Can't really describe it without divulging more than I'd be comfortable - suffice to say the downstream gearbox components have to be able to move around a shaft, fixed or otherwise, but we gain very little with a rotating shaft and have a large number of negatives (including increased weight...
@Tmoose -
The gear is attached to the "hub", which rotates around a fixed shaft. the bearings are pressed into the hub (m6 fit) and g6 on the shaft - fairly standard for outer ring rotating load conditions. It does reduce life but we're not limited by these bearings so it's not a big...
Sorry, should clarify - the gear bearings are 1% of CoR (and have a CoR 4x higher than the motor bearings). They're deep groove ball bearings, and are preloaded to ~3-5% of CoR. This is set by the motor manufacturer, and we've been informed we can't change out the bearings for an angular...
We have a few different sets, but one example set:
Teeth: 30/96
Normal Module: .45357 (56tpi)
Width: 5mm
Trans. Pitchline Velocity: 1.4 m/s Max
Center-to-center: 29.2 after addendum modification.
Normal PA: 14.5deg
Helix ang: 14 deg (and this is higher than we'd like already for bearing life)...
We've already pushed a lot of those around - 14.5 normal pressure angle, tip relief, etc. Crowning may be something we should look into. We're manufacturing to AGMA Q10 right now, I'm not sure my gear supplier can get any better (and we're locked in there).
Structural modes don't seem to be...
I'm getting significant pushback from management and our vendor about the need for helical gears to have an axial/overlap contact ratio of greater than 1 for best performance. Our vendor says it won't help noise as long as the transverse ratio is over 1.5, and management doesn't want the longer...
