Mating Gear center distance more than standard 1

[benkhak]

hi, It's common to reduce the center distance of 2 mating gear in order to lessen the backlash of mating gear which for more precise motion transmission. BUT I've a heavy load(32 tone) gear box in my stock which mating gears has a center distance more than standard and it is something unusual, Of course it is not installation or manufacturing error, because I have the drawing of gears and chassis. SO Is there anybody here face to such a case.

 

[gearcutter]

There are two PCDs that are used in gear profile design.

There is the theoretical PCD which is used for calculations such as working out the pitch.
The theoretical PCD is often referred to as the 'standard' PCD from which the 'standard' mounting distance is calculated.

The other PCD is known as the 'operating' PCD (sometimes also called the generated PCD). The operating PCDs are the ones that are in contact when mating gears are run together.

Operating PCDs and standard PCDs are not always the same diameter.
Applying addendum corrections can cause the operating PCD to be different to the standard PCD and will therefore cause a change from the standard mounting distance.

It is not uncommon for this to be the case.
In fact; very rarely do I see gears meshing at the standard mounting distance.

Ron Volmershausen
Brunkerville Engineering
Newcastle Australia

http://www.aussieweb.com.au/email.aspx?id=1194181

 

[gearcutter]

Based on the data from your previous post;

Due to the plus addendum corrections applied to both pinion & gear; the operating PCDs are 305.277mm and 783.543mm.
This gives an operating mounting distance of 544.41mm, so the data you posted is correct.

Ron Volmershausen
Brunkerville Engineering
Newcastle Australia

http://www.aussieweb.com.au/email.aspx?id=1194181