Swash plate type variable displacement compressor

Abstract

A compressor according to the present invention has a housing including a first and second cylinder bores. The inner diameter of the first cylinder bore is smaller than that of the second cylinder bore. In suction process, refrigerant gas is directly drawn from an inlet port into a first suction chamber. The refrigerant gas is flowed from the first suction chamber into a first compression chamber. In contrast, refrigerant gas is drawn through the inlet port, a first suction passage, the first suction chamber, a first communication passage, a swash plate chamber and a second communication passage and into a second compression chamber. According to the above-described compressor, wherein the inner diameter of the first cylinder bore is smaller than the second cylinder bore, the difference of the amplitude of the intake pulsation between the first compression chamber and the second compression chamber can be suitably reduced.

What is claimed is: 
     
         1 . A swash plate type variable displacement compressor comprising:
 a housing having therein a suction chamber into which refrigerant gas is drawn through an inlet port, a discharge chamber, a swash plate chamber and a cylinder bore;   a drive shaft rotatably supported by the housing;   a swash plate which is rotatable by the rotation of the drive shaft in the swash plate chamber;   a link mechanism provided between the drive shaft and the swash plate and allowing the swash plate to change the inclination angle thereof with respect to the direction perpendicular to the axis of rotation of the drive shaft;   a piston received to reciprocate in the cylinder bore;   a conversion mechanism converting rotation of the swash plate into reciprocating movement of the piston in the cylinder bore for a stroke length that is determined by the inclination angle of the swash plate;   a actuator allowing the swash plate to change the inclination angle of the swash plate; and   a control mechanism controlling the actuator,   wherein the cylinder bore includes a first cylinder bore provided on one side of the swash plate and a second cylinder bore on the other side of the swash plate, wherein the piston includes a first head that reciprocates in the first cylinder bore and forms a first compression chamber in the first cylinder bore and a second head that reciprocates in the second cylinder bore and forms a second compression chamber in the second cylinder bore, wherein the link mechanism is configured so that the top dead center position of the first head moves for a longer distance according to the change of the inclination angle of the swash plate than that of the second head, wherein the actuator includes an actuator body that is connected to the swash plate and partially movable in the direction of the axis of rotation of the drive shaft and a pressure control chamber that moves a part of the actuator body by the pressure in the pressure control chamber that is variable by the control mechanism, wherein the swash plate type variable displacement compressor further includes,   a first suction flow passage through which the refrigerant gas drawn through the inlet port flows into the first compression chamber;   a second suction flow passage through which the refrigerant gas drawn through the inlet port flows into the second compression chamber;   a first suction valve mechanism provided in the first suction flow passage; and   a second suction valve mechanism provided in the second suction flow passage, wherein the inner diameter of the first cylinder bore is smaller than that of the second cylinder bore, wherein the compressor has at least either a structure in which the first suction flow passage is different from the second suction flow passage and a structure in which the first suction valve mechanism is different from the second suction valve mechanism so that the refrigerant is drawn easily through the inlet port into the first compression chamber as compared to the case that the refrigerant gas is drawn through the inlet port into the second compression chamber.   
     
     
         2 . The swash plate type variable displacement compressor according to  claim 1 , wherein the suction chamber further includes:
 a first suction chamber provided adjacent to the first compression chamber; and   a second suction chamber provided adjacent to the second compression chamber, wherein the first suction flow passage has a first suction passage through which the inlet port is in communication with the first suction chamber, wherein the second suction flow passage has the first suction passage, the first suction chamber, the swash plate chamber, a first communication passage through which the first suction chamber and the swash plate chamber are in communication with each other and a second communication passage through which the swash plate chamber and the second suction chamber are in communication with each other.   
     
     
         3 . The swash plate type variable displacement compressor according to  claim 2 , wherein the actuator is mounted on the drive shaft in the swash plate chamber to be rotatable together with the drive shaft, wherein the actuator body includes a fixed member fixed on the drive shaft and a movable member that extends in the direction of the axis of rotation of the drive shaft, has a cylindrical shape, is connected to the swash plate, encloses the fixed member and is movable in the direction of the axis of rotation of the drive shaft, wherein the pressure control chamber is formed between the fixed member and the movable member and separated from the swash plate chamber, wherein the pressure control chamber moves the movable member so that the swash plate increases its inclination angle with an increase of the volume of the pressure control chamber. 
     
