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Purpose – This paper aims to present the theoretical and experimental investigation of the temperature of high speed and heavy haul tilting pad journal bearing. Design/methodology/approach – The bearing is 152.15 mm in diameter with three slenderness ratios (L/D) and three clearance ratios. The equations that govern the flow and energy transport are solved by the finite difference method, and the experimental tests are conducted in a test rig of high speed and heavy haul tilting pad journal bearing. The shaft speed ranges from 3,000 to 16,500 r/min (the highest linear-velocity equals 131.4 m/s), and the three static loads are 10, 20 and 30 KN. Findings – The comparisons between numerical results and experimental results show better correlations. It is shown in the theoretical and experimental results that the temperature increases with static load and shaft speed and decreases with clearance ratio and L/D. Originality/value – The theoretical models presented in this paper can be used to predict the temperature of tilting pad journal bearing when the shaft’s linear velocity is up to 130 m/s. [ABSTRACT FROM AUTHOR]

Purpose – The purpose of this paper is to study the effect of particles on the wear of cylinder liner in internal combustion (IC) engine under some typical weather conditions. Design/methodology/approach – Experiments were conducted under some typical dust weather which was simulated by the self-built test-bed with an actual diesel engine. Three-dimensional surface morphology was applied to produce a comprehensive characterization of cylinder liner's wear. Ferrography and oil spectrum analysis were employed for further understanding of the abrasion of the cylinder liner caused by particles. Findings – The presence of particles destroyed the lubricating condition of piston-cylinder liner, speeded up the wear of liner, especially on the thrust side, and aggravated the local wear. Wear curves showed that greater wear volume occurred near bottom dead center on the thrust side under the dust condition. However, on the anti-thrust side, wear volume of top dead center was greater than that of bottom dead center, similar to the wear pattern under the normal condition. Wear rate under dust condition was three to five times of that under normal condition. Research limitations/implications – The paper is restricted to the experimental findings based on single cylinder engine and theoretical researches are needed in the next step. Practical implications – The results help to understand the wear of the cylinder liner from the presence of particles from outside the engine. Originality/value – The paper concentrates on the effect of dust particles on the wear of cylinder liner under some dusty weather conditions simulated by a self-built test-bed, employing an actual IC engine. The results may bring about better understanding of the wear of cylinder liners. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to analyze the temperature field and the heat transfer performance of the counter rotating dual rotor bearings (CRDRB) based on the air phase flow field at different speeds to provide effective support for the lubrication and the thermal design of CRDRB. Design/methodology/approach: In this study, taking H7006C angular contact ball bearing as an example, based on the flow visualization technique and the thermal analysis methods, the effects of outer ring speed on the air phase flow field, the temperature field and the heat transfer in bearing cavity were investigated. Findings: Results indicated that there were more complex turbulent air vortices in CRDRB cavity. Turbulent cyclones in critical contact zone reduced the heat dissipation capacity of air. Compared with single rotor bearing with a static outer ring, the average heat transfer coefficient reduced by 11.78% and the average temperature raised by 3.06 K inside CRDRB cavity. Under the influence of outer ring rotation, the high temperature area in ball-inner raceway contact zone and pocket raised and reduced by 160.13% and 30.48%, respectively. The outer ring rotation had opposite effect on the heat dissipation of raceway contact zone and pocket. Originality/value: The air phase flow field characteristics and the heat transfer performance of CRDRB were revealed and analyzed from the mechanism. An area quantification method was presented as an auxiliary mean of the thermal analysis to evaluate the heat transfer performance of bearing. [ABSTRACT FROM AUTHOR]