Angular Contact Ball Bearing Race Detailing
Angular Contact Ball Bearing Race Detailing
(OP)
Does anyone know of a good reference for producing a detailed print of a bearing race (outer or inner) for an angular contact ball bearing?
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS Come Join Us!Are you an
Engineering professional? Join Eng-Tips Forums!
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail. Posting GuidelinesJobs |
Angular Contact Ball Bearing Race Detailing
|
Angular Contact Ball Bearing Race DetailingAngular Contact Ball Bearing Race Detailing(OP)
Does anyone know of a good reference for producing a detailed print of a bearing race (outer or inner) for an angular contact ball bearing?
Red Flag SubmittedThank you for helping keep Eng-Tips Forums free from inappropriate posts. Reply To This ThreadPosting in the Eng-Tips forums is a member-only feature.Click Here to join Eng-Tips and talk with other members! |
ResourcesThe world has changed considerably since the 1980s, when CAD first started displacing drafting tables. Download Now
Prototyping has always been a critical part of product development. Download Now
As the cloud is increasingly adopted for product development, questions remain as to just how cloud software tools compare to on-premise solutions. Download Now
Engineering-centric businesses face a number of challenges today, but unmanageable design and change processes don’t need to be counted among them. Download Now
|
RE: Angular Contact Ball Bearing Race Detailing
Are you going to have races made?
The interior dimensions depend on the number of balls, which sometimes varies a bit between manufacturers or decade of production.
Also the race profile includes the "curvature" which is juggled a bit by application to buy speed capability or load capacity, so is proprietary and can vary between mfrs too.
RE: Angular Contact Ball Bearing Race Detailing
RE: Angular Contact Ball Bearing Race Detailing
There have been some outfits that design and manufacture specialty bearings.
looks like these guys are still around
http://nhbb.com/
RE: Angular Contact Ball Bearing Race Detailing
The operative word in your question is "detailed". Modern rolling element bearings are very highly engineered products, even "off-the-shelf" bearings. When purchasing custom bearing components or assemblies, such as those you are inquiring about, there are two ways to approach the documentation issue. One way is to use a "source control drawing", which defines certain requirements for the parts as delivered, but otherwise leaves the particulars such as heat treatment, QA, etc. to the discretion of the vendor. The other way is to provide a complete set of engineering documentation that defines every aspect of the manufacturing and QA processes.
The complete documentation needed for a high performance angular contact ball bearing race can be quite extensive. For example, specifying micro-inch level geometric (roundness, taper, runout, etc.) and dimensional tolerance limits and how they are to be measured (free state, constrained, etc.) is no easy task. Specifying the precise details of race surface finish (roughness, lay, etc.) can be critical for fatigue life or scuffing resistance. With angular contact ball bearings in particular, it is common to design the inner and outer races with slightly different operating contact angles. But the only way to verify that the bearing assembly has the correct operating contact angles is by using a specialized test fixture. Lastly, as Tmoose noted, the inner and outer races of angular contact ball bearings typically use slightly different "osculation" curvatures to help equalize contact stress levels and optimize efficiency. Do you know how to determine these?
Manufacturing quality rolling element bearing races requires highly specialized equipment, facilities, and expertise. There are lots of bearing companies that will make custom designs in small quantities. Since manufacturing bearings is a job best left to professionals, I'd highly recommend that you create a source control drawing for your bearing assembly that defines some basic dimensional and performance requirements, and then submit that to a competent vendor.
Best of luck to you.
Terry
RE: Angular Contact Ball Bearing Race Detailing
RE: Angular Contact Ball Bearing Race Detailing
Design your whatever to use a stock bearing.
RE: Angular Contact Ball Bearing Race Detailing
RE: Angular Contact Ball Bearing Race Detailing
RE: Angular Contact Ball Bearing Race Detailing
RE: Angular Contact Ball Bearing Race Detailing
Are they a standard part number?
How big are these bearings?
Do you have any details about the race "wear?"
If the races are wearing my first hunch is the lube or sealing could be improved. My second hunch is the balls are suffering too if they are steel.
In some conditions Ceramic balls running on steel races survive MUCH better.
Like dinjin said, there are houses that can refurbish bearing (races).
RE: Angular Contact Ball Bearing Race Detailing
pabolton-
With rolling element bearings, if any individual component of the assembly has any damage or wear, it is usually not a good idea to simply replace that component. Unless it is an emergency, it is better to replace the entire bearing assembly.
If you want to reduce the cost of bearing replacements, you might look into re-manufacturing your bearings. If the wear on the race surfaces is not too severe, they can be salvaged using thin-dense chrome plating and regrinding. The cages could probably be re-used and the only parts that would need to be replaced would be the balls.
RE: Angular Contact Ball Bearing Race Detailing
RE: Angular Contact Ball Bearing Race Detailing
Do you mind sharing more about the equipment?
How often are bearing components replaced? Less than 5 years?
I'm real interested in the fact rolling element bearings "wear" in service, and the OEM allows, let alone advocates piecemeal replacement.
Qualifying the races/balls of a conventional bearing as "re-usable" is along the lines of they have to look uniform and feel perfectly smooth in 3 dimensions, with light visual frosting permissible in the ball path. Anything less is likely to yield pretty short life before more serious deterioration begins and will likely progress rapidly.
Balls or rollers re-used because the "don't look to bad" are likely to have pretty short second lives along with their brand new step brothers, which would result in greater repair frequency.
If the "wear" is not from contamination, then I'm thinking the lube may be too thin to achieve a decent kappa and EHD lubrication. I'm guessing the rpm are low. Lube with EP and antiwear additives can drastically reduce "wear" when EHD can not be achieved.
RE: Angular Contact Ball Bearing Race Detailing
If that's your aim, then I would reverse engineer it. Measure it yourself, convert the profiles to something that can be manufactured, cut it and do microhardness traverse tests. If the capabilities to reverse engineer it are not available, then the capabilities to make your own are also not available.
David
RE: Angular Contact Ball Bearing Race Detailing
Tmoose I'm also surprised the OEM allows for piece part replacement on the bearings, the balls and inner race very rarely show the amount of wear seen on the outer race mainly due to the application.
RE: Angular Contact Ball Bearing Race Detailing
www.winball.com/tolerances.htm
The races need to be as good.
I have no idea if the grade you have been receiving is really required for your application.
There are many possible explanations for outer race "wear." Inadequate sealing, improper lubrication, improper race heat treatment, heat treatment damaged by aggressive or improperly cooled race grinding, etc. etc.
http://www.koyousa.com/brochures/pdfs/catb3001e.pd...
This link discusses some of the extreme finishing methods necessary when very accurate motion and low noise is required. I'm guessing your application (whatever it may be) is not concerned about those requirements, but it also hits on how the race surface must be nurtured and preserved. Also the relationship on speed and lube viscosity and even surface finish on "good" lubrication.
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.g...
RE: Angular Contact Ball Bearing Race Detailing
RE: Angular Contact Ball Bearing Race Detailing
pabolton- I've attached a sample SCD for a duplex angular contact ball bearing from a NASA document. You can download the whole document here: http://hdl.handle.net/2060/20070018937