Features of the estimation of the intensity of heat exchange in self-ventilated disk-shoe brakes of vehicles

Abstract

Analysis of the energy load of a cargo vehicle self-ventilated disk-brake system, which significantly affects the operational parameters of its friction pairs is made. Plastic deformation of the disk friction belts can be observed under cyclic loading of the brake friction pairs, and the deformation process is aggravated by the fact that the yield strength of the material drops in their local zones. Due to plastic friction during compression of the disk friction belts heated zones, therefore they bulge, further leading to the formation of microcracks.The research is based on the fact that during the vehicle braking moment, the intensity of heat transfer from the outer and inner, matte and polished surfaces of the self-ventilating braking disk by convection is much lower than the intensity of heat dissipation processes in the right and left body of the half-disks under heat conduction. This is explained by the fact that the rate of heating is ten times higher than the rate of forced air cooling.As a result of the research, the regularities of the thermal conductivity change in the half-disk side surface, the inverse of which is the thermal resistance of the half-disk were revealed. The design and heat transfer processes in the self-ventilated disk-shoe brake of the vehicle are considered. The intensity of heat transfer of a vehicle's self-ventilated brake disk is investigated in relation to speed and with account of heat transfer coefficients from external and internal surfaces of the disk. The influence on the intensity of the heat transfer process on the surface areas through the disk thickness is established