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Outline Factor or Tooth Form Factor?

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PhilipFry

Mechanical
Joined
Aug 3, 2001
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56
Location
US
Okay, I have a gear train that was designed by an engineer some time ago. Problem is, I can't find any documentation (if there ever was any) to help me determine the performance of the system. Therefore, I'm trying to use the Lewis Formula to come up with a rough idea of the required yield strength that the gears must have for an applied load. The only variable I lack is the "Y" factor...known as the "Outline factor." I've looked in the Machinery's Handbook 26th ed, but was only able to find "Tooth Form factor (Y)" for plastic gears. Where can I find this info for metal gears?
 
The Y factor is the same for all materials.
The basic formula Wn = SbY/Dp
Stress varies from steel plastic and other materials.
Y is a constant based on a 1 Diamtral Pitch Gear System.

Dp = Diametral Pitch
Y = Tooth Form Factor at the tip
Wn = Normal Tangential Tooth Load
S = Allowable Stress (Roughly the UYS/3)
b = gear face width

UYS = Utimate Yield Stress
 
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