Separating gears

[oogabubchub]

I'm designing a machine for my boss and one of the necessary elements is to have gear driven shafts/rollers that can separate up to a distance of 1/2". The gears will have a diameter of approximately 2" and need to be able to move while meshed together at all distances from 0" to 1/2" apart.

If you notice in the attached photo, gear B needs to be able to move down 1/2". All these gears will be driven by one motor (the motor can drive either gear A or B).

Is this possible? I'm concerned that the separation of gears will cause it to not function properly. Chatter during normal operation is unacceptable (though, an initial impact due to the gear teeth closing any distance caused by separation is acceptable as long as rotation is smooth after that). Any other ideas on how to get around this? Thanks.

 

[oogabubchub]

Not sure if the image worked but here it is again:

 

[PeterCharles]

I think I would -

1) drive A from C as meshing gears

2) drive B from A with an overlong chain drive

3) tension the chain between A and B with a spring loaded jockey pinion to take up the slack in the chain.

This will allow B to move the 0.5" you want.

 

[Compositepro]

This is commonly done with nip rolls. You introduce two gears between A and B. The four gears can stay in constant mesh while A and B move apart. It can also be done with chain and sprocket.

 

[dvd]

Depending on torque transmitted, and arrangement, these may help:

http://www.tolomatic.com/products/product_detail.cfm?tree_id=141&category=gearboxes-gear-boxes