ball burnishing process on herringbone gear (newbie)

[JEK5019]

good day all -

you'll have to pardon me as i have '0' experience with machining. however, i am beginning some designs that i intend to manufacture - and need some help in clarifying. :unconscious:

i have created a herringbone gear. i would like to the finish to be highly polished - like ball burnishing.

what kind of machines will this require? a 4-axis for the herringbone?

i want the edges of the herringbone gear to be sharp (like the original design) will ball burnishing wear down the edges?

thanks in advance!

[magicniner]

It's worth reading up on machining processes, it will inform your questions.
You will need at least 4 axis for a herringbone gear, provided your machine is rigid your part will be as it is in CAD, you control the finish with the options in CAM.
"Polished" finishes are achievable with machining, the finish is a function of how fine the finishing pass is, the finer the cuts, the longer the time taken.

[JEK5019]

thanks again nick -

i wasn't aware that type of finish could be achieved with machining alone. i'll look more in depth on the machining processes. :rapture:


It's worth reading up on machining processes, it will inform your questions.
You will need at least 4 axis for a herringbone gear, provided your machine is rigid your part will be as it is in CAD, you control the finish with the options in CAM.
"Polished" finishes are achievable with machining, the finish is a function of how fine the finishing pass is, the finer the cuts, the longer the time taken.

[m_c]

If you've not already seen it, and odd gear designs interest you, you might want to check out Gearotic - http://www.gearotic.com/

It lets you design a plethora of gears, and can output the required code to machine them.

[JEK5019]

nice - thanks - this is a great resource!


If you've not already seen it, and odd gear designs interest you, you might want to check out Gearotic - http://www.gearotic.com/

It lets you design a plethora of gears, and can output the required code to machine them.

[JEK5019]

i designed the gear in fusion 360 - and i'm interested in figuring out how to sort the output code from withing the software.

silly question - but if i manage to create the output code from fusion 360 - is that code universal? or is it unique to both the software and thr machine of choice?


nice - thanks - this is a great resource!

[MartinS]

i have created a herringbone gear. i would like to the finish to be highly polished - like ball burnishing

I assume that you mean that you have created a design. Is this the gear that you created the first pic. and do you want it to actually run with a mating gear? It won't, there is no root clearance. Is the tooth flank shape based on an involute? (needed if it is to run)



what kind of machines will this require? a 4-axis for the herringbone?

Helical gear teeth are normally produced by shaping or hobbing. Although a double helical (herringbone) gear can be cut complete without a central groove for cutter pass through, they are generally assembled from one right and one left hand gear as the pump rotor gears in the second picture.

Knowing the geometry of the teeth in picture two, I cannot imagine that it (the complete gear) can be produced by milling. If it is not for running and you take a few liberties, then it might be possible.

In theory with a fourth axis, it should be possible to mill a single helical helical gear having a true involute flank and the correct root form.



i want the edges of the herringbone gear to be sharp (like the original design) will ball burnishing wear down the edges?

I recon that the corners will suffer rounding, but as Nick says "ask the supplier"



Hope you're not being put off.....

Martin

[magicniner]

I recon that the corners will suffer rounding, but as Nick says "ask the supplier"

Inside corners only.

But if you relieved the outside corners to a slightly larger radius there is no reason the gear wouldn't function perfectly, the "Point" and "Valley Bottom" on the gear where the two opposite angled tooth profiles join can be relieved significantly for clearance without affecting the function of the gear.

If you made a finishing pass for the inside corner with an engraving cutter you could actually get quite a sharp inside corner, you'd have to have good 4-axis CAM for that, and know how to use it too.