Effects of Temperature Rise of Grease on Lubricating Performance of Drive Elements under the Extreme Pressure

2021 ◽  
Vol 901 ◽  
pp. 187-192
Author(s):  
Yuh Ping Chang ◽  
Li Ming Chu ◽  
Hsiang Yu Wang ◽  
Chien Te Liu ◽  
Qi Wen Chen
Keyword(s):  
Friction Coefficient ◽  
Temperature Rise ◽  
Electrical Contact ◽  
Load Condition ◽  
Extreme Pressure ◽  
Electrical Contact Resistance ◽  
Heavy Load ◽  
Key Technology ◽  
Effects Of Temperature ◽  
Great Stress

To transfer more power and use it in a heavy load environment, the contact surface between the ball and the track must bear great stress. The temperature always rises due to friction, which is more likely to cause problems of material deformation and fatigue failure. As a result, it will be a key technology to maintain a certain lubricating effect of the transmission components under the environment of heavy load and temperature rise. Through the analysis of friction coefficient and electrical contact resistance, the greases are used to test the lubricating effect of the transmission elements under the heavy load condition. The results will be helpful for the industry to use heavy load greases as a reference.

Experimental study on friction coefficient and temperature rise of heavy-load grease-lubricated spherical plain bearings with surface texture

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jinlong Shen ◽  
Tong Zhang ◽  
Jimin Xu ◽  
Xiaojun LIU ◽  
Kun Liu
Keyword(s):  
Friction Coefficient ◽  
Temperature Rise ◽  
Surface Texture ◽  
Tribological Performance ◽  
Textured Surface ◽  
Textured Surfaces ◽  
Roughness Parameters ◽  
Heavy Load ◽  
Friction Coefficients ◽  
Content Type

Purpose This paper aims to improve the tribological performance of grease-lubricated spherical plain bearings (SPBs) under heavy load, dimple-type textures were prepared by laser on the outer surface of the inner ring. The influence of roughness parameters of a textured surface on reducing friction coefficient and temperature rise was also explored. Design/methodology/approach This study adopts a laser processing method to fabricate dimple-type textures. Three-dimensional roughness parameters were used to characterize the textured surfaces. The friction coefficients of five SPBs with surface texture and one original commercially available SPB without surface texture under different nominal loads were measured on a self-established test rig. The data of temperature rise were obtained by nine embedded thermal couples. Findings The results indicate that SPBs with textures generally exhibit lower friction coefficients than the original SPB without textures. The dimple depth has a significant influence on improving the tribological performance, which coincides with the analysis by surface roughness parameters. A textured surface with negative Ssk and high Vvc has the minimum temperature rise. Originality/value As it is too difficult to arrange sensors into heavy-load SPBs, there are few reports about the temperature characteristics. Through nine embedded thermal couples, the distribution of temperature rise on the inner ring of SPBs was given in this study. The positive effect of surface texture on reducing temperature rise and friction coefficient was verified, which is beneficial for the design of heavy-load SPBs.

The Effect of Triangle-Shaped Surface Textures on the Performance of the Lubricated Point-Contacts

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Wen-zhong Wang ◽  
Zhixiang Huang ◽  
Dian Shen ◽  
Lingjia Kong ◽  
Shanshan Li
Keyword(s):  
Friction Coefficient ◽  
Electrical Contact ◽  
Tribological Performance ◽  
Operating Conditions ◽  
Friction Reduction ◽  
Point Contacts ◽  
Electrical Contact Resistance ◽  
Coverage Ratio ◽  
Lubrication Regimes ◽  
Ratio Size

It has been recognized that purposefully designed surface texturing can contribute to the improvement of tribological performance of elements and friction reduction. However, its optimal parameters may depend on the operating conditions. This paper investigated the effect of a triangle-shaped dimples array on the tribological performance of the lubricated point-contacts under different lubrication regimes, based on the rotational sliding experiment of a patterned steel disk against smooth steel balls. The dimples arrays were produced by laser process and characterized by the 3D profilometer. A series of tests were conducted with different dimple parameters including depth, coverage ratio, size, and direction. Stribecklike curves were obtained to depict the transition of lubrication regimes, and the electrical contact resistance was utilized to qualitatively characterize the lubrication status. The test results showed that the dimples arrays with different sizes, depths and coverage ratios had a distinct effect on the friction behaviors. Compared with the nontextured surfaces, when the dimple depth decreased from 30μm to zero with fixed coverage ratio and size, the friction coefficient firstly decreased, and then increased. The friction coefficient finally approached that of the nontextured surface, during which the lowest value appeared at the dimple depth of approximately 10∼15μm. The coverage ratio of texture showed the similar effect on the friction coefficient. Usually, the coverage ratio of approximately 10% resulted in the lowest friction coefficient. The dimple size and direction also had obvious effects on the friction coefficient. Thus, it can be concluded that there exists a set of optimal values for the dimple depth, coverage ratio, size, and direction to realize the friction reduction.

