JP4304544B2 - Refrigerant suction structure in piston type compressor - Google Patents

Description

  The present invention relates to a refrigerant suction structure in a piston compressor in which pistons are accommodated in a plurality of cylinder bores arranged around a rotation shaft, and the piston is interlocked with a rotation of the rotation shaft via a cam body. More specifically, refrigerant suction in a piston type compressor having a rotary valve that is integrated with the rotating shaft and has an introduction passage for introducing refrigerant into a compression chamber defined in the cylinder bore by the piston. Concerning structure.

  2. Description of the Related Art Conventionally, piston type compressors that employ a rotary valve to introduce refrigerant into a cylinder bore are known. A variable capacity swash plate compressor in which a rotary valve separate from the rotary shaft is housed in a valve housing chamber is known (for example, see Patent Document 1). There is also known a fixed displacement swash plate compressor using a double-headed piston in which the rotary shaft itself is a rotary valve (see, for example, Patent Document 2).

The configuration in which the suction port for introducing the refrigerant into the cylinder bore is opened and closed by the rotary valve improves the volume efficiency compared to the structure in which the suction port for introducing the refrigerant into the cylinder bore is opened and closed by a flexible deformable intake valve. enable.
Japanese Patent Laid-Open No. 5-113174 (page 4, FIG. 1) JP-A-7-63165 (page 4, FIG. 1)

  However, in any of the compressors of the above-mentioned patent documents, the refrigerant in the cylinder bore in the discharge stroke is likely to leak out of the cylinder bore along the outer peripheral surface of the rotary valve from the suction passage communicating with the cylinder bore. That is, in the compressor of Patent Document 1, it is required to minimize the clearance between the inner peripheral surface of the valve storage chamber and the outer peripheral surface of the rotary valve in order to prevent refrigerant leakage. very difficult. The compressor of Patent Document 2 also has a similar problem regarding the clearance between the inner peripheral surface of the through hole penetrating the cylinder block and the outer peripheral surface of the rotary valve. Such refrigerant leakage reduces the volumetric efficiency of the compressor.

  An object of this invention is to improve the volumetric efficiency in the piston type compressor using a rotary valve.

For this purpose, the present invention relates to refrigerant suction in a piston-type compressor in which pistons are housed in a plurality of cylinder bores arranged around a rotating shaft in a cylinder block , and the piston is interlocked with a rotation of the rotating shaft via a cam body. Intended for structure. Further, the present invention provides a refrigerant in a piston-type compressor having a rotary valve that is integrated with the rotating shaft and has an introduction passage for introducing the refrigerant into a compression chamber defined by the piston in the cylinder bore. Inhalation structure is targeted.

  The invention of claim 1 further includes a suction passage that communicates with the cylinder bore and intermittently communicates with the introduction passage as the rotary valve rotates. Further, the invention of claim 1 transmits a compression reaction force against the piston in the cylinder bore in the discharge stroke to the rotary valve, and moves toward the inlet of the suction passage communicating with the cylinder bore in the discharge stroke. A compression reaction force transmitting means for urging the valve is provided.

  The piston in the cylinder bore in the discharge stroke receives a compression reaction force, and this compression reaction force is transmitted to the rotating shaft through the piston and the cam body. The compression reaction force transmitted to the rotating shaft urges the rotary valve toward the cylinder bore in the discharge stroke. The rotary valve urged toward the cylinder bore in the discharge stroke is urged toward the inlet of the suction passage communicating with the cylinder bore in the discharge stroke. The configuration in which the rotary valve is urged toward the inlet of the suction passage communicating with the cylinder bore in the discharge stroke contributes to prevention of refrigerant leakage from the suction passage communicating with the cylinder bore in the discharge stroke.

Further, in the invention of claim 1, wherein the cylinder block, that has a shaft hole for rotatably accommodating the rotary valve. The outlet of the introduction passage is provided on the outer peripheral surface of the rotary valve, and the inlet of the suction passage is provided on the inner peripheral surface of the shaft hole . And the radial bearing means which supports the said rotating shaft via the said rotary valve is comprised by the outer peripheral surface of the said rotary valve being directly supported by the said inner peripheral surface of the said shaft hole . Furthermore, the radial bearing means is the only radial bearing means about portions of said rotary shaft in said rotary valve side from the cam body.

The portion of the rotary shaft on the rotary valve side from the cam body is supported only by radial bearing means consisting of the inner peripheral surface of the shaft hole and the outer peripheral surface of the rotary valve. Such a support structure enhances the refrigerant leakage prevention effect by urging the rotary valve toward the inlet of the suction passage.
Furthermore, in the invention of claim 1, the piston is a double-headed piston, a pair of rotary valves corresponding to a pair of front and rear cylinder bores that house the double-headed piston rotate integrally with the rotating shaft, and the cam body is The position in the axial direction of the rotary shaft is regulated by being sandwiched between a pair of front and rear thrust bearing means, and at least one of the pair of thrust bearing means constitutes a part of the compression reaction force transmission means, and the compression reaction force Thrust bearing means forming part of the force transmission means abuts against an annular ridge formed on the end face of the cylinder block and an annular ridge formed on the end face of the cam body, and the protrusion of the cam body The diameter of the stripe is made larger than the diameter of the protrusion of the cylinder block.
The thrust bearing means provided with the thrust load absorbing function allows the rotation shaft to be displaced so as to cause the rotary valve to be biased toward the inlet of the suction passage.

