I agree. My brother owns a Case tractor with hydrostatic drive and it has a nice hyrdraulic powered snow blower that needs no less than 5 HP to operate. The drive requirements look exactly like what my compressor head needs. The tractor has had a new short block, and a new clutch... But has never required any service of the hydraulics.
I have never seen a hydraulic powered shop and auxillaries from a stationary engine before. But I was thinking about how to solve this problem and I am settling in on a hydraulic drive for my engine room.
I had a dream awhile back when I started thinking about this: I saw myself caught in a belt. I felt the jerk and pull and just had time to think "uh oh" and everything went black.
A perfect system for me would be a central equipment mount for engine, flywheels, belts, pulleys, primary generator, and hydraulic pump. Conduit the utilities down thru the equipment mount block and under the floor. This leaves the walk around area clear of cables, lines, and hoses. Utilities overhead would include exhaust, air intake, and cooling system, which would be removable for overhead hoist operations. An elbow high gate cage with lift off sides would screen off the moving parts from the rest of the room. I can pour the foundation block with holes in the corners for inserting gate posts.
I was talking to an engine guy awhile back and he said much of the problem with light flicker and governor hunting were resolved by bigger flywheels, and he said that for pulling generators the bigger single cylinder engines worked well because of their massive flywheels. We talked about adding mass to the Lister type twin crankshaft to increase the stored angular momentum in the system and we both agreed the better solution was an auxillary flywheel on its own bearings.
An auxillary flywheel shaft with a clutch would be the ideal location to remove rotational energy from the system. I have heavy inductive loads balanced by capacitors that look like a dead short for a tangilble fraction of a second on startup, and pure inductive loads are planned, like an arc welder. I am confident the engine will drive these loads easily once the rack gets opened up a notch, but these loads are "bumpy"; not smooth like a resistive load and you don't want the voltage drop and surging every time you energize a big welder core. It is hard to resolve governor issues that only present themselves during high load pulsed applications when both hands and eyes are occupied elsewhere. This type equipment can rob energy out of the flywheel virtually instantly and start right up, before the rack can respond to the load.
The flywheel need not be subject to engine vibration, especially if you pour separate (engine -|- load) block mounts with felt isolation padding between them. Run the engine belted to the flywheel shaft. Flywheels are simple machines, there is not too much to take care of or go wrong with, you put grease fittings on the bearings or add drip oilers.
(http://peswiki.com/images/b/ba/Spoked_flywheel_animation.gif)
http://peswiki.com/index.php/PowerPedia:Flywheels
The free shaft ends make an attractive mount for two opposing direct drives; and gears, pulleys, clutches, transmissions, hydraulic pumps, generators, whatever, can be run belted or direct shaft driven from either end of a flywheel shaft. Belted or geared loads can be placed on the shaft between bearings rather than being hung out on the end.
(http://importnut.net/forsale/b-flywheel-2.JPG)
http://www.novak-adapt.com/images/pics/clutch_disc.jpg
If you bolt together something like a 15 inch diameter truck or big tractor flywheel as part of the rotational mass, you get a starter gear and a clutch face. People will say something about efficiency, but a flywheel does not use much energy once up to speed, it is an inertial storage and energy transmission device. It makes the power supply look much bigger than it is when using loads that have high peak energy demands. The flywheel makes the system less elastic, counter balancing both engine and loads, giving and taking energy between them, smoothing out power delivery.
Since you can get cheap used flywheels in steel, it's easy to bolt up something ugly but heavy, static balance it, put a nice looking cover over it (bell housing?), and run it with a shaft speed of 1800 RPM. Direct drive the generator from one end of the shaft, and clutch the hydraulic pump off the other end.
The ability to use truck and tractor parts reduces the cost, and you can end up with a high performance flywheel system. Industry has advanced the technology, but the benefits are the same:
http://www.afstrinity.com/other-facts-faqs.html