Lubricating linear bearings

[millman52]

Most all the bearing carriers for linear rail have a brass, ball check grease fitting. Different size rails have different size brass "zerks"

My question is: What sort of "gun" fitting is used to force grease in them. For that mater what sort of gun should be used? A standard automotive style grease gun is a bit bulky & always a mess to use.

[millman52]

Hmmmm, Aparently no one performs maintenance on their linear rails?????

[LeeWay]

Grease zirks are usually brass colored but are typically zinc coated steel. They do come in different shapes and sizes. The same thing goes for the guns. They do have small tubes of grease, maybe 8 " long. They have smaller guns that these fit into. Some work the same with a lever and some have a trigger. Some of the larger ones are even air assisted. Usually used with large drums of grease at oil change shops.

There are also many different types of fittings and sizes for the ends of these guns. I have found the standard fitting works okay on my THK HSR25's and HRW 27's, but some designs are much tighter.
In such cases, they have what is called and needle adapter. This doesn't fit over the ball end of the zirk, but rather just inside the hole for the ball plug. Then just apply pressure to it and pump away. These are espcially useful for greasing U-joints on certain vehicles.

[woodman08]

there must be a lot of cnc machines not getting grease as I see i'm not the only person who cannot grease a bearing because the fitting is like nothing anyone has seen ,I have been told its a fitting to fit a regular gun like a needle with a 90 degree bend and you push the sharp end into the brass fitting and give it a shot,but where to get something like this.
The manufacturer that built my machine does not know how to grease it amazing

[Geof]

Can you replace these oddball fittings with standard grease nipples. I have five commercial machines with ballscrews and linear guides that have to be greased manually just using regular grease; these have regular grease nipples.

[woodman08]

this is where the router is attached and there is no clearance but its is an option that i will look at ,i even contacted the people that built the bearing and there was no reply.

[Fixittt]

its a simple design, I used a hobby lube bottle with a long skinny tube on it, I use the end of the tube to push in the ball on the center and squeeze some waylube 68 into the truck. SAme thing with the oil port on the sherline table face, push the ball in with the end of the little tube, I do make sure that once the ball on the oil port, that I shift the tube a little so the end of the tube is not being blocked by the ball and squeeze in a bit of oil.

[FT_factorytuned]

What I've found is that most manufacturers of linear bearing systems also have an "optional" oil feed system. It would seem as though grease is not the preferred idea because of contaminate loading and locations. My tools use THK 35's the fittings are two-piece, with metric 5.5mm thread. The previous owner, because of space constraints, stripped a fitting seat being to ruff. So I removed the fitting and used it on the backside seats, as they are more accessible to load the bearings that were difficult to get to.

My gun is a standard pump large sleeve gun with flex line and adjustable collet, purchased from Travers. It works quite well with very little over shoot or seepage. I did however have to machine a 45 deg chamfer on the head. I use pure CrMo grease in a high-pressure high temp suspension. This grease will break down rather rapid when mixed with oil. However it is superior grease. Coolant has very little effect on it. This actually works well as I can us WD40 or recommend DRY Lube to break it down, wipe the rails clean and dry, pump the bearing blocks, and I get a nice bearing whip pattern in this silver gray grease which assures me they packed. The machine travels more quietly as well.

Hope this helps.
FT

[LeeWay]

McMaster Carr carries lots of these fittings and zirks.
Here is a 90 degree needle fitting that you might be able to use.
http://www.mcmaster.com

Look at pages 2142 throough 2146.

[millman52]

Originally Posted by woodman08 there must be a lot of cnc machines not getting grease as I see i'm not the only person who cannot grease a bearing because the fitting is like nothing anyone has seen ,I have been told its a fitting to fit a regular gun like a needle with a 90 degree bend and you push the sharp end into the brass fitting and give it a shot,but where to get something like this. The manufacturer that built my machine does not know how to grease it amazing

Mine have a brass fitting similar to yours. If you were to replace the radius on the end of yours with a taper It would look the same. I've tried a "needle attachment" Purchased locally at an auto parts store. seemed I got grease everywhere but in the carrage with that.

Mine looks as if the end of the applicator needs to be inverted V shaped. Still it would require parallel access to the fitting to work well.

I have resorted twice now to actually removing my Z axis from the bearings. Sliding the bearings off the end of the rail & manually packing the balls with gerase. Repeat 3-4 times till I'm sure I have worked grease in the carrier & as much contamination out as possible.

This is very time consuming not to mention much more tedious than need be.

I have searched various brg. mfg. sites & no where do they offer a lubrication tool. In my case the bearings are IKO.

I'm soon going to replace the problem all together with either Franke or Parker/Origa rails & carriges that use sealed permanently lubricated needle roller bearings http://shop.franke-gmbh.de/en1/linea...ke_dynamik.asp http://www.parkeroriga.com/prod_alum...er_guides.html

My personal opinion for a plasma table Is: There is no real way to keep the fine dust that Oxy or plasma creates out of recirculating ball type precision liner rail. My table gets near 40 hrs a week use & I have worn out an IKO rail & 2 bearing carrages in a year. The above listed rails should wear much longer as they will be much more self cleaning.

[FT_factorytuned]

If your running the tool in production, which would appear to be the case, I'd stick with the IKO or some similar system. Plasma etc., does generate some nasty particles.

Here it comes, the "advise"; Would probably be best to invest in an bijur auto lube or some similar product, so quinching happens all the time and rinses debree from the inside out, replace and maintain the wipers. You would never look back. But you would have to do the piping yourself. As well as replacing the zirks with your own fittings in the bearing blocks and install TFE and stainless clad or some other type lines. I have copper pipe hard lines on one of my tools with the aforementioned system with stainless clad flex lines.

VAC-2 dripping everywhere may not be an option however.
Good luck!
FT

[millman52]

Originally Posted by FT_factorytuned If your running the tool in production, which would appear to be the case, I'd stick with the IKO or some similar system. Plasma etc., does generate some nasty particles. Here it comes, the "advise"; Would probably be best to invest in an bijur auto lube or some similar product, so quinching happens all the time and rinses debree from the inside out, replace and maintain the wipers. You would never look back. But you would have to do the piping yourself. As well as replacing the zirks with your own fittings in the bearing blocks and install TFE and stainless clad or some other type lines. I have copper pipe hard lines on one of my tools with the aforementioned system with stainless clad flex lines. VAC-2 dripping everywhere may not be an option however. Good luck! FT

FT_factorytuned:

If it were a machine tool other than a Ox/Fuel-Plasma burning center your advice is spot on & would alredy be in place. The "Oil Dripping" would be a constant mess & possible hazzard on a burning table.

My goal is to lengthen the life span of the rail. Being ultra tight isn't an issue as a torch process by it's very nature isn't perfect.

The above mentioned rail & carrages have the bearings themselves sealed & permanenetly lubricated. There is going to be wear on the rail & OD of the bearings. As the "Y" axis in this case gets regular travlel over it's entire length, the rail itself needs no lubrication, & the preload on the bearings can be adjusted as wear does develop. The assembly should give much better life than the year or so that THK,IKO etc gives.

Don't get me wrong THK, IKO & a host of others with recirculating ball is very fine rail & certainly be the linear motion of my choice on other more clean environment applications.

When I built this table I scrounged a used piece of this same type of aluminum rail for use on my Z axis. True it doesn't see as many travel cycles as the Y but it's closer the heat and in direct line of fire of all the smoke & grit. It doesn't seem to collect any dust & still as tight as the day it was installed. I'm sure in a big part because there isn't a lube film left behind to collect dust each cycle.

Thanks to all for your imput & welcome further comments.

Neil