bronze bushing advice

idacal · Mar 15, 2018

I have the bailer line on a cable tool drill rig that I have been eating bushings on this runs about between a 100 and 300 rpm I have replaced it 4 times in the last 10 years but usually by then I have about a .25 of slop in it every couple of years between changes is bearable, about 15 hours to change it. we grease it religiously about every 1.5 hours of run time but I think its undersized for the load. usually the machine shop makes a bushing out of 660 material now my question is, this time I had them make it out of a harder bushing material, this time I also moved the gear line up out a quarter of an inch, so Im not sure what to fix but I have a ear splitting howl when bailing and this is at any loading and any rpm to the point were everyone on site has to wear earplugs but gets worse as it gets higher rpm this bushing has less than 15 hours of run time on it, the last day on the job the zerk cooked itself shut and we couldn't get it to take grease so everything came back out. so educated guess would it be gear mesh or bushing thats causing the howl?

johnoder · Mar 15, 2018

Gears look worn out - not "tight" as far as mesh

Harder bronze could be C954 but be aware it will eat the steel (or iron) with any inattention to lube

How about lube grooves? Don't see any on the bronze - how do you expect it to get lube?

Is the bronze spinning in the bore when it is not intended to? How about some anti rotation for it?

Rob F. · Mar 15, 2018

Have you looked at Igus bearings? I have used to replace bronze in smaller aplications with great success. They have many different types, you should give them a call and listen to what they recomend.

Mechanola · Mar 15, 2018

Brass instead of bronze and grooves

Tyrone Shoelaces · Mar 15, 2018

Try buying a billet of " Oil-lite " and make a bush out of that.

Regards Tyrone.

idacal · Mar 15, 2018

well Im a dipshit I didn't don on me that it didn't have grease grooves and Im sure it is c954. so basically I was greasing it up and then squeezing it out first rotation. the gear is worn I will get measurements to make a new one. I dont mind noisy its a drilling rig but I didn't understand why it was suddenly howling, duh no grease. I have thought of a heavy bearing set but it moves back and forth on the bronze when the clutch is engaged. Any pattern of grease grooves? or is a certain pattern better?

tyrone I will see about getting some of that

Illinoyance · Mar 15, 2018

As Rob said, look at Igus. There are other brands as will. It seems unusual that the bushing is tight on the shaft and loose in the bore of the gear. That seems ass backwards.
Substituting a harder bearing material will just prematurely wear the mating part. I suspect non-metallic bearings will greatly outlast bronze.

Is there any chance you could ask the manufacturer how that bearing is supposed to fit? I think it should be tight in the gear and a running fit on the shaft.

spaeth · Mar 15, 2018

I'm with Illinoyance, should be pressed and pinned in the
bore and slide and rotate on the shaft. Grease grooves for
sure and maybe even some sort of seal to help hold the
lube longer.
spaeth

Rob F. · Mar 15, 2018

Another good thing about most of the Igus bearings is no gease is used. Here is a link to the Igus site:
https://www.igus.com/wpck/20693/agriculture

johnoder · Mar 15, 2018

There are machines that do this. Link has a video link. The important parts of a grooving job:

Wide and deep enough to hold some lube. I have seen tooth paste size (witdth and depth) grooves in a 3" bore

If you are feeding the middle, don't let the groove come out the end of the bush, just near the end

A few scratches are not going to do you any good

The better grooving rigs could do a closed figure 8 in a bore. You put the zerk at the intersection or "X"

Helical Oil Groove Cutting Vintage (2's?) Machine Video shot today. | Factory Daily

idacal said:
well Im a dipshit I didn't don on me that it didn't have grease grooves and Im sure it is c954. so basically I was greasing it up and then squeezing it out first rotation. the gear is worn I will get measurements to make a new one. I dont mind noisy its a drilling rig but I didn't understand why it was suddenly howling, duh no grease. I have thought of a heavy bearing set but it moves back and forth on the bronze when the clutch is engaged. Any pattern of grease grooves? or is a certain pattern better?

tyrone I will see about getting some of that

idacal · Mar 15, 2018

it is backwards from most things the bushing is tight on the shaft actually held in place by key ways and the clutch housing rotates on the bushing there is 4 sets of clutches on that shaft maybe done that way so that the main shaft isn't destroyed every time a bushing goes out it is 7' long by roughly 3" with multiple shoulders
plastic bushings! I will call them that seems almost wrong but I will call tomorrow on that
Johnoder that looks like an incredible machine. I called the machine shop that built this bushing for me they were as suprised by the no grease grooves as I was. told me we always put those in.

