3
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Fan Application No. FA/103-00
Greenheck Product Application Guide
locations on the shaft; thrust loads; and the
direction of belt pull. Most often the selection
program used is one developed by a bearing
manufacturer. Greenheck engineers use Dodge
bearing selection software. Based on the output
results of this data, Greenheck engineers are able to
select the bearings that best meet each individual
application.
Light duty bearings
Ball bearings with stamped steel housings are well
suited for applications with very light loads and
lower speeds. The main design characteristic that
defines stamped
bearings is the rubber
sleeve around the
bearing insert, which
snaps into the
stamped housing. The
use of these bearings
is limited to fan
products with 3⁄4 inch
and smaller diameter
shafts, and one
horsepower and smaller motors.
Air handling quality
When the operating level of the ball bearings with
stamped steel housing is exceeded, air handling
quality ball, spherical or tapered roller pillow block
or flange-mount bearings are primarily specified.
These bearings have been engineered specifically
for air handling applications and feature special
construction and tighter quality control. In order for
a bearing to be of “air handling quality,” it must
meet the following specifications:
1. Reduced swivel torque
Proper alignment of the bearing to the shaft is
essential in preventing vibration, noise and damage
to the bearing components. To allow a bearing to
self align under light loading, it must have a low
swivel torque. A low swivel torque enables the
outer race of the bearing to pivot or swivel within
the cast pillow block, allowing the bearing to align
to the shaft much easier. It should be noted that this
feature is special only to air handling ball bearings
and tapered roller bearings. Spherical designs
inherently allow for easy self-aligning because the
race has a radius that allows the rollers to pivot
somewhat within the race, so the race doesn’t need
to pivot within the pillow block.
2. Noise and vibration testing
All “air handling quality” bearings are 100%
vibration tested. These high test standards are
designed to discover microscopic manufacturing
defects that may either cause higher noise levels or
lead to premature failure of the bearing.
3. Bore Size Test
All “air handling quality” bearings are 100%
inspected to insure that the inner race diameter is
within tolerance. A bore size larger than tolerance
would allow the bearing to shift which could cause
misalignment.
The benefits of “air handling quality” bearings to
the life of ventilation equipment are being seen
throughout the HVAC industry. More and more
manufacturers are providing air handling quality
bearings as their standard.
Ball bearings
The Dodge D-Lok pillow block bearing
incorporates a “heavy-clamp-style” locking collar as
an alternative to the typical set screw locking
system. This design allows the bearing race to be
tightened concentrically about the shaft. This type
of locking mechanism gives two distinct advantages
over the set screw method. First it maintains one
common center axis of the shaft and bearing,
whereas tightening of the set screw forces the shaft
off to one side, offsetting its rotating axis. Secondly,
the shaft and bearing race come into surface-to-
surface contact upon tightening. This increase in
contact surface area not only improves the holding
strength of the bearing to the shaft, but it also
eliminates problems with burring on the shaft
caused by the tightening of set screws.
Application
Greenheck uses Dodge
D-Lok ball bearings for
all centrifugal, vane
axial and industrial
units within the ball
bearing application
range. In our fan and
ventilation line, Dodge
D-Lok ball bearings are
Ball Bearing with rubber sleeve
and stamped steel housing.
Ball bearing with D-Lok
