US 12,449,029 B2
Bearing retention system
Michael F. Mullen, Cheshire, CT (US); Jimmy Yeung, Woodside, NY (US); and Noah McCreight, Brooklyn, NY (US)
Assigned to Lockheed Martin Corporation, Bethesda, MD (US)
Filed by Lockheed Martin Corporation, Bethesda, MD (US)
Filed on Jun. 28, 2023, as Appl. No. 18/343,230.
Prior Publication US 2025/0003478 A1, Jan. 2, 2025
Int. Cl. F16H 57/021 (2012.01); B64C 27/12 (2006.01); F16C 35/063 (2006.01); F16H 57/02 (2012.01)
CPC F16H 57/021 (2013.01) [B64C 27/12 (2013.01); F16C 35/063 (2013.01); F16C 2326/43 (2013.01); F16H 2057/02043 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A gear box, the gear box comprising:
a housing;
a shaft that is driven by the gear box, the shaft including a recess;
a bearing mounted between the shaft and the housing to support the shaft for rotation with respect to the housing about a rotation axis; and
a ring assembly for axially securing the bearing to the shaft, the ring assembly surrounding the shaft and seated in the recess;
wherein the recess has a retaining surface including:
a conical surface extending at an angle to the rotation axis;
a curved surface that is curved relative to the rotation axis; and
a transition surface extending between the conical surface and the curved surface, the transition surface extending generally parallel to the rotation axis,
wherein the curved surface is larger than the transition surface.
 
10. A bearing retention system for a gear box, the gear box including a housing and a shaft at least partially positioned within the housing of the gear box, the system comprising:
a bearing mounted between the shaft and the housing to support the shaft for rotation relative to the housing about a rotation axis, the bearing adjacent a shoulder formed in the shaft and including,
an inner race surrounding the shaft,
an outer race coupled to the housing, and
a plurality of rollers positioned between the inner race and the outer race to allow rotation of the outer race with respect to the inner race;
a split ring surrounding the shaft, wherein the split ring is selectively engageable within a recess formed in the shaft, wherein the recess and the shoulder are on axially opposite sides of the bearing, the recess having a retaining surface including a conical surface, a transition surface, and a curved surface; and
a locking ring surrounding the split ring and biasing the split ring into the recess;
wherein the bearing is axially secured with respect to the shaft between the shoulder and the recess, and
wherein the transition surface is parallel to the rotation axis and is smaller than the curved surface.
 
15. An aircraft comprising:
a main body extending between a nose and a tail;
a shaft extending between a first end and a second end along an axis, the shaft having a shoulder and a recess including a retaining surface with a conical surface, a transition surface, and a curved surface;
a rotor assembly mounted on the first end of the shaft;
a gear box configured to drive the shaft to rotate the rotor assembly, the gear box including a housing;
a bearing mounted between the shaft and the housing to support the shaft for rotation with respect to the housing about the axis, the bearing resting against the shoulder; and
a ring assembly for axially securing the bearing to the shaft, the ring assembly including,
a split ring at least partially seated within the recess, and
a locking ring surrounding the split ring to bias the split ring into the recess wherein the conical surface extends at an angle to the axis and the transition surface extends parallel to the axis, and
the conical surface is larger than the transition surface.