Yearly Motor Failure

[BCrip71]

I go through about one motor per year. I thought it was just the motors on the 646 but, I have just gone through my first motor on my new Amylior R3. It makes me wonder if I am doing something to cause the failures. I often have spasms that click the brakes on and off.

I think it is the clutch part that fails because it is all in one with the motor, I had to replace everything each time. Each time, I feel it coming. I feel the motor grabbing at low speeds. It gets louder and louder. Sometimes, on my 646, it would lock completely for a while and let go. Until it would finally seize completely. It would eventually pop and let go but, I would then not have a brake on the affected side of the chair. On my Amylior it did not eventually pop and I could not use the chair.

[Burgerman]

I avereaged around 1 motor per year for 28 years.

Thats normal if you USE the thing.

The same motors would last 10 years or 20 years if you drive it like your grandma or sit around drinking coffee.

This has been true with EMD 2 and 4 pole, 4 pole AMT, 4 pole linix, etc . Its just wear and tear.

I think it is the clutch part that fails because it is all in one with the motor, I had to replace everything each time.

As for the thing that you think is failing, it is! Well theres no clutch, its the motor coupling. See below. Common to almost every brand.

They do fail on all my chairs.
I now remove those motor couplings when brand new and reinforce them.
They do this:

Heres about 6 destroyed ones!!!

[Burgerman]

Heres one that hasnt totally disintegrated YET...


By the time they get to this stage the brushes are usually knackered too...

But in reality so is the gearbox, magnetic strength, bearings, commutator, brake etc. They all wear out together so a replacement unit makes more sense.

[Burgerman]

There IS a way to prevent the rubber cush drive coupling from failing. They fail because the outer case splits under load. Then it jams up...

I fix the case before it fails. Then they never do.
I do this on new chairs. And new motors as a matter of course now. Knowlege is power. They all fail if you actually use the chair.

By sleeving it in a stainless steel RING. A slice of exhaust tubing...

[Burgerman]

Heres a slightly split one... No good. And a healthy one! As you add torqu to the motor, the rubber tries to expand. It splits the steel case outwards.

Heres some steel tube. And a NEW cush drive rubber.

Press and loctite one inside the other! I used a vice.

Then it looks like this. Uneven... File off the uneven edges. And then refit. Now it will never fail ever again. But something will!

[BCrip71]

Thanks. Good to know it is not me.

[Burgerman]

No. Most people never see this. They float around with "hovercraft" programming or move like a lump of driftwood. I drive it like I stole it all day. And they break!

I did the same to cars (gearboxes, engines, brakes) and motorcycles all my life. What can I say. I am a hooligan. If you insist on getting 101% max out of something they fail. The manufacturers dont see a problem because they send out 100 and get 1 back.