JP2008057336A - Variable displacement compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To recirculate the refrigerant gas in a crankcase into a suction chamber according to the pressure in the crankcase on the rear end side of a drive shaft while restraining the movement of the drive shaft to the rear end side without installing a dedicated pressurizing spring for pressing the rear end of the drive shaft forward. <P>SOLUTION: A collar 47 fitted to the rear end of a drive shaft 23 comprises a flange part 47a with which a return spring 45 installed between itself and a swash plate 31 is brought into contact and a cylindrical part 47b into which the drive shaft 23 is inserted. A projection 47c on the inner surface of the cylindrical part 47b is fitted into the recess 23a of the drive shaft 23. A sliding bearing 19 rotatably supporting the rear end part of the drive shaft 23 comprises a bearing flange part 19a supporting a thrust load and a bearing cylindrical part 19b supporting a radial load. A groove 47d forming a part of an air bleed passage 51 allowing a crankcase 5 to communicate with a suction chamber 11 is formed in the flange part 47a of the collar 47 opposed to the bearing flange part 19a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a variable capacity compressor in which a stroke of a piston is changed by changing an inclination angle of a swash plate in accordance with a pressure in a crank chamber.

  An example of a conventional variable capacity compressor is described in Patent Document 1 below. This variable capacity compressor is provided with a swash plate that is axially movable and rotatable with the drive shaft on the outer periphery of the drive shaft, and the inclination angle of the swash plate changes depending on the pressure in the crank chamber, and the change of the inclination angle As a result, the stroke of the piston provided on the outer peripheral side of the swash plate changes, and the discharge capacity of the refrigerant changes.

  Also, return springs are provided on both axial sides of the drive shaft of the swash plate to press the swash plate in the axial direction, and the swash plate is in a predetermined position (close to a right angle with respect to the drive shaft) while the compressor is stopped. ) To hold. Of the return springs provided on both sides in the axial direction, the return spring provided on the rear end side of the drive shaft is fixed to the receiving plate whose end opposite to the swash plate is rotatably contacted with the end face of the cylinder block. The return spring and the receiving plate rotate in synchronization with the rotation of the drive shaft and the swash plate.

Furthermore, a thrust trace and a pressure spring are provided at the end on the rear end side of the drive shaft, and the drive shaft is pressed forward. By pressing the drive shaft forward, the top of the piston attached to the outer peripheral side of the swash plate can be prevented from interfering with the valve plate provided at the top dead center end in the cylinder bore. .
JP 2001-295757 A

  As described above, in the conventional variable capacity compressor described above, the dedicated pressure spring for pressing the rear end side of the drive shaft forward and restricting the position in the axial direction is provided. Improvements are desired.

  In the variable capacity compressor, as described above, the inclination angle of the swash plate changes depending on the pressure in the crank chamber, and the piston stroke changes due to the change in the inclination angle, so that the refrigerant discharge capacity changes. The extraction passage for returning the refrigerant gas in the crank chamber to the suction chamber in accordance with the pressure in the crank chamber is not particularly considered.

  Therefore, the present invention restricts the movement of the drive shaft to the rear end portion side without providing a dedicated pressure spring for pressing the rear end portion of the drive shaft forward, and the rear end side of the drive shaft. It is an object of the present invention to allow the refrigerant gas in the crank chamber to be returned to the suction chamber in accordance with the pressure in the crank chamber.

  The present invention relates to a swash plate that can be tilted according to the pressure in the crank chamber, and connected to the swash plate and reciprocatingly moves in a cylinder bore to suck low-pressure refrigerant gas from the suction chamber and discharge high-pressure refrigerant gas to the discharge chamber. A piston that discharges to the housing, and a rear end portion that is rotatably supported by the housing having the cylinder bore, communicates the drive shaft that rotationally drives the swash plate, the crank chamber, and the suction chamber. A bleed passage for returning the refrigerant gas in the crank chamber to the suction chamber according to the pressure in the chamber, and the stroke of the piston is changed by changing the inclination angle of the swash plate according to the pressure in the crank chamber. In the variable capacity compressor, the return spring for pressing the swash plate toward the front end of the drive shaft is provided, and the return spring is opposed to the axially opposed surface of the housing. A receiving member that receives the end of the return spring opposite to the swash plate, and the receiving member rotates relative to the drive shaft of the receiving member and the housing of the drive shaft with respect to the housing. And a regulation passage that regulates movement toward the rear end, and a refrigerant passage that communicates the crank chamber with a through passage in the drive shaft that is a part of the extraction passage. Main features.

