Patent ID: 6368072
Filing Date: 2002-04-09
Classification: F04B

Abstract:
A hydraulic pump comprising:a cylinder block rotatably supported in a housing; a plurality of cylinders arranged on a circle a center of which coincides with a center axis of the cylinder block; pistons respectively reciprocating in the cylinders; a suction port and a discharge port provided to the housing selectively communicating with one end of the respective cylinders in accordance with a rotational position of the cylinder block; a drive shaft inclined relative to the center axis of the cylinder block; rotation transmitting means for transmitting rotation of the drive shaft to the cylinder block to thereby rotate the cylinder block synchronously with the drive shaft; a rotating disk rotating together with the drive shaft and cooperatively engaged with the pistons at another end of the respective cylinders; a fixed sliding contact face formed in the housing, the fixed sliding contact face being brought into sliding contact with a rear face of the rotating disk; pressure pockets formed on the rear face of the rotating disk in correspondence with positions of the respective pistons; pressure paths for conducting hydraulic pressure in the respective cylinders to the respective pressure pockets via the pistons; and pressure introducing means for introducing a high pressure fluid to a pocket moving along the fixed sliding contact face along with the rotating disk at a position in which a corresponding cylinder is about to switch from a suction stroke to a discharge stroke.