Patent 7726125 was granted and assigned to Caterpillar Inc. on June, 2010 by the United States Patent and Trademark Office.
A hydraulic circuit is disclosed. The hydraulic circuit may have a variable displacement pump. The variable displacement pump may have a fluidic displacement control configured to vary a flow of pressurized fluid based on a fluid signal and an electronic displacement control configured to vary the flow of pressurized fluid based on an electronic signal. The flow of pressurized fluid may be controlled by the one of the fluidic and electronic displacement controls that requests the smallest flow of pressurized fluid. The hydraulic circuit may also have a control valve connected between the pump and the fluidic displacement control, and the control valve may be configured to transmit the fluid signal to the fluidic displacement control. The hydraulic circuit may further have a controller configured to transmit a fluid signal to cause the fluidic control to request a maximum flow of pressurized fluid, and transmit an electronic signal requesting a flow smaller than the maximum flow, which causes the electronic displacement control to vary the flow of pressurized fluid.