On 10/8/2016 at 3:19 PM, tutsiwarrior said:

with an intermittant sliding operation rather than a continous high speed rotating action bearing lubrication should hot be a consideration...talkin' about roller skate wheels here that can handle a bit of low load friction...

 

gonna start talkin' about lube oil cooling systems next...flushing procedures and particle count criteria, etc...

The theory is indeed correct - but dry bearings = rust\oxidization due to water ingress - it doesn't take long for the bearing surface to be be pitted which vastly increases wear, they are not the best quality bearing to begin with! They could off course put a sealed bearing in! A little grease will prevent exposure to air, water and dirt getting into the bearing - simple enough!

If you want to change them every couple of years leave them dry.

On 10/5/2016 at 0:34 PM, Anthony5 said:

As the title says, I want to replace the wheels from my sliding gate.

 

Now to give you an idea, my gate is 2 meter high and 9 meter long, and has about 5 cm spacing between ground and gate.

 

Impossible to get a car jack under it, and impossible to lift, so how do I replace the wheels?

 

Jackbar & Fulcrum would be your best friend here

3 hours ago, CGW said:

The theory is indeed correct - but dry bearings = rust\oxidization due to water ingress - it doesn't take long for the bearing surface to be be pitted which vastly increases wear, they are not the best quality bearing to begin with! They could off course put a sealed bearing in! A little grease will prevent exposure to air, water and dirt getting into the bearing - simple enough!

If you want to change them every couple of years leave them dry.

 

 

yeah...I hear what yer sayin' but bearing mat'ls are usually selected fer the conditions which are harsh and exposed, including roller skate bearings...I've never seen a mild steel roller bearing...have you?

 

it would be like putting carbon steel in contact with sea water (which I have seen in temporary, disposable arrangements...)

 

(and de arab client comes and sez: 'tutsi, that seawater discharge arrangement is unacceptable!...' 'tutsi then folds his arms and consideres him ironically: 'well, ye know, Abdullah, it was discussed and agreed upon in the meetings that you missed...and after all, ye get what ye pay for...' and then tutsi considers travel arrangements as he has once again told the client what he don't wanna hear...)

 

 

^ Are the bearings used for rolling a gate on designed for this purpose? off course not, they are not designed to have the weight of a gate point loading it! they are designed to spin, generally on a shaft where the load is equal and far less than they are subject too in this instance - if you & Tutsi have decided the high quality bearings don't need grease and you will get the same life out of a un-lubricated bearing, despite the increased friction and all the other factors already discussed - up to you!

OK...I agree that enclosed, permanently lubricated bearings are suitable for the discussed application...

 

however, I don't think that the bearings much care if the load is a point one or nicely distributed...

 

but, what do I know? I'm a conventionally fired power generation process man...recently retired...

 

(and then Tonto comes up and points and sez: 'what about them boilers, kimosabe? there are many main steam support arrangements that are not suitable and that are not confirmed by the flexibility analysis' 'leave it to the ragheads...let's go find ourselves a drink...')

 

 

 

 

^ Note to self, do not buy a used gate from "tutsiwarrior" what do I know? recently retired after 40 years marine eng.

Cheers

right on, pardner...let's go get ourselves a drink...we deserve it...

 

and I gots lotsa used gates out behind the shophouse...but they are pneumatic and ain't got no bearings...'floating on air' technology...

2 hours ago, CGW said:

^ Note to self, do not buy a used gate from "tutsiwarrior" what do I know? recently retired after 40 years marine eng.

Cheers

 

Hey everybody knows you "Engineers" just change oil and blame operators 

^ Yes! & your point is? actually we make sure bearing are greased as well!

15 minutes ago, CGW said:

^ Yes! & your point is? actually we make sure bearing are greased as well!

 

Lol yeap thats the other thing you guys do - if its metal its greased and wrapped - or painted - then greased 

 

How is this even a thing in this thread though? 

 

Lubricate moving parts.... It kinda, you know, makes it move easier & stuff

Yes very important.