more gear issues trying to understand the math

[idacal]

Im attempting to build a small piece of equipment for my business and Im stuck at how long the gears need to be I was planning on dp 6 33 tooth spur gear running a 100 tooth gear i was thinking my angle would be 14.5 involute (I have the cutters already). was going to use some 4140 that I have for stock. will run it through a heat treat afterwards, Im going to be having 900 ft-lb hydraulic motor driving the 33 tooth gear at 380 rpm it will rarely be at that torque but I need to build for it and some shock loads when the driven shaft overloads. Im trying to understand how to calculate the lewis formula and its making my brain hurt would a 3" long gear handle the torque and give a roughly 5000 hour life span? baring something stupid of course. Im thinking a triple 0 grease lube, or 90 weight moly oil, gears in the lube. if heat becomes an issue I will cross that bridge when I get to it
am I way under building it or way over building it?

 

[Larry Dickman]

this might help

Horspower Calculator

 

[idacal]

well that's to simple thank you. just to clarify so when it says that the torque is 7100 in-lb that is the torque that gear can take per tooth right?

 

[SBAER]

The KHK gear calculator is free

Free Gear Calculator | KHK

If you are designing machinery MITcalc is worth every penny

stan

 

[Maxxx17]

Oddly enough, I saw a similar question on Ohhaskme. Is that where you asked it? You can just use a special calculator like the user above says. I don't understand why you didn't do that right away. Or ask as on that site from those who are good at math. For them it will be like dessert because they love to solve various mathematical and logical problems.

 

[gbent]

You will be better served by 20 degree pressure angle gears, even if you have to hire someone to hob them.

 

[DDoug]

You will be better served by 20 degree pressure angle gears, even if you have to hire someone to hob them.

Heck, go to 25 degrees.

Where's EG ?