Unbalanced: When a substantial mounting structure
or foundation exists, vibratory equipment can be
operated without a counteractive force.
Balancer Driven: Some manufacturers offer a vibratory design where
a transport surface is mounted to a weighted balanced frame using a
reactor spring assembly, and the weighted base is isolated from the
ground using isolation springs. The vibrating motor or drive on this type
of conveyor is mounted to the balancer, and does not directly drive the
transport surface. There are signifcant flaws in the physics of this design.
For one, the natural frequency of the suspension system is typically around
50 percent of the operating speed of the motor. If the motor speed is
reduced, this will cause the vibratory unit to approach the natural frequency
of the suspension system, causing erratic operation. Another problem with
this design is that it does not respond positively to changes in material
weight, so the effect of balancing on this type of isolation is only around
60 to 65% effective.
This design is also more likely to lose conveyability if
the transport surface is overloaded with product. General Kinematics does
not recommend this type of vibratory conveyor for these reasons.
A-Balanced: "A" balanced conveyors typically have a counterpoise frame
equal to the trough weight supported on the conveyor base by duplicate
trough reactor assemblies, and is positively driven 180 degrees out of
phase with the transport surface.This results in an equal and opposite
reaction along the rigidly mounted base of the conveyor.
B-Balanced: "B" balanced conveyors are similar to design A, except that
the entire conveyor is mounted on a floating spring - mounted sub-base
for the ultimate in isolation effciency.
C-Balanced: A "C" balanced unit uses a weighted frame isolated from the
mounting surface by springs. The base is typically four times heavier than
the weight of the transport surface above, and the heavier the base, the
greater the isolation it provides.
During operation, this weighted lower
base runs 180 degrees out of phase with the transport surface,
counteracting the forces generated above. This design oers high isolation
effciency with maximum economy for many applications.
D-Balanced: A "D" balanced vibratory device is comprised primarily of two separate
and distinct masses, one designed to carry material and the other mass designed to
offset dynamic loads that would normally go into a structure. These two masses
normally run 180 degrees out of phase so that they cancel forces or minimize forces
going to the earth.
The design is different than other types of balanced conveyors in
that the balancer reacts positively to material load which changes the dynamic
characteristics. This positive reaction more closely isolates or cancels the vibratory forces of the transport mass. This design is ideal for structures or situations with a poor or light
grounding structure, and are 90 to 96% effcient in eliminating vibration into the ground.
In rare circumstances where absolutely no vibration transfer is acceptable, this design
can also be isolated from the ground, and is the most effective balancing design available. |