HYDRAULIC PUMP/MOTOR WITH ROTATION DETECTION MECHANISM

摘要

The purpose of the present invention is to provide a hydraulic pump/motor with a rotation detection mechanism which is capable of detecting a rotation direction and the number of rotations of a rotation shaft with a simple structure and easily working a portion to be detected. To achieve the purpose, the rotation detection mechanism is provided with: a portion to be detected 52 including three or more depressed portions 6a to 6c (6) formed on an outer circumferential surface of a cylinder block 14, the three or more depressed portions 6 being formed in a unique arrangement pattern with different arc lengths R1 to R3 between the three continuous depressed portions with respect to a forward direction F of a rotation shaft 13 and being formed so as not to include the unique arrangement pattern with respect to a reverse direction B of the rotation shaft 13; and a rotation sensor 50 that is disposed in a casing in a state of being opposed to the portion to be detected 52 and that detects the portion to be detected 52. The three or more depressed portions 6 have the same semicircular shape in a cross section perpendicular to a direction along the rotation shaft 13.