Vibration Absorbers

About Vibration Absorbers and Vibration Absorber Manufacturers Including: Bushings, Rubber Bumpers, Rubber Mounts, Shock Absorbers, Vibration Isolators & Vibration Mounts.

Vibration absorbers are shock reducing devices used to protect a wide range of machinery and equipment from noisy, damaging vibrations. Also referred to as vibration isolators, vibration absorbers provide vibration control and energy absorption in applications in which vibration or jarring motion are undesirable bi-products of equipment processes. Elastomeric rubber bumpers, or rubber mounts, are mounted between two pieces of machinery to prevent vibrations from transferring through metal-to-metal contact, such as engine mounts; bumpers, bushings and rubber pads are placed between the floor and vibrating equipment to both reduce the noise of equipment-floor vibrations and to eliminate the risk of equipment damage. Shock absorbers are another type of vibration isolator common in transportation and motion machinery; unlike vibration mounts, which are typically molded or extruded rubber, shock absorbers may be rubber, spring-loaded (mechanical) or hydraulic. Hydraulic shock absorbers tend to provide the most powerful protection from jarring shocks and vibrations, leading to their common application in motor vehicles and precision equipment.

Both consumer and manufacturing industries use vibration absorbers and vibration isolators to reduce noise and equipment damage. Cars, trucks and other moving transportation vehicles use nearly every type of vibration absorption available to protect numerous parts within the engine and vehicle chassis from vibration and shock damage. Rubber bumpers, rubber shock mounts and pillow blocks are placed between parts and the automobile body, while hydraulic shock absorbers and mechanical shock springs are placed between the wheels and the axles. Molded rubber engine mounts are particularly crucial because the engine is a large source of vibration, and the metal-to-metal vibrations between the engine and the car body would quickly damage the engine.

Consumer households and commercial laundry businesses place rubber pads beneath washing machines and dryers which are specially designed to absorb the motion caused by spin cycles, reducing equipment noise and giving laundry equipment longer life. Household air conditioners typically have some form of vibration isolation preventing vibration between the air conditioner and its window housing. Rubber or foam vibration absorbers are used simultaneously for vibration isolation and for soundproofing in audio equipment applications such as speakers and sub-woofers. Common automotive and industrial applications for vibration isolating rubber bumpers and rubber pads include railway cabins, industrial machinery, radiators, electronic equipment, welding equipment and vibratory finishing equipment.

Vibration absorption is a simple way to prevent equipment breakage and noisy operation. Rubber mounts, pads, bumpers, bushings and grommets are the simplest type of vibration isolation; with no moving parts, rubber vibration mounts made from the proper material with proper curing may last longer than the equipment they protect. Rubber vibration absorbers provide "dampening", a specific type of vibration absorption in which the kinetic energy from vibrations are absorbed by the rubber and diffused as heat. Natural and synthetic rubber materials such as butyl, EPDM, fluoroelastomer, nitrile, neoprene and silicone are used in vibration isolation applications requiring various characteristics of heat resistance, chemical resistance and hysteresis. Spring-loaded and hydraulic shock absorbers, being mechanical, can be more prone to part failure, although these typically can absorb far more physical shock than rubber mounts can. This makes hydraulic shock absorbers ideal for high-impact applications and rubber mounts cost-effective and ideal for applications with lower impact.

Vibration Isolation and Energy Absorption - Endine-ITT	Industrial Shock Absorbers - Endine-ITT

Types of Vibration Absorbers

• Air springs offer a favorable stroke-to-compressed-height ratio, when compared to air cylinders, and can accept a wide variety of actuation media, such as air, water, nitrogen or anti-freeze for use in a variety of vibration isolation applications.
  
• Bushings are placed between moving parts to absorb vibration.
• Cam followers are driven by circular motion. The cam follower traces the surface of the cam transmitting its motion to the required mechanism.
  
• Dashpots are absorption devices that use fluid to enact resistance. Once downward force is no longer being applied, the plunger-like device remains in position. Dashpots are used normally in small devices, such as instrumentation and precision manufacturing machinery.
  
• Engine mounts are vibration isolators placed between an engine and the structure that supports the engine, in order to reduce the effects of vibration, noise and shock encountered during engine operation.
  
• Helical isolators achieve attenuation of both shock and vibration and are made entirely of non-corrosive materials. Helical isolators are most commonly used for vibration and shock absorption in such industrial and commercial machinery as compressors, hammers, printing machines and other applications in which shock isolation is important to the effective and efficient running of the apparatus.
  
• Machinery mounts protect machines from vibrations emanating from within the equipment itself, as well as from other pieces of equipment. Machinery mounts are used on compressors, screw machines, pumps and generators.
  
• Rubber bumpers are commonly used in the automotive/trucking industry to protect vehicles and trailers through vibration and shock absorption.
  
• Rubber mounts are rubber components that isolate the vibration from moving parts.
• Rubber pads are vibration dampeners often placed between industrial equipment and the surface upon which the equipment rests. Rubber pads may have a ribbed pattern to prevent slippage.
  
• Shock absorbers use various methods to dampen vibrations caused by sudden motion and mechanical shocks.
• Vibration isolation mounts are rubber mounts used to protect a variety of industrial items, including engines, machinery and equipment components. Vibration mounts effectively reduce or eliminate oscillation.
  
• Vibration isolators are used to protect equipment by keeping the vibration of a component from spreading to the entire machine or work environment.
• Wire rope isolators consist of a metal cable configured in sets of strands. Wire rope isolators are used in applications in which exposure to chemicals, oils and high or low temperatures is common.

Vibration Absorbers Terms

Amplitude - Amplitude is the maximum value of a repetitively oscillating quantity (i.e. acceleration, displacement).
 
Damping - The reduction of oscillatory motion in a vibratory object through the loss of energy in the form of heat during vibratory cycles. Vibration dampers increase the amount of vibratory energy lost during an object's oscillatory motion, which decreases the vibration of the object.
 
Deflection - An indication of a vibration isolator's ability to provide vibration control. Deflection refers to the amount that an elastomer, such as a rubber mount, moves due to a force, such as vibration or shock.
 
Displacement - The movement of an object from its initial placement. Vibration is a common cause of displacement.
 
Elastomer - A material, such as rubber, that is capable of returning to its initial length after being stretched at room temperature to at least twice its original length.
 
Forced Vibration - The vibration of an object due to an applied force.
 
Fragility - A measurement representing the level of vibration to which an object can be subjected before sustaining damage.
 
Free Vibration - The occurrence of vibratory movement during an object's displacement without the application of an external force.
 
Frequency - The repetition of vibratory motion during a specified period of time.
 
Hertz - Also referred to as "cycles per second," it is a measurement of vibratory motion or frequency that occurs per second.
 
Impulse - The integral of force over a time interval.
 
Jerk - The rate of change of acceleration with time.
 
Natural Frequency - The number of cycles that an object freely vibrates during a given unit of time.
 
Periodic Motion - Motion that repeats itself at measurable intervals of time.
 
Resonance - An increase in the vibratory motion of an object that occurs when an object's natural frequency and the frequency of the force applied to an object are equivalent to one another. This frequency point is termed the resonant frequency.
 
Shock - A force to which an object is subjected that disturbs the object's stability, causing an imbalance of equilibrium. Shock is often isolated in conjunction with vibration to stabilize an object's equilibrium.
 
Steady State Vibration - Steady state vibration exists in a system, if the velocity is a continuous periodic quantity.
 
Transmissibility - The amount of vibration generated by an object that is transmitted to the object's support structure.