Patent ID: 6966180
Filing Date: 2005-11-22
Classification: F04B,F15B,F16H

Abstract:
1. A control arrangement for a hydraulic system, comprising a variable throughput hydraulic pump connected with a hydraulic motor by a supply line and a return line for transfer of working fluid, and a pump controller mechanism adapted to vary the throughput of said pump, the pump driving the motor in a traction operation mode and the motor driving the pump in a braking mode wherein said control arrangement includes a first feedback element which provides to said pump controller mechanism first feedback of a temperature of the working fluid, said pump controller mechanism being adapted to vary the throughput of said pump in response to said feedback, wherein the pump controller mechanism is adapted to reduce the throughput of the pump when the temperature of the working fluid exceeds a first temperature, wherein said first feedback element is a temperature sensor for sensing the temperature of the working fluid and wherein the pump controller mechanism is adapted to reduce the throughput of the pump by a first amount when an output of the temperature sensor indicates that the working fluid has first exceeded the first temperature, wherein the pump controller mechanism is adapted to reduce the throughput of the pump by a second amount when the temperature of the working fluid does not drop below the first temperature after a first predetermined time period.