Gear Shaft for Accommodating Thermal Expansion and Transmission System Incorporating the Same
AssigneeBell Helicopter Textron Inc.
InventorRyan Thomas Ehinger
Life of this patent
Estimating the term…
Abstract
A gear shaft allows a ceramic bearing to be used in environments where gear steel is desirable for driving a gear. The gear shaft includes a gear region and a bearing region. A bearing can be disposed about the bearing region of the gear shaft. A gear can be disposed about the gear region of the gear shaft. The bearing includes a ceramic material. The gear region of the gear shaft includes gear steel, whereas the bearing region of the gear shaft includes a bearing-region material that has a coefficient of thermal expansion (CTE) that is close to the CTE of the ceramic material.
Claims20
A gear assembly comprising:
- a gear shaft having a gear region and a bearing region;
- a first bearing disposed about the bearing region of the gear shaft;
- and
- a gear disposed about the gear region of the gear shaft,
- wherein the first bearing includes a ceramic material, and
- wherein the bearing region of the gear shaft includes a bearing-region material that has a coefficient of thermal expansion (CTE) that is close to the CTE of the ceramic material.
A gear shaft for rotatably driving a gear while being rotatably supported by a bearing formed of a ceramic material, the gear shaft comprising:
- a gear region for supporting the gear;
- and
- a bearing region for supporting the bearing, the bearing region being fixed to the gear region;
- wherein the bearing region includes a bearing-region material that has a coefficient of thermal expansion (CTE) that is close to the CTE of the ceramic material.
An aircraft comprising:
- a rotor assembly comprising a rotor shaft;
- and
- a transmission for driving the rotor shaft, the transmission comprising a gear assembly, the gear assembly comprising:
- a gear shaft having a gear region and a bearing region;
- a first bearing disposed about the bearing region of the gear shaft;
- and
- a gear disposed about the gear region of the gear shaft,
- wherein the first bearing includes a ceramic material, and
- wherein the bearing region of the gear shaft includes a bearing-region material that has a coefficient of thermal expansion (CTE) that is close to the CTE of the ceramic material.
Dependencies are inferred from the claim text.