Влияние свойств дискового тормоза с термоизолированными узлами трения на коэффициент трения покоя

Abstract

The article is devoted to analytical determination of dependences of the static idle friction coefficient of a disc brake with thermally insulated friction nodes on influencing factors and experimental confirmation of the final result obtained. The design of the new disc brake provides two friction units, each of which uses materials with different operating temperatures. A characteristic feature of the brake is the thermal insulation of friction units, which allows each pair of friction to provide its own temperature conditions. Carbon and steel are used as friction materials. The characteristics of contact interaction of the working elements of the disc brake are calculated: the dependence of a contour contact area on the radius of curvature of the tops of undulation waves, contour pressures on complex roughness criteria, the integral coefficient of friction of the disc brake with thermally insulated friction nodes on influencing factors. Experimental verification of the obtained results was carried out on a full-scale facility, which allows measuring the forces of static friction under conditions of real forces, pressures and geometry of the contact area. As a result of the study, it was found that the stress strain state of the contact area under conditions of static force interaction corresponds to an elastic unsaturated contact. In this case, when calculating the static friction, the mechanical component of the friction coefficient can be neglected. It has been experimentally confirmed that with the increase in the normal pressing force of the disc brake elements, the coefficient of static friction decreases, which indicates the elastic nature of the interaction of micro-dimensions. Carbon-based friction material is characterized by lower values of the static friction coefficient for all specified values of the clamping force.