초록 ▼

A hydraulically operated continuously variable transmission includes a hydraulic pump coupled to an input shaft, a variable-displacement hydraulic motor coupled to an output shaft, and a closed hydraulic circuit interconnecting the hydraulic pump and the hydraulic motor and including a passage conne

A hydraulically operated continuously variable transmission includes a hydraulic pump coupled to an input shaft, a variable-displacement hydraulic motor coupled to an output shaft, and a closed hydraulic circuit interconnecting the hydraulic pump and the hydraulic motor and including a passage connecting the inlet and outlet ports of the hydraulic pump. A servomotor makes and breaks the hydraulic circuit respectively by opening and closing the outlet port. A clutch valve continuously varies the cross-sectional area of the passage to change the amount of power transmitted between the hydraulic pump and the hydraulic motor. A control system independently controls the servomotor and the clutch valve, the control system being arranged to hold the servomotor in a position to open the outlet port when the clutch valve is opened beyond a prescribed degree. The hydraulic motor has motor plungers axially movable through a stroke which is variable by a tiltable motor swash plate which can be tilted by another servomotor. The servomotors include pilot valves which are operatively coupled to each other by a cam mechanism. The hydraulic circuit is kept broken when a motor vehicle incorporating the transmission runs at a prescribed speed or a higher speed and the angle of inclination of the motor swash plate is substantially minimal.

대표청구항 ▼

A hydraulically operated continuously variable transmission comprising: an input shaft; a hydraulic pump coupled to said input shaft and having inlet and outlet ports; an output shaft; a variable-displacement hydraulic motor coupled to said output shaft; a closed hydraulic circuit interconnecting sa

A hydraulically operated continuously variable transmission comprising: an input shaft; a hydraulic pump coupled to said input shaft and having inlet and outlet ports; an output shaft; a variable-displacement hydraulic motor coupled to said output shaft; a closed hydraulic circuit interconnecting said hydraulic pump and said hydraulic motor and including a passage connecting said inlet and outlet ports of the hydraulic pump; a servomotor for making and breaking said hydraulic circuit respectively by opening and closing said outlet port; a clutch valve for continuously varying the cross-sectional area of said passage to change the amount of power transmitted between said hydraulic pump and said hydraulic motor; and a control system for independently controlling said servomotor and said clutch valve, said control system being arranged to hold said servomotor in a position to open said outlet port when said clutch valve is opened beyond a prescribed degree.