  According to the present invention, the relative rotation of the receiving member with respect to the drive shaft, and the receiving member that is in a position facing the axially opposed surface of the housing and that is in contact with the end of the return spring opposite to the swash plate, Since the restricting portions for restricting the movement of the drive shaft to the rear end side with respect to the housing are provided, the drive shaft is not provided with a dedicated pressure spring for pressing the drive shaft forward to restrict the axial position. The movement to the rear end side can be restricted. In addition, the receiving member is provided with a refrigerant passage portion that communicates the crank chamber with a through-passage in the drive shaft that is a part of the extraction passage, so that the pressure on the rear end portion of the drive shaft corresponds to the pressure in the crank chamber. Thus, the refrigerant gas in the crank chamber can be returned to the suction chamber.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view of a variable capacity compressor showing an embodiment of the present invention, and this variable capacity compressor is used for a refrigeration cycle of a vehicle air conditioner mounted on a vehicle such as an automobile. This is a swash plate type variable capacity compressor.

  This swash plate type variable capacity compressor is joined to a cylinder block 3 having a plurality of cylinder bores 1 and a front end face on the left side of the cylinder block 3 in FIG. 1 to form a crank chamber 5 between the cylinder block 3. A front housing 7 and a rear housing 15 joined to the rear end surface of the cylinder block 3 via a valve plate 9 and forming a suction chamber 11 and a discharge chamber 13 are provided.

  The cylinder block 3, the front housing 7 and the rear housing 15 are fastened and fixed by through bolts 16 to constitute a housing of a variable capacity compressor.

  The valve plate 9 includes a suction hole 9 a that communicates the cylinder bore 1 and the suction chamber 11, and a discharge hole 9 b that communicates the cylinder bore 1 and the discharge chamber 13. A suction valve (not shown) for opening and closing the suction hole 9a is provided on the cylinder block 3 side of the valve plate 9, while a discharge valve (not shown) for opening and closing the discharge hole 9b is provided on the rear housing 15 side of the valve plate 9. And a retainer 17 that holds the discharge valve and restricts the opening limit of the discharge valve.

  Shaft bearings 19a and 7a are provided in the center of the cylinder block 3 and the front housing 7, respectively, and a sliding bearing 19 as a bearing for rotatably supporting the rear end portion of the drive shaft 23 in the shaft supporting holes 3a and 7a. And the radial bearing 21 which supports the front-end part of the drive shaft 23 rotatably is provided. The sliding bearing 19 will be described in detail later.

  In the crank chamber 5, a drive plate 25 that is press-fitted and fixed to the drive shaft 23 from the outside, a sleeve 27 that is slidably fitted in the drive shaft 23 in the axial direction, and a sleeve 27 that is swingable. And a swash plate 31 fixed to a boss portion 29 a of the journal 29. A thrust bearing 30 is provided between the front end surface of the drive plate 25 and the inner wall surface of the front housing 7.

  The drive plate 25 and the journal 29 have their hinge arms 25h and 29h connected via a link 33 and pins 35 and 37, thereby transmitting the rotational force of the drive plate 25 to the journal 29 while the journal 29 The inclination of the (swash plate 31) is allowed. The piston 39 accommodated in each cylinder bore 1 is connected to the swash plate 31 via a pair of shoes 41 sandwiching the swash plate 31, and reciprocates using the rotational motion of the drive shaft 23 as a driving force.

