×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Torque calculations for axial loading.

Torque calculations for axial loading.

Torque calculations for axial loading.

(OP)
Hi guys,
How do you calculate the torque required to turn an axial load on the shaft. For example, the shaft is in a vertical position and a weight of 100lbs placed on top of the shaft, how would you calculate the minimum torque for the shaft to rotate?

RE: Torque calculations for axial loading.

Use f= m * aa, if you ignore friction.

Ted

RE: Torque calculations for axial loading.

Depends on how much angular acceleration you want, how much friction must be overcome, and the moment of inertia of the entire rotating mass. All must be quantified to calculate the torque.

RE: Torque calculations for axial loading.

the general equation (for tightening a screw thread) is T = F*d*k. k = 0.2 is generally used to account for friction, thread ramp, etc.

but your question seems to be a little different ... a shaft with a mass sitting on top. how does the shaft interface with the rest of the world ? a flat surface ?? so the torque is over-coming the friction of the face-to-face contact ? or is the shaft threaded into the base-plate, and you're trying to lift it (against the load) ?

nothing to do with F = m*a, IMHO

another day in paradise, or is paradise one day closer ?

RE: Torque calculations for axial loading.

fakeringing, search for power screw solutions.

Ted

RE: Torque calculations for axial loading.

Simple.
Torque = [mass moment of inertia] x [angular acceleration of the assembly]

MMI can be manually calculated using standard MMI primitive formulas found in 1000's of places or developed from your solid model CAD program.
angular acceleration ~ [change in velocity] / [change in time to achieve that velocity]

Upsize it for friction, etc.

Websearch the Smart Motion Cheat Sheet in pdf format, it has the formulas you need.

TygerDawg
Blue Technik LLC
Virtuoso Robotics Engineering
www.bluetechnik.com

RE: Torque calculations for axial loading.

What is supporting the shaft and how is the shaft held in a vertical position? Also what mechanism is involved in turning the shaft?

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources