JP2010133308A - Double head piston compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double head piston compressor improving lubricity of a shaft sealing device by drawing lubricating oil from a supply passage to a storage chamber. <P>SOLUTION: A front-side rotary valve 35 is disposed to a rotational shaft 21 of the double head piston compressor 10. In a front-side introduction passage 31 of the front-side rotary valve 35, a virtual line dividing an opening width W of the front-side introduction passage 31 into two sections of a leading side in a rotational direction and a trailing side in the rotational direction of the rotational shaft 21 is a bisector N. An outer peripheral face of the front-side rotary valve 35 includes: a first communication groove 40, of which one end communicates with an area on the leading side in the rotational direction in the front-side introduction passage 31 and the other end communicates with a storage chamber 13b; and a second communication groove 50, of which one end communicates with an area on a trailing side in the rotational direction in the front-side introduction passage 31 and the other end communicates with the housing chamber 13b. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a double-headed piston type compressor provided with a shaft seal device that is disposed in a storage chamber and prevents refrigerant leakage along a peripheral surface of a rotating shaft.

  In general, in a double-headed piston compressor, a front housing is joined to the front side of a pair of cylinder blocks, and a rear housing is joined to the rear side of the cylinder block to constitute the entire housing. A swash plate chamber is defined between the pair of cylinder blocks, and a swash plate integrated with a rotating shaft is accommodated in the swash plate chamber. A double-headed piston is moored on the swash plate, and a compression chamber is defined by a piston in a cylinder bore formed in each cylinder block. As a double-headed piston type compressor, there is one in which a rotary valve is provided on a rotating shaft in order to introduce a refrigerant into a compression chamber. A supply passage communicating with the suction pressure region is formed on the rotating shaft, and an introduction passage for introducing the refrigerant into the compression chamber is formed on the rotary valve so that the compression chamber communicates with the supply passage.

  In the double-headed piston compressor, a shaft seal device is provided between the front housing and the rotating shaft. This shaft seal device is housed in a housing chamber formed in the front housing, and prevents the refrigerant from leaking out of the double-headed piston compressor along the peripheral surface of the rotating shaft. If this shaft seal device does not receive an appropriate amount of lubricating oil, the sliding portion with the rotating shaft will deteriorate early, and the sealing performance will deteriorate early. For this reason, in the double-headed piston type compressor, a lubricating structure for improving the lubricity of the shaft seal device is provided (for example, see Patent Document 1).

  In the double-headed piston compressor of Patent Document 1, as shown in FIG. 5, the front cylinder block 80 and the front housing 81 communicate with a housing chamber 81 a in which a shaft seal device 87 is housed and a swash plate chamber 83. A communication passage 82 is formed. In addition, one communication groove 84 a that communicates with the introduction passage 85 a of the rotary valve 85 and the storage chamber 81 a is formed on the outer peripheral surface of the rotating shaft 84. The supply passage 86 in the rotating shaft 84 and the swash plate chamber 83 are communicated with each other by a communication passage 82 and a communication groove 84a through the storage chamber 81a.

For this reason, the refrigerant in the swash plate chamber 83 flows to the supply passage 86 via the communication passage 82, the storage chamber 81a, the communication groove 84a, and the introduction passage 85a. Therefore, the lubricating oil contained in the refrigerant that has flowed into the storage chamber 81a contributes to the lubrication of the shaft seal device 87.
JP 2007-32445 A

  By the way, in the double-headed piston compressor of Patent Document 1, the refrigerant in the swash plate chamber 83 is relatively hot due to the influence of blow-by gas or the like. For this reason, the lubricating oil contained in this high-temperature refrigerant also becomes high temperature, and even if the lubricating oil is introduced into the storage chamber 81a together with the refrigerant in the swash plate chamber 83, it is difficult to improve the lubricity of the shaft seal device 87. was there.

  The present invention has been made paying attention to such problems existing in the prior art, and its purpose is to improve the lubricity of the shaft seal device by drawing lubricating oil from the supply passage into the storage chamber. It is an object of the present invention to provide a double-headed piston type compressor capable of achieving the above.

  In order to solve the above problem, the invention according to claim 1 is a front housing, a rear housing, a cylinder block provided between the front housing and the rear housing and having a plurality of cylinder bores; A double-ended piston slidably inserted into a plurality of cylinder bores, a rotary shaft rotatably supported in a pair of shaft holes formed in the cylinder block, and a swash plate chamber formed by the cylinder block; A swash plate that rotates in the swash plate chamber together with the rotating shaft and reciprocates the double-headed piston in the cylinder bore; a compression chamber partitioned by the double-headed piston into a front housing side and a rear housing side in the cylinder bore; A supply passage formed in the rotary shaft and communicating with the suction pressure region, and the front housing A suction passage formed in the cylinder block so as to communicate with the compression chamber on the side, and a refrigerant provided from the supply passage to the compression chamber on the front housing side through the suction passage. Formed between a rotary valve having an introduction passage for introducing the rotary shaft and rotatably supported by the shaft hole, and an outer peripheral surface of the rotary shaft opposed to the inner peripheral surface of the front housing. A double-headed piston compressor provided with a storage chamber and a shaft seal device disposed in the storage chamber for preventing refrigerant leakage along the rotation shaft, wherein the rotation shaft is disposed in the introduction passage. When an imaginary line that bisects the opening width of the introduction passage on the rotation direction leading side and the rotation direction trailing side is a bisector, the rotary valve has an outer peripheral surface on the introduction passage. One end communicates with a region on the preceding side in the rotational direction and one end communicates with a region on the downstream side in the rotational direction of the introduction passage, and the other end communicates with the storage chamber. The gist is that a second communication groove communicating with the storage chamber is formed.

  According to this, in the introduction passage of the rotary valve, the first communication groove and the second communication groove have different compression chambers that communicate with each other via the suction passage. The compression chamber in which the first communication groove communicates through the suction passage is in the initial stage of the suction stroke, and the pressure in the compression chamber is lower than the pressure in the storage chamber. On the other hand, the compression chamber in which the second communication groove communicates via the suction passage is in the later stage of the suction stroke, and the pressure in the compression chamber is higher than the pressure in the storage chamber. Therefore, the flow of refrigerant from the storage chamber to the introduction passage is formed through the first communication groove using the pressure difference between the compression chamber and the storage chamber through the suction passage, and the second communication groove is used. Thus, a refrigerant flow from the introduction passage to the storage chamber is formed. As a result, a refrigerant path that circulates between the storage chamber and the introduction passage can be formed, and the lubricating oil can be drawn together with the refrigerant from the supply passage to the storage chamber via the introduction passage. The refrigerant drawn into the storage chamber from the introduction passage is a refrigerant flowing through the supply passage, and has a low temperature and a low pressure as compared with the refrigerant in the swash plate chamber, and the lubricating oil contained in the low temperature and low pressure refrigerant also becomes a low temperature. Yes. Therefore, the lubricity of the shaft seal device can be improved by the lubricating oil that is in a low temperature state and has a high viscosity.

  The first communication groove is formed so that the one end is connected to a communication start timing portion to the suction passage in the introduction passage, and the second communication groove is connected to the suction passage in the introduction passage. It may be formed so as to be connected to the communication end timing portion.

  According to this, since the region connected to the communication start timing portion in the introduction passage communicates with the suction passage first, the first communication groove connected to this communication start timing portion is the compression chamber immediately after the start of the suction stroke, that is, It communicates with the compression chamber in the lowest pressure state during the suction stroke. Therefore, since the pressure difference between the compression chamber and the storage chamber via the suction passage becomes the largest, it is possible to reliably draw a large amount of refrigerant from the storage chamber into the introduction passage. On the other hand, the region connected to the communication end timing portion in the introduction passage communicates with the suction passage last, so the second communication groove communicating with this communication end timing portion is the compression chamber immediately before the end of the suction stroke, that is, the suction stroke. It communicates with the compression chamber in the highest pressure state. Therefore, since the pressure difference between the compression chamber and the storage chamber via the suction passage becomes the largest, it is possible to reliably draw a large amount of refrigerant from the introduction passage into the storage chamber.

  Further, the first communication groove and the second communication groove are formed such that a distance between the first communication groove and the second communication groove is increased from the one end to the other end along the axial direction of the rotating shaft. May be.

  According to this, the first communication groove extends obliquely from the introduction passage toward the rotation direction leading side. For this reason, the inertial force by rotation of a rotating shaft can be generated in the lubricating oil in the first communication groove, and the lubricating oil in the first communication groove can be drawn into the introduction passage. The second communication groove extends obliquely toward the downstream side in the rotation direction of the introduction passage. For this reason, an inertial force can be applied to the lubricating oil in the second communication groove, and the lubricating oil in the second communication groove can be drawn into the storage chamber.

  Further, in the introduction passage, a partial region near the front housing along the axial direction of the rotation shaft is opposed to the inner peripheral surface of the shaft hole, and the introduction passage is provided on the inner peripheral surface of the shaft hole. A collision portion that causes the refrigerant to collide may be formed in a portion facing a part of the region near the front housing.

  As described in Japanese Patent Application Laid-Open No. 7-63165 (hereinafter referred to as reference), a part of the introduction passage (inhalation passage in the reference) near the front housing faces the shaft hole (through hole in the reference). First, when facing the suction passage (suction port in the reference), the refrigerant in the supply passage (suction passage in the reference) is sucked into the suction passage as it is. Then, the lubricating oil contained in the refrigerant also passes through the introduction passage and the suction passage and is sucked into the compression chamber as it is. On the other hand, according to the double-headed piston compressor of the fourth aspect, the refrigerant traveling from the supply passage to the suction passage through the introduction passage is collided with the collision portion, and is included in the refrigerant using this collision. Lubricating oil can be separated from the refrigerant. As a result, the amount of lubricating oil sucked into the compression chamber can be reduced, and a large amount of lubricating oil drifts in the vicinity of the introduction passage so that a large amount of lubricating oil is drawn into the accommodation chamber through the second communication groove. Can do.

