A method to manufacture spiral bevel gears by equivalent completing

Abstract

As a transmission part for industrial application the manufacture of spiral bevel gear is particularly important. The present machining methods for manufacturing spiral bevel gears, including the so called five-cut method and completing method, have drawbacks such as low processing efficiency, requiring complex calculations and high requirements on the machine-tool performance, respectively. To solve the above problems, an equivalent completing method is proposed to process spiral bevel gear in this paper. Firstly the machine setting parameters by completing were translated from the Cradle-type hypoid generator to Cartesian-type hypoid generator and the workpiece is swing during process. CNC motion axes expression of Cartesian-type hypoid generator were expressed as sixth-order polynomial, the influences of coefficient on the tooth surface topology were researched. Then the method to machine spiral bevel gear was put forward by reducing the swing axis of workpiece, obviously a deviation of tooth surface was caused between theoretical and axis-reduced. As a response, a flank correction model was established and the other polynomial coefficients were adjusted to eliminate the deviation. Finally simulation and cutting experiment were carried out by a numerical example. The experimental results show that the proposed method is effective and feasible. The method proposed in this paper overcome and enrich the disadvantages of existing manufacture methods of spiral bevel gear.