Sleeve Bearing Metal

[lynnl]

In the process of dismantling a dead motor (elect. dryer) I noticed the sleeve bearings the shaft turned in were some kind of soft silvery metal. Looked too shiny to be lead, or what I've always thought babbit looked like. Both bearings were fed with oil soaked felt. Anyone know what metal that might have been? Actually it looked like aluminum. Is aluminum used for bearings?

[gamachinist]

It could have been aluminum.The main crankshaft bearing on aircooled VW's were aluminum.The crankshaft on most aircooled lawnmower engines run in an aluminum case and the rod has no inserts either.The splash lube doesn't provide that much lube to the mains.
I've seen some of the material you asked about and wondered myself if it was some grade of aluminum.
Robert.

[Evan]

Not likely aluminum. There are eight ASTM grades of babbitt alloys, four with lead and four lead free with tin. They have different appearances. It is undoubtedly one of those.

[yf]

Having scrapped a lot of motors, I've seen steel, aluminum, babbit, pot metal, composition brass, bronze, cast iron and probably other metals used as sleeve bearings.

See if a soldering iron will melt it. If not it may be aluminum.

Also try a magnet. (of course)

In cheap throw away motors, (appliances) I've seen mostly steel sleeves. They work amazingly well.

[Rotate]

"Aluminum Bronze" is use for for bearing, although the alloy that I've seen had more of a bronze colour.

Albert

[ulav8r]

Many dryer motors use a sintered steel bearing, dull gray when new. The shaft is usually case hardened by a process that also turns the shaft black. I work in a shop that makes about 80,000 shafts per day for appliance motors. Most use the steel bearings, some get ball bearings, others I don't know about. About half of our shafts are shippet to Mexico to be made into motors there. Many of those motors get shipped back to the US, others go to US owned plants in Mexico.

[wierdscience]

Sintered steel bearings I have seen many times it usually means cheapest of the cheap or disposable,babbit is generaly soft and grey in color,your automotive bearing shells are lined with a thin layer of babbit with copper underneath and a aluminum shell.Hang on to any babbit that stuff is still handy.

[gamachinist]

Not to be too pickey but the backing on all the automotive bearing shells I've seen so far except Air Cooled VW's are steel.
Robert.

[Evan]

Hang on to any babbit?????

Bad plan! If you mix lead containing babbit with lead free babbit, which contains tin, it will form a eutectic alloy of lead and tin (37/63) to the extent allowed by the available lead/tin. This is the same as radio solder, has no strength and melts at 187C, about half of babbit. The eutectic alloy will melt out of the babbit leaving a babbit "sponge" which will fail in short order. There is no way to tell by looking what kind of babbit you have and mixing them is fatal.

[This message has been edited by Evan (edited 06-04-2003).]

[wierdscience]

Never had an incounter with lead base in high speed bearing just the big low speed ones in container cranes,12"od shaft on the track rollers really low speed and high load,As for not telling them apart,you can't by sight or feel,but you can by specific gravity and melting point,a type "k"thermocouple and a Fluke meter is all you need and charts are avalible with specific details on the melting points.I once told a friend this and he said to me"well then how do you calibrate a thermcouple"?I said wipe it off and stick it under your armpit,If it tops out at 98.6 your safe.Anyway most of us who have use for it don't need a precise alloy unless its for a really high speed shaft such as a woodworking shaper.

[This message has been edited by wierdscience (edited 06-04-2003).]