According to a second aspect of the present invention, in the first aspect, a seal peripheral surface having a smaller diameter than other portions is provided on the end portion side of the shaft hole that supports the rotating shaft.
The configuration in which the seal peripheral surface having a smaller diameter than the other part is provided in the shaft hole contributes to making the rotation shaft easy to tilt.

  In the present invention, the rotary valve is urged toward the inlet of the suction passage communicating with the cylinder bore in the discharge stroke by the compression reaction force on the piston in the cylinder bore in the discharge stroke. Thereby, the outstanding effect that the volumetric efficiency in the piston type compressor using a rotary valve can be improved is produced.

  Hereinafter, a first embodiment in which the refrigerant suction structure of the present invention is embodied in a fixed capacity compressor provided with a double-headed piston will be described with reference to FIGS.

  As shown in FIG. 1, a front housing 13 and a rear housing 14 are joined to a pair of joined cylinder blocks 11 and 12. A discharge chamber 131 is formed in the front housing 13. A discharge chamber 141 and a suction chamber 142 are formed in the rear housing 14.

  A valve plate 15, a valve forming plate 16 and a retainer forming plate 17 are interposed between the cylinder block 11 and the front housing 13. A valve plate 18, a valve forming plate 19, and a retainer forming plate 20 are interposed between the cylinder block 12 and the rear housing 14. Discharge ports 151 and 181 are formed on the valve plates 15 and 18, and discharge valves 161 and 191 are formed on the valve forming plates 16 and 19. The discharge valves 161 and 191 open and close the discharge ports 151 and 181. Retainers 171 and 201 are formed on the retainer forming plates 17 and 20. The retainers 171 and 201 regulate the opening degree of the discharge valves 161 and 191.

  A rotating shaft 21 is rotatably supported on the cylinder blocks 11 and 12. The rotary shaft 21 is inserted through shaft holes 112 and 122 that are provided through the cylinder blocks 11 and 12. The rotary shaft 21 is directly supported by the cylinder blocks 11 and 12 through the shaft holes 112 and 122.

  A shaft seal member 22 is interposed between the front housing 13 and the rotating shaft 21. A swash plate 23 (cam body) made of aluminum (including an aluminum alloy) is fixed to the rotating shaft 21. The swash plate 23 is accommodated in a swash plate chamber 24 between the cylinder blocks 11 and 12. The swash plate 23 is a type in which an angle (swash plate inclination angle) formed between the plate-like portion 235 that is in sliding contact with the shoes 301 and 302 and a plane perpendicular to the axis 211 of the rotation shaft 21 is constant. A thrust bearing 25 is interposed between the end face of the cylinder block 11 and the annular base 231 of the swash plate 23.

  A thrust bearing 26 is interposed between the end face of the cylinder block 12 and the base 231 of the swash plate 23. The rotary shaft 21 is positioned in the direction of the axis 211 by being sandwiched between a pair of front and rear thrust bearings (thrust bearing means) 25 and 26.

  As shown in FIG. 4, the thrust bearing 25 includes a pair of races 251 and 252 and a plurality of rollers 253. An annular protrusion 111 is formed on the end surface of the cylinder block 11. The tip of the ridge 111 is in contact with the race 251 of the thrust bearing 25. The race 252 of the thrust bearing 25 is joined to the end surface 232 of the base 231 of the swash plate 23. When the thrust bearing 25 is viewed in the direction of the axis 211 of the rotary shaft 21, the joining range between the ridge 111 and the race 251 and the joining range between the end surface 232 and the race 252 overlap with each other. Therefore, the races 251 and 252 are not bent and deformed by the thrust load. That is, the thrust bearing 25 is not provided with a thrust load absorbing function for absorbing the thrust load.

  As shown in FIG. 5, the thrust bearing 26 includes a pair of races 261 and 262 and a plurality of rollers 263. An annular protrusion 121 is formed on the end surface of the cylinder block 12. The protrusion 121 is in contact with the race 261 of the thrust bearing 26. An annular ridge 234 is formed on the end surface 233 of the base 231 of the swash plate 23. The protrusion 234 is in contact with the race 262 of the thrust bearing 26. The diameter of the ridge 234 is larger than the diameter of the ridge 121. When the thrust bearing 26 is viewed in the direction of the axis 211 of the rotary shaft 21, the joining range between the ridge 121 and the race 261 and the joining range between the ridge 234 and the race 262 do not overlap. Accordingly, the races 261 and 262 can be bent and deformed by a thrust load. That is, the thrust bearing 26 is provided with a thrust load absorbing function for absorbing a thrust load.

  As shown in FIG. 2A, the cylinder block 11 is formed with a plurality of cylinder bores 27, 27 </ b> A arranged around the rotation shaft 21. As shown in FIG. 3A, the cylinder block 12 is formed with a plurality of cylinder bores 28, 28 </ b> A, 28 </ b> B arranged around the rotation shaft 21. Double-headed pistons 29 and 29A are accommodated in the cylinder bores 27, 28, and 28B and the cylinder bores 27A and 28A that are paired in the front-rear direction (the front housing 13 side is the front side and the rear housing 14 side is the rear side).

