It has been suggested that the above will work in the beginning of the thread. C3 - what we need.

 

#1) N/A
#2) steel or ceramic
#3) The sealed bearing gets a little hotter usually sealed in a rubber like material to keep ALL dirt and water out. A shielded is far from actually sealed from especially water
#4) N/A
#5) N/A
#6) steel is fine will out last brass but you probly would not find this bearing with the brass cage
#7) the looser the tolerance or class the better for heat reduction and RPM
#8) ? no idea what this is asking?
#9) a smaller bearing will have a higher RPM rating simply due to mass. One would not expect a bearing with basket ball size ***** to run at 20,000 rpm...
#10) more ***** is BAD each ball generates heat more ***** the more heat, plus mass.
#11) welcome to page one of this discussion. When we figure this out I will let you know.
I have the right bearing if we put a shim in the pulley and a stud with a smaller shaft with a nut. I should know this week if the bearing companies engineering department will allow it's manufacturing department to manufacture a bearing the same size as ours that will fit the bill.
Mike

 

We are working on it quickly

Quote:

Hi Scott, taking the snap ring out was not a problem. Getting the press fit bearing out of the retainer is not that big of a deal. Getting to the ball is a big deal because you have to break open the dust shield. Once you get the ceramic ***** in, which is no small feat, you dont have a usable dust shield anymore.

The NSK bearing is common however, and they have a hybrid line that utilizes ceramic *****. They install the ceramic ***** at the factory so the dust shields still have their integrity.

Here is a link. I have sent the company an request for quote for a hybrid bearing with the correct bearing number. http://www.republicsales.com/products/blowers/republic-centrifugal-blower/nsk-ceramic-ball-bearings/

Not something that can be completed by a novice however as you have to toast the dust shields to disassemble the bearing.

Jeff

 

Just delivered to my office today:

Two hybrid ceramic bearings (custom made) with the same dynamic and static load ratings and the same clearance specifications as a standard "6303" bearing.

It's rated with a "100%" constant duty cycle of 15,000 RPM and can operate up to 20,000 RPM for less then 20% of the duty cycle time without effecting MTBF or damage to the seals or grease.

Think I'll try one and give MikeR the other to test....

Houston - we may have a solution....

Oh yea - and I got a camber kit (front and rear) to install.....

 

I have the right bearing if we put a shim in the pulley and a stud with a smaller shaft with a nut. I should know this week if the bearing companies engineering department will allow it's manufacturing department to manufacture a bearing the same size as ours that will fit the bill.
Mike

I am afraid that the smaller bearing, although it may have a higher rpm rating probably cannot take the load. Reducing the bolt size weakens the whole assembly. This option losses out on both counts.

 

BrianBrave - sounds very promising!!

A week ago Jerry posted that he was starting a new thread with the latest info - did this happen? (if he did, I missed it - but I was travelling).

Thanks everyone for working towards a proper solution for this bearing application; the knowledge and efforts of those offering constructive contributions are greatly appreciated.

 

1, Increaased load reduces life unless the rpm is decreased.
2, Size for size Ceramic Hybrids have higher rpm limits, and slightly lower load limits.
3, Seals get hotter at high rpm's and wear away the lip. They will still do a better job than shields.
4, plastic/rubber seal or steel shield
5, Grease (use one seal/shield and you could repack at intervals. That depends on the enviroment, maybe too dirty in this case)
6, Steel or possibly reinforced nylon.
7, Class 1,
8, Size of bore and shaft can have an effect on ball clearance in the bearing.
9, Smaller bearings can run faster but the loads limits are much lower.
10, More ***** increase the load rating but reduce the rpm rating

Not all the above have to be taken into account in this case. I have found as many others that Ceramic Hybrids appear to fit the requirements. An SKF bearing #6204-2RSL TN9/HC5C3WT is 20mm x 47mm x 14mm has a rating at 30,000 rpm with a slightly lower load rating than the 6303 series but can take higher rpm's so may be a good choice, requires a larger spindle. A 6303 Hybrid may still be better, it is hard to figure out the proper speed/load relationship.

As one of the posts said, it may be cheaper to replace them every 'X number of miles or after hard driving at the strip a few times and don't worry about it. Because if they fail they cost a lot in damage.

 

Not yet, I'm waiting on a firm shipping date from overseas.

We have a custom bearing being made for our application.

 

I'm rdy to order a couple of these bearings! Keep us posted...Thanx......

 

Anybody know where I can buy a temporary replacement idler pulley? I have my WP pulley now, but the idler bearing seems to be starting to seize so I need something to tide me over till LET gets the new bearings in. I don't want it to seize and snap my belt and who knows what else while I wait for the new bearings to come in.

 

Well I have heard from the Bearing manufacturer and the news is this.
From the engineering department they write they are unwilling to manufacture the said bearings using ceramic ***** in the steel races. This comes based on the companies liabilities standards.
Sorry guys no one wanted these more than I.
Mike Loftus

 

Can anyone with a 185 pulley verify my measurement of the idler pulley at 2" 1/4 diameter?

 

BrianBraves's post #16 puts the diameter at 60mm
60 / 25.4 =2.36" diameter

 

Making a bearing for a specific task does puts the manufacturer on the hook. Putting the same bearing on the shelf as a stock item puts the onus on the user. The bearing in question would have been too expensive anyway.
The bearing you have with a smaller shaft and a shim(?) is a non starter as well I guess? If not please explain in depth, we are all ears.

 

There are many ways to solve the problem, I have been doing my research. It is COMMON to find 6203 bearings that will go 15,000 and ZZ series are good for 17,000 for less than $10.00 each.

The real deal is to have the speed of the pulley lowered to increase the service life. Even I only run the engine up to 6000 and hold it for a max of 60 seconds, the limits are largely a function of heating and LOAD. Most 6203's I have researched on a 5 or 6 sites are capable of a radial load of OVER 1000 pounds.

In our tensioner the leverage that I need to pull off the belt is about 30 - 50 pound feet of torque. Thats a lot less than 1000# of radial loading and they are really chillin so to speak. There are only two pulleys under that stress the one below the toothed S/C "idler", and the one on the tensioner itself. This is due to the amount of WRAP of these pulleys, about 180 degrees which is way more than double the other 'toothed' idler on the S/C. THe accessories are tougher and probably have shaft bearings at each end like the alternator.

Like the Super cooler radiator I developed and currently have on my car to eliminate the over heating of the H/E, Iam doing an ALPHA level test of a different approach to solving this pulley problem. It should be BETA level tested enough to start getting it into a kit of parts to solve it for real early in 2009. I am hesitant to sign off or release anything to production that will fail and cause angry feelings DOWN the ROAD so to speak. Were all tot familiar with thoes type of events.

Have a happy holiday, see you guys on the other side of the holidays, W DY

 

Go Woody!
If you need a guinea pig you know how to find me!

 

BUMP.... anyone fix this problem from way back

 

LET has a 19,000 rpm bearing available.

$20 here