scholarly journals Resonance Analysis of High-Frequency Electrohydraulic Exciter Controlled by 2D Valve

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Guojun Pan ◽  
Yan Ren ◽  
Jian Ruan
Keyword(s):  
Hydraulic System ◽  
Block Diagram ◽  
Load Flow ◽  
Resonant Peak ◽  
Load Pressure ◽  
Classical Fluid ◽  
Resonance Analysis ◽  
Fluid Theory ◽  
Oil Source ◽  
Resonant Characteristic

The resonant characteristic of hydraulic system has not been described yet because it is necessarily restricted by linear assumptions in classical fluid theory. A way of the resonance analysis is presented for an electrohydraulic exciter controlled by 2D valve. The block diagram of this excitation system is established by extracting nonlinear parts from the traditional linearization analysis; as a result the resonant frequency is obtained. According to input energy from oil source which is equal to the reverse energy to oil source, load pressure and load flow are solved analytically as the working frequency reaches the natural frequency. The analytical expression of resonant peak is also derived without damping. Finally, the experimental system is built to verify the theoretical analysis. The initial research on resonant characteristic will lay theoretical foundation and make useful complement for resonance phenomena of classical fluid theory in hydraulic system.

Oil Source Valve Optimized Design and its Application in Mechanical Loader

2014 ◽  
Vol 1044-1045 ◽  
pp. 930-932
Author(s):  
Yu Ping Wei
Keyword(s):  
Operating System ◽  
High Pressure ◽  
Hydraulic System ◽  
Optimized Design ◽  
Variable Speed ◽  
Small Flow ◽  
Oil Source ◽  
Working Device ◽  
Large Flow

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.

Addressing Valves With Pressure Ripple

2018 ◽  
Author(s):  
Ryan J. Foss ◽  
Mengtang Li ◽  
Eric J. Barth ◽  
Kim A. Stelson ◽  
James D. Van de Ven
Keyword(s):  
Hydraulic System ◽  
Experimental Validation ◽  
Resonant Peak ◽  
Elastic Membrane ◽  
System Parameters ◽  
System Validation ◽  
System Pressure ◽  
Pressure Ripple ◽  
Specific Frequency ◽  
Linear And Nonlinear

Pressure ripple can be purposely used to transmit information within a hydraulic system. For example, introducing ripple at specific frequencies into a fluid line can activate a valve, eliminating electrical wires. A key element of this system is the hydraulic resonator that activates the valve when a specific frequency pressure ripple is present in the line. This paper presents a linear and nonlinear model of the hydraulic resonator with experimental validation. The hydraulic resonator consists of an inertance tube, a series capacitor, made up of a deforming elastic membrane, and an orifice. For system validation, displacement of a valve, the capacitor, and system pressure are measured. The model was effective at predicting the natural frequency of the system and the narrowness of the resonant peak. Different effects were also shown experimentally by changing the fluid’s viscosity and system parameters.

A study of function-based diagnosis strategy and testability analysis for a system

2011 ◽  
Vol 226 (1) ◽  
pp. 273-282 ◽  
Author(s):  
Y-T Tsai ◽  
Y-Y Hsu
Keyword(s):  
Hydraulic System ◽  
Block Diagram ◽  
Fault Isolation ◽  
Functional Block Diagram ◽  
Diagnostic Ability ◽  
System A ◽  
Study Results ◽  
System Maintenance ◽  
System Information ◽  
Test Points

A good diagnostic policy can not only shorten the detection time of faults but also improve the effectiveness of system maintenance. This paper presents a function-based diagnosis strategy that provides a helpful methodology for fault identification. The diagnosis trees of the systems are constructed based on a functional block diagram consisting of function elements (FEs) and test points (TPs). The correlations between the FEs and the TPs are first analysed according to system information flows. Two weighted indexes for fault detection and fault isolation are defined to determine the priority of these TPs in testing. Several parameters related to diagnostic ability are also introduced to provide an evaluated approach for system testability. The diagnostic steps and costs between traditional sequential testing and the function-based diagnosing are compared. The study results may be useful in planning diagnosis actions and testability design for a system. A hydraulic system is used as an example in order to depict the proposed methods.

