Abstract: An automatic transmission includes a control system for controlling a clutch of the transmission. The control system includes a first variable flow solenoid and a second variable flow solenoid, each in selective fluid communication with the clutch. The first variable force solenoid provides hydraulic fluid within a first pressure range of 0 and 1,000 kPa. The second variable force solenoid provides hydraulic fluid within a second pressure range of 0 and 2,000 kPa. A transmission controller sends an electrical signal having a current between the range of 0 and 1 amp to one of the first and second variable flow solenoids. The pressure output of each of the first and second variable force solenoids is a function of, within their respective first and second pressure ranges, the amplitude of the current of the electrical signal to provide two distinct power gains to the single clutch.

Abstract: A torque distribution system for a vehicle permits the transfer of torque between vehicle wheels using a selectively engagable clutch that is hydraulically engaged using hydraulic pressure provided by a hydraulic transmission pump driven by the engine, allowing for enhanced system functionality and reduced part content in comparison with known torque distribution systems. The system may include an “active-on-demand” clutch that is selectively engagable to transfer torque between a front differential and a rear differential (thereby transferring torque from the front wheels to the rear wheels) as well as an electronically-limited slip differential clutch selectively engagable to transfer torque from one front wheel to the other front wheel through the front differential. Utilization of the transmission hydraulic pump allows pressure to be provided to engage the clutch even when the wheels are stationary, i.e., to launch the vehicle.

Abstract: An automatic transmission includes a control system for controlling a clutch of the transmission. The control system includes a first variable flow solenoid and a second variable flow solenoid, each in selective fluid communication with the clutch. The first variable force solenoid provides hydraulic fluid within a first pressure range of 0 and 1,000 kPa. The second variable force solenoid provides hydraulic fluid within a second pressure range of 0 and 2,000 kPa. A transmission controller sends an electrical signal having a current between the range of 0 and 1 amp to one of the first and second variable flow solenoids. The pressure output of each of the first and second variable force solenoids is a function of, within their respective first and second pressure ranges, the amplitude of the current of the electrical signal to provide two distinct power gains to the single clutch.

Abstract: A torque distribution system for a vehicle permits the transfer of torque between vehicle wheels using a selectively engagable clutch that is hydraulically engaged using hydraulic pressure provided by a hydraulic transmission pump driven by the engine, allowing for enhanced system functionality and reduced part content in comparison with known torque distribution systems. The system may include an “active-on-demand” clutch that is selectively engagable to transfer torque between a front differential and a rear differential (thereby transferring torque from the front wheels to the rear wheels) as well as an electronically-limited slip differential clutch selectively engagable to transfer torque from one front wheel to the other front wheel through the front differential. Utilization of the transmission hydraulic pump allows pressure to be provided to engage the clutch even when the wheels are stationary, i.e., to launch the vehicle.