The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform

J Y Lew - One of the best experts on this subject based on the ideXlab platform.

  • modeling and control of two stage twin Spool servo Valve for energy saving
    American Control Conference, 2005
    Co-Authors: Qinghui Yuan, J Y Lew
    Abstract:

    A control strategy of two stage twin Spool servoValves in the load-sensing mobile applications is presented. The twin Spool Valve differs from the conventional Valve in that it provides the ability to control flow into and out of Valves independently. In this paper, the nonlinear Valve model and a control scheme for a two stage twin Spool servo-Valve are developed featuring energy saving. The multiple sliding surface mode control method is then utilized to accomplish the motion control while regulating back pressure. The simulation verifies that the proposed control scheme for the twin Spool Valve, can offer the more significant energy-saving even with load-sensing pump application than the traditional proportional Valves.

Qinghui Yuan - One of the best experts on this subject based on the ideXlab platform.

  • modeling and control of two stage twin Spool servo Valve for energy saving
    American Control Conference, 2005
    Co-Authors: Qinghui Yuan, J Y Lew
    Abstract:

    A control strategy of two stage twin Spool servoValves in the load-sensing mobile applications is presented. The twin Spool Valve differs from the conventional Valve in that it provides the ability to control flow into and out of Valves independently. In this paper, the nonlinear Valve model and a control scheme for a two stage twin Spool servo-Valve are developed featuring energy saving. The multiple sliding surface mode control method is then utilized to accomplish the motion control while regulating back pressure. The simulation verifies that the proposed control scheme for the twin Spool Valve, can offer the more significant energy-saving even with load-sensing pump application than the traditional proportional Valves.

Zesheng Lu - One of the best experts on this subject based on the ideXlab platform.

  • flow field simulation and a flow model of servo Valve Spool Valve orifice
    Energy Conversion and Management, 2011
    Co-Authors: Guanglin Wang, Zesheng Lu
    Abstract:

    Abstract This paper aims at analyzing the discharge characteristics of servo-Valve Spool Valve under the conditions of laminar and turbulent flow, and establishing a general mathematical model for the orifice flow. The discharge characteristics of Spool Valve orifices are simulated by the CFD method and a formula for discharge coefficient Cd and Reynolds number R is derived. Based on the formula and the submerged orifice flow equation, a general orifice flow mathematical model adapting to meet both turbulent and laminar flow is proposed. Finally, a flapper–nozzle mechanism is designed and machined by the protection part machining method to simulate the Spool Valve orifice. Flow experiments of the flapper–nozzle mechanism and an actual Spool Valve have been carried out, respectively. The flow model is verified through comparing the experimental results with the numerical simulation results.

Guanglin Wang - One of the best experts on this subject based on the ideXlab platform.

  • Design and accuracy analysis of pneumatic gauging for form error of Spool Valve inner hole
    Flow Measurement and Instrumentation, 2012
    Co-Authors: Jun Liu, Guanglin Wang, Xu Dong Pan, Aoyu Chen
    Abstract:

    Abstract The inner hole of a Spool Valve is a slender hole required to have high precision form, and the form error is generally not allowed to exceed 1 μm in servo Valve production. Aiming at ultra-precision measurement for the Spool Valve inner hole in situ, this paper proposes a novel non-contact measurement method based on the differential pressure pneumatic measuring principle and develops a form error pneumatic gauge system for the Spool Valve inner hole. The pneumatic measuring circuit, gauge head and precise driving mechanism have been designed. The factors that influence the accuracy of the pneumatic gauge system have been thoroughly analyzed and tested to evaluate the measuring uncertainty. The system calibration and measurement experiments have been carried out. Results show that the measuring error does not exceed 0.3 μm, which can be further improved by the error separation and compensation technique.

  • flow field simulation and a flow model of servo Valve Spool Valve orifice
    Energy Conversion and Management, 2011
    Co-Authors: Guanglin Wang, Zesheng Lu
    Abstract:

    Abstract This paper aims at analyzing the discharge characteristics of servo-Valve Spool Valve under the conditions of laminar and turbulent flow, and establishing a general mathematical model for the orifice flow. The discharge characteristics of Spool Valve orifices are simulated by the CFD method and a formula for discharge coefficient Cd and Reynolds number R is derived. Based on the formula and the submerged orifice flow equation, a general orifice flow mathematical model adapting to meet both turbulent and laminar flow is proposed. Finally, a flapper–nozzle mechanism is designed and machined by the protection part machining method to simulate the Spool Valve orifice. Flow experiments of the flapper–nozzle mechanism and an actual Spool Valve have been carried out, respectively. The flow model is verified through comparing the experimental results with the numerical simulation results.

  • Pneumatic Measurement Approach for Form Tolerances of Inner Hole in Spool Valve
    Applied Mechanics and Materials, 2010
    Co-Authors: Jun Long Liu, Guanglin Wang
    Abstract:

    Pneumatic measurement and genetic algorithm based approach for form tolerances, including the cylindricity error, circularity error and straightness error of axis, of inner hole in Spool Valve are studied in this paper. A differential pressure type of pneumatic comprehensive measurement approach is put forward, which applies the pneumatic nozzle scanning measurement principle. The minimum zone evaluation and calculation approach for form tolerances based on an improved genetic algorithm is presented considering the characteristics of the measuring point. Finally, the automatic measurement experiment is developed, which can simultaneously measure and evaluate the form tolerances of inner hole in one process.

