STUDY ON DYNAMIC FRICTION CHARACTERISTICS IN RECIPROCATING FRICTION DRIVE SYSTEM

The dynamic friction characteristics of a reciprocating friction drive system are investigated under conditions of dry contact using 0.45% c arbon steel pair. Three friction modes are found during the operation, i.e. stick-slip, sticking and a transition region. The critical opera ting conditions in classifying these three modes are examined under va rious driver speeds, normal loads and spring constants. The critical v alues of driver speed and normal load increase with increasing spring constant. Generally, in the friction drive system the disappearance of the stick-slip results in smooth rolling. It is also found that the s lope at the first period of slip on the traction force-relative slip v elocity curve would have a transition from negative to positive value when the friction mode of stick-slip changes into sticking. Moreover, results show that the sticking mode gives the best positioning accurac y with the least wear on the contact surfaces. In addition, a transiti on from severe wear to mild wear is found when the friction mode is tr ansferred from stick-slip to sticking only. (C) 1998 Elsevier Science Ltd. All rights reserved.