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This study aims to introduce a novel technique which helped in quantifying the wear performance of a roller chain which was lubricated by using the palm oil-based hexagonal boron nitride (hBN) nanoparticles (nano-biolubricant).

The efficiency of the nano-biolubricant was evaluated by using a custom-made roller chain tribometer, at different resistance torque values at a constant speed and running time. Prior to the test, 2 different lubrication conditions were applied. The mass loss and elongation behaviour of a roller chain was selected as a degradation metric for monitoring the amount of the chain wear. The predominant wear mechanism of a roller chain was identified by surface morphological analysis.

Regardless of the lubrication conditions, the wear performance of the roller chain was significantly increased, at increasing resistance torque values. Higher wear was noted when the roller chain was lubricated using a nano-biolubricant, however, the wear curve showed a promising high chain life. The predominant wear mechanism involved is abrasive wear.

Although an increase in the elongation during running is based on the wear between the pins and roller, none of the earlier studies quantified the wear performance of a roller chain under differing lubrication conditions. Hence, for bridging the gap, this study described a new method for measuring the wear performance of the roller chain which was lubricated using the palm oil-based hBN nanoparticles or a nano-biolubricant.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2020-0061/

Looks at a new environmentally‐friendly roller chain. Describes the make‐up and qualities of the three models EFC1, EFC2 and EFC3 and examines some of their common features. The chains do not need lubrication in use and they are relatively small and light. The absence of lubrication means dirt and debris are not attracted to the chain. Concludes that the development of these chains is part of a larger project to develop an environmentally‐friendly transmission system primarily for bicycles but their eventual application could be much wider including use in the food and pharmaceutical industries, office equipment and washing machines.

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.

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.

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.

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.

MANY who realise the implications of White's book on The Organisation Man have probably closed it with the self‐satisfied reflection that ‘it can't happen here.’ That is the anodyne we generally swallow to protect us from disagreeable fears.

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.

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.

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”.

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.

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.

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.

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.

It is found that by selecting an optimal equivalent radius of curvature and prolonging the bush length can improve the lubrication state effectively.

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.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2019-0448.

MAKING its first appearance nine years ago at the Mining Exhibition at Essen, the Cobra conveyor chain lubricator has been used in many European countries for tray transporters, crucible transporters in steelworks, foundries, coke works, and on conveyors and assembly lines for numerous industries. There are two types manufactured, the Cobra 1, which is activated directly by the motion of the transporter, and the Cobra 2, operated by compressed air and controlled by the transporter by means of an actuating arm. The Cobra 1 is used when there is difficulty in employing compressed air or when it is easy to make use of the motion of the conveyor. When compressed air is readily available, however, Cobra 2 is used. It is manufactured by Helios‐Apparate Wetzel & Schlosshauer G.m.b.H., Heidelberg, Germany, and marketed in the U.K. by W. S. Forrest & Co., Almora Hall, Middleton‐St.‐George, Co. Durham.

A heavy duty transfer system has been added to the range of assembly automation elements produced by Bosch of West Germany, more than trebling the workpiece weight that can be handled by the enlarged pallet system.

THE army of young unemployed is a blot on our civilisation. That much would be agreed by all. That nothing very positive is being done about it is also all too evident.