KOIKE Hitonobu

写真a

Affiliation

Engineering educational research section Mechanical and Intelligent Engineering Program 

Title

Assistant Professor

External Link

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Research Areas 【 display / non-display 】

  • Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Machine elements and tribology

  • Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Design engineering

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Papers 【 display / non-display 】

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  • Effect on PEEK/Graphite Film for Raceway Surface of PEEK Hybrid Ball Bearings with Surface Crack

    Koike H., Harajiri T., Haraguchi T., Matsueda T., Mizobe K., Kida K.（ Role： Sole author）

    Springer Proceedings in Materials  2024 

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    To clarify effect on the composite film layer of PEEK and graphite in PEEK hybrid radial alumina ball bearings with surface fatigue cracks, rolling contact fatigue tests were performed by using the PEEK bearing’s inner rings with the surface cracks in the dry and water conditions. When applied load and rotational frequency of the bearing were 98 N and 600–1400 min<sup>−1</sup>, the number of fatigue cycles of the PEEK hybrid bearings reached 1.0E6 cycles. The PEEK composite film containing nano-sized graphite particle covered the surface cracks on the PEEK ring’s raceway after the tests. In addition, friction heat and cyclic compression caused the plastic flow in the composite film layer of PEEK and graphite. Due to effect of the PEEK/graphite film, the fusion of the cracks on the raceway surface of the PEEK inner ring occurred. The accumulation layer of PEEK/graphite film reduced the surface defects such as surface cracks on the raceway of PEEK inner ring, which improved the bearing’s performance.

    DOI： 10.1007/978-981-97-1594-7_2

    Scopus

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MISC 【 display / non-display 】

  • Comparison of Accuracy of Backlash and Fatigue Wear of PEEK-graphite Composite and UHMWPE Bushes in Robot Joint

    Hitonobu Koike, Mizuho Kiba, Kazuya Nishitani, Kenji Kanemasu, Katsuyuki Kida

    FRONTIERS OF MANUFACTURING SCIENCE AND MEASURING TECHNOLOGY V   655 - 662   2015

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    Language：English   Publishing type：Research paper, summary (international conference)  

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Presentations 【 display / non-display 】

  • Wear evaluation of resin composite carbon graphite bearings for canned motor pump in dry environments International conference

    Hitonobu Koike, Kiichiro Arai, Koki Ohira, Shinichiro Ejiri, Masatake Hattori

    The 10th International Conference on Mechanical Structures and Smart Materials  2025.5.17 

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    Event date： 2025.5.17 - 2025.5.19

    Language：English   Presentation type：Oral presentation (general)  

  • Estimation of Wear Damage Areas in a Helical Grooved Plain Bearing using Computational Fluid Dynamics International conference

    T.Nishikawa, S.Ejiri, K. Ohira, H.Koike

    Asian Joint Workshop on Thermophysics and Fluid Science2026 (AJWTF 2026).  (Jeju, Republic of Korea)  2026.9.15  AJWTF 2026 Committee

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    Event date： 2026.9.13 - 2026.9.16

    Language：English   Presentation type：Oral presentation (general)  

    Venue：Jeju, Republic of Korea  

    Bearings are one of the key components determining the reliability of turbomachines. In this study, the focus is on a helical grooved plain bearing used in an industrial canned motor pump. The fluid film pressure distribution in a standard plain bearing without grooves follows the same pattern along the axial direction. However, in the case of bearings with helical grooves, the presence of grooves on the projected area of the bearing causes the fluid film pressure distribution from an asymmetric axial pattern, resulting in uneven load distribution across the bearing. This means that in the case of helical grooves, damage due to wear occurs more frequently in specific
    areas of the bearing. Therefore, if this damage-prone area can be estimated through numerical analysis, it will be possible to identify the areas requiring focused observation during the prototype stage of product development in industry, providing valuable engineering
    insights. Based on this background, the purpose of this study is to demonstrate that it is possible to qualitatively identify the wear damage areas occurring in a helical grooved plain bearing by calculating the liquid film pressure distribution using computational fluid
    dynamics (CFD).
    The methods of this study were numerical analysis using CFD and experiments conducted using a bearing sliding test apparatus. The flow field of an incompressible fluid was solved using the Navier-Stokes equations and the continuity equation by the finite volume method. A fluid domain between the bearing and the shaft is created, and the liquid film pressure distribution within that domain is analyzed. Considering the specifications of industrial canned motor pumps and the bearing sliding test apparatus, the fluid was singlephase room-temperature water. In the experiment, a bearing and a shaft were set up in a water tank filled with room-temperature water, and a sliding test was conducted. The bearing is made of carbon graphite. The shaft is made of metal. The bearing was operated while applying a load to its inner diameter using weights. After operation, the surface of the bearing inner diameter was observed, and the damage state due to wear was analyzed.
    CFD results confirmed that the presence of helical grooves causes the liquid film pressure distribution to be asymmetric in the axial direction. Additionally, the results showed that a peak of negative pressure exists near the center between the helical grooves. When
    comparing the absolute values of the liquid film pressure, the negative pressure values were larger than the positive pressure values.
    Furthermore, experimental results confirmed that bearing wear also exhibits axial asymmetry. These results revealed that areas with greater differences in liquid film pressure along the cylindrical direction indicate more significant wear.
    In conclusion, it is possible to identify areas prone to wear damage in a helical grooved plain bearing by evaluating the fluid film pressure distribution using CFD.

