Rational Design of Vehicle Braking Systems with Reduced Wear of Friction Lining

Abstract

The wear of the friction lining and break drum of a vehicle is uneven. It is, therefore, advisable to reduce wear where it matters most. Knowing the optimal microgeometry of the friction pair surface, this problem can be solved by design-technological methods at the design and manufacturing stages. This paper theoretically solves the problem of finding the friction surface microgeometry, which ensures the uniform wear of a friction lining. A model of a rough friction surface is adopted. To solve the optimization problem posed, the wear-contact problem of the indentation of the friction lining into the brake drum surface is first considered. Temperature functions, contact pressure, stresses, and displacements both in the friction lining and in the brake drum are sought in the form of expansions in a small parameter. For simplicity, the terms containing small parameter degrees that are higher than one are discarded. Each approximation satisfies the system of differential equations of plane thermoelasticity. The solution to the boundary-value problem of the theory of thermal conductivity in each approximation is found by the method of separation of variables. In each approximation, the thermoelastic displacement potential and the power series method are used to solve the thermoelasticity problem. Using the least-squares method, a closed system of algebraic equations is constructed, which allows one to obtain a solution to the problem of optimal design of the drum-lining friction pair, depending on the geometric and mechanical characteristics of both the brake drum and the friction lining. The found microgeometry of the friction surface provides an increase in the wear resistance of the friction lining.

Keywords

• friction pair
• friction lining
• drum
• even wear
• roughness
• optimal microgeometry of the friction surface