Report a Safety Concern
Search

The U.S. Nuclear Regulatory Commission is in the process of rescinding or revising guidance and policies posted on this webpage in accordance with Executive Order 14151 Ending Radical and Wasteful Government DEI Programs and Preferencing, and Executive Order 14168 Defending Women From Gender Ideology Extremism and Restoring Biological Truth to the Federal Government. In the interim, any previously issued diversity, equity, inclusion, or gender-related guidance on this webpage should be considered rescinded that is inconsistent with these Executive Orders.

Home NRC Library Document Collections Events, Reports Associated with Part 21 Reports 1997

Part 21 Report - 1997-063

 
 


ACCESSION #: 9703200381



Limitorque

Corporation

                            February 26, 1997





SUBJECT:       COUNTERFEIT SMB-1 WORM SHAFT GEAR



BACKGROUND



General Public Utilities experienced a clutching problem which was traced

to a loose clutch lug pin in the Worm Shaft gear.  The component was

returned to Limitorque for comment.



LIMITORQUE EVALUATION REVEALED:



     1.   Worm Shaft gear counter bore staking operation to secure motor

          clutch gear cam pin was omitted..  Serious violation.

     2.   Worm Shaft gear lugs were not heat treated.  Serious violation.

     3.   Gear teeth were not shaved.  Profile had significant error.

          Serious violation.

     4.   Variety of other non serious geometric violations.



ENGINEERING CONCLUSIONS



     1.   Worm Shaft gear assembly was not manufactured by Limitorque

          Corporation.

     2.   Worm Shaft gear assembly was inferior in design and manufacture

          referenced to the same Limitorque components and was not

          suitable for the intended application.  The counterfeit

          component would have experienced a short service life

          terminating in failure with associated consequences depending

          upon the criticality of the application.





Ivan E. Wilkinson, P.E., Ph.D

Director of Engineering



Limitorque Corporation  P.O. Box 11318   5114 Woodall Road

Lynchburg, VA 24506-1318   Tel. (804) 528-4400   FAX (804) 845-9736





*** END OF DOCUMENT ***

Page Last Reviewed/Updated Wednesday, March 24, 2021