@article{oai:jaxa.repo.nii.ac.jp:00031486,
 author = {曽田, 範宗 and 宮川, 行雄 and SODA, Norimune and MlYAKAWA, Yukio},
 issue = {3_B},
 journal = {東京大学宇宙航空研究所報告},
 month = {Sep},
 note = {玉軸受(#6206)のdn値が(200～250)×10^4に上った場合の軸受温度上昇,摩擦トルク,その他の諸性能,ならびに限界回転数を実験的に明らかにした.dn値が210×10^4までは軸受の摩擦は全体としてほぼ粘性摩擦であり,摩擦トルクは軸受温度における粘度,回転数,油量でほぼ規定しうることを明らかにした.したがってこのdn値までは軸受温度上昇には異常は認められず,ほぼ安全に回転しうる.回転をあげると著しい摩擦の増加を生じ,ついには焼けつきを生ずるが,その限界回転数は油量が多いほど増大する傾向があり,大体85,000 rpm前後,dn値で(250～260)×10^4内外である.また軸受の摩耗,焼けつきはいずれも保持器のすべり摩擦部分にあらわれており,限界回転数を左右するのは保持器の潤滑問題であることも明らかになった., The need is becoming more and more urgent for gas-turbine bearings to be operated safely at very high speeds. Some experiments were conducted to investigate the running performances of a deep-grooved ball bearing (type # 6206) used for gas-turbine operating with dn values ranging between 0.3 × 10^6 and 2.55 × 10^6. Test bearings were rotated by air-turbine of 8 kW at 10 × 10^4 rpm. As for the bearing load, thrust of 50 kg only was given. Turbo-oil of mineral base was used to lubricate the test bearings and the temperature of the inlet oil was varied from 30° to 130℃. Oil was supplied to the bearing by a single nozzle and the flow was varied from 0.22 to 3.0 kg/min. The retainer of the test bearing was made of brass and of outer-race riding type. The test bearings were operated successfully over the range of dn values from 0.3 × 10^6 to 2.1 × 10^6. In this range, the bearing frictional torque was found to be directly proportional to Z^<0.5>-N^<1.3>-Q^<0.25>, where Z is the viscosity of the oil at the bearing outer-race temperature, N the revolutional speed of the shaft, and Q the oil flow per unit time. When the dn value increased above 2.1 × 10^6, bearing failure often occurred, of which the limiting value (the dn value at which the bearing temperature rose rapidly or the bearing frictional torque increased suddenly) depended on oil flow. The more the oil flow, the higher was the limiting dn value. But, however much oil we might supplied to the test bearing, it could not run above dn value of 2.55 × 10^6 (85, 000 rpm). Heavy wear of the retainer occurred at its outside surface, showing the lubrication failure. It must be concluded, therefore, that the retainer locating surface is the most difficult and important lubricating area limiting the high speed rotation of a ball bearing., 資料番号: SA0124377000},
 pages = {344--364},
 title = {<論文>高dn値における玉軸受の性能(V/STOL機用エンジンに関する研究)},
 volume = {1},
 year = {1965}
}