  The drive shafts 23 on both axial sides of the swash plate 31 are provided with return springs 43 and 45 to press the swash plate 31 in the axial direction so that the swash plate 31 is moved to a predetermined position while the variable capacity compressor is stopped. (The swash plate 31 is held at a right angle to the drive shaft 23). Among these, the return spring 43 on the crank chamber 5 side is housed in a compressed state between the sleeve 27 of the swash plate 31 and the drive plate 25.

  On the other hand, the return spring 45 on the cylinder bore 1 side is accommodated in a compressed state between the sleeve 27 and a collar 47 as a receiving member fixed to the outer periphery of the drive shaft 23. Most of the collar 47 and the return spring 45 are accommodated in a front end side recess 49 formed in the cylinder block 3, and the front end side recess 49 communicates with the crank chamber 5.

  2, the collar 47 is located at a position facing the bottom 49a of the front end side recess 49, which is a surface facing the axial direction of the cylinder block 3 as a housing, and is located at the end of the return spring 45. And a cylindrical portion 47b that is connected to the inner peripheral end of the flange portion 47a and covers the outer peripheral surface of the drive shaft 23.

  A protrusion 47 c as a fixing part is provided on the inner peripheral surface of the cylindrical part 47 b, and the protrusion 47 c is fitted into a recess 23 a provided on the outer periphery of the drive shaft 23. The recess 23a is formed in a groove shape extending in the axial direction from the end surface on the rear end side of the drive shaft 23. When the drive shaft 23 is inserted into the collar 47 from the rear end side, the groove shape is formed. The protrusion 47c is aligned and slid to the recess 23a, and as shown in FIG. 2, the protrusion 47c is brought into contact with the restricting surface 23e at the left end of the recess 23a in FIG.

  Thus, the protrusion 47c constitutes a restricting portion that restricts the relative rotation of the collar 47 with respect to the drive shaft 23 and the movement of the drive shaft 23 to the rear end side (right side in FIG. 2) with respect to the housing 3. As the swash plate 31 is rotated by the rotation of the drive shaft 23, the return spring 45 and the collar 47 are also rotated in synchronization.

  Further, between the flange portion 47 a of the collar 47 and the bottom portion 49 a of the cylinder block 3, the bearing flange portion 19 a of the slide bearing 19 is disposed. The flange portion 47a of the collar 47 contacts the bearing flange portion 19a and receives a thrust load.

  The slide bearing 19 includes a bearing cylindrical portion 19b that is connected to the inner peripheral end of the bearing flange portion 19a and receives a radial load while contacting the outer peripheral surface of the drive shaft 23.

  Here, the basic function of this variable capacity compressor is to compress the refrigerant sucked into the cylinder bore 1 through the suction chamber 11 → the suction hole 9 a of the valve plate 9 by the reciprocating motion of the piston 39, and the cylinder bore 1 → the valve plate 9. Discharge hole 9b → discharge chamber 13 and refrigerant are discharged.

  And in order to make this discharge capacity variable, the extraction passage 51 which always connects the crank chamber 5 and the suction chamber 11, the supply passage 53 which connects the crank chamber 5 and the discharge chamber 13, and the supply passage A pressure control mechanism including pressure control means 55 for opening and closing 53 is provided.

  The extraction passage 51 described above returns the refrigerant gas in the crank chamber 5 to the suction chamber 11 in accordance with the refrigerant gas pressure in the crank chamber 5. The air supply passage 53 is opened and closed by the pressure control means 55 to control the amount of refrigerant gas flowing from the discharge chamber 13 toward the crank chamber 5, thereby adjusting the pressure in the crank chamber 5, and the inclination angle of the swash plate 31. Is changed to change the stroke of the piston 39 to change the discharge capacity of the variable capacity compressor.

