PURPOSE: To provide a constant horse power control type variable capacity piston pump which is simplified and made compact in structure, by nearly incorporating a mechanical feedback mechanism in a tilting support shaft portion of a swash plate, without causing an unstable phenomenon in a control characteristic.
CONSTITUTION: The pump comprises a lever mechanism 9 for applying a mechanical input amount according to the discharge pressure to a control valve 5 which controls an oil pressure, applied to an operating piston, in proportion to the mechanical input amount, which varies depending upon the tilting angle of a swash plate so that a product of the discharge pressure and the discharge amount may be constant. This lever mechanism 9 comprises a small piston 91 eccentrically incorporated in a tilting support shaft, an oil passage 82 for leading the discharge pressure to a tail end of the small piston, and a pivotally movable lever member 94 for transmitting axial displacement of the small piston to the control valve 5. The length of the lever arm is varied through displacement in the amount of abutment between the small piston and the pivotally movable lever member in accordance with the tilting angle of the swash plate.
| JP2013087690 | VARIABLE DISPLACEMENT PISTON PUMP |
KAWAHARA HIROSHI
NOSE MINORU
TAKAHASHI HIDEO
TAKAHASHI ATSUSHI
KITAMURA TAKESHI
