Datums on Spherical Bearings

[RLD89]

I need help, or ideas, on DRF callouts for 3 spherical bearings. How can you callout 6 DOF with three points? Any ideas are appreciated.

 

[chez311]

RLD89,

Any chance you could provide a little more information on the application?

Are trying to develop a DRF or each individual component of a bearing separately (inner race, outer race, cage, etc..) pr a bearing assembly as a whole? Or is your reference to "three points" instead about three different bearing assemblies (or their mating pockets in a housing) inside a larger assembly/component?

An existing or similar print would be helpful as well.

 

[RLD89]

I do not have a drawing, this is an initial concept without a print. They would be three individual bearings that would be in a single assembly and not attached to the same part in that assembly. They are not coaxial, but two of the three would be coplanar (if the bearings did swivel).

 

[chez311]

RLD89,

Are there shafts or flanges mated to the bearing ID's which are part of the assembly for which you are responsible? Are the bearing axes all parallel?

Edit: also a little confused by what you mean by the statement that 2 of them would be co-planar "if the bearings did swivel"

 

[ewh]

I'm not sure how this applies to your bearing situation, but you can set up a datum structure with only three points - all three for the primary plane, the secondary perpendicular to the primary and through two of the points, and the tertiary through one of the points and perpendicular to both the primary and secondary.

"Know the rules well, so you can break them effectively."
-Dalai Lama XIV

 

[Tmoose]

My idea is for me to you wait until you return from your 3 week vacation and have provided some more information in the form of pictures or sketches.
You lost me RLD89.

http://sc01.alicdn.com/kf/HTB1l31ONXXXXXXQaFXXq6xXFXXXO/cv-joint-tripod-joint-bearing-for-nisan.jpg

https://encrypted-tbn0.gstatic.com/...YPchossWSwPWhwagVRKlpcaD8tL5daALM-Ms99dgs48E5

https://www.neimagazine.com/uploads/newsarticle/4655013/images/469992/large/2-amrc.jpg

regards,

Dan T