The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
May. 21, 1996

Filed:

Jan. 30, 1995
Applicant:
Inventors:

Tadaaki Fujii, Saitama, JP;

Hiroto Iwata, Saitama, JP;

Yuuichi Kimura, Saitama, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F04C / ;
U.S. Cl.
CPC ...
418 26 ; 418 27 ; 418 30 ;
Abstract

A cam ring for forming a pump chamber on the outer periphery of a rotor which is rotatable in a body is arranged movably, and is urged in a direction in which the volume of the pump chamber is made maximum. Sealing means are interposed in an annular gap space on the outer periphery of the cam ring between the cam ring and the body, thereby forming first and second fluid-pressure chambers for allowing the cam ring to undergo displacement by moving. A spool-type changeover valve is provided which is operated in accordance with the discharge flow rate of the pressure fluid from the pump chamber to control the fluid pressure supplied to the first and second fluid-pressure chambers. The fluid pressure on the downstream side of a metering orifice 29 provided in a pump discharge-side passage 28 is introduced into the second fluid-pressure chamber for imparting moving displacement in the direction in which the volume of the pump chamber is made maximum, through a passage 37 via a second valve chamber 32b. It is possible to control the swinging of the cam ring, and to prevent fluctuations in the flow rate and a decline in the flow rate on the discharge side of the pump.


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