국내 최대 기계 및 로봇 연구정보

기술보고서

기술보고서 게시판 내용
타이틀	PERFORMANCE OF SOLID LUBRICATED BALL BEARINGS AT HIGH-TEMPERATURES IN A VACUUM
저자	Katsumi SEKI, Mineo SUZUKI, Makoto NISHIMURA, Masaji HASEGAWA, Minoru MORIYAMA
Keyword	Ball bearings; Silicon nitride; Molybdenum disulphide; Self-lubricating composite; High temperature; Vacuum
URL	http://send.nal.go.jp/send/jpn/dlpdf.php3/naltr01243.pdf?id=NALTR0001243
보고서번호	NAL TR-1243
발행년도	1994.7
출처	NAL (National Aerospace Laboratory of Japan)
ABSTRACT	Ball bearings which can operate at high temperatures in a vacuum will be required with the advances in technology.Among the issues for the operation of ball bearings at high temperatures,solid lubricants and bearing materials are crucial.The aim of this study was to develop ball bearings for use at high temperatures in a vacuum.The tested bearings were 20-mm bore-sized angular contact ball bearings.Three combinations of bearing materials were tested:M-50 bearings,hybrid bearings with M-50 races and Si3N4 balls,and Si3N4 bearings.M-50 bearings were lubricated with a silver film.Hybrid and ceramic bearings were lubricated with a pre-coated sputtered MoS2 film and a self-lubricating hot-pressed composite retainer.Tests were carried out at temperatures up to 500°C and a rotational speed of 600 rpm under an axial load of 50N in a vacuum.Excellent performance at 500°C in a vacuum was obtained for Si3N4 bearings.Frictional torque was low and stable for more than 5×107 revolutions.The bearings after the tewere in very good condition with a small amount of wear.Hybrid bearings also showed very good performance at 350°C in a vacuum.M-50 steel bearings were operated without failure at 350°C in a vacuum,although frictional torque was rather high and unstable.X-ray photoelectron spectroscopy(XPS) analysis and scanning electron microscopy (SEM) observation revealed the existence of a film on the ball surface transferred from the composite retainer for both hybrid and ceramic bearings.