Greasing motor bearings

[GeoLane at PTD dot NET]

With all the talk of excess grease hurting motor bearings, I have been
reluctant to add grease to a motor that probably could use some. The
motor for my lathe has screws where the grease fitting would go , but
I haven't greased it in the 30 years I've had it. I probably ought to
do that. What grease and how much?

RWL

[Bill Noble]

are you sure that putting grease in the screw holes will reach the bearings?
Do you have a lathe manual you could check? sometimes the same castings
support ball bearings and busings, and the holes are covered over for ball
bearings - sometimes they are there so you can install a grease fitting and
grease - your manual may well provide useful guidance

<GeoLane at PTD dot NET> wrote in message
news:e3u7r590p16foedqp...@4ax.com...

[sta...@prolynx.com]

On Mar 31, 7:39 pm, GeoLane at PTD dot NET <GeoLane at PTD dot NET>
wrote:

Are you sure it's a ball-bearing motor? Bushings take oil, not
grease. And are you sure it's got open ball-bearings if it IS ball-
bearing? If they're double-shielded numbers, there's no entrance for
grease. As far as what to use, auto wheel-bearing grease will work.
If it has bleed holes for excess grease, pump it in until you get the
old stuff out. What you want to do is get the old soap carrier out
and replace it with the new stuff. If you start pumping, though, and
there's no internal grease seal, you could get grease inside, which
wouldn't help with running.

Safest way would be to disassemble the motor, manually pack the
bearings and reassemble. You could vacuum out the crap that
accumulates that way, too. Or if you've got it down that far, replace
the bearings.

Stan

[Ignoramus23298]

On 2010-04-01, sta...@prolynx.com <sta...@prolynx.com> wrote:
> Safest way would be to disassemble the motor, manually pack the
> bearings and reassemble. You could vacuum out the crap that
> accumulates that way, too. Or if you've got it down that far, replace
> the bearings.

I agree with Stan 100%. Swapping bearings on a motor is easy and
usually inexpensive. You can get great quality permalube bearings that
will essentially never need any attention, at least in HSM setting.

i

[GeoLane at PTD dot NET]

On Wed, 31 Mar 2010 20:28:29 -0700, "Bill Noble"
<nob...@nowhere.invalid> wrote:

>are you sure that putting grease in the screw holes will reach the bearings?
>Do you have a lathe manual you could check? sometimes the same castings
>support ball bearings and busings, and the holes are covered over for ball
>bearings - sometimes they are there so you can install a grease fitting and
>grease - your manual may well provide useful guidance

This was a motor I added after I got the lathe, so it's not referenced
in the owner's manual. The original motor was 3 phase, and 30 years
the ease of making a rotary phase converter was a big secret, so I
just replaced it with a single phase motor.

RWL

[GeoLane at PTD dot NET]

OK. Do nothing it is. They aren't making any noise now and if
bearings are cheap, it would just be easier to replace them than the
hassle of pulling the motor now for preventive maintenance. I plan
to sell this machine when I have the rebuild of the varispeed drive
completed on my new Clausing.

RWL

[John]

If the motor was designed to be periodically greased it will have a
threaded hole, usually plugged, both top and bottom of the bearing
housing. To lube one you removed both the top and the bottom plug;
screwed a grease fitting in the top hole and pumped grease into the
bearing until clean grease came out the bottom. Removed the grease
fitting and reinstalled both plugs.

It was in every makers instructions and particularly the warning to
remove the bottom plug and NOT pressurize the bearing housing and
force grease through the seal and into the body of the motor.

Cheers,

John D.
(jdslocombatgmail)