Patent ID: 6226987
Filing Date: 2001-05-08
Classification: F16D,F16H

Abstract:
A travel drive apparatus for a hydraulic drive work vehicle including a travel variable delivery hydraulic pump driven by power from an engine; a fixed capacity hydraulic pump which discharges pressure oil corresponding to an engine turning speed; a hydraulic motor that receives oil discharged from the variable delivery hydraulic pump and moves a vehicle at or below a prescribed speed; and a travel changeover valve that receives the discharged oil from the variable delivery hydraulic pump, supplies the discharged oil to the hydraulic motor, and discharges return oil from the hydraulic motor to a tank, the apparatus comprising:a horsepower control mechanism that is linked to the variable delivery hydraulic pump and activated by receiving pressure oil discharged from the variable delivery hydraulic pump and supplied to the hydraulic motor and pressure oil discharged from the fixed capacity hydraulic pump, the horsepower control mechanism being configured to control the variable delivery hydraulic pump such that, when the engine turning speed is at or below a prescribed value and the hydraulic motor is driven by inertial energy of the vehicle, a flow rate of the pressure oil supplied to the hydraulic motor reaches or exceeds a prescribed value.