著者

西内 章博 松岡 大起 平山 朋子 松岡 敬 高田 仁志

出版者

一般社団法人 日本機械学会

雑誌

IIP情報・知能・精密機器部門講演会講演論文集

巻号頁・発行日

vol.2017, pp.A-6, 2017

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<p>Surface texturing is attracting much attention especially in the tribology field because for the effect improving the lubrication properties. However, most of studies on surface texturing conduced in the past focused the lubrication properties under a static load, and there are almost no papers on the dynamic characteristics of textured surfaces under a squeezing condition. From these backgrounds, the purpose of this research is to grasp the oil film behaviour on the textured surface under vertical vibration that simulates repeating squeeze motion. The oil film behavior under squeezing motion was observed by means of optical interferometry with two-color light. The experiment showed that the oil film shape in the contact circle under squeezing motion changed due to the existence of microdimples. Particularly, when the glass surface with 500 nm-depth microdimples was used, the oil film became thicker and the contact area became smaller than that when the non-textured surface was used.</p>

著者

角銅 洋実 高田 仁志 平山 朋子

出版者

一般社団法人 日本トライボロジー学会

雑誌

トライボロジスト (ISSN:09151168)

巻号頁・発行日

pp.20-00012, (Released:2021-02-25)

参考文献数

20

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Ball bearings on the main shaft of rocket engine turbopumps which supply cryogenic propellants to the main combustion chamber are critical elements of the entire propulsion system of a rocket. A self-lubricating ball bearing with a retainer made of glass-cloth-polytetrafluoroethylene (PTFE) laminate has been used in turbopumps developed in Japan. In the operation of the turbopump, the bearing heat generation is possible to cause sudden temperature rises of bearing elements which finally result in bearing seizure. Therefore, it is important to predict the accurate bearing heat generation under various operating conditions. In this research, the bearing heat generation operated in cryogenic hydrogen was experimentally investigated under the various operating conditions where the rotational speed and the bearing coolant condition were changed. In addition, the bearing heat generation was compared with that theoretically predicted on a numerical model of mechanical losses. It was finally clarified that the bearing heat generation is influenced dominantly by the friction loss on balls and the drag loss on an inner race.