INCREASING THE LOAD CAPACITY OF GEAR BY DRILLING HOLES ON ITS TEETH

A new approach to strengthen the spur gear by drilling holes on the blank of the gear is proposed. The holes are able to reduce the stiffness of tooth and improve the capability of heat transfer.FEM is adopted to calculate the stress and stiffness of tooth of the gear with and without holes and then a procedure according to GB3481-83 is implemented. The results show that the contact stress is about 7% lower and the bending stress about 11% lower than that of the conventional gear. The vibration and noise can tie reduced as well. The optimal dimension of the hole for a standard gear is 1.4m from the tip of the tooth and 0.6m (m-module) as its diameter. The proposed method is more practical for spur gears of larger module and the life of the gearing may be as two times long as the normal one under the same conditions