Abstract: A vehicle drivetrain has a first driver, a first clutch to selectively couple the first driver with an engine, an energy storage device coupled to the first driver, a second driver coupled to the energy storage device and connected to a driveshaft, and a second clutch that selectively couples the first and second drivers. In one embodiment, the first clutch is opened and the second clutch is closed during a vehicle operating condition requiring high torque, the first clutch is closed and the second clutch is opened during a transient vehicle operating condition, and the first clutch and the second clutch are closed during a steady-state vehicle operating condition. Additional clutches may be included to reduce energy losses or provide multiple mechanical ratios. The drivers themselves may be pumps, motors, generators, combined pump/motors, or combined motor/generators, making the invention suitable for both hydraulic implementation and electric implementation.

Abstract: A vehicle drivetrain has a first driver, a first clutch to selectively couple the first driver with an engine, an energy storage device coupled to the first driver, a second driver coupled to the energy storage device and connected to a driveshaft, and a second clutch that selectively couples the first and second drivers. In one embodiment, the first clutch is opened and the second clutch is closed during a vehicle operating condition requiring high torque, the first clutch is closed and the second clutch is opened during a transient vehicle operating condition, and the first clutch and the second clutch are closed during a steady-state vehicle operating condition. Additional clutches may be included to reduce energy losses or provide multiple mechanical ratios. The drivers themselves may be pumps, motors, generators, combined pump/motors, or combined motor/generators, making the invention suitable for both hydraulic implementation and electric implementation.

Abstract: An exemplary pressure relief mechanism includes a reservoir having an interior cavity for retaining a fluid and a gas. The reservoir includes an aperture that fluidly connects the interior cavity to an exterior region of the reservoir. A rupture disk is arranged across the aperture in the reservoir and substantially blocks the fluid path through the aperture. The rupture disk is configured to open the fluid path through the aperture when a pressure within the interior cavity generally exceeds a predetermined level.