This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Analysis of Tribofilm Formed by Electric Brush Sliding for Long Life Starter Motor
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 2, 2019 by SAE International in United States
This content contains downloadable datasetsAnnotation ability available
Global exhaust emission regulations are becoming stricter, and vehicles equipped with the idle stop system (ISS) are increasing. Recently, starters for vehicles equipped with ISS are required to improve operation feel when speedily restarted. To satisfy this demand, starters must rotate at higher rotational speeds, and heavier wear in their brushes may cause problems. Tribofilm formed on commutators surface by the brush sliding is an important factor in the brush commutator wear, because tribofilm is said to have a property to increase lubricity and decrease mechanical wear in brushes and commutator, as well as to improve commutation and decrease arc wear. Therefore, for reducing brush commutator wear, it is considered effective to promote film formation by improving materials. However, few researches have been conducted to evaluate the relationship between brush materials and tribofilm formation. In this research, we investigated the influence of the brush materials on tribofilm formation and its mechanism. We conducted brush durability tests changing the amount of WS2 and the kind of graphite, and analyzed the hardness of the tribofilm formed by the tests using Nanoindentation technique. As a result of changing these materials, brush commutator wear was reduced and an increase in film thickness was confirmed. At this time, it was also found that the film hardness significantly increased. It is considered that wear of the tribofilm is reduced due to an increase in film hardness, and sufficient film formation is achieved, leading to a reduction in brush commutator wear.
CitationFukuda, T., "Analysis of Tribofilm Formed by Electric Brush Sliding for Long Life Starter Motor," SAE Technical Paper 2019-01-0181, 2019, https://doi.org/10.4271/2019-01-0181.
Data Sets - Support Documents
|[Unnamed Dataset 1]|
|[Unnamed Dataset 2]|
|[Unnamed Dataset 3]|
- Spry, W.J. and Scherer, P.M., “Copperoxide Film Formation at a Sliding Carbon-Copper Interface,” Wear 4:137-149, 1961.
- Fakih, B. and Dienwiebel, M., “The Structure of Tribolayers at the Commutator and Brush Interface: A Case Study of Failed and Non-Failed DC Motors,” Tribology International 92:21-28, 2015.
- Savage, D.E., Lagally, M.G., and Schrader, M.E., “Electron Spectroscopy Analysis of Contact Surfaces in the Wear of Carbon Brushes Against Copper Commutators,” Appl. Surf. Sci. 7:142-155, 1981.
- Hu, Z.L., Chen, J.T., and Xia, J.T., “Study on surface Film in the Wear of Electrographite Brushes against Copper Commutators for Variable Current and Humidity,” Wear 264:11-17, 2008.
- Yuji, Y. and Sadahiro, K., “Tribology,” Rikougakusya 41-42, 1998.
- Junichi, T., Yoshinori, H., ”Physical Properties of Coating Film ( 2 )~ Surface Properties : Hardness of Coating Film ~,” Study of Coating Film, 152, 2010