Stationary roller shaft formed of a material having a low inclusion content and high hardness
AssigneeHoneywell International Inc.
InventorRobert H. Feest
Life of this patent
Estimating the term…
Abstract
An improved stationary roller shaft of a gear assembly for an air turbine starter is provided. The air turbine starter may be used to start a gas turbine engine, such as may be found in aircraft, ships and military vehicles. The stationary roller shaft is formed of a material having a hardness of at least 66 Rockwell C and having a low inclusion content rating, thereby providing improved wear and/or fatigue properties.
Claims28
A stationary roller shaft of a gear assembly for an air turbine starter, the gear assembly comprising a plurality of rolling elements that contact a surface of the stationary roller shaft and are configured to rotate about the stationary roller shaft while the air turbine starter is in operation, the stationary roller shaft comprised of a material having a hardness of at least 66 Rockwell C and having a low inclusion content rating.
An air turbine starter comprising:
- a housing defining an inlet, an outlet, and a flow path between the inlet and the outlet for conveying a flow of pressurized air therebetween;
- a turbine disposed in the flow path and producing turbine shaft power;
- an output shaft for transmitting the shaft power externally of the air turbine starter;
- a gear train coupling the turbine with the output shaft, the gear train having at least one stationary roller shaft formed of a material having a hardness of at least 66 Rockwell C and having a low inclusion content rating.
A gear assembly comprising:
- a stationary roller shaft;
- and
- a plurality of rolling elements configured to rotate about the stationary roller shaft;
- wherein the stationary roller shaft is formed of a material having a hardness of at least 66 Rockwell C and said material is produced by a process including vacuum induction melting, atomization, and hot isostatic compacting.
A kit for installing a stationary roller shaft in a gear assembly, the kit comprising:
- a stationary roller shaft;
- and
- a plurality of rolling elements configured to rotate about the stationary roller shaft;
- wherein the stationary roller shaft is formed of a material having a hardness of at least 66 Rockwell C and a low inclusion content rating.
A stationary roller shaft of a gear assembly formed of a material consisting essentially of, in weight percent, 1.30% carbon, 0.35% manganese, 0.25% silicon, 3.75% chromium, 2.00% vanadium, 6.25% tungsten, 10.50% molybdenum, and 0.03% sulfur.
A stationary roller shaft of a gear assembly, the stationary roller shaft comprised of a material having a hardness of at least 66 Rockwell C, having a low inclusion content rating, and a surface finish of no greater than 8 microinches rms.
Dependencies are inferred from the claim text.