Swash plate type compressor

Abstract

A swash plate type compressor has a housing assembly, a drive shaft, a swash plate, a piston, a motion converter, a bleed passage, and an oil separator. The housing assembly includes a cylinder bore, a suction chamber, a discharge chamber, and a crank chamber. The drive shaft is rotatably supported by the housing assembly, and extends through the crank chamber. The bleed passage communicates between the crank chamber and the suction chamber. The oil separator is disposed in the housing assembly. The oil separator separates no or less amount of lubricating oil from the refrigerant gas in the increased rotational speed of the drive shaft than that in the decreased rotational speed of the drive shaft. The refrigerant gas passed through the oil separator is introduced into the suction chamber, and the separated lubricating oil is returned to the crank chamber.

1 . A swash plate type compressor comprising:
 a housing assembly including a cylinder bore, a suction chamber, a discharge chamber, and a crank chamber;   a drive shaft rotatably supported by the housing assembly, the drive shaft extending through the crank chamber;   a swash plate supported by the drive shaft in the crank chamber;   a piston accommodated in the cylinder bore so as to be reciprocally slidable therein;   a motion converter disposed between the swash plate and the piston, the motion converter converting wobbling motion of the swash plate into reciprocating motion of the piston;   a bleed passage for communicating between the crank chamber and the suction chamber; and   an oil separator disposed in the housing assembly, wherein the oil separator separates no or less amount of lubricating oil from the refrigerant gas in the increased rotational speed of the drive shaft than that in the decreased rotational speed of the drive shaft, the refrigerant gas passed through the oil separator is introduced into the suction chamber, and the separated lubricating oil is returned to the crank chamber.   
   
   
       2 . The swash plate type compressor according to  claim 1 , wherein the bleed passage includes an upstream passage in communication with a region containing a relatively large amount of lubricating oil in the crank chamber, wherein the oil separator separates lubricating oil from refrigerant gas in the upstream passage. 
   
   
       3 . The swash plate type compressor according to  claim 2 , wherein the housing assembly further having a valve unit having a throttle hole which is connected to the suction chamber, wherein the oil separator has an accommodation chamber being in communication with the suction chamber through the throttle hole, wherein one end of the drive shaft is located in the accommodation chamber, an oil separating member disposed in the accommodation chamber and partitioning into the first chamber in indirect communication with the throttle hole and a second chamber in direct communication with the throttle hole with a clearance therebetween so as to separate lubricating oil from refrigerant gas by introducing the refrigerant gas from the first chamber to the second chamber through the clearance, and the separated lubricating oil is retained in the first chamber, a return passage for connecting the first chamber to the crank chamber, and a valve for connecting the upstream passage to the second chamber due to the increased rotational speed of the drive shaft and disconnecting the upstream passage to the second chamber due to the decreased rotational speed of the drive shaft, wherein the bleed passage has a discharge hole for communicating with the upstream passage and the first chamber. 
   
   
       4 . The swash plate type compressor according to  claim 3 , wherein the valve has an opening for passing through the refrigerant gas, and the cross-section of the opening of the valve is larger than either the cross-section of the clearance or the cross-section of the discharge hole. 
   
   
       5 . The swash plate type compressor according to  claim 3 , wherein the return passage is in communication with a region containing a relatively small amount of lubricating oil in the crank chamber. 
   
   
       6 . The swash plate type compressor according to  claim 3 , wherein the return passage connects the lower region of the first chamber to the crank chamber with the compressor installed in a vehicle. 
   
   
       7 . The swash plate type compressor according to  claim 3 , wherein the valve is operated by centrifugal force. 
   
   
       8 . The swash plate type compressor according to  claim 7 , wherein the valve is fixed to the rear end of the drive shaft, and formed with a cylindrical shape having a spherical cap shaped end which is divided into plural segments to the radial direction, and the plural segments move to the radial direction by the centrifugal force against its own elastic force so as to open the valve. 
   
   
       9 . The swash plate type compressor according to  claim 7 , wherein the drive shaft includes a valve hole and a guide hole formed in parallel with the discharge hole so as to extend in the radial direction of the drive shaft and connect to the upstream passage, wherein the valve includes a valve body received slidably in the valve hole and being movable into the upstream passage so as to close the upstream passage, a connecting bar received in the guide hole and one end of which is fixed to the valve body, a spring seat fixed to the other end of the connecting bar, and a spring disposed between the outer peripheral surface of the drive shaft and the spring seat for urging the valve body in the direction that closes the upstream passage. 
   
   
       10 . The swash plate type compressor according to  claim 7 , wherein the drive shaft includes a valve hole formed in the bleed passage for communicating with the upstream passage and the second chamber, and a guide hole formed coaxially with the valve hole in parallel with the discharge hole so as to extend in the radial direction of the drive shaft, and having a smaller cross-section than the valve hole, wherein the valve includes a valve body movably disposed on the outer end of the valve hole so as to close the valve hole, a connecting bar slidably inserted through the guide hole and the valve hole and one end of which is fixed to the valve body, a spring seat fixed to the other end of the connecting bar, and a spring disposed between the outer peripheral surface of the drive shaft and the spring seat for urging the valve body against the outer peripheral surface of the drive shaft to close the valve hole. 
   
   
       11 . The swash plate type compressor according to  claim 7 , wherein an assembly is fitted on the rear end of the drive shaft, and includes a rear passage formed through the assembly to form a part of the upstream passage, a first valve hole and a second valve hole extending in the radial direction of the assembly and connected to the rear passage respectively, a valve seat formed at the end of the first valve hole and forming the discharge hole with the first valve hole, wherein the valve having:
 a first valve body;   a second valve body slidably received in the second valve hole, the second valve body being movable into the rear passage so as to close the upstream passage;   a connecting bar one end of which is fixed to the first valve body, and the other end of which is fixed to the second valve body;   a spring seat disposed between the first valve hole and the second valve hole; and   a spring disposed between the first valve body and the spring seat for urging the first valve body in the direction that disengages from the valve seat for opening the discharge hole, and the second valve body in the direction that closes the upstream passage.   
   
   
       12 . The swash plate type compressor according to  claim 2 , wherein the swash plate is supported so as to be tiltable, wherein a lug plate is fixed to the drive shaft for rotation therewith, wherein the upstream passage includes an oil guide passage extending from the outer region of the crank chamber to a space between the housing assembly and the lug plate. 
   
   
       13 . The swash plate type compressor according to  claim 12 , wherein the shaft seal is arranged between the housing assembly and the drive shaft for sealing the drive shaft, wherein the upstream passage communicates with the shaft seal adjacent to the oil guide passage.