SOFTWARE FOR GENERATING A SPUR GEAR’S INVOLUTE PROFILE AND ALTERNATIVE MANUFACTURING METHOD

Abstract

The paper analyzes the state of the art in regard to methods of manufacturing spur gears differently than the conventional ones such as hobbing, shaping and skiving. Current research concludes that additive manufacturing cannot be used to properly make gears because their profiles require higher accuracy. The most competitive processes have proven to be different types of milling. Most papers present the milling of gears using expensive 4 or 5 axis machining centers with the end mills oriented radially to the blank. The current paper shows that spur gears can be manufactured efficiently form a time and cost point of view by using a standard 3 axis CNC milling machine with conventional end mills. The end mills are oriented axially to the blank and the only limiting factor is the tool’s usable length. A proprietary software was developed to calculate the involute profile of any spur gear using Matlab and a method of generating the CAD model is presented. The machining process was simulated using CAMWorks. A comparison of the costs of the proposed alternative manufacturing method is made with actual spur gear prices and it shows that standard 3 axis CNC machining becomes progressively profitable for gears of large module and/or numbers of teeth.