TRANSFER OIL PRESSURE SUPPLY DEVICE FOR FOUR WHEEL DRIVE VEHICLE

摘要

PURPOSE: To suppress the aeration of a main pump after sucking a working oil from the strainer of a subpump through a bypass path when the main pump reverses during the moving back of a vehicle, by returning the working oil from the strainer of the main pump to an oil tank. ;CONSTITUTION: An oil pressure supply device 4 uses a main pump 20 normally and reversely rotated by the output shaft 56 of a speed change gear and a subpump 24 rotated normally by an electric motor 22 for an oil pressure source, and supplys a working oil in an oil tank 46 to a variable torque clutch in a transfer 7 at fixed clutch pressure for transmitting driving torque to a front and a rear wheel at a fixed distribution ratio In such a formation, strainers 20b, 24b are severally arranged in the suction pathes 20a, 24a of both the above pumps 20, 24. In addition, a bypass path 48 is formed between the strainer 24b of the subpump 24 and the delivery path 20c of the main pump being in normal rotation, and a check valve 48b opening when pressure is negative in the delivery path 20c is arranged in the bypass path 48.;COPYRIGHT: (C)1995,JPO