Contact Stresses for Different Gear Design Parameter


Gearing is one of the most critical components in mechanical power transmissionsystems. This work investigates the characteristics of an Involute gear systemincluding contact stresses. Current methods of calculating spur gear (Non-linearAnalysis), contact stress using Hertz’s equation, which were originally derived forcontact between two cylinders. To enable the investigation of contact problems withFinite Element Method (FEM), the stiffness relationship between the two contactsareas is usually established through a spring placed between the two contacting areas.This can be achieved by inserting a contact element placed in between the two areaswhere contact occurs. A computer program was built up using (MATLAB 6.5). Theresults of the two dimensional FEM analyses from ANSYS are presented. Thesestresses are compared with the theoretical values (Hertz’s equations). Both resultsagree very well. This indicates that the Finite Element Method(FEM) model isaccurate. The results of contact stress analysis indicates that increasing the geometricalparameters (Pressure angle, number of teeth and module) lead to improve the toothcontact stress, with the contact position, because the increasing of the geometricalparameters will results in an increase of the tooth stiffness which leads to decrease thetooth contact stress.