JS · Mar 15, 2018

Do you have better pictures? Trying to get an over all picture of the machine.

idacal · Mar 15, 2018

I dont have a working photo of the rig but here is some pictures of were the jackshaft comes out of and the jack shaft

JS · Mar 15, 2018

My usual got bronzes SAE 660 or 841 oil-lite.

Figure:

1: your clearances / renew any worn bores.

2: need to put seals on the housing.

3: grease grooves on bronze and a reservoir cavity in housing

My reasoning, I've done something similar in the past. My fix for my application was minimum clearances and something similar to boat axle grease, I can't remember the name of it, but it was tacky if not more tacky then boat grease.

Anyway the fix ran at cold or room temperature at roughly 500 rpm. Grease was checked before startup.

It actually polished the bronze after several years of use.

stephen thomas · Mar 15, 2018

If you continue with bronze, I have to wonder whether oil would not provide a large step up in longevity. I know it is slow speed, but a good size reservoir, some heavy gear oil or maybe even way oil (Ok, chainsaw bar oil

) with a drip feed would have been the first thing I added after the first overhaul back when. Tyrone's suggestion of oilite provides a safety margin with grease or oil lube due to being oil saturated. But oilite compresses. so that may or may not be a factor.

Plain bearings become durable when they develop hydrodynamic properties. That bearing is squeezing all the lube out, at least at some periods during the maintenance intervals. Can it be sealed to increase the pressure a bit before the lube departs?

Final thought, that being a cable rig, it runs 24-7 for weeks at a time? Months? If it is running 3000+ hours/year, maybe you are already getting pretty good service?

smt

Mechanola · Mar 16, 2018

Lube groove(s) helical form like very steep threads. Plural when you make two in opposite ways, crossing

Limy Sami · Mar 16, 2018

+ another on all that's been said, .......... PLUS pick the right grease for the application, ........I'm not sure why, but in applications like the OPs, molyb' disulphide, graphite and extreme pressure additives have always served me well.

idacal · Mar 16, 2018

thank you all for the advice Im calling Igus this morning. I'm kind of a creature of habit and plastic worries me If id decide to go back in with bronze I will use the 660 I had them made out 841 the first time around 8 years ago (I looked through my notes) and they didnt last any longer. (and this last time without the grooves was aluminum bronze) and I will start using a grease thats a little better for it up till now I I just used the red grease thats 30.00 for 12 tubes.
stephen thomas I dont do much actual drilling with this rig maybe 3 wells a year that are in tight locations. I mainly do fishing jobs on dropped pumps and clean outs on large wells that are installed in buildings. making a living with one of these old rigs doing domestic wells is backbreaking work but that was how I started. plus I have a rotary for that now. rig may run 300 hours a year but it still has its place and worth keeping fixing. I have thought about using oil and felts? but the zerk is in the rotating housing so I would need to build a oil reserve that could rotate and handle a lot of hard starts and stops without breaking off, and still hold a decent amount of oil.

Mechanola · Mar 17, 2018

Since you say felts, maybe sand is a problem. Felts would keep dirt out, very important. No bearing can withstand mineral particles. Lastly, the better the fit, the longer it will last. You can lap two parts to each other but then all abrasives have to go.

rj1939 · Mar 17, 2018

Maybe the lack of use is causing the problem? Corrosion/debris/dirt accumulating in the down times, goes to work on the bushing once it is fired up again.
It doesn't seem like the speed or the load is cause for a problem, so just trying to think out of the box

bronze bushing advice

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