Really enjoy your videos. I'm a hvac tech that has been working in residential for the past 6 years and have recently moved over to commercial work. Your videos are helping with the unfamiliar things i haven't had experience with yet.
I recall reading that sawdust used to be mixed with the bronze bits and then burned away after the bushing was formed. Thank you for your time, this was informative.
Very good video, perfect explanation. The oil will also help to expel any dirt as it oozes through. I got into looking this up because of a debate over lubricating graphite-sintered bronze bearings. Bronze and graphite are powdered, mixed, and sintered. These are the "permanently lubricated" fractional horsepower motor bearings. When the bearings fail, the motor is normally replaced or the whole machine just gets replaced with a newer model from Wal*Mart. My experience is that oil seems to make it worse - perhaps by catching abrasive dust, or perhaps because things are already way out of tolerance when the oil gets added. The interest is primary for restoring machines for which replacement parts are no longer available. Repairing a stand mixer from the 1940s, for example. Any tricks up your sleeve for those?
These are also known throughout history as oil light bearings. They're used extensively on old machines like old manual lathes. They work great and last forever under certain conditions but they're also used in areas where say a pulley belt system is cantilevered inherently causing a lot of pressure on the far end of the cantilever. This will destroy a standard ball bearing very rapidly it'll also destroy the oil light bearing but when it comes to precision machines oil light bearings are cheaper then matching high precision ball bearings
I heard that you cannot machine these bushings, because the machining would close the pores and prevent oil flow. Is that true? If so, is there a way to reopen the pores?
That is mostly true. The bearing is made by forcing the sintered bronze into the shape of the bearing. Any machining will cover most of the openings. No way to make it good. GFM
They are viable in motors up to at least 3300 RPM. The biggest problem with using these bearings is in low RPM motors because to get the oil into the bearing surface, there must be some heat from the bearing to draw the oil out. GFM
So what is the best type oil to use on these bearings that will "wick through" and lubricate well without getting "gummy"? Reason I ask is that I have a dehumidifier fan motor that uses this type of bearing, and the factory grease "gummed up", stalling the motor. I first tried cleaning the shaft, and re-lubing with thin "3-in-1 oil". This seemed to last a few weeks before the shaft started getting tight again, slowing the fan and squealing. This time I removed the bearings, flushed thoroughly with brake clean. and re-soaked the felts with Conklin "Rust Bomb" penetrating oil (even thinner than 3 in 1 oil ) that is supposed to "lubricate long after penetrating" and "resists evaporation". Jury is still out, but fan runs free for now. Probably the pores are clogged in the sintered brass and will starve it for lube...
The bearings are probably toast. When they get dry, the bearings (and maybe the shaft), are melted. The best oil I have used is the "zoom spout" oil. GFM
Soak the bushings in acetone overnight to clean them up. Afterward you'll need to re-impregnate the bronze with proper non-detergent 30wt oil. You can also use 3-in-one in the BLUE bottle that is made for electric motors. There are two ways of doing this. The proper way is to place the bushings in warm oil in a container where you can then pull a vacuum and the oil will be forced into the bushing. If you dont own such gear, you can heat the oil to about 180'f and let the bushings soak in it. Be careful not to set the place on fire if you use this method. Whatever you do, DON'T clean the bushings using abrasives. You'll end up 'smearing' (for lack of a better term) the bronze surface which closes off all those pores you want to put oil into. If you already did, you may be able to open up the surface using a fine emery paper. This doesn't always work depending on how closed off the surface had become due to improper cleaning.
Though i'm 5 years too late, the process that Oilite uses for their bushings involves heating the oil that the bushings are in, removing it from heat and then drawing a vacuum on the container. I use this method on bushings that i have soaked in acetone to get all the old gummed up oil out of. The bubbles come pouring out of the bushing. Here is my first attempt using not a proper vacuum pump, but a tonic bottle whose contents i previously mixed with Gin, but i used one of those hand vacuum pumps that are used to remove air from opened wine bottles. While this Macgyver method works, it takes longer than using the vacuum pump and proper container i have now. imgur.com/a/UNciMnT Looks cool though. Just not smart if that glass broke.
Explain Plug Graphite Bearings (bushings) and how they are not the same as these your show. Plug Graphite Bearings are not used as replacement and for slow linear movement only or you have to keep oil flowing to wash away graphite dust. Else they will fail.
Its a metallurgy thing. Bronze is made up of copper and tin with small amounts of other materials. The tin is a soft metal that absorbs contaminants. The copper is also somewhat soft. Harder metals like stainless or even aluminum will tend to damage the shaft. This is not a complete explanation by any means. GFM
Well no, oilite bronze has its place, just like needle bearings or even babbitt. Its all about selecting the right component for the job. There aren't any solutions in this world, that I have come across, that are always the right choice.
Really enjoy your videos. I'm a hvac tech that has been working in residential for the past 6 years and have recently moved over to commercial work. Your videos are helping with the unfamiliar things i haven't had experience with yet.
I looked this up because I had no idea what they actually were! Thank you!
This is really good, not many ppl do the vedio about these things... Good job..
Super nice and easily understood explanation!
I recall reading that sawdust used to be mixed with the bronze bits and then burned away after the bushing was formed.
Thank you for your time, this was informative.
johnny smith I guess it could be.
GFM
Very good video, perfect explanation. The oil will also help to expel any dirt as it oozes through.
I got into looking this up because of a debate over lubricating graphite-sintered bronze bearings. Bronze and graphite are powdered, mixed, and sintered. These are the "permanently lubricated" fractional horsepower motor bearings. When the bearings fail, the motor is normally replaced or the whole machine just gets replaced with a newer model from Wal*Mart. My experience is that oil seems to make it worse - perhaps by catching abrasive dust, or perhaps because things are already way out of tolerance when the oil gets added.
