A New Successive Forming Process for Large Modulus Gears

Abstract A successive tooth forming process for producing large modulus spur gears (m＞2.5 mm) was firstly proposed in this paper to break the restrictions of large forming load and large equipment structure of traditional plastic forming. It contains the preforming stage and finishing stage. In the first stage, the die with a single-tooth preformed gear teeth one by one through several passes. In the second stage, the other die with multi-teeth refined the preformed teeth into required shape. The influence of total pressing depth and feed distribution in preforming stage on final forming quality was analyzed by numerical simulation and the reasonable process parameters had been presented. Gears without fold defects were well formed both in simulations and experiments, proving the feasibility of this method. The new process has advantages of smaller forming load and simpler tooling set, which shows a good potential for manufacturing large modulus spur gears.