2A1-D03 Development of the durability servo valve for water hydraulic system(Mechanism and Control for Actuator (1))

SUMMARY In this paper, mathematical models of kinematics, statics and inverse dynamics are derived firstly according to the mechanical structure of leg hydraulic drive system (LHDS). Then, all the above models are integrated with MATLAB/Simulink to build the LHDS simulation model, the model not only considers influence of leg dynamic characteristics on hydraulic system but also takes into account nonlinearity, variable load characteristics and other common problems brought by hydraulic system, and solves compatibility and operation time which brought by using multiple software simultaneously. The experimental results show the simulation model built in this paper can accurately express characteristics of the system.

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Damping of Self-Excited Pressure Pulsations in Petrodiesel Pipeline

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.630.375 ◽

2014 ◽

Vol 630 ◽

pp. 375-382 ◽

Cited By ~ 3

Author(s):

Daniel Himr ◽

Vladimir Haban

Keyword(s):

Hydraulic System ◽

Check Valve ◽

Control Valve ◽

Sampling Frequency ◽

Pressure Pulsations ◽

One Dimensional ◽

Fuel Storage ◽

Excited Oscillation ◽

Subsequent Measurement ◽

And Control

A pumping station in a fuel storage suffered from pressure pulsations in a petrodiesel pipeline. Check valves protecting the station against back flow made a big noise when disc hit a seat. Due to employees complaints we were asked to solve the problem, which could lead to serious mechanical problems. Pressure measurement in the pipeline showed great pulsations, which were caused by self-excited oscillation of control valves at the downstream end of pipeline. The operating measurement did not catch it because of too low sampling frequency. One dimensional numerical model of the whole hydraulic system was carried out. The model consisted of check valve, pipeline and control valve, which could oscillate, so it was possible to simulate the unsteady flow. When the model was validated, a vessel with nitrogen was added to attenuate pressure pulsations. According to the results of numerical simulation, the vessel was installed on the location. Subsequent measurement proved noticeably lower pulsations and almost no noise.

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Research on the Impact Pressure of the Hydraulic Rolling-Cut Shear

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.145.410 ◽

2010 ◽

Vol 145 ◽

pp. 410-413 ◽

Cited By ~ 3

Author(s):

Jing Wang ◽

He Yong Han ◽

Qing Xue Huang ◽

Jun Wang

Keyword(s):

Hydraulic System ◽

Impact Pressure ◽

Direct Impact ◽

Actual Situation ◽

Work Situation ◽

Servo Valve ◽

Indirect Impact ◽

Hydraulic Servo ◽

Hydraulic Servo System ◽

The Impact

The reasons for impact pressure are obtained by the research the hydraulic system of Hydraulic Rolling-Cut Shear. The impact pressure of hydraulic system is divided into direct impact and indirect impact. Based on analyzing the actual situation the measures should be taken to reduce the impact pressure when design hydraulic system. The suitable length of pipeline can improve the performance of the hydraulic system because the length is important for the impact pressure. The accumulator can absorb impact pressure and improve the work situation of servo valve. Therefore, the suitable accumulators should be set in the hydraulic system. The study provides theory basis for the pipe design of large hydraulic servo system.

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