High Pressure and Large Flow Hydraulic System Powered by Dual Pump and Servo Motor

Author(s):  
Jun Gao ◽  
Yujia Kang ◽  
Xuemei Liu ◽  
Chun Zhang
2014 ◽  
Vol 1044-1045 ◽  
pp. 930-932
Author(s):  
Yu Ping Wei

The operating system of loader working device is composed of the boom and bucket. It is operated mainly through multi-way valve axis manipulation, this kind of way is force-large, labor-intensive, but is low efficient. So it is necessary to optimize the oil source valve. Using the hydraulic pilot to control loader multi-way valve to optimize in the loader is safe, comfortable, furnished spirit and can achieve variable speed. Working hydraulic system uses a small flow pilot circuit control. The main oil is controlled by high pressure and large flow, and then the operating force of the working device is reduced greatly.


2013 ◽  
Vol 303-306 ◽  
pp. 1786-1789 ◽  
Author(s):  
Xiang Lin Liu ◽  
Xiao Feng He ◽  
Long Jun Luo ◽  
Xiao Hui Luo

The use of electromagnetic relief valve with high pressure and large flow rate in hydraulic system is usually easy to bring vibration and noise issues, especially while water or high water based fluid (HWBF) is used as the fluid medium. In this paper, a HWBF electromagnetic relief valve with a cushion valve was presented and its simulation model was built based on AMESim software. Through simulation, it is found that the cushion valve can significantly reduce the peak pressure gradient of the electromagnetic relief valve during unloading process compared with that without a cushion valve. This research provides a new solution for solving the vibration and noise issues of a hydraulic system with electromagnetic relief valve.


Author(s):  
Xiaofu Zhang ◽  
Guanglin Shi

This article presents a composite adaptive control method to improve the position-tracking performance of an electro-hydraulic system driven by dual constant displacement pump and dual servo motor named as a novel electro-hydraulic system with unknown disturbance. A composite adaptive controller based on backstepping method is designed to estimate the uncertainties of electro-hydraulic control system, including the damping coefficient and elastic modulus. In order to release the persistent excitation condition of conventional adaptive control, which is often infeasible in practice, a prediction error based on the online historical data is used to update the estimated parameters. Furthermore, a disturbance observer is used to estimate the disturbance including the unmeasurable load force, friction and other unmodeled disturbance. The experiment results are provided and compared with other methods to verify the effectiveness of the proposed method, and the results have indicated that the proposed method has a better position-tracking performance with the convergent estimated parameters.


Machines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 37
Author(s):  
Heng Zhang ◽  
Yaoyao Liao ◽  
Ze Tao ◽  
Zisheng Lian ◽  
Ruihao Zhao

In the field of fully mechanized coal mining equipment, the hydraulic valve used in the hydraulic support is an on/off directional valve. There are many problems caused by the valve such as large pressure shock and discontinuous flow control. Therefore, a novel two-position three-way hydraulic proportional valve suitable for high-pressure and large-flow conditions is proposed to overcome the above problems. The novel valve utilizes a two-stage structure and the displacement follow-up principle is adopted between the pilot stage and the main stage to meet proportional control. In this paper, a simulation model of the novel proportional valve was established after a simplified analysis of the structural principle. Its reliability and the feasibility of the design were verified by the test results under different working conditions. Then, the step response characteristics of the proportional valve under different strokes were predicted and analyzed. Nonlinear characteristics were presented, and the closing time was shorter than the opening time because of the influence of nonlinear flow force. Under different ramp signals, the displacement of the main inlet spool was always approximately equal to the displacement of the pilot stage. Then, the motion relationship between the pilot stage and the main stage was studied, and the influence of the structural parameters on the stability was analyzed.


2011 ◽  
Vol 341-342 ◽  
pp. 452-455
Author(s):  
Liang Yuan Shen ◽  
Hong Guang Wang ◽  
Rui Jun Zhang ◽  
Peng Peng Liu

The usual hydraulic pump station pumps the general use of quantitative supply voltage level or constant pressure, using the corresponding control valve speed to adapt to work requirements, when the hydraulic system is intermittent or low-load condition, a large number of high-pressure oil through regulator overflow Back to the tank overflow valve, causing a great deal of energy consumption, when the hydraulic system requires a large flow of oil, it will result in a short time for the fluid system for liquid inadequate and under-voltage phenomenon. To solve this problem, we propose to improve the program, and conducted the analysis and comparison of several options to determine the source of energy-saving adaptive overall scheme of oil, its reasonable design, implementation of the automatic adaptive functioning, energy loss Small, the effect is significant.


Author(s):  
Lixia Gao ◽  
Jie Yang ◽  
Zilong Jiang ◽  
Jianzhong Ma ◽  
Song Li

In this paper, the Flow Induced Vibration (FIV) tests of heat transfer helical tube bundle have been carried out. The results show that the more large flow velocity in tube becomes, the more high pressure drop of bundle is. The dynamic buckling of bundle does not occur during steady-state operation. The fatigue evaluation has been done according to ASME code and the structure is founded to satisfy the ASME code requirements.


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