  Here, on the surface of the flange portion 47a of the collar 47 that faces the bearing flange portion 19a of the slide bearing 19, a groove 47d as a refrigerant passage portion is provided. 3A and 3B show a single unit of the collar 47, where FIG. 3A is a plan view of FIG. 2, and FIG. 3B is a front view of the collar 47 as viewed from the right side in FIG. As shown particularly in FIG. 3B, the grooves 47d are provided at three locations at equal intervals in the circumferential direction, and are formed radially so as to extend in the diameter direction of the drive shaft 23.

  The groove 47d described above communicates with the through passage 23b formed in the drive shaft 23. The through passage 23b communicates with an axial passage 23c extending in the axial direction from the rear end portion of the drive shaft 23 toward the front (leftward in FIG. 2), and a tip of the axial passage 23c. A radial passage 23d that extends in the radial direction and opens in the outer peripheral surface of the drive shaft 23 and communicates with the groove 47d described above.

  The bleed passage 51 has a front end side recess 49 on the crank chamber 5 side, a groove 47d of the collar 47 communicating with the front end side recess 49, a through passage 23b in the drive shaft 23 communicating with the groove 47d, and a through hole. The rear housing 15 side rear end recess 57 formed in the cylinder block 3 and in communication with the passage 23b, the bleed groove 3s provided in the rear end surface of the cylinder block 3 and in communication with the rear end recess 57, and the bleed air A bleed hole 9 s communicated with the groove 3 s and provided in the valve plate 9, and a bleed hole 15 s communicated between the bleed hole 9 s and the suction chamber 11 and provided in the rear housing 15.

  The bleed groove 3s in this case constitutes a throttle portion (orifice) that squeezes the cross-sectional area of the bleed passage 51 in the middle of the bleed passage 51.

  According to the variable capacity compressor configured as described above, the collar 47 is configured such that the end of the return spring 45 located on the right side of the swash plate 31 on the right side in FIG. In addition to constituting a spring receiver, the protrusion 47c is fitted into the recess 23a of the drive shaft 23 so that the restricting surface 23b is in contact with the protrusion 47c, so that the movement of the drive shaft 23 toward the rear end side is restricted. Can do. At this time, without providing a dedicated pressure spring for pressing the rear end side of the drive shaft 23 forward, the rear end side in the axial direction of the drive shaft 23 by the collar 47 serving as a spring receiver of the existing return spring 45. The movement to can be regulated.

  As a result, when the variable capacity compressor is operated, the drive shaft 23 is prevented from moving rightward in FIG. 1, and the valve plate 9 provided at the top dead center side end of the top of the piston 39 is prevented. Interference can be avoided. In particular, here, a clutch mechanism 59 for cutting off the connection of external power is provided at the front end portion of the drive shaft 23 that receives rotational input, and when the clutch mechanism 59 is connected, the drive shaft 23 faces toward the rear end side. Even in this case, it is possible to prevent the piston 39 from interfering with the valve plate 9.

  Further, since the collar 47 rotates in synchronization with the rotation of the swash plate 31 and the return spring 45 accompanying the rotation of the drive shaft 23, the return spring 45 and the collar 47 do not slide with each other. Can be prevented.

  Further, the collar 47 described above includes a groove 47d serving as a refrigerant passage portion that communicates between the crank chamber 5 and the through passage 23b in the drive shaft 23 that is a part of the extraction passage 51. The bleed passage 51 that always communicates the crank chamber 5 and the suction chamber 11 can be configured with a simple structure of forming the groove 47d, whereby the inside of the crank chamber 5 is formed on the rear end side of the drive shaft 23. The refrigerant gas in the crank chamber 5 can be returned to the suction chamber 11 in accordance with the pressure.

  At this time, since the lubricating oil is also contained in the refrigerant circulated by the variable capacity compressor, the lubricating oil also flows into the extraction passage 51 described above, and the collar 47 in sliding contact with the bearing flange portion 19a of the sliding bearing 19 is provided. Lubricating oil also flows in the groove 47d provided in the flange portion 47a, so that the sliding bearing 19 can be lubricated.

