Hitachi H 90SB

[staggley]

I think I have burnt the armature in my demolition hammer and have started to take it apart but I am now at the point of removing the armature and see no way of releasing it from the back bearing.

Any tricks or suggestions would be greatly appreciated.

Thanks

Staggley

[cmoorejack]

Hey staggley,
You can try and pry out [carefully] with 2 flat blade screwdrivers behind the fan [make sure the brush's are removed] or you can use the "reverse' thrust method where you strike the outer edges of the housing with a soft blow hammer forcing the armature up and out of the housing..[hopefully the bearing will come out with the armature] also be sure and check your field windings for damage..[a bearing puller is required for removing the bearing]
hope this helps..?
cmoorejack

[staggley]

Thanks cmoorejack i will give it another try, i think i have given both of these methods as much force as i thought the parts would take.Do you think drilling a 1/4 inch hole in the rear housing and pressing out would be OK.

thanks staggley

[cmoorejack]

You can do that as a last resort..best way for that is to drill 2 holes..one on each side of the outer race of the bearing [to make sure the bearing comes out whole].and then tap out with a punch going back and forth on each side till it comes out...heating the housing is also an option as long as there is no rubber nearby and you don't get it too hot..
try the heat and the reverse thrust and see if you can get some results..
Good luck..!
cmoorejack