Increasing spur gear durability: two-material spur gear

摘要

A new design method to improve durability of spur gears made of low tensile strength material is utilised. In this method the gear is made of two materials, where most of the gear body is made of low tensile strength material 'like gray cast iron or aluminum', and only teeth fillets are made of high tensile strength material 'like steel'. The method shows promising results; all maximum stresses carried by the gear body 'weaker material' and the maximum tooth tip deflection are significantly reduced. A computer code using boundary element method is written to find gear stresses. Computations carried out by the present code have been verified by comparison with COSMOS/M (Version 1.75) package computation. To simulate two materials body, two pieces made of cast aluminum with circular steel inserts are fabricated. The experimental tests show that failure takes place in the aluminum region.