Patent attributes
A fluid drive system that can be used to drive a vehicle and has energy regeneration and storage capabilities. The fluid drive system includes an electrical energy supply source mounted on the vehicle, at least one electrical motor electrically connected to the electrical supply source, and a hydraulic pump driven that may be of the variable displacement type by the electrical motor. The fluid drive system may also include a low pressure hydraulic fluid supply tank supplying fluid to the hydraulic pump, at least one pneumatically charged accumulator tank for storing pressurized hydraulic fluid, a combination hydraulic motor and pump that may also be of the variable displacement type being alternately driven by the hydraulic pump and the pneumatically charged accumulator tank; and an electrical regeneration system for regenerating the electrical energy supply. The electrical regeneration system may be powered by hydraulic fluid from the combination electrical motor and pump. The combination hydraulic motor and pump propels the vehicle during acceleration and speed maintaining operations and may also serves as a braking mechanism during deceleration of the vehicle. The combination hydraulic motor and pump may also pump hydraulic fluid into the pneumatically charged accumulator tank during at least a portion of the time that the vehicle is decelerating. The combination hydraulic motor and pump may further pump hydraulic fluid for powering the electrical regeneration system when the pneumatically charged accumulator tank is fully pressurized. The electrical regeneration system also has the ability to recharge the electrical energy supply while the vehicle is stopped using stored recovered kinetic energy.