  • Numerical simulation and experimental research on the characteristic of pneumatic pressure measurement of Spool Valve orifice
    2010 IEEE International Conference on Mechatronics and Automation, 2010
    Co-Authors: Guanglin Wang, Baoliang Cheng, Guoyue Zhang
    Abstract:

    The aim of this paper is to investigate the fluid dynamic behavior of a pneumatic pressure measurement method for the machining quality of servo-Valve Spool Valves. By adopting a CFD technique, the numerical simulations of an ideal metering edge and a metering edge with round corner (fillet) of Spool Valve orifices are carried out respectively. Valve Spool fillet is one of the major influencing factors for metering edge's pressure characteristic and nonlinearity of linearized characteristic curve Y-xv. The nozzle-flapper mechanism and the corresponding fixture are developed to replace ideal Valve Spool and sleeve. Finally, a pneumatic measuring experiment is performed to confirm and explain the simulation results.

  • Simulation Research on Effect of Diametral Clearance of Spool Valve to Valve Orifice Discharge Characteristic
    Key Engineering Materials, 2008
    Co-Authors: Xu Dong Pan, Guanglin Wang, Zhen Hua Liu
    Abstract:

    This paper studies the effect of Spool Valve diametral clearance of electro-hydraulic servo Valve on orifice discharge characteristic. To ensure that the freely sliding between Spool and sleeve, there must be given diametral clearance between Spool and sleeve, which will have an impact on Valve orifice discharge characteristic, this paper first individually sets up a 3D models of clearance from 0 to 5 μm, opening value from 0 to 40 μm, then calculates each model’s discharge on the condition that Valve orifice’s inlet and outlet differential pressure is constant, finally according to the result of the discharge plots the diametral clearance curve of Spool Valve. The quantitative numerical relationship of diametral clearance and Spool Valve characteristic index is given after doing the analysis, Finally, an experimental verification of the simulation results is to be done to prove the simulation results are correct and reliable. The research of this paper provides the basic guidelines for Spool Valve designing and testing.

Jian Deng - One of the best experts on this subject based on the ideXlab platform.

  • Numerical investigation of cavitation flow inside Spool Valve with large pressure drop
    Journal of Physics: Conference Series, 2015
    Co-Authors: Jian Deng, Dingyi Pan, Fangfang Xie, Xueming Shao
    Abstract:

    Spool Valves play an important role in fluid power system. Cavitation phenomena happen frequently inside the Spool Valves, which cause structure damages, noise and lower down hydrodynamic performance. A numerical tools incorporating the cavitation model, are developed to predict the flow structure and cavitation pattern in the Spool Valve. Two major flow states in the Spool Valve chamber, i.e. flow-in and flow-out, are studies. The pressure distributions along the Spool wall are first investigated, and the results agree well with the experimental data. For the flow-in cases, the local pressure at the throttling area drops much deeper than the pressure in flow-out cases. Meanwhile, the bubbles are more stable in flow-in cases than those in flow-out cases, which are ruptured and shed into the downstream.

  • An investigation of the temperature distributions inside a Spool Valve owing to a viscous heating effect
    Proceedings of the Institution of Mechanical Engineers Part C: Journal of Mechanical Engineering Science, 2009
    Co-Authors: Jian Deng, X-m Shao
    Abstract:

    AbstractThe objective of this article is a numerical analysis of the temperature distributions around the notches of a Spool Valve, because of the viscous heating effect caused by high-speed flow of the large-viscosity hydraulic oil. Two Valve Spools fabricated with different shapes of notches are investigated, of which Spool A is an earlier one, being reported to cause a jam fault under specific working conditions. Spool B is an improved one, which has shown no evidence of damage from jamming in applications up to the present. However, except for practical application, no experimental or numerical tests have been carried out to support it. The deformation of the Spool caused by viscous heating is very small, so it is difficult to be observed by conventional experimental methods. In this article, a numerical method is employed to uncover the flow field inside the Valve as well as the temperature distributions on the Valve Spool. The results show important differences between Spool A and Spool B, including...

  • ICIRA (2) - Numerical Study on Viscous Heating of Oil Flow in a Spool Valve
    Intelligent Robotics and Applications, 2008
    Co-Authors: Jian Deng, Xueming Shao
    Abstract:

    The temperature distributions around the notches in Spool Valve were simulated using a finite-volume based CFD code. The temperature increase is due to the viscous heating effect, which is generally significant in high speed oil flow. Two Valve Spools with different types of notches are investigated, of which Spool A is an earlier one, and Spool B is an improved one in order to avoid the heat shock. The results show important difference between Spool A and Spool B, including the local temperature distributions and the maximum temperatures around the notches. As a conclusion, the Spool B is evaluated to be safer from heat shock than Spool A.