sintered oil impregnated spherical bronze bearings

Thank you. My microwave is 30 years old and I've had it out 4 times, oiled and removed the bearings to change front to back and visa versa. Bearings seem tight and something starts making noise like the bathroom fan. Couldn't find a motor or bearings for replacement and could not get a hammered shim <.001 between shaft and bearing. Finally carefully squeezed spherical bearings to snug them to the shaft. Worked great for 5 minutes and started vibrating noise again. Sometimes, stopping vibrating fan stops noise, and it restarts quietly and starts the noise in minutes. I checked blower, and housing and can't find source of noise, other than it being from the bearings. Where do you buy spherical bronze oiled filled bronze bearings? The motor shaft is about 1/8 diameter, and the fan is a scroll nylon blower. Anthony

I've found a few at my local hardware stores, but this site has a much larger selection.

http://www.mcmaster.com/#oil-impregnated-bushings/=3wz4li

I use McMaster for many hard-to-find items. For the parts I've ordered prices were quite acceptable.

Sometimes you just can't find a replacement bushing. On a few rare cases, I've modified the motor to run on ball bearings.

http://www.amainhobbies.com/index.php/cPath/1_25_63?gclid=CM-b3Pn8o50CFYZM5QodnBT57w

This is usually a LARGE effort and is only worth it if the item is unique and irreplaceable.

I wish you good luck in your search/repair efforts.

get a smooth shaft exactly the same size as the motor shaft.

get two strong steel plates with a hole that will fit the shaft

with 3 extra holes in alignment and three nuts and bolts

so you can make a bearing sandwich and compress the bearing

remove the sintered brass bearing from the motor.

place the shaft through the bearing. Install the three nuts and bolts to make the sandwich and tighten them until the bearing grips the shaft, but not so it siezes it and prevents turning. repeat with the other bearing. Reimpregnate the bearing with grease by heating them in grease. this will expel the air and on cooling they should draw it in. You can use moly grease or whatever.

Or you could get a small fan with bearings from an old USA made computer with ball bearings, often called muffin fans. They come in sizes 2", 3.25". 4.5" etc

An old trick that I have used successfully is to swish the motor in hot soapy water. Use a garden hose to rinse the motor throughly. Leave the motor in the sun for a couple days.

Use honey oil or 50 wt motor oil, and it unusually works fine.