Swash plate-type variable displacement compressors

Abstract

A swash plate-type, variable displacement compressor includes a front housing, a cylinder block, a rear housing, and a drive shaft rotatably supported by the front housing and by the cylinder block. The compressor also includes a rotor fixed to the drive shaft, such that the rotor and the drive shaft rotate together, and a plurality of pistons, each of which is slidably positioned within a corresponding cylinder bore. The compressor further includes a swash plate having a penetration hole formed through a center portion of the swash plate. Moreover, the drive shaft extends through the penetration hole and the swash plate is connected to the pistons via a pair of shoes. The compressor also includes a hinge mechanism which connects the rotor to the swash plate. The hinge mechanism includes a single rotor arm having an oblong hole formed therethrough, and a single swash plate arm having a pin portion extending therefrom, such that the pin portion slidably engages an inner wall of the oblong hole. When a mechanical load of the compressor is greater than a predetermined mechanical load, a resultant force of the mechanical load is located at a point along a first portion of a force line, and an area of engagement between a surface of the pin portion and the inner wall of the oblong hole includes the first portion of the force line.

What is claimed is:  
     
         1 . A swash plate-type, variable displacement compressor comprising: 
 a front housing;    a cylinder block, wherein a plurality of cylinder bores are formed within said cylinder block;    a rear housing;    a drive shaft rotatably supported by said front housing and by said cylinder block;    a rotor fixed to said drive shaft, such that said rotor and said drive shaft rotate together;    a plurality of pistons, each of which is slidably positioned within a corresponding cylinder bore;    a swash plate having a penetration hole formed through a center portion of said swash plate, wherein said drive shaft extends through said penetration hole and said swash plate is connected to each of said pistons by a pair of shoes; and    a hinge mechanism connecting said rotor to said swash plate, such that a tilt angle of said swash plate varies with respect to an axis of rotation of said drive shaft, wherein said hinge mechanism comprises: 
 a single rotor arm having an oblong hole formed therethrough; and  
 a single swash plate arm having a pin portion extending therefrom, wherein said pin portion slidably engages an inner wall of said oblong hole, and when a mechanical load of said compressor is greater than a predetermined mechanical load, a resultant force of said mechanical load is located at a point along a first portion of a force line, wherein an area of engagement between a surface of said pin portion and said inner wall of said oblong hole comprises said first portion of said force line.  
   
     
     
         2 . The compressor of  claim 1 , wherein when a mechanical load of said compressor is less than said predetermined mechanical load, said resultant force of said mechanical load is located at a point along a second portion of said force line.  
     
     
         3 . The compressor of  claim 2 , wherein said second portion of said force line is substantially outside said area of engagement between said surface of said pin portion and said inner wall of said oblong hole.  
     
     
         4 . The compressor of  claim 2 , wherein said second portion of said force line is entirely outside said area of engagement between said surface of said pin portion and said inner wall of said oblong hole.