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 ***

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