Kubota Z482 crankshaft side load

[TheRadBaron]

This is my first post here.  Thanks for having me.  I'm a lifelong mechanic, tinkerer, and fabricator but I'm new to small industrial engines. 

I just picked up a nice '95 Z482-E engine out of a semi truck APU.  I'm planning to use it to build a belt driven 5kw generator.  I know the ideal plan would be to use a bearing supported stub shaft but my budget for this project doesn't really allow that, and I don't have the time available to fabricate one from scratch. 

Looking around at various parts diagrams it looks like there are a number of Kubota tractors and other small equipment with the Z482 that drives the main power take off from a pulley attached to the flywheel.  Same with other applications like Carrier reefers. From what I can tell most of these use simple V-belts. This tells me that these engines are designed to tolerate at least some side load on the crank.  I haven't been able to find any info, though. 

I'm thinking that I'd like to attach a ribbed belt pulley directly to the flywheel and use that to spin the generator.  I understand that ribbed belts don't need a great deal of tension to work properly so this seems to me like it might work.  I'd rather not sacrifice longevity of the motor. 

What do you guys think?

[Henry W]

A double AX belt setup would work fine.

A k belt (serpentine belt) requires more tension than a double AX belt setup.

There are stubshafts available for the Z482.

When installing a pulley on the stubshaft, get the pulley a close to the flywheel as possible.

[keith71]

How thick is your flywheel that you can let a 5or6 rib belt ride on it? My kubota D722 has a flywheel that is i inch thick including the ring gear. So I am left with about 5/8'' left for belt width. Probably not going to for me.. I bought a stubshaft for a D722 from a marine generator manufacturer. 1.125 shaft 2.875 long with a 5 bolt flange that fits into the flywheel.. They told me side loading is not an issue with these engines being dual belt driven. Keep tension reasonable.
Some pics of just trying to design a simple frame setup. Mocking it up for now. Probably more than a few changes needed.

[keith71]

One more pic.. Cigarette not part of build..  Quit 7 years ago.. It fell out of a box of parts and i did not see it when I took the pic and posted it here.. Sorry bout that.

[TheRadBaron]

Thanks for the replies.  That's interesting about the AX belt setup needing less tension than the ribbed "serpentine" style.  I always thought it was the other way around but I guess I got mixed up. 

My flywheel looks the same as yours, keith.  I didn't mean that I'd run the belt directly on the actual flywheel itself, just that I was going to try to mount the pulley directly to the face of the flywheel rather than using a stub shaft or other means of coupling that would move the pulley away from the face of the flywheel.  I'd like to keep the pulley directly on the face to minimize the leverage effect and increased side load force. 

I'm glad to hear that a reasonable side load isn't an issue.  Your setup looks very similar to what I have planned.