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Unread 01-06-2014, 17:48
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Re: Turning down the OD of a gear

Quote:
Originally Posted by Rauhul Varma View Post
Wont removing that outside bit increase the stress per tooth?
Absolutely.

Involute gears do not simply contact at the pitch diameter the contact moves from the tip to the root along the line of action as can be seen on the previous graphic. Gears all have sliding contact and most have at least one place on the line of action that has pure rolling contact. A gear mesh has three distinct actions during mesh. When a tooth begins in contact it is called the approach action there is a combination of sliding an rolling on the mating surfaces. When the contact along the line of action passes through the pitch diameter there is an instant of pure rolling. Then the contact goes into recess action where there is a combination of sliding and rolling once again. A shift in center distance will not change the fact that the contact will move from the tip to the root along the line of action it will simply make the line of action shorter and change the amount of backlash.