  As shown in FIG. 1, the rotational movement of the swash plate 23 that rotates integrally with the rotary shaft 21 is transmitted to the double-headed pistons 29 and 29A via the shoes 301 and 302, and the double-headed pistons 29 and 29A are in the cylinder bores 27 and 27A. , 28, 28A, and 28B are reciprocated back and forth. The double-headed pistons 29 and 29A partition the compression chambers 271 and 281 in the cylinder bores 27, 27A, 28, 28A, and 28B.

  Seal peripheral surfaces 113 and 123 are formed on the inner peripheral surfaces of the shaft holes 112 and 122 through which the rotary shaft 21 passes. The diameters of the seal peripheral surfaces 113 and 123 are smaller than the diameters of the other inner peripheral surfaces of the shaft holes 112 and 122, and the rotary shaft 21 is driven by the cylinder blocks 11 and 12 via the seal peripheral surfaces 113 and 123. Directly supported.

  A passage 212 is formed in the rotating shaft 21. The starting end of the passage 212 is on the inner end surface of the rotary shaft 21 and opens to the suction chamber 142 in the rear housing 14. Introducing passages 31 and 32 are formed in the rotary shaft 21 so as to communicate with the passage 212.

  As shown in FIGS. 2A, 2 </ b> B, and 4, suction passages 33 and 33 </ b> A are formed in the cylinder block 11 so as to communicate the cylinder bores 27 and 27 </ b> A and the shaft hole 112. The inlets 331 of the suction passages 33 and 33 </ b> A are opened on the seal peripheral surface 113. As shown in FIGS. 3A, 3 </ b> B, and 5, suction passages 34, 34 </ b> A are formed in the cylinder block 12 so as to communicate the cylinder bores 28, 28 </ b> A, 28 </ b> B and the shaft hole 122. The inlets 341 of the suction passages 34, 34 </ b> A are opened on the seal peripheral surface 123. As the rotary shaft 21 rotates, the outlets 311 and 321 of the introduction passages 31 and 32 intermittently communicate with the inlets 331 and 341 of the suction passages 33, 33A, 34, and 34A.

  When the cylinder bores 27 and 27A are in the suction stroke state (that is, the stroke in which the double-headed pistons 29 and 29A move from the left side to the right side in FIG. 1), the outlet 311 and the inlet 331 of the suction passages 33 and 33A communicate with each other. When the cylinder bores 27 and 27A are in the suction stroke state, the refrigerant in the passage 212 of the rotating shaft 21 is sucked into the compression chambers 271 of the cylinder bores 27 and 27A via the introduction passage 31 and the suction passages 33 and 33A.

  When the cylinder bores 27, 27A are in the discharge stroke state (ie, the stroke in which the double-headed pistons 29, 29A move from the right side to the left side in FIG. 1), the communication between the outlet 311 and the inlet 331 of the suction passages 33, 33A is blocked. The When the cylinder bores 27 and 27 </ b> A are in the discharge stroke state, the refrigerant in the compression chamber 271 is discharged from the discharge port 151 to the discharge chamber 131 by pushing the discharge valve 161 away. The refrigerant discharged into the discharge chamber 131 flows out to an external refrigerant circuit (not shown).

  When the cylinder bores 28, 28A, 28B are in the suction stroke state (ie, the stroke in which the double-headed pistons 29, 29A move from the right side to the left side in FIG. 1), the outlet 321 and the inlet 341 of the suction passages 34, 34A communicate with each other. . When the cylinder bores 28, 28A, 28B are in the suction stroke state, the refrigerant in the passage 212 of the rotating shaft 21 is sucked into the compression chambers 281 of the cylinder bores 28, 28A, 28B via the introduction passage 32 and the suction passages 34, 34A. Is done.

  When the cylinder bores 28, 28A, 28B are in the discharge stroke state (ie, the stroke in which the double-headed pistons 29, 29A move from the left side to the right side in FIG. 1), the communication between the outlet 321 and the inlet 341 of the suction passages 34, 34A is established. Blocked. When the cylinder bores 28, 28 </ b> A, 28 </ b> B are in the discharge stroke state, the refrigerant in the compression chamber 281 pushes the discharge valve 191 away from the discharge port 181 and is discharged into the discharge chamber 141. The refrigerant discharged into the discharge chamber 141 flows out to the external refrigerant circuit. The refrigerant that has flowed into the external refrigerant circuit returns to the suction chamber 142.

  As shown in FIGS. 4 and 5, the portion of the rotary shaft 21 surrounded by the seal peripheral surfaces 113 and 123 becomes rotary valves 35 and 36 integrally formed with the rotary shaft 21. The outer peripheral surfaces 351 and 361 of the rotary valves 35 and 36 surrounded by the seal peripheral surfaces 113 and 123 correspond to the seal peripheral surfaces 113 and 123. The seal peripheral surface 113 is an inner peripheral surface of a valve storage chamber 37 (shown in FIG. 4) that stores the rotary valve 35. The seal peripheral surface 123 is an inner peripheral surface of a valve storage chamber 38 (shown in FIG. 5) that stores the rotary valve 36.

The following effects can be obtained in the first embodiment.
(1-1) It is assumed that the cylinder bore 27A shown in FIG. 1 is in a discharge stroke state. In this case, the lower cylinder bore 28B shown in FIG. 3 is also in the discharge stroke state. The double-headed piston 29A in the cylinder bore 27A in the state of the discharge stroke receives a compression reaction force when the refrigerant in the cylinder bore 27A is discharged into the discharge chamber 131 while being compressed. This compression reaction force is transmitted to the rotary shaft 21 via the double-headed piston 29A, the shoe 301 and the swash plate 23.

