Optimizing Gear Design for Screw Jacks

[vassos_ael]

i have to design gears for a screw jack. i have initial rpm 1500 and final rpm 100. my gear at the point of the power screw is 0.04 m and i want to calculate the diameter for the other 3 gears. can you please help me thank you

 

[OldEngr63]

Sketch up the gear train you need to build, with gear tooth numbers n1, n2, n3, n4 and then write down the equation for the train ratio. Look at your given information to see what the train ratio has to be, and then start making some reasonable estimates for tooth numbers.

No pinion should have less than 12 teeth to avoid under cutting when the tooth is being formed. Typically you do not want to go to tooth numbers a whole lot more than 100 as they are more expensive to make.