ecolometrics
Plastic
- Joined
- Aug 12, 2019
I have a 3ph 3hp that came out of an AC unit with bad vibration. I got this motor for free. The run-out on the pulley was clearly visible. I thought the bearings went bad. The front bearing spun well, but the rear ones did not. But after then measuring the bearing run-out (rear 0.0005in, shaft stationery) and the shaft run-out (rear 0.025in, rear bearing stationery) it seems to be the shaft. There is a rub line at the half inch mark from the lathe chuck, which also shows run-out (which confused me at first).
I have taken some notes from this: https://www.practicalmachinist.com/vb/general/repairing-induction-motor-rotor-shaft-336890/
What kind of metal is suitable if I made a new shaft? Would a Chinese 2hp 13x40 lathe be sufficient to turn a new one?
Getting the rotor off. From what I read from the other thread above the rotor is shrink fit. I would have to heat up the rotor body (I read 400F, with a torch?) and push it out with a press (I have a 12 ton) or a sledge hammer. The rotor has aluminum fins. Should I make a jig or go up against the fins with a 1 inch plate?
The shaft is about 30mm diameter at the rear, but gets wider after the rotor. The bearings are 6206 and 6205. Motor is "U.S. Electrical Motors" brand 3ph, 3hp, 1740 rpm.
I have taken some notes from this: https://www.practicalmachinist.com/vb/general/repairing-induction-motor-rotor-shaft-336890/
What kind of metal is suitable if I made a new shaft? Would a Chinese 2hp 13x40 lathe be sufficient to turn a new one?
Getting the rotor off. From what I read from the other thread above the rotor is shrink fit. I would have to heat up the rotor body (I read 400F, with a torch?) and push it out with a press (I have a 12 ton) or a sledge hammer. The rotor has aluminum fins. Should I make a jig or go up against the fins with a 1 inch plate?
The shaft is about 30mm diameter at the rear, but gets wider after the rotor. The bearings are 6206 and 6205. Motor is "U.S. Electrical Motors" brand 3ph, 3hp, 1740 rpm.