  The compression reaction force transmitted to the swash plate 23 via the double-headed piston 29A acts on the swash plate 23 as a force indicated by an arrow F1 in FIG. The compression reaction force transmitted to the swash plate 23 via the double-headed piston 29 in the cylinder bore 28B acts on the swash plate 23 as a similar force F2 (indicated by an arrow F2 in FIG. 1). These forces F1 and F2 tend to tilt the rotary shaft 21 integrated with the swash plate 23 around the center of the diameter of the swash plate 23. The rotary shaft 21 is supported by a bearing so as to be able to contact with and separate from the inner peripheral surfaces of the shaft holes 112 and 122, and the displacement of the rotary shaft 21 with respect to the inner peripheral surfaces of the shaft holes 112 and 122 is transmitted to the rotary valves 35 and 36. Is done.

  That is, the compression reaction force transmitted to the rotary shaft 21 via the double-headed pistons 29A and 29 in the cylinder bores 27A and 28B in the discharge stroke state is attached to the rotary valve 35 toward the cylinder bore 27A in the discharge stroke state. To force. Similarly, the rotary valve 36 is also urged toward the cylinder bore 28B by the compression reaction force.

  The shoes 301, 302, the swash plate 23, and the rotary shaft 21 are compression reaction force transmitting means for urging the rotary valves 35, 36 by a compression reaction force toward the inlets 331, 341 of the suction passage communicating with the cylinder bore in the discharge stroke. Configure.

  The outer peripheral surface 351 of the rotary valve 35 urged toward the cylinder bore 27A in the discharge stroke is pressed against the seal peripheral surface 113 near the inlet 331 of the suction passage 33A communicating with the cylinder bore 27A in the discharge stroke. The outer peripheral surface 361 of the rotary valve 36 biased toward the cylinder bore 28B in the discharge stroke is pressed against the seal peripheral surface 123 in the vicinity of the inlet 341 of the suction passage 34 communicating with the cylinder bore 28B in the discharge stroke. As a result, the refrigerant in the compression chambers 271 and 281 in the cylinder bores 27A and 28B in the discharge stroke hardly leaks from the suction passages 33A and 34, and the volumetric efficiency in the compressor is improved.

(1-2) The thrust bearing 25 is not provided with a thrust load absorbing function, but the thrust bearing 26 is provided with a thrust load absorbing function.
The thrust load absorbing function in the thrust bearing 26 absorbs assembly errors due to dimensional errors of parts. The thrust load absorbing function in the thrust bearing 26 allows the swash plate 23 to move in the directions of the forces F1 and F2 in FIG. That is, the thrust bearing 26 having a thrust load absorbing function allows the rotary valves 35 and 36 to be biased by the compression reaction force toward the inlet of the suction passage communicating with the cylinder bore in the discharge stroke. The configuration in which the thrust bearing 26 provided with the thrust load absorbing function is a part of the compression reaction force transmission means is a simple configuration for suppressing refrigerant leakage from the compression chambers 271 and 281 via the suction passage.

  (1-3) A portion of the rotary shaft 21 on the rotary valve 35 side from the swash plate 23 is a radial bearing including a seal peripheral surface 113 (that is, an internal peripheral surface of the valve housing chamber 37) and an external peripheral surface 351 of the rotary valve 35. Supported only by means. A seal peripheral surface 113 that is an inner peripheral surface of the valve housing chamber 37 is a radial bearing means that supports the rotary shaft 21 via the rotary valve 35. The seal peripheral surface 113 serving as a radial bearing means is the only radial bearing means related to the portion of the rotary shaft 21 on the rotary valve 35 side from the swash plate 23. The seal peripheral surface 113 is a part of a compression reaction force transmitting means that allows the rotary valve 35 to be biased toward the inlet 331 of the suction passage 33A communicating with the cylinder bore 27A in the discharge stroke.

  The portion of the rotary shaft 21 on the rotary valve 36 side from the swash plate 23 is supported only by radial bearing means comprising a seal peripheral surface 123 (that is, an internal peripheral surface of the valve accommodating chamber 38) and an external peripheral surface 361 of the rotary valve 36. The A seal peripheral surface 123 that is an inner peripheral surface of the valve accommodating chamber 38 serves as a radial bearing means that supports the rotary shaft 21 via the rotary valve 36. The seal peripheral surface 123, which is a radial bearing means, is the only radial bearing means for the portion of the rotary shaft 21 on the rotary valve 36 side from the swash plate 23. The seal peripheral surface 123 is a part of a compression reaction force transmission means that allows the rotary valve 36 to be biased toward the inlet 341 of the suction passage 34 that communicates with the cylinder bore 28B in the discharge stroke.

  The configuration in which the rotary shaft 21 is supported by the only radial bearing means related to the rotary shaft 21 on the rotary valve side from the swash plate 23 enhances the action of closing the inlets 331 and 341 of the suction passages 33A and 34A by the rotary valves 35 and 36. .