The interest is primary for restoring machines for which replacement parts are no longer available. Repairing a stand mixer from the 1940s, for example.
Any tricks up your sleeve for those?
had lots of dealings with them and didnt know this
thanks
Thanks, sharing this stuff is now my job, plus its fun.
GFM
grayfurnaceman Thank you GFM, I appreciate your explanation
These are also known throughout history as oil light bearings. They're used extensively on old machines like old manual lathes.
They work great and last forever under certain conditions but they're also used in areas where say a pulley belt system is cantilevered inherently causing a lot of pressure on the far end of the cantilever. This will destroy a standard ball bearing very rapidly it'll also destroy the oil light bearing but when it comes to precision machines oil light bearings are cheaper then matching high precision ball bearings
Thanks GFM....another informative one.
Great explanation, .... Thank You
I just had this idea of making a porous metal and soaking up the oil. I guess everythings already been done lol.
How are these made? Are they cold formed from wire? Powder press?
Very nicely explained man😊
thank you very much for this video!!!
How come some bronze looking bushings are magnetic?
I heard that you cannot machine these bushings, because the machining would close the pores and prevent oil flow. Is that true? If so, is there a way to reopen the pores?
That is mostly true. The bearing is made by forcing the sintered bronze into the shape of the bearing. Any machining will cover most of the openings. No way to make it good.
GFM
have question., Can this type of sintered bronze bearing use in electric motors that rotate at a speed of 1425 rpm, round per minute?
They are viable in motors up to at least 3300 RPM.
The biggest problem with using these bearings is in low RPM motors because to get the oil into the bearing surface, there must be some heat from the bearing to draw the oil out.
GFM
@@grayfurnaceman thank you Sir.
Couldve atleast show us dripping the oil on it to see it work
Just saved me watching the whole vid
Nicely explained
So what is the best type oil to use on these bearings that will "wick through" and lubricate well without getting "gummy"? Reason I ask is that I have a dehumidifier fan motor that uses this type of bearing, and the factory grease "gummed up", stalling the motor. I first tried cleaning the shaft, and re-lubing with thin "3-in-1 oil". This seemed to last a few weeks before the shaft started getting tight again, slowing the fan and squealing. This time I removed the bearings, flushed thoroughly with brake clean. and re-soaked the felts with Conklin "Rust Bomb" penetrating oil (even thinner than 3 in 1 oil ) that is supposed to "lubricate long after penetrating" and "resists evaporation". Jury is still out, but fan runs free for now. Probably the pores are clogged in the sintered brass and will starve it for lube...
The bearings are probably toast. When they get dry, the bearings (and maybe the shaft), are melted. The best oil I have used is the "zoom spout" oil.
GFM
Soak the bushings in acetone overnight to clean them up. Afterward you'll need to re-impregnate the bronze with proper non-detergent 30wt oil. You can also use 3-in-one in the BLUE bottle that is made for electric motors. There are two ways of doing this. The proper way is to place the bushings in warm oil in a container where you can then pull a vacuum and the oil will be forced into the bushing. If you dont own such gear, you can heat the oil to about 180'f and let the bushings soak in it. Be careful not to set the place on fire if you use this method.
Whatever you do, DON'T clean the bushings using abrasives. You'll end up 'smearing' (for lack of a better term) the bronze surface which closes off all those pores you want to put oil into. If you already did, you may be able to open up the surface using a fine emery paper. This doesn't always work depending on how closed off the surface had become due to improper cleaning.
very informative. thank you.
What is the "bronze" what does it contain that is not copper. Same or different for each manufactorer.
It is mostly copper with some tin. Different manufacturers use assorted other metals for different applications.
GFM
I'm afraid not. That one would have to go to a bearing manufacturer.
GFM
thanks GFM
Very good overview!
do you know anything about the process of vacuum injection of lubricant into these types of bearings? How is that done?
Though i'm 5 years too late, the process that Oilite uses for their bushings involves heating the oil that the bushings are in, removing it from heat and then drawing a vacuum on the container. I use this method on bushings that i have soaked in acetone to get all the old gummed up oil out of. The bubbles come pouring out of the bushing. Here is my first attempt using not a proper vacuum pump, but a tonic bottle whose contents i previously mixed with Gin, but i used one of those hand vacuum pumps that are used to remove air from opened wine bottles. While this Macgyver method works, it takes longer than using the vacuum pump and proper container i have now.
imgur.com/a/UNciMnT
Looks cool though. Just not smart if that glass broke.
Thank you
Can you melt them down into bronze ingots?
You could but why?
GFM
Hi Gray. Question, do you know the final density of this sintered material? Thank you for the informative video!
I have no idea. You might try a manufacturer.
GFM
Explain Plug Graphite Bearings (bushings) and how they are not the same as these your show. Plug Graphite Bearings are not used as replacement and for slow linear movement only or you have to keep oil flowing to wash away graphite dust. Else they will fail.
thanks gfm
Are these bushings machinable?
Yep, annoying though
why should bronze ? why not stainless steel or etc ?
Its a metallurgy thing. Bronze is made up of copper and tin with small amounts of other materials. The tin is a soft metal that absorbs contaminants. The copper is also somewhat soft. Harder metals like stainless or even aluminum will tend to damage the shaft. This is not a complete explanation by any means.
GFM
Thanks for the support.
GFM
EXCELLENT
Fred Stebbing Thanks for the support.
GFM
Thx :)
Alex Benedek Welcome.
GFM
Man, these bushing suck - they make a lot of noise after a short time... Ball or needle is the way to go
Well no, oilite bronze has its place, just like needle bearings or even babbitt. Its all about selecting the right component for the job. There aren't any solutions in this world, that I have come across, that are always the right choice.