Innovative Systems Design and Engineering www.iiste.org ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online) Vol 3, No 6, 2012 53 Simulation of Generation Process for Asymmetric Involute Gear Tooth Shape with and without Profile Correction Mohammad Qasim Abdullah* Department of Mechanical Engineering, College of Engineering, University of Baghdad, Baghdad, Iraq *E-mail of the corresponding author: mohq1969@yahoo.com Muhsin Jabir Jweeg Department of Mechanical Engineering, College of Engineering, Al-Nahrain University, Baghdad, Iraq E-mail: muhsinjj@yahoo.com Abstract In order to achieve any design study on a gear tooth or to carry out any type of analysis on a complete gear drive, the first step is the representation of the actual form of this tooth under consideration. In this work, a mathematical simulation of generation process for the symmetric involute gear teeth shapes based on the principle of the gear shaping process with a rack-shaped cutter has been developed to take into account the effect of asymmetric tooth profiles and the use of profile correction on each side of tooth with different design parameters for each side of tooth. As a result of this work, a computer program based on this mathematical simulation has been built to represent graphically step-by-step the actual form of symmetric and asymmetric gear teeth shapes with and without profile correction for different gear design parameters. Keywords: Involute Gear Teeth, Symmetric, Asymmetric, Profile Correction, Mathematical Simulation, Generation Process. 1. Introduction In this work, the principle of gear shaping process with a rack-shaped cutter which is one of the gear generation methods [1], has been adopted to simulate mathematically the generation process of involute gear teeth shapes. By this process the tooth profile obtained is composed of two well defined parts, the involute part and root fillet part. The involute part is generated by the straight sides of the rack cutter, whereas the root fillet part is formed by the cutter nose. In this mathematical simulation, two cases have been considered, the first case is for the generation of symmetric tooth shape and the second case has been developed to generate asymmetric involute gear teeth shapes with and without profile correction (profile shift) for different design parameters of module and number of teeth on gear, as well as pressure angles, root fillet radii, top edged radii and correction factors for loaded and unloaded tooth sides. 2. Generation of Symmetric Tooth In the generation process of symmetric tooth shape, the generating rack cutter and gear blank roll in contact in timed relation to each other simultaneously, they are also given a feed relative to each other to remove the metal from the blank. In this process, the cutting tool (rack cutter) which shown in (Figure 1) is given a shape conjugate with the form of the tooth to be cut. Therefore; the geometrical representation of the rack cutter with its rolling simulation are imperative. 2.1 Geometrical Representation of Rack Cutter The basic rack cutter which is shown in (Figure 1) has been adopted as a cutting tool for this generation process [2]. Fifteen points are used to define the outer shape of this rack cutter. The Cartesian coordinates of these points are measured with respect to a reference point which is located on the pitch line . Referring to (Figure 1), it can be that: from : (1)