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Alternative to break motor

Alternative to break motor

Alternative to break motor

(OP)
I am using a standard motor and helical bevel gearbox in a lifting application. In order to prevent the load from back driving the gearbox when it stops I am using a break motor. It all works great. I am concerned about the life of the break motor. We are using a frequency drive to bring the load to a stop before engaging the break to eliminate break pad wear. We are using a 3HP break motor from leeson, and just looking at the mechanics of their break it does not look like it was designed to engage and disengage 500 times / day. I was at six flags riding the tony hawk ride and notices they were using sew eurodirves to stop the cars, but it just looked like a standard motor and parallel shaft gearbox. Would something like a vector motor / vector drive have the ability to hold the load? Or do you have any other suggestions?

RE: Alternative to break motor

I don't know of any motor (without a mechanical brake) that could hold the load when the motor/drive loses electrical power.  Have you though about a worm gear reducer?

RE: Alternative to break motor

(OP)
I am not worried about falling when loosing electrical power.  I am looking for something to hold it at the top.  A servo motor could do this, but that would be too costly for this application.  

RE: Alternative to break motor

Certainly a vector VFD would be able to do that.  That would actually be a great choice.  You may need some aux cooling if you do a lot of holding.

Keith Cress
kcress - http://www.flaminsystems.com

RE: Alternative to break motor

(OP)
Jraef,

That is what type of vector motor/drive I was referring to.  Is there a spec that shows how much torque I could expect at zero hz?  They say full torque at zero hz.  Is that really what they are capable of?

Thanks for the info.

RE: Alternative to break motor

Yes, they are really capable of it. But read all the info in the faqs and the above posts, as well as doing a Keyword search in here on "Hoist VFDs". There are caveats a-plenty.

Typically I don't recommend doing it for the novice VFD user, I would suggest getting someone involved who has specific experience in applying vector VFDs to hoists. A relatively minor error can result in a runaway load, something you likely want to avoid.

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