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:
Oct. 14, 2008
Filed:
Mar. 22, 2006
Kazuo Enzaka, Gunma-ken, JP;
Yasunori Ono, Gunma-ken, JP;
Sentaro Nishioka, Gunma-ken, JP;
Masahiro Kasahara, Gunma-ken, JP;
Atsushi Kaneko, Gunma-ken, JP;
Kazuo Enzaka, Gunma-ken, JP;
Yasunori Ono, Gunma-ken, JP;
Sentaro Nishioka, Gunma-ken, JP;
Masahiro Kasahara, Gunma-ken, JP;
Atsushi Kaneko, Gunma-ken, JP;
Yamada Manufacturing Co., Ltd., Kiryu-shi, JP;
Abstract
The present invention provides an oil pump in which eroding of the inside of the pump due to cavitation and erosion is prevented by minimizing the pressure change in a fluid when inter-tooth spaces formed by an inner rotor and an outer rotor transport the fluid from the intake port to the discharge port. The oil pump comprises: an inner rotor; an outer rotor; an intake port; a discharge port; a transfer side partition part formed between a terminal end of the intake port and a leading end of the discharge port; and a shallow groove which is formed in the transfer side partition part, and which communicates with the discharge port but does not communicate with the intake port. The shallow groove does not intersect with the cell on the transfer side partition part, and is positioned farther inward than the circular locus of the gear bottom parts of the inner rotor. The shallow groove communicates with the cell through a side clearance between the transfer side partition part and the rotor side surfaces of the inner rotor and the outer rotor.