# Bevel Gear Tooth Profile

• 10-21-2020, 04:11 PM
scott_carpenter
Bevel Gear Tooth Profile
[COLOR=#333333]I'm designing a small set of plastic bevel gears, but am having a hard time getting the tooth profile right. I used the equations from the KHK website below to define the gear blank, but there is no information on tooth profile. Because of that, I modeled the teeth using the spur gear profile sketched in the plane normal to the pitch cone angle. I've gone over my sketch and calculations a few times and can't find any errors, but the teeth aren't even close to meshing. I used the module and teeth count of an actual set of gears, so I know it should work out. Any suggestions here? I'm using Creo 3.0[/COLOR]

[URL="https://www.engineersedge.com/engineering-forum/attachment.php?attachmentid=2511&d=1603285647"]Calculation of Gear Dimensions.pdf[/URL]

[URL]https://www.mcmaster.com/2515N318/[/URL]

[URL]https://www.mcmaster.com/2515N325/[/URL]
• 10-22-2020, 07:12 AM
jboggs
I have dealt with a number of special bevel gears over the years, and I haven't seen any of your calculations. That said, my first impression of the picture is that whatever factors in your calculations affect the "fatness" or width of the green teeth at the pitch diameter result in teeth that are too broad. It would have been helpful to see a representation of the pitch diameter in that picture. Are you sure you are actually meshing them at the PD tangent point?
• 10-22-2020, 08:30 AM
scott_carpenter
I'm using the equations from the website below, which are virtually identical to the equations in the machinery handbook. I ended up figuring it out. when calculation the tooth thickness, I was using the pitch diameter of the virtual spur gear shown in figure 4.9 in the link below, but I should have been using the actual pitch diameter of the bevel gear.