12.10.2016 Pressing & Sintering

Testing and validation of powder metal gears in a 6 speed manual transmission

A 6 speed manual transmission was redesigned and optimized for using powder metal steel as the gear material. The design work was very comprehensive and included deformations of housing, shaft, bearings, bolts and gears and varying temperature conditions. The analysis showed that powder metal (PM) gears would survive the durability cycle despite that no densification methods were used. In the second phase of the project, a SAAB 95 was equipped with a prototyped gear box according to the PM optimized design and 3 transmissions were built and tested in test rig for durability and vibrations. This paper will demonstrate the testing procedure and the results from testing. The transmission has also been benchmarked with the original transmission and comparisons have been made. Lessons learned will be discussed and how the design can be improved in future transmissions.