Energy-Saving Optimization for Wheel Loader's Double-Pump Confluence Hydraulic System with Fixed-Displacement Pump

2013 ◽  
Vol 389 ◽  
pp. 618-622 ◽  
Author(s):  
Zhao Jun Tan ◽  
Yao Jin
Keyword(s):  
Field Test ◽  
Hydraulic System ◽  
Test Results ◽  
Proportional Valve ◽  
Load Pressure ◽  
Wheel Loader ◽  
Displacement Pump ◽  
Operation Rule ◽  
Constant Displacement ◽  
Simulation Results

The field test results show that existing double-pump confluence hydraulic system with constant displacement pump of wheel loader could only save some energy while the load pressure is rather high (>15Mpa in the tests). However, the load pressure is usually low, especially when the wheel Loader is working on bulldozing operation or just steering and running. Thus, an optimized double-pump confluence hydraulic system was designed by adding a proportional valve and adjust operation rule, so that the output oil of steering pump flow into tank by the proportional valve while the load pressure is low and the relative position of joystick is not large (<72%), and in this way the throttle losses is reduced. Simulation results indicate that the optimized confluence hydraulic system could save 26.2% throttle losses while the wheel Loader is working on bulldozing operation.

scholarly journals VARIABILITY MANAGEMENT OF EFFICIENT VEHICLE OPERATION BASED ON FUNCTIONAL RESONANCE ANALYSIS METHOD

2021 ◽  
pp. 80-88
Author(s):  
O.P. SAKNO ◽  
T.M. KOLESNIKOVA
Keyword(s):  
Traffic Safety ◽  
Block Diagram ◽  
Good Condition ◽  
Technical Condition ◽  
Technical System ◽  
Analysis Method ◽  
Resonance Analysis ◽  
Maintenance Work ◽  
Technical Operation ◽  
Definition Of

Raising of problem. The methodology presented in this study is aimed at modeling the variability of the technical condition when operating a car in a complex social and technical system "car − person − environment". This allows you to simulate the change in the operational properties of the car depending on its operation, affecting the change in the technical condition by the Functional Resonance Analysis Method (FRAM). Purpose. The variability of the technical operation of the car needs to be managed, and not reduced or eliminated, since this is an advantage, as well as conditions for the safety and functioning of complex socio-technical systems. To control it, you must first monitor the variability of the vehicle's technical operation. A set of relevant indicators needs to be identified and developed. Their interpretation makes it possible to draw conclusions about the level of technical condition, operational properties of the vehicle and traffic safety and supports the prediction of the occurrence of future events (failure occurrence). Conclusion. Thus, the basic principles of the FRAM for modeling the variability of the technical condition when operating a car in a complex social and technical system "car − person − environment" have been determined. The relationship has been established between the definition of traffic safety, the FRAM model and the performance indicators of the vehicle. The developed model of the FRAM for maintenance of the undercarriage of cars, consisting of a set of functions that describe the actions taken to maintain cars to ensure their good condition. A block diagram of the implementation of functionally oriented technologies for the maintenance and repair of cars has been developed, taking into account the design features and the level of technology for technical influences. This allows you to objectively determine the required scope of maintenance work, depending on the results of diagnostics and the availability of technological equipment.

Research Regarding Pressure Compensated Flow Control Valves

2015 ◽  
Vol 809-810 ◽  
pp. 992-997
Author(s):  
Irina Tiţa ◽  
Irina Mardare
Keyword(s):  
Power Systems ◽  
Flow Control ◽  
Hydraulic System ◽  
Block Diagram ◽  
Control Valve ◽  
Operating Conditions ◽  
Flow Control Valve ◽  
Constant Flow ◽  
Working Pressure ◽  
Displacement Pump

In fluid power systems, flow control may be done either with variable displacement pump or using variable orifice. In this paper is considered the second method for flow control. In a hydraulic system, working pressure is frequently variable and therefore the use of the method does not provide constant flow rates in all operating conditions. In order to keep a constant flow, if this is important in a certain case, the flow control must be accomplished using a pressure compensated flow control valve. In this paper are analyzed possible structural diagrams, mathematical model, block diagram and functional diagram for this kind of equipment. The influence of the spring compression is analyzed also. The diagrams proposed in the paper will be used for the study of a hydraulic system designated for applications with strict flow control. It will represent an important research instrument for such cases.

