this is called a pony motor (although John Deere calls it a "Cranking Engine") and it cranks the main engine with a pinion gear just like an electric starter.
This one is a two lever unit - one lever (on the left) to engage the drive pinion into the ring gear on the main engine. This would be done while the pony motor was warming up.
Once the pony was warm the second lever would engage a clutch between the pony motor and the drive pinion to turn the main engine. (There are also three lever models where the third lever would allow you to select either high or low gear on the pony motor.)
Once the main engine started it would automatically kick out the drive pinion from the pony. In cold weather the pony motor may have to turn the main engine for 20 or 30 minutes before starting. The pony motor shared its cooling system with the main engine and the exhaust pipe from the pony was routed through the intake manifold for the main engine in order to warm it up.
This was a great system for a few reasons. First the main engine never started without first building up oil pressure. Second, since it took some time to start, the operator had an opportunity to check the machine over and grease fittings while waiting for the machine to warm up. Thirdly, time was on your side. The longer the pony motor cranked, the more likely the main engine was to start (unlike electric starters).
then they used the running dozer to bump start the 2nd dozer that doesn't seem to have a starter motor
Commonly known as a "pony motor"
ReplyDeleteHuh! Thanks!
DeleteYup.
ReplyDeleteAlso used as a compressor motor to fill an air tank to drive an air motor to start a diesel engine. You still see and hear them in city buses in San Francisco. Vreep!
Great video.
now THAT makes sense! Stop by any garage and top off your air tank! Or, just rent them from a compressed gas company that sells Nitrogen, argon, oxy acetlyene, etc
Deleteno wonder they left them idling for hours at a time.
ReplyDeletein the early 90s when I was an Owner-operator I drove an old 18 wheeler that was really hard to start in cold weather. and i would leave it running all weekend if it was going to be below 25 degrees, Id just bump it up to a fast idle and leave it running for 60 hours
used a bit of diesel, but them on Monday morning, I was ready to roll and other drivers who had shut theirs off on Friday would spend all day trying to get their cranked, and usually the only way to crank it was pull it about 1/2 mile with another truck
on a side note, pony motors are used on some electric motors, if you have a 3 phase motor but dont have 3 phase power, you can use a small electric motor to spin up the large one, and then turn the power to the large 3 phase motor on after its spinning , and the 2 phase power will keep it spinning, but it wont start it up
Wow, i've always wondered why truckers leave the rigs running forever. I thought it was for the AC to keep them cool while sleeping or something
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