Method of changing speed and torque with a continuously variable vane-type machine

摘要

A continuously variable transmission comprises a housing, an input shaft, an output shaft. The input shaft is coupled to a vane rotor of a vane-type pump having radially extending pump vanes driven by the pump rotor around a pump working volume between two axially spaced pump side plates surfaces and within an inside surface of a flexible pump cam ring spaced radially from the pump rotor. The pump vanes each have a radial end edge remote from the pump rotor and in contact with the pump cam surface. A stator hub is fixed to the housing and has radially extending stator vanes projecting radially into a stator working volume between two axially spaced stator side plate surfaces and between a cam surface of a flexible stator cam ring and the radially spaced surface of the stator hub. The stator vanes each have a radial end edge remote from the hub and in contact with the stator cam surface. Torque is transmitted from the stator cam ring and the pump cam ring to the output shaft by a torque coupling. Fluid openings are provided for passing fluid pressurized in the pump directly from the pump working volume into the stator, and for passing fluid displaced from the stator directly from the stator working volume into suction sectors of the pump. A cam ring adjustment mechanism is mounted in the housing for changing the radial spacing of portions of the pump cam ring from the pump rotor, and for changing the radial spacing of portions of the stator cam ring from the stator hub. Rotation of the pump rotor by the input shaft pressurizes fluid in the pump working volume which acts against the pump cam ring to generate torque that is transmitted to the output shaft, and the pressurized fluid in the pump working volume communicates through the fluid openings to pressurize fluid in the stator working volume which acts against the stator cam ring to generate additional torque that is transmitted to the output shaft, and the cam adjustment mechanism is operated to reciprocally change the displacement of the pump and the stator to change the transmission ratio of the transmission.