GM-04 A STUDY ON FORGING OF SPIRAL BEVEL GEAR OF ARBITRARY AXIAL ANGLE(MANUFACTURING OF GEARS)

This study reports the method of forging of spiral bevel gear of arbitrary axial angle. In the case of spiral bevel gear, line contact of pinion and gear tooth surface should be changed to point contact to avoid wrong performance of power transmission. The authors made two ideas for crowning of gear tooth surfaces to obtain point contact for forging gears. One idea proposes that the trace of the contact points on pinion and gear surfaces lies along the tooth profile of pinion and gear surfaces, namely the trace lies perpendicular to the lengthwise direction of gear tooth. The trace can be set arbitrarily on the gear tooth. The other idea can be used for the trace of contact points on pinion and gear surfaces lies along the direction of tooth trace of the gear teeth. The numerical data are calculated and used for CAD/CAM systems for processing the metallic mold for forgoing of spiral bevel gears. Tooth contacts of forged gear set are confirmed by the 3D drawing of tooth surfaces. Master gears of electrode to work metallic mold to forge a pair of spiral bevel gears were made and running test and tooth contact testing. The running test shows the low noise running and contact mark coincide well with the contact mark calculated and drawn by 3D expression by the theory proposed in this report. And the authors succeeded in forging of the pair of pinion and gear by the two method by the idea proposed in this paper.