×
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

Hirth Coupling only for positioning

Hirth Coupling only for positioning

Hirth Coupling only for positioning

(OP)
Hi
I would like to have angular positioning of a lever with a Hirth couplung. Is it posible to design a couplung with one side of the tooth perpendicular (0° angle) and the other side normal (30°)? How difficult is to maschine such piece.

The problem:
I would like to have the rotation of the lever fixed only in one direction (see attachment). For the axial force I want to use just a simple spring because the lever angular position will be positioned by hand. The maximal torque is estimated to 200Nm.

The problem with a standard Hirth gear is that the tooth's angle is to large which requiers large axial force.

Any other suggestions how to design a mechanism for the same job.
Thnx

RE: Hirth Coupling only for positioning

The difficulty of machining such a part depends on tiny details like tooth root configuration, tolerances, material, and finish, none of which you have hinted at in your sketch. Go talk to a machinist.

First, eliminate the possibility that you can't use a semi- standard stock machine tool part from a place like Carr-Lane or Reid's.

Mike Halloran
Pembroke Pines, FL, USA

RE: Hirth Coupling only for positioning

(OP)
The main function of the gear is to sustain a static loading of 200Nm with minimal axial force (spring). The accuracy is not much that important. The lever just needs to be adjusted to best fit the ergonomy of the operator.
What kind of tolerances (if the outer ring diameter of the gear is 50mm) would you suggest? Where can I find this tolerances?

Thnx

RE: Hirth Coupling only for positioning

End mills can be obtained with various angles: (http://www.mcmaster.com/#tapered-end-mills/=ijeuiu).

With enough room between teeth you could use a square end mill on one side of the tooth and a tapered end mill on the other side of the tooth. It wouldn't be tough at all to do with a CNC mill. If the teeth are hardened it might be a bit expensive if grinding is required.

RE: Hirth Coupling only for positioning

You might want to look at using this type wrench to accomplish the task. I've used the on many different applications. The can be locked with the proper design. I believe that you can get 72 teeth models which will give you some precise positioning
They are all of fthe shelf items

RE: Hirth Coupling only for positioning

(OP)
Ok. Let's forget about the Hirth coupling. The positioning can be also done continuously. I'm thinking about a roller clutch whit a release button, to bring it back to start (I can't push it around).
Is anything like that available on the market? How is it called?

RE: Hirth Coupling only for positioning

(OP)
One more thing about Hirth joint....what kind of shaft dimension is normally used? What's the main reason for not having it 90° (no 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