초록 ▼

A pump system includes a closed-loop fluid circuit and an open-loop fluid circuit. The closed-loop fluid circuit includes a motor for rotating a first component connected to the closed-loop fluid circuit. A closed-loop pump drives the motor up to a first maximum rotational speed. The open-loop fluid

A pump system includes a closed-loop fluid circuit and an open-loop fluid circuit. The closed-loop fluid circuit includes a motor for rotating a first component connected to the closed-loop fluid circuit. A closed-loop pump drives the motor up to a first maximum rotational speed. The open-loop fluid circuit includes an open-loop pump for driving a second component connected to the open-loop fluid circuit. A control circuit includes a control valve for switching the outflow from the open-loop pump. The control valve selectively connects the open-loop pump to the closed-loop fluid circuit and simultaneously disconnects the open-loop pump from the open-loop fluid circuit. When the open-loop pump is connected to the closed-loop circuit, the closed-loop pump and the open-loop pump drive the motor at a second rotational speed greater than the first maximum rotational speed.

대표청구항 ▼

1. A pump system comprising: a closed-loop fluid circuit comprising: a motor for rotating a first component connected to the closed-loop fluid circuit;a closed-loop pump for driving the motor at a first maximum rotational speed; and an open-loop fluid circuit comprising an open-loop pump for driving

1. A pump system comprising: a closed-loop fluid circuit comprising: a motor for rotating a first component connected to the closed-loop fluid circuit;a closed-loop pump for driving the motor at a first maximum rotational speed; and an open-loop fluid circuit comprising an open-loop pump for driving a second component connected to the open-loop fluid circuit that provides an auxiliary function; anda control circuit comprising: a control valve for selectively connecting the open-loop pump to the closed-loop fluid circuit and for selectively disconnecting the open-loop pump from the closed-loop fluid circuit, wherein when the open-loop pump is connected to the closed-loop circuit, the closed-loop pump and the open-loop pump drive the motor at a second maximum rotational speed greater than the first maximum rotational speed; anda controller connected to each of the closed-loop pump, the open-loop pump, the motor, and the control valve, wherein the controller sends a control signal to actuate the control valve so as to connect the open-loop pump to the closed-loop fluid circuit when the controller receives a first component speed signal corresponding to a desired first component speed that is in excess of a first component speed produced when the closed-loop pump is at the first maximum rotational speed and wherein the auxiliary function of the open-loop fluid circuit is disabled when the open-loop pump is connected to the closed-loop fluid circuit. 2. The pump system of claim 1, wherein the closed-loop fluid circuit further comprises a control spool for controlling a direction of rotation of the closed-loop pump, such that when the control spool is in a first position, an output flow from the closed-loop pump is directed in a first direction through the closed-loop circuit. 3. The pump system of claim 2, wherein the control circuit further comprises a shuttle valve system for controlling an output flow from the open-loop pump, such that when the open-loop pump is connected to the closed-loop circuit and when the shuttle valve system is in a first position, the output flow from the open-loop pump is directed in the first direction through the closed-loop circuit. 4. The pump system of claim 1, further comprising a charge pump for filling the closed-loop fluid circuit with a hydraulic fluid. 5. The pump system of claim 4, further comprising a common motor for driving each of the open-loop pump, the closed-loop pump, and the charge pump. 6. The pump system of claim 3, wherein the shuttle valve system comprises a shuttle valve. 7. The pump system of claim 3, wherein the shuttle valve system comprises at least one of a plurality of hydraulic piloted valves and a plurality of electronic solenoid operated valves. 8. The pump system of claim 1, wherein each of the closed-loop pump and the open-loop pump comprise variable displacement pumps. 9. The pump system of claim 1, wherein the control valve comprises a manual valve. 10. A transit mixer comprising the pump system of claim 1, wherein the first component comprises a drum. 11. A method of controlling a pump system comprising a closed-loop fluid circuit comprising a closed-loop variable displacement pump, an open-loop fluid circuit comprising an open-loop variable displacement pump, a control valve, and a controller, the method comprising: adjusting an output flow of the closed-loop variable displacement pump based on a first desired speed signal received by the controller; andactuating the control valve so as to connect the open-loop variable displacement pump to the closed-loop fluid circuit based on a second desired speed signal received by the controller,wherein an auxiliary function of the open-loop fluid circuit is disabled when the open-loop variable displacement pump is connected to the closed-loop fluid circuit. 12. The method of claim 11, further comprising increasing an output flow of the open-loop variable speed pump based on a third speed signal received by the controller. 13. The method of claim 12, further comprising reducing the output flow of the open-loop variable displacement pump based on a fourth desired speed signal received by the controller. 14. The method of claim 11, further comprising changing an output flow direction from the closed-loop variable displacement pump based on a desired direction signal received by the controller. 15. The method of claim 14, further comprising changing a position of a shuttle valve at an outlet of the open-loop variable displacement pump based on the desired direction signal received by the controller. 16. The method of claim 11, further comprising charging the closed-loop fluid circuit with hydraulic fluid. 17. A pump system comprising: a closed-loop fluid circuit comprising: a motor for rotating a first component connected to the closed-loop fluid circuit; anda closed-loop pump for driving the motor at a first maximum rotational speed;an open-loop fluid circuit comprising an open-loop pump for driving a second component connected to the open-loop fluid circuit; anda control circuit comprising: a control valve for selectively connecting and disconnecting the open-loop pump with respect to the closed-loop fluid circuit, wherein when the open-loop pump is connected to the closed-loop circuit, the closed-loop pump and the open-loop pump are adapted to drive the motor at a second maximum rotational speed greater than the first maximum rotational speed;wherein the closed-loop fluid circuit further comprises a control spool for controlling a direction of rotation of the closed-loop pump, such that when the control spool is in a first position, an output flow from the closed-loop pump is directed in a first direction through the closed-loop circuit; andwherein the control circuit further comprises a shuttle valve system for controlling an output flow from the open-loop pump, such that when the open-loop pump is connected to the closed-loop circuit and when the shuttle valve system is in a first position, the output flow from the open-loop pump is directed in the first direction through the closed-loop circuit. 18. The pump system of claim 17, wherein when the control spool is in a second position, the output flow from the closed-loop pump is directed in a second direction through the closed-loop circuit, wherein when the open-loop pump is connected to the closed-loop circuit and when the shuttle valve system is in a second position, the output flow from the open-loop pump is directed in the second direction through the closed-loop circuit, and wherein the control spool and the shuttle valve system are coordinated so that the closed-loop pump and the open-loop pump direct flow in the same direction through the closed-loop circuit. 19. The pump system of claim 17, wherein the shuttle valve system comprises a shuttle valve. 20. The pump system of claim 17, wherein the shuttle valve system comprises at least one of a plurality of hydraulic piloted valves and a plurality of electronic solenoid operated valves.