Static and dynamic performance improvement of a hydraulic feedback valve for load control by introducing force feedback and compensation orifice

This paper presents two methods for the static and dynamic performance improvement of a hydraulic feedback valve for load control. Firstly, by introducing force feedback between the pilot and main spools, the control stroke is widened, which means the static flow control performance is enhanced. Secondly, by introducing a compensation orifice to the pilot spool, a damping effect appears and the oscillations and overshoot in the opening process of the pilot spool are eliminated, which means the dynamic performance is improved. Mathematical analysis and simulations were conducted to achieve optimized parameters of the feedback spring and compensation orifice. An actual valve was built according to the above methods and optimized parameters. The good static and dynamic performance of the valve in the tests on a specially designed test rig indicates that the proposed methods can provide theoretical guidance for hydraulic feedback valve design.