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Post by blackhorse on Feb 2, 2015 21:29:42 GMT
As mentioned before, I have repaired 2-phase and single-phase shaded pole cast-iron frame fan motors, here's some discussion. Hotpoint flat-top refrigerator condensing unit, 2-phase fan motor: Attachments:
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Post by blackhorse on Feb 2, 2015 22:04:36 GMT
I strongly recommend you try this first on a junk motor for practice. To disassemble motor I drilled 2 small holes in the back of the cast iron housing, 180 degrees apart, as close to the edge as possible (about 1/8 inch in from side), parallel to shaft. Don't drill too far in, or at an angle, or you will hit the windings. Only drill through the cast iron; do not drill the lamination stack behind the cast iron, there's a space between them of about 1/2 inch. Place the motor shaft down in a vise, loosely, with the cast iron part on top of the vise jaws and the sheet-metal front cover between the jaws, with the 2 drilled holes next to the jaws. Using a blunt end punch or drift, place through the holes alternately and tap the lamination stack (stator) out of the cast iron housing about 1/16 inch. You will see a 1/16 inch gap form between the sheet-metal front cover and the cast iron housing. Apply 2 screwdrivers between the cast iron housing and the front cover on opposite sides, and pry the front cover off (It is pressed onto the other end of the stator). Place rag in vise to catch stator, and resume tapping it out of housing with punch. Carefully drive both sides out the same amount a little at a time; if it gets crooked it will bind up on the rotor. Be sure wire feeds through the housing as the stator is removed to prevent pulling the wires out of the windings. I do not recommend removing the shaft. There are no bearings to repair; the bore is milled into the cast iron. If it's worn out, it's worn out. The retaining clip on the end of the shaft is usually a one-way fit, removing it will break it. The bearing end housing is sealed to the cast iron and retains liquid oil; remove it and the motor will leak when reassembled. View of one hole drilled in cast iron housing. There is another hole 180 degrees (other side) of the housing, hidden by bracket. Note the hole is started at an angle, and finished parallel to the shaft (straight in). Attachments:
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Post by blackhorse on Feb 2, 2015 22:27:17 GMT
After stator is removed from housing, note that the leads go through the stator and attach on the other side. I have seen 2 styles of connection; one has small paper tubes, one around each wire connection, the other has a wad of amber-colored glue poured over the connections. Unless the wires are loose and suitable for soldering to new leads, I suggest cutting the old leads about 1/4 inch from the connections, leaving a stub of the old wire to solder the new leads to. Position them so they won't touch each other, the windings, or the inside of the housing and secure them with epoxy or clear silicone rubber (bathtub caulk). Note that the stator can be installed in the housing either way; be sure it goes in the way it came out or the rotation will be reversed. Note also that it only goes in part way, it seats against a shoulder when it's in all the way in. Be sure it goes in evenly, a little at a time, or it will bind with the rotor. Since the laminations can move slightly, it's possible to bottom in places and not be in all the way in other places; observe all the way around to be sure it's in evenly and all the way. Gently, with wood blocks, tap the front cover on over the still-exposed part of the stator. View of motor reinstalled, with drilled hole visible. You can seal with silicone caulk if desired. Attachments:
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Post by blackhorse on Feb 2, 2015 22:36:55 GMT
Another view. Note sheet metal screw in hole drilled for adding oil. Hole should not be at edge of reservoir, or near center, to avoid hitting anything inside. Hole should not be higher than shaft while filling, keep shaft horizontal, or oil will leak out inside motor. Note wire leads leaving motor are white zip-cord, in a plastic sleeve, replacing original leads. Attachments:
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Post by blackhorse on Feb 2, 2015 22:37:51 GMT
WIP --
Work In Progress
I will add pictures the next time I have one of these apart.
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Post by CCL2F2 on Feb 6, 2020 21:17:31 GMT
What kind of unit is that last one?
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