Patent ID: 9583996
Date: 2017-02-28
CPC Classifications: H01H,H02K,Y10T

Claim:
1. An overspeed protection system for a drive motor comprising: a shaft coupled to the drive motor for rotation; a centrifugal actuator having a cylindrical body configured to be axially mountable at a predetermined location on the shaft for rotation with the shaft, the centrifugal actuator configured to control the drive motor in response to exceeding a rotational speed threshold; an overspeed guard having a cylindrical collar configured to be axially mountable on the shaft for rotation with the shaft, said overspeed guard configured to substantially surround said centrifugal actuator in the radial direction to contain the centrifugal actuator in an overspeed condition; and a location and retention component for positively locating at least the overspeed guard at an optimum positional relationship relative to the centrifugal actuator to contain the centrifugal actuator in an overspeed condition, wherein the cylindrical body of the centrifugal actuator includes a body end face and said cylindrical collar of the overspeed guard includes a collar end face facing said body end face of the cylindrical body of the centrifugal actuator, the cylindrical body and the cylindrical collar are mounted on the shaft with a gap between said body end face of the cylindrical body and said collar end face of the cylindrical collar that is less than about 0.05 inches.