Dual power electro-hydraulic motion control system
The present disclosure relates to a motion control unit that is capable of receiving electrical power from an electrical power source and hydraulic power from a hydraulic power source. The motion control is configured to produce a blended power output derived from the electrical and hydraulic power which can be used to power a hydraulic actuator. The motion control unit can also split hydraulic power recovered from hydraulic actuator to the electrical power source and the hydraulic power source.
1. A motion control device for powering a hydraulic actuator, the motion control device comprising:
a motion control unit adapted to be hydraulically connected to the hydraulic actuator having a rod side and a head side, the motion control unit also being configured to be electrically connected to an electrical power source and fluidly connected to a hydraulic power source, the motion control unit including an electric motor/generator, a hydraulic pump/motor and a mode-switching valve having three positions comprising a first position, a second position, and a third position and configured for allowing blended power from the electrical power source and the hydraulic power source to be transferred to the hydraulic actuator;
wherein the electric motor/generator is mechanically coupled to the hydraulic pump/motor;
wherein the hydraulic pump/motor includes a first port and a second port;
wherein the mode-switching valve includes six mode-switching valve ports, the valve ports including a first pump/motor port hydraulically connected to the first port of the hydraulic pump/motor by a first hydraulic fluid flow line, a second pump/motor port hydraulically coupled to the second port of the hydraulic pump/motor by a second hydraulic fluid flow line, a first actuator port hydraulically coupled to one of the head side or rod side of the hydraulic actuator by a third hydraulic fluid flow line, a second actuator port hydraulically coupled to one of the head side or rod side of the hydraulic actuator by a fourth hydraulic fluid flow line, a dual power activation port hydraulically coupled to a source of hydraulic pressure, and a tank port hydraulically coupled to a tank;
wherein, when the mode-switching valve is in the first position and the motion control unit is in a first configuration, the hydraulic power source fluidly connects to the second port through the dual power activation port and the second pump/motor port, the first port fluidly connects to one of the head side or rod side of the hydraulic actuator through the first pump/motor port and the second actuator port, and one of the head side or rod side of the hydraulic actuator fluidly connects to the tank through the first actuator port and the tank port;
wherein, when the mode-switching valve is in the second position and the motion control unit is in a second configuration, the hydraulic power source fluidly connects to the second port through the dual power activation port and the second pump/motor port, the first port fluidly connects to one of the head side or the rod side of the hydraulic actuator through the first pump/motor port and the first actuator port, and one of the head side or rod side of the hydraulic actuator fluidly connects to the tank through the second actuator port and the tank port; and
wherein, when the mode-switching valve is in the third position and the motion control unit is in a third configuration, the first port fluidly connects to one of the head side or rod side of the hydraulic actuator through the first pump/motor port and the first actuator port, the second port fluidly connects to one of the head side or the rod side of the hydraulic actuator through the second pump/motor port and the second actuator port, and the hydraulic power source and the tank are respectively isolated from the head side and the rod side of the hydraulic actuator at the dual power activation port and the tank port, wherein the hydraulic power source is isolated from the hydraulic actuator at the dual power activation port and the tank is isolated from the hydraulic actuator at the tank port.
2. The motion control device of claim 1 , wherein the electric motor/generator electrically connects to the electrical power source and is mechanically coupled to the hydraulic pump/motor.
3. The motion control device of claim 2 , wherein the electric motor/generator is mechanically coupled to the hydraulic pump/motor by a drive shaft.
4. The motion control device for powering a hydraulic actuator of claim 1 , further comprising a first load holding valve and a second load holding valve, wherein the first load holding valve and the second load holding valve are positioned downstream of the mode-switching valve relative to the hydraulic pump/motor, wherein the first load holding valve is configured to selectively close and hydraulically lock the hydraulic actuator at the rod side, wherein the second load holding valve is configured to selectively close and hydraulically lock the hydraulic actuator at the head side.
5. The motion control device for powering a hydraulic actuator of claim 1 , wherein the hydraulic power source is a pressure rail.
6. The motion control device for powering a hydraulic actuator of claim 1 , wherein the hydraulic power source is an accumulator.
7. The motion control device for powering a hydraulic actuator of claim 1 , further comprising a first check valve and a second check valve, wherein the hydraulic power source is configured to supply power to the rod side of the hydraulic actuator through the first check valve, wherein the hydraulic power source is configured to supply power to the head side of the hydraulic actuator through the second check valve.
8. The motion control device for powering a hydraulic actuator of claim 1 , wherein, when the mode-switching valve is in the first position and the motion control unit is in a first configuration, the first port fluidly connects to the head side of the hydraulic actuator and the rod side of the hydraulic actuator fluidly connects to the tank.
9. The motion control device for powering a hydraulic actuator of claim 1 , wherein, when the mode-switching valve is in the second position and the motion control unit is in a second configuration, the first port fluidly connects to the rod side of the hydraulic actuator and the head side of the hydraulic actuator fluidly connects to the tank.
10. The motion control device for powering a hydraulic actuator of claim 1 , wherein, when the mode-switching valve is in the third position and the motion control unit is in a third configuration, the first port fluidly connects to the rod side of the hydraulic actuator and the second port fluidly connects to the head side of the hydraulic actuator.