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.
Patent No.:
Date of Patent:
Feb. 25, 1992
Filed:
Dec. 27, 1990
Mikio Suzuki, Hekinan, JP;
Satoshi Suto, Okazaki, JP;
Ikuo Okuda, Okazaki, JP;
Yasunori Nakawaki, Susono, JP;
Akiharu Abe, Susono, JP;
Toyoda Koki Kabushiki Kaisha, Kariya, JP;
Abstract
A variable-displacement vane-pump has a rotor which is rotatably supported by a pump housing in coaxial relationship therewith, and a cam ring interposed between the rotor and the pump housing in eccentric relationship with the pump housing. The rotor has radially outwardly slidable vanes on its outer peripheral surface in contact with an inner surface of the cam ring. Two side plates are disposed on both sides of the vanes, thereby defining pump chambers between every adjacent vanes. An arc-shaped intake port and an arc-shaped exhaust port are formed in one of two side plates, and respectively open into the pump chambers along one side face of the cam ring. In the other side face of the cam ring, a groove is formed except for the region corresponding to the exhaust port, and a partially cut off annular friction ring is disposed within the groove while urged by a seal ring into close contact with the other side plate. A pressure compensating recess having a configuration which conforms to that of the exhaust port and communicating with the pump chambers is formed in the other side face of the cam ring except for the region wherein the groove for the friction ring is formed.