  Further, since the grooves 47d are formed radially extending in the diameter direction of the drive shaft 23, the through-passage 23b in the drive shaft 23 and the front end side concave portion 49 on the crank chamber 5 side can communicate with each other at the shortest distance, and the collar Since the processed portion with respect to 47 can be minimized, the rigidity of the flange portion 47a of the collar 47 can be ensured.

  Further, the sliding bearing 19 is connected to the bearing flange portion 19 a that receives the thrust load by contacting the flange portion 47 a of the collar 47, and is in contact with the outer peripheral surface of the drive shaft 23 by being connected to the inner peripheral side end portion of the bearing flange portion 19 a. However, since the bearing cylindrical portion 19b that receives the radial load is provided, both the thrust load and the radial load of the drive shaft 23 can be received by one sliding bearing 19, which contributes to the simplification of the structure. Can do.

It is sectional drawing of the variable capacity compressor which shows one Embodiment of this invention. FIG. 2 is a cross-sectional view showing a main part around a rear end side of a drive shaft in the variable capacity compressor of FIG. FIGS. 2A and 2B show a single collar used in the variable capacity compressor of FIG. 1, wherein FIG. 2A is a plan view of FIG. 2, and FIG.

Explanation of symbols

3 Cylinder block (housing)
5 Crank chamber 11 Suction chamber 19 Sliding bearing (bearing)
19a Bearing flange portion 19b Bearing cylindrical portion 23 Drive shaft 23b Through passage in drive shaft 31 Swash plate 39 Piston 45 Return spring 47 Collar (receiving member)
47c Color projection (regulator)
47d collar groove (refrigerant passage)
49a Bottom of front end side recess (surface facing the axial direction of the housing)
51 Extraction passage

Claims (4)

  A swash plate (31) tiltable according to the pressure in the crank chamber (5), and connected to the swash plate (31) and reciprocatingly moved in the cylinder bore (1), thereby reducing the pressure from the suction chamber (11). The piston (39) for sucking the refrigerant gas and discharging the high-pressure refrigerant gas to the discharge chamber (13), and the rear end portion are rotatably supported with respect to the housing (3) having the cylinder bore (1), The drive shaft (23) for rotationally driving the swash plate (31), the crank chamber (5), and the suction chamber (11) communicate with each other, and the crank chamber (5) according to the pressure in the crank chamber (5). 5) A bleed passage (51) for returning the refrigerant gas in the interior to the suction chamber (11), and the inclination angle of the swash plate (31) changes according to the pressure in the crank chamber (5). Thus, the variable displacement pressure at which the stroke of the piston (39) changes In the machine, a return spring (45) for pressing the swash plate (31) toward the front end of the drive shaft (23) is provided, and the surface (49a) facing the axial direction of the housing (3) is opposed. A receiving member (47) is provided that receives the end of the return spring (45) opposite to the swash plate (31), and the receiving member (47) is configured to drive the receiving member (47). A restricting portion (47c) for restricting relative rotation with the shaft (23) and movement of the drive shaft (23) toward the rear end with respect to the housing (3), the crank chamber (5), and the bleed air A variable capacity compressor, comprising: a refrigerant passage portion (47d) that communicates with a through passage (23b) in a drive shaft (23) that is a part of the passage (51).   The said refrigerant | coolant channel | path part (47d) is comprised by the groove | channel (47d) provided in the surface (49a) facing the axial direction of the said housing (3), The surface (49d) is provided. Variable capacity compressor.   The variable capacity compressor according to claim 2, wherein the groove (47d) is formed in a radial shape extending in a diameter direction of the drive shaft (23).   A bearing (19) for rotatably supporting the rear end portion of the drive shaft (23) is provided between the housing (3) and the bearing (19) is in contact with the receiving member (47) to be thrust. A bearing flange portion (19a) that receives a load, and a bearing cylindrical portion (19b) that is connected to the inner peripheral side end portion of the bearing flange portion (19a) and receives a radial load while contacting the outer peripheral surface of the drive shaft (23). The variable capacity compressor according to any one of claims 1 to 3, further comprising:

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