Forging gear

[Viet_Doan]

Hi everyone i want to ask a question about gear forging gear
i don't really understand what function it is (red mark ).it is for strengthen gear or something else, isn't it ?

 

[mfgenggear]

OP
Depending on the material, a forged gear with have higher UT and YT because of grain flow. Than wrought steel, eg bar , plate.

 

[EdStainless]

The shape is a tradeoff.
You want to use less material to save weight and cost.
But you need some level of stiffness and strength.

 

[Viet_Doan]

Well thank you so much
if purpose is to reduce cost, is it possible to remove them ? we have some gears with equivalent function but no this rib

The shape is a tradeoff.
You want to use less material to save weight and cost.
But you need some level of stiffness and strength.

 

[Viet_Doan]

OP
Depending on the material, a forged gear with have higher UT and YT because of grain flow. Than wrought steel, eg bar , plate.

thank you so much for explanation.
Is possible to remove these rib? I think we have to face some trouble with strength or manufacturing.

 

[mfgenggear]

OP
Even if it is forged, it still requires extensive machining , heat treating and inspection. Machining gears can be complex. Pull the process planing and all the certs.

 

[EdStainless]

Unless you know all of the thermo-mechanical history and properties of the gears I would not be modifying them.

 

[lucky-guesser]

The gears may mate up to other gears the same, but other thicknesses/geometry could be different to where company A need the rib for strength but company B can get away without it. Metallurgy could also be different. If you would of to try modifying one, I would do extensive testing before moving that to final production.

 

[3DDave]

The rib may be required to tune the vibration response of the gearbox/system.

 

[mfgenggear]

Gear rim , in this case rib is added for extra strength for the gear. Thickness of the rim and rib can not enough can result in abnormal vibration and wear to the gear. And the gear box assembly

 

[GregLocock]

A vague possibility (I have never designed a gearbox) is an oil thrower?

 

[mfgenggear]

Yes it can be, there many factors, torsional stress, resulting from high torque and rpm, shock, and moment to the box. Like a helicopter gear box.
Or gear box connected to a turbo prop, turbine generator, with extreme torque and rpm.

 

[MC6]

Sorry to open this back up, but this looks like to me a sintered gear? And instead it looks like the concave area outside the diameter of the rib was to reduce the total surface area needing to be ground flat. That inner rib yes would be for strength and stiffness comparative to the concave area, but I'm not sure if that radius is adequate? Given the lack of relevant information, that's an impossible question to answer.

Instead I'm mostly posting to see if anyone can point me to material/references on stress risers for axial faces like in this case, because I realized I don't have any.