16.10.2001 Pressing & Sintering

Surface Densified P/M Transmission Gear

The International Conference on Power Transmission Components, in Ypsilanti, Michigan, USA. Arranged by MPIF. Authors: Sven Bengtsson, Linnéa Fordén, Senad Dizdar, Pernilla Johansson. Progress in development of a surface densified P/M transmission gear is reviewed. The gear is the fifth gear of a manual transmission for a medium sized passenger car. Blanks were produced by hobbing of pressed and sintered slugs. Densification of both the root and the flanks of the P/M gear was achieved using gear rolling technique. The rolled gears were case hardened. At present the development stage, the quality of such the gear is close to AGMA class 10, which is considered to be the required level for automotive manual gearboxes. The surface roughness is better than for the shaved reference gear. The hardness profile in the flank region matches the hardness profile of the wrought reference gear; and finally, the desired density distribution was reached.