Email Address:
PBC Linear Company Logo
TOLL-FREE 1-800-962-8979
Dave Humblet

Simplicity Linear Bearing’s Self-Alignment Feature

July 14, 2011 - Rockford, IL  -  Posted by Dave Humblet

Self-aligning capability with regards to linear plain bearings refers to the ability to handle slight misalignments or shaft deflection.  Achieving perfect parallelism in a parallel shaft configuration is very difficult.  In addition, keeping all mounting holes in perfect alignment with the shaft adds to the challenge.  Simplicity bearings and pillow blocks that offer self-aligning capability can alleviate some of those challenges.

Simplicity linear plain bearings are able to achieve this self-aligning capability in one of two ways.  The FL/FM/FJ series of bearings are available with a straight cylindrical outside diameter (OD) as standard.  Also offered aSelf-aligning Linear Bearingss an option are the FLA/FMA/FJA series, and these all feature a crowned, or spherical, OD. 

  1. Use the standard straight OD bearings (FL/FM/FJ) with all standard Simplicity housings, pillow blocks, and flange mount housings.  These housings have the self-aligning capability designed into the inside diameter (ID), or bore.  This built-in feature provides up to ½ degree of self-alignment in all directions, allowing for some shaft deflection and misalignment.


      2.       Use the FLA/FMA/FJA series with the OD crown.  This crowned feature would be used where the mating housing bore is straight, such as a custom housing on the machinery, or a straight-bore pillow block.  This bearing configuration then offers the same ability for the bearing to rock/pivot within the bore and handle up to ½ degree of misalignment in all directions.

It is also important to mention a third configuration related to self-aligning capabilities, and that is the use of a straight OD bearing in straight bore housing.  This DOES NOT allow for any self-alignment and provides a very rigid assembly.  These are typically used in single shaft applications, and offer a solution where tighter repeatability and precision are required. 

NOTE:  Sometimes there is confusion between self-aligning feature and compensated fit of the bearing.  Please keep in mind that self-aligning refers to the OD of the bearing and ID of PBC’s standard housings.   The term “compensated” refers to the fit of the ID of the bearing to the shaft.  A bearing or pillow block can have both features (self-alignment and compensated ID), or neither one.  This concept will be discussed in a separate topic. 



blog comments powered by Disqus

Blog Posts:

Join Our Newsletter


Get our latest news and updates

Product Sample

Sign up for free product samples to evaluate with your application!

Product Sample
PBC Linear | 6402 Rockton Road, Roscoe, IL 61073 | P. O. Box 6980, Rockford, IL 61125-6980 | Toll-Free (800) 962-8979 | Fax: (815) 389-5790

© PBC Linear - A Pacific Bearing Company | All Rights Reserved.

Site Map | Contact Us | Terms & Conditions | Purchase Order Terms | Privacy Statement | Return Goods Policy | ROHS Certification | India Steel | Conflict Minerals