Variable displacement compressor

Abstract

A variable displacement compressor has a housing, a piston, a drive shaft, a rotor, a cam plate and a hinge mechanism. The hinge mechanism between the rotor and the cam plate guides the cam plate to incline and slide relative to the drive shaft. Thus, the displacement volume of the compressor is varied. The rotation of the drive shaft is converted to the reciprocation of the piston through the rotor, the hinge mechanism and the cam plate. The hinge mechanism includes first and second hinge elements that are respectively provided on the rotor and on the cam plate and engage each other. At least one of the first and second hinge elements has a degree of freedom for motion against the rotor and/or the cam plate to which it belongs.

What is claimed is:  
     
         1 . A variable displacement compressor comprising: 
 a housing defining a cylinder bore;    a piston accommodated in the cylinder bore;    a drive shaft rotatably supported by the housing;    a rotor connected to the drive shaft so as to rotate integrally with;    a cam plate supported by the drive shaft so as to incline and slide relative to the drive shaft, the cam plate being operatively connected to the piston; and    a hinge mechanism interposed between the rotor and the cam plate, the hinge mechanism guiding the cam plate to incline and slide relative to the drive shaft, whereby the displacement volume of the compressor is varied, the rotation of the drive shaft being converted to the reciprocation of the piston through the rotor, the hinge mechanism and the cam plate, the hinge mechanism including: 
 a first hinge element provided on the rotor; and  
 a second hinge element provided on the cam plate, the second hinge element being engaged with the first hinge element, at least one of the first and second hinge elements having a degree of freedom for motion against the rotor and/or the cam plate to which the hinge element having the degree of freedom for motion belongs.  
   
     
     
         2 . The variable displacement compressor according to  claim 1 , wherein at least one of the first and second hinge elements has the degree of freedom for rotation in such a manner that the hinge element is pivotally supported by the rotor and/or the cam plate to which the hinge element having the degree of freedom for rotation belongs.  
     
     
         3 . The variable displacement compressor according to  claim 1 , wherein at least one of the rotor and the cam plate that includes the hinge element having the degree of freedom for motion has a regulating means for contacting to regulate a motion range of the hinge element.  
     
     
         4 . The variable displacement compressor according to  claim 1 , wherein the first hinge element has a first protrusion arranged on the rotor, the first protrusion extending toward the cam plate, the second hinge element having a second protrusion arranged on the cam plate, the second protrusion extending toward the rotor and receiving rotational power from the rotor by engagedly contacting the first protrusion, one of the first and second hinge elements including a receiving portion for receiving axial load at its proximal portion of the protrusion, the receiving portion receiving axial load that acts on the cam plate in such a manner that the receiving portion slidably contacts a distal end of the protrusion of the other of the first and second hinge elements.  
     
     
         5 . The variable displacement compressor according to  claim 4 , wherein the hinge mechanism further includes a slider that is interposed between the receiving portion and the distal end of the protrusion of the other of the first and second hinge elements.  
     
     
         6 . The variable displacement compressor according to  claim 4 , wherein the hinge mechanism further includes a pin that is connected to one of the first and second hinge elements, the other of the first and second hinge elements including a cam groove, the pin being inserted through the cam groove.  
     
     
         7 . The variable displacement compressor according to  claim 4 , wherein at least one of the first and second protrusions is plurally provided, the plurally provided protrusions being integrated with each other, the integrated plurally provided protrusions has the degree of freedom for motion against the rotor and/or the cam plate to which the integrated plurally provided protrusions belongs.  
     
     
         8 . The variable displacement compressor according to  claim 7 , wherein the number of plurally provided protrusions is two.  
     
     
         9 . The variable displacement compressor according to  claim 8 , wherein the drive shaft is rotated in a predetermined direction, the two provided protrusions being disposed in the predetermined direction, one of the provided protrusions on a preceding side in the predetermined direction being formed thicker than the other of the provided protrusions on a following side in the predetermined direction.  
     
     
         10 . The variable displacement compressor according to  claim 7 , wherein both the first and second protrusions are plurally provided, each number of the plurally provided protrusions being respectively two.  
     
     
         11 . The variable displacement compressor according to  claim 7 , wherein at least one of the first and second hinge elements includes: 
 a base having two surfaces;    a plurality of the protrusions extending from one of the surfaces of the base; and    a shaft formed on the other of the surfaces of the base.    
     
     
         12 . The variable displacement compressor according to  claim 1 , wherein the hinge element having the degree of freedom for motion is made of a material that is smaller in relative density than the rotor and/or the cam plate to which the hinge element belongs.  
     
     
         13 . The variable displacement compressor according to  claim 12 , wherein the hinge element having the degree of freedom for motion is made of aluminum series metal, while the rotor and/or the cam plate to which the hinge element belongs is made of iron series metal.  
     
     
         14 . The variable displacement compressor according to  claim 1 , wherein one of the first and second hinge elements includes a guide protrusion while the other of the first and second hinge elements includes a guide groove, the guide protrusion engaging the guide groove for guiding the cam plate to incline and slide relative to the drive shaft.  
     
     
         15 . The variable displacement compressor according to  claim 1 , wherein the cam plate is formed by forging.  
     
     
         16 . The variable displacement compressor according to  claim 1 , wherein at least one of the first and second hinge elements is made of iron series sintered metal.  
     
     
         17 . The variable displacement compressor according to  claim 1 , wherein the compressor is a piston type.  
     
     
         18 . A hinge element for partially forming a hinge mechanism of a variable displacement compressor, comprising: 
 a base having two surfaces;    a plurality of protrusions extending from one of the surfaces of the base; and    a shaft formed on the other of the surfaces of the base.