Force to rotate 100 ton cylinder suspended on Rooler Brg

[websail7]

I have a 100 ton concrete cylinder 130" in dia x 230" in HT
This obj is suspended on a Torrington Roller Thrust Brg. How would one calculate the force req'd to overcome the bearing friction and cylinder inertia?

 

[GregLocock]

You need your first year mechanics book, the rolling resistance of the thrust bearing, and the moment of inertia of the cylinder.

It'll be a torque, not a force, at rough guess.

Cheers

Greg Locock

 

[israelkk]

GregLocock

I believe the moment of inertia is not needed. Just the starting bearing coefficient of friction, the "mean diameter" of the bearing (where the rollers are located) and the cylinder weight are needed to calculate the atarting torque.

The starting torque to rotate the cylindser is

T=100*mu*D/2

Where

D - the "mean diameter" of the bearing
T - Torque
mu - starting bearing coefficient of friction (the running coefficient of friction will be lower)

The moment of inertia is only needed if you want to calculate the acceleration and torque to achieve angular velocity in a specifed time.

 

[GregLocock]

You're right.



Cheers

Greg Locock

 

[JStephen]

The question asked about overcoming cylinder inertia, which implies an acceleration.

 

[GregLocock]

israelkk is still right, he just didn't read all of the question!

Cheers

Greg Locock