Hello everyone,

I have a vintage NOS Series DC electric motor with me. The motor shaft quite stiff and when powered up from an 18V laptop power supply it does spin, but the rpm is quite low as its rated for 2400rpm. It's an 18VDC, Model: YY1W027 from Universal Electric Co. On the label of the motor (see attachment please) it says oil the motor every three months with No. 20 Auto Oil.

I have some Automatic Transmission Fluid with me and also some sewing machine oil from grapes brand. If I remember it must be a Grade 15 as per manufacturer when I brought it long ago. Can any of these be used to lubricate the motor? If yes which of them would be better.

Thanks in advance,
R

 

if you did not meant it by default , there is no point to lubricate the motor but the bearings of - so you'd go for this

https://www.google.com/search?q=electro-mechanics+bearing+grease

i have only maintained the fan bearigns - flushed with WD 40 then silica then lubed with grease - (donno if it's a correct sequence)

 

What is the composition of the bearings, if sintered bronze, you do not want to use a grease based lube, this will make matters worse.
The bearing cover shows a oil spout so thin oil is necessary, ATF can be used in place of a recommended, but also the #15 you show should be OK.
If it is stiff to turn, it would be better to take the end covers off and soak and lube them that way until they spin freely.
Max.

 

if you did not meant it by default , there is no point to lubricate the motor but the bearings of - so you'd go for this

https://www.google.com/search?q=electro-mechanics+bearing+grease

i have only maintained the fan bearigns - flushed with WD 40 then silica then lubed with grease - (donno if it's a correct sequence)

I did clean the bushings of the motor and the armature to remove the old crusty lubricant or grease. It was what that made the motor so difficult to spin and very stiff. I cleaned it off with WD-40 and then with Solder Seal Gunk Silicone oil.

I didn't want to use any grease as I'm not very sure about the type of grease or if it's recommended for this motor. On the motor label they have mentioned only about No.20 SAE Oil.

 

What is the composition of the bearings, if sintered bronze, you do not want to use a grease based lube, this will make matters worse.
The bearing cover shows a oil spout so thin oil is necessary, ATF can be used in place of a recommended, but also the #15 you show should be OK.
If it is stiff to turn, it would be better to take the end covers off and soak and lube them that way until they spin freely.
Max.

Hello Max,
This motor does not have ball bearings, instead it's bushings I see. I've attached a few more picture of the inside of the motor in the original post for a reference. Yes, I don't plan to use grease as I was worried about the grease aching any issues.

I was skeptical about ATF because its a thinner oil and its lubrication effect may not last very long is my concern. The sewing oil is more viscous though.

It was stiff as the old lubricant around the bottom of the armature was crusty and dried up there. I had to clean it off completely. I think I'll go ahead with the sewing oil then. BTW can I use compressor mineral oil? I mean the ones in R-22 type compressors?

 

It sounds like you have sintered bronze (porous) bearings, once they become saturated, i.e. non-porous, they really need replacing, the other way is to leave them to soak in Kerosene for a couple of days then blow them out with compressed air.
Then soak in the correct or similar SAE oil.
Check for wear also.
Max.

 

I would use they sewing machine oil. Was there not a felt pad that acted as a resivoir?

 

Frankly, I think AFT ATF (modern) is probably pretty good: https://team.valvoline.com/diy/how/specs-choosing-right-atf-your-vehicle And definitely better than WD-40 or 3-in-1.

 

Frankly, I think AFT

ATF?
They use this in machine gearboxes now in some cases. It is an often under rated lube.
Max.

 

I am not only a left-handed dyslexic, but I need a new keyboard. The letters are worn off half the keys. So errors from my Columbus school of typing go undetected. Error fixed.

BTW, my big lathe (British Smart and Brown 10" circa 1966) uses plain spindle bearings. Getting spindle oil in small amounts is difficult. I am thinking of switching to ATF for it.

 

It sounds like you have sintered bronze (porous) bearings, once they become saturated, i.e. non-porous, they really need replacing, the other way is to leave them to soak in Kerosene for a couple of days then blow them out with compressed air.
Then soak in the correct or similar SAE oil.
Check for wear also.
Max.

The bearing don't have wear since the motor was still in original box and was never used until now by me. It was an NOS piece.

 

I would use they sewing machine oil. Was there not a felt pad that acted as a resivoir?

Yes, I went ahead with the sewing oil for now. That's right there is a felt pad on the top and bottom of the motor casing. After oiling it and now the motor runs pretty smooth. I didn't go aheads with ATF as I felt the oil was too thin.

 

BTW, my big lathe (British Smart and Brown 10" circa 1966) uses plain spindle bearings. Getting spindle oil in small amounts is difficult. I am thinking of switching to ATF for it.

I have the same problem with my machines too, no one sells in small amounts(under 5gallons) I've gone to using chain saw bar oil as way lube and in the gear box of my lathe. It's made to be a high pressure lube and is about the same viscosity as the stuff they used at work. 10 plus years now and no problems.

 

They use this in machine gearboxes now in some cases. It is an often under rated lube.

Also used in manual transmissions and rear axles in cars since early to middle 1990s.

 

ATF is the superior choice because it contains high levels of Detergents/Dispersants and High-Pressure additives,
this will eventually clean out the old goo in the bearings and keep them clean.
"Sewing Machine Oil", and similar oils, such as "3-in-1" oil,
are made of garbage that the Oil Refineries can't sell for any other purpose.
They eventually turn into useless "goo", especially when heated.
On the other hand, ATF is designed to run at temps around ~100C, continuously.
ATF also contains "Viscosity Modifiers" which help to maintain it's Viscosity at high temps.

 

if you did not meant it by default , there is no point to lubricate the motor but the bearings of - so you'd go for this

https://www.google.com/search?q=electro-mechanics+bearing+grease

i have only maintained the fan bearigns - flushed with WD 40 then silica then lubed with grease - (donno if it's a correct sequence)

silicone.... silica's an abrasive

 

Until recently I owned a couple of XLO CNC-retro-fitted mills, when I spoke to Excello about a spindle G.B. issue, they told me they had gone over to recommending ATF in the G.B. now.
Max.

 

ATF is the superior choice because it contains high levels of Detergents/Dispersants and High-Pressure additives,
this will eventually clean out the old goo in the bearings and keep them clean.
"Sewing Machine Oil", and similar oils, such as "3-in-1" oil,
are made of garbage that the Oil Refineries can't sell for any other purpose.
They eventually turn into useless "goo", especially when heated.
On the other hand, ATF is designed to run at temps around ~100C, continuously.
ATF also contains "Viscosity Modifiers" which help to maintain it's Viscosity at high temps.

So, you are saying that ATF is better than the machine oil. I thought that the lesser viscosity of the ATF made it less suitable in open lubricated systems as the oil would drain away and adhere less to the surface. I mean an ATF fluid is generally used in a transmission of a car that is sealed unit. While in case of engine oil its more viscous and sticky so that the engine oil adheres better to the piston etc where its splashed to the parts and not soaked in the oil.

If ATF is better then I'll open up the motor again and clean off the old oil and then re-oil it with ATF.