Rollers Instead of Spur Gears 1

[vbk]

Hello,

I'm attempting to design an all-plastic, low speed 2' dia rolling cylinder. This is a 1-of-a-kind & I want to drive it by way of roller pins instead of involute machining. I'm curious if anyone can shed light on how i should handle the tooth profile geometry. An example is Nexen group's product but i have a 6.5" pinion & a 28" roller gear. Any benefit to having the pins on the pinion as compared to on the gear?

Thanks, vbk

 

[MikeHalloran]

If you get the diameter right, your driven gear can be a simple disc with a roller chain wrapped around it.

You need also to either inlay a single tooth in the disc, or make the chain two pitches long, and engage the ends in a radial slot. Terminate the ends in a block that slides in the slot and is drawn inward to tension the chain.. or something like that.

Such a drive is to some extent abusive of the chain, and regular sprockets don't have the exact perfect geometry for it, but at low speed and low torque it may not matter.



Mike Halloran
Pembroke Pines, FL, USA

 

[vbk]

Thanks Mike,

Another detail that makes this tough is that I'm planning to have the potential to hinge this open so discrete plastic pins are more attractive. The speed will be ~2 rpm & the torque will be ~200 ft*lbs.

VBK

 

[JCJackson]

Buy off-the-shelf gears from such like as Boston (US)or Deval (UK)