Loss reduction of a high-speed gear box with the self-vacuuming configuration and the possibility of autonomous lubrication

2014 Fiscal Year Final Research Report

• Project/Area Number: 24560156
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Design engineering/Machine functional elements/Tribology
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: HOUJOH Haruo 東京工業大学, 精密工学研究所, 教授 (40108238)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 歯車 / はすば歯車 / 風損低減 / 真空 / 圧力差損失 / 断熱圧縮 / 潤滑方法

Outline of Final Research Achievements

In high speed gearing such as used in a power generation, windage loss of gears is one of important issue to be eliminated for energy saving of these days. So called self vacuuming, which is realized by arranging a shrouding assembly around the mesh start region of a pair of helical gears as like a gear pump, was investigated as a simple way to decrease the interior pressure. It is confirmed that the vacuuming is successful to reach about 0.002MPa, which means the windage loss potentially reduced by about 80%. However excess loss, named pressure difference loss alternatively becomes marked and exceed the above loss reduction. It is found that the high pressure (atmospheric pressure) at the air vent should be eliminated by using a small vacuum pump with low power consumption. Furthermore, feasibility of lubrication was confirmed by visualizing the oil jet lubrication because the low pressure brings weaker air turbulence to make the jet stable.

Free Research Field

機械要素