I have a couple of 7.5 hp 3 phase 184 frame motors. Both have zerk fittings. I
don't normally see zerk fittings on motors fitted with ball bearings, which I
assume these motors have. I'm wondering if I should pump oil in there or grease
- anyone know? One is a Baldor motor but the model is no longer referenced on
the Baldor Web page, or I'd just look it up there. The other is an older US-made
motor, don't remember the manufacturer, but I highly doubt they're still around,
probably 1970s vintage.

GWE

Not saying I'm right here, but I have a number of large motors with zerks. I
give them all one shot/zerk every year. So far, the world hasn't crumbled.

Karl

Sorry, insert lithium grease.

Karl

"Karl Townsend" remove .NOT wrote in
message ews.com...
Not saying I'm right here, but I have a number of large motors with zerks.
I give them all one shot/zerk every year. So far, the world hasn't
crumbled.

Karl

Most older motors had zerks on them. They should be greased annually
with two squirts of the grease gun, according to most manufacturers.
The danger is in over-greasing. It blows out the seals and leaks grease
into the motor and leads to bearing failure. Modern motors use sealed
bearings that require no lube for the life of the motor, then you just
install a new set.
Bugs

Grant Erwin wrote:

I have a couple of 7.5 hp 3 phase 184 frame motors. Both have zerk fittings. I
don't normally see zerk fittings on motors fitted with ball bearings, which I
assume these motors have. I'm wondering if I should pump oil in there or grease
- anyone know? One is a Baldor motor but the model is no longer referenced on
the Baldor Web page, or I'd just look it up there. The other is an older US-made
motor, don't remember the manufacturer, but I highly doubt they're still around,
probably 1970s vintage.

GWE

Before you pump grease in them, look on the other side from the fitting
for a plug. Pull the plug out first and only pump a couple of pumps
into the fitting. Too much grease and it will go into the motor if you
dont have the other plug out.

John

"Bugs" wrote in message
ups.com...
Most older motors had zerks on them. They should be greased annually
with two squirts of the grease gun, according to most manufacturers.
The danger is in over-greasing. It blows out the seals and leaks grease
into the motor and leads to bearing failure. Modern motors use sealed
bearings that require no lube for the life of the motor, then you just
install a new set.
Bugs


Allot of manufacturers STILL have zerks on their motors. I install and
service commercial HVAC equipment and see grease zerks on new equipment all
the time, so it is not a modern thing!
Greg

Ahh! Reminds me of my Navy Life. "To grease or not to grease?? That is the
question."

Large motor frames aways seemed to have a grease passage into the bearing
seat area. However, the mfg would only install a zerk if the motor had open
bearings (common in motors 40 years ago). Later, as sealed bearings became
common, they put plugs in the threaded openings.

Over time many/most of the navy motors went into for cleaning and overhaul.
Sealed bearing replaced any open bearings still installed and the service
facility pluged the grease passage to prevent damage to the sealed bearing
and motor by pumping in grease.

However, the maintanance cards still called for greasing the motor every
year or so. So the sailor would reinstall the grease zerks and fill the
motor with much un-needed grease.

Bottom line, most large frame motors will have grease passage, however the
only way to determine if it has open bearings would be to pull the need
bells and see what type of bearing it has. No need to remove the bearing
since you should be able to see the seal on the exposed side of the bearing.


--
My experience and opinion, FWIW


Steve (CWO2 USNavy ret.)

On Fri, 16 Dec 2005 22:11:02 -0800, Grant Erwin
wrote:

I have a couple of 7.5 hp 3 phase 184 frame motors. Both have zerk fittings. I
don't normally see zerk fittings on motors fitted with ball bearings, which I
assume these motors have. I'm wondering if I should pump oil in there or grease
- anyone know? One is a Baldor motor but the model is no longer referenced on
the Baldor Web page, or I'd just look it up there. The other is an older US-made
motor, don't remember the manufacturer, but I highly doubt they're still around,
probably 1970s vintage.


As stated care must be taken to not over grease. I have seen
recommendations to remove the pipe plug opposite the grease fitting to
allow the excess to get out.

Wayne Cook
Shamrock, TX
http://members.dslextreme.com/users/waynecook/index.htm

If the motor has zerks, it should have drain plugs on the bottom of the
bearing housings. You should remove the drain plugs and pump in a good
quality grease thru the zerks until you get some out flow from the drains.
Leaving the drains open, start the motor and run until the bearing housing
temp stabilizes. Some additional grease will flow out. Then you can plug
the drains. You are now set for several years of operation if the bearings
are good.

The above assumes your motors have internal bearing caps that close off the
bearing cavities from the stator housing. They prevent grease from getting
into the rotor/stator area if the drains are open during lubrication. Cheap
motors usually do not have caps or zerks. YMMV.

