QUICK LOCKING SHAFT MECHANISM

[diasmanuel]

Hi all,

I need help. I need to design a machine for testing electrical motors.
The problem is how to attach a motor that has a round shaft to the tester Machine, and in between there is coupling to compensate alignment errors ?

A collet sistem can not be installed because there is no hole on the main Arbor that could be used for feeding air or oil.

I tried a sprag clutch bearing .It works but it needs a hammer to unlock the system and that could damage the either the motor or machine bearings.

Any ideas ?



MD

 

[ScottyUK]

Something like a half-coupling equipped with a Fenner Taperlock bush for the motor shaft, and the opther half of the coupling being whatever fitting best suits you?


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If we learn from our mistakes I'm getting a great education!

 

[diasmanuel]

Thanks for you quick answer.

Yes, it works but i need to insert and remove the motors from the test machine at very hight rate aprox. each 15 seconds. The taper lock takes much time to install and to remove. I know that theres is a hydraulic bushing that uses a screw to increase the pressure in a chamber but i still have the problem of driving it. My system has to rotate so i can´t have a permanent conecction.

http://www.etp.se/index.php?id=106

MD

 

[BobM3]

Not cheap but hard to beat: the air powered collet closing mechanisms that lathes use. You don't need air through your shaft - an air slip ring coupling brings it in.

 

[diasmanuel]

The air powered collet you describe it´s to heavy and big for this aplication but the slip ring coupling sounds good. Do you know any supllier? As i´ve already mentioned before there are hydraulic bushings that are operated with a screws, so if i could connect a hydraulic tube instead,this would be perfect . Do you know any radial coupling , like a slip ring for hydraulic fluids ?


MD

 

[NomLaser]

What shaft size, torque and speed are these motors running at when you are testing them?

 

[diasmanuel]

Shaft size 15.00 mm, torque 10 Nm , speed 1000 r.p.m

 

[williedawg]

Not sure how much room there is, or what the main Arbor looks like, but maybe something aong these lines ?

http://www.workholding.com/atscatalog07.html

 

[MikeHalloran]

So long as the shaft is flatted or keyed, an adaptation of the Gator-Grip socket would probably be faster than anything else:

http://www.endeavorproducts.com/

Mike Halloran
Pembroke Pines, FL, USA

 

[BobM3]

Do a google search on "pneumatic rotary couplings" or "hydraulic rotary couplings". Often times, due to space constraints, you are forced to build your own. No big deal though - just seals and bearings.

Are you hoping to replace the coupling? Make sure if you do that you either have the driving and driven shafts lined up extremely well or have something compliant between the shafts.

 

[NomLaser]

Can you describe your setup a bit? Are you driving a dyno with them? Do you have to swap out the entire motor in 15 seconds? Are there any pilots on the motor for a mounting plate or similar? Is the shaft keyed? Does this need to be a blind connection? Blind connections can really limit your choices on connections. I have used Hayes couplings in the past and the Hex-Flx couplings have excellent wear resistance and good misalignment fits.

FYI

http://www.hayescouplings.com/index.php/products/hexflx_couplings

 

[diasmanuel]

BobM3

I did search on rotary coupling but i didn´t find anything.
As i can´t have a hole through the main shaft/arbor i need to feed radially.
I must have a coupling between the driven and driving shafts.

NomLaser,

Yes i´m driving dyno. Yes i have to test motor perfomance as fast as possible because this is for motor mass production. The shaft is not keyed and the motor is clamped on a flange.

Currently i´m using a coupling from Zeromax that has a collar incorporated so drive the screw to make the connection between the shafts.

I think that i can build a spline coupling that is attached to the shaft before i insert the motor to the tester, this can be a solution. Takes to much time but....


Thanks for your inputs.

 

[tygerdawg]

I designed a gearbox test rig once that required fast connect a single motor to multiple gearbox shafts. They wanted to connect the motor to the load so they could do gearbox functional tests quickly. I specified a "tapered polygon coupling" for connect speed, torque handling capability. A male coupling half was permanently moutned to the motor, and a female coupling half was designed to slip over the keyed shaft easily for quick attach. Similar to

http://www.generalpolygon.com/index.htm

There are others out there to be found on the net.

Customer very much liked the idea for ease-of-connect, speed-of-connect, torque handling capacity, mis-alignment ability. But they had many many shaft types on many many gearboxes, so the cost of providing a separate coupling for all the different shaft sizes was prohibitive.

TygerDawg
Blue Technik LLC
Virtuoso Robotics Engineering

http://www.bluetechnik.com

 

[diasmanuel]

The driven shaft i want to connect it´s not keyed.

Thanks.

 

[BobM3]

For hydraulic rotary couplings:

http://www.deublin.com/

 

[MintJulep]

Why connect it at all?

Put a suitable friction "tire" on your dyno. Press the shaft up against that. Add a backing wheel to keep the radial loads on the bearings to an acceptable level.

 

[waross]

I was thinking the same, but you beat me to it, MintJulep. An air cylinder loading the back-up wheel should allow very fast connecting and disconnecting.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[unclesyd]

I would use something like a bottle capping clutch or similar device.
Here is just one of many out there.

http://www.rimteccorporation.com/products/magnetic/hsvbc_series.htm

 

[MikeHalloran]

The sprag clutch works; just add a manually operated rotary hammer to the spindle for releasing it.



Mike Halloran
Pembroke Pines, FL, USA

 

[BobM3]

The "tire" is a neat idea. I recently saw these in an ad:

http://ruland.com/ps_collars_shaft_qcl.asp.

One by itself wouldn't be able to react your torque in friction but maybe you could use the idea.