Investigation of externally toothed parts forming using ballizing technique

Abstract

Externally toothed parts such as gears, splined and coupling sleeves can be manufactured by machining, casting, and forming. The machining process is costly because of using a special tool, consuming power, and wasting material during the machining process. The casting processes usually need other finishing processes. In this study, a new forming tool based on the ballizing technique is suggested to perform the forming of the toothed parts with external splines in one stroke. The set is made up of six steel balls each having a 20 mm diameter. The process was performed on the lathe machine with data acquisition recording to record the process consumed load. Die with splines on the inner surface opposite the required splines was mounted in the lath check. The required tooth shape was obtained by forcing the forming tool into the hole by pushing the specimen into the die cavity. the mathematical model was formulated to calculate required force deformation. The model depends on the process dynamics and contact area between the tool and the specimen. The effect of process parameters on the load and the product properties was conducted. The study parameters were forming depths of 2, 3, 4, and 5 mm, the rotational speed of 50, 76, 120, and 150 rpm, axial feed 0.1, 0.15, 0.3, and 0.6 mm/rpm specimen inner diameter of 66, 64, 62 and 60 mm. A comparison was made between results of mathematical model and results of experimental. Rotational speed, axial feed, and cross-in feed were found to be the three factors that have the greatest impact on forming load and overall product quality. Also, it was found that deformation load increased with the increasing rotational speed, cross-in feed, and axial feed.