Elektric motor bearing replacement

[Ivarsson]

My 2015 i3 have started to develop a mechanical wine after 163000km, after it bit of digging around on the internet it seems most likely candidate are the bearings in the motor. Due to being a mechanically savvy cheapskate the question of replacing them instead of the entire unit occurred.

Have anyone actually successfully replaced the bearings in the emotor? (instead of the entire unit)

What are the bearing dimensions?

(already checked through munrows teardown report of the e-machine and the technical training manual but without any real help)

 

[Ivarsson]

Had a link towards a russian guy who documented the bearing change (poorly) on youtube. If it worked correctly after the change i do not know. The critical part is the rotor position feedback sensor, should also be whats calibrated, but he seemed to have just marked the position (unsure if it is just a pressfit or indexed)

https://www.youtube.com/watch?v=X3cpr8njfAk&ab_channel=i3MoscowClub

 

[Ivarsson]

The powerpack is on a pallet now and the new bearings are in their way. Started the process of a reasonable DIY dissasembly/assembly method. (as ushual with a PMSM motor, you will have to fight the permanent magnets magnetic fields doing this). WIll try to document the procedure for future reference.

 

[Ivarsson]

Bearing is now changed, car is up and running writeup of procedure will come in the next few days.

 

[mojo]

Was it an industry standard bearing size? If so it must have saved you a lot of money!

 

[Ivarsson]

Bearing sizes for electrical motor were (2015 i3 REX)

6006 and 6306 and it were the smaller of the two that failed.
Please be aware when selecting bearings the tolerance and rpm, due to it being relativity high for the bearing size, up to 11300 rpm.

The bearings i selected were:
6006 2RZ Deep Groove Ball Bearing - SKF
6306-2RZ/C3GJN 30x72x19mm SKF Deep Groove Ball Bearing

Hopefully they will last a bit better than the originals.

A larger post regarding the bearing change is coming. Please be aware, this fix is not a quick or easy fix.

 

[ronbot]

Have you had any issues following the bearing replacements?

How were you able to get the rotor re-installed exactly in-sync with the resolver - so that the inverter still had the proper stator/rotor timing ?

 

[Suttyo]

HELP !! the engine bearing needs to be replaced urgently, but it is difficult because of the rotation sensor. RONBOT, if I saw correctly, you were also looking for the solution, did you succeed? [email protected] Hungary

 

[Rolphmao]

did we ever get a procedure? the linked vid is private and this thread seems to die off without much doc

 

[Dutchi3]

PM/Reluctance motors are not that uncommon, why couldn't the bearings be replaced by a specialized company that restores those type of motors? Bearing failure must be a common thing and electric motors are being serviced for more than a century. So why d.i.y.? Shure, it saves some bucks. Buying another (secondhand/salvaged) motor is also an option, but the resolver has to be programmed then and the bearings may also fail after a while.

 

[JoeCool88]

PM/Reluctance motors are not that uncommon, why couldn't the bearings be replaced by a specialized company that restores those type of motors? Bearing failure must be a common thing and electric motors are being serviced for more than a century. So why d.i.y.? Shure, it saves some bucks. Buying another (secondhand/salvaged) motor is also an option, but the resolver has to be programmed then and the bearings may also fail after a while.

Here a video where some guys disassemble the motor . It does not seem to be their plan to put it together again, however minute 20 onwards of the video shows that it is possible for one person to pull the stator, if two others hold the casing with the rotor. The flanges for the bearings seem to be bolted to the rotor, which makes bearing replacement easier. Sure the rotor position sensor has to be installed in exactly the same position as it was before. But this must be possible, if carefully marked before removal. For the removal and installation of the bearings I personally would invest in the best tools on the market. And comparing the price for a new motor with a pair of bearings and the fact that the replacement is definitely no rocket science, I 100% would give the job a try