TSDZ2 Bare Motor Strip-down

• I have two bike builds with the 36v 250w TSDZ2 - one of the TSDZ2 units is whisper quiet and the other annoyingly noisy
• Now, I've done all of the usual bearing checks, greasing and so on without any improvement, so out of desparation I swapped the bare motor units between bikes and it is the bare motor unit that is noisy, definetly
• So I stripped the noisy bare motor down - no signs of surfaces rubbing nor overheating (hardly suprising given my gentle riding style).
• The rotor bearings seemed fine when rotated by hand so I'm left with wondering my this bare motor is noisier than the other one - any clues folks?
• The only thing I haven't done is separated the rotor from the motor casing cover for visual inspection and maybe replacing the bearings in case one is noise under load - can anyone advise on how to remove the rotor and bearing from the case cover?
• And can Hall Sensors 'play up' in that they don't give a clean 'switch' (as in some sort of switch bounce akin to mechanical switches)?
• And why would one BLDC motor be so different from the other, especially given their very simple construction?
• 

• So I swapped over the hall sensors between the bare motor bodies and the noisy motor stayed being the noisy motor, but at least I've eleminated the halls sensors as the cause of the problem.
• The noisy bare motor is back on the bench and during strip-down I saw how to separate the motor casing head from the rotor - it just pulls off - lol
• Next job is to remove the three bearings shown in Fig 5 in post #1 and there is another bearing on the rear of the rotor
• I'll keep this post updated as I move along and put some pics in that others might find useful.

• In answer to my own question, the rotor spindle can be removed from the motor casing by first removing the black connector block which exposes the spindle end, then a light tap with a suitable drift will spearate the spindle from the casing.
• Using a drift might not even be necessary - a sharp tug by hand might be enough.
• On the spindle end is a wave washer, then a 698 RS bearing followed by a 0.5mm brass shim washer that sits between the bearing and magnet assembly.

Rotor​

Rotor Assembly​

• On rotor spindle 1 place bearings 2, 4 and 6 with shims 3 & 5 between bearings 2/4 and 4/6 respectively.
• The bearings and shims need to be pushed down onto the spindle splines far enough to allow the reinsertion of the circlip 7 into the spindle indent shown by the arrow. Figure B is a close-up of the spindle showing where the first bearing 2 engages with the splines.
• Insert key 7 into the keyway on spindle 1 and then push the rotor magnet assembly 8 onto the spindle 1, then shim 9 and bearing 10.
• Place wave washer 11 into the bearing cup in the bare motor case top 12.
• Place the spindle assembly into case top 12 which will likely require some light tapping with a mallet to get bearing 10 seated adequately.

seattlesockey said:

Anyone replace the brass shims and wave washer? Where did you find them?

Click to expand...

bikes4two said:

I've ordered up replacement bearings (4 in number) but in the meantime I've knocked up a diagram and documented (in draft) some info which others might find useful.

When I've re-assembled everything with the new bearings, I'll update this post as to whether the noisy motor is no more - fingers crossed!

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Rotor​

Description	O/D​	I/D​	W​	No​
Wave Washer	18​	12.5​	0.4​	​
Single Bearing – spindle/case	19​	8​	6​	698 RS​
Brass Shim	12​	8​	0.5​	​
Three shaft bearings	19​	10​	5​	61800 RS​
Two brass shims (sit between the three bearings)	14​	10​	0.1​	​

Motor Casing screws – pozi head, M3 x 48mm (replaced with new screws as the original screw heads were damaged during disassemble as were very tightly fitted and head material is on the soft side).)

Rotor Assembly​

• On rotor spindle 1 place bearings 2, 4 and 6 with shims 3 & 5 between bearings 2/4 and 4/6 respectively.
• The bearings and shims need to be pushed down onto the spindle splines far enough to allow the reinsertion of the circlip 7 into the spindle indent shown by the arrow. Figure B is a close-up of the spindle showing where the first bearing 2 engages with the splines.
• Insert key 7 into the keyway on spindle 1 and then push the rotor magnet assembly 8 onto the spindle 1, then shim 9 and bearing 10.
• Place wave washer 11 into the bearing cup in the bare motor case top 12.
• Place the spindle assembly into case top 12 which will likely require some light tapping with a mallet to get bearing 10 seated adequately.

Edit: on re-assembling the stator/rotor, the two are held together by six M3 screws with Pozi heads. The heads are soft and were showing signs of damage from several unscrewings, so we're replace by new M3 x 50mm screws, four of which had to be reduced to 48mm.

Click to expand...