Rotational Torque Calculation

[hungrydinosaur]

Hi All,

I am designing a winch, which would have a drum weight of 2000 kg, and wire rope of around 4500 kg wrapped on the drum. I need to find the torque required to rotate the drum from rest.
Is there any literature or reference I can refer/read to? Thanks in advance.

Regards,

HD

 

[LittleInch]

For others - I advised him to try this forum, but see my initial guess at this topic either here

http://www.eng-tips.com/viewthread.cfm?qid=372689

or

There's plenty, but you need to go looking yourself.

The key aspects for a free rotation are the static friction from your bearings and the force required to accelerate your rotational mass from zero up to your desired speed.

Then you need to add in frictional drag on the rope / cable if its being dragged along the ground and finally factor in the maximum pull force on the rope. As this is a winch I would have suspected that the latter would be head and shoulders over the others, but I don't know your duty.

Look up rotational inertia and how to calculate the effective diameter of your total mass to determine your torque which is then force = mass x rotational acceleration

You might have had more luck in the mech eng other topics forum - things like this come up there more frequently than in the pipelines one(!)



My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[drawoh]

hungrydinosaur,

A 2000kg winch with 4500kg of cable plus some appropriate load sounds like a job for someone who knows what they are doing. At the very least, there should be someone looking over your shoulder who knows what they are doing. How catastrophic will it be if this thing fails?

You are asking questions about second semester mechanics. There is all sorts of more advanced level structural analysis you absolutely must get right. There are all sorts of handbooks that contain the equations you need to work out friction and inertia. What are you using for bearings? What are the bearings sitting on? How is the wire rope attached to the drum? Who is standing underneath all this stuff while it operates?

I would not want to touch this thing unless I could work with a designer experienced in this stuff. It is not just the analysis. It is all the practical stuff. What hardware do they approve of. What regulations have to be followed?


--
JHG