  According to the present invention, it is possible to improve the lubricity of the shaft seal device by drawing lubricating oil from the supply passage into the storage chamber.

  Hereinafter, an embodiment of a double-headed piston compressor embodying the present invention will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view of a double-headed piston compressor 10 (hereinafter simply referred to as a compressor 10) of the present embodiment. In the following description, for the “front (front)” and “rear (rear)” of the compressor 10, the direction of the arrow Y shown in FIG.

  As shown in FIG. 1, the entire housing of the compressor 10 includes a pair of joined cylinder blocks 11, 12, a front housing 13 joined to the front (front) cylinder block 11, and a rear side (rear side). ) And the rear housing 14 joined to the cylinder block 12. The cylinder blocks 11, 12, the front housing 13 and the rear housing 14 are fastened together by a plurality of bolts B (five in this embodiment, only one bolt B is shown in FIG. 1). The front housing 13 is formed with a discharge chamber 13a, and the rear housing 14 is formed with a discharge chamber 14a and a suction chamber 14b. The suction chamber 14 b constitutes a suction pressure region in the compressor 10.

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

  A rotary shaft 21 is inserted through shaft holes 11a and 12a penetrating the cylinder blocks 11 and 12, and the rotary shaft 21 is rotatably supported by the shaft holes 11a and 12a. A storage chamber 13b is defined between the inner peripheral surface of the front housing 13 and the outer peripheral surface of the rotary shaft 21 facing the inner peripheral surface, and a lip seal type shaft seal device is provided in the storage chamber 13b. 22 is disposed. The shaft seal device 22 prevents refrigerant leakage from the inside of the compressor 10 to the outside of the compressor 10 along the outer peripheral surface of the rotating shaft 21 by slidingly contacting the outer peripheral surface of the rotating shaft 21.

  A swash plate 23 that rotates integrally with the rotary shaft 21 is fixed to the rotary shaft 21. The swash plate 23 is disposed in a swash plate chamber 24 defined between the pair of cylinder blocks 11 and 12. A thrust bearing 25 is interposed between the end face of the front cylinder block 11 and the annular base 23 a of the swash plate 23. A thrust bearing 26 is interposed between the end face of the cylinder block 12 on the rear side and the base 23 a of the swash plate 23. The thrust bearings 25 and 26 regulate movement in a direction along the central axis L of the rotating shaft 21 (hereinafter referred to as an axial direction) with the swash plate 23 interposed therebetween.

  A plurality of cylinder bores 27 (five in the present embodiment, only one cylinder bore 27 is shown in FIG. 1) are formed in the front cylinder block 11 so as to be arranged around the rotation shaft 21. The rear cylinder block 12 is formed with a plurality of cylinder bores 28 (five in the present embodiment, only one cylinder bore 28 is shown in FIG. 1) arranged around the rotary shaft 21. A double-headed piston 29 is slidably inserted into the cylinder bores 27 and 28 which are paired in the front and rear.

  The rotational movement of the swash plate 23 that rotates integrally with the rotary shaft 21 is transmitted to the double-headed piston 29 through a pair of shoes 30 provided with the swash plate 23 interposed therebetween, and the double-headed piston 29 moves back and forth in the cylinder bores 27 and 28. Reciprocates (slides). In the cylinder bores 27 and 28, a front-side compression chamber 27a is defined on the front housing 13 side and a rear-side compression chamber 28a is defined on the rear housing 14 side by a double-headed piston 29.

  A supply passage 21 a extending along the axial direction of the rotation shaft 21 is formed in the rotation shaft 21. The rear end of the supply passage 21a opens to the suction chamber 14b in the rear housing 14, and the supply passage 21a and the suction chamber 14b communicate with each other. In the rotary shaft 21, a front-side introduction passage 31 is formed at a position facing the inner peripheral surface of the front-side shaft hole 11a, and a rear-side introduction passage is formed at a position facing the inner peripheral surface of the rear-side shaft hole 12a. 32 is formed. The front side introduction passage 31 and the rear side introduction passage 32 are formed at positions shifted by 180 degrees in the circumferential direction of the rotating shaft 21.

  Each of the front-side introduction passage 31 and the rear-side introduction passage 32 communicates with the supply passage 21a. As shown in FIG. 2A, each of the front-side introduction passage 31 and the rear-side introduction passage 32 (only the front-side introduction passage 31 is shown in FIG. 2A) has a long side along the axial direction of the rotary shaft 21. Is formed in a quadrangular shape (rectangular shape) with a short side extending along the circumferential direction of the rotating shaft 21.

  As shown in FIG. 1, a plurality of front suction passages 33 are formed in the front cylinder block 11 so as to communicate the front compression chambers 27a with the shaft holes 11a. The inlet of each front side suction passage 33 opens on the inner peripheral surface of the shaft hole 11a, and the outlet of each front side suction passage 33 opens toward the front side compression chamber 27a of the communicating cylinder bore 27. A plurality of rear-side suction passages 34 are formed in the rear-side cylinder block 12 so as to communicate the rear-side compression chambers 28a with the shaft holes 12a. The inlet of each rear side suction passage 34 opens on the inner peripheral surface of the shaft hole 12a, and the outlet of each rear side suction passage 34 opens toward the rear side compression chamber 28a of the communicating cylinder bore 28.

