I'm trying to find if there is such a coupling as a flrxible split coupling hub.
The application is a 10' diameter fan driven by a 350 HP motor through a single reduction gearbox. Running speed of motor is 1500 RPM and GBX is 600 RPM. This is a variable speed drive but speed but speed only varies +/- 10 RPM.
I am trying to find a coupling easy to remove when we replace brgs. What we have now is a shrink fit making the job much harder than it has to be.
Thanks for the help.
dnk

A solution on some of our fans is: Split bearings.

Many years ago while at Kodak: we had an old Millwright that would hand fit each coupling. The coupling may come with an interference fit but it ended up with a slip fit and of course engineering never knew. I never knew of a failure from those machines either. I've seen people shrink from 3 to 9 mils with a key. What holds the hub? The key or the shrink fit? I think the keysize is designed with shear in mind from design parameters and a full key should hold.

Regardless, the split bearing make the job easier and the back bearing as easy as the front. I do believe split bearings of today have greatly improved and their life expectancy is more 'normal' or you can get years service.

Sam is right about a split bearing. The only thing is they come with a "built-in defect" frequency because of the split races.

Another option might be to use water cooled split babbitt type sleeve bearing. They run quite well. I have seen them on center hung and over hung fans with speed ranges from 200 to 1800 rpm. Make them even better with a recirculating oil system.

I don't particular like to use the rubber tire type coupling, but it might be an option also. They come with an easy to remove "squeeze to the shaft" adapter.

T. B. Woods makes a type c Sureflex coupling that has a clamping hub that is partly split, allowing for a loose fit and tightening by with the clamping hub bolts. You didn't say whether you were looking for a high or low speed coupling, but you are at the edge as far as the torque transmission. Depending on operating conditions you may need to use the Hytrel sleeve, but be careful with the selection if that is the case. Hytrel sleeves are very torsionally stiff and can destruct very quickly under the right (or wrong) circumstances.

Anytime I see drive components being altered to accomodate frequent changes of some worn out element, I have to ask why you need to make changes so often?

Helped install and align a large "clutch" coupling (first I'd ever seen) the other day that used the split, tapered bushings that Danny mentions. This is basically the same arrangement used on sheaves; the bushing and hub are both tapered. Fairly easy to get on, and if you have enough clearance between the ends of the shafts, you could change the coupling without moving the motor (if you needed to do that).

One thing to keep in mind, with any tapered bushing (sheave or coupling) you have to indicate the face of the coupling to make sure it pulls up square. There is no guarantee the hub will mount square as there is with a shrink fit hub (assuming it is bored true, of course).

Warning: I work for SKF, so my opinions may be biased

Look at the "SH" Bushings made by SKF. They will clamp to the shaft absolutely square and do not require a keyway. They are easy to install and remove and sizes available to six inches. These bushings can be installed inside a common coupling hub.

http://www.skftransmission.com/SKF.nsf/(SiteIndex)/Mechanical_friction_joints

Thanks for the help. The reason for frequrnt replacement is an undersized shaft. We can't solve this problem until management decides to spend the money for shaft replacement. With predictive maintenance we have little downtime because we schedule replacement on downday. With cooper split brgs we have problems with inner race shifting because of tight tolerance.
Was thinking a tapered sleeve brg would grip shaft better. If we replace shaft problem wii go away.
dnk

The type of coupling I am referring to does not use the QD bushing like Rusty mentioned. It has an axial split in the hub portion that allows clamping using two bolts on either side of the hub.

http://www.tbwoods.com/products.php?level=5&GID=21&PID=6&MID=1

If you download the Flexible Couplings Catalog, you can find it on page F1-17