Dynamics of One-Way Hydraulic Impact System with Two Piston Stop Tools

This paper studies a buffer overflow valve that is attached to a hydraulic rotary motor which could reduce high hydraulic impact when the hydraulic rotary motor starts, brakes or suddenly reverses. A rotary motor buffer overflow valve was modeled and simulated using a computer software, AMESim, and the relation of the buffer overflow valve to the hydraulic impact experienced by the motor was analyzed. The cushioning property of the buffer overflow valve of a rotary motor is verified by using an excavator. It is concluded that having a reasonable design of the buffer overflow valve’s maximum displacement for the buffer set and diameter size for the buffer damping hole, it can reduce the pressure impact experienced by the hydraulic rotary motor and improve its operating performance, which also improves the service life of the system or its hydraulic components.

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Dynamic Stability of an Impact System Connected With Rock Drilling

Journal of Applied Mechanics ◽

10.1115/1.3564765 ◽

1969 ◽

Vol 36 (4) ◽

pp. 743-749 ◽

Cited By ~ 4

Author(s):

C. C. Fu

Keyword(s):

Computer Simulation ◽

Exact Solution ◽

Steady State ◽

Asymptotic Stability ◽

Piecewise Linear ◽

Steady State Solution ◽

External Excitation ◽

Rock Drilling ◽

Impact System ◽

Number Of Cycles

This paper deals with asymptotic stability of an analytically derived, synchronous as well as nonsynchronous, steady-state solution of an impact system which exhibits piecewise linear characteristics connected with rock drilling. The exact solution, which assumes one impact for a given number of cycles of the external excitation, is derived, its asymptotic stability is examined, and ranges of parameters are determined for which asymptotic stability is assured. The theoretically predicted stability or instability is verified by a digital computer simulation.

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Analysis of lubrication and sealing performance on textured piston pair with multi-factor coupling

Industrial Lubrication and Tribology ◽

10.1108/ilt-07-2020-0251 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Song Quan ◽

Yong Guo ◽

Xuedong Liu ◽

Zhewu Chen ◽

Yudi Liu

Keyword(s):

Energy Consumption ◽

Optimization Design ◽

Great Influence ◽

Diameter Ratio ◽

Content Type ◽

Hydraulic Impact ◽

Sealing Performance ◽

Lubrication Performance ◽

Low Energy Consumption ◽

Piston Pair

Purpose This paper aims to study the lubrication and sealing performance on the textured piston pair under the cross action of the shape and structure parameters. This paper further carries out the optimization design of low energy consumption hydraulic impact piston pair. Design/methodology/approach Based on the characteristics of the ring gap seal piston pair, the flow field analysis model of the whole film gap is established for its periodic treatment. The friction power loss of the piston pair is defined as the evaluation index of the lubrication performance and the leakage power loss as the evaluation index of the sealing performance. The orthogonal test design and CFD software were used to analyze the lubrication and sealing performance of the textured piston pair. Findings The cross action of shape and structure factors has a great influence of the lubrication and sealing performance on the textured piston pair. Clearance and shape parameters have great influence on it, while seal length and depth diameter ratio have little influence. The sealing performance of conical textured piston pair is good, while the lubrication performance of square textured piston pair is good. The primary and secondary order of influence of shape and structure on energy consumption on piston pair is B (seal clearance) > C (texture shape) > D (area ratio) > A (seal length) > E (depth diameter ratio). Originality/value Breaking the defect of local optimization design on traditional piston pair structure, then find the matching relationship of structural parameters on textured piston pair. Further improve the lubrication and sealing performance of the piston pair, and provide reference for the global optimization design of the low energy consumption hydraulic impact piston pair.

