Hydraulic systems utilizing combination open- and closed-loop pump systems

摘要

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.

主权项

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; and a 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; and a 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.