Experimental Design and Manufacture a Pair of the Internal Non-circular Gears with an Improved Cycloid Profile

Abstract

AbstractThe idea of non-circular gear (NCG) has been known since the 14th century but has spent a long time receiving little attention due to design difficulties and no efficient machining methods. Research on NCG has been interested in the early 20th century and applied in almost all fields to generation derivative function drives to replace traditional complicated mechanisms. In this paper, the authors present a method to design a pair of internal NCG generation eccentric gear, and an NCG with tooth profile is an improved cycloid curve. First, the rack cutter shaping the eccentric gear with tooth profile is an improved cycloid curve. After that, the tooth profile of NCG is generated to the planar meshing theory when the centrode of eccentric gear rolls without slipping inside the centrode of NCG. In designing to avoid undercutting conditions, the tooth number distribution on the gears for selecting the rack cutter parameter is also considering to ensure the generation tooth profile. A numerical calculation program on Matlab has been programming to calculate and survey the design. On that basis, a pair of internal NCG has been designing and manufactured on a 3-axis CNC milling machine to illustrate the design approach.KeywordsInternal non-circular gearImproved cycloid profileUndercuttingRack cutterShaper cutter