Patent ID: 8234860
Filing Date: 2012-08-07
Classification: E02F,F04B,F15B

Abstract:
1. A machine control system, comprising: a pump driven to pressurize fluid, the pump being driven by an engine to pressurize the fluid; a low pressure reservoir; at least one actuator connected to receive fluid pressurized by the pump and discharge fluid to the low pressure reservoir; a bypass passage situated to allow fluid pressurized by the pump to bypass the at least one actuator and flow to the low pressure reservoir; a warmup valve disposed within the bypass passage and being movable between a flow-passing position and a flow-blocking position; a hydraulic temperature sensor configured to generate a signal indicative of a temperature of the fluid; and a controller in communication with the pump, the warmup valve, and the hydraulic temperature sensor, the controller being configured to move the warmup valve to the flow-passing position, fix a displacement position of the pump, and adjust an input speed of the pump in response to the signal only after a temperature of the engine has increased to a desired engine temperature or the engine has driven the pump for a period of time.