Patent ID: 6250077
Filing Date: 2001-06-26
Classification: F16H

Abstract:
A hydraulic continuously variable transmission for use on a vehicle, comprising:a hydraulic variable pump, which is driven by an engine;said hydraulic variable pump comprising a variable skew angle type swash plate pump;a hydraulic variable motor, which is driven by oil discharged from said hydraulic variable pump, said hydraulic variable motor driving drive wheels;said hydraulic variable motor comprising a variable skew angle type swash plate motor;shift position detecting means, which detects a shift position that is set with a shift lever operated by a driver;brake operation detecting means which detects operation of a vehicle brake by the driver:vehicle stop detecting means, which detects whether the vehicle is in halt or not;pump capacity controlling means, which controls discharge capacity of said hydraulic variable pump; andmotor capacity controlling means, which controls discharge capacity of said hydraulic variable motor;wherein:when said vehicle stop detecting means detects that the vehicle is in halt and said shift position detecting means detects that the shift position is in a forward drive position, said pump capacity controlling means controls the discharge capacity of said hydraulic variable pump to a first pump capacity for forward drive;said first pump capacity for forward drive is the capacity that said hydraulic variable pump discharges to supplement an amount of oil that leaks in the transmission when the vehicle is on an uphill road with said engine idling, thus retaining the vehicle in halt on the uphill road without any braking operation; andsaid motor capacity controlling means controls the discharge capacity of said hydraulic variable motor to a maximum discharge capacity of said hydraulic variable motor; andwhen said brake operation detecting means detects the operation of the brake, said pump capacity controlling means controls the discharge capacity of said hydraulic variable pump to a second pump capacity which is larger than zero and smaller than said first pump capacity.