Dynamically Balancing Vibratory Equipment.
Why should you balance your vibratory equipment?
You should balance your vibratory equipment to significantly reduce the transmission of vibratory forces from the machine to the surrounding environment.
When should you balance your vibratory equipment?
You should balance your equipment whenever equipment is installed on elevated support steel, on large floor spans, upper stories, on soft ground, or areas with a high water table.
What is “balancing”?
Balancing is the application of Newton’s third law of motion, that for every action there is an equal and opposite reaction. By moving one mass of the machine (let’s say, the trough of a conveyor, for example) in the opposite direction of another mass (an equally heavy balancing weight), you essentially balance the forces created by both masses. However, factoring in material load complicates things. This is where GK’s engineering team comes in to play.
What do GK balanced machines look like?
Unbalanced: When a substantial mounting structure or foundation exists, vibratory equipment can be operated without counterbalancing.
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 efficiency.
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 offers high isolation efficiency 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.
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 significant flaws in the physics of this design.
One issue with this design is 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.
