Taper roller bearing mouning configurations

[k.udhay]

Hello,

I see that the TRBs (Taper Roller Bearings) are paired usually in 'X' or 'O' configuration. Can somebody pl. share the situations that drive towards choosing a specific configuration? Thanks.

 

[Baluncore]

Basically the “X” best fixes the axial position and alignment so it is used in situations such as vehicle stub axles and machine tool headstocks where axial stability is critical.

The “O” configuration is not alignment critical since the bearing surfaces can be arranged to be tangent to the surface of a virtual sphere. This positions the shaft axially but it can tolerate significantly more misalignment than the “X” configuration. When the shaft weight must be carried but the bearing need not be in a precisely aligned housing the “O” configuration is used.

 

[k.udhay]

Hi Baluncore - I am very sorry for a delayed reply. Thanks for your answer. Can you pl. explain me this:
//The “O” configuration is not alignment critical since the bearing surfaces can be arranged to be tangent to the surface of a virtual sphere//
I am unable to understand what is meant by arrenging to be tangent to the surface of a virtual sphere... Thanks.

 

[Baluncore]

Does the attached image explain it ?
The "O" configuration on the left. The "X" on the right.

 

[k.udhay]

Thank you very much Baluncore... The image was really self-explanatory...! I caught the idea... Thanks again!

 

[k.udhay]

//The “O” configuration is not alignment critical since the bearing surfaces can be arranged to be tangent to the surface of a virtual sphere//
I think it is the 'X' configuration that can ge arranged to be the tangent to the surface of a virtual sphere? I take image 'a' as 'X' configuration... Am i right?

 

[Baluncore]

The effective TRB “bearing surface” is defined by “roller axis”.
The “bearing surface” is perpendicular to the loading forces.

It comes down to the original convention used to define roller orientation.
The "X" and the "O" configurations are defined by roller axis. NOT by the roller load forces.

See this attached image. From; Fundamentals of Machine Design. Vol 4, p305. P.Orlov. 1977.

 

[k.udhay]

Obviously I am wrong then... I remember I found this other way of defining 'X' and 'O' configuration in a catalogue. Thanks a ton Baluncore! :)