Sliding Shaft Lubrication

[xr4titis]

Hello Forum,

I can't seem to find any information on lubrication for a shaft sliding in a hole. I have a simple situation of a shaft sliding back and forth inside a hole at no great rate of speed or frequency, but it will be subjected to extreme weather and is expected to last forever.
My thoughts are longitudinal grease grooves along the shaft or perhaps a grease hole. I don't think seals are an option due to the added cost and poor surface finish.
Any related information and/or similar applications are greatly appreciatied.
Thanks,
Andrew

 

[desertfox]

Hi xr4titiis

It might help if we knew more about the application, extreme weather conditions:- hot,cold, humid, corrosive.
whats low speed? and frequency of operation?
loads involved and not least some materials.
All we have so far is a shaft going in and out of a hole
which could be anything.

regards

desertfox

 

[xr4titis]

hey desertfox,

sorry for the vague description. Temperature range is -50F to 130F and is also subjected to water and dirt. The sliding shaft and part housing the sliding shaft are both galvanized steel, however, i'm not sure I'll get the hole tolerance I want after galvanizing, so that may be bare metal. The hole is 1/2" diameter, the length of the stroke is 1/2" max. I have no way of determining the velocity of the stroke, but it will have roughly 800lb of force behind it, so high friction lubrication should not be an issue. Frequency is a non-issue as the unit will be used intermittantly.
Also, I cannot make the hole any more than .63" for a plastic spacer as the part containing the hole is subject to high tensile force and all the plastic spacers I've seen have a wall thickness >.12"
thanks,
xr4titis

 

[desertfox]

Hi xr4titis

I doubt that it will last 5 minutes if you have any bare metal showing subject to water and dirt.
Also at -50F you could have that steel go brittle and fail.
Again to little information what is this thing doing, does it matter if water gets into the housing or can it drain away? what size is the shaft? I assume the material is mild steel seeing as its being galvanished, why not use a stainless steel which might be a lot better.
If you can load up a drawing of the device.

regards

desertfox

 

[xr4titis]

Hey desertfox,

Shown in the picture is the "housing" the vertical post with the hole and the "shaft" running through it. The housing intermittantly rotates a total of 90 degrees in both directions. The shaft sticks out to lock the housing in various positions. Though these two are shielded from the elements, they are not sealed.

 

[xr4titis]

sorry try again

 

[desertfox]

Hi xr4titis

Have a look at these journal bearings, I would be tempted
to try and use these as they are very low maintenance.

http://www.ahrinternational.com/Glacier/Glacier_Du_DX_Catalogue_1.pdf

I would still be concerned about temperature from a point of view of material going brittle and I don't think you will avoid corrosion over the passage of time with the galvanised steel.

regards

desertfox

 

[xr4titis]

thank you desertfox. I just needed to get the grease out of my head

 

[desertfox]

Hi xr4titis

Your welcome and best of luck.

desertfox

 

[unclesyd]

Aside from the bearings/bushings suggested by desertfox you might want to look at this line of Graphalloy Bearings.

http://www.graphalloy.com/html/bushlist.htm