An Investigation of the Effects of Lubricant Viscosity, Surface Finish, and Clearance on machine Tool Slid-way Damping and Friction

摘要

The role of a machine tool structure is to support the machine tool and the workpiece under the action of various, mainly cutting, forces. These forces forces often result in unacceptable levels of vibration of the tool and workpiece. mechanical joints are the primary source of damping in most passive structures. Therefore, vibration reduction and energy dissipation characteristics of machine tool joints is of great interest. In a large lclass of machine tools, either the workpiece and/or the tool translate along slideeways. Design of these joints is critical to the machining performance. Understanding the effects of the mechanical interface parameters (lubricant viscosity, saddle/silideway clearance and slideway surface finish) is needed to acieved appropriate balance of mechanical peroformence (friction, energy dissipation), environmental sensitivity (type and amount of fluid) and economic concerns. Experiments were conducted to analyze these parameters. Specifically, four lubricant conditions were investigated, dry (nolubricant) and three commercially available lubricants (spanning a broad range of viscosity). l(nitial investigation showed minor differences between the three lubricants (damping is primarily viscous and of similar level, but significant difference between dry (primarily structural damping).) The effect of machined versus ground slideway did not show markedly different energy dissipation characteristics. The investigaton of clearance showed some effect on the damping behavior.