I really appreciate all the advice from everyone. Sorry for the delayed response. To answer some questions:
Speed and load: During normal operation, the max loading for the gear occurs at stall (0 RPM) where bending stress can reach ~250MPa according to Lewis formula. The gear can go as fast...
Thanks to everyone for the responses so far. We are still leaning toward changing the material to a low-alloy steel (SCM415) and carburizing or carbonitriding the teeth. Will this help at all? I've included a few more photos of a second sample of the same gear that also failed the same...
Israelkk, the assembly is mounted on a vehicle so our vibration tests are based on ISO 16750-3: Road vehicles—Environmental conditions and electrical testing for electrical and electronic equipment, Mechanical Loads.
Dinjin, the mating pinion has 9 teeth and is profiled shifted by 1.1. There...
A spur gear exhibited a broken tooth during a vibration test. The vibration of the overall assembly translated to an unknown input torque on the shaft of this gear which resulted in it impacting its mating gear in both directions. The rotation of the mating gear is ultimately constrained by a...