Page 172 - Know and Understand Centrifugal Pumps

Bearings

Introduction

In order to understand bearings and their application in the world of
pumps, it’s best to consider some of the fundamentals and terminology
of bearings. Pump bearings have two general classifications: sleeve
bearings and rolling element bearings. The sleeve bearing is used mostly
on reciprocating rods and shafts and on some low rpm rotating shafts.
For rotating and centrifugal pump shafts the rolling element bearings
have almost displaced the older sleeve type bearings. The precision
rolling element bearing may have round balls, or rollers in the form of
spindles, cones, or needle rollers as the rolling elements. The rolling
elements move within an inner ring or race and an outer ring or race.
With pumps, the inner ring mounts onto, centers, and rotates with the
spinning shaft. The outer race is stationary and seated into a bore in the
bearing housing. This arrangement may be reversed in some special
duty pumps.

TYPE DESCRIPTION
Ball Bearing - Conrad Deep Groove This is a single row bearing. It can
handle moderate radial and axial loads
from any direction.
Ball Bearing - Heavy Duty This is also a single row design, but it
has more balls in the assembly than the
Conrad bearing.
Ball Bearing - Double Row, not self-aligning. These bearings have two rows of balls
and can handle 50% more radial load
than the Conrad type bearing.
Alignment is critical.

155