Small-scale PTO

[JPC]

I'm looking for comment or reference on the following:

Because of the dimensions of an engine space, I've begun to think that a "good solution" to a need to run various belt-driven devices off of a 15hp sailboat inboard would be to have a PTO setup that took power off the crankshaft pulley on the "front" to spin a shaft running alongside the engine to available space behind the engine. The end of the shaft behind the engine would carry a pulley that would then drive the various devices.

A few other details:

--why not run off the prop shaft? -because it would not be turning at the time when these other devices would be powered.

--solid mount: If this could work at all, I would think that the "back" end of the shaft (and the devices) could be solid-mounted -that is, not vibrating with the engine. There are ways to do this with belts, but once into a shaft, I think it could just be done via u-joints and a spline coupling.

Any comments welcome. This is not my "brilliant idea" that I'm trying to convince people of; it's just a direction that would seem to make sense and I'm wondering if anyone has seen anything like it or has some thoughts, or if someone can point out why it's totally stupid so that I can look down another avenue.

Thanks,
JPC

[Robjl]

I did this two boats back to solve a similar problem.
I built a s/s angle frame (about 450mm x 300mm) mounted on small engine mounts and fitted it next to the motor.
On it was a 1" ss shaft belted to the main engine and from this shaft (also mounted on my frame) was a pump, compressor etc.
Worked well, fairly quiet.
Cheers.

[JPC]

Thanks, Robjl

Am I correct to think that your installation had no connection to the engine other than the drive belt?

And that the engine vibration transmitted through that drive belt was adequately absorbed/handled by the engine mounts that you used for your frame?

What did you use for bearings for your lay shaft?

Happy Holidays-
JPC