  • ウェット環境下におけるキャンドモータポンプ用滑り軸受の摺動面評価

    西川,金丸, 古池, 江尻, 大平

    日本機械学会 九州支部 九州学生会第57回学生員卒業研究発表講演会  2026.3.9 

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    Event date： 2026.3.9

    Language：Japanese   Presentation type：Oral presentation (general)  

  • ウェット環境下におけるキャンドモータ用滑り軸受の摺動面挙動に関する研究

    西川,金丸, 古池, 江尻, 大平

    ターボ機械協会 第93回島根松江講演会  2025.12.1 

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    Event date： 2025.12.1 - 2025.12.2

    Language：Japanese   Presentation type：Oral presentation (general)  

  • 水中環境下の樹脂含浸カーボングラファイトベアリングのトライボロジー評価

    古池 仁暢 、西川 卓見 、金丸 誠 、江尻 真一郎 、大平 康貴 、服部 雅威

    日本機械学会 2025年度年次大会  2025.9.9 

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    Event date： 2025.9.7 - 2025.9.10

    Language：Japanese   Presentation type：Oral presentation (general)  

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Awards 【 display / non-display 】

  • 優秀講演賞（第57回学生員卒業研究発表講演会）

    2026.3   日本機械学会九州支部   ウェット環境下におけるキャンドモータポンプ用滑り軸受の摺動面 評価

    西川卓見（卒論指導学生）

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    Award type：Award from Japanese society, conference, symposium, etc. 

  • BestPaperAward

    2023.7   CMPSE2023 organizing committee   Effect on PEEK/graphite film for raceway surface of PEEK hybrid ball bearings with surface crack

    H.Koike,T.Haraguchi,T.Harajiri , T.Matsueda , K.Mizobe , K.Kida

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    Award type：Award from international society, conference, symposium, etc. 

  • BestPaperAward

    2019.10   CMPSE2019 organizing committee   Observation of Tribological Wear on PEEK Shaft with Artificial Defect under Radial Rolling Sliding Point Contact

    Hitonobu KOIKE「他」

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    Award type：Award from international society, conference, symposium, etc.  Country：Thailand

  • BestPaperAward

    2019.4   ICAMEM2019 organizing committee   Observation of Tribological Fatigue Fracture on PEEK Shaft with Artificial Defect under One-point Rolling Contact by using 2.5D Layer Method

    Hitonobu KOIKE「他」

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    Award type：Award from international society, conference, symposium, etc.  Country：Hong Kong

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Grant-in-Aid for Scientific Research 【 display / non-display 】

  • 微細加工面の摩擦化学反応によるハイブリッドポリマーベアリング自己潤滑膜の制御

    Grant number：23K03647  2023.04 - 2027.03

    独立行政法人日本学術振興会   科学研究費基金  基盤研究(C)

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    Authorship：Principal investigator 

  • ハイブリッドポリマー軸受の摩擦化学反応による自己修復発現メカニズムの解明

    Grant number：19K04150  2019.04 - 2023.03

    独立行政法人日本学術振興会  科学研究費補助金  基盤研究(C)

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    Authorship：Principal investigator  Grant type：Competitive

  • A study on self-lubrication film with tribo-chemical reaction in hybrid polymer bearing

    Grant number：16K06042  2016.04 - 2019.03

    Grant-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research(C)

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    Authorship：Principal investigator 

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Other research activities 【 display / non-display 】

  • ポンプ開発（軸受の改善等）

    2023.10

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    企業とのポンプ開発評価に関する研究（軸受の改善等）

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Available Technology 【 display / non-display 】

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