Wear Rate Studies of a SS Ball Screw Assembly under No Lubrication Condition

Abstract

Ball screw drives are very popular choices for the purpose of precision motion control applications by the designers. They provide low friction and high efficiency drive systems. In the conventional applications, ball screws are made of high carbon steel materials duly heat treated with proper lubrication. In some of the applications, ball screws are required to be manufactured using corrosion resistant steel. Among them, 17-4-ph, 13-8 Mo materials in heat treated condition are preferred for screw and nut assembly and SS440C or stellite materials are more common for balls. In general, ball-screw drives are used in lubrication condition for achieving desired service life. However, there are some applications where lubrication in the ball screw and nut assembly is not preferred because of inaccessibility for maintenance and degradation of lubricants in the prevailing operation condition. Wear rate data and service life estimates for such difficult operating conditions are neither reported in open literature nor provided by the ball screw manufacturers. Considering this, wear rate data of ball screw assemblies under no lubrication condition has been determined experimentally. Designers may find the experimental results reported herein very much useful in the application of SS ball screws in stringent operating conditions.