Lubricating electric motors

Awl--
I have observed several methods for motor lubrication, and have a Q or two.
1. Grease/zerk fittings: How do you know when you've pumped enough grease in?
At what intervals? Best grease for this app? I've thought of re-stuffing the cartridge tubes w/ grease from cans, if I can't find the best grease already in a a tube. Are grease fittings a sign of an older motor? Are all modern motors "permanently lubed" bearings? Is there really such a thing as permantly lubed??
2. set screw where a grease fitting would seem to go. Put a zerk there? Squirt in oil of some kind? 3 in 1? Other? What's the diff between this set screw style and a regular oil cup?
My favorite lube system is the old dancing ring/grooved bronze sleeeve bearing in an oil bath. Really neat to watch--better than most TV.
TIA. -- Mr. P.V.'d formerly Droll Troll
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Not sure how you tell. IMO, if it is an old motor, it'd be a good idea to open it up and wash the old, hardened, grease out of the bearing area and apply new grease by hand. Then regrease sparingly, a squirt or two should suffice. I overgreased my old 7 1/2 HP Wagner motor once and it caused it to run hot.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I got perhaps 12 years service from a 1hp motor with grease bearings running in a very severe grinding enviornment. Once the bearings had worn enough to develop some slop I replaced them with sealed permanently lubed ones for about $14 and removed the zerks. My experience has taught me that you destroy far more electric motors through overlubrication than from underlubrication, especially sleeve types. If you have time and patience open up the motor and give it a good cleaning.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Really P.V., you must get out more!
Tom
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Tom Miller wrote:

Or get cable.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

GENERALLY, motors with screw plugs have sealed bearings. The end caps are used with sealed and lubable. Some of the ones with zerks specify OIL, not grease. Use an oil gun like on your Myford lathe. *** Free account sponsored by SecureIX.com *** *** Encrypt your Internet usage with a free VPN account from http://www.SecureIX.com ***
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
<clare at snyder.on.ca> wrote in message

This makes a lot of sense. I will make sure to call the motor mfr's and see what's up. But I never heard/saw of an oil gun--no Myford lathe, I spose. :). So I looked in MSC. Where your std. grease gun is $10-20, an oil gun is $105!! goodgawd.... Any improvisations I can make, if I indeed need an oil gun? -- Mr. P.V.'d formerly Droll Troll

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
message

On a more serious note, most modern electric motors ( made in the last 15 years) use sealed ball bearings in sizes up to about 25 Kw. In my experience you are better not to try to lubricate them at all. At a brewery where I was engineering manager, we had about 100 small motors up to about 5 Kw in the packaging department. They went largely unlubricated for years at a time. I have ,on the other hand, had motors fail in a few weeks due to the over dilligence of one of our Gilbert Island greasers at another plant. I fixed that problem by getting him to give it 2 shots of grease on his birthday every year.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 24 Feb 2006 13:14:18 +1100, "Tom Miller"

He wasn't born on Feb 29, I assume. *** Free account sponsored by SecureIX.com *** *** Encrypt your Internet usage with a free VPN account from http://www.SecureIX.com ***
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Nope. I checked that!
Tom
<clare at snyder.on.ca> wrote in message

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Proctologically Violated wrote:

Best to RTFM. The motor manufacturers probably had a pamphlet that gave their recommendations. To the best of my recollection, GE recommended greasing their motors with grease every year if the motor was run 80 hours a week or more. And every three years if only run 40 hours a week.
I think you remove the plug below the shaft and pump in grease in the zerk until grease comes out the hole below the shaft. Should be one or two pumps on a grease gun.
Dan
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.