Environmental Engineering Reference
In-Depth Information
Discharge
Packing
gland
Radial
bearing
hrust
bearing
Shaft
Suction
Impeller
wear ring
Pump
frame
Slinger
ring
Stuffing
box
Impeller
Volute
figure 3.7 Major components of a centrifugal pump.
3.3.2 Terminology
To understand centrifugal pumps and their operation, we must
understand the terminology associated with centrifugal pumps:
Base plate
—The foundation under a pump. It usually extends far
enough to support the drive unit. The base plate is often referred to
as the
pump frame
.
Bearings
—Devices used to reduce friction and allow the shaft to
rotate easily. Bearings may be sleeve, roller, or ball.
•
radial (line) bearing
—In a single-suction pump, it is the one
closet to the pump. It rides free in its own section and takes up
and down stresses.
•
Thrust bearing
—In a single-suction pump, this is the bearing
located nearest the motor, farthest from the impeller. It takes
up the major thrust of the shaft,
which is opposite from the dis-
charge direction.
Note:
In most cases, where pump and motor are constructed on a common
shaft (no coupling), the bearings will be part of the motor assembly.
Casing
—The housing surrounding the rotating element of the pump.
In the majority of centrifugal pumps, this casing can also be called
the
volute
.
•
Split casing
—A pump casing that is manufactured in two pieces
fastened together by means of bolts. Split casing pumps may be
vertically split (perpendicular to the shaft direction) or horizon-
tally split (parallel to the shaft direction).
