Abstract: The thermal deformation model of cutaway disk is proposed for automatic brake adjuster based on its mechanical model. This model can solve the geometrical relationship between cutaway disk and the self-adjust clearance increment, illustrate the thermal deformation law, and calculate the self-adjust clearance increment caused by the thermal deformation of cutaway disk. A self-adjust performance test system of automatic brake adjuster with a multiple incubator is set up to dynamic test the clearance increment in varying temperatures. The experimental result with seven groups of trials shows that the relative error range is [0.01, 0.13]. Comparing with the true values, the grey incidence degree of our suggested model is 0.98 while that of FE model is 0.92. The mean absolute errors are 0.14° for our suggested model and 0.53° for FE model. It indicates that our suggested model is approximate to FE model both for accuracy and veracity. What’s more, our suggested model is more suitable for measuring application because it is easy to build comparing twith FE model.

Key words: automatic brake adjuster, cutaway disk, grey incidence degree, self-adjust performance test, thermal deformation