Inspection of press joints based on the analysis of their deformation patterns under local thermal loading

Abstract

The results of experimental studies of the possibility of using strain gauges under local pulsed thermal loading to evaluate the tension of the press connections of bearing rings with shafts are presented. Samples of press joints with tightness in the range from 38 to 118 microns were made. As a result of the study of the patterns of heat flow propagation in bearing rings and tension samples by contact method and means of thermal imaging, the possibility of separating deformations associated with the influence of temperature on the deformation measurement area and the temperature gradient in the heating area is shown. The methods of inspecting the press joint when exposed to a heater ring with a heat power capacity of 80 kJ and a temperature of 200°C and measuring the deformations of the ring and shaft by an opto-polarizing sensor with a base of 60 mm and a resolution of 2×10 — 7 relative deformations have been experimentally implemented. A correlation has been established between the time of reaching the maximum of local deformations of the shaft with the tightness of the press joints and the sign of deformations of the bearing ring with the tightness of the press fit, the gap between the ring and the shaft.