goofy motor bearings

I just tore down a early 1960s 3/4 HP 3 phase motor to examine the insides. It's from a drill press and has grease fittings on it, even though it's just a 56 frame motor with a 5/8" shaft. There's nothing special about the motor other than it has a factory paint job that matches the rest of the machine.

Anyways, the thing was full of grease, yet had shielded (6203zz I think) Nachi made in Japan bearings installed. They seemed too new to be original,and why the thing was packed with grease baffles me. Nothing looks modified in any way.

The only thing that would make even a lick of sense is there were unshielded bearings in there originally and that's why there were grease ports. Why the thing was pumped full of grease later is a mystery.

Anybody seen anything like this before?

Reply to
Cydrome Leader
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That's better than no lube ever, like some of the machines I bought used. The trade school students had broken most of the oil cups off my lathe.

--jsw

Reply to
Jim Wilkins

On 06/08/2016 11:13 AM, Cydrome Leader wrote: ...

If you got a piece of gear with grease zerks, wouldn't _you_ grease it on the presumption they were there for a reason?

Sure, happens not frequently but on occasion. Are the bearings really sealed or just shielded in the latter case there is still a reason.

Reply to
dpb

They're double shielded, the sealed for life throw away type. Only the larger bearing for the variable speed drive (a sheave that slides up and down a shaft) has a removable seal kit.

Was there a transition in the industrial motor world where they still drilled and tapped grease ports in motor housings but just installed ball bearings instead?

Reply to
Cydrome Leader

Buda-bing!

And a gold plated no prize for our contestant!

-- pyotr filipivich "With Age comes Wisdom. Although more often, Age travels alone."

Reply to
pyotr filipivich

Cydrome Leader on Wed, 8 Jun 2016 17:00:46

+0000 (UTC) typed >> >> ...

Or, just as likely, the original bearings were replaced with sealed ones. And with the zerks in place, someone thoughtfully greased the bearings. Whether they needed it or not.

tschus pyotr

-- pyotr filipivich "With Age comes Wisdom. Although more often, Age travels alone."

Reply to
pyotr filipivich

Not if it is an old Bridgeport mill, you oil those grease fittings.....

MikeB

Reply to
BQ340

I've done it myself many times. I should have removed and plugged the zerks but was too lazy.

Reply to
Tom Gardner

So what used to be inside this motor? The same bearings, but with no shield, and tons of grease? What the standard pratice for fractional HP motors 50+ years ago?

Reply to
Cydrome Leader

I've seen double sealed bearings installed in place of single sealed - the grease fitting is on the "unsealed" side. Does no good with double sealed bearings and can pop the outer seal off single sealed bearings in some cases.

Reply to
clare

shit like this happens all the time

welcome to corporate stupidity in action

They did not grease the motor when it had plain or unshielded bearings

Then they replaced them with shielded bearings and having been burned by bearing failure, introduced a greasing schedule

It is easy to make fun of such pe> I just tore down a early 1960s 3/4 HP 3 phase motor to examine the

Reply to
Ignoramus27719

It is not always corporate stupidity. Where I use to work there was a moto r that drove a 800 cycle generator. The 800 cycles was used during missile testing and was needed about two or three hours a week. The motor had gr easeable bearings and as I remember the manufacturer recommended a couple o f shots of grease every five years when the motor was used 16 hours a day. The PM schedule could be scheduled for daily, weekly, monthly , every thre e months , twice a year , and once a year. So what would you do? Grease t he motor once a year? Or not ever grease the motor?

Dan

Reply to
dcaster

And the broken nipples had been left in the holes? That sounds like the machines I used in 8th grade metalshop.

Reply to
Larry Jaques

It is not always corporate stupidity. Where I use to work there was a motor that drove a 800 cycle generator. The 800 cycles was used during missile testing and was needed about two or three hours a week. The motor had greaseable bearings and as I remember the manufacturer recommended a couple of shots of grease every five years when the motor was used 16 hours a day. The PM schedule could be scheduled for daily, weekly, monthly , every three months , twice a year , and once a year. So what would you do? Grease the motor once a year? Or not ever grease the motor?

Dan

==========

The machinery in the model shop I ran was Air Force property. They required it to be lubed weekly by a checklist no matter how little use it got or what the maker recommended.

--jsw

Reply to
Jim Wilkins

Were you the $#!+#=@[) who beat on the tailstock spindle like an anvil horn?

It was the only Heavy 10 among a batch of 9" South Bends and I couldn't pass it up. The dealer swapped the spindle but it's not a perfect fit. I haven't seen another 10L since for less than twice its price.

When I bought it there were still industrial suppliers in town. One had the proper Gits oil cups in stock, and a shiny new Eagle No. 66 oiler:

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--jsw

Reply to
Jim Wilkins

No such thing as "standard practice" Cheap motors used plain bearings. Many better motors used ball bearings. 50 years ago was only 1966

-ball bearings were pretty common - but usually not fully sealed or double sheilded. Many would have been "oil lubricated"uising thick oil, rather than grease - with felt or synthetic rubber seals. I remember some old repulsion start induction motors from the late fifties with oiled ball bearings, as well as some with oiled plain bearings - the big ball bearing motor was on the bale elevator. I think the motor on the pump-jack was also ball bearing, and the one on the cement mixer was plain bearing.- oiled, not greased

Some were even ball bearing on the drive end and plain bearing on the bell end

Reply to
clare

Cydrome Leader fired this volley in news:nj9g7l $i8t$ snipped-for-privacy@reader1.panix.com:

I think what makes more sense is that someone replaced the bearings with sealed. Later, someone ELSE, not realizing there were sealed bearings in there, and seeing the grease nipples, reasonably assumed it was intended to be greased, and did so.

LLoyd

Reply to
Lloyd E. Sponenburgh

Any reason for that, or why the shielded/sealed stuff took over? Was there some incredible development in stamping out shields or lubricants?

Reply to
Cydrome Leader

There have been big improvements in ball and race materials; modest improvements in their accuracy; and huge improvements in lubricants.

Reply to
Ed Huntress

Regarding lubricants, a mate in the automotive engine development industry mentioned that many car engine manufacturers don't harden the crankshafts these days as with improvements in the lubricants it isn't necessary to get the engine life.

Reply to
David Billington

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