A drive (1) with a housing (2) and a toothed part (4) which is mounted rotatably relative thereto with a wire race bearing (15), wherein a threaded ring (23) is screwed onto the housing (2) or the toothed part (4), said threaded ring axially fixing the wire race bearing (15) and permitting an adjustment.

An outer ring (26) for a bearing assembly includes an annular backing member (54) having a body, and an annular race member (50). The body has a first portion defining a radial inner surface (98) and a radial outer surface, and a second portion defining an axially-facing base surface (110) and a radially-facing end surface (118). The annular race member has a radial outer face (58) and a radial inner face, and a first axial end face and a second axial end face (70) that both extend between the radial outer face and the radial inner face. The annular backing member is in press-fit engagement with the annular race member such that the radial outer face of the annular race member engages the radial inner surface of the annular backing member and the second axial end face of the annular race member engages the axially-facing base surface of the annular backing member such that the members are unitized.

An electric motor has a stator and a rotor which is arranged on a motor shaft in a rotationally fixed manner. The motor shaft is rotatably mounted about a rotational axis in at least one rolling bearing within a motor housing. The rolling bearing is arranged in a bearing shield in a bearing receiving area, the outer ring of the rolling bearing is pretensioned by a spring disc which sits in the bearing receiving area in a fixed manner to the housing, and the spring disc has an opening and a number of spring elements raised axially towards the outer ring in a disc body surrounding the opening.

A system for use in providing a load on a bearing mounted to a shaft includes a preload apparatus having a first extension and a second extension engageable with an inner race of the bearing and configured to provide a compressive load to the bearing. The first extension has a first projection and the second extension has a second projection. A stop ring is configured to limit a radially inward movement of the first extension and the second extension toward each other to position the first projection and the second projection relative to the bearing.

A system for use in providing a load on a bearing mounted to a shaft includes a preload apparatus having a first extension and a second extension engageable with an inner race of the bearing and configured to provide a compressive load to the bearing. The first extension has a first projection and the second extension has a second projection. A stop ring is configured to limit a radially inward movement of the first extension and the second extension toward each other to position the first projection and the second projection relative to the bearing.

A system for an unmanned aerial vehicle can include an altitude control system, which further includes a compressor assembly, a valve assembly, and an electronics assembly. The compressor assembly may include a driveshaft and a bearing assembly configured to rotate the driveshaft. The driveshaft may be formed from a first material and a compressor housing may be formed from a second material. The first and second materials may have different rates of thermal expansion. A dynamic preloading mechanism, such as a flexible plate, may be provided within the compressor assembly to exert a preloading force on the bearing assembly. Throughout the duration of the flight of the unmanned aerial vehicle, the preloading mechanism can continually compensate for differences in rates of thermal expansion between the first and second materials throughout.

Provided is a power transmission device including a housing and a ball screw device including a nut housed in the housing. The device includes a screw shaft passing through the nut, and balls disposed between the nut and the screw shaft. The device also includes a first bearing and a second bearing that are disposed to be adjacent to each other in a center axis direction parallel with a center axis of the nut between the housing and the nut; and a preload applying member constituted of an elastic body and configured to apply preloads to the first bearing and the second bearing. The first bearing and the second bearing respectively include outer rings that are fitted to the housing and separated from each other in the center axis direction, and the first bearing and the second bearing are disposed to be a face-to-face combination.

A bearing, including: an inner ring defining a first groove; an outer ring including a radially inner surface, the radially inner surface facing an axis of rotation of the bearing and defining a second groove and a third groove; a cage radially disposed between the inner ring and the outer ring; a plurality of balls retained by the cage, and disposed in the first groove, and in the second groove; and a preloaded resilient washer assembly including a rigid washer and a resilient washer including a radially outermost surface disposed in the third groove. The resilient washer urges the rigid washer away from the outer ring in an axial direction parallel to an axis of rotation of the bearing.

A wave spring having an axially resilient spring section including at least one one-layer wave-shaped spring configured to provide a spring force in an axial direction of the wave spring, and a radially resilient spring section configured to provide a spring force in a radial direction. The wave spring may be made from a continuous flat wire that forms both the axially resilient spring section and the radially resilient spring section, the flat wire being rotated 90° at a transition from the axial spring section to the radial spring section.

A packaged bearing unit is disclosed including an outer surface for receiving an aircraft landing gear wheel and an inner surface for receiving an axle. The unit may include first and second spaced-apart sets of tapered roller bearings, held between inner and outer raceways. There may be a bearing setting spacer which can be used when setting and pre-loading the bearings. The bearing unit may be a sealed unit which includes a pre-set amount of lubricant (grease) for lubricating the bearings. One or more sensors may be retained in a void between the sets of bearings. The bearing unit may remain fixed to the axle when the wheel is removed. The bearing unit may be serviced less frequently than the wheels, and may thus have a longer lifetime, possibly comparable with the lifetime of the major components of the landing gear.