  (1-4) The inlets 331 and 341 of the suction passages 33A and 34 communicating with the cylinder bores 27A and 28B in the discharge stroke are closed by the pressing of the rotary valves 35 and 36 due to the compression reaction force. This closed state is not greatly affected by the size of the clearance between the outer peripheral surfaces 351 and 361 of the rotary valves 35 and 36 and the seal peripheral surfaces 113 and 123. Therefore, strict management regarding the clearance is not necessary, and the difficulty of leakage of the refrigerant from the compression chambers 271 and 281 in the cylinder bores 27A and 28B in the discharge stroke via the suction passages 33A and 34 is low when the required accuracy of the clearance is low. Almost no change. That is, the volumetric efficiency in the compressor is improved even when the required accuracy of the clearance is low.

  (1-5) The pressing direction of the rotary valve 35 against the seal peripheral surface 113 on the cylinder block 11 side and the pressing direction of the rotary valve 36 against the seal peripheral surface 123 on the cylinder block 12 side are opposite to each other. Therefore, the rotating shaft 21 must be easy to tilt around the center of the diameter of the swash plate 23. The shorter the contact range between the shaft holes 112 and 122 and the peripheral surface of the rotating shaft 21 is in the direction of the axis 211 of the rotating shaft 21, the easier the rotating shaft 21 is inclined. The configuration in which the seal peripheral surfaces 113 and 123 having a smaller diameter than the other portions are provided in the shaft holes 112 and 122 contributes to the inclination of the rotating shaft 21.

(1-6) The configuration in which the rotary valves 35 and 36 are integrally formed on the rotary shaft 21 reduces the number of parts and simplifies the compressor assembly process.
Next, a second embodiment in which the refrigerant suction structure of the present invention is embodied in a variable displacement compressor will be described with reference to FIGS.

  As shown in FIG. 6A, a front housing 40 is joined to the front end of the cylinder block 39, and a rear housing 41 is joined to the rear end of the cylinder block 39. A valve plate 42, a valve forming plate 43 and a retainer forming plate 44 are interposed between the cylinder block 39 and the rear housing 41. A rotating shaft 46 is rotatably supported by the front housing 40 and the cylinder block 39 that form the control pressure chamber 401. The front housing 40 supports the rotating shaft 46 via a radial bearing 47. The rotating shaft 46 is passed through a shaft hole 391 formed in the cylinder block 39, and the cylinder block 39 directly supports the rotating shaft 46.

  A rotating support 48 is fixed to the rotating shaft 46. A pair of guide holes 481 and 482 (shown in FIG. 7) are formed in the rotary support 48. A swash plate 49 (cam body) is supported on the rotating shaft 46 so as to be slidable and tiltable in the direction of the axis 461 of the rotating shaft 46. A shaft hole 493 is formed in the swash plate 49, and the rotation shaft 46 is passed through the shaft hole 493. A pair of guide pins 491 and 492 (shown in FIG. 7) are fixed to the swash plate 49. The swash plate 49 can be tilted in the direction of the axis 461 of the rotation shaft 46 by the linkage of the guide holes 481 and 482 and the guide pins 491 and 492, and can rotate integrally with the rotation shaft 46. The solid line position of the swash plate 49 in FIG. 6A is a position where the swash plate inclination angle is maximum, and the chain line position of the swash plate 49 is a position where the swash plate inclination angle is minimum.

  As shown in FIGS. 6A and 8, single-head pistons 51 and 51 </ b> A are accommodated in the plurality of cylinder bores 50 and 50 </ b> A formed in the cylinder block 39. The single-headed pistons 51 and 51A define a compression chamber 501 in the cylinder bores 50 and 50A. The rotational movement of the swash plate 49 is transmitted to the single-headed pistons 51 and 51A via the shoes 521 and 522, and the single-headed pistons 51 and 51A reciprocate in the cylinder bores 50 and 50A.

  As shown in FIG. 6A, a discharge chamber 411 and a suction chamber 412 are formed in the rear housing 41. A discharge port 421 is formed on the valve plate 42, and a discharge valve 431 is formed on the valve forming plate 43. The discharge valve 431 opens and closes the discharge port 421. A retainer 441 is formed on the retainer forming plate 44. The retainer 441 regulates the opening degree of the discharge valve 431.

  A thrust bearing 53 is interposed between the rotary support 48 and the front housing 40. A shaft seal member 45 is interposed between the front housing 40 and the rotating shaft 46. A passage 462 is formed in the rotating shaft 46. The starting end of the passage 462 is on the inner end surface of the rotating shaft 46 and opens to the suction chamber 412 in the rear housing 41.

  The discharge chamber 411 and the control pressure chamber 401 are connected by a pressure supply passage 54. A capacity control valve 55 is interposed on the pressure supply passage 54. The capacity control valve 55 controls the refrigerant flow rate from the discharge chamber 411 to the control pressure chamber 401. The control pressure chamber 401 and the suction chamber 412 are connected via a passage 462 and a pressure release passage 56. The refrigerant in the control pressure chamber 401 flows out to the suction chamber 412 via the pressure release passage 56. When the pressure in the control pressure chamber 401 increases, the tilt angle of the swash plate 49 decreases, and when the pressure in the control pressure chamber 401 decreases, the tilt angle of the swash plate 49 increases. The capacity control valve 55 adjusts the pressure in the control pressure chamber 401 to control the swash plate tilt angle.

  A seal peripheral surface 392 is formed on the inner peripheral surface of the shaft hole 391 through which the rotation shaft 46 passes. The diameter of the seal peripheral surface 392 is smaller than the diameter of the other inner peripheral surface of the shaft hole 391, and the rotating shaft 46 is directly supported by the cylinder block 39 via the seal peripheral surface 392.

