Densification Processes Helps Drive Growth
In recent years, gears produced by PM have significantly closed
the gap that once existed between PM and wrought gears.
According to George Shturtz, Sales Manager at MPP’s Ford Road
Division, “They’re not your father’s PM gears anymore.”
PM gears now achieve ultimate tensile strengths of 190,000 psi (or better) and, through the use of additional processes such as gear rolling, can also achieve AGMA ratings of Q10. In gear rolling, a near net-shape PM gear is rolled with an optimized master gear to the point where the resulting PM gear attains an accuracy that is comparable to that of the master gear. Other factors affecting PM gear quality include the more accurate molds that are possible with techniques such as wire EDM, and the use of higher-tonnage and more sophisticated presses such as the 880-ton, computer-controlled press recently installed at Ford Road.
Specifiers of gears often refer to NVH (Noise-Vibration-Harshness) as something that they want to eliminate –or at least minimize– in the gears they purchase. Surface densification is a process that can help minimize NVH and, generally, improve the quality and performance of PM gears.
MPP has a significant advantage over traditional “press and sinter” PM gear manufacturers because of its innovative, proprietary PCF (Precision Cold Forming) process. PCF is a combination of several technologies that can produce PM gears that match the performance of cut wrought gears. In a series of accelerated life, test track, and other tests, PCF-produced PM gears exceeded test goals and with minimal wear and provided better fatigue properties than wrought gears.
As the quest for stronger and more accurate PM gears continues, MPP will continue to be one of the leaders.