دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: 1. on a kelly bushing, a cylindrical device that fits inside the bushing, whose exterior shape is matched to the kellys shape so that they mate with the kelly when it is inside the kelly bushing. See kelly bushing, roller assembly. 2. part of a roller bearing. See roller bearing.