PURPOSE: To reduce the occurrence of delivery pulsation of a liquid pump throughout a wide range of the number of revolutions.
CONSTITUTION: A variable displacement swash plate type axial plunger pump 10 changes the inclination angle of a non-rotating swash plate 18 by means of a capacity control piston 17 to vary a delivery amount. In control through which a delivery amount is maintained at a constant value when the number of revolutions of a rotary shaft 14 is fluctuated, a control oil pressure having magnitude responding to the number of revolutions is fed to a hole part 13b to move the piston 17. In structure shown in a figure, displacement of the piston 17 is transferred to a spool 320 through a rod 312, and the volume of a resonance chamber 322 and the length of a communicating pipe between a delivery passage 30 and a cylindrical passage 323 are simultaneously changed. Since the resonance frequency of a resonator 300 is changed in response to the number of revolutions and thus the frequency of delivery pulsation, a resonance frequency can coincide with the frequency of pulsation in any running state, and the occurrence of delivery pressure pulsation can be reduced in a wide range of the number of revolutions.
| JPH06129344 | AXIAL PISTON MACHINE |
| JPH0763262 | HTDRAULIC CONTINUOUSLY VARIABLE TRANSMISSION OPERATING DEVICE |
KUBOSHIMA TSUKASA
NAKAMURA KANEHITO
