cylinder forming portion,
The compressor according to claim 1, wherein the sliding bearing is provided in the side block forming portion that forms the housing, and the non-contact portion is provided in at least one of the sliding bearings.   The said non-contact site | part of the said slide bearing has an oil introduction part which guide | induces oil between the said sliding layer and the said shaft in the location which does not receive the load from the said shaft. Compressor.   The said non-contact site | part of the said sliding bearing has an oil introduction part which guides oil between the said sliding layer and the said shaft in the upper part of the perpendicular direction, The Claim 1 or Claim 2 characterized by the above-mentioned. Compressor.   The groove part for supplying oil to the rear end of the shaft is formed in the inner peripheral surface of the mounting hole of the housing at a location not receiving a load from the shaft. The compressor according to claim 2 or claim 3.

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