I have a Wolf-Garten lawnmower with a 1600W electric motor. A couple of
years ago the motor would not rotate and just gave a loud hum on trying
to start. It was checked by the service agents (fortunately still under
guarantee), and repaired by changing the capacitor. Last week it seemed
to have developed the same fault, so I replaced the capacitor (30uF
450v). Unfortunately this did not cure the fault, and the only way I
could get the mower to start was to push the blade with a long stick!
But once stopped (eg to empty the grass box) I had to use the stick
method to start it again. Neither convenient nor safe...

So I took the motor apart. It would not rotate until I got the
non-spindle end casing off. I found damage on the non-spindle end of the
rotor (ie the end furthest from the blade), apparently caused by a
spring-loaded part (see red arrow at http://tinypic.com/r/e5r9sg/9)
which appeared to be caused by the part marked with the blue arrow.
There were three of these which were extensions of the dome at the left.
I sprayed WD40 on both ends of the dome and succeeded in moving it. It
then moved freely up and down the rear rotor spindle on hidden springs.
The movement allowed the extension parts to hit the rotor parts showing
damage. I guess this is a brake intended to have a similar purpose to
that at https://en.wikipedia.org/wiki/AC_mot...ng_rotor_motor. Can
anyone confirm this?

Anyway, on replacing everything, including the old capacitor, the motor
started well, but there were definite clonking noises as it started. I
haven't tried mowing the lawn yet, but will have to in the next couple
of days. The motor (marked Ningbo Racing/Hujiang Electric 1116000) €Žwill
probably need replacing but doesn't seem to be available, having perhaps
been replaced by the GJC-1600 at
http://www.chinahujiang.com/lawn_mower_serial_motors_04.htm although I
can't see any suppliers of that in the UK either.

Anyone got experience with this type of motor?

--

Jeff