Damping Force Modeling and Suppression of Self-Excited Vibration due to Magnetic Fluids Applied in the Torque Motor of a Hydraulic Servovalve

Zhang, Wei; Peng, Jinghui; Li, Songjing

doi:10.3390/en10060749

Cited by 17 publications

(12 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since hydraulic control systems can produce fast linear movement and large forces, they are widely used in many engineering applications, such as robotic manipulators, flight wing control, and many heavy machineries [1], [2]. As the key component of the hydraulic control systems, hydraulic servo valve determines the stability, reliability and output of the hydraulic systems [3], [4]. A two-stage nozzle-flapper servo valve consists of the nozzle-flapper pilot stage and the spool stage.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulations on Flow Characteristics of a Nozzle-Flapper Servo Valve With Diamond Nozzles

Yang

Wen

2019

IEEE Access

View full text Add to dashboard Cite

Nozzle-flapper servo valves are widely used in modern electro-hydraulic control systems of many engineering applications. Flow cavitation in the nozzle-flapper pilot stage could produce noise and cavitation erosion, reducing the performance stability and reliability of the servo valves. In this paper, diamond nozzles are proposed to replace the traditional circular nozzles to reduce the flow cavitation in the nozzle-flapper stage. Numerical simulations using CFD software ANSYS/FLUENT were conducted to explore the flow characteristics of the nozzle-flapper pilot stage. Mass flow rate and image measurements were performed to verify the simulation results. Vapor fraction, lateral velocity, pressure distribution, and flow force are compared in detail between the pilot stage with the traditional nozzles and with the diamond nozzles. It is found that the vapor fraction is greatly reduced under the effect of the diamond nozzles. Finally, to explore the effect of the diamond nozzles on the performance of the nozzle-flapper servo valve, the pressure-flow characteristics and time step response of the load flow rate are examined using the software AMESim. The simulation results show that the pressure-flow characteristics and time step response of the load flow rate almost remain the same. This suggests that the diamond nozzles could suppress the cavitation in the nozzle-flapper servo valve without varying its performance.

show abstract

Section: Introductionmentioning

confidence: 99%

Numerical Simulations on Flow Characteristics of a Nozzle-Flapper Servo Valve With Diamond Nozzles

Yang

Wen

2019

IEEE Access

View full text Add to dashboard Cite

show abstract

“…Cavitation is a complex fluid mechanics phenomenon for nozzles, pumps, injectors, turbines, propellers and a variety of other fluid machinery components. It causes undesired effects such as noise, vibration, power loss and erosion of components in hydraulic valves [3]- [6]. The relationship between inlet pressure fluctuations and unsteady cavitation process conditions inside a water hydraulic poppet valve investigated numerically by Liang et al [7].…”

Section: Introductionmentioning

confidence: 99%

Numerical and Experimental Investigations of Cavitation Phenomena Inside the Pilot Stage of the Deflector Jet Servo-Valve

Saha

Peng

2020

IEEE Access

Self Cite

View full text Add to dashboard Cite

Two-stage electrohydraulic servo-valves play an important role in the most modern hydraulic servo control systems for fight wing controls, manufacturing robots, and many engineering applications. The existence of cavitation inside the pilot stage is one of the root causes of self-excited noise, cavitation erosion, system jam, and frequent failures of electrohydraulic servo-valves. Thus, experimental and numerical investigations of the flow field and cavitation phenomena inside the pilot stage of deflector jet servo-valve under different supply pressures conditions are conducted in this paper. An assembly for experimental verification of the flow visualization process that represents the deflector jet pilot stage is produced and discussed. To test and verify the numerical simulations for cavitation phenomena, the flow field characteristics in the deflector jet pilot stage are investigated by using experimental flow visualization. The cavitation inception inside the pilot stage of the deflector jet servo-valve is experimentally confirmed through flow visualization. More importantly, the attached cloud-like cavitation or bubble shedding is observed along with the jet flow and the significant locations of cavitation inception are also identified for varying supply pressures. The profile of turbulent intensity confirms to conclude that turbulent pressure fluctuations contribute to cavitation. The result also shows that the increment of supply pressure intensifies cavitation and output pressure plays a significant role in reducing the intensity of cavitation inside the pilot stage of deflector jet servo-valve. Finally, the numerical results show good agreement with experimental results. INDEX TERMS Servo-valve, deflector jet servo-valve, turbulent flow, cavitation, numerical simulations.

show abstract

“…Zhang, et al [6] applied novel hybrid-magnetization pole arrays in a torque motor to improve the output torque without increasing its size or mass. In [7], magnetic fluids are filled in the air gap of a torque motor to suppress the vibration and noise. Besides studying the torque motor, scholars have devised some innovative electro-mechanical converters, such as piezoelectric actuator [8], piezoelectric ring benders [9][10][11], and giant magnetostrictive actuators [12,13] to pursue higher dynamic performance.…”

Section: Introductionmentioning

confidence: 99%

Stiffness Model of the Armature Assembly in a Jet Pipe Pressure Servo Valve

Yin

2020

Preprint

View full text Add to dashboard Cite

The armature assembly of the jet pipe pressure servo valve plays an important role in connecting the torque motor and the jet pipe amplifier. A stiffness model of its complex structure is very necessary for analyzing the dynamic/static performance of the jet pipe pressure servo valve. At the present work, the component parts in the armature assembly are simplified into linear elastic beams. The simplified armature assembly is a fourfold statically indeterminate structure under the premise of small deformation. The unknown forces and moments are solved by using the section continuity condition as the additional supplement equation, and the functional relationship between the electromagnetic torque produced from the torque motor and the armature rotation angle /the nozzle displacement is derived based on the Castigliano's Theorem. The finite element model of the armature assembly is also established to calculate the deformation under different loads and different spring tube lengths. The simulated displacements with the finite element method are consistent with the theoretical results. The experimental results of the recovery pressure of the jet pipe valve verified the theoretical model. The proposed stiffness calculation method can be used as a reference for designing and optimizing the armature assembly in the jet pipe pressure servo valve.

show abstract

Damping Force Modeling and Suppression of Self-Excited Vibration due to Magnetic Fluids Applied in the Torque Motor of a Hydraulic Servovalve

Cited by 17 publications

References 26 publications

Numerical Simulations on Flow Characteristics of a Nozzle-Flapper Servo Valve With Diamond Nozzles

Numerical Simulations on Flow Characteristics of a Nozzle-Flapper Servo Valve With Diamond Nozzles

Numerical and Experimental Investigations of Cavitation Phenomena Inside the Pilot Stage of the Deflector Jet Servo-Valve

Stiffness Model of the Armature Assembly in a Jet Pipe Pressure Servo Valve

Contact Info

Product

Resources

About