Oil for DC motor question

[MrSmithers]

I hope this is an ok area to post this question. Here’s an old electric motor and there’s 2 spots that are stamped “oil”. One on the top and one on the side. Is this two separate areas to put oil in or is it like add oil to top till it comes out the side?
Any help is appreciated. Sorry if it’s wrong area in forum

 

[waross]

put oil in or is it like add oil to top till it comes out the side

Best guess.
That looks like a reduction gear mated to the motor.
Top plug to fill, and the side plug to check the level may be appropriate for a reduction gear.
But, this is free advice from a stranger on the internet.

 

[3DDave]

The hexagonal one looks like a breather fitting inserted into a fill port, being the larger size.
The round cap looks to seal the chamber with a smaller opening.

I'll double the price waross put on this and say that, for free from someone you have never met and who hasn't seen the motor in person, the top one is to fill it until it runs out the side one.

If you drained it, how much came out and was it cloudy or darker than expected? If it looks good, put it back.

The trickier question is what sort of oil is required. I have a 40 year old can labeled "electric motor oil" for home projects, but no idea what is in it.

It appears to be a product of this company, Merkle-Korff:

After the war, two very significant developments changed the course of the Company. Automatic vending machines became widely accepted in the United States and these mechanical servants required several small motors to dispense ingredients and end products to customers. Volume production of gearmotors began in that period and gradually became the main product of the Company. This first lineup was called the “Flexo-Action” line. Photocopy machines, automatic ice makers for home refrigerators and even gambling equipment were soon major applications for gearmotors and sixty-five years later the Appliance, Business Equipment and Vending Industries are still high volume users of the small gearmotor.

They are now part of Nidec, but are still in business. I'm sure a tech support engineer would be delighted to hear about and help with the antique motor. I see you made a reddit post that this is from an old Coca-Cola machine. Fun stuff.

Tel: 847.439.3760
General Email: mksales@nidec-mk.com
Customer Service Email: customer.service@nidec-mk.com

 

[Gr8blu]

Third time's the charm. A free guess, just like the first two.

System is what would be called a gear motor in today's terminology (i.e. a motor directly connected permanently to a specific gear and sold as a complete unit).
Top opening has a hex breather plug/fill fitting. Side opening has a smaller round (star cut) drain plug.
Motor is a 2-pole AC motor, designed to operate at 115 V on a 60 Hz system.
Nominal operating speed is in the neighborhood of 3280 rpm (motor side) to give 20 rpm on the exposed star coupling which should mesh with some kind of chain drive.

 

[MrSmithers]

The hexagonal one looks like a breather fitting inserted into a fill port, being the larger size.
The round cap looks to seal the chamber with a smaller opening.

I'll double the price waross put on this and say that, for free from someone you have never met and who hasn't seen the motor in person, the top one is to fill it until it runs out the side one.

If you drained it, how much came out and was it cloudy or darker than expected? If it looks good, put it back.

The trickier question is what sort of oil is required. I have a 40 year old can labeled "electric motor oil" for home projects, but no idea what is in it.

It appears to be a product of this company, Merkle-Korff:



They are now part of Nidec, but are still in business. I'm sure a tech support engineer would be delighted to hear about and help with the antique motor. I see you made a reddit post that this is from an old Coca-Cola machine. Fun stuff.

Tel: 847.439.3760
General Email: mksales@nidec-mk.com
Customer Service Email: customer.service@nidec-mk.com

Yah I did but no response. Thanks for the input!
Maybe I will try the company. I did try to add oil and have it come out but it was taking so much I got worried. I understand regular maint is to add about a tablespoon periodically.
I don’t think there was any left n it cause nothing came out at all. That being said I don’t know how much it holds

 

[MrSmithers]

Third time's the charm. A free guess, just like the first two.

System is what would be called a gear motor in today's terminology (i.e. a motor directly connected permanently to a specific gear and sold as a complete unit).
Top opening has a hex breather plug/fill fitting. Side opening has a smaller round (star cut) drain plug.
Motor is a 2-pole AC motor, designed to operate at 115 V on a 60 Hz system.
Nominal operating speed is in the neighborhood of 3280 rpm (motor side) to give 20 rpm on the exposed star coupling which should mesh with some kind of chain drive.

So you think it’s a full from top till it drains from side?

 

[LittleInch]

Can you give us a picture of the whole assembly?

My gues sis that the whole chamber is flooded up to half way which gives you some idea of what volume you have, but the poil you need to use is probaly minerla oil or "machine oil" - very thin.

 

[waross]

but the poil you need to use is probaly minerla oil or "machine oil" - very thin.

Personally I would go with SAE 80 to SAE 140 for gear lubrication and less leaking.
Who is correct, LittleInch or myself?
Flip a coin.
But that's free advice on the internet for you. grin

 

[LittleInch]

Or automotive gearbox oil?

 

[MrSmithers]

Or automotive gearbox oil?

This is what I was using

 

[MrSmithers]

Also here’s some views of inside the holes

 

[MrSmithers]

Here’s a video of it all
View attachment IMG_3312.mov

 

[Gr8blu]

In a modern machine, chances are good that the motor bearings are grease lubricated and sealed so that the gear oil doesn't affect the motor bearing. Use a heavier weight oil for the gear - (turbine grade) mineral oil would be for motor bearings, if they were oil lubricated.

In something like this? Your guess is as good as anyone else's.

 

[MrSmithers]

In a modern machine, chances are good that the motor bearings are grease lubricated and sealed so that the gear oil doesn't affect the motor bearing. Use a heavier weight oil for the gear - (turbine grade) mineral oil would be for motor bearings, if they were oil lubricated.

In something like this? Your guess is as good as anyone else's.

And the gear section is the darker gray side on left I presume?

 

[MrSmithers]

Hey all
I decided to take the second top bolt off and the cover came right off. Maybe these views will help. You can see the top two holes in first pic
It does look like the gears are oiled separate from other end

 

[MintJulep]

What's this gearmotor used for?

Continuous or intermittent?

Probably that 3 in 1 oil is fine for the gears. Certainly better than nothing.

The motor might have oil impregnated bronze bushings as bearings. They might enjoy a drop or two of oil.

 

[MrSmithers]

What's this gearmotor used for?

Continuous or intermittent?

Probably that 3 in 1 oil is fine for the gears. Certainly better than nothing.

The motor might have oil impregnated bronze bushings as bearings. They might enjoy a drop or two of oil.

It’s for a vending machine so intermittent

 

[Lacquit]

oil is usually filled through the top hole until it reaches the side level, which serves as a check level. It is important to use the recommended oil type to avoid damage to the engine.

 

[dwillem317]

I have the same issue with mine that came from my refrigerator here. What would be the recommended oil type? I bought it a while ago dont have the manuel