A thermal EHL investigation for size effect of finite line contact on bush-pin hinge pairs in industrial chains

2020 ◽  
Vol 72 (5) ◽  
pp. 695-701
Author(s):  
Mingyu Zhang ◽  
Jing Wang ◽  
Peiran Yang ◽  
Zhaohua Shang ◽  
Yi Liu ◽  
...  
Keyword(s):  
Film Thickness ◽  
Peer Review ◽  
Contact Zone ◽  
Line Contact ◽  
Equivalent Radius ◽  
Content Type ◽  
Oil Film ◽  
Finite Line Contact ◽  
Finite Line ◽  
Thermal Ehl

Purpose This paper aims to study the influence of the dimension change of bush-pin on the pressure, oil film thickness, temperature rise and traction coefficient in contact zone by using a thermal elastohydrodynamic lubrication (EHL) model for finite line contact. Concretely, the effects of the equivalent curvature radius of the bush and the pin, and the length of the bush are investigated. Design/methodology/approach In this paper, the contact between the bush and pin is simplified as finite line contact. The lubrication state is studied by numerical simulation using steady-state line contact thermal EHL. A constitutive equation Ree–Eyring fluid is used in the calculations. Findings It is found that by selecting an optimal equivalent radius of curvature and prolonging the bush length can improve the lubrication state effectively. Originality/value Under specific working conditions, there exists an optimal equivalent radius to maximize the minimum oil film thickness in the contact zone. The increase of generatrix length will weaken the stress concentration effect in the rounded corner area at both ends of the bush, which can improve the wear resistance of chain. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2019-0448.

A thermal EHL investigation on plate-pin hinge pairs in silent chains using a narrow finite line contact

2020 ◽  
Vol 72 (10) ◽  
pp. 1139-1145
Author(s):  
Mingyu Zhang ◽  
Jing Wang ◽  
Jinlei Cui ◽  
Peiran Yang
Keyword(s):  
Film Thickness ◽  
Temperature Rise ◽  
Elastohydrodynamic Lubrication ◽  
Radius Of Curvature ◽  
Line Contact ◽  
Equivalent Radius ◽  
Content Type ◽  
Finite Line Contact ◽  
Pressure Peak ◽  
Finite Line

Purpose The purpose of this paper is to numerically study the variations of oil film pressure, thickness and temperature rise in the contact zone of plate-pin pair in silent chains. Design/methodology/approach A steady-state thermal elastohydrodynamic lubrication (EHL) model is built using a Ree–Eyring fluid. The contact between the plate and the pin is simplified as a narrow finite line contact, and the lubrication state is examined by varying the geometry and the plate speed. Findings With increase in the equivalent radius of curvature, the pressure peak and the central film thickness increase. Because the plate is very thin, the temperature rise can be neglected. Even when the influence of the rounded corner region is less, a proper design can beneficially increase the minimum film thickness at both edges of the plate. Under a low entraining speed, strong stress concentration results in close-zero film thickness at both edges of the plate. Originality/value This study reveals the EHL feature of the narrow finite line contact in plate-pin pairs for silent chains and will support the future works considering transient effect, surface features and wear.

Improvement of thermal EHL by selecting bush-pin geometry based on an investigation for industrial chains

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mingyu Zhang ◽  
Jing Wang ◽  
Peiran Yang ◽  
Yi Liu ◽  
Zhaohua Shang ◽  
...  
Keyword(s):  
Peer Review ◽  
Elastohydrodynamic Lubrication ◽  
Radius Of Curvature ◽  
Current Standard ◽  
Equivalent Radius ◽  
Content Type ◽  
Finite Line Contact ◽  
Rounded Corner ◽  
Finite Line ◽  
Pin Geometry

Purpose This study aims to investigate the influence of geometry of bush-pin pair from a perspective of optimal lubrication through a thermal elastohydrodynamic lubrication model for finite line contact. Design/methodology/approach A constitutive equation: Ree-Eyring fluid is used in the calculations. The real chain sizes, i.e. equivalent radius of curvature, bush length, length of the rounded corner area and rounded corner radius, are jointed investigated. Moreover, the effects of the length of the rounded corner area and the radius of rounded corner are investigated. Findings It is found that the current standard of the chain might not consider the importance of lubrication, and the lubrication state can be improved effectively by choosing an optimal radius of rounded corner and the length of the corner area. Originality/value By optimally selecting sizes, the occurrence of high pressure, high temperature rise and near zero film thickness at the ends of bush, especially under heavier load, can be effectively avoided. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2020-0031/