  As the rotary shaft 21 rotates, the front side introduction passage 31 intermittently communicates with the front side suction passage 33, and the rear side introduction passage 32 intermittently communicates with the rear side suction passage 34. The portion of the rotary shaft 21 surrounded by the front-side shaft hole 11a is a front-side rotary valve 35, and the portion of the rotary shaft 21 surrounded by the rear-side shaft hole 12a is the rear-side rotary valve 36. It has become.

  As shown in FIG. 4, the edge 31 f that is the edge of the front-side introduction passage 31 and is closest to the front housing 13 is the edge of the front-side suction passage 33 that is closest to the front housing 13. It is located closer to the front housing 13 than 33f. For this reason, a part of the front side introduction passage 31 near the front housing 13 faces the inner peripheral surface of the shaft hole 11a. In the inner peripheral surface of the shaft hole 11a, a portion of the front side introduction passage 31 that faces a part of the front side introduction passage 31 is a collision portion 11c where the refrigerant passing through the front side introduction passage 31 collides. Yes.

  In the compressor 10 configured as described above, when the front side compression chamber 27a is in the suction stroke state (that is, the stroke in which the double-headed piston 29 moves from the left side to the right side in FIG. 1), as shown in FIG. The introduction passage 31 and the front side suction passage 33 communicate with each other. When the cylinder bore 27 is in the suction stroke state, the refrigerant in the supply passage 21a is sucked into the front side compression chamber 27a via the front side introduction passage 31 and the front side suction passage 33. The position where the volume of the front side compression chamber 27a is maximized is defined as the bottom dead center of the double-headed piston 29.

  On the other hand, when the front side compression chamber 27a is in a discharge stroke state (ie, a stroke in which the double-headed piston 29 moves from the right side to the left side in FIG. 1), as shown in FIG. Communication with the passage 33 is blocked. When the cylinder bore 27 is in the discharge stroke state, the refrigerant in the front side compression chamber 27a pushes the discharge valve 16a away from the discharge port 15a and is discharged into the discharge chamber 13a. The position where the volume of the front side compression chamber 27a is minimized is defined as the top dead center of the double-headed piston 29. The refrigerant discharged into the discharge chamber 13a flows out to an external refrigerant circuit (not shown). In addition, lubricating oil is put in the refrigerating circuit composed of the compressor 10 (particularly the swash plate chamber 24) and the external refrigerant circuit, and this lubricating oil flows in the refrigerating circuit together with the refrigerant.

  Further, when the rear side compression chamber 28a is in the suction stroke state (that is, the stroke in which the double-headed piston 29 moves from the right side to the left side in FIG. 1), the rear side introduction passage 32 and the rear side suction passage 34 communicate with each other. When the rear side compression chamber 28a is in the suction stroke state, the refrigerant in the supply passage 21a of the rotating shaft 21 is sucked into the rear side compression chamber 28a via the rear side introduction passage 32 and the rear side suction passage 34. The position where the volume of the rear side compression chamber 28a is maximized is defined as the bottom dead center of the double-headed piston 29.

  On the other hand, when the rear side compression chamber 28a is in the discharge stroke state (ie, the stroke in which the double-headed piston 29 moves from the left side to the right side in FIG. 1), the communication between the rear side introduction passage 32 and the rear side suction passage 34 is cut off. Is done. When the rear side compression chamber 28a is in the discharge stroke state, the refrigerant in the rear side compression chamber 28a pushes the discharge valve 19a away from the discharge port 18a and is discharged into the discharge chamber 14a. The position where the volume of the rear side compression chamber 28a is maximized is defined as the bottom dead center of the double-headed piston 29. The refrigerant discharged into the discharge chamber 14a flows out to the external refrigerant circuit. The refrigerant that has flowed into the external refrigerant circuit returns to the suction chamber 14b.

  In the compressor 10, a communication passage 46 is formed in the front housing 13, the valve plate 15, the valve forming plate 16, the retainer forming plate 17, and the front cylinder block 11. The communication passage 46 is located below the cylinder block 11 and passes between the two adjacent cylinder bores 27, 27. The rear end of the communication passage 46 opens to the swash plate chamber 24, and the front end of the communication passage 46 opens to the accommodation chamber 13b. In other words, the communication passage 46 communicates the storage chamber 13 b and the swash plate chamber 24.

  Next, the first communication groove 40 and the second communication groove 50 provided in the front side rotary valve 35 will be described. First, the direction indicated by the arrow R in FIG. A virtual line that bisects the opening width W of the front-side introduction passage 31 along the rotation direction of the rotation shaft 21 is defined as a bisector N. Further, in the front side introduction passage 31, among the regions bisected by the bisector N, the region that communicates first with the front suction passage 33 (the region that communicates earlier) is the rotation axis. 21 is an area on the preceding side in the rotational direction, and an area on the side that communicates later (area on the side that communicates later) is an area on the downstream side in the rotational direction.

