Compact, precision duplex bearing mount for high vibration environments

A duplex bearing mount including at least one duplex bearing having an inner race and an outer race, the inner race disposed within the outer race and being rotatable relative to the outer race about an axis, the inner race having substantially no relative movement relative to the outer race in at least one direction along the axis, the inner and outer races each having first and second axial faces which are respectively located at the same axial end of the duplex bearing. The duplex bearing is radially supported by a housing, and a shaft extends through the inner race, the shaft radially and axially supported by the inner race. A first retainer is connected to the housing and engages the first axial surface of a bearing race, the movement of which race in a first direction along the axis being constrained by the first retainer. A second, resilient retainer is connected to the housing or the shaft and is deflected through engagement with the second axial face of a bearing race, the movement of which race in a second direction along the axis, opposite to the first direction, being constrained by the deflected second retainer. The bearing is preloaded by its being clamped between the first and second retainers, and the second retainer forms at least a portion of a spring having the characteristic of a substantially constant force value correlating to a range of various deflection values, whereby the preload of the bearing is substantially unaffected by variations in the deflection of the second retainer.