Tez özetleri Astronomi ve Uzay Bilimleri Anabilim Dalı

Computer Simulation Of Spur And Helical Gears

In this licentiate thesis titled “Computer simulation of spur and helical gears”, solid modeling of involute gears which is the first step of computer simulation and further numerical analysis first step of them have been studied. An accurate geometrical representation of gear tooth surfaces is the fundamental starting point for developing a reliable computerized gear design which includes numerical methods for stress analysis. Based on analytical mechanics of gears, parametric equations describing involute profile and root fillet profile of the gear teeth have been presented in literature. The matematical model used in this thesis is based on Litvin’s Vector Approach which provides accurate representation of tooth geometry. By applying the equations of designed profile of rack cutter, the principle of coordinate transformation, the theory of differential geometry, and the theory of gearing, the mathematical models of involute helical gear are given. Also undercutting of the generated gear has been studied. As an application of variety design, asymmetric involute tooth geometry is considered. This gear type can reduce the size and the weight of gear and increase its load capacity. Computer implementation of the mathematical model is performed with a code written in Matlab programming language. The output of this program consists the coordinates of points which determines gear outline and list of commands that produces automatic generation of tooth profile in AutoCAD solid modelling software. Computer graphs of generated gears are obtained for two and three-dimensional gear geometry. Besides, the simulated motion path of the generating cutter is illustrated. The program has been run for different design parameters and the effect of pressure angle, the degree of asymmetry, and the addendum modification on the generated tooth profile have been investigated using the computer graphs of helical gear with asymmetric involute teeth. The results are compared and discussed. As a result we can say that, the matematical model and the proposed computer programming approach help us to investigate the effect of rack-type generating tool parameter on the generated tooth profile before manufacturing. For further studies, the proposed computer simulation based on the invesitgated mathematical model can be used for finite element modelling of asymmetric involute gears.

SEZGİN Aziz

Danışman : Prof. Dr. Nurkan YAĞIZ

Anabilim Dalı : Makina Mühendisliği

Mezuniyet Yılı : 2009

Tez Savunma Jürisi :

: Prof. Dr. Nurkan YAĞIZ

: Prof. Dr. Salim ÖZÇELEBİ

: Prof. Dr. Ahmet SERTBAŞ

: Doç Dr. Erol UZAL

. Doç. Dr. Recep BURKAN