Thomas Transmission

The most interesting early setup ve seen is called a "Couple Gear" used in a truck pre WW1.......Ive .only seen bits of the drive ,but it appears both the armature and field frame rotated in opposite directions ,and each component was geared to one side wheel

I read somewhere maybe here, about an enormous old road train for want of a better term. Up front was the driver and a huge engine that drove a generator then the power went back to all the following wagons and drove each axle that had an electric motor. It was used in Victoria, I think for carting wool or wheat. It did one trip and was outdated. It was a German design and build I think and cost a small fortune and weighed an awful lot and had issues crossing bridges.

I think that is grandads first pic......IIRC,at the start of WW1,the German operators and mechanics all went home to avoid internment....(staying would have been a better option).........there was a similar german machine bought to dredge the Kow We Rup swamp,but locals kept it going after the Germans left..

I will have to look up the alternator driving AC motor bit. AC motors have bugger all torque at a standstill. I wonder if they're coupled like a Selsyn drive. That is two wound - rotor motors (with slip rings) with the rotors electrically connected. The stators are powered. When you turn one, the other turns precisely the same amount (unless you have switchgear and resistors in between).
Paul (Mrs Mack) may have worked on these. (Express - Westinghouse lifts)

There are so many ways of setting up a motor - generator set driving other motors, the mind boggles.

Jarrod.

When I was an apprentice we had to couple 40Hz and 50Hz motors together in an MG setup, depending on what the parent frequency was on that particular level dictated what end you applied power to and which end you got the power from.

Anyway, back to the project, the fiddly bit was finding an epicyclic gearbox that wasn't too big and needing a fair bit of power to turn it plus an axle and a motor and a means of getting two paths of power to the wheels etc. etc. Then one day I had an idea which would reduce the size and solve a couple of issues, so off I went to the local mobility shop who kindly let me rummage in their scrap bin and have a couple of rear axles from old mobility scooters. My thinking was to use a differential as an epicyclic gearbox, and the scooter axles size made it much more manageable for me to handle.
The next bit was to sort out how to drive the diff, and I had to decide on a power unit to suit the size of the axle.
I came up with the idea of using an engine from a strimmer, seemed about the right size for it, just needed a way of sorting out how to transmit the power. Didn't have a great deal of choice so I used some bicycle bits to do it with.
Here's the first stage, now don't laugh,,,,,,

I used a 25cc engine from a strimmer and modified the centrifugal clutch to engage at a higher speed, as I found it didn't have enough guts at the bottom end. I then welded a bike sprocket to it as I wanted to drive the diff at a higher speed than the electric motor could manage. The diff ratio was 20:1 so driving through the motor shaft was no good, I needed to modify the crownwheel to alter the ratio.



To be continued.....

Im intrigued, It is always amazing the different things that come across this forum

For those of you that didnt know (like me) a strimmer is what we call a whipper snipper in Australia or (correct me if Im wrong Brocky) a weed wacker in the States

Paul

Newie on me as well! I had to ask Mr. Google.
Unsure where we are going with this particular exercise, but I'm in, has got me intrigued as well!

Up until now I had trouble differentiating the complexity of AC vs DC! Then you guys hit me with Selsyn Drives!
At least you can learn something here on this forum, better than looking at pictures of blinged-up pus- buckets that will only travel to shows!
(There, that should get a bite!)
Dave_64

asw120 wrote:

I will have to look up the alternator driving AC motor bit. AC motors have bugger all torque at a standstill. I wonder if they're coupled like a Selsyn drive. That is two wound - rotor motors (with slip rings) with the rotors electrically connected. The stators are powered. When you turn one, the other turns precisely the same amount (unless you have switchgear and resistors in between).
Paul (Mrs Mack) may have worked on these. (Express - Westinghouse lifts)

There are so many ways of setting up a motor - generator set driving other motors, the mind boggles.

Jarrod.

Yes the GMC Express used Selsyn drive to drive the selectors

For those of you that have never been involved in the lift or elevator industry a selector is like a scaled very precise model of the lift shaft and on some brands of lifts tells the lift car were to stop start , when to accelerate and de-acclerate and is 100% repeatable for the entire buildings life unless the lift mechanic changes it

So GMC Express used Selsyn drive and the biggest user of selectors that I know of, Otis used a steel tape right up into the 90's

I was always told the Selsyn drives were used on ships to relay signals or controls from the bridge to different parts of the ship


Back to you grandad

Paul

Grandad That is fascinating stuff. It is way past my level of knowledge or understanding but I love what you are doing.