Friction Variances of Linear Machine Tool Axes

Friction and damping have a wide influence on machine tools’ dynamics. The statistical spread of identical machine tools’ friction and components’ influence on it are marginally known. In order to reduce this lack of knowledge, measurements of friction in linear axes of identical machine tools were performed.In the course of this paper the variance of friction in a single axis is determined as well as the difference between several machine tools. Different types of feed drive systems, ball screw and linear motor driven, are measured and compared. The measured friction curves are used to estimate parameters of an extended Stribeck friction model.As a result, a method of measuring and analyzing friction in machine tools is developed and the evaluated parameters can be used for observing the assembly process, for condition monitoring, for on-board diagnostics and for scatter based parameterization of simulation models.