1989 Fiscal Year Final Research Report Summary
Development of a High-speed Spindle System with a Preload Adjusting Mechanism
| Project/Area Number |
63850036
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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| Allocation Type | Single-year Grants |
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| Research Field |
機械要素
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| Research Institution | Faculty of Science and Technology, KEIO University |
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Principal Investigator |
INASAKI Ichiro Keio University, Dept. of Mechanical Engineering, Professor., 理工学部, 教授 (30051650)
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| Co-Investigator(Kenkyū-buntansha) |
SHIMIZU Tetsu Makino Furaisu Seiki Co., LTD., President., 代表取締役
AOYAMA Tojiro Keio University, Dept. of Mechanical Engineering, Associate Professor., 理工学部, 助教授 (70129302)
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| Project Period (FY) |
1988 – 1989
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| Keywords | Machine Tool / Main Spindle / Ball Bearing / High-Speed Spindle / Preload / Oil-Air Lubrication / Piezo-Electric Element |
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| Research Abstract |
Ball bearings are usually used for spindle systems under preloading. This is an important factor affecting static and dynamic behaviors of machine tools during cutting operations. However, an excessive preload causes a sudden rise of bearing temperature and bearing seizure at high-speed operations. Therefore, the preload on bearings should be adjusted according to the cutting conditions.
In this research, a new spindle system was developed by installing a preload adjusting mechanism using piezo-electric and hydraulic actuators. A new type of oil-air lubrication system was also developed by applying piezoelectric nozzles to the oil-air mixing equipment. The performance of the developed spindle system was evaluated through the impulse-force response test and cutting test. The results obtained through the tests are summarized below. (1) The quality of lubrication was improved by using the piezoelectric oil-air mixing equipment instead of the conventional type. (2) The temperature rise of bearings during high speed operations is effectively suppressed by adjusting a preload at low level, and the occurrence of bearing seizure is also suppressed. (3) The static and the dynamic behaviors of the spindle system are improved by adjusting a preload at high level. (4) By increasing a preload, the occurrence of chatter vibration is effectively suppressed. (5) Higher static and dynamic stiffness are obtained by using the piezo-electric actuators instead of the hydraulic actuators.
The developed new spindle system can be applied not only heavy duty cutting operations but also high-speed cutting operations.
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