  As shown in FIG. 8, suction passages 58 and 58 </ b> A are formed in the cylinder block 39 so as to communicate the cylinder bores 50 and 50 </ b> A and the shaft hole 391. The inlets 581 of the suction passages 58 and 58 </ b> A are opened on the seal peripheral surface 392. An introduction passage 57 is formed in the rotation shaft 46 so as to communicate with the passage 462. As the rotating shaft 46 rotates, the outlet 571 of the introduction passage 57 communicates intermittently with the inlets 581 of the suction passages 58 and 58A.

  When the cylinder bores 50 and 50A are in the suction stroke state (ie, the stroke in which the single-headed pistons 51 and 51A move from the right side to the left side in FIG. 6A), the outlet 571 and the inlet 581 of the suction passages 58 and 58A communicate with each other. To do. When the cylinder bores 50, 50A are in the suction stroke state, the refrigerant in the passage 462 of the rotating shaft 46 is sucked into the compression chamber 501 of the cylinder bores 50, 50A via the introduction passage 57 and the suction passages 58, 58A.

  When the cylinder bores 50, 50A are in the discharge stroke state (ie, the stroke in which the single-headed pistons 51, 51A move from the left side to the right side in FIG. 6A), the communication between the outlet 571 and the inlet 581 of the suction passages 58, 58A Is cut off. When the cylinder bores 50 and 50A are in the discharge stroke state, the refrigerant in the compression chamber 501 pushes the discharge valve 431 away from the discharge port 421 and is discharged into the discharge chamber 411. The refrigerant discharged into the discharge chamber 411 flows out to an external refrigerant circuit (not shown). The refrigerant flowing out to the external refrigerant circuit is returned to the suction chamber 412.

  As shown in FIG. 6B, the portion of the rotating shaft 46 surrounded by the seal peripheral surface 392 becomes a rotary valve 59 formed integrally with the rotating shaft 46. An outer peripheral surface 591 of the rotary valve 59 surrounded by the seal peripheral surface 392 corresponds to the seal peripheral surface 392. The seal peripheral surface 392 becomes an inner peripheral surface of the valve storage chamber 60 that stores the rotary valve 59.

In the second embodiment, the following effects can be obtained.
(2-1) It is assumed that the cylinder bore 50A shown in FIG. 6A is in the discharge stroke state. The single-headed piston 51A in the cylinder bore 50A in the state of the discharge stroke receives a compression reaction force when discharging the refrigerant in the cylinder bore 50A to the discharge chamber 411 while compressing the refrigerant. A part of this compression reaction force is transmitted to the front housing 40 via the single-headed piston 51 </ b> A, the shoe 521, the swash plate 49, the guide pins 491, 492, the rotation support 48 and the thrust bearing 53. Further, a part of the compression reaction force is transmitted to the rotating shaft 46 through the single-headed piston 51 </ b> A, the shoe 521 and the swash plate 49. The compression reaction force transmitted to the swash plate 49 via the single-headed piston 51A acts on the swash plate 49 as a force indicated by an arrow F3 in FIG. The force F3 urges the swash plate 49 upward in FIG. The guide holes 481 and 482 have a hole shape that is substantially directed in the radial direction of the rotation shaft 46. Therefore, the engagement between the guide pins 491 and 492 and the guide holes 481 and 482 does not hinder the upward movement of the swash plate 49 in FIG. The upward movement of the swash plate 49 in FIG. 6A urges the rotating shaft 46 upward in FIG. 6A through the engagement between the shaft hole 493 and the peripheral surface of the rotating shaft 46. This urging force acts as a moment load centered on the engagement portion between the rotating shaft 46 and the radial bearing 47, and the rotary valve 59 is urged toward the cylinder bore 50A in the discharge stroke state. That is, the compression reaction force transmitted to the rotary shaft 46 via the single-headed piston 51A in the cylinder bore 50A in the discharge stroke state urges the rotary valve 59 toward the cylinder bore 50A in the discharge stroke state.

  The shoe 521, the swash plate 49, the shaft hole 493, and the rotating shaft 46 constitute compression reaction force transmission means for urging the rotary valve 59 by a compression reaction force toward the inlet 581 of the suction passage communicating with the cylinder bore in the discharge stroke. To do.

  The outer peripheral surface 591 of the rotary valve 59 biased toward the cylinder bore 50A in the discharge stroke is pressed against the seal peripheral surface 392 so as to close the inlet 581 of the suction passage 58A communicating with the cylinder bore 50A in the discharge stroke. . As a result, the refrigerant in the compression chamber 501 in the cylinder bore 50A in the discharge stroke hardly leaks from the suction passage 58A, and the volumetric efficiency in the compressor is improved.

  (2-2) A portion of the rotary shaft 46 on the rotary valve 59 side from the swash plate 49 is a radial bearing including a seal peripheral surface 392 (that is, an internal peripheral surface of the valve housing chamber 60) and an external peripheral surface 591 of the rotary valve 59. Supported only by means. A seal peripheral surface 392 that is an inner peripheral surface of the valve housing chamber 60 serves as a radial bearing means that supports the rotary shaft 46 via the rotary valve 59. The seal peripheral surface 392 which is a radial bearing means is the only radial bearing means relating to the portion of the rotary shaft 46 on the rotary valve 59 side from the swash plate 49. The seal peripheral surface 392 is a part of the compression reaction force transmission means. The configuration in which the rotary shaft 46 is supported by the only radial bearing means on the rotary shaft 59 side on the rotary valve 59 side from the swash plate 49 enhances the action of closing the inlet of the suction passage by the rotary valve.

