Not much of a shock load, the clutch slips to reduce the shock load. The
mass of the flywheel is so sigificant that the voltage never did a noticable
dip when AC mains was lost.

Saw one of these in an old hospital years ago. It looked like it may have
been a steam driven gen set at one time. The flywheel was huge and was the
generator. It had an electric motor on one side to drive it during normal
use and a diesel on the other side with a mechanical clutch that was
controlled by loss of incoming power.

As I understood it the flywheel only powered part of the OR (1 or 2 rooms)
where they did open heart surgery. The flywheel stored enough energy to let
them finish a open heart procedure using a heart lung pump. The time frame
would have been early 1950's at a major univerisity medical center..

It was still in use in the middle 60's. I am sure it was from the late
1800's to early 1900's. I suspect they just torched off the steam cylinders
and removed the connecting rod to make the conversion.


Hugh



"Tom Miller" wrote in message
...
I've heard of standby generators that had a flywheel starter. The flywheel
was kept spinning by a mains powered motor. When the power failed,a clutch
engaged the flywheel to the genset and it was up and generating power in
seconds. I suspect that there may have been a few crankshaft failures as
it
would be a pretty heavy shock load on start up.


wrote in message
oups.com...


Tom Gardner (nospam) wrote:
"habbi" wrote in message
...
How do the gas powered golf carts starting system work. When you
apply
the
brakes the engine shuts off and then when you press the gas pedal
the
engine
starts and you drive away. Why hasn't this technology been used in
automobiles?

Actually, GM had a truck on the road to prove this technique out. It
had a large battery pack/bank, and the truck actually ran on
Electricity initially or to get going. The key part of this system was
not a traditional Starter, but a completely reworked starting system
hat virtually was built around the trucks flywheel. It in itself was
both an AC generator that put out common household voltage, AND a
Starter. Having those large dimensions really made it more or less
equivilent to being an electric only vehicle if necessary, but
electronics allowed the engine to start as soon as possible because the
design did not use an "endless" source of DC power from a large battery
bank similar to what would be found on electric only vehicles.

To me, that system looked to be as good as anything, and it would have
been a real benefit to have that 120V AC built in !

Back to Golf Carts, most use a simple belt driven "Starter/Generator"
similar to what was found on older Lawn tractors. You can do an Ebay
search on the two words together and see plenty of them. Garden Tractor
ones usually only put out 15 amps tops, while I think the Golf Cart
ones do around 30 amps.

These things make nifty DC charging systems in Motorhomes, as you can
cobble together some electronics that will make a motor "autoStart"
when the batteries are low, and shut down after charge float time or
pure timer functions. Very nice if you have an RV or Tool Truck set up
with 12v to Inverters rather than relying on AC generation all the
time.

Grummy