Electrical Contact Resistance Approach to Tribological Properties of Artificial Joints

2008 ◽  
Vol 594 ◽  
pp. 383-388
Author(s):  
Yuh Ping Chang ◽  
Ruei Hong Wang ◽  
Yu Yang Hung ◽  
Huann Ming Chou ◽  
Jin Chi Wang
Keyword(s):  
Friction Coefficient ◽  
Contact Resistance ◽  
Tio2 Film ◽  
Tribological Properties ◽  
Electrical Contact ◽  
Dynamic Monitoring ◽  
The Novel ◽  
Semiconductor Films ◽  
Electrical Contact Resistance ◽  
Novel Method

The tribo-electrification mechanisms had been successfully applied to dynamic monitor the tribological properties between the metal films by our laboratory members. Moreover, the novel method of using continuous tribo-electrification variations for monitoring showed more sensitive and discriminative than that by the continuous friction coefficient variations as usual. However, the above method is only suitable for the conducted material pairs. This study is based on the above views to further develop another novel method for dynamic monitoring the tribological properties between the semiconductor films in the friction process. The experiment was conducted by the self-developed friction tester and its measure system. The continuous variations of electrical contact resistance and friction coefficient were measured for monitoring the timings of film rupture between the semiconductor films. Moreover, the wear loss was measured by an accuracy balance and the SEM was used to observe the structures of material transfer. Therefore, the wear mechanisms of Ti sliding against Ti with TiO2-film under different normal loads can be investigated. According to the experimental results of this study, the novel method of using electrical contact resistance variations does show great potentialities for dynamic monitoring the tribological properties of the TiO2-film.

scholarly journals A Novel Application on the Drive Elements of Using Electrical Contact Resistance and Friction Coefficient for Evaluating Induction Heat Treatment

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 865
Author(s):  
Yuh-Ping Chang ◽  
Hsiang-Yu Wang ◽  
Huann-Ming Chou
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Electrical Contact ◽  
Extreme Pressure ◽  
Low Friction ◽  
Electrical Contact Resistance ◽  
Treatment Technology ◽  
Induction Heat ◽  
Induction Heat Treatment ◽  
Heat Treatment Mode

The load on drive elements under extreme pressure conditions is significantly larger than that used in machine tools. When operating under a heavy load for a long period, large deformation and severe wear between the ball and the track are more likely to occur. To reduce wear, the most fundamental solution is to improve the surface properties of the material. Moreover, heat treatment is the most effective method to improve the surface properties of materials, thereby achieving wear resistance and low friction. It is necessary to develop a new heat treatment technology for wear resistance in extreme pressure conditions. Therefore, this study conducted experiments using a reciprocating friction tester. The responses of electrical contact resistance and the friction coefficient were measured synchronously to investigate wear resistance and low friction of the alloy steels after the induction heat treatment. Then, the results were compared and verified with low-carbon alloy steel after the traditional carburizing heat treatment. The experimental results show that the application of new induction heat treatment technology can not only improve the performance of drive components, but also save time and energy, and streamline the production process of the drive components. Therefore, the results of these wear analyses confirm that the induction heat treatment mode can replace the traditional carburizing heat treatment mode for drive elements.

Effects of Pure Water on the Tribological Properties of Self-Mated Titanium

2012 ◽  
Vol 591-593 ◽  
pp. 1127-1130
Author(s):  
Yuh Ping Chang ◽  
Jeng Haur Horng ◽  
Huann Ming Chou ◽  
Jin Chi Wang
Keyword(s):  
Friction Coefficient ◽  
Contact Resistance ◽  
Tribological Properties ◽  
Wear Mechanisms ◽  
Pure Water ◽  
Electrical Contact ◽  
Water Lubrication ◽  
Material Transfer ◽  
Electrical Contact Resistance ◽  
Novel Method

The novel method of using continuous variations of the electrical contact resistance and the friction coefficient for monitoring the tribological properties and the wear mechanisms of titanium pairs in air had been applied successfully by the authors. Therefore, this study further investigated the tribological properties and the wear mechanisms of self-mated titanium in pure water. In order to investigate the chemical reactions of titanium sliding against under water lubrication, the continuous variations of electrical contact resistance and friction coefficient were measured. SEM was used to observe the microstructures and of material transfer. The variations of electrical contact resistance were shown to produce clear and strong signals, superior to monitoring continuous friction coefficient variations for the self-mated titanium in pure water. According to the variations of electrical contact resistance, TiO2 was inferred to form at the interfaces of self-mated titanium in pure water. All of the experimental results demonstrated that the water lubrication has great potential for the research.

scholarly journals Comparison Between the Action of Nano-Oxides and Conventional EP Additives in Boundary Lubrication

Lubricants ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 54
Author(s):  
Valdicleide Silva Mello ◽  
Marinalva Ferreira Trajano ◽  
Ana Emilia Diniz Silva Guedes ◽  
Salete Martins Alves
Keyword(s):  
Friction Coefficient ◽  
Boundary Lubrication ◽  
Friction And Wear ◽  
Film Formation ◽  
Environmental Issues ◽  
Protective Film ◽  
Extreme Pressure ◽  
Extreme Pressure Additives ◽  
Environmental Requirements ◽  
Lubrication Conditions

Additives are essential in lubricant development, improving their performance by the formation of a protective film, thus reducing friction and wear. Some such additives are extreme pressure additives. However, due to environmental issues, their use has been questioned because their composition includes sulfur, chlorine, and phosphorus. Nanoparticles have been demonstrated to be a suitable substitute for those additives. This paper aims to make a comparison of the tribological performance of conventional EP additives and oxides nanoparticles (copper and zinc) under boundary lubrication conditions. The additives (nanoparticles, ZDDP, and sulfur) were added to mineral and synthetic oils. The lubricant tribological properties were analyzed in the tribometer HFRR (high frequency reciprocating rig), and during the test, the friction coefficient and percentual of film formation were measured. The wear was analyzed by scanning electron microscopy. The results showed that the conventional EP additives have a good performance owing to their anti-wear and small friction coefficient in both lubricant bases. The oxides nanoparticles, when used as additives, can reduce the friction more effectively than conventional additives, and displayed similar behavior to the extreme pressure additives. Thus, the oxide nanoparticles are more environmentally suitable, and they can replace EP additives adapting the lubricant to current environmental requirements.

Sign in / Sign up

Export Citation Format

Share Document