To provide a pump device capable of minimizing a load by gradually increasing oil pressure and discharge corresponding to values required by an engine and hydraulic equipment.
The pump device includes a housing A; a pump including a drive gear unit 5 and a driven gear unit 4; a main passage 31 through which oil pressure is applied to the driven gear unit 4 in a discharge decrease direction; a first branch passage 32 through which oil pressure is applied to assist oil pressure from the main passage 31; a second branch passage 33 through which oil pressure is applied to the driven gear unit 4 in a discharge increase direction; a first passage control section C for controlling the flow of the first branch passage 32; a second passage control section D for controlling the flow of the second branch passage 33; and a spring 81 for elastically energizing the driven gear unit 4 in the discharge increase direction. The first passage control section C and the second passage control section D perform switching control to either make the first branch passage 32 communicate with the second branch passage 33 or to block the communication according to the increase/decrease of engine speed and the increase/decrease of pressure.
| JP2017155722 | OIL PUMP |
| WO/2004/003345 | INTERNAL GEAR MACHINE WITH VARIABLE CAPACITY |
| JP5230971 | Gear pump |
MIYAJIMA JUNICHI
IZUTSU MASATO
WATANABE TAKATOSHI
| JP2010001742A | 2010-01-07 | |||
| JP2009019773A | 2009-01-29 | |||
| JP2010001742A | 2010-01-07 | |||
| JP2009019773A | 2009-01-29 |
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