Experimental study on line-contact elastohydrodynamic grease lubrication properties of surface-textured rollers

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fuqin Yang ◽  
Dexing Hu ◽  
Qianhao Xiao ◽  
Shun Zhao
Keyword(s):  
Film Thickness ◽  
Surface Texture ◽  
Inhibitory Effect ◽  
Lubricating Oil ◽  
Line Contact ◽  
Grease Lubrication ◽  
Content Type ◽  
Oil Film ◽  
Crown Width ◽  
Lubrication Properties

Purpose This paper aims to study line-contact elastohydrodynamic grease lubrication properties of surface-textured rollers as well as the effect of different crown widths (dw) on oil film thickness under textured conditions. Design/methodology/approach The laser processing method was used to make the micro-texture on the surface of GCr15 steel rollers; lithium grease was used as the lubricant, and line-contact elastohydrodynamic grease lubrication experiments under pure sliding conditions were performed on light interference elastohydrodynamic-lubricated experimental table. Findings The results show that the line-contact elastohydrodynamic grease lubrication is closely related to the textured crown width of steel rollers. At low speeds and light loads, texturing has an inevitable inhibitory effect on the formation of the lubricating oil film, and the smaller the width of the crown area, the more obvious the inhibitory effect, which is not conducive to the improvement of the lubrication condition. At high speeds and high loads, the textured roller with dw = 1 mm has the largest oil film thickness and shows better lubrication performance. Originality/value At present, there is little research on the surface texture of line-contact friction pairs. This work explores the effect of different textured crown width on the lubricating properties of line-contact elastohydrodynamic grease lubrication by experiment. It provides a new theoretical basis for the subsequent practical application of surface texture technology.

Size effect on thermal elastohydrodynamic lubrication of industrial chain bush-pin hinge pair

2019 ◽  
Vol 71 (9) ◽  
pp. 1080-1085 ◽  
Author(s):  
Mingyu Zhang ◽  
Jing Wang ◽  
Yi Liu ◽  
Longjie Dai ◽  
Zhaohua Shang
Keyword(s):  
Friction Coefficient ◽  
Film Thickness ◽  
Temperature Rise ◽  
Elastohydrodynamic Lubrication ◽  
Curvature Radius ◽  
Line Contact ◽  
Content Type ◽  
Oil Film ◽  
Industrial Chain ◽  
Infinite Line

Purpose The purpose of this paper is to use elastohydrodynamic lubrication (EHL) theory to study the variation of the equivalent curvature radius “R” on the change of oil film thickness, pressure, temperature rise and friction coefficient in the contact zone between bush-pin in industrial chain drive. Design/methodology/approach In this paper, the contact between bush and pin is simplified as infinitely long line contact. The lubrication state is studied by numerical simulation using steady-state line contact thermal EHL. The two constitutive equations, namely, Newton fluid and Ree–Eyring fluid are used in the calculations. Findings It is found that with the increase of equivalent curvature radius, the thickness of oil film decreases and the temperature rise increases. Under the same condition, the friction coefficient of Newton fluid is higher than that of Ree–Eyring fluid. When the load increases, the oil film thickness decreases, the temperature rise increases and the friction coefficient decreases; and the film thickness increases with the increase of the entraining speed under the condition “R < 1,000 mm”. Research limitations/implications The infinite line contact assumption is only an approximation. For example, the distances between the two inner plates are 5.72 mm, by considering the two parts assembled into the inner plates, the total length of the bush is less than 6 mm. The diameter of the pin and the bore diameter of the bush are 3.28 and 3.33 mm. However, the infinite line contact is also helpful in understanding the general variation of oil film characteristics and provides a reference for the future study of finite line contact of chain problems. Originality/value The change of the equivalent radius R on the variation of the oil film in the contact of the bush and the pin in industrial chain drive was investigated. The size effect influences the lubrication characteristic greatly in the bush-pin pair.

