HYDRAULIC TRANSMISSION DEVICE

摘要

A hydraulic transmission device (20) comprising a variable displacement pump (24) supplying one or a plurality of hydraulic motors (26A, 26B), and a control unit (50). In the device, the supply and exhaust ports of the motors are arranged such that when the pressures in these ports are equal, the output torque of the motors is zero. In order to make the device inactive without physically bypassing the motors, the control unit is capable of operating the device in a "no torque" mode by regulating the displacement of the pump in such a way that the pressures at said supply and exhaust ports remain substantially equal.