Washer Motor Repair

[duffsparky]

Hi All,

I've been trying to repair a Hitachi FW133 from the 1980's (Servis 600 series and possibly Electra something or other). The motor bearings need replacing but I can't get one of the bearings off because I can't get the drive pulley off. Any one know how to get the pulley off the main drive motor shaft. Any motor info/details that may have been stuck on the motor have long since gone, so if any one could suggest a manufacturer/supplier that might help.

I assume the pulley is either shrunk or threaded onto the rotor shaft as I can not see any evidence of splines or woodruff key fitting.

If the pulley is shrunk on, does any one know the sort of temperature required to get it off without cooking the rotor windings.

If the pulley is threaded on, I need to establish if it has is a right-hand or left-hand thread. Presumably the pulley would tighten in the opposite direction to the rotation of the rotor when the motor is under the heaviest load, but when is that? Perhaps the position and angle of the brushes could help to identify pulley thread direction? See diagram at link below.

http://www.flickr.co.../in/photostream

Kind regards.

[Whitegoodshelp (Andy)]

I'm not familiar with this model but if the drive pulley is fixed onto the armature shaft it's most probably not designed to come off. It's highly unlikely to be designed with replacing the bearings in mind although if it was made in the 80s it was common for new armatures to be available as spares (which came with bearings already pressed on).

It's likely the parts are obsolete now even if they were available as spares once - although if you get the sizes from the bearing a specialist bearing company can often supply them.

The problem is I can't see how you would get the pulley back on even if it was removed. Basically the armature has been designed not to allow the bearings to be replaced.

The motor revolves both ways so a thread isn't relevant.

[duffsparky]

Problem solved, for now at least.

As I couldn't get the bearing off the pulley end (coz I couldn't get the pulley to come off) I decided to kill-or-cure the old unit; at worst I'd have to buy a new armature (if available) or motor. So I refurbished the bearing in-place by popping off the bearing shield (which ended up destroyed), cleaned the bearing, regreased it, fitted a shield taken off the worn bearing from the other end, fitted a new bearing on the other end and voila a nice smooth spinning armature. I also got the commutator re-faced before re-assembling the motor, which is now refitted back in the machine and on its second wash; not bad for £20 total cost (£8.57 for 2 bearings [only one used] £10 for commutator re-facing and the rest for a finger full of grease. Mind you the time it has taken I could have bought several new motors if I'd been at work.

Regards.

[Whitegoodshelp (Andy)]

That's lateral thinking. Nice one. If the bearing was just dry then as long as the seal works and you used the right type of high melting point grease (I think it's LM?) it may prove to be a good repair.