2004 Fiscal Year Final Research Report Summary
A development of rolling bearings with 10nm level in non-repetitive run-out
Project/Area Number |
15560120
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Design engineering/Machine functional elements/Tribology
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Research Institution | Tokyo University of Science |
Principal Investigator |
NOGUCHI Shoji Tokyo University of Science, Faculty of Science and Engineering, Associate Professor, 理工学部, 助教授 (80349836)
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Project Period (FY) |
2003 – 2004
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Keywords | rolling bearing / NRRO / lubrication fluctuation / rotational accuracy / ball / cage |
Research Abstract |
In this research, the fundamental research was accomplished for a development of rolling bearings with 10 nm level in non-repetitive run-out. The results are summarized as follows ; (1)The non repetitive run-out(NRRO) value of the components of cage rotation is mainly caused by the diameter differences of balls contained in one bearing. But in case of measuring NRRO for a long time, it was often observed that the NRRO of retainer rotation fluctuated suddenly. As for this phenomenon, geometric errors were not regarded as a cause. In this research, we produced the instrument which could let a lubrication state change intentionally and investigated the influence of lubrication fluctuation on the NRRO of retainer rotation. It was cleared that the lubrication fluctuation was the cause of the change of the NRRO of retainer rotation in nm level. (2)The NRRO of rotational frequency of the cage is mainly caused by the diameter differences of balls contained in one bearing. In addition, it was kno
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wn that the unequal orbital intervals of balls could influence the NRRO of rotational frequency of the cage. But there were few quantitative studies about this. In this research, we investigated the influence of the unequal orbital intervals of balls on the NRRO of retainer rotation by pulling out balls intentionally. It was clarified that the NRRO of rotational frequency of the cage became large if the difference between orbital intervals of balls was large. (3)The NRRO value of retainer revolution is caused mainly by the diameter differences of balls mounted in a bearing. Additionally, when more than one ball has diameter difference, the NRRO value of retainer revolution is believed to vary with the location of balls. In this research, we theoretically analyzed the NRRO value of retainer revolution considering the diameter differences and location of balls mounted in a bearing. Consequently, it is clarified that the mean value of the retainer revolution component calculated in all locations of balls decreased with increasing number of balls in a rolling bearing. Less
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Research Products
(6 results)