Improvements in Fixed-Valve Micropump Performance Through Shape Optimization of Valves

2004 ◽  
Vol 127 (2) ◽  
pp. 339-346 ◽  
Author(s):  
Adrian R. Gamboa ◽  
Christopher J. Morris ◽  
Fred K. Forster
Keyword(s):  
Shape Optimization ◽  
Dynamic Model ◽  
Flow Resistance ◽  
Load Flow ◽  
Maximum Output ◽  
Load Pressure ◽  
Pump Design ◽  
Number Range ◽  
Forward Flow ◽  
Linear Dynamic

The fixed-geometry valve micropump is a seemingly simple device in which the interaction between mechanical, electrical, and fluidic components produces a maximum output near resonance. This type of pump offers advantages such as scalability, durability, and ease of fabrication in a variety of materials. Our past work focused on the development of a linear dynamic model for pump design based on maximizing resonance, while little has been done to improve valve shape. Here we present a method for optimizing valve shape using two-dimensional computational fluid dynamics in conjunction with an optimization procedure. A Tesla-type valve was optimized using a set of six independent, non-dimensional geometric design variables. The result was a 25% higher ratio of reverse to forward flow resistance (diodicity) averaged over the Reynolds number range 0<Re⩽2000 compared to calculated values for an empirically designed, commonly used Tesla-type valve shape. The optimized shape was realized with no increase in forward flow resistance. A linear dynamic model, modified to include a number of effects that limit pump performance such as cavitation, was used to design pumps based on the new valve. Prototype plastic pumps were fabricated and tested. Steady-flow tests verified the predicted improvement in diodicity. More importantly, the modest increase in diodicity resulted in measured block-load pressure and no-load flow three times higher compared to an identical pump with non-optimized valves. The large performance increase observed demonstrated the importance of valve shape optimization in the overall design process for fixed-valve micropumps.

Brake hydraulic system resonance analysis

1997 ◽  
Author(s):  
William Chao ◽  
William Chao
Keyword(s):  
Hydraulic System ◽  
Resonance Analysis

Optimization Design for MA5300 Injection Molding Machine’s Clamping Unit’s Hydraulic System

2013 ◽  
Vol 321-324 ◽  
pp. 1770-1774
Author(s):  
Jing Wang ◽  
Zheng Cai Wang ◽  
Li Ying Xue ◽  
Li Zhu Liu
Keyword(s):  
Injection Molding ◽  
Hydraulic System ◽  
Optimization Design ◽  
Response Speed ◽  
Control Circuit ◽  
Hydraulic Control ◽  
Hydraulic Circuit ◽  
Magnetic Exchange ◽  
Oil Source

Focusing on PET perform molding features, working principles of MA5300 Injection Molding Machine’s clamping unit’s hydraulic system has been analyzed in this paper. Based on previous hydraulic system, magnetic exchange valve has been added on the demoulding hydraulic circuit, demolding speed has been fastened; energy accumulator has been added on the control circuit so as to stabilize controlled oil-source, improve time of opening and clamping mould and response speed. In addition, common one-way valve in core oil circuit is replaced with hydraulic control one-way valve, in order to realize pressure maintaining function; hydraulic insurance structure is changed into inner circulation, and two-way cartridge valve is used as security valve, so as to realize faster response, and largely improved equipment security. Through adopting common hydraulic components, under the premise of limited increasing cost, the injection molding cycle for PET perform product has been reduced, and enterprise’s productivity has been improved.

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