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Article
Publication date: 1 February 1980

V.A. Belyi, I.V. Kragelskii, V.G. Savkin and A.I. Sviridyonok

EXPERIMENTAL WORK AND RESULTS I. Physical Methods of Polymer Modification PHYSICAL methods can be used to modify the structure of super‐molecules in order to control the…

83

Abstract

EXPERIMENTAL WORK AND RESULTS I. Physical Methods of Polymer Modification PHYSICAL methods can be used to modify the structure of super‐molecules in order to control the mechanical properties of the polymer and revise the frictional properties over a wide range while keeping the chemical structure and molecular weight unchanged.

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Industrial Lubrication and Tribology, vol. 32 no. 2
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 13 April 2020

Hui Li, Heng Liu, Hao Li, Shemiao Qi, Yi Liu and Fengtao Wang

The purpose of this paper is to investigate the effect of the cage-pocket wear on the dynamic behavior of the ball bearing.

226

Abstract

Purpose

The purpose of this paper is to investigate the effect of the cage-pocket wear on the dynamic behavior of the ball bearing.

Design/methodology/approach

Through analyzing the complicated relationship and interactions among the ball bearing elements, the dynamic modeling of the ball bearing was established considering the gravity, drag force from the oil, hydrodynamic effect on the cage and the dynamic simulations with different amounts of the cage-pocket wear loss of the ball bearing (BPWL) were obtained by solving the ball bearing dynamic equations using Runge–Kutta method.

Findings

The results show that the trajectory of the cage’s centroid presents two vibration modes with different amplitudes. In addition, those two different forms of trajectory of different amplitudes emerge alternatively with BPWL increase moreover the diameter of the trajectory decrease significantly with the BPWL increasing, which is consistent with the experimental result and last BPWL has lightly effect on the average skidding ratio of the cage, however, the BPWL would produce significant effects on the fluctuation of the skidding ratio, which can directly reflect the stability of motion to a certain extent.

Originality/value

Practice shows that the bearing failure resulting from the cage accounts for 25 per cent of the total failure of the rolling bearings. However, few discussions about how the wear of the cage-pocket would influence the dynamic characteristics of the cage. This study can provide important ideas for the design of bearing cage-pocket size and the fault identification of the ball bearing to decrease the failure rate caused by the cage.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2019-0535/

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Industrial Lubrication and Tribology, vol. 72 no. 7
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 4 April 2020

Hui Li, Heng Liu, Yi Liu, Shemiao Qi and Fengtao Wang

The purpose of this study is to investigate the dynamic behavior of the ball bearing with cage broken.

263

Abstract

Purpose

The purpose of this study is to investigate the dynamic behavior of the ball bearing with cage broken.

Design/methodology/approach

By analyzing the complicated relationship and interactions among the ball bearing elements, the dynamic modelling of the ball bearing with broken cage was established, and the dynamic simulations were conducted by solving the ball bearing dynamic equations using varying-step Runge–Kutta integration.

Findings

The computational results show that there is considerable distinguishment in the dynamic characteristics between the normal cage and the broken cage of the bears. The broken cage makes the trajectory of the cage erratic, and the vibration amplitude is much bigger than that of the normal cage, which makes the motion of the cage unstable. When one of the cage lintels breaks up, the two adjacent balls will collide with each other; what is worse, this may make the balls crush because of the high amplitude of the collision force. The broken cage makes the cage-race interaction force much larger than that of the normal cage, which could promote the guiding ring and quicken the cage wear-failure.

Originality/value

This study can provide important ideas for the fault identification of the ball bearing with cage broken.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2020-0042/

Details

Industrial Lubrication and Tribology, vol. 72 no. 7
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 June 1967

D.A. ROBINS

FOR A GIVEN piece of machinery involving friction and wear, it is not difficult for the metallurgist to specify, in general terms, the required characteristics of the metals…

19

Abstract

FOR A GIVEN piece of machinery involving friction and wear, it is not difficult for the metallurgist to specify, in general terms, the required characteristics of the metals involved. Difficulties arise, however, in attempting to select or develop materials with the correct combination of properties.

Details

Industrial Lubrication and Tribology, vol. 19 no. 6
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 13 February 2007

Regalla Srinivasa Prakash, U.R.K. Rao and A. Sethuramaiah

To study the nature of scuffing in boundary lubricated sliding contacts with subsurface plastic deformation, as it occurs in plastic deformation processing.

540

Abstract

Purpose

To study the nature of scuffing in boundary lubricated sliding contacts with subsurface plastic deformation, as it occurs in plastic deformation processing.

