Mechanical Engineering

Geneva mechanism?

It will be more comprehensive if you attach some sketches or illustrations what are you going to achieve.

Seems really like Geneva mechanism, as Bob said. And try to select the proper electric motor with control hardware.

Hi

in my opinion I would take a Brushless motor

with a position sensor on the shaft and a bit

of software to solve this.

How much torque you need?

BR

Gerhard

A step motor could be the solution.

Do you want to use commercial off the shelf parts? Are you capable of developing electronic hardware and programming for a stepper or servo? Do you want to do it with a purely mechanical device?

What are your constraints?

Thank you for all the help! I would like to use a strictly mechanical system driven off the machine's crankshaft. The torque required to rotate the shaft is 20 ft-lb. The profile is a sine wave, 0 ft-lb at 0 degrees, 20 ft-lb at 45 degrees and back to zero at 90 degrees. I was thinking a Geneva system if I can get the speed right?

Hello!

The idea shown in this video seems interesting not so much because it obtains discontinuous turns (which the Geneva mechanism and others also provide) but because its permanent contact could protect it from impacts and premature wear.

Indexing Non-circular gears Mechanism Device - YouTube

I once worked on a fast machine (for the food industry) that had a large diameter station that had to rotate 90 degrees every 1 second. I remember that, in the conceptual stage, I proposed to them to review some alternatives for movement generation, from the safest and most sophisticated, to the most elementary and susceptible to wear and positioning problems.

I share one image:

you said: driven by crankshaft, is it on a combustion engine?

Hi:

Thank you for that. I actually built a prototype of this machine which worked. I rotated the shaft with a pneumatic cylinder and a short lever. It was noisy and hard to precisely control the rotation. I tried to find a rotational or linear actuator to do it with but ran into problems with speed and load. I could do it this way but it takes about a 5 hp motor. I only have power enough for a 1/2 hp. I was hoping to drive the Geneva system directly off the machines crank.

Yes, more or less,

The position sensor can help any motor but preferably an electric motor.

????