Patent ID: 9097113
Filing Date: 2015-08-04
Classification: F01B,F04B,F04C

Abstract:
1. An axial type hydraulic pump/motor in which a cylinder block provided with a plurality of cylinder bores slides on a valve plate provided with suction and delivery ports and pistons reciprocate inside the respective cylinder bores to rotate an output shaft or an input shaft rotates to discharge hydraulic oil from the suction and delivery ports, the hydraulic pump/motor comprising: two pressure accumulation oil passages which accumulate pressure in two connecting passages that are obtained in a manner such that, among two pairs of ports provided on the valve plate and provided at a top dead center side and a bottom dead center side outside a slide and rotation trajectory area of the cylinder bores, a top dead center side port on a front side in a rotation direction of the cylinder block is connected to a bottom dead center side port on the front side in the rotation direction and a top dead center side port on a rear side in the rotation direction is connected to a bottom dead center side port on the rear side in the rotation direction, wherein each cylinder bore includes two communication holes that communicate with inside of the respective cylinder bore and of which opening portions slide on the respective ports with rotation of the cylinder block to communicate with the pressure accumulation oil passages, and wherein each of the ports of each of the pressure accumulation oil passages exclusively communicates with the communication holes so that a pressure accumulation operation is performed in which pressure inside of one of the cylinder bores is in a corresponding one of the pressure accumulation oil passages through one of the communication holes and an accumulated pressure collection operation is performed in which the pressure accumulated in the pressure accumulation oil passage is collected in another of the cylinder bores.