著者

蟹 拓実 野老山 貴行 梅原 徳次 村島 基之 李 義永 八木下 和宏

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

vol.66, no.7, pp.570-578, 2021-07-15 (Released:2021-07-15)

参考文献数

40

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In general, several mechanical parts are subjected to friction and wear. To prevent wear and high friction coefficient under lubrication, additives can work to reduce friction force, to build up thin film on surfaces which is so-called tribofilm. Recently, Diamond-Like Carbon (DLC) is focused because it has excellent low friction and high wear proof as solid lubricant. However, several researchers already reported that tetrahedral amorphous carbon (ta-C) showed abnormal wear when it rubbed with glycerol mono-oleate (GMO) that is a kind of additive, although it showed very low friction coefficient. To improve tribological properties, new additives were developed that had both phosphate-oxide structure derived from ZnDTP which had high wear resistance and hydroxyl group derived from GMO in one structure. To clarify the effects of the additives, friction tests were performed fixed-roller-on-disk type rotating friction tester. In the friction tests, hydrogenated amorphous carbon (a-C:H) disks, and a-C:H coated rollers were used under boundary lubrication condition at 20-80°C. Friction tests were conducted in Poly-α-olefin (PAO) oil with each GMO and the additives. The results exhibited that a-C:H gave ultra-low friction with the additive. Elemental analysis of the surface showed that tribofilm of phosphorus and oxygen was detected on the a-C:H surface in the additive used condition.

著者

志鷹 拓哉 村島 基之 梅原 徳次 月山 陽介 新田 勇 上坂 裕之 鄧 興瑞

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.854, pp.17-00252-17-00252, 2017 (Released:2017-10-25)

参考文献数

8

被引用文献数

1

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This paper addresses a novel lightweight and low starting torque bearing with looped carbon fiber brush (LCFB). LCFB simulates bristle of living being. Moreover, the static friction coefficient is nearly equal to the kinetic friction coefficient. By applying LCFB to a slide bearings, where a shaft is supported by multiple LCFBs, it is realized low starting torque bearings as well as lightness compared to conventional ball bearings. In this paper, we manufacture prototype LCFB slide bearings. With the bearings, we compare friction torque between LCFB slide bearings, slide bearings and deep groove ball bearings. As results, the ratio of starting torque to regular torque of LCFB slide bearing is from 0.93 to 1.07 which is smaller than that of the slide bearing. When micro-spline shaft is used as a mating material of LCFB slide bearing, the torque reduces because of decrease of real contact area between LCFB and mating materials. In addition, since LCFB utilize elastic deformation of fibers, LCFB slide bearings are not endurable in heavy radial load as high as load rating of ball bearing. Therefore, we define the load capacity of LCFB slide bearing from buckling load of a carbon fiber bundle to avoid overload state. We propose the load capacity as a design guideline of LCFB slide bearings.

著者

大山 慎太郎 梅原 徳次 上坂 裕之 鄧 興瑞 村島 基之 堀江 茂 松山 洋介

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.849, pp.16-00378-16-00378, 2017 (Released:2017-05-25)

参考文献数

13

被引用文献数

1

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This paper describes about the effect of drill surface texturing on height of back burr in titanium alloy drilling process with solid lubricating sheet. Titanium alloy is difficult to conduct drilling because titanium alloy is hard and ductile material. And the workers cannot use plenty of liquid coolant for preventing the productivity decline when the work places are above their heads in production fields. Therefore drills are exchanged frequently even though the cost increases. In this study, we measured the cutting force by a loadcell to know the effect of drill surface texturing and solid lubricating sheet on drilling process of work pieces made of Ti-6Al-4V. As the results, drill with rough textured rake surface showed high burr height in exit of Ti-6Al-4V. On the other hand, drill with rough textured flank surface showed low burr height only if drilling with solid lubricating sheet. Moreover, drill with the specific texturing on flank surface by wire electric discharge machining showed low burr height.

著者

梅原 徳次 後藤 実 月山 陽介 野老山 貴行 吉野 雅彦 川口 雅弘 上坂 裕之 村島 基之

出版者

名古屋大学

雑誌

基盤研究(S)

巻号頁・発行日

2013-05-31

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摩擦誘導ナノ構造層による超低摩擦の安定指針を得るため2つの装置を試作し、超低摩擦発現モデルを提案した。「超低摩擦発現ナノ構造変化層の摩擦時その場計測装置」により、カーボン系硬質膜の無潤滑時の超低摩擦は摩擦で形成するナノ構造変化層の厚さ、硬さ及び表面粗さが重要で、それらのパラメータを用いた「薄膜固体潤滑理論」が超低摩擦モデルとして妥当であることを定量的に明らかにした。また、「超低摩擦摩擦面の表面エネルギーのESEM内その場評価装置」により、摩耗痕の表面エネルギーの低減が摩擦低減に有効であることを定量的に明らかにし、超低摩擦が発現した際はナノ構造層の内部で摩擦する超低摩擦メカニズムを提案した。