Performance of ball bearings operated at temperatures up to 500{degrees}C in vacuum{copyright}
- National Aerospace Laboratory, Tokyo (Japan); and others
Ball bearing tests were carried out at temperatures up to 500{degrees}C and a rotational speed of 600 rpm under an axial load of 50 N in vacuum. 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 Si{sub 3}N{sub 4} balls, and Si{sub 3}N{sub 4} bearings. M-50 bearings were lubricated with a silver film. Hybrid and ceramic bearings were lubricated with a pre-coated sputtered MoS{sub 2} film and a self-lubricating hot-pressed composite retainer. Excellent performance at 500{degrees}C in vacuum was obtained for Si{sub 3}Ni{sub 4} bearings. Frictional torque was low and stable for more than 5 x 10{sup 7} revolutions. The bearings after the test were in very good condition with a small amount of wear. Hybrid bearings also showed very good performance at 350{degrees}C in vacuum. M-50 steel bearings were feasible for use at 350{degrees} in vacuum, although frictional torque was rather high and unstable. X-ray photoelectron spectroscopic (XPS) analysis and scanning electronic microscopic (SEM) observation revealed existence of a film on the ball surface transferred from the composite retainer for both hybrid and ceramic bearings. 7 refs., 19 figs., 5 figs.
- OSTI ID:
- 229943
- Journal Information:
- Lubrication Engineering, Vol. 51, Issue 9; Other Information: PBD: Sep 1995
- Country of Publication:
- United States
- Language:
- English
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