Analysis On Heat Frictional Characteristic Of The Multi-disc Wet Brake

With the improving of domestic road traffic capacity, the running speed ofEngineering-truck is significantly increasing, leading to the increasing of brakingefficiency. As one of a critical component to evaluate the safety performance of vehicle,the braking performance of brakes has a direct effect on the security of vehicletransportation, which is close related with its friction behavior.Multi-discs wet brakeshas a remarkable advantages characterized by larger braking torque, higher brakingefficiency and better sealing performance. So it has a wide application inEngineering-truck.The friction properties of wet-brakes have direct relationship withheat transfer, friction coefficient, thermal-mechanical coupling and braking shaking. Noaccurate theoretical model and motion mechanism was found on massive literatures. Aanalysis model about heat transfer, axial symmetry heat-friction coefficient, axialsymmetry heat-heat wear, thermal-mechanical coupling, and braking shaking of thewet-brakes was established, which can better fit into the actual working situation.Thefriction properties of multi-discs wet brake were examined by the way of FEA analysis.The contents investigated in this article were as follows:A、A plane heat transfer mathematical model of friction pair was established inorder to analyzing the effects of multi-discs wet brakes structure on friction properties.Temperature changing characteristics of various amounts of friction linings and frictionlinings temperature according to actual structure parameters in axial direction wereanalyzed, which provide theory for the study of braking structure.B、In order to analyze the effects of fatigue wear of braking friction and heatfriction coefficient on friction properties of wet brakes, axial symmetry gradientchanging of friction heat flow and convection heat transfer mathematical model andheat wear and related parameter response character function model were established.The corresponding distribution of transient temperature, braking time, frictioncoefficient, heat wear amount and heat wear rate was analyzed. The friction coefficient,heat wear amount of the friction pair material can be changed by controllingtemperature and time. Then the friction stability of brake in emergency, continualshaking case can be promoted.C、For the purpose to evaluate the effects of heat effect, heat shaking duringshaking on friction properties of wet brakes, a analysis model about thermal-mechanical coupling of friction pair was established by analyzing mechanism of braking shakinginvolving the combination of temperature, stress and time-frequency. The effect ofshaking phenomenon caused by temperature, stress changing and thermal-mechanicalcoupling on friction stability.