Randy



"Grant Erwin" wrote in message
...
I have a couple of 7.5 hp 3 phase 184 frame motors. Both have zerk
fittings. I don't normally see zerk fittings on motors fitted with ball
bearings, which I assume these motors have. I'm wondering if I should pump
oil in there or grease - anyone know? One is a Baldor motor but the model
is no longer referenced on the Baldor Web page, or I'd just look it up
there. The other is an older US-made motor, don't remember the
manufacturer, but I highly doubt they're still around, probably 1970s
vintage.

GWE

Gene says:

There is no simple answer, here. The manufacturer installed a zerk on
the open side of the sealed or shielded bearing and expected you to
grease it.

Around 1984 at the company I worked at someone in Service or
Engineering contacted Lincoln Motors engineering dept. and asked
exactly how much grease to pump into their motors (in response to a
customer's question about the lack of information in the literature
received with their motor) and was told the only reason the zerks were
there was because the bearings were lubricated after installation in
the factory and it was cheaper to leave the zerks in than replace them
with plugs.

Damn dumb long sentence; sorry.

They recommended never lubricating. Ten years X 5 days a week X 8
hours a day of moderate use would be the average service life of the 1
1/2 to 5 horsepower motors we were using at the time. The problems
that arose were generally with the insulation, not the bearings.

dennis
in nca

Ain't no big deal to replace greased bearings with permanently lubed or
even sealed ones.
What you don't want is grease on the motor windings.
If you split the motor then while you are in there clean everything up
and dress the start contacts too.
I never got around to spraying a coat of winding varnish on any of my
refurbish jobs but I hear it's not a bad idea.
Setting new bearings on 60-100 w light bulbs to expand them works well
for cheap.
Half of what I know I learned picking brains in this newsgroup.

On 17 Dec 2005 21:47:46 -0800, "rigger" wrote:

Gene says:

There is no simple answer, here. The manufacturer installed a zerk on
the open side of the sealed or shielded bearing and expected you to
grease it.

Around 1984 at the company I worked at someone in Service or
Engineering contacted Lincoln Motors engineering dept. and asked
exactly how much grease to pump into their motors (in response to a
customer's question about the lack of information in the literature
received with their motor) and was told the only reason the zerks were
there was because the bearings were lubricated after installation in
the factory and it was cheaper to leave the zerks in than replace them
with plugs.

Damn dumb long sentence; sorry.

They recommended never lubricating. Ten years X 5 days a week X 8
hours a day of moderate use would be the average service life of the 1
1/2 to 5 horsepower motors we were using at the time. The problems
that arose were generally with the insulation, not the bearings.

dennis
in nca


We used to grease MG sets, while running, just once a year, and listen
VERY carefully as you pump for the SLIGHTEST noise change. That's
enough.

Brian Lawson,
Bothwell, Ontario.

Well, 100% of the responders indicated the zerk fittings are for grease, no
votes for oil.

I am very pleased with the performance of my latest $20 7.5 hp motor. I
scrounged it awhile back dirt cheap because it had a badge on it that said it
was a 50Hz motor and the seller thought you couldn't use it on 60Hz power. I
told him, but he didn't believe me and laughed at me. I figured I'd done enough
to meet a reasonable moral standard and bought it. It runs amazingly quiet and
smoothly for a 3450 rpm motor. (By the way, after I got it home I discovered it
has another nameplate for 60Hz power, it's simply one rated for either.)

It replaced the one which came off the old 16" chop saw I'm rebuilding. That
motor had the worst bearings I've ever heard. I put new spindle bearings in the
saw too, and the reduction in noise when spun up and not cutting is simply
enormous. I'm going to tear down the old motor and see what kind of bearings are
in it. I suspect they're open sided ball bearings, but they might be sleeve
bearings, which are said to run quieter.

I'm having fun rebuilding this old chop saw. I'll see how it works for me and if
I like it I'll keep it, else I'll either sell it or donate it to the local
welding school.

GWE

At work there was a motor generator and the motor ( GE ) had Zerk
fitting. As I remember GE recommended greasing every three years if
the motor was run 16 hours a day , five days a week. Otherwise they
recommended every ten years.

Naturally this motor was run only a couple of hours / month and the PM
called for annual greasing. There was no way to schedule the greasing
less often than annually.


Dan

On 18 Dec 2005 18:01:35 -0800, "
wrote:

At work there was a motor generator and the motor ( GE ) had Zerk
fitting. As I remember GE recommended greasing every three years if
the motor was run 16 hours a day , five days a week. Otherwise they
recommended every ten years.

Naturally this motor was run only a couple of hours / month and the PM
called for annual greasing. There was no way to schedule the greasing
less often than annually.

Put a sticker by each fitting "Grease only if the year ends in 5"
Gerry :-)}
London, Canada