Study on Minimum Teeth without Undercutting of the Spur Involute Gears with 22.5º and 25º Pressure Angle Based on VB

After considering the rack cutter's addendum, the minimum teeth without undercutting of spur gears with 20o, 22.5o and 25o pressure angle were carried out analysis and comparison in this paper. On the basic of gear generating principles, origin and basic architecture of undercutting were presented, and the phenomenon of undercutting was theoretically investigated. And, there also are simulated result by means of VB and experimental results in this paper. The rack cutter is used to infer minimum teeth without undercutting of in volute gears with the pressure angle of 22.5o and 25o, and correct minimum teeth without undercutting are got when the pressure angle are respectively 22.5o and 25o. Then, virtual simulations in the circumstance of software VB are applied to verify the validity of theoretical calculations.