Angular contact ball bearings according in small size 1

[conrad1]

Hi,

i´m looking for some small angular contact ball bearings for an aircraft application. The maximum OD shall not exceed 7/8". I found some Mil specs with a suitable type, but all sizes were too big. My own feeling is that there must be a bunch of specs, but i wasn´t able to found something. Maybe, someone has a number in his mind.
Does someone know if the MS27641 ball bearing has fill slots for the balls?

Thanks!

 

[WKTaylor]

DO YOU Mean... angular... or annular... or angular and annular???

http://quicksearch.dla.mil/qsSearch.aspx

Search for...

MS27641 BEARING, BALL, AIRFRAME, ANTI-FRICTION, INTERMEDIATE DUTY (S/S BY SAE-AS27641)
Per procurement spec AS7949 Bearings, Ball, Airframe, Antifriction, General Standard for
3.8 Plating (Except for the AS27649 Bearings):
When tested in accordance with 4.5.6, all external surfaces of the bearing excluding the inner ring bore and chamfer, seal retainers, and seals, shall be cadmium plated per AMSQQ-P-416, Type I, Class 2 or zinc-nickel plated in accordance with AMS 2417, Type 2. The plating thickness shall be 0.0003 to 0.0006 in. The plating thickness of the bore
chamfers shall be a maximum of 0.0006 in. Plating on the ball loading slot is optional.

NOTE: Superseding spec AS27641 [PNs remain MS27641], dimensional illustration, clearly shows a ball loading slot between inner/outer races

A-A-59643 BEARINGS, BALL, ANNULAR, SINGLE ROW, RADIAL, NON-FILLING SLOT, MINIATURE SIZE, INSTRUMENT TYPE

A-A-59644 BEARINGS, BALL, ANNULAR, SINGLE ROW, RADIAL, NON-FILLING SLOT, EXTRA LIGHT SERIES (R - SERIES)

MIL-B-913/* BEARINGS, BALL, ANNULAR, FOR INSTRUMENTS AND PRECISION ROTATING COMPONENTS (METRIC) ...

MIL-B-81793/* BEARING, BALL, ANNULAR, FOR INSTRUMENTS AND PRECISION ROTATING COMPONENTS, ANGULAR CONTACT, UNFLANGED, NON-SEPARABLE AND COUNTERBORED OUTER RING, ...

FYI...
MIL-HDBK-1599 BEARINGS, CONTROL SYSTEM COMPONENTS, AND ASSOCIATED HARDWARE USED IN THE DESIGN AND CONSTRUCTION OF AEROSPACE MECHANICAL SYSTEMS AND SUBSYSTEMS

Regards, Wil Taylor

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[Sparweb]

I'm pretty sure the OP Conrad1 means "Angular Contact" ball bearing.
But the MS27641 is not an angular contact bearing, so I can see where some of the confusion is coming from.

Go back to the ASSIST link from Wil's post, and use these terms in the title instead:

BEARING, BALL, ANGULAR

..And many results will appear.
Some specify non-filling slot, and many state that they comply with ABMA standards, too.

STF

 

[tbuelna]

conrad1-

You use the term "aircraft application" in the OP, which can mean different things. Can you provide a more specific description of your particular application?

The primary consideration with components (including ball bearings) used on an aircraft product that has been certified/qualified is ensuring quality control of the component. Procuring a component manufactured to an existing standard, such as MS/AN/AS/NAS/etc, is one way to do it. Another way is to procure the component using your own specifications defined on something like a Source Control Drawing.

There are several manufacturers that offer standard precision instrument ball bearings (including angular contact) in the sizes you are looking for. If you find a vendor that has AS9100 QA certification, they will usually be happy to supply you one of their standard bearing designs with documentation showing compliance with requirements of your SCD.

 

[conrad1]

Hey guys,

thanks for your replies. An angular contact bearing would be the best choice in order to preload the bearings. The MS27641 is another option, but maybe difficult in terms of preloading because of the ball loading slot.
I´ve found some angular contact bearings using your link above. But most of the datasheets don´t provide load capacity information, espeacially the "instrument and precision component" bearings. I don´t know the reason.

The application is an oscillating (slowly moving) lever arm consisting of two aluminium plates. A shaft connects the two plates and is fixed by the inner rings of the bearings. The outer rings are fixed in a kind of a housing between the plates.....yes the two plates are really looking like a clevis joint.
Preloading is needed for an accurately aligne movemnet of the lever arm.

 

[tbuelna]

You can find NHBB small size angular contact ball bearing dynamic and static load ratings here. You can find the life calculations here. And you can find recommendations on pre-loading here.

If you want to perform the calculations for dynamic and static load capacity yourself, you can find all the information you need in ANSI/ABMA 9-2015 Load Ratings And Fatigue Life For Ball Bearings.

Good luck with your project.

 

[Tmoose]

"The application is an oscillating (slowly moving) lever arm consisting of two aluminium plates. A shaft connects the two plates and is fixed by the inner rings of the bearings. The outer rings are fixed in a kind of a housing between the plates.....yes the two plates are really looking like a clevis joint.
Preloading is needed for an accurately aligne movemnet of the lever arm."

I'm sorry, but that description leaves me scratching my head.

Dimensions and load capacity -
pages 14-22 here -

https://www.bardenbearings.com/remo...loads_25/barden_speciality_products_us_en.pdf

 

[conrad1]

Sorry for the rough describtion. Barden bearings looks not bad. I already tried to get in contact to them - thanks for the advice!