MEASUREMENT OF THERMAL DEFORMATIONS OF AUTOMATIC FACE GRINDERS AND THEIR INFLUENCE ON THE OPERATIONAL ACCURACY OF BEARING STEEL PROCESSING SHH15

Abstract

The article measures the thermal deformations of the face grinding machine in order to ensure the required level of geometric accuracy of roller bearing rings and reduce the number of defects during the production of rolling bearings. The end surfaces of the bearing rings are treated using powerful electric drives from 25 to 50 kW, a significant part of the electrical energy is converted into heat and absorbed by the technological equipment. It is impossible to neglect such an influence in order to ensure high geometric accuracy of processing bearing rings, which is characterized by units and tens of microns, because heat is dispersed unevenly and requires a quantitative assessment of thermal deformation resistance for the correct adjustment of production equipment in order to ensure high dimensional stability of the processed workpieces.

It was established that under the action of thermal deformations of the units of the face grinding machine, the abrasive cutting tools change their position in the vertical and horizontal planes. Stabilization of the position of the abrasives has a different time range depending on the heat source: from spindle supports - within 2 hours, from lubricating and cooling liquid - after 5 hours. In the general balance of thermal deformations of the face grinding machine, the displacement of the grinding wheels caused by the change in the temperature of the lubricating and cooling liquid is within 75-80%. The change in the position of the flanges of the spindles of the face grinding machine during 5 hours of work in the vertical plane amounted to 59 μm and is the reason for the non-parallelism of the ends of the rings.