Quote:
Originally Posted by Tristan Lall
Is that strictly correct? I would say that doing so changes the stress distribution (because the non-meshing parts of the gear teeth will resist bending). While some stresses may well be locally slightly higher than in the same-width case (I'm thinking right at the edge of the meshing tooth), on balance, the amount of stress at a given point in the wider gear ought to be lower, thanks to the contribution of the extra material.
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I agree. I think a more accurate assessment would be that you can absolutely make one gear wider, but only the contact width will provide the strength you need, so making the gear wider than the contact area does not allow you to make the gear weaker (or maybe it does ever so slightly, but that's probably not a good way to do the design...). I'm not seeing how increasing the size of one gear ever increases the pressure on it...
To cite reality, CIM pinions are almost always
5/16" 5/8" face width, while the standard 20dp gears (both from AM and from lots of other suppliers) have a
3/16" 3/8" face width. This difference means you can still line up the gear and pinion after pressing the pinion onto the CIM shaft with little to no accuracy in terms of how far it's been pressed on.
Edit: heh, not sure what I was thinking... sixteenths are small....