Engineering topics

Gelotte, Erik

Publications and source records attributed to Gelotte, Erik.

3 records

NASA NTRS2003

Touchdown Ball-Bearing System for Magnetic Bearings

The torque-limited touchdown bearing system (TLTBS) is a backup mechanical-bearing system for a high-speed rotary machine in which the rotor shaft is supported by magnetic bearings in steady-state normal operation. The TLTBS provides ball-bearing support to augment or supplant the magnetic bearings during startup, shutdown, or failure of the magnetic bearings. The TLTBS also provides support in the presence of conditions (in particular, rotational acceleration) that make it difficult or impossible to control the magnetic bearings or in which the magnetic bearings are not strong enough (e.g., when the side load against the rotor exceeds the available lateral magnetic force).

Kingsbury, Edward P.↗

NASA NTRS1994

Design of a high-speed reliable ball bearing

A high-speed, reliable ball bearing has been designed for at least fifteen years of operation in space effectors, MWA's, and RWA's. Advanced bearing concepts have been used in this design, such as: no ball retainer, which eliminates all retainer-related problems; an external lubricazing system that will supply the lubricant at a specified flow rate; and a cartridge assembly that will allow the instrument user to purchase a ready to use bearing assembly, with lubricator. Currently, two assemblies are on life test at 12,000 RPM and have accumulated over 20,000 hours each, with consistent low-torque losses. This paper will describe each of the salient features.

Singer, Herbert B.↗

NASA NTRS1991

Analysis of ITT scan bearing package (bearing package S/N 7-1004)

A geostationary operational environments satellite (GOES) East-West scan-bearing assembly was examined after having completed two and one-half years of operation. The following results were found: (1) lubrication breakdown was found in both bearings; (2) patchy wear-bands running only approximately half-way around the races indicated a load distribution in the ball groups consistent with a very low preload; (3) contact angles of 31.2 deg (S/N 1004) and 28.7 deg (S/N 1004A) were found in bearings whose contact angles are supposed to be 20+/-2 deg; and (4) contamination was present in the bearings.

Gelotte, Erik↗