Rolling screw mechanism in the drilling and milling machine

Abstrakt

Machine tools manufactured in the second half of the 20th century, such as drilling and milling machines, are still in use and working today. In terms of machining accuracy they cannot complete with the new machine tool, as the level of technology in the years of their manufacture was for behind that of today state of the technics. At Present, there are many “SKODA” drilling and milling machines manufactured in various years of the 20th century in use in Poland and other countries. In the machining process, important advantages of machine tools are: rigidity and the ability to damp vibrations. Above all, both of these advantages and more are present in the above-mentioned “SKODA” drilling and milling machines, which is why they have been in use for so long.

Improvements in the machining accuracy of these machine tools can be achieved by retrofitting them to a greater or lesser extent. This article presents a partial modernisation of a “SKODA” drilling and milling machine, type WD200B, built in 1972, involving the replacement of Tr90x20/2 trapezoidal thread screw with an 80x10Rx6,5-6 screw and roller mechanism, which serve to move the headstock vertically along the guides.

The material in this article presents a concrete design solution, made and implemented according to the above-mentioned modernisation. The correctness of this application is confirmed by the results of headstock positioning measurements made between 2009 and 2019. The dissemination of such a solution can only take place after the machine tools has been in operation for an appropriate numbers of years, as has been demonstrated.