公开(公告)号：US3987768A

公开(公告)日：1976-10-26

申请号：US433094

申请日：1974-01-14

申请人： Billie Gene Hunck ,  James Henry Kress

发明人： Billie Gene Hunck ,  James Henry Kress

IPC分类号： F16H39/02 ,  B60K17/30

CPC分类号： F16H61/444 ,  F16H39/02

摘要： An auxiliary hydrostatic drive system for a vehicle includes a pump, a reservoir, fluid motors connected to the normally non-driven steerable wheels of the vehicle, reciprocating piston-type wheel drive motors connected to the normally nondriven steerable wheels, fluid lines interconnecting the pump and reservoir with the inlet and outlet ports of the wheel motors, and a motor control valve movable to either side of a neutral fluid blocking position to forward and reverse drive positions. An additional valve interconnects the motor ports with the drive chambers of the motors whenever the motor control valve is in the neutral position so that during periods when the motors are not connected to the pump and are driven mechanically, they function as pumps to pressurize their drive chambers and hold their pistons off the drive cams.