An adjustable oil film thickness test rig for detecting lubrication characteristics of slipper/swash-pair in piston pumps

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Haiji Wang ◽  
Guanglin Shi
Keyword(s):  
Film Thickness ◽  
Peer Review ◽  
Relative Error ◽  
Mathematical Analysis ◽  
Test Rig ◽  
Content Type ◽  
Oil Film ◽  
Displacement Sensors ◽  
Measuring Machine ◽  
Lubrication Characteristics

Purpose The purpose of this paper is to propose an adjustable oil film thickness test rig for detecting lubrication characteristics of the slipper. The mathematical analysis of lubrication is introduced. Based on the results from the test rig, the results comparison from test rig and mathematical analysis is carried out. Design/methodology/approach This paper introduces a mechanism which can adjust the oil film thickness between the slipper and swash-plate. Feasibility is ensured, and the accuracy of test rig is guaranteed by the three-coordinate measuring machine. Three displacement sensors show the oil film thickness and its shape. The reacting force and torque resulting from oil film can be achieved by three S-type force sensors and a torque sensor, respectively. Findings The relative error of the reacting force is small. The relative error reduces and is acceptable when the deformation of retainer is taken into account. The thickness and tilt angle of oil film have less effect on the reacting force. However, they are significantly impact on torque. Originality/value The test rig proposed in this paper is able to adjust the oil film thickness, which is used to detecting the lubrication characteristics in pump design. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2020-0166/

Experimental Investigation for Finite Line Contact Edge Effect of Elastohydrodynamic Lubrication

2012 ◽  
Vol 538-541 ◽  
pp. 1945-1951 ◽  
Author(s):  
Yu Xue ◽  
Tong Shu Hua ◽  
Hao Yang Sun
Keyword(s):  
Experimental Investigation ◽  
Film Thickness ◽  
Contact Area ◽  
Elastohydrodynamic Lubrication ◽  
Line Contact ◽  
Heavy Load ◽  
Entrainment Velocity ◽  
Finite Line Contact ◽  
Finite Line ◽  
Lubricant Viscosity

To reveal the principle of the close effect about the EHL finite roller, contraposing the log-convex roller, the finite line contact EHL film shape and thickness were observed through self-made heavy-load optical EHL experimental device. Experiments were carried out under several different pressure and viscosity, and three groups of interference pictures were obtained under three different entrainment velocities. As the load increased, both the length and width of the roller contact area added, and the width of the contact zone in the end was larger than that in the centre, the close effect was more obvious; when the entrainment velocity and lubricant viscosity increased, the film thickness in the central roller became thicker while the increase in the roller end was little, the high film thickness difference enhanced the close effect. The entrainment velocity, load and lubricant viscosity all have great effect on the EHL characteristics of the finite roller.

Influence of Different Viscosity Lubricant to Finite Line Contacts on Elastohydrodynamic Lubrication (EHL) under Oscillating

2012 ◽  
Vol 538-541 ◽  
pp. 1939-1944
Author(s):  
Yan Fei Wang ◽  
Tong Shu Hua ◽  
Hao Yang Sun
Keyword(s):  
Film Thickness ◽  
Elastohydrodynamic Lubrication ◽  
Oil Film ◽  
Entrainment Velocity ◽  
Finite Line Contact ◽  
Line Contacts ◽  
Finite Line ◽  
Contact Roller ◽  
Two Parameters ◽  
Experimental Rig

To make further researches into the elastohydrodynamic lubrication properties of a finite line contact roller, oscillating experiments were carried out on made overload experimental rig for oil film measurement using optical interference technique. Film thickness and shape were measured in two kinds of viscosity polyisobutylene. This study indicates that both lubricant viscosity and roller entrainment velocity play an important role on EHL of finite line contacts. On motion, the more increase in viscosity or speed, the thicker the oil film thickness, simultaneity edge effect is distinctly intensified and film thickness increases less on roller end, difference of the film thickness is increased between roller end and the central. Above two parameters are significant for logarithmic profile roller in crowning design.

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