Removing cover from hub motor

[Tincan]

Evening Gents!

Hopefully this will be a nice easy one.

Had a bit of a search around and still no closer to working out how to pull my hub motor apart.

It's one of the Chinese cast 16" hub motors. I can get the sprocket side off no worries at all, easy access to the hall sensors. Can remove the stator from the wheel as well.

Where i am banging my head is actually getting the other side off. I'm wanting to get to the phase wires to upgrade them as i have a Lyen controller coming.

Is there something really silly i'm missing here? I have all the brake assy off, was done anyway as i have the disc brake conversion kit too.

Any help would be great. If you need pics, ill post some up.

Shane.

 

[RallySTX]

Show us a pic, we like pics!

 

[dogman dan]

A largish gear puller should be able to push the axle out of the bearing on the other side.

 

[John in CR]

Some don't have a cover at all on the other side. If you can get the stator out, then what is the issue, since the phase wires are just on the other side of the stator? For one I had with a single cover, I had to clamp the axle flat in a vise on the wire side and shove the rotor down until the magnets cleared the lams. The vise was to avoid damaging the wiring harness, which came out through the axle. Once the rotor was clear, I put 2 strips of wood between the stator and rotor before loosening the vise and pulling the stator all the way out. This was a several KW motor with strong magnets, so you really have to watch your fingers, and the wood was to prevent the rotor from slamming back onto the stator violently.

 

[Kingfish]

Here is a related thread: How the hell do you get the 9c motor cover off!?

Hope this helps
~KF

 

[Tincan]

Thanks for the idea with the puller!

As for what does it matter if i can get it out of the wheel? well the wires i want to access are on the side that is still coverd!

Everyone likes pics!

 

[docnjoj]

I use the "wack the axle on a block of wood on the ground while holding on to the cover" trick. Definitely protect the wires by taping them up away from the axle end but leave plenty of slack on them so they wont break. It should slide out and free the bearing from the axle. I'm sure there are more elegant ways like the giant puller. Good luck.
otherDoc

 

[John in CR]

For future readers of this thread, with a wire in axle hubbie, get the wire side cover off first, which is typically easily loosened with a sharp object and pried with several. Then you can use the hold the rotor and bang the axle straight down on a piece of wood on the ground, and once the cover comes loose from the bearing you can just push the magnet ring with cover still attached right off.

The problem with saving the wire cover for last is things are trickier. You'll damage the wire if you try banging that end on anything. There's nothing to pry against without easily damaging the stator, and you'd need some kind of adapter to use a pully puller with the wire harness in the way.

What to do now? If you have a vise, clamp the wire side axle in the vise and knock on the cover with a couple of pieces of wood, or you may be able to apply pressure and wiggle it. Bearings need changing anyway, so don't worry about the side force damage to them.

Probably the easiest thing is to suspend the assembly by the cover with the non-wire axle end pointing down. 2 stacks of books so that axle end is about 1" above a piece of wood would be perfect. The stator will fall loose once the bearing comes off, so if it's high you need to hold it to catch it. Then put the nut on the axle wire side and use the nut to tap on with a hammer along the axle flats. Another way at this point is to pull off the black rubber seal that covers that bearing, and with a chisel or other object hammer directly on the bearing until it comes out of the cover. The bearings are stuck much more firmly to the cover than the axle, so that takes more force to get them out, than to tap it off the axle.

Hopefully those explanations weren't as clear as mud.

John

 

[ZapPat]

I don't think anyone's mentioned this yet, but I've found that the round axle part (just after the flats/threads) gets squished when being tightened onto an ebike. This makes the end of it become wider (of a bigger diameter) than it originally was, and thus makes it very hard to slide the bearing back over it. I don't know if this is what's happening with your motor or not, but I've had it happen pretty much every time I tried to take apart a used 9C hub.

The solution was very simple for me: just take a file and file down the area on the axle just after the flats/threads. If this is really the problem, you will see that the axle is just slightly larger at this point from being squished during installation. Rotate the axle as you file that lip back down to it's regular size. After this, the bearing in the cover should be able to slide all the way off easily instead of jaming on that slight lip.

Pat

 

[dmould66]

is there a special procedure for replacing the covers because i took both covers of a brand new hub i bought on ebay, didnt disturbe anything else, now it wont turn smoothly?

 

[John in CR]

is there a special procedure for replacing the covers because i took both covers of a brand new hub i bought on ebay, didnt disturbe anything else, now it wont turn smoothly?

What exactly do you mean by not turn smoothly? Is it like something rubbing inside, or more like many small bumps or jerks as you turn it by hand. If the latter, then it's probably just the ends of the phase wires touching each other and shorting which results in plug braking. If only 2 are shorted then it will feel quite rough.

 

[Tincan]

Hi guys.

I totally forgot bout this.

I ended up removing the cover by essentially banging the axel on the carpet. Moving the wires to the side so it doesnt get damaged of course.

The bearing as you can see was what held it in place.

When i was putting it all back together i noticed it was hard to turn and made a scraping sound.

This was from the bearing not being pushed back far enough into the cover.



You can see the bearing im talking about here.

Also found out at the same time the motor is an 8x8