## Gear Pinion outside diameter calculation

## Gear Pinion outside diameter calculation

(OP)

Hello,

I need to make 3 new helical gear pinions with the same type of teeth of the attached picture (sample gears)

How can I calculate the outside diameter D for each of the new pinions. Z1=20 , Z2=22 and Z3=24

I have measured the outside diameter of the 2 sample gears:

Z=40 , outside diameter= 173,5 mm

Z=25 , outside diameter= 111 mm

I need to make 3 new helical gear pinions with the same type of teeth of the attached picture (sample gears)

How can I calculate the outside diameter D for each of the new pinions. Z1=20 , Z2=22 and Z3=24

I have measured the outside diameter of the 2 sample gears:

Z=40 , outside diameter= 173,5 mm

Z=25 , outside diameter= 111 mm

## RE: Gear Pinion outside diameter calculation

## RE: Gear Pinion outside diameter calculation

## RE: Gear Pinion outside diameter calculation

How did you came up with those numbers?

## RE: Gear Pinion outside diameter calculation

## RE: Gear Pinion outside diameter calculation

## RE: Gear Pinion outside diameter calculation

## RE: Gear Pinion outside diameter calculation

I also drawn the shape of the teeth. See attached file

## RE: Gear Pinion outside diameter calculation

## RE: Gear Pinion outside diameter calculation

The gear thickness is 40mm. They are from a very old wire drawing machine (around 1950s) and yes I need new pinions and I dont have any other information about the gears except those samples which are originals

Could you explain what is a "profile shifted gear"?

As you said: The goal is to correctly identify the gears and manufacture a set of good replacement. I know that probably the best approach should be to send the gears to a gear shop and ask them to manufacture the pinions accordingly by just telling the number of teeth that I need but there are no good gear shops around here and I personally dont trust them at all

## RE: Gear Pinion outside diameter calculation

By "profile shifted gears" I mean gears with addendum modifications.

Let us know how we can help you further.

## RE: Gear Pinion outside diameter calculation

We are starting to machine the gears today. Material is steel grade SAE 8620 and they will be case hardened after they are finished

I am using Occupant`s diameters