Applied Mechanics and Materials Vol. 779

Abstract: The pair between slipper and swash-plate is an important friction pair in the axial piston pump. Due to quick relative velocity, alternating load, numerous slippers, and high contact pressure between the friction surfaces, the wear-out and fatigue failure constantly occurs, which is one of the key factors affecting reliability of the piston pump. It is of fundamental significance to investigate the mechanism of slipper power loss and to find an appropriate method to improve the lubrication of the slipper. Here, the model of friction power loss between slipper and swash-plate is established, and the friction power loss between slipper and swash-plate is solved and comparatively analysed. Finally, the correctness of theoretical analysis and simulation results are verified by experiments.

Abstract: When designing the servo valve with different structure parameters, the influence of the interaction between the liquid and the solid on the performance of servo valve can only be obtain by the method of experiment, and then it can increase the time and cost of designing the servo valve. The liquid-solid couple method can obtain the influence of structure parameters on the performance of servo valve under the circumstance of reducing the experimental cost and time. The paper chooses the servo valve of A and B as models for study, The text adopts FSI method to analyze the flow field of double nozzle baffle electro-hydraulic servo valve prestage through the software of ANSYS, research the change of the prestage flow field by deflection of loaded armature baffle components, contrast and analyze the change of velocity, pressure, power loss and flow coefficient of fixed choke, nozzle, return port, and the displacement of the valve core of slide valve, stress of armature baffle components, pressure at both ends of spool. Summarize the advantages and disadvantages of A and B servo valve, and find different parameters of servo valve have different performance, it is difficult to find a common structure and size. It can help us to select the requirement structure by using fluid-structure interaction, reduce experiments and save cost.

Abstract: While axial piston pump is the core component of hydraulic system, its service life and reliability depend much on the selection of materials, friction pairs and process parameters. To identify these factors, wear condition of friction pair is conducted by using MWF-10 wear rig. Based on ANOVA of Taguchi Method,the influences of surface roughness and hardness on wear loss and friction coefficient are compared. In addition, the results show that the optimal friction pair and surface roughness of hard specimens have influence mostly on the wear loss and the friction coefficient.

Abstract: A double-action three-stage synchronous expanding and contracting hydraulic cylinder has been designed based on the principle of synchronous expanding and contracting hydraulics cylinder. The Principle of linear synchronous expanding and contracting hydraulics cylinder and the main points of design have been discussed. Modeling and simulation are conducted in AMESim system and the result shows that the multi-stage cylinder can expand and contract synchronously and smoothly. As long as the effective area is proportional, the multi-stage cylinder can move linearly.

Abstract: Aiming at the problems of cavitation noise in the cone throttle valve, triangle groove cone throttle valves with 45, 53, 60 degree were selected as the research objects. Firstly the structure characteristics of the throttle valves were analyzed, then the three-dimensional models and mathematical models were established. By using the finite element simulation software ADINA, the simulation diagrams about pressure and flow velocity of the cone valves were obtained and then verified on the test bench which was about the noise characteristics of throttle valve. The investigation result showed that the flow field of the cone valve was complex, and there were local low pressure areas where were high incidence of cavitation; the valve with 60 degree spool had the minimum noise, which showed the best performance, then the 53 degree spool was a bit poor, and the worst valve was 45 degree spool. Increasing the angles of the triangle groove appropriately could reduce the cavitation noise and improve the performance of the valve. This investigation has great significance on understanding the flow field and controlling the cavitation noise in triangle groove cone throttle valves. Besides it also has a certain reference value to other hydraulic components on the cavitation noise control and structural optimization.

Abstract: This paper presents the parameters and assumptions of the hydrostatic guide rail in both ideal and actual working conditions, the simulate calculation of fluid-solid heat coupling field between gas film and the bearing surface is finished by Fluent based on finite volume method. By analyze and compare the results after post-treatment, we gain the effects caused by guide way’s structure and deformation on the formation of film pressure field, temperature field inside gas film, besides this paper also provides relate conclusions.

Abstract: Valve orifice is the common place that the cavitation easily occurs in the hydraulic systems. This paper introduces a criteria to estimate the inception of the cavitation of the V-type valve orifice with the stress state. Based on this criteria, a cavitation model which considers the dynamics of the cavity and incompressible gas is proposed to analyze the pressure, stress and the cavitation distribution of the phase in the V-type orifice. The distributions of the cavitation along the axis and the cross section are analyzed. The simulation results show that the cavitation is easily occurred in the downstream just after the orifice and the bubbles are mostly gathered in the top of the cross section which is vertical to the axis of the flow field. The simulation results is reasonable according to the facts. Accordingly, the cavitation of the V-type orifice is predicted reasonably. The research and results of this paper are useful for the design of the hydraulic valves.

Abstract: Plunger pair of plunger water hydraulic motor has the problem of leakage. Simulation of the leakage of plunger pair of plunger water hydraulic motor is carried out. Through calculation and analysis establish the model of plunger pair of plunger water hydraulic motor. The simulation analysis of leakage of plunger pair was carried out with Fluent software. Theoretical calculation and simulation results of plunger pair are obtained. The results provide basis and method to reduce the leakage of plunger water hydraulic motor and design for the motor plunger.

Abstract: In the situation of high-speed or heavy load, pneumatic cylinders usually generate cushion failure like collision or rebound, so that the key question to be solved for the cylinders is cushion. In order to obtain a better cushion method, the paper used the ideal cushion characteristic curve of hydraulic cylinders for reference; and throttling area equation, temperature equation, flow rate equation and motion equation were established. By building the simulation module in Matlab/Simulink, the rule of throttling area approaching to the ideal cushion curve was found, which provide theoretical basis for the design of cylinders cushion devices.