Variable displacement compressor

Abstract

A variable displacement compressor including a hinge mechanism that is easily machined. The hinge mechanism is arranged in the compressor between the lug plate and the cam plate. The hinge mechanism includes a support formed on the cam plate. A spherical projection extends from the support in a direction rearward with respect to the direction a drive shaft rotates. A roller extends from the support in a direction forward with respect to the direction the drive shaft rotates. A first cam is formed on the lug plate surrounding and guiding the spherical portion. A second cam is formed on the lug plate. The second cam includes a cam surface that contacts and guides the roller.

1 . A compressor that transmits rotation of a drive shaft from a lug plate to a cam plate, reciprocates a piston as the cam plate rotates to compress gas, and alters an inclination angle of the cam plate to vary displacement, the compressor comprising: 
 a hinge mechanism arranged between the lug plate and the cam plate, wherein the hinge mechanism includes; 
 a support formed on the cam plate;  
 a first guide projection extending from the support in a direction rearward with respect to the direction the drive shaft rotates;  
 a second guide projection extending from the support in a direction forward with respect to the direction the drive shaft rotates;  
 a first cam, formed on the lug plate in a manner surrounding the first guide projection, for guiding the first guide projection; and  
 a second cam formed on the lug plate and including a cam surface for contacting and guiding the second guide projection.  
   
   
   
       2 . The compressor according to  claim 1 , wherein the second cam includes a front opposing the rotational direction of the drive shaft in which the front is open.  
   
   
       3 . The compressor according to  claim 1 , wherein the piston is moved to a top dead center position, the cam plate includes a portion located between the first guide projection and the second guide projection for moving the piston to the top dead center position of the piston, and the distance between the second projection and the portion is greater than the distance between the first guide projection and the portion.  
   
   
       4 . The compressor according to  claim 1 , wherein the hinge mechanism further includes: 
 a pin portion extending from the support along the axis intersecting the drive shaft, in which the second guide projection includes a roller supported by the pin portion in a rotatable manner.    
   
   
       5 . The compressor according to  claim 4 , wherein the support includes an insertion hole, and the hinge mechanism includes a pin inserted through the insertion hole of the support, the pin having a first end portion with a spherical portion defining the first guide and a second end portion defining the pin portion, wherein the spherical portion has a diameter that is smaller than that of the insertion hole.  
   
   
       6 . The compressor according to  claim 5 , wherein the spherical portion is formed integrally with the pin.  
   
   
       7 . The compressor according to  claim 5 , wherein the pin includes a stopper, integrally formed with the second end portion, for preventing the roller from falling off the pin.  
   
   
       8 . The compressor according to  claim 4 , wherein the pin portion extends out of the roller.  
   
   
       9 . The compressor according to  claim 1 , wherein the distance between the second guide projection and the support is less than the distance between the first guide projection and the support.  
   
   
       10 . The compressor according to  claim 1 , wherein the compressor compresses carbon dioxide refrigerant gas for an air conditioner.  
   
   
       11 . The compressor according to  claim 1 , wherein the first cam includes a groove for guiding the first guide projection.  
   
   
       12 . The compressor according to  claim 1 , wherein the first cam includes an elongated hole for guiding the first guide projection.  
   
   
       13 . The compressor according to  claim 1 , wherein the first guide projection extends from the support rearward from the second guide projection with respect to the rotational direction of the drive shaft.  
   
   
       14 . A compressor comprising: 
 a housing;    a cylinder bore formed in the housing;    a drive shaft supported in the housing in a rotatable manner;    a lug plate connected to the drive shaft to rotate integrally with the drive shaft;    a cam plate supported by the drive shaft in an inclinable manner, the cam plate having a first surface facing towards the lug plate, and the lug plate having a second surface facing towards the first surface of the cam plate;    a piston having an end connected to the cam plate and reciprocated in the cylinder bore; and    a hinge mechanism arranged between the lug plate and the cam plate;    wherein the hinge mechanism includes: 
 a support formed on the first surface;  
 a first guide projection extending from the support in a direction rearward with respect to the direction the drive shaft rotates;  
 a second guide projection extending from the support in a direction forward with respect to the direction the drive shaft rotates;  
 a first cam, formed on the second surface in a manner surrounding the first guide projection, for guiding the first guide projection; and  
 a second cam formed on the second surface and including a cam surface for contacting and guiding the second guide projection.  
   
   
   
       15 . A compressor comprising: 
 a housing;    a cylinder bore formed in the housing;    a drive shaft supported in the housing in a rotatable manner;    a lug plate connected to the drive shaft to rotate integrally with the drive shaft;    a cam plate supported by the drive shaft in an inclinable manner, the cam plate having a first surface facing towards the lug plate, and the lug plate having a second surface facing towards the first surface of the cam plate;    a piston having an end connected to the cam plate and reciprocated in the cylinder bore; and    a hinge mechanism arranged between the lug plate and the cam plate;    wherein the hinge mechanism includes: 
 a support formed on the first surface and including an insertion hole;  
 a pin inserted through the insertion hole and having a spherical portion and a rotatable roller, the spherical portion extending from the support in a direction rearward with respect to the direction the drive shaft rotates, and the roller extending from the support in a direction forward with respect to the direction the drive shaft rotates;  
 a first cam formed on the second surface and including a groove surrounding and guiding the spherical portion; and  
 a second cam formed on the second surface and including a cam surface for contacting and guiding the roller.  
   
   
   
       16 . The compressor according to  claim 15 , wherein the groove and the cam surface are sloped so that the second surface becomes farther as the drive shaft becomes closer.