| In the hydraulic system, as the main control elements, hydraulic valves regulate the oil pressure, flux and flow direction by means of controlling their opening size and on-off so as to realize various motions of executive components. Properties of the hydraulic valves play an important role in the system performance. The slide valves are the most commonly-used structure, as they are simple in work principle, convenient in processing and assembling, precise in motion and small in frictional resistance. Dimensional, shape and position error during processing and assembling and oil pollution can result in breakdown of leakage and clamping in the hydraulic valves, and then decrease their reversing precision, stationary and reliability and so on.This paper mainly studies the mechanism of the leakage and clamping in the slide valves, finds out the main influence factors such as temperature, pressure, sealing length, oil pollution and so on. Mathematical models of the leakage and clamping force are deduced and established at last.Secondly, finite element models of clearance seals are established and simulated by Fluent. Effects of balance grooves with different shapes, numbers and parameters on spools are simulated. At the same time, clamping caused by oil pollution is simulated by means of multiphase flow. Then effects of particle size and volume concentration on clamping are analyzed quantitatively and some certain measures are put forward.Lastly, orthogonal tests are designed aimed at leakage. Finite element models of clearance seals are established based on orthogonal tests and simulated by Fluent. What’s more, hydraulic test bed is designed to carry out tests to verify the simulation results. Simulations by Fluent are verified to be accurate and applicable by contrastive analysis between simulation and tests. Then tendency and rule of factors and the best parameters are obtained. |
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