Updated: Aug 26, 2018
Why does the hydraulic final drive motor creep at low speeds?
First, the final drive motors’ magnitude of the friction is unstable. The ordinary frictional force is increased as the speed becomes larger, but the frictional resistance inside the motor that operates in the stationary and low-speed regions does not increase, but decreases, and becomes a resistance when the working speed is increased. On the other hand, the hydraulic travel motors and the load are pushed by the pressure rise after being compressed by the hydraulic mooring.
Second, the amount of final drives leakage is unstable. The leakage of the hydraulic motor is not the same every moment, it is periodically fluctuated with the change of the phase angle of the rotor. Because the flow rate into the hydraulic motor is relatively small at low speeds, the proportion of leakage is relatively large, and the instability of the leakage will significantly interfere with the flow value of the motor operation, so the speed is unstable.