Which is better to rotate an axis? Cylinder or Motor

[Gustavo Silvano]

Hello There!

I need to rotate an axis of 40 mm of diameter and 2500 mm of lenght. The range of the movement is of about 75º.
What I want to know is: is it better to use a cylinder or a motor to do this movement?

There's a picture below of the axis that I need to rotate, with the structure that it's attached.

Best regards

Gustavo

 

[MikeHalloran]

The picture is confusing.

Is there a slider-crank in there?



Mike Halloran
Pembroke Pines, FL, USA

 

[BEMPE16524]

How is your mechanism? do you want to rotate both axis independently?
If yes, you may need individual motor or cylinder for each axis.
Otherwise, you can use single motor or cylinder.

 

[tygerdawg]

Range of motion, whether stop-to-stop or continuously variable, speed of motion, precision of motion, mass of load...all of these are needed to fully specify a solution. Options could be a pneumatic cylinder with crank-arm arrangement, a big-honkin' pneumatic rotary actuator, same with hydraulic power, electric gearmotors, or a motor+chain or motor+belt arrangement, or motor driven linear actuators.

TygerDawg
Blue Technik LLC
Virtuoso Robotics Engineering

http://www.bluetechnik.com

 

[Gustavo Silvano]

Sorry for the picture, I'm uploading another one, which I think will explain better my problem.
It's a simple project, that I can use a cylinder or a motor to make the movement. But I'm concerned about issues like maintenance, durability, cost and reliability.
Which one is better to apply in a general scenario, a cylinder or a motor to do the movement?

 

[dhengr]

Gustavo Silvano:
For goodness sakes, you have CAD to do your drawings, so you don’t have to know how to do any drafting, but you should know what you want to show or need to show. If you can’t describe your engineering problem in engineering terms so other engineers can understand what you are trying to do, you probably shouldn’t be doing this problem without some serious supervision from your superiors. Is that moveable fin/gate 6" long or 60' long; 3" high or 10' high? Does it weight 10 tons or 1 pound? What is it holding back, 62.4lbs./cu.ft. or something else; what forces are acting on it? Is it under water or in some other medium? Tell us how it works and why. Don’t show how the motor is oriented, when you don’t know if it should be a motor. You need to provide the info. needed to understand the system and the problem, and all the info. needed to solve the problem, we can’t see it from here.

 

[BrianE22]

If it needs to be held in place you would need the motor to have a brake. A cylinder would hold it (for awhile, until it leaks air or oil).

Cylinders would need to produce a large force if the stroke is large and the moment arm gets smaller. You need to look at the forces and strokes for a cylinder and compare to the needed motor torque.

Do you need precise positioning or just stopping points? Precise positioning might require feedback for both a motor or cylinder. Real cheap would be an air cylinder and limit switch/valves.

Cylinders leak. Motors don't need much maintenance.

A motor would require a coupling and alignment with the rotating shaft. Cylinders just need rod end bearings.

 

[Gustavo Silvano]

Great, BrianE22.

I just needed some advice concerned about cylinder and motor, and you just gave me that.

With your post I decided to use a cylinder, once the precision is not required and is much cheaper

Thank you.