Photos of the inside of a hub motor

[rsscott]

Does anyone know of any sites that show the insides of a hub motor? I would like to add a section on the main site for the technical side of electric bikes i.e how the motors work etc.

 

[rsscott]

If you really want to see what is inside a hub motor...........

http://crystalyte-europe.com.linux19.hostbasket.com/openhub.htm

 

[flecc]

That's not the Torq's motor though, it's the direct drive one used on the Sprint and Cruiser models. The Torq and Quando motor is very different from this, since the rotor is a completely independent open sided drum that spins around the armature, carrying bar magnets around it's inner surface. The drum has a gearwheel on it's supported side, driving three orbital nylon gears mounted on a frame fixed to the spindle, which has a freewheel mounted on the outer edge. Those orbital gears in turn drive a nylon gear ring fixed inside the hub casing, thus propelling the bike.

I didn't take photos of the Torq type's interior while I had access to it, and I don't really want to strip it all out again just for that reason, but I might just be able to produce a tech drawing or two to make it clearer for all.

 

[rsscott]

Funny, I was going to ask if you'd taken any photos!

With regard to the nylon gears, is that the best material to be using in a scenario like this?

 

[flecc]

Nylon gears

Yes, nylon is best in these circumstances. With this type of motor, the gears are in the same area as the armature with it's electrics, so it can't all be swimming in dirty oil of course. The nylon gears do have a coating of high temperature grease in manufacture, but of course that soon squeezes out from the teeth. In that circumstance, steel gears would shred in no time, but nylon can survive. Strangely enough, and not commonly known, the best lubricant for nylon is water.

You may have read reports about trouble with some early eZee Sprint motors, with the explanation that it was due to nylon gears fitted instead of steel, but there's no gears in that one illustrated above.

 

[flecc]

Drawing now on my Website

I've now got round to making a rough hand drawing of the Torq motor internals in sectioned view, together with an explanation of it's workings. Help yourself to the image if wished, or ask me for a better quality download copy. Here's the link:

http://users.tinyworld.co.uk/flecc/motor.html#bookmark6

 

[Tim]

Now that you've all seen the inside of a Sprint motor from the administrator's link, you'll know that's nonsense, there are no gears in it!

Hi, that's not the inside of the Sprint motor - I assume it's a crystalyte motor from the URL. The Sprint motor does have a set of planetary reduction gears, shown in the lower photograph taken only moments ago!

 

[flecc]

Thanks for the correction Tim, much appreciated. I assumed the first one was the Sprint motor due to the external hub type, and knew it certainly wasn't the Torq/Quando type. eZee do use Crystallyte motors though.

 

[rsscott]

Just found this animation of a brushless motor on the web:

http://www.electricwheelscompany.co.uk/brushless_motor.html

 

[flecc]

Good link Russ, pity they didn't run the animation a bit slower, though the step through is useful. Our Torq motors are inside out compared to this, the windings (stator) in the Torq are internal and the magnetic rotor is external, and constructed not of four magnets but of very many bar magnets arranged around the internal periphery. The operational principles remain the same though.