What is Correction Factor in a Gear Profile?

The correction factor is the radial displacement of the tooth generating profile.

When + (toward exterior) the tooth becomes more resistant to bending and the curvature decreases so that also the contact stress is less.

A correction affects the distance between the shafts as well.

Many times corrections are made in order to have all over the tooth the same sliding direction.

For formula look in a book since it is not easy to give this way all the details which are many. To play with corrections if you do not understand the details can be dangerous.

A remark a + correction reduces the with at the toot end so that it can compromise its resilience in case of treatments for a better contact stress limit (case hardening).

Suggest a book to ensure the formula.

Or you itself, send me the same in pdf format as attachment

Dear Mr.tny,

Gears Design by Mr.MAITRI, available in pdf format and you can down load from the link. Search in Google and you can down load.

Pl. indicate your mail Id. thrugh the PERSONAL MESSAGING in CR4 and I shall send it to you.

DHAYANANDHAN.S

There are many aspects in which correction improves engagement. One of them is that diminish the minimum number of teeth, a very important matter in some applications, especially when space is critical.

Regards

Gabriel

you are of course right but this is one aspect it requires in order to avoid undercutting a + correction which will lead to a sharp tooth and limit the portance.

Dear Friend,

I suppose these details should help.

Gear correction:

We know that the most gears are made by milling,hobbing or tooth forming.In any case the idea is to generate the tooth form on the workpiece by replicating that on the cutter.Now when the cutter(profile generator) is moved away from the center of the workpiece, it gives rise to a profile stonger at the base and weaker at the tip.This is positive gear correction.Whereas when the cutter is moved towards the workpiece center it results in negative correction.Negative correction results in tooth undercutting thus reducing strength at the tooth base.

Where it is done:

Gear corerction is done where a chosen number of teeth and module, for gear and pinion, results in a center distance which is slightly <> the desired center distance between the two shafts.

Note:

Gear correciton can be done only for Involute tooth profiles only.It is not possile with cycloidal tooth profiles.

For calculations regarding these refer to Central Machine tool Institute's "Design Data Handbook"-Gear section.

Regards,

Pratheep Gunaseelan,Hyderabad,India.

Visit www.me-bac.com to calculate correction factor for spur gear.