(2-3) The same effects as the items (1-4) to (1-6) in the first embodiment can be obtained.
Next, a third embodiment of FIGS. 9 to 11 will be described. The same reference numerals are used for the same components as those in the first embodiment.

  Rotary valves 62 and 63 are fixed to the rotary shaft 61, and the rotary valves 62 and 63 are accommodated in the valve accommodating chambers 64 and 65. Introduction passages 66 and 67 formed in the rotary valves 62 and 63 communicate with the swash plate chamber 24. The swash plate chamber 24 is a suction chamber that communicates with an external refrigerant circuit (not shown). The outlets 661 and 671 of the introduction passages 66 and 67 and the inlets 331 and 341 of the suction passages 33, 33A, 34, and 34A are intermittently communicated with the rotation of the rotary valves 62 and 63. The refrigerant in the swash plate chamber 24 is sucked into the compression chambers 271 and 281 of the cylinder bores 27, 27A, 28, 28A, and 28B in the suction stroke via the introduction passages 66 and 67 and the suction passages 33, 33A, 34, and 34A. .

  The rotary shaft 61 is sandwiched between a pair of front and rear thrust bearings (thrust bearing means) 68 and 69 to restrict the position of the rotary shaft 61 in the direction of the axis 611. The thrust bearings 68 and 69 are all provided with a thrust load absorbing function.

  The thrust bearings 68 and 69 are part of the compression reaction force transmission means, like the thrust bearing 26 in the first embodiment. In the third embodiment in which the rotary valves 62 and 63 and the rotary shaft 61 are separated, the same effects as those other than the item (1-6) in the first embodiment can be obtained.

In the present invention, the following embodiments are also possible.
(1) A thrust load absorbing function is imparted to the thrust bearing 25 in the first embodiment. By imparting a thrust load absorbing function to the thrust bearing 25, it is further allowed to urge the rotary valves 35 and 36 by the compression reaction force toward the inlet of the suction passage communicating with the cylinder bore in the discharge stroke. Become. As a result, the refrigerant in the compression chamber in the cylinder bore in the discharge stroke can be further prevented from leaking from the suction passage, and the volumetric efficiency in the compressor can be further improved.

  (2) When the rotary valve is integrally formed on the rotating shaft, the shaft diameter of the rotary valve forming portion should be maximized in the vicinity thereof. This brings about the same effect as the item (1-3) in the first embodiment.

  (3) In the first and second embodiments, the rotary valve is pressed against the inner peripheral surface of the valve housing chamber. However, the leakage is not caused by reducing the clearance instead of contacting the rotary valve. It may be configured to prevent.

  (4) The piston has a hollow structure. In this case, for example, it is configured as shown in FIGS. 12 (a) and 12 (b). That is, the double-headed piston 29A shown in FIG. 12A includes a main body portion 701 connected to the shoes 301 and 302, and a lid portion 702 fixed to the main body portion 701 in each reciprocating direction side (front-rear side). It consists of and.

  The double-headed piston 29 </ b> A has a hollow structure having a space 703 surrounded by a main body 701 and a lid 702. In this case, the other double-headed pistons 29 have the same configuration.

  12B includes a connecting portion 711 connected to the shoes 521 and 522, and a head portion 712 fixed to the rear side with respect to the connecting portion 711. The single-headed piston 51 </ b> A has a hollow structure having a space 713 surrounded by a connecting portion 711 and a head portion 712. In this case, the other single-headed piston 51 has the same configuration.

  During the reciprocation of the piston, the piston receives an inertial force in a direction opposite to the compression reaction force. Therefore, the greater this inertial force, the smaller the forces F1, F2, F3 acting on the swash plate 23 due to the compression reaction force. That is, when the piston receives the compression reaction force of the refrigerant, the urging force for pressing the outer peripheral surface of the rotary valve against the seal peripheral surface near the inlet of the suction passage is weakened.

  Therefore, by reducing the weight of the piston with a hollow structure, the inertial force can be reduced as compared with a solid structure piston, and the refrigerant in the compression chamber in the cylinder bore in the discharge stroke leaks from the suction passage. Therefore, it is possible to suppress a decrease in volume efficiency.

  (5) In the first and third embodiments, the swash plate 23 may be configured using a material having a specific gravity greater than that of aluminum such as iron (including an iron alloy). According to this, compared with the case where the swash plate 23 is made of aluminum, the centrifugal force acting on the swash plate 23 during rotation of the rotary shaft 21 is increased without increasing the size of the swash plate 23. be able to.

  When the rotary shaft 21 rotates, the plate-like portion 235 and its rotation center axis are centered on the diameter center portion of the swash plate 23 due to the action of centrifugal force acting on the plate-like portion 235 of the swash plate 23. A force acts to incline in the direction in which the angle formed is a right angle (the clockwise direction in FIGS. 1 and 9). That is, this force acts to urge the rotary valves 35 and 36 toward the inlets 331 and 341 of the suction passage communicating with the cylinder bore in the discharge stroke, similarly to the aforementioned forces F1 and F2.