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Chaotic motion control of a vibro-impact system based on data-driven control method

Journal of Vibration and Control ◽

10.1177/10775463211043320 ◽

2021 ◽

pp. 107754632110433

Author(s):

Xiao-juan Wei ◽

Ning-zhou Li ◽

Wang-cai Ding

Keyword(s):

Motion Control ◽

Data Model ◽

Chaotic Motion ◽

Control Method ◽

Data Driven ◽

Damping Coefficient ◽

Input Output ◽

Output Data ◽

Controlled System ◽

Impact System

For the chaotic motion control of a vibro-impact system with clearance, the parameter feedback chaos control strategy based on the data-driven control method is presented in this article. The pseudo-partial-derivative is estimated on-line by using the input/output data of the controlled system so that the compact form dynamic linearization (CFDL) data model of the controlled system can be established. And then, the chaos controller is designed based on the CFDL data model of the controlled system. And the distance between two adjacent points on the Poincaré section is used as the judgment basis to guide the controller to output a small perturbation to adjust the damping coefficient of the controlled system, so the chaotic motion can be controlled to a periodic motion by dynamically and slightly adjusting the damping coefficient of the controlled system. In this method, the design of the controller is independent of the order of the controlled system and the structure of the mathematical model. Only the input/output data of the controlled system can be used to complete the design of the controller. In the simulation experiment, the effectiveness and feasibility of the proposed control method in this article are verified by simulation results.

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Numerical modeling of the hydraulic impact of riparian vegetation

E3S Web of Conferences ◽

10.1051/e3sconf/20184400194 ◽

2018 ◽

Vol 44 ◽

pp. 00194

Author(s):

Krzysztof Wolski ◽

Tomasz Tymiński ◽

Grzegorz Chrobak

Keyword(s):

Numerical Modeling ◽

Riparian Vegetation ◽

Water Surface ◽

Numerical Models ◽

Three Dimensional ◽

Careful Examination ◽

Impact Structure ◽

Hydraulic Impact ◽

Vegetation Zones ◽

Maximal Shear Stress

This paper presents results of numerical modelling of riverbed segment with riparian vegetation performed with use of CCHE2 software. Vegetation zones are places where dynamic of water flow increases. Therefore, there is a need of careful examination of hydraulic impact structure of such zones. Accurate research is necessary and should be performed with use of physical or numerical models, two or three dimensional. Paper presents distribution of velocity and area of water surface for two variants of vegetation deposition acquired in CCHE2D software and modelled for riverbed with distinctive riparian vegetation. Results point to significant (30–40%) increase of maximal velocities in riverbed with riparian vegetation, while directly near the vegetation there were zones with very low velocities. Local damming occurs before vegetal zone. Maximal shear stress in zones with increased velocity is significantly augmented compared to conditions with no vegetation, which can cause more intensive erosion in those zones

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Response Analysis of van der Pol Vibro-Impact System with Coulomb Friction Under Gaussian White Noise

International Journal of Bifurcation and Chaos ◽

10.1142/s0218127418300434 ◽

2018 ◽

Vol 28 (13) ◽

pp. 1830043 ◽

Cited By ~ 3

Author(s):

Meng Su ◽

Wei Xu ◽

Guidong Yang

Keyword(s):

White Noise ◽

Coulomb Friction ◽

Gaussian White Noise ◽

Original System ◽

Stochastic Averaging ◽

Response Analysis ◽

State Variables ◽

Van Der Pol ◽

Impact System ◽

The Impact

In this paper, the stationary response of a van der Pol vibro-impact system with Coulomb friction excited by Gaussian white noise is studied. The Zhuravlev nonsmooth transformation of the state variables is utilized to transform the original system to a new system without the impact term. Then, the stochastic averaging method is applied to the equivalent system to obtain the stationary probability density functions (pdfs). The accuracy of the analytical results obtained from the proposed procedure is verified by those from the Monte Carlo simulation based on the original system. Effects of different damping coefficients, restitution coefficients, amplitudes of friction and noise intensities on the response are discussed. Additionally, stochastic P-bifurcations are explored.

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