Patent ID: 6941688

Claim:
A hydraulically powered vehicle comprising: a hydraulic pump which is driven by an engine; a hydraulic motor for vehicle propulsion which is driven by pressurized hydraulic fluid discharged from the hydraulic pump; at least one hydraulic actuator for working which is driven by pressurized hydraulic fluid discharged from the hydraulic pump; an accelerator pedal which adjusts a rotational speed of the hydraulic motor for vehicle propulsion without changing a rotational speed of the engine; an operation lever device which operates the hydraulic actuator for working; a rotational speed adjustment device which adjusts the rotational speed of the engine; and a rotational speed control device which controls the rotational speed adjustment device; wherein the rotational speed control device controls the rotational speed adjustment device so that, upon transition from a vehicle propulsion state to a non-propulsion state, the rotational speed of the engine is reduced to an idling rotational speed for vehicle propulsion, and upon transition from a working state to a non-working state, the rotational speed of the engine is reduced to an idling rotational speed for working.