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Article
Publication date: 13 August 2018

Zhanling Ji

High pressure and high speed of the axial piston pump can improve its power density, but they also deteriorate the thermal-fluid-structure coupling effect of the friction…

Abstract

Purpose

High pressure and high speed of the axial piston pump can improve its power density, but they also deteriorate the thermal-fluid-structure coupling effect of the friction pairs. This paper aims to reveal the coupling mechanism of the pump, for example, valve plate pair, by carrying out research on multi-physics field coupling.

Design/methodology/approach

Considering the influences of temperature on material properties and thermal fluid on structure, the thermal-fluid elastic mechanics model is established. A complete set of fast and effective thermal-fluid-structure coupling method is presented, by which the numerical analysis is conducted for the valve plate pair.

Findings

According to calculations, it is revealed that the temperature and pressure evolution laws of oil film with time, the pressure distribution law of the fluid, stress and displacement distribution laws of the solid in the valve plate pair. In addition, the forming history of the wedge-shaped oil film and mating clearance change law with rotational speed and outlet pressure in the valve plate pair are presented.

Originality/value

For an axial piston pump operating under high speed, high pressure and wide temperature range, the multi-physics field coupling analysis is an indispensable means and method. This paper provides theoretical evidence for the development of the pump and lays a solid foundation for the research of the same kind of problem.

Details

Industrial Lubrication and Tribology, vol. 70 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 12 August 2019

Guanglin Shi and Haiji Wang

This paper aims to carry out a thermal-hydraulic simulation model for pump and hydraulic system to predict the temperature increasing and pump performance. Based on the…

Abstract

Purpose

This paper aims to carry out a thermal-hydraulic simulation model for pump and hydraulic system to predict the temperature increasing and pump performance. Based on the model, how to alleviate the temperature is introduced. Besides, the optimization of piston is carried out.

Design/methodology/approach

This paper analyzes the heat generation in lubricating interfaces of the pump with energy conversion theory. The heat transfer inside the pump is analyzed with the control volume method. The simulation model is constructed in AMESim because of its operating friendly nature. The experiment is carried out to prove the validity and accuracy of the simulation model.

Findings

Temperature has less effect on the mechanical loss of pump. However, it has a great impact on volumetric efficiency. To reduce the temperature on the piston surface, the size of the piston should be optimized.

Originality/value

This paper fulfills a novel thermal-hydraulic model to evaluate the temperature of the pump. Based on the model, the performance of the pump is determined and optimization is carried out.

Details

Industrial Lubrication and Tribology, vol. 71 no. 6
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 6 March 2009

Fazil Canbulut, Erdem Koç and Cem Sinanoğlu

The purpose of this paper is to experimentally and theoretically investigate slippers, which have an important role on power dissipation in the swash plate axial piston pumps.

Abstract

Purpose

The purpose of this paper is to experimentally and theoretically investigate slippers, which have an important role on power dissipation in the swash plate axial piston pumps.

Design/methodology/approach

The slipper geometry and working conditions affected on the slipper performance have been analyzed experimentally. The model of the slipper system has been established by original neural network (NN) method.

Findings

First, the effects of the slipper geometry with smooth and conical sliding surfaces on the slipper performance were experimentally analyzed. Smooth sliding surface slippers showed a better performance then the conical surface ones. According to the results, the neural predictor would be used as a predictor for possible experimental applications on modeling this type of system.

Originality/value

This paper discusses a new modeling scheme known as artificial NNs an experimental and a NN approach have been employed for analyzing axial piston pumps. The simulation results suggest that the neural predictor would be used as a predictor for possible experimental applications on modeling bearing system.

Details

Industrial Lubrication and Tribology, vol. 61 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 29 August 2019

Bora Lee, Yonghun Yu and Yong-Joo Cho

This paper aims to provide a reliable and efficient numerical piston–cylinder design method and assess the effect of clearance on the piston-cylinder lubrication.

Abstract

Purpose

This paper aims to provide a reliable and efficient numerical piston–cylinder design method and assess the effect of clearance on the piston-cylinder lubrication.

Design/methodology/approach

Numerical analyses of lubrication characteristics were performed for the piston–cylinder interface. The axial piston was numerically modeled, and the film pressure was calculated using the unsteady two-dimensional Reynolds equation. The behavior of the piston was analyzed by calculating the eccentricity satisfying the force and moment balance.

Findings

The secondary motion of the piston included numerically simulated several cycles until the piston behavior converged, and contact with the inner wall of the cylinder and friction region was estimated. Results showed that the piston–cylinder clearance affected the contact force, length of the contact region and leakage flow rate.

Originality/value

This result improves the understanding of the piston–cylinder lubrication and suggests considerations in terms of lubrication in clearance design.

Details

Industrial Lubrication and Tribology, vol. 72 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 9 February 2010

Jian Yang

The purpose of this paper is to investigate, theoretically and experimentally, the sealing performance of the axial piston seal on a larger diameter (100 mm in diameter…

Abstract

Purpose

The purpose of this paper is to investigate, theoretically and experimentally, the sealing performance of the axial piston seal on a larger diameter (100 mm in diameter) axial piston and reveal the sealing mechanism of the axial piston.

Design/methodology/approach

Based on the characteristics of the clearance flow between the seal and the piston, reasonable boundary conditions for Navier‐Stokes' equations are determined and the equations are modified, so that the final equations can describe the real flow state of the clearance flow.

Findings

Through combining the final equations with finite element method, the pressure distributions within the clearance field for the sealing part during the reciprocating motion of the piston and the leakage rate with the pressure are obtained. The deflections of the sealing part which affect sealing performance have been given.

Originality/value

Theoretical and experimental results show the internal relationship between the seal and the piston, also help to develop some newer piston pumps and improve on the seals of present high‐pressure piston pumps.

