To prevent degradation in the confining performance on a working fluid in a pump chamber caused by separation of a vane from a cam surface in a confining region of a variable displacement vane pump.
The variable displacement vane pump 100 varies a discharge volume of a working fluid from a pump chamber 7 by changing an eccentricity quantity of a cam ring 4 with respect to a rotor 2, which changes a diameter from the center of the rotor 2 to the cum surface 4a. The cam ring 4 includes a sucking region 41 that expands the capacity of the pump chamber 7 with rotation of the rotor 2, a discharge region 42 that contracts the capacity of the pump chamber 7, and confining regions 43, 44 disposed between the sucking region 41 and the discharge region 42, where a low pressure in the sucking region 41 and a high pressure in the discharge region 42 are switched to each other. The confining regions 43, 44 are set in such a manner that a pole where increase and decrease in a diameter from the center of the rotor 2 to the cum surface 4a change over each other with the rotation of the rotor 2 appears outside the confining regions 43, 44 regardless of the eccentricity quantity of the cam ring 4.
| JP2009127457A | 2009-06-11 | |||
| JP3743929B2 | 2006-02-08 |
Masahiro Fujii
Masaaki Iida
Atsushi Sudo
Kei Takeda