The traction behavior of space lubricating oil No. 4116 was measured and analyzed at various oil inlet temperatures below 0 ℃ and various rolling speeds under normal loads by a test rig simulating the operating condi...The traction behavior of space lubricating oil No. 4116 was measured and analyzed at various oil inlet temperatures below 0 ℃ and various rolling speeds under normal loads by a test rig simulating the operating conditions of space bearings. A traction coefficient calculation model was presented. The rheological property and rheological parameters of the lubricant at a low oil inlet temperature were analyzed based on the Tevaarwerk-Johnson model. The results showed that the lubricating oil No. 4116 was sensitive to the rolling speed and had lower sensitivity to the normal load. This lubricating oil is more suitable for applications under high speed when it is used below 0 ℃. It behaves as an elastic-plastic fluid operating below 0 ℃. Both the average limiting shear stress and the average elastic shear modulus have a negative correlation with the rolling speed and oil inlet temperature and have a positive correlation with the normal load.展开更多
Superlubricity is a new area in tribology,in which the slide friction coefficient is about 1/1000 to 1/100 of the general ones.Since the concept of superlubricity was proposed,it has attracted more and more attentions...Superlubricity is a new area in tribology,in which the slide friction coefficient is about 1/1000 to 1/100 of the general ones.Since the concept of superlubricity was proposed,it has attracted more and more attentions from researchers in fields of tribology,physics,chemistry,materials,etc.Many significant progresses have been made during the last two decades in experimental studies on superlubricity.In the present work,the recent advancements in solid superlubricity and liquid superlubricity are reviewed and the lubricating mechanisms of different superlubricity systems are discussed.Finally,the problems on the superlubricity mechanism and the development of superlubricity in the future are addressed.展开更多
In this study, the lubrication performance of the crank pin bearing in a marine two–stroke diesel engine is evaluated to investigate the adhesional failure on the crank pin bearing. A numerical algorithm for the lubr...In this study, the lubrication performance of the crank pin bearing in a marine two–stroke diesel engine is evaluated to investigate the adhesional failure on the crank pin bearing. A numerical algorithm for the lubrication analysis considering motion analysis of the crank pin system is developed. The film pressure and thickness for three clearances and three lubricant temperatures are calculated. The results show that the lubricant temperature has a higher effect on film thickness than clearance. In terms of the film parameter, the operating condition that can result in solid–solid contact is investigated. We also suggest the desirable operating conditions of clearance and lubricant temperature to prevent the solid–solid contact.展开更多
基金supported by the National Science Foundation of China (Nos. 51105131 and 51475143)the Henan Provincial Key Scientific and Technological Project (No. 142102210110)the Tianjin Science and Technology Support Program
文摘The traction behavior of space lubricating oil No. 4116 was measured and analyzed at various oil inlet temperatures below 0 ℃ and various rolling speeds under normal loads by a test rig simulating the operating conditions of space bearings. A traction coefficient calculation model was presented. The rheological property and rheological parameters of the lubricant at a low oil inlet temperature were analyzed based on the Tevaarwerk-Johnson model. The results showed that the lubricating oil No. 4116 was sensitive to the rolling speed and had lower sensitivity to the normal load. This lubricating oil is more suitable for applications under high speed when it is used below 0 ℃. It behaves as an elastic-plastic fluid operating below 0 ℃. Both the average limiting shear stress and the average elastic shear modulus have a negative correlation with the rolling speed and oil inlet temperature and have a positive correlation with the normal load.
基金supported by National Key Basic Research Program of China(Grant No.2013CB934202)Foundation for the Supervisor of Beijing Excellent Doctoral Dissertation(Grant No.20111000305)+1 种基金the National Natural Science Foundation of China(Grant Nos.51021064,51027007)Academic Scholarship for Doctoral Candidates
文摘Superlubricity is a new area in tribology,in which the slide friction coefficient is about 1/1000 to 1/100 of the general ones.Since the concept of superlubricity was proposed,it has attracted more and more attentions from researchers in fields of tribology,physics,chemistry,materials,etc.Many significant progresses have been made during the last two decades in experimental studies on superlubricity.In the present work,the recent advancements in solid superlubricity and liquid superlubricity are reviewed and the lubricating mechanisms of different superlubricity systems are discussed.Finally,the problems on the superlubricity mechanism and the development of superlubricity in the future are addressed.
基金supported by the Pukyong National University Research Abroad Fund in 2015 (C-D-2015- 0500)
文摘In this study, the lubrication performance of the crank pin bearing in a marine two–stroke diesel engine is evaluated to investigate the adhesional failure on the crank pin bearing. A numerical algorithm for the lubrication analysis considering motion analysis of the crank pin system is developed. The film pressure and thickness for three clearances and three lubricant temperatures are calculated. The results show that the lubricant temperature has a higher effect on film thickness than clearance. In terms of the film parameter, the operating condition that can result in solid–solid contact is investigated. We also suggest the desirable operating conditions of clearance and lubricant temperature to prevent the solid–solid contact.
