Accession Number : ADA189359

Title :   Improved Oil-Off Survivability of Tapered Roller Bearings.

Descriptive Note : Final rept. 1982-1987,

Corporate Author : TIMKEN CO CANTON OHIO

Personal Author(s) : Kreider, G E ; Lee, P W

PDF Url : ADA189359

Report Date : Oct 1987

Pagination or Media Count : 84

Abstract : This development program was to improve the oil off survivability of a tapered roller bearing when applied to a helicopter transmission, since the tapered bearing has shown a performance advantage in this application. However, the critical roller end rib conjunction is vulnerable to damage in an oil off condition. Through an initial screening, three powdered metal materials were selected to use a rib material for oil off evaluation. These were: M2 steel to a 65% density, CBS 1000M 65% density, CBS 1000M 75% density. The bearing styles tested were both ribbed cone (inner race) and ribbed cup (outer race). Carburized solid CBS 600 was also used as a ribbed material for comparsion of oil off results. The tests were conducted at six speed from 4000 rpm (0.26 million DN) through 37000 rpm (2.4 million DN). The ribbed cup style bearing achieved longer lives than the ribbed cone style. A standard bearing lasted only 10 minutes at 4000 rmp; however, the 30 minute oil off goal was achieved through 11000 rpm using the survivable ribbed cup bearing.

Descriptors :   *ROLLER BEARINGS, CARBURIZING, CONICAL BODIES, HELICOPTERS, POWDER METALS, ROLLERS, TAPER, LUBRICATION, WEAR RESISTANCE, STEEL, POWDER METALS

Subject Categories : Machinery and Tools
      Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE