Accessory Drive

Once upon a time cars had one fan belt, and it was a V-belt. It ran over three pulleys:

1. the crankshaft
2. the water pump
3. the generator

The generator was mounted on a pivot bracket and was equipped with an adjustable strap to set the tension on the belt. Later on we got alternators. Then came power steering, air conditioning and air pumps (also known as smog pumps). They were all driven by V-belts. On some cars you could have as many as six V-belts to run all this equipment.

Like all mechanical devices they would wear, and eventually fail, and if the belt that failed was the one farthest back on the crankshaft pulley, you had to remove all the others from in front before you could replace the broken one.

Of course this was before the invention of the serpentine belt. The serpentine belt is quite a little miracle.

Before we got to the serpentine belt, back when we were at the height of the fan belt madness, I was thinking that there had to be a better way to drive all these accessories than the way we were doing it. My solution was to provide a gear inside a housing at the front of the engine. The housing would have several holes on the front side that would accommodate a hub on an accessory device. The holes would be machined so that simply sliding the accessory into the hole would cause it to be perfectly aligned with the gear inside the housing. A simple clamp would hold it in place.

But then along came the serpentine belt and my idea never really got a chance to take off.

Update February 2017 replaced missing image.