The study of shape error formation regularity in the plunge centerless grinding of driveshaft cross-piece journals based on the thermal state of the machine and temporary stops

The paper presents the research results of shape error formation regularity in the plunge centerless grinding of driveshaft cross-piece journals according to the thermal state of the machine and its temporary stops. The results provide decrease in the shape error of driveshaft cross-piece journal surfaces. The paper presents the dependences of shape error change (ellipticity, faceting) on the machine thermal state and its temporary stops. Various conditions of the machine thermal state (the state of long-term heating, the state of long-term cooling, the state of overnight stops) have been studied. The measurement of shape error parameters have been performed by means of the circularity meter. A number of circulargramms have been recorded under certain recording increase and their further processing. The results of the research are presented as guidelines for the use of technology in driveshaft cross-pieces production. It has been experimentally proved that the machine thermal state effects the shape error formation in driveshaft cross-pieces grinding. Being in the state of thermal balance, the machine provides greater shape precision in driveshaft cross-pieces centerless grinding.