Home Forums General Discussion Technical Questions Why use breaks on geared traction machines

A worm gear is a self locking one way gearing system it is always input turns output but output never turns input. With that being said why are there breaks on worm gear traction machines? If the motor isn't moving the shave isn't moving.

what goes up must come down, guess you've never done a full load test

sure pull the brake off and see what happens i bet you would change your mind.

After the car crashes into the overhead and then sets safeties the real fun begins

where are these people coming from.

We need to screen better.

And that people, is why you should only deal with certified elevator technitians.

I guess the fundamentals of elevators and law of gravity are too much to grasp for these rocket scientists

RCD

What kind of work do you do?

washing machine tech?

RCD there is always a reason for a design engineer to add a piece of machinery, always. This is why knowing fully how the mechanicals on a lift or escalator should be known by mechanics as it will lead to disasters like a lift rolling away from a floor. Your idea that a worm gear is a 1 way self locking system is totally false. The crown wheel and/or a worm gear of themselves are completely free to spin as they want, so they don't lock by themselves. Even the hoist motor doesn't have a brake by itself which is essentially why there is a brake drum attached. By connecting the motor output shaft to the input connection on the brake drum, and then the worm gear input shaft also to the brake drum connector this gives the worm gear the appearance of strength but it is still on a snap of the shaft away from running away. Im so glad you spoke up about this instead of testing your theory at the job site. Ask questions mate before you do anything!!

Wow!

Scary, just goes to show you don't know who you are following in this industry sometimes. I'm all for learning new things, but I wouldn't attempt brain surgery, not without the days course they run anyway! Lol

I'm wondering if this thread was originated by an office manager trying to cut cost?

Ahh the enthusiastic university student. Got to love 'em, they know so much and yet not enough to get it right. Have a university on service and the head whatever of the engineering department has a formula to determine when the drive will go bad within a week of his predicted date, date is written on the drive and I can't wait.

So everyone knows that a worm gear will not hold a load but no one seems to know why.

So your saying the worm gear will hold the car? Please explain.....Go prove it take the brake off a geared car around the 2nd landing and see if it works

I thought gravity was a clear enough reason. Oh, and add #10,000 lbs. in addition. Clear enough?

Every single one of us has been in the situation of an elevator "free-wheeling". Trust us, your theory is Crap.

Snap.