Variable displacement compressor with single-head pistons

Abstract

The muffler has a muffler chamber formed in a rear housing, an inlet channel that provides communication between the discharge chamber and the muffler chamber, and an outlet channel that provides communication between the muffler chamber and the outlet port. The muffler chamber has a first end surface positioned on one end side of the muffler chamber, a second end surface positioned on the other end side of the muffler chamber, and an inner peripheral surface having a cylindrical shape that is positioned between the first end surface and the second end surface and extends from the discharge chamber toward the other end side. The muffler chamber is positioned between an annular wall and an outer peripheral wall. The inlet channel opens in the first end surface. The outlet channel opens in the inner peripheral surface at a position spaced apart from the second end surface.

1 . A variable displacement compressor with single-head pistons, comprising:
 a cylinder block having a plurality of cylinder bores that are formed side by side in a circumferential direction and extend in parallel with each other in an axial direction;   a front housing that is fixed to one end side of the cylinder block in the axial direction and has a crank chamber formed therein;   a rear housing that is fixed to the other end side of the cylinder block in the axial direction and has a suction chamber and a discharge chamber formed therein;   a plurality of pistons each housed in each of the cylinder bores so as to reciprocate and defining a compression chamber in each of the cylinder bores on the other end side; and   driving means that is provided in the crank chamber and is capable of making each of the pistons reciprocate and changing strokes of each of the pistons,   the rear housing having an annular wall that separates the suction chamber and the discharge chamber from each other,   the discharge chamber being formed between the annular wall and an outer peripheral wall of the rear housing so as to extend in the circumferential direction and annularly surround the suction chamber,   an outlet port, through which the discharge chamber is in communication with the outside, being formed in the cylinder block or the rear housing,   a muffler being provided between the discharge chamber and the outlet port,   the muffler having a muffler chamber, an inlet channel and an outlet channel, and   the muffler chamber being formed in the rear housing, the inlet channel providing communication between the discharge chamber and the muffler chamber, and the outlet channel providing communication between the muffler chamber and the outlet port,   wherein the muffler chamber has:   a first end surface positioned on the one end side of the muffler chamber;   a second end surface positioned on the other end side of the muffler chamber; and   an inner peripheral surface having a cylindrical shape that is positioned between the first end surface and the second end surface and extends from the discharge chamber toward the other end side,   the muffler chamber is positioned between the annular wall and the outer peripheral wall,   the inlet channel opens in the first end surface, and   the outlet channel opens in the inner peripheral surface at a position spaced apart from the second end surface.   
     
     
         2 . The variable displacement compressor with single-head pistons according to  claim 1 , wherein the inner peripheral surface, the second end surface and the outlet channel are formed in the rear housing,
 the first end surface is formed by a disk-shaped lid member that is fitted inside the inner peripheral surface and separates the discharge chamber and the muffler chamber from each other, and   the inlet channel is formed in the lid member.   
     
     
         3 . The variable displacement compressor with single-head pistons according to  claim 2 , wherein the inner peripheral surface and the second end surface forma closed-end circular hole that is recessed in the discharge chamber toward the other end side, and
 the outlet channel is a straight hole that penetrates the rear housing from the one end side to the inner peripheral surface.   
     
     
         4 . The variable displacement compressor with single-head pistons according to  claim 1 , wherein an inner diameter of the outlet channel is larger than an inner diameter of the inlet channel. 
     
     
         5 . The variable displacement compressor with single-head pistons according to  claims 1 , wherein an intermediate member is fitted inside the inner peripheral surface, the intermediate member dividing the muffler chamber into a first muffler chamber positioned on the one end side and a second muffler chamber positioned on the other end side,
 a first opening, a second opening and an intermediate flow channel are formed in the. intermediate member, and   the first opening opens into the first muffler chamber, the second opening opens into the second muffler chamber, and the intermediate flow channel provides communication between the first opening and the second opening.   
     
     
         6 . The variable displacement compressor with single-head pistons according to  claim 5 , wherein the intermediate member includes a disk-shaped main body part and an extension part that is integral with the main body part and extends toward the one end side,
 the first opening is formed in the extension part at a position on the one end side,   the second opening is formed in the main body part at a position on the other end side, and   the intermediate flow channel is formed between the extension part and the main body part of the intermediate member and the inner peripheral surface.   
     
     
         7 . The variable displacement compressor with single-head pistons according to  claim 5 , wherein a plurality of the intermediate members arranged side by side in the axial direction are fitted inside the inner peripheral surface, and
 the first opening, the second opening and the intermediate flow channel formed in one of adjacent two of the intermediate members are displaced from the first opening, the second opening and the intermediate flow channel formed in the other of the adjacent two of the intermediate members when viewed in the axial direction.   
     
     
         8 . The variable displacement compressor with single-head pistons according to  claim 1 , wherein an agitating member is inserted in the muffler chamber, the agitating member having a plurality of reflecting surface elements whose reflecting surfaces intersect with the axial direction.