Abstract: A failure detection device for a hydraulic motor of the present invention comprises a hydraulic pump 3 that is driven by a prime mover 2; a hydraulic motor 1 that is driven by hydraulic oil discharged from the hydraulic pump 3; an abnormality detection device 35 that detects an abnormal operation of the hydraulic motor 1; and a warning device 30, 39, 40 that issues a warning when the abnormal operation of the hydraulic motor 1 is detected by the abnormality detection device 35.

Abstract: A failure detection device for a hydraulic motor of the present invention comprises a hydraulic pump 3 that is driven by a prime mover 2; a hydraulic motor 1 that is driven by hydraulic oil discharged from the hydraulic pump 3; an abnormality detection device 35 that detects an abnormal operation of the hydraulic motor 1; and a warning device 30, 39, 40 that issues a warning when the abnormal operation of the hydraulic motor 1 is detected by the abnormality detection device 35.

Abstract: A prime mover revolution speed control system for a hydraulically propelled vehicle controls the revolution speed of a prime mover to optimize vehicle acceleration in a vehicle propelling mode, and to optimize engine output and economy in a working mode. A vehicle equipped with the control system may include a hydraulic pump for discharging hydraulic fluid, the amount of fluid discharged depending on the revolution speed of the prime mover, a hydraulic motor for vehicle propulsion that is driven by hydraulic fluid discharged from the hydraulic pump, and an actuator for performing work that is also driven by hydraulic fluid discharged from the hydraulic pump. The revolution speed of the prime mover may be controlled according to a depression amount of a revolution speed control pedal. When the control system is in the working mode, the revolution speed of the prime mover is controlled in accordance with revolution speed characteristics suitable for a working operation.