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-fit joints in the range from 38 to 118 μm were prepared. As a result of the study of the patterns of heat flow propagation in bearing rings and tension samples by contact method and by means of thermal imaging, the possibility of separating strains associated with the influence of temperature on the strain measurement area and the temperature gradient in the heating area is shown. The methods of inspecting a press joint exposed to a heater ring with a heat power capacity of 80 kJ and a temperature of 200°C and measuring the strains of the ring and shaft by an opto-polarizing sensor with a base of 60 mm and a resolution of \(2 \times {{10}^{{ - 7}}}\) relative deformation units have been experimentally implemented. A correlation has been established between the time of reaching the maximum of local strains in the shaft with the tightness of the press joints and of the sign of strains in the bearing ring with a press fit leak with the gap between the ring and the shaft.