Posted by Allan Guest on December 27, 2009 at 13:00:22:
In Reply to: Modified Roll Method for Spiral Bevel Gear Manufacturing posted by Cevat Ceyhun on December 24, 2009 at 02:59:00:
Modified roll was initially designed by Gleason for the use on grinding spiral bevel and hypoid gears; therefore pre-grind cutting had to preceed using the same method but using face mill cutters on a cutting generator .
No tilting of cutter or grinding wheel is required with this method.
The gear (or crownwheel) is finished cut by the SPREAD BLADE METHOD (SB) with no modified roll. The pinion is finished cut using modified roll which eliminates bias.
It works by the cradle roll of the generator to either speed up or slow down during cutting or grinding from one end of the tooth (say toe end) to the other end (say heel end ) while the work piece is moving with uniform roll . In other words the cradle roll would be accelerating or deccelerating during generation of gear tooth .
I hope this is of help to your question .