A novel technique for driveline assembly applications

A novel technique for drivetrain assembly - Mill-Knurling and Press-Fitting (MKPF) is projected as a substitute to laser welding or bolting. This joining practice involves the press fitting of two mating surfaces, one with mill-knurled teeth and the other which is of a comparatively softer material, enabling it to stream over the teeth making a joint. This process has been applied within an automobile rear axle differential which is subjected to random torque loads. Experimental analysis and simulation has been used to evaluate the serviceable viability and the latent benefits of mill knurled joints with both laser welded and bolted joints currently used by BMW. Assumptions such as total cost of planning, research and development, total investment, total specific resources, raw material and manufacturing costs were used to evaluate mill knurling as an alternative to laser welding and bolted assemblies. The MKPF method has been successfully applied to assemble rear axle differential cases to the bevel gears. The costs, weight and size estimations are very positive in comparison to the competitive methods of laser welding and bolting. The noteworthy weight saving will strengthen the efforts by the automotive industry to reduce the emission levels of vehicles. The pitch flank deviation values which are critical for the life cycle duty of the bevel gear need to be further investigated in order to achieve comparable results with laser welding.