MANUFACTURING OF THE TRACTION DRIVE WITH THE GLASS-FIBER EPOXY COMPOSITE-MATERIAL

Abstract

A new traction drive mechanism, which delivers power from its input shaft to its output shaft using friction produced by the elastic ring, was designed and manufactured with the glass fiber epoxy composite material. The major speed reduction of the traction drive is originated from the circumferential difference between the flexspline and the elastic ring, which is 1 similar to 10 % of the circumference of the elastic ring. Then the speed reduction of the flexspline is 10 similar to 100 times. The flexspline in the traction drive should be flexible in the radial direction to produce the friction between its surface and the surface of the elastic ring but should be stiff in the tangential direction to transmit accurate rotational motion. Since the conventional isotropic materials such as the steel and the aluminum cannot meet these stiffness requirements simultaneously, the glass fiber epoxy composite material was adopted to directionally tailor the stiffnesses. To eliminate wear of the composite flexspline, a thin ring of the same axial length of the elastic ring was manufactured with the high strength steel and adhesively bonded to the flexspline. The stress of the composite flexspline was calculated by finite element method and the assembled traction drive was statically and dynamically tested in order to assess the vibration and fatigue characteristics.