The effect of adding nano size clay particles on the dimensional characteristic of POM composite gears

Plastic gears possess wide range of applications in transmissions. The advantages of polymeric gears include low weight, low cost, good resistance to corroding conditions and the ability of running without external lubrication and having lower noise compared with metallic gears. However the drawback of pure plastic gears include limited mechanical properties as well as dimensional errors and nonuniformity. In this investigation different compunds of POM(poly acetal) and nano clay comprising 1, 3, 5 weight percents of nano clay were prepared by using a twin-screw extruder. Subsequently, pure and nano composite gears were molded by applying injecton molding process. The incorporation of nano clay into POM significantly affected the MFI rate. The pure and composite gears were characterised in terms of dimensional conditions of gear teeth by applying an advanced gear measuring system. The results of experimentations indicated that the addition of nano clay influnces the dimensional characteristics of the gears including the teeth profile, form and teeth angle of the composites gears. The incorporation of nano clay into POM matrix led to a 30% reduction of dimensional errors of POM-nano clay composite gears.

کلیدواژه ها:

polymeric gears ، involute profile ، POM/Clay nanocomposite ، shrinkage