Patent ID: 9403434
Filing Date: 2016-08-02
CPC Classification: B60K,F15B,F16H

Claim Text:
1. A method of operating a hydraulic system and comprising a variable displacement pump, a hydraulic fluid having a temperature and at least one actuating assembly comprising an actuator operated by a control valve, the method comprising: when the fluid temperature is below a low temperature, operating the control valve open center while the variable displacement pump provides a constant flow of hydraulic fluid to the control valve; when the fluid temperature is between said low temperature and a moderate temperature above said low temperature, operating the control valve open center while the variable displacement pump provides at least a minimum flow of hydraulic fluid to the control valve, wherein said minimum flow decreases with an increase of the fluid temperature; and when the fluid temperature is above said moderate temperature, operating the control valve closed center while maintaining at least a system pressure at the control valve when in neutral and wherein the variable displacement pump provides hydraulic fluid to the actuator when the control valve is actuated.