Eccentric axle

[ibieng]

Hi guyz,

Can someone help me with the calculations for a motor on an eccentric axle. In the attachments I attached information and a picture about it the situation. I have been trying to calculate the torque and power, but I can't find an formula or an example on the internet. I hope you guys can help me.

Thank you!

 

[handleman]

I believe what you have here is an example of the rarely encountered mechanism known as a "cam".

 

[MikeHalloran]

The blue roller looks like an idler, not a driver, given a bearing-ish thing inside.
I am having difficulty understanding what rotates what, and what moves relative to what.



Mike Halloran
Stratford, CT, USA

 

[GregLocock]

As drawn, making the usual spherical cow assumptions, it needs zero power on average, assuming the cam is sprung against the blue drive wheel. That is because there is no net work being done.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[handleman]

I believe the blue thing is the follower, which is pushing downward on the cam with 50kN in the sketch. It sorta looks eccentric, but I'm pretty sure that's due to distortion at the edge of the wide-ish angle photo. The cam itself looks like it's clamped on the shaft being driven by the timing belt.

 

[BUGGAR]

I suggest that the eccentric blue wheel rotates to bear against the aluminum clamp holding the bearing that holds the timing belt, to tighten the belt. The blue wheel is locked in place by its center bolt when the chain is tight.
In thinking about this, if your geometry was right, it could be a self tightening mechanism if you put a rotary spring in the blue wheel.

 

[ibieng]

Well thanks for your reactions, but I can see now that it might not be so clear. Handleman's description is right "I believe the blue thing is the follower, which is pushing downward on the cam with 50kN in the sketch. It sorta looks eccentric, but I'm pretty sure that's due to distortion at the edge of the wide-ish angle photo. The cam itself looks like it's clamped on the shaft being driven by the timing belt." Yeah I was searching on the internet and the only example that looked like my situation is a cam. In the calculation examples the cam has an oval form, so I questioned myself wether I can use it or not. Still I couldn't find a way to calculate the motor torque. the motor is connected to a roller where the eccentric cam is fastened on. I also posted a beter picture.

The purpose of the eccentric axle is to push the blue idler up. In the new posted pictue you can see two of them on one conveyer roller. The purpose of the device is to transport a package 90 degree away from the roller conveyer. This device is fastened under a roller conveyer.

I hope its more clear now guys.

 

[MintJulep]

It's a cam.

Formulas are in every design of mechanisms book ever written.

 

[BUGGAR]

Never mind the mechanism, work on the communication.