Energy efficient electric vehicle control system
AssigneeParker Hannifin Manufacturing Limited
InventorThomas McCann
Life of this patent
Estimating the term…
Abstract
An electric vehicle comprises an electrical system and a hydraulic system. The electrical system comprises an electric power supply and an electric motor-generator connected to the drive train of the vehicle. The hydraulic system includes a pump, and a hydraulic actuator. At least one of the electrical system and the hydraulic system includes energy recovery means arranged to convert kinetic energy from the drive train to electrical energy or to convert kinetic energy from the hydraulic actuator into hydraulic pressure respectively. The electrical and hydraulic systems are connected such that the recovered energy may be converted from electrical to hydraulic energy and/or vice versa. The hydraulic system may further include a hydraulic accumulator.
Claims14
A lift truck comprising:
- an electrical system comprising an electric power supply and an electric motor-generator connected to a drive train of the lift truck;
- and
- a hydraulic system for causing lifting of and additional auxiliary movements of a lift of the lift truck, the hydraulic system including a hydraulic pump/motor, a main hydraulic actuator configured to raise and lower the lift, and one or more auxiliary hydraulic actuators configured to cause the additional auxiliary movements of the lift;
- wherein the hydraulic system is configured to selectively redirect hydraulic power from the main hydraulic actuator to hydraulically power the one or more auxiliary actuators without redirection of said hydraulic power first to the hydraulic pump/motor.
A lift truck comprising:
- a battery;
- an inverter drive electrically connected to the battery and connected to a first motor/generator, a traction drive/brake coupled to the first motor/generator;
- a second inverter drive electrically connected to the battery and connected to a second motor/generator;
- and
- a hydraulic pump/motor coupled to the second motor/generator and hydraulically connected to a hydraulic lift circuit for causing lifting of and additional auxiliary movements of a lift of the lift truck, the hydraulic lift circuit including a main hydraulic actuator configured to raise and lower the lift, and one or more auxiliary hydraulic actuators configured to cause the additional auxiliary movements of the lift;
- wherein hydraulic power from actuation of the main hydraulic actuator is selectively redirected to hydraulically power the one or more auxiliary actuators without redirection of said hydraulic power first to the hydraulic pump/motor.
Dependencies are inferred from the claim text.