| 摘要 |
<p>A motor having a rotor shaft extending through a casing, the shaft carrying an armature is disclosed, in which the distance between the assembled front and rear bearings of the motor is affected by accumulated manufacturing tolerance. The distance is therefore indeterminate, being variable in the order of plus or minus .060 inches. The end of the assembled rear bearing is a first reference point. A self-locking unitary retainer ring grips the shaft in a location on the shaft axially outboard of the rear bearing. The retaining ring is referenced to a variable second reference point at the end of the motor casing. The location of the second reference point varies in accordance with the variable accumulated tolerance for a given motor. The retainer ring can be moved along the rotor shaft, and the spacing of the inner surface of the retaining ring from the assembled rear bearing is automatically determined by a spacer of fixed dimension, the spacing corresponding to the difference between the substantially fixed distance from the first reference point at the end of the assembled rear bearing to the second reference point at the end of the casing and the sum of the thickness of the spacer and the thickness of the retainer ring.</p> |
