Original Date: 06/23/1997
Revision Date: 01/18/2007

Phased Array Tracking to Interception of Target (PATRIOT) Radar Bearing assemblies are received from field units in various states of unserviceablilty depending on environmental conditions, use, etc. The bearing assemblies require remanufacture to ensure stability when aligning the PATRIOT missile radar guidance system.

The bearing assemblies are disassembled and the inner and outer races, balls, and spacers are cleaned. The diameter of the removed balls is measured per specifications. Past practice consisted of replacing the bearing assemblies if the inner and outer bearing race diametral difference exceeded 0.025 inch. The cost to the government was $25 thousand per unit. The new method is to only replace the balls using the following formula to determine the diameter of the new balls (5 times the diameter of the present ball bearing plus the present inside diameter measured using the present balls minus the present outside diameter measured using the present balls minus 0.015 inch) divided by three.

By measuring the balls and the clearance within the races, new balls can be made that ensure the required fit. The cost of materials and labor to replace the balls is approximately $2 thousand. When old bearings were used, alignment times would take up to 24 hours; with the new diameter balls, the realignment procedure takes only three hours.

Replacing the bearing balls in lieu of the bearing assembly has proven cost effective and efficient, and is unique in the measurement procedure for the new balls.

For more information see the Point of Contact for this survey.