  Further, in the front side introduction passage 31, an end edge that is positioned at the forefront of the rotation direction leading side and extends in the axial direction of the rotation shaft 21 is defined as a communication start timing portion K in the front side introduction passage 31. This communication start timing portion K is connected to the front suction passage 33 immediately after the suction stroke in the front compression chamber 27a starts, that is, immediately after the double-headed piston 29 starts to move from the top dead center toward the bottom dead center. It is the part which first opposes. For this reason, a region connected to the communication start timing portion K in the front side introduction passage 31, that is, a region on the preceding side in the rotation direction communicates first with the front side suction passage 33.

  On the other hand, in the front side introduction passage 31, the end edge located at the rearmost end on the rear side in the rotation direction and extending in the axial direction of the rotation shaft 21 is defined as a communication end timing portion S in the front side introduction passage 31. This communication end timing portion S is a portion facing the front-side suction passage 33 immediately before the end of the suction stroke in the front-side compression chamber 27a, that is, immediately before the double-headed piston 29 reaches the bottom dead center. For this reason, the region connected to the communication end timing portion S in the front side introduction passage 31, that is, the region on the downstream side in the rotation direction, communicates with the front side suction passage 33 last.

  As shown in FIGS. 2A and 2B, in the front-side rotary valve 35, a first communication groove 40 and a second communication groove 50 are formed on the outer peripheral surface of the rotating shaft 21. The first communication groove 40 is formed so as to communicate with a region on the front side in the rotational direction with respect to the bisector N of the front side introduction passage 31. The first communication groove 40 communicates with a corner portion of the front-side introduction passage 31 so that a first groove opening 40 a serving as a rear end (one end) is connected to the communication start timing portion K in the front-side introduction passage 31. The first communication groove 40 is formed so that the second groove port 40b serving as the front end (the other end) communicates with the storage chamber 13b. For this reason, the first communication groove 40 communicates with the supply passage 21a via the front side introduction passage 31, and the storage chamber 13b and the supply passage 21a connect the first communication groove 40 and the front side introduction passage 31 with each other. Communicated through.

  The second communication groove 50 is formed so as to communicate with a region on the downstream side in the rotational direction with respect to the bisector N of the front side introduction passage 31. The second communication groove 50 communicates with a corner portion of the front-side introduction passage 31 so that a first groove port 50 a serving as a rear end (one end) is connected to the communication end timing portion S in the front-side introduction passage 31. Further, the second communication groove 50 is formed such that a second groove port 50b serving as a front end (the other end) communicates with the storage chamber 13b. For this reason, the second communication groove 50 communicates with the supply passage 21a via the front side introduction passage 31, and the storage chamber 13b and the supply passage 21a connect the second communication groove 50 and the front side introduction passage 31 with each other. Communicated through.

  Each of the first communication groove 40 and the second communication groove 50 has an interval between the first communication groove 40 and the second communication groove 50 along the axial direction of the rotating shaft 21 from the front-side introduction passage 31 toward the storage chamber 13b. It is formed in a square shape so as to spread. That is, as shown in FIG. 2C, the first communication groove 40 extends obliquely with respect to the first groove opening 40a such that the second groove opening 40b is located on the rotation direction leading side. On the other hand, as shown in FIG. 2D, the second communication groove 50 extends obliquely with respect to the first groove opening 50a so that the second groove opening 50b is located on the downstream side in the rotation direction. Therefore, the space between the first communication groove 40 and the second communication groove 50 is narrow on the front side introduction passage 31 side and wide on the accommodation chamber 13b side.

Next, the operation of the compressor 10 having the above configuration will be described.
In the compressor 10, the refrigerant pressure (discharge pressure) in the front-side compression chamber 27 a and the rear-side compression chamber 28 a in the discharge stroke state is higher than the pressure in the swash plate chamber 24. Therefore, the high-temperature and high-pressure refrigerant (blow-by gas) in the front-side compression chamber 27a and the rear-side compression chamber 28a in the discharge stroke is slightly between the peripheral surface of the double-headed piston 29 and the peripheral surfaces of the cylinder bores 27 and 28. A slight leak from the gap into the swash plate chamber 24 occurs. Such refrigerant leakage makes the pressure in the swash plate chamber 24 slightly higher than the pressure in the supply passage 21a. Therefore, the refrigerant (lubricating oil) in the swash plate chamber 24 flows into the storage chamber 13b through the communication passage 46, and further flows into the supply passage 21a through the first communication groove 40. Therefore, the storage chamber 13 b has the same pressure as the swash plate chamber 24.

  On the other hand, in the front side compression chamber 27a immediately after the start of the suction stroke (initial stage of the suction stroke), when the double-headed piston 29 moves from the top dead center side to the bottom dead center side, the pressure in the front side compression chamber 27a is lower than the pressure in the supply passage 21a. Become.

  3A and 3B, the communication start timing portion K of the front side introduction passage 31 faces the front side suction passage 33, and the front side introduction passage 31, the front side suction passage 33, Communicate. At this communication timing (immediately after the start of the suction stroke), the pressure in the front side compression chamber 27a is lower than the pressure in the supply passage 21a, so that the refrigerant in the supply passage 21a passes from the front side introduction passage 31 through the front side suction passage 33. And sucked into the front compression chamber 27a.

