Thread: Gear Woes
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Unread 24-01-2002, 09:11
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Quote:
Originally posted by Dreistul


I'm a little confused with this equation. What is FTooth? Is that supposed to be the force applied to the tooth, (in other words, FTooth=Torque/GearRadius?)

Also, by using this equation, does it mean that the speed at which the gear is turning does not have bearing upon the amount of stress applied to the gear?


Thanks for the help!
1) FTooth is the linear force at the tip of the gear tooth. So, you are correct that FTooth = Torque/GearRadius

2) This equation does imply that the speed of the turning gear has no bearing on the stress in the gear. Carl Barth (19th century) introduced the "velocity factor" for gears to take into account increased stress at high RPM. However, it is not a very exact calculation and I don't think it's worth worrying about for the short cycle times that our robots live through. Just use Joe's equation and give yourself a good safety factor and you'll be fine.