Hydromechanical transmissions

A hydromechanical transmission for driving a vehicle, comprising a torque converter component, a complimentary mechanical gear component, a feeder fluid pump system component, a valve system component and an automatic and a manual control means component, wherein:

• (A) the torque converter component comprises at least one pump member, at least one guide member and at least one turbine member with a ring of turbine blades following the pump member, a direct drive lock-up clutch and a friction clutch permitting the guide member to be locked against rotation in at least one direction;
• (B) the complimentary mechanical gear component is a servo-motor controlled multiple speed mechanical gear of the power shift type having one planet gear carrier and a plurality of planetary gears providing a plurality of different gear ratios;
• (C) the feeder fluid pump system component is servo-motor controlled and includes at least one variable capacity pump unit;
• (D) the valve system component includes one disc valve arrangement for controlling the flow of feeder fluid through the converter, with the valves thereof adapted to open and close relatively large port areas upon relatively short movements of the valves and a second disc valve arrangement for controlling the flow of feeder fluid to the complimentary mechanical gear servo-motors with the valves thereof adapted to open and close relatively large port areas upon relatively short movements of the valve;
• and
• (E) the automatic control means component includes a microprocessor for receiving input signals relating to "primary speed", "output shaft speed" and "fuel injection settings" and for processing said signals in accordance with preprogrammed memories and according to manual settings so as to produce output signals to determine operation of the torque converter component and the complimentary mechanical gear component.