Hydraulic brake energy regeneration system for electric energy storage and vehicle drive assist

A hydraulic drive system for storing and releasing hydraulic fluid includes a high pressure storage device, a low pressure storage device, a pump operating at a range of pump speeds for converting between mechanical energy and hydraulic energy, and a motor operating at a range of motor speeds for converting between hydraulic energy and mechanical energy. The pump and motor are both fluidly connected to the high and low pressure storage devices. The hydraulic drive system further includes a control valve fluidly connected to the high pressure storage device, the pump and the motor, the control valve being operable to selectively distribute high pressure fluid between the pump, motor and high pressure storage device.