US 7,320,576 B2
Clutchless variable displacement refrigerant compressor with mechanism for reducing displacement work at increased driven speed during non-operation of refrigerating system including the compressor
Anri Enomoto, Isesaki (Japan); and Yoshihiro Ochiai, Isesaki (Japan)
Assigned to Sanden Corporation, Gunma (Japan)
Filed on Aug. 26, 2003, as Appl. No. 10/647,218.
Claims priority of application No. 2002/247273 (JP), filed on Aug. 27, 2002.
Prior Publication US 2004/0076527 A1, Apr. 22, 2004
Int. Cl. F04B 1/12 (2006.01); F04B 1/26 (2006.01)
U.S. Cl. 417—269  [417/222.1; 417/222.2] 14 Claims
OG exemplary drawing
 
1. A clutchless refrigerant compressor of a variable displacement type comprising:
a compressor housing having therein a crank chamber, at least one cylinder bore, a suction chamber, and a discharge chamber, said suction chamber and a discharge chamber having an inlet port and an outlet port, respectively, for connecting the compressor to a refrigerating circuit;
at least one piston fitted into said at least one cylinder bore and reciprocating within said cylinder bore;
a drive shaft extending in the crank chamber in a direction parallel to said cylinder and said piston and rotatably born in the compressor housing, said drive shaft having an axial end portion protruding outward from the compressor housing, said axial end portion being for connecting an external driving source for receiving a driving power to rotate said drive shaft;
a rotor fixedly mounted on said drive shaft within said crank chamber to be rotatable together with said drive shaft;
a swash plate disposed around said drive shaft and connected to said rotor by a hinge connection at an angular position, as a hinge angular position, around said drive shaft so as to be rotatable together with said rotor and to be able to inclined from a plane perpendicular to a drive axis of said drive shaft, said swash plate making a nutating motion with an inclination angle by rotation together with said rotor, the inclination angle of said swash plate being variable between a predetermined minimum angle approximately equal to a zero angle and predetermined maximum angle;
a connecting mechanism connecting said swash plate to said piston for converting said nutating motion of said swash plate to reciprocating motion of said piston;
a control mechanism for controlling said inclination angle of said swash plate together or against said urging member by adjusting a pressure within said crank chamber to thereby control the displacement of said compressor;
determining means for determining the inclination angle of the swash plate to an initial angle when said drive shaft is stopped without being driven by the external driving source, the initial angle being selected larger than the predetermined minimum angle;
an urging member providing an urging force to urge the swash plate so that the inclination angle becomes the predetermined minimum angle, wherein said inclination angle determining means comprises a stopper mounted on said drive shaft at an initial position on the drive axis to stop said swash plate from changing in inclination due to the urging force when said drive shaft is not driven by said external driving source, for defining an initial angle of the inclination angle of the swash plate, said stopper being variable in the position on said drive axis; and
releasing means for releasing the inclination angle determining means when compression work of the compressor is increased after said drive shaft is driven by the external driving source, wherein said releasing means comprises:
a detector for detecting a physical factor corresponding to compression work of said compressor;
a driver connected to said detector and said inclination angle determining means for, when said physical factor detected shows increase of said compression work, releasing said inclination angle determining means.