AEG gears and balancing...

[Egon_247]

Apologies for the random questions but I do tend to over think stuff...?

Ok, so a standard AEG with standard motor. 18,000 rpm motor through the gears makes the sector gear do 1000 rpm. Not that you're holding it for a full 60 seconds but that's rapid, isn't it? 

Now, the bevel and spur gears are fine as they're concen concen con, round. They're balanced while spinning.

The sector gear has big pointy lumps sticking out of it to do it's piston slinging magic.

It has holes drilled in it too, I've noticed. I'm sure they balance up fine. 

But what about when you short stroke one? Two, three, four teeth missing on something that rattles around at 1000 rpm, even momentarily is surely going to cause some "ann summers" type of chaos in that little ally gearbox?

Is there a way of balancing them? 

I've tried to do it by using a countersink on the opposing drillings and resting the shafts on a cut out slot, but is this a thing? 

Or am I overthinking it and need more ssri tablets? ??

 

[Iceni]

It makes no difference.

The only gear that isn't balanced is the sector gear, but the sector gear is arrested and under load from the piston/spring  and spur for 50% for the time. So you will see more load wobble from that than you will from gear imbalance.

SS 2 teeth and you can't even feel any speed wobble over the rest of the gearbox working. Bearings get crushed/fail because of the spring and the load that puts through the bearing, not because the gears are resonating.

Basically slap yourself round the face.

 

[Egon_247]

Basically slap yourself round the face.

Agreed. More drugs applied.

??

 

[Leo Greer]

The closest thing I can think of to what you're describing would be caused by, as Iceni says, the spring. This can be related to a bad, soft spring that's bending out of shape (looking at you, SHS), a piston that's the wrong spec for your gearbox, or a few other reasons.

 

[Pseudotectonic]

There is the piston going back and forth making whatever vibration from the gears pretty much meaningless, assuming that is your concern

There is not much mechanical difference in terms of the force being applied on the bearings or bushings because the majority of that force is from the transferring of power from the motor to the piston pulling back a spring, your gear doing a little shake is going to be a negligible in comparison

 

[Egon_247]

I'm not getting any vibration per se, I just wondered if it would cause issues. 

I mean, I'm amazed my ex wife hadn't knocked all her fillings out with her stuff....?