×
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

Worm Gearbox

Worm Gearbox

Worm Gearbox

(OP)
I'm in need of compact gearbox and the only thing I can come up with is a worm gear type.  I don't have any experience with this type of gearbox so I was looking for suppliers and gear cost and began to notice that the worms would have a description of RH on them.  Now I'm begining to think that worm gears are directional.  My question is are they directional?

TIA
Erik

RE: Worm Gearbox

RH would be Right Hand (like most screw fasteners).  It just determines the direction the gear rotates when the worm is turned in one direction.  The teeth on the gear would have to match the "handedness" of the thread on the worm.

RE: Worm Gearbox

Some worms and helical gears can be directional, the classic automotive differential gears being a common example.

The teeth are often not cut symmetrically for very high torque applications.  The pressure face will be nearly vertical, and the trailing side of the tooth will be cut at a steeply sloping angle for clearance to the next passing tooth.

This may or may not be relevant to a particular gearbox, but for the higher torque rated gearboxes it is not uncommon.

RE: Worm Gearbox

Try looking at this website to answer some quetions on what you are defining as crossed axis helical gears

www.webgearservices.com

RE: Worm Gearbox

(OP)
Thanks for the info everyone.

Here's my next question...can the worm be driven with the worm gear?  The worm would have no load.  Basically free-wheeling.

RE: Worm Gearbox

It can if it is not self-locking.  If the lead angle on the worm is below a certain value (theta < invtan (friction coeff)) then it won't backdrive.

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