THE EFFECT OF PRESSURE AND TIME OF STATIONARY CONTACT UNDER LOAD ON THE STATIC FRICTION COEFFICIENT OF POLYURETHANE ELASTOMERS (EPUR) DURING FRICTION ON STEEL IN VARIOUS LUBRICATING CONDITIONS

摘要

Tribological tests were aimed at determining the value of static friction coefficient μ_0 of EPUR with hardnesses 75, 80, 83, and 93 °ShA, during friction on C45 steel under various lubrication conditions. In the tests, the unit pressure values in the range of p = 0.2-0.8 MPa and the time of stationary contact under load were changed in the range of t = 1-9 min, both in dry friction conditions, lubricating with water, and lubricating with two types of greases - with low and high adhesion to steel. The tests were carried out on a device whose operating principle is based on an inclined plane. The results of the tests showed that both the unit pressure and the stationary contact time have a significant impact on the value of the static friction coefficient in the EPUR-steel pair.