Details

Industrial Lubrication and Tribology, vol. 62 no. 1
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 October 2004

Fazıl Canbulut, Cem Sinanoğlu, Şahin Yıldırım and Erdem Koç

A neural network is employed to analyze axial piston pump of hydrostatic circular recessed bearing. Owing to complexity of the system, the neural network is used to…

Abstract

A neural network is employed to analyze axial piston pump of hydrostatic circular recessed bearing. Owing to complexity of the system, the neural network is used to predict the bearing parameters of the experimental system. The system mainly consists of cylinder block, piston, slipper, ball‐joint and swash plate. The neural model of the system has three layers, which are input layer with one neuron, hidden layer with ten neurons and output layer with three neurons. It can be outlined from the results for both approaches neural network could be modeled bearing systems in real time applications.

Details

Industrial Lubrication and Tribology, vol. 56 no. 5
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 9 August 2019

Lichen Gu, Rui Xu and Nan Wang

The purpose of this paper is to identify the energy losses factors during the hydro-mechanical conversion process at high pressure via a novel reduced order dynamic model.

Abstract

Purpose

The purpose of this paper is to identify the energy losses factors during the hydro-mechanical conversion process at high pressure via a novel reduced order dynamic model.

Design/methodology/approach

A novel reduced order dynamic model of the axial piston motor was proposed, which provides an explicit insight to the compression flow losses and the Coulomb friction losses. A fully coupled dynamic model of the piston motor was obtained based on the array bond graph method. And then, a reduced order model was obtained by the composition analysis of flow and torque of the axial piston motor. After that, the energy losses estimation model was presented to predict the energy loss of the piston motor under a wide range of working conditions. The model was verified by comparing the experimental and simulation results.

Findings

The simulation result indicates that the flow loss caused by oil compression accounts for 59 per cent of the total flow loss, and the Coulomb friction torque accounts for 40 per cent of the total torque loss under a specific working condition. The compression flow loss and Coulomb friction torque are the major factors that lead to the aggravation of energy loss under extreme working conditions of the piston motor.

Originality/value

At high-pressure condition, the compression flow losses due to fluid compressibility cannot be neglected, and the hydro-mechanical losses in varies friction pairs should involve Coulomb friction losses. Flow and torque loss analytical expression in the model involve the design and control parameters of the piston equipment, which can realize the parameter optimization of the piston equipment for the purpose of energy-saving.

Details

Industrial Lubrication and Tribology, vol. 72 no. 5
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 October 2001

Wang Dong, Li Zhuangyun and Zhu Yuquan

In recent years water hydraulic systems have become of major interest because of the human friendly and environmental safety aspects. The piston pump is one of the most…

Abstract

In recent years water hydraulic systems have become of major interest because of the human friendly and environmental safety aspects. The piston pump is one of the most frequently used hydraulic units in recent engineering techniques. In a water hydraulic piston pump, poor lubrication is more likely to happen than in a oil hydraulic one because of differences in properties between water and oil. There are some key problems, such as corrosive wear and erosion, which are briefly investigated in this paper. Many new materials have been developed, which give longer life expectancies in water without corrosion and erosion. Recently, a new type of seawater hydraulic piston pump with better suction characteristics had been developed at Huazhong University of Science and Technology, China. Much of this research has concentrated on new materials, structure and experiments, which are also specially introduced in this paper.

Details

Industrial Lubrication and Tribology, vol. 53 no. 5
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 February 2003

Yang Huayong, Yang Jian and Zhou Hua

In this paper, experiments were carried out to study the friction and wear performance for the materials of the piston and cylinder in a water hydraulic axial piston pump

Abstract

In this paper, experiments were carried out to study the friction and wear performance for the materials of the piston and cylinder in a water hydraulic axial piston pump. The matching of a 940 stainless steel circle with a F102 engineering plastics block and a 940 stainless steel circle with an Al2O3 ceramic block were also studied. The wearing capacities were calculated by theoretical formulae based on the grinding crack widths. When pure water is used as hydraulic transmission medium, it is better to use ceramic with engineering plastics as matching materials for the piston and cylinder of water hydraulic axial piston pump. The experimental results have provided a theoretical basis for selecting the matching materials of the piston and cylinder.

Details

Industrial Lubrication and Tribology, vol. 55 no. 1
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 May 2009

Fazil Canbulut, Cem Sinanoğlu and Erdem Koç

The purpose of this paper is to investigate experimentally slippers, which have an important role on power dissipation in the swash plate axial piston pumps. Since…

Abstract

Purpose

The purpose of this paper is to investigate experimentally slippers, which have an important role on power dissipation in the swash plate axial piston pumps. Since slippers affect the performance of the system considerably, the effects of surface roughness on lubrication have been studied in slippers with varying hydrostatic bearing areas and surface roughness.

Design/methodology/approach

An experimental set‐up was designed to determine the performance of slippers, which are capable of increasing the efficiency of axial piston pumps, in different conditions.

Findings

The findings suggest that the frictional power loss has been caused by surface roughness, capillary tube diameter, and the size of the hydrostatic bearing area, supply pressure and the relative velocity. In the case of the 0.7 and 9.5 μm surface roughness more power is needed to overcome the friction force between slippers and slipper plates, but less power loss occurs with the slippers with surface roughness of 1.5 μm. The slippers with surface roughness of 1.5 μm are considered, because of the optimum power loss. Moreover, the power loss decreases with increasing capillary tube diameter and supply pressure.

Originality/value

In order to investigate slipper behaviour under different operating conditions, with different capillary tube size and supply pressure an experimental work was carried out for finding exact design parameters of the real time system.

Details

Industrial Lubrication and Tribology, vol. 61 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

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