A torque converter oil cooling system includes an air-oil cooler system that is adapted to be disposed between a torque converter charging oil outlet and charging oil inlet. The torque converter oil cooling system has a controller that directs oil when at a predetermined temperature to pass through an air oil cooler for cooling and then directs the cooled oil back to the inlet of the torque converter for torque converter operation. The torque converter oil cooling system normally operates in the non-lockup mode operation of the torque converter. Using the torque converter oil cooling system permits a vehicle to continuously operate in a torque converter mode for an extended period of time, which becomes extremely helpful when the vehicle is called upon to haul heavy loads over steep grades.

Systems and methods for launching a hybrid vehicle that includes a motor/generator and an automatic transmission with a torque converter are described. The systems and methods may permit improved vehicle acceleration to enhance hybrid vehicle performance during specific vehicle launch conditions. The launch conditions may be established based on brake pedal position and accelerator pedal position.

Systems and methods for launching a hybrid vehicle that includes a motor/generator and an automatic transmission with a torque converter are described. The systems and methods may permit improved vehicle acceleration to enhance hybrid vehicle performance during specific vehicle launch conditions. The launch conditions may be established based on brake pedal position and accelerator pedal position.

A drag torque reduction device for an automatic transmission includes a hydraulic controller with a radiator. In one embodiment, the drag torque reduction device also includes a parallel connection of a pressure relief valve, a constant aperture and a temperature-dependent, switchable aperture positioned upstream of the radiator. In another embodiment, the drag torque reduction device includes an overflow cooling oil diversion with a temperature-dependent, switchable aperture and a pressure relief valve that is positioned upstream of the radiator.

A drag torque reduction device for an automatic transmission includes a hydraulic controller with a radiator. In one embodiment, the drag torque reduction device also includes a parallel connection of a pressure relief valve, a constant aperture and a temperature-dependent, switchable aperture positioned upstream of the radiator. In another embodiment, the drag torque reduction device includes an overflow cooling oil diversion with a temperature-dependent, switchable aperture and a pressure relief valve that is positioned upstream of the radiator.

A control apparatus for a dynamic power transmission apparatus is provided. The dynamic power transmission apparatus includes a differential mechanism, an electric generator, an electric motor, and a fluid coupling. The electric motor is disposed at a position apart from a transmission path along which a dynamic power of an engine is transmitted to a driving wheel. The fluid coupling is disposed between the electric motor and the transmission path. The control apparatus includes an electronic controller configured to restrict a charge of an electric storage apparatus with an electric power generated by the electric generator, depending on a state of the electric storage apparatus, and control the fluid coupling to differentially rotate and to drive the electric motor by the electric power such that a dynamic power loss is generated in the fluid coupling, when restricting the charge of the electric storage apparatus.

Systems and methods for operating a hybrid vehicle driveline that includes an engine and a motor are presented. In one example, the systems and methods include one or more control modes where engine and/or motor speed or torque is adjusted responsive to different control parameters during a vehicle launch from zero speed or a creep speed.

Systems and methods for operating a hybrid vehicle driveline that includes an engine and a motor are presented. In one example, the systems and methods include one or more control modes where engine and/or motor speed or torque is adjusted responsive to different control parameters during a vehicle launch from zero speed or a creep speed.

A hydraulic control system provides lubrication fluid to a gearbox via two flow paths in parallel. One of the flow paths includes a passive thermal valve in series with a heat exchanger. When the fluid temperature is elevated, the thermal valve opens such that fluid flows through the heat exchanger for cooling. The thermal valve restricts flow to the heat exchanger when transmission fluid is in a normal operating temperature range, reducing flow demands. When the flow demands are reduced, a variable displacement pump requires less torque improving fuel economy. The thermal valve may also open when the fluid is below the normal operating temperature such that the heat exchanger heats the fluid. The parallel path may include a regulator valve. When the pressure of fluid in the lubrication circuit is elevated, the regulator valve reduces flow through the parallel path and may also divert flow to a sump.

A hydraulic control system provides lubrication fluid to a gearbox via two flow paths in parallel. One of the flow paths includes a passive thermal valve in series with a heat exchanger. When the fluid temperature is elevated, the thermal valve opens such that fluid flows through the heat exchanger for cooling. The thermal valve restricts flow to the heat exchanger when transmission fluid is in a normal operating temperature range, reducing flow demands. When the flow demands are reduced, a variable displacement pump requires less torque improving fuel economy. The thermal valve may also open when the fluid is below the normal operating temperature such that the heat exchanger heats the fluid. The parallel path may include a regulator valve. When the pressure of fluid in the lubrication circuit is elevated, the regulator valve reduces flow through the parallel path and may also divert flow to a sump.