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Patent Searching and Data


Title:
VARIABLE DISPLACEMENT ROTARY PUMP
Document Type and Number:
Japanese Patent JP2010053692
Kind Code:
A
Abstract:

To prevent generation of impact and noise when switching to high capacity operation from low capacity operation, in a variable displacement rotary pump.

Switching to 100% operation from 50% operation of a variable displacement gear pump is performed without carrying an electric current to an electromagnet. A spool valve 55 moves backward, and an annular groove 57 communicates with a through-hole 61 and a groove 62. Delivery oil flows in an inside space 50 from a delivery pressure communicating passage 63, and moves a spool valve 44 forward. When the spool valve 44 moves to a finishing stage of closing operation of an opening-closing valve 42, an annular groove 51 of the spool valve 44 slips out of a communicating state with the through-hole 61. Oil is restricted by a clearance 67, and is supplied to the annular groove 51. Since a supplied oil quantity is reduced, a moving speed of the spool valve 44 is reduced, and a valve part 46 abuts on a valve seat 48 at a slow speed, and completes closing operation of a bypass passage 32. Thus, generation of the impact and the noise when closing the bypass passage 32 can be prevented.


Inventors:
MITSUDA SATOSHI
FUJII TOSHIRO
SUZUKI SHIGERU
YOKOI HIRONAO
Application Number:
JP2008216263A
Publication Date:
March 11, 2010
Filing Date:
August 26, 2008
Export Citation:
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Assignee:
TOYOTA IND CORP
International Classes:
F04C14/26; F04C11/00; F04C15/06
Domestic Patent References:
JPS63105289A1988-05-10