Design/methodology/approach

Low speed oblique plastic impact testing (LOSOPIT) has been conducted on copper specimen with a hard En31 ball in a test rig that has facility to measure the coefficient of friction. Based on the findings of friction coefficient in these experiments, friction power has been estimated and was found to be in the typical range. Scuffing studies were undertaken both by observation of the slid surface of En31 sphere in a ferrographic microscope with camera facility as well as by calculation of the friction power.

Findings

The boundary lubricant was found to have profound role in safeguarding the surface from severe deformation and micro‐cracks. Scanning electron microscope (SEM) examination of the craters produced by LOSOPIT has given evidence that using the boundary lubricant resulted in smooth transfer of shear stress from the sphere to the specimen surface through the boundary lubricant layer. Owing to this, the asperities have been found flattened in a smooth manner instead of metal at the surface being scuffed. A limited amount of reduction was found in the coefficient of friction due to the use of boundary lubricant from that in the dry testing.

Research limitations/implications

The model used to estimate the friction power is predominantly governed by the friction coefficient itself rather than either the normal load or the sliding speed. Friction coefficient itself may be contributed by various mechanisms all of which may not equally contribute to scuffing. Study is underway to carefully glean out those components of friction that exactly result in scuffing, and to use more effective criteria for scuffing.

Practical implications

The knowledge and data developed in the paper give a clear explanation of conditions under which scuffing can take place in sliding contacts operating under boundary regime. The most important applications are metalforming and metal cutting. It is relevant to mechanical engineering machinery in which intense contact pressures are expected.

Originality/value

This paper fills the gap of lack of scuffing studies in plastic deformation processing. All earlier studies focused on elastic conditions prevailing at the contact. Since, industry has been witnessing a need to tackle the severe problems related to formed product quality and certain defects hitherto unexplained, this paper gives a new direction to explain the defects in products from scuffing point of view. In this paper, it has been shown that friction power can be a good criterion to represent scuffing intensity in boundary lubrication.

Details

Industrial Lubrication and Tribology, vol. 59 no. 1
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 February 2000

Mircea Terheci

Attempts to reveal some of the factors that might cause measurement and evaluation errors in dry sliding. Discusses matters such us “what” and “how” is simulated and “why” and…

339

Abstract

Attempts to reveal some of the factors that might cause measurement and evaluation errors in dry sliding. Discusses matters such us “what” and “how” is simulated and “why” and “what” is really measured and suggests ways to tackle these matters. Presents means of avoiding measurement errors as well as suitable testing procedures. Suggests a strategy of experimental work that encompasses the needs of both pure research and engineering design. It was found that the pin‐on‐disc test largely satisfies the conditions for a good simulation of certain engineering applications while providing a wealth of data for both scientific insight and engineering design.

Details

Industrial Lubrication and Tribology, vol. 52 no. 1
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 December 1966

F.T. Barwell

When machine elements are examined after a period of use it is seldom possible to relate the damage observed with the simple theories of adhesive or abrasive wear. Examples taken…

59

Abstract

When machine elements are examined after a period of use it is seldom possible to relate the damage observed with the simple theories of adhesive or abrasive wear. Examples taken from practice are described and explanations offered based on metallurgical and other changes in the affected surface region. It is concluded that further progress in understanding actual wear situations can only come from a multi‐disciplinary approach.

Details

Industrial Lubrication and Tribology, vol. 18 no. 12
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 26 November 2018

Xiaogang Zhang and Yali Zhang

This study aims to investigate the sliding friction behaviour and mechanism of engineering surfaces.

196

Abstract

Purpose

This study aims to investigate the sliding friction behaviour and mechanism of engineering surfaces.

Design/methodology/approach

A new numerical approach is proposed. This approach derives the macroscale friction coefficient from microscale asperity interactions. By applying this approach, the sliding friction behaviour under different operating conditions were investigated in terms of molecular and mechanical components.

Findings

Numerical results demonstrate an independent relationship between normal load and friction coefficient, which is governed by the saturated plastic ratio. Numerical results also demonstrate that under very small load, an increase in load increases the friction coefficient. In addition, numerical results confirm the existence of optimal surface roughness where the friction coefficient is the lowest. For the surface profiles used in the current calculation, an optimal surface roughness value is obtained as Rq = 0.125 μm.

Originality/value

This new approach characterizes the deterministic relationship between macroscale friction coefficient and microscale asperity molecular/mechanical interactions. Numerical results facilitate the understanding of sliding friction mechanism.

Details

Industrial Lubrication and Tribology, vol. 71 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

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