  In addition, at the timing when the front side introduction passage 31 and the front side suction passage 33 communicate with each other, the first communication groove 40 communicates with the front side compression chamber 27 a via the front side suction passage 33. At this time, the pressure in the front side compression chamber 27a is the lowest in the suction stroke and is lower than the pressure in the storage chamber 13b. For this reason, the pressure difference between the front side compression chamber 27a and the storage chamber 13b via the front side suction passage 33 becomes the largest, and as shown by the arrow X1 in FIG. ) Is drawn into the front-side introduction passage 31 via the first communication groove 40, and a refrigerant flow from the storage chamber 13b to the front-side introduction passage 31 is formed.

  Further, the first communication groove 40 intersects the axial direction of the rotary shaft 21 and extends obliquely from the front-side introduction passage 31 toward the rotational direction leading side. That is, in the first communication groove 40, the first groove port 40a communicating with the front side introduction passage 31 is located on the downstream side in the rotational direction from the second groove port 40b. For this reason, the inertial force due to the rotation of the rotary shaft 21 acts on the lubricating oil in the first communication groove 40, and the lubricating oil in the first communication groove 40 is drawn into the front side introduction passage 31 via the first communication groove 40. It is.

  On the other hand, at the timing when the communication start timing portion K faces the front side suction passage 33, the communication end timing portion S is connected to another front side suction passage 33 (hereinafter referred to as another front side suction passage 33A) on the downstream side in the rotation direction. To be described). The second communication groove 50 communicates with another front side compression chamber 27a via another front side suction passage 33A. In the other front side compression chamber 27a, the double-headed piston 29 is already at a position close to the bottom dead center (immediately before the end of the intake stroke (late stage of the intake stroke)), and has the highest pressure in the intake stroke. For this reason, the pressure difference between the other front side compression chamber 27a and the storage chamber 13b via the front side suction passage 33 becomes the largest. Therefore, as indicated by an arrow X2 in FIG. 3B, the refrigerant (lubricating oil) in the front side introduction passage 31 is drawn into the accommodation chamber 13b through the second communication groove 50 and is also accommodated from the front side introduction passage 31. A refrigerant flow into the chamber 13b is formed.

  The second communication groove 50 intersects the axial direction of the rotary shaft 21 and extends obliquely from the front-side introduction passage 31 toward the downstream side in the rotational direction. That is, in the second communication groove 50, the first groove port 50a communicating with the front-side introduction passage 31 is positioned on the rotation direction leading side with respect to the second groove port 50b. For this reason, an inertia force acts on the lubricating oil in the second communication groove 50, and the lubricating oil in the second communication groove 50 passes through the second communication groove 50 and is drawn into the storage chamber 13 b.

  Therefore, by forming the first communication groove 40 and the second communication groove 50 on the rotating shaft 21, a flow of refrigerant circulating between the front side introduction passage 31 and the storage chamber 13b is formed. Therefore, the low-temperature and low-pressure refrigerant flowing through the supply passage 21a is drawn into the storage chamber 13b via the second communication groove 50, and low-temperature lubricating oil is supplied to the shaft seal device 22 in the storage chamber 13b together with the low-temperature and low-pressure refrigerant. Is done.

  Further, when the refrigerant flows from the supply passage 21a toward the front side suction passage 33, the refrigerant collides with the collision portion 11c. Then, in the vicinity of the front-side introduction passage 31, the refrigerant collides with the collision portion 11c, so that the lubricating oil contained in the refrigerant is separated from the refrigerant by inertial separation. Then, the refrigerant separated in the front-side introduction passage 31 is drawn into the accommodation chamber 13 b along with the refrigerant flow to the accommodation chamber 13 b via the second communication groove 50 and supplied to the shaft seal device 22.

  Thereafter, when the first communication groove 40 and the second communication groove 50 face the inner peripheral surface of the shaft hole 11a as the rotary shaft 21 rotates, the refrigerant circulating between the front-side introduction passage 31 and the storage chamber 13b is removed. The flow is stopped.

According to the above embodiment, the following effects can be obtained.
(1) The first communication groove 40 and the second communication groove 50 that allow the front-side introduction passage 31 and the storage chamber 13b to communicate with each other are formed in the front-side rotary valve 35. Further, the first groove opening 40a of the first communication groove 40 is communicated with the region on the front side in the rotation direction of the front side introduction passage 31, and the first groove opening 50a of the second communication groove 50 is rotated in the rotation direction of the front side introduction passage 31. Communicating with the trailing area. For this reason, using the pressure difference between the front side compression chamber 27a and the storage chamber 13b via the front side suction passage 33, the refrigerant flows from the storage chamber 13b to the front side introduction passage 31 via the first communication groove 40. In addition to forming a flow, it is possible to form a flow of the refrigerant from the front side introduction passage 31 to the accommodation chamber 13b via the second communication groove 50. Accordingly, a refrigerant path that circulates between the storage chamber 13b and the front-side introduction passage 31 can be formed, and the lubricating oil can be drawn into the storage chamber 13b through the front-side introduction passage 31 together with the refrigerant in the supply passage 21a. Since the refrigerant drawn into the storage chamber 13b from the front-side introduction passage 31 is a refrigerant flowing through the supply passage 21a and has a low temperature and low pressure, low-temperature lubricating oil can be drawn into the storage chamber 13b together with the refrigerant. Therefore, the lubricity of the shaft seal device 22 can be improved by the low temperature lubricating oil. As a result, the sliding portion of the shaft seal device 22 can be effectively lubricated and cooled to reduce the wear amount of the shaft seal device 22.