  In the first and third embodiments, since the swash plate 23 is made of aluminum, the swash plate 23 is comparatively light and acts by the centrifugal force (rotary valves 35 and 36 toward the inlets 331 and 341 of the suction passage). It was difficult to say that the action of energizing In other words, the swash plate 23 is made of a material having a relatively large specific gravity, such as an iron-based material, so that it can be rotated toward the inlets 331 and 341 of the suction passage communicating with the cylinder bore in the discharge stroke. The force that acts to urge the valves 35 and 36 can be increased. Therefore, the refrigerant in the compression chamber in the cylinder bore in the discharge stroke is more difficult to leak from the suction passage, and the volumetric efficiency in the compressor is improved.

(6) The present invention is applied to a so-called wobble variable capacity compressor disclosed in Japanese Patent Laid-Open No. 6-147110.
(7) The present invention is applied to a fixed displacement piston type compressor having a single-headed piston.

(8) The present invention is applied to a piston-type compressor provided with a cam body (for example, a wave cam) having a shape other than a swash plate.
Inventions other than the claims that can be grasped from the above-described embodiment will be described below.

(1) before Symbol rotary valve, the refrigerant suction structure of a piston type compressor is integrally formed on the rotary shaft.
[2] before Symbol cam member is a swash plate, the compressor is a fixed displacement compressor swash plate tilt angle is constant, the swash plate, the piston type compressor made of a metallic material iron Refrigerant suction structure.
[3] before Symbol piston refrigerant suction structure in a piston type compressor having a hollow structure.

The sectional side view of the whole compressor which shows 1st Embodiment. (A) is the sectional view on the AA line of FIG. (B) is a principal part expanded sectional view. (A) is the BB sectional drawing of FIG. (B) is a principal part expanded sectional view. The principal part expanded side sectional view. The principal part expanded side sectional view. A 2nd embodiment is shown and (a) is a sectional side view of the whole compressor. (B) is principal part sectional side view. CC sectional view taken on the line of Fig.6 (a). The DD sectional view taken on the line of Fig.6 (a). The sectional side view of the whole compressor which shows a 3rd embodiment. EE sectional view taken on the line of FIG. FF sectional view taken on the line of FIG. (A) is principal part sectional side view which shows the other example in 1st Embodiment. (B) is principal part sectional drawing which shows the other example in 2nd Embodiment.

Explanation of symbols

  112, 122, 391 ... Shaft holes for supporting the rotating shaft. 113, 123, 392... Seal peripheral surface as an inner peripheral surface of the valve housing chamber. 21, 46, 61... 23, 49... Swash plate (cam body). 25, 26, 68, 69 ... Thrust bearings as thrust bearing means. 27, 27A, 28, 28A, 28B, 50, 50A ... cylinder bores. 271, 281, 501... Compression chamber. 29, 29A ... Double-headed piston. 31, 32, 57, 66, 67... Introduction passage. 311, 321, 571, 661, 671... Exit. 33, 33A, 34, 34A, 58, 58A... Suction passage. 301, 302, 521, 522... Shoe. 331, 341, 581 ... Entrance. 35, 36, 59, 62, 63... Rotary valve. 351, 361, 591 ... The outer peripheral surface of the rotary valve. 37, 38, 60, 64, 65 ... Valve housing chamber. 493 ... A shaft hole through which the rotation shaft passes. 51, 51A ... One-head piston.

Claims (2)

The piston is accommodated in a plurality of cylinder bores arranged around the rotation shaft in the cylinder block, and the piston is interlocked with the rotation of the rotation shaft via a cam body, and is integrated with the rotation shaft, In a piston compressor including a rotary valve having an introduction passage for introducing a refrigerant into a compression chamber partitioned by the piston into the cylinder bore,
A suction passage communicating with the cylinder bore and intermittently communicating with the introduction passage as the rotary valve rotates;
A compression reaction force for transmitting the compression reaction force against the piston in the cylinder bore in the discharge stroke to the rotary valve and urging the rotary valve toward the inlet of the suction passage communicating with the cylinder bore in the discharge stroke A transmission means,
The cylinder block has a shaft hole that rotatably accommodates the rotary valve,
The outlet of the introduction passage is on the outer peripheral surface of the rotary valve, the inlet of the suction passage is on the inner peripheral surface of the shaft hole, and the outer peripheral surface of the rotary valve is on the inner peripheral surface of the shaft hole. It is a radial bearing means that supports the rotating shaft via the rotary valve by being directly supported, and the radial bearing means is the only radial shaft portion related to the portion of the rotating shaft on the rotary valve side from the cam body. bearing means der is,
The piston is a double-headed piston, and a pair of rotary valves corresponding to a pair of front and rear cylinder bores that house the double-headed piston rotate integrally with the rotary shaft, and the cam body is sandwiched between a pair of front and rear thrust bearing means. The position of the rotary shaft in the axial direction is regulated, and at least one of the pair of thrust bearing means forms part of the compression reaction force transmission means, and the thrust forms part of the compression reaction force transmission means The bearing means abuts against an annular ridge formed on the end surface of the cylinder block and an annular ridge formed on the end surface of the cam body, and the diameter of the ridge of the cam body is set to the protrusion of the cylinder block. A refrigerant suction structure in a piston compressor larger than the diameter of the strip. The refrigerant suction structure in a piston compressor according to claim 1, wherein a seal peripheral surface having a smaller diameter than that of another portion is provided on an end portion side of the shaft hole that supports the rotating shaft.

Images