I'm not sure whether this question belongs in this forum since it's actually about the mechanical aspects of alternators as opposed to their electrical
aspects, so apologies in advance..
After reading through a bunch of posts about how many people are running 4 trillion amp alternators completely lopsided off their small engines, I decided to bite the bullet and follow suit...
After doing some research
on this topic, it appears that the biggest problem is indeed side load, and stalling the little engines at idle etc.
So to solve both of these problems, I decided to go for TWO industrial alternators which don't put anything
out below about 2000 (alternator) rpm
, and to have a new crankshaft pulley fabricated such that I can have 2 x 1/2" belts on each alternator
, and mount them in front of the engine
backwards, on either side of the crankshaft pulley such that they are exactly opposite each other.... voila! no side load (theoretically).
(the alternators are mounted on a big hunk of steel
that is bolted to the engine
mounts - on the engine - not the bed
- so the engine and alternators move together)
Now, my question here is - since I have two alternators directly opposite each other, on a common base, with the crankshaft pulley in the middle - can I use a large turnbuckle or threaded rod between the upper alternator mounting holes to tension both alternators at the same time?
My theory here is that by using a central common tensioner and pushing the alternators away from each other this way, the load on the crankshaft pulley will always be balanced.
Am I missing something or is this OK?
attached showing the mounting base for the alternators and pulley (without the alternators mounted yet though although the two alternators are Bosch BXU12121A's (120A),) and the brand spanking crankshaft pulley has three pitches: 70mm for water
pump per original pulley, 110mm for watermaker
at high pressure pump at 2800 engine rpm - yanmar
manual states that this is ideal cruising rpm for this engine - highest power for lowest fuel
consumption), and finally 155mm for the alternators.
Pulley is machined from K1045 high carbon steel
, which I'm hoping will be strong enough to deal with the short shaft and long overhang, despite the loads being well balanced).