The value of powder metallurgy in the automotive marketOctober 14, 2021
MPIF awarded a grand prize in the automotive chassis category for conventional PM components to Phoenix Sintered Metals LLC. and customer Dana Incorporated, for a stepped planetary gear used in a ridged rear axle gear box for battery electric light commercial vehicles. To enable an 82:1 dual reduction planetary gear system, it was essential to be able to deliver tight dimensional control for this complex shaped part. The five-level pinion is made using FL-4405-100HT. The parts have different, fine gear tooth geometries at each of the ends; one end has a 15-tooth, 0.72 mm module, while the other an 18-tooth 0.555 mm module separated by a thin guiding flange that is also used for orientation during assembly. Both gears exceed the ANSI/AGMA 2000-A88 class 7 requirement and both gear forms maintain 1.33 CPK for 0.075 mm runouts to the bore. The pinion is oil impregnated. This provides lubricity while running and lower torque loss at start up and in cold weather conditions than grease. The concept of a dual reduction planetary gear system was possible because of CNC powder compaction. No other metal forming technology could provide the part geometry at a commercially competitive price. Dana performed bench testing for functionality, durability and abuse at the sub-system level. The end customer performed vehicle level testing for performance, durability, reliability and NVH. The test duration for each phase was typically four to six months to complete the required battery of tests.