HVAC Blower Motor Repair.
08-26-2015, 07:18 AM
#1
Rennlist Member
Thread Starter
HVAC Blower Motor Repair.
Hi All,
After searching through the forum I couldn't find if anyone had replaced a worn out commutator and carbon brushes in their HVAC blower motor, so I decided to pull it apart and see how it was constructed.
Be careful when pulling the motor body apart that you note where the washers came from and what order to put them back. I found that the metal plate that houses the bearings on the end of the motor body was crimped to the body. I used a hammer and punch to push back the crimp as far as possible, then a screwdriver to prise the plate off. When re-installing I tapped and clamped the plate back into position and used a hammer and solid steel screwdriver to peen over or crimp the metal plate back on.
I found that the commutator was not connected to the windings by soldering, but by copper tabs that crimp to the windings. This makes it relatively easy to remove the commutator after carefully bending the tabs down far enough that the commutator can be pulled off the armature shaft without damaging the windings (see photo of my old commutator after removal).
I found a commutator of the same size and style on ebay (from China) and reinstalled on the armature shaft. I had to bend down the tabs on the new armature to be able to loop the winding over the tab and re-crimp, also make sure the tabs and section of winding that makes contact are perfectly clean before connecting. Don't put too much stress on the wires while trying to do this, if the insulation gets damaged in the winding, the armature will be useless.
The old brushes are easily removed by un-soldering the connection, replacing with new 8mm square and 14mm long brushes and re-soldering.
I did not do anything with the bearings, except a bit of extra lube.
Unfortunately I did not take enough photo's of what I have done but I have attached some photo's to help explain my description. I managed to scratch the new commutator a bit when crimping, but it cleaned up O.K. with some 240 grit paper.
I have run the motor for about 15 minutes so far, and all is O.K. I suppose I will find out how successful the work was in the coming years.
Cheers,
Gary.
After searching through the forum I couldn't find if anyone had replaced a worn out commutator and carbon brushes in their HVAC blower motor, so I decided to pull it apart and see how it was constructed.
Be careful when pulling the motor body apart that you note where the washers came from and what order to put them back. I found that the metal plate that houses the bearings on the end of the motor body was crimped to the body. I used a hammer and punch to push back the crimp as far as possible, then a screwdriver to prise the plate off. When re-installing I tapped and clamped the plate back into position and used a hammer and solid steel screwdriver to peen over or crimp the metal plate back on.
I found that the commutator was not connected to the windings by soldering, but by copper tabs that crimp to the windings. This makes it relatively easy to remove the commutator after carefully bending the tabs down far enough that the commutator can be pulled off the armature shaft without damaging the windings (see photo of my old commutator after removal).
I found a commutator of the same size and style on ebay (from China) and reinstalled on the armature shaft. I had to bend down the tabs on the new armature to be able to loop the winding over the tab and re-crimp, also make sure the tabs and section of winding that makes contact are perfectly clean before connecting. Don't put too much stress on the wires while trying to do this, if the insulation gets damaged in the winding, the armature will be useless.
The old brushes are easily removed by un-soldering the connection, replacing with new 8mm square and 14mm long brushes and re-soldering.
I did not do anything with the bearings, except a bit of extra lube.
Unfortunately I did not take enough photo's of what I have done but I have attached some photo's to help explain my description. I managed to scratch the new commutator a bit when crimping, but it cleaned up O.K. with some 240 grit paper.
I have run the motor for about 15 minutes so far, and all is O.K. I suppose I will find out how successful the work was in the coming years.
Cheers,
Gary.
