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!

*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.

Jobs

flat strip spring in wave format for drag spring in annulus.

flat strip spring in wave format for drag spring in annulus.

(OP)
I am looking for design info for an annulus spring to act as a friction drag between the inner and outer shell. Radius is 21mm, torque wanted is 0.7 N-m initially.
width is 3.5 mm , annulus height is 2mm.
By initial fit estimates cof as 0.05, grease packed. Net force = 700 N, drag force = 35 N.
by dividing into wave-to-wave pitch, 1mm compression, 60 degrees pitch, I get thickness
of 0.5mm, using the leaf spring formula, L = 1/4 pitch (cantilever)
I now have to deal with end conditions.

I estimate circumferential expansion as around 5 %
3 "points" of the leaf springs are missing or ineffective, and the outer "points"
have one long arm and one short arm, plus transfer some end effects further into the spring.
1) What pitch and number of points do I need to restore the net force to 700 N ?
I could crowd the end points closer together to compensate for end effects.
non-centered thrust is not a problem.
2) What surface speed can I run up to, assuming bearing grade and finish rings, spring grade
steel for the "flat" spring.-probably simple carbon steel, grease packed.
The intended rpm is about 60 rpm at present.
The application is a "packaged" self-activating spooling clutch, as opposed to a one-way bearing.

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


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close