  (2) The first groove opening 40 a of the first communication groove 40 communicates with the front side introduction passage 31 so as to be connected to the communication start timing portion K in the front side introduction passage 31. On the other hand, the first groove port 50 a of the second communication groove 50 communicates with the front side introduction passage 31 so as to be connected to the communication end timing portion S in the front side introduction passage 31. Therefore, the first communication groove 40 can be communicated with the front side compression chamber 27a immediately after the start of the suction stroke, and the pressure difference between the front side compression chamber 27a and the storage chamber 13b via the front side suction passage 33 is maximized. Thus, a large amount of lubricating oil can be reliably drawn from the storage chamber 13b into the front side introduction passage 31. Further, the second communication groove 50 can be communicated with the front side compression chamber 27a immediately before the end of the suction stroke, and the pressure difference between the front side compression chamber 27a and the storage chamber 13b via the front side suction passage 33 is maximized. Thus, it is possible to reliably draw a large amount of lubricating oil from the front side introduction passage 31 into the accommodation chamber 13b.

  (3) The first communication groove 40 extends obliquely from the communication start timing portion K of the front side introduction passage 31 toward the rotation direction leading side. For this reason, an inertial force due to the rotation of the rotary shaft 21 is generated in the lubricating oil in the first communication groove 40, and the lubricating oil in the first communication groove 40 is drawn into the front side introduction passage 31 from the first communication groove 40. Can do. Therefore, in addition to the pressure difference between the front side compression chamber 27a and the storage chamber 13b, the lubricating oil can be drawn into the front side introduction passage 31 by forming the first communication groove 40 obliquely.

  (4) The second communication groove 50 extends obliquely from the communication end timing portion S of the front side introduction passage 31 toward the rear side in the rotation direction. For this reason, an inertia force can be applied to the lubricating oil in the second communication groove 50, and the lubricating oil in the second communication groove 50 can be drawn into the storage chamber 13 b from the second communication groove 50. Therefore, in addition to the pressure difference between the storage chamber 13b and the front side compression chamber 27a, the lubricating oil can be drawn into the storage chamber 13b by forming the second communication groove 50 obliquely.

  (5) On the inner peripheral surface of the shaft hole 11a, a portion of the front side introduction passage 31 that faces the storage chamber 13b side is a collision portion 11c where the refrigerant collides. Therefore, when the refrigerant passing through the front side introduction passage 31 collides with the collision portion 11c, the lubricating oil contained in the refrigerant can be efficiently separated. As a result, a large amount of lubricating oil can be drifted in the vicinity of the front-side introduction passage 31, and a large amount of lubricating oil can be drawn into the storage chamber 13 b via the second communication groove 50.

  (6) The swash plate chamber 24 and the storage chamber 13 b communicate with each other via the communication passage 46. For this reason, the lubricating oil of the swash plate chamber 24 can be supplied to the storage chamber 13b together with the refrigerant using the pressure difference among the swash plate chamber 24, the storage chamber 13b, and the supply passage 21a. Therefore, the shaft seal device 22 in the storage chamber 13 b can be lubricated by the lubricating oil from the swash plate chamber 24.

In addition, you may change the said embodiment as follows.
In the embodiment, the length of the front side introduction passage 31 along the axial direction of the rotary shaft 21 and the length of the front side suction passage 33 along the axial direction of the rotary shaft 21 are the same, and the front side introduction passage The end edge closest to the front housing 13 may be opposed to the end edge closest to the front housing 13 of the front side suction passage 33. The entire front side introduction passage 31 may be opposed to the entire front side suction passage 33 so that the collision portion 11c does not have to be formed.

  In the embodiment, the first communication groove 40 may be formed to extend linearly from the communication start timing portion K along the axial direction of the rotary shaft 21, and the second communication groove 50 is connected to the communication end timing portion S. May be formed so as to extend linearly along the axial direction of the rotary shaft 21.

  In the embodiment, if the first groove 40a of the first communication groove 40 is on the preceding side in the rotational direction with respect to the bisector N, the first communication groove 40 is connected to the front side introduction passage 31 on the downstream side in the rotational direction with respect to the communication start timing portion K. You may communicate. Further, the second communication groove 50 communicates with the front side introduction passage 31 on the front side in the rotational direction with respect to the communication end timing portion S if the first groove port 50a is on the downstream side in the rotational direction with respect to the bisector N. May be.

In the embodiment, the communication passage 46 that communicates the swash plate chamber 24 and the storage chamber 13b may not be provided.
In the embodiment, the suction port that eliminates the rear rotary valve 36 of the rotary shaft 21 and connects the rear compression chamber 28a and the suction chamber 14b to the valve plate 18, the valve forming plate 19, and the retainer forming plate 20 Further, a suction valve is formed on the valve forming plate 19. The refrigerant suction structure for the rear side compression chamber 28a may be a suction valve that opens and closes by a differential pressure between the suction chamber 14b and the rear side compression chamber 28a.

Next, the technical idea that can be grasped from the above embodiment and other examples will be described below.
(1) A suction passage communicating with the compression chamber on the rear housing side is formed in the cylinder block, and a rear housing side of the rotating shaft is provided on the rear housing side from the supply passage through the suction passage. The double-headed piston type according to any one of claims 1 to 4, further comprising an introduction passage for introducing a refrigerant into the compression chamber and rotatably supported by the shaft hole. Compressor.

The longitudinal cross-sectional view which shows the double-headed piston type compressor of embodiment. (A) is a partial plan view showing the front-side rotary valve, (b) is a cross-sectional view taken along the line 2b-2b of FIG. 2 (a) showing the front-side rotary valve, and (c) is the front side in the rotational direction of the front-side rotary valve. (D) is a partial side view showing the rear side in the rotation direction of the front rotary valve. (A) is sectional drawing which shows the timing which the front side introduction channel | path communicated with the front side suction passage, (b) is the figure which expand | deployed the outer peripheral surface of the front side rotary valve in planar shape. The fragmentary sectional view which shows the front side rotary valve periphery. The fragmentary sectional view which shows background art.

Explanation of symbols

  K: Communication start timing section, N: bisector, S: Communication end timing section, W: Opening width, 10: Double-head piston compressor, 11, 12: Cylinder block, 11a, 12a ... Shaft hole, 11c ... Collision part, 13 ... front housing, 13b ... storage chamber, 14 ... rear housing, 14b ... suction chamber as suction pressure region, 21 ... rotating shaft, 21a ... supply passage, 22 ... shaft seal device, 23 ... swash plate, 24 ... Swash plate chambers 27, 28 ... Cylinder bores, 27a ... Front side compression chambers as compression chambers on the front housing side, 28a ... Rear side compression chambers as compression chambers on the rear housing side, 29 ... Double-headed pistons, 31 ... Front side introduction Passage 33, front side suction passage, 35 ... front side rotary valve, 40 ... first communication groove, 40a, 50a ... first groove port as one end, 40b, 50b ... other The second Mizoguchi, 50 ... the second communication groove of as.

Claims (4)

A front housing;
A rear housing;
A cylinder block having a plurality of cylinder bores provided between the front housing and the rear housing;
A double-ended piston slidably inserted into the plurality of cylinder bores;
A rotating shaft rotatably supported in a pair of shaft holes formed in the cylinder block;
A swash plate chamber formed by the cylinder block;
A swash plate that rotates in the swash plate chamber together with the rotating shaft and reciprocates the double-headed piston in the cylinder bore;
A compression chamber partitioned by the double-headed piston into a front housing side and a rear housing side in the cylinder bore;
A supply passage formed in the rotating shaft and communicating with the suction pressure region;
A suction passage formed in the cylinder block so as to communicate with the compression chamber on the front housing side;
The rotary shaft is provided on the front housing side, has an introduction passage for introducing a refrigerant from the supply passage to the compression chamber on the front housing side through the suction passage, and is rotatably supported by the shaft hole. A rotary valve,
A storage chamber formed between the inner peripheral surface of the front housing and the outer peripheral surface of the rotating shaft facing the inner peripheral surface;
A double-headed piston compressor provided with a shaft seal device disposed in the housing chamber for preventing refrigerant leakage along the rotating shaft,
When the imaginary line that bisects the opening width of the introduction passage to the rotation direction leading side and the rotation direction trailing side of the rotation shaft in the introduction passage is a bisector,
On the outer peripheral surface of the rotary valve,
A first communication groove having one end communicating with a region on the rotational direction leading side in the introduction passage and the other end communicating with the storage chamber;
A double-headed piston compressor in which a second communication groove having one end communicating with a region on the downstream side in the rotation direction in the introduction passage and the other end communicating with the storage chamber is formed.   The first communication groove is formed so that the one end is connected to a communication start timing portion to the suction passage in the introduction passage, and the second communication groove is connected to the suction passage in the introduction passage at the one end. The double-headed piston type compressor according to claim 1, wherein the double-headed piston compressor is formed so as to be connected to the timing unit.   The first communication groove and the second communication groove are formed such that a distance between the first communication groove and the second communication groove increases along the axial direction of the rotation shaft from the one end to the other end. The double-headed piston type compressor according to claim 1 or 2.   In the introduction passage, a part of the region near the front housing along the axial direction of the rotation shaft is opposed to the inner peripheral surface of the shaft hole, and the inner periphery of the shaft hole has the portion in the introduction passage. The double-headed piston type compressor according to any one of claims 1 to 3, wherein a collision portion that causes the refrigerant to collide is formed at a portion facing a partial region near the front housing.

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