The Research On The Mechanism And Restrain Method Of Guideway Stick-slip Friction

Traditional metal to metal contract type of machine tool guideway though has many advantages, but its low speed stick –slip friction problems restrict its application in precision machine tools. Compared with other contact types such as metal to plastic, metal to oil film guideway found that the guideway although don’t have the disadvantage of low speed stick –slip friction, but have no advantages to metal to metal guideway in other respects. So this article research goal is to solve the problem of the low speed stick –slip friction on the base of keeping original advantages of the metal to metal contact type guideway,make it can be applied to CNC machine tools.At first, this paper make physical model, mathematical model, simulation model to lay this foundation for analysis of theory. Physical modeling simplify the feed system. Mathematical modeling obtain mathematical expression by mechanics analysis on the physical model. Simulation modeling solve the problem of the friction simulation modeling first, then construct the simulation system used in this paper by using simulink according to the mathematical model, and make the simulation data processing program.Though the Theoretical analysis this paper study the guideway stick-slip friction in the order of the single degree of freedom motion, the single degree of friction motion and guideway stick –slip motion by analyzing the phase track diagram generated by simulation system and theoretical derivation.the study showed that the stick-slip friction phenomenon has two cases, soft incentive vibration and hard incentive vibration. This paper deduced the critical speed formulas of the two cases and the formulas are validated by computer simulation to be correct in some degree. Then the methods that can eliminate the stick–slip friction phenomenon were studied based on the critical speed formulas. After the analysis of the conventional method, this paper found a new method to change the friction characteristics by changing the direction of friction according to the nature of the friction. This paper completed the structure scheme of the guideway design based on the principle of this method, and analyzed the possible advantages and disadvantages in its applications. The analysis showed that this method is very accord with the aim of this article. The simulation also showed that this method is very effective in inhibition of guideway stick –slip friction.