     
         4 . The swash plate type variable displacement compressor according to  claim 1 , wherein the suction chamber includes:
 a first suction chamber provided adjacent to the first compression chamber; and   a second suction chamber provided adjacent to the second compression chamber, wherein the first suction flow passage is formed in the housing and has a first suction hole through which the first compression chamber is in communication with the first suction chamber, wherein the second suction flow passage is formed in the housing and has a second suction hole through which the second compression chamber is in communication with the second suction chamber, wherein the first suction valve mechanism has a first suction reed valve that opens and closes the first suction hole according to the pressure difference between the first compression chamber and the first suction chamber, wherein the second suction valve mechanism has a second suction reed valve that opens and closes the second suction hole according to the pressure difference between the second compression chamber and the second suction chamber, wherein the first suction hole and the second suction hole are formed to have the same opening area, wherein the first suction reed valve is thinner than the second suction reed valve.   
     
     
         5 . The swash plate type variable displacement compressor according to  claim 1 , wherein the suction chamber includes:
 a first suction chamber provided adjacent to the first compression chamber; and   a second suction chamber provided adjacent to the second compression chamber, wherein the first suction flow passage is formed in the housing and has a first suction hole through which the first compression chamber is in communication with the first suction chamber, wherein the second suction flow passage is formed in the housing and has a second suction hole through which the second compression chamber is in communication with the second suction chamber, wherein the first suction valve mechanism has a first suction reed valve that opens and closes the first suction hole according to the pressure difference between the first compression chamber and the first suction chamber, wherein the second suction valve mechanism has a second suction reed valve that opens and closes the second suction hole according to the pressure difference between the second compression chamber and the second suction chamber, wherein the first suction reed valve and the second suction reed valve are formed to have the same thickness, wherein the inner diameter of the first suction hole is larger than that of the second suction hole.   
     
     
         6 . The swash plate type variable displacement compressor according to  claim 1 , wherein the suction chamber includes:
 a first suction chamber provided adjacent to the first compression chamber; and   a second suction chamber provided adjacent to the second compression chamber, wherein the first suction flow passage is formed in the housing and has a first suction hole through which the first compression chamber is in communication with the first suction chamber, wherein the second suction flow passage is formed in the housing and has a second suction hole through which the second compression chamber is in communication with the second suction chamber, wherein the first suction valve mechanism has a first suction reed valve that opens and closes the first suction hole according to the pressure difference between the first compression chamber and the first suction chamber, wherein the second suction valve mechanism has a second suction reed valve that opens and closes the second suction hole according to the pressure difference between the second compression chamber and the second suction chamber, wherein the first suction hole and the second suction hole are formed to have the same opening area, wherein the first suction reed valve and the second suction reed valve are formed to have the same thickness, wherein the first suction reed valve is bent larger than the second suction reed valve.   
     
     
         7 . The swash plate type variable displacement compressor according to  claim 1 , wherein the inner diameter of the first suction flow passage is larger than that of the second suction flow passage. 
     
     
         8 . The swash plate type variable displacement compressor according to  claim 1 , wherein the overall length of the first suction flow passage is shorter than that of the second suction flow passage. 
     
     
         9 . The swash plate type variable displacement compressor according to  claim 1 , wherein the suction chamber includes:
 a first suction chamber provided adjacent to the first compression chamber; and   a second suction chamber provided adjacent to the second compression chamber, wherein the first suction flow passage is formed in the housing and has a first suction hole through which the first compression chamber is in communication with the first suction chamber, wherein the second suction flow passage is formed in the housing and has a second suction hole through which the second compression chamber is in communication with the second suction chamber, wherein the first suction valve mechanism has a rotating valve through which the first compression chamber in suction process is in communication with the first suction chamber with the rotation of the drive shaft, wherein the second suction valve mechanism has a suction reed valve that opens and closes the second suction hole according to the pressure difference between the second compression chamber and the second suction chamber.