Modeling and Analysis on Cushion Characteristics of Fast and High-Flow-Rate Hydraulic Cylinder

Lai, Qiwei; Liang, Liang; Li, Jing; Wu, Shijing; Liu, Jun

doi:10.1155/2016/2639480

Cited by 11 publications

(10 citation statements)

References 20 publications

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“…This approach has been adopted in other studies. [9][10][11][12][13][14][15][16][17][18][19][20][21] These assumptions are commonly used in almost all available hydraulic literatures. [9][10][11][12][13][14][15][16][17][18][19][20][21]…”

Section: Dynamic Modeling Of the Studied Systemmentioning

confidence: 99%

“…The value of the Coulomb friction factor mainly depends on the lubricant annular clearance between the moving piston and its cylinder wall. The preload forces F pr1 and F pr2 , which are caused by the seal squeeze during assembly, are always neglected due to the lubricated contact surface between the pistons and their cylinders walls [10][11][12][13][14][19][20][21] Impact modeling…”

Section: Cylinders Modelingmentioning

confidence: 99%

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Dynamic modeling and simulation of impact in hydraulic cylinders

Gad

2020

Proceedings of the Institution of Mechanical Engineers, Part C:

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In this paper, modeling impact dynamics of a piston and its cylinder body in a hydraulic cylinder is investigated. The studied system consists of two identical hydraulic cylinders controlled by a pressure sequence valve. The impact is assumed as a linear one dimensional and purely translational viscoelastic impact of rigid bodies. Four impact models, the Kelvin-Voigt, the Maxwell, the standard-solid, and the Hunt-Crossley, are considered. Measurements of the transient variations of the cylinders operating pressures and both pistons strokes, at different loading conditions, are conducted. A comprehensive dynamic model of the studied system, considering the four models, is deduced. The Kelvin-Voigt model produced tensile forces by the end of the contact period and it resulted in discontinuities in the contact force during its steady state period. Both results are physically impossible in rigid bodies impacting. In the Maxwell model, large amount of discontinuities appeared in the contact force, which causes the piston to make an infinite number of rebounds during the contact period. In the standard-solid model, the discontinuities in the contact force were found to be much less than those of the Maxwell model. As a result, when the impact occurs, the cylinder pressure gets an overshoot accompanied with large oscillations when the Maxwell model is applied, however, these oscillations do not approximately appear when the standard-solid model is applied. The simulation results showed also that the Hunt-Crossley nonlinear model presented very high penetration depth, which is certainly unrealistic in rigid bodies impacting. The validation of the proposed dynamic models showed that the standard-solid is the most suitable model that may represent the impact in the studied cylinders.

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Section: Dynamic Modeling Of the Studied Systemmentioning

confidence: 99%

Section: Cylinders Modelingmentioning

confidence: 99%

Dynamic modeling and simulation of impact in hydraulic cylinders

Gad

2020

Proceedings of the Institution of Mechanical Engineers, Part C:

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“…Optimal damping performance is based on a proper balance between kinetic energy dissipation of inertial masses and pressure gradient generation. Due to the complex geometries of a throttled outlet orifice along the cushioning stroke, where the flow regimen changes with the operating conditions, area evolution, and flow rates, a single analytical model is considered a significant simplification of the real performance [5][6][7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

“…On the other hand, computational fluid dynamic simulations (CFD) are a suitable tool for the identification of local phenomena like flow, internal pressure, or stress distributions in cushioning devices [9,11]. However, the large time demand of these simulations makes them impractical for dynamical systems modeling.…”

Section: Introductionmentioning

confidence: 99%

Simulation of Hydraulic Cylinder Cushioning

Algar¹,

Freire²,

Castilla³

et al. 2021

Sustainability

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The internal cushioning systems of hydraulic linear actuators avoid mechanical shocks at the end of their stroke. The design where the piston with perimeter grooves regulates the flow by standing in front of the outlet port has been investigated. First, a bond graph dynamic model has been developed, including the flow throughout the internal cushion design, characterized in detail by computational fluid-dynamic simulation. Following this, the radial movement of the piston and the fluid-dynamic coefficients, experimentally validated, are integrated into the dynamic model. The registered radial movement is in coherence with the significant drag force estimated in the CFD simulation, generated by the flow through the grooves, where the laminar flow regime predominates. Ultimately, the model aims to predict the behavior of the cushioning during the movement of the arm of an excavator. The analytical model developed predicts the performance of the cushioning system, in coherence with empirical results. There is an optimal behavior, highly influenced by the mechanical stress conditions of the system, subject to a compromise between an increasing section of the grooves and an optimization of the radial gap.

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“…More recently, Lai et al [17] established three different simulations models (lumped parameter model, integrated simulation model, and Computational Fluid Dynamics (CFD) simulation model) for a Type I cushioning system of a high speed and high flow rate hydraulic actuator. As we could see in other studies, during the hydraulic cylinder cushion, three stages were considered as are local pressure loss, sharp edge throttling, and aperture throttling.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study of 3D Movement in Cushioning of Hydraulic Cylinder

2017

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A double acting cylinder operation has been fully monitored in its key functional parameters, focused on characterization of end-of-stroke cushioning and starting phases. Being the cylinder performance reliant in the piston constructive geometry, the number and location of piston circumferential grooves is a significant parameter affecting the internal cushioning system performance. An eddy current displacement sensor assembled in the piston allows assessment of piston radial displacement inside the cylinder tube, which is directly related with the studied operating phases. Due to such 3D displacements, the piston becomes as an active and self-adjusting element along the functional cycle of the cylinder. Mechanical joints orientation and operating pressure are also relevant parameters affecting piston radial displacement and, thus, the cushioning and starting performance. Computational Fluid Dynamics (CFD) results confirm the observed functional role of the perimeter grooves; the flow and pressure distributions, where develops a significant radial force, are also in accordance with the registered radial displacement.

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Modeling and Analysis on Cushion Characteristics of Fast and High-Flow-Rate Hydraulic Cylinder

Cited by 11 publications

References 20 publications

Dynamic modeling and simulation of impact in hydraulic cylinders

Dynamic modeling and simulation of impact in hydraulic cylinders

Simulation of Hydraulic Cylinder Cushioning

Experimental Study of 3D Movement in Cushioning of Hydraulic Cylinder

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