Investigation of EHL film behavior based on high precision pressure, temperature and film thickness distribution measurement

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K06045
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Design engineering/Machine functional elements/Tribology
• Research Institution: Kyushu Institute of Technology
• Principal Investigator: NISHIKAWA Hiroshi 九州工業大学, 大学院工学研究院, 助教 (40208161)
• Research Collaborator: KANETA Motohiro ; OHNO Nobuyoshi
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 弾性流体潤滑 / 油膜厚さ / 摩擦係数 / グリース

Outline of Final Research Achievements

Mechanical elements such as rolling bearings operate under elastohydrodynamic lubrication (EHL). We improved the measurement method under EHL contact consisting of a ball and a disc and researched its behavior.
The relationship between the entrapped oil film thickness and the approach speed, ball radius, elastic modulus and oil property etc. under impact motion was investigated and a film thickness equation was proposed. The grease formed a thick film at very low speed rolling or vertical motion, and the sliding friction coefficient was largely different depending on the thickener type.

Free Research Field

機械工学、トライボロジー

Academic Significance and Societal Importance of the Research Achievements

垂直運動EHL下の油膜厚さの計算ができることで機械要素の作動状態を予測でき、機械の設計における事前評価が可能になる。グリースが極低速で厚膜を形成すること、極低速垂直運動で増ちょう剤膜の特性を評価することでグリース評価、開発に貢献することができる。潤滑下で作動する機械要素の性能を左右する油膜挙動の把握を行うことで、省エネルギー・省資源につながる機械要素の性能向上・寿命改善が可能になる。