Posted by Bill S. on April 19, 2000 at 13:49:20:
In Reply to: Crowned bevel gears posted by Andrew Dimitriou on April 18, 2000 at 18:26:13:
If you are asking about crowning straight bevel teeth to reduce tooth bearing along the pitch line, Gleason's No. 104, 114, and 24 machines create straight bevel gears with crown. Gleason's term for this is Coniflex bevel gears. There are probably other Gleason machines that can produce crowned teeth on straight bevels.
Spiral bevels also exhibit a contact pattern, or bearing that varies in length and width. This contact pattern can largely be controlled via tooling choice and machine settings.
When I say "controlled", I don't mean to say that any contact pattern or length is obtainable. This depends on a number of factors, such as tooling choice, gear ratio, gear dimensions, and machine settings. In some cases, it is impossible to get tooth bearing down to a desired 60-70% of face width. This is especially true as face width decreases.
I don't know about specification, but normally when a summary is produced, the bearing is specified in percent of face width, where machine settings and tooling control the bearing length achievable. Normally, a 60-70% bearing is ideal.
Hope This Helps.