A guide to anti-vibration mounts
Choosing anti-vibration dampers
Anti-vibration components should always be considered as one of your HVAC components or industrial generator parts, and not only for large machinery. Even fans in computers create vibration, so you need to think about protection for data cabinets, appliances and computers. Anti-vibration mounts can be known by many other names such as vibration isolators and vibration isolation mounts.
In this guide, we’ll help you choose anti-vibration mounts. We’ll cover:
Why anti-vibration support is so important
Vibration can create havoc:
- Damage to machine parts
- Loosening of screws and bolts
- Loss of production
- Transmitted noise, which can travel throughout a building
- Damage to floors
- Malfunctions with sensitive and accurate equipment
- Operator discomfort
- The shortened lifespan of the machine
If a motor, fan or any other moving part is involved, vibration transmission really can not be prevented. It can be controlled, which is the job of an anti-vibration mount. It’s an extremely cost-effective solution designed to reduce noise and reduce vibration. . Think of a generator and the potential damage vibration can cause. Vibration dampers for machines prevent those problems from occurring. You might find it helpful to check out the Types of generators and how they compare and Quick guide: components for your industrial generator.
How do anti-vibration mounts work?
They fasten to the application – usually on the bottom to provide vibration control. Once applied to the application, they will work to protect equipment, limit noise and vibration and help to limit the excessive noise that can be caused by vibrations.
What material absorbs vibration the best? This is critical, of course. Typically, the best vibration damping material is rubber, or thermoplastic elastomer (TPE), a family of rubber-like materials. We’ll take a closer look at materials further on but first, let’s explore types.
Types of anti-vibration mounts
The most common anti-vibration dampers are popular for good reason: they’re effective at reducing vibration, shock and noise. You’ll notice the term “Shore” when describing the material. If you’re not familiar with the meaning, check out What’s shore hardness and why should you care?
Here are common examples of anti-vibration mounts for machines:
- Good adhesion to the floor
- Screw-on damping mounts
- TPE Shore 75 A
Used for: Heavy machinery, HVAC, generator, vibration mounts, and anti-vibration mounts for air compressors
- Acts as an anti-vibration cushion between two parts to absorb vibration
- Both male/male and male/female styles available
- Operating temperature range: -40˚F to 176˚F
- Neoprene rubber Shore 40 and steel
Used for: Flight controllers, machinery, generators, HVAC blower motor compartments
- Ideal for stationary machinery that can’t avoid movement
- Flexibility to help vibration and noise damping
- Neoprene rubber Shore 60 A
Used for: Assemblies within electronics
- Used with vibration grommets
- Operating temperature range: -40˚F to 122˚F
- Zinc-plated carbon steel
Used for: HVAC blower motor compartments, electronics
Which materials absorb vibration?
As already mentioned, TPE and rubber are excellent materials for absorbing vibration. The benefits to mounts made of these materials are below.
Rubber anti-vibration mounts
Rubber vibration dampers often contain another material, such as steel. The advantage to this is that it enables easy mounting and provides durability. They’re fastened to your machine and can be used for compression. When your machine is in use, rubber mounts absorb and damp vibration, significantly minimizing the impact of vibration and noise.
Natural rubber is resistant to abrasions and low temperatures, but it has poor resistance to petroleum-based fluids. Nitrile is a synthetic rubber, and this is the most common material used to make rubber mounting.
Rubber, whether synthetic or natural, possesses long-coiled, high-molecular-weight chains. These chains are cross bridged with specific chemicals to form a network. The result is a material that can accept and recover from extreme deformation of 200% or more.
Generally, Nitrile material offers:
| Resistance to weather and UV rays | Poor |
| Water resistance | Good |
| Chemical resistance | Excellent |
| Tear resistance | Good to excellent |
| Resistance to gas permeability | Very good |
| Resistance to ageing due to steam | Fair to good |
| Compatibility with ketones | Poor |
| Compatibility with alcohols | Fair to good |
Generally, Nitrile material has:
| Temperature Range | -40°C to 100°C /-40°F to 210°F |
| Tensile Strength Elongation |
200 – 3,500 PSI 350%-650% Maximum |
| Durometer Resilience/Rebound |
20-95 Shore A Good |
Elastomers for anti-vibration mounting
Synthetic materials that mimic rubber are elastomers. What you’re looking for is a balance of properties. You should understand how they affect each other. It might be that you need to reduce a characteristic of one material to strengthen the characteristic of another.
Vibration mounts, which act as feet on machinery and conveyors, are often made of Thermoplastic Elastomers (TPE). The advantage of TPE is that is that it’s one of the most effective materials for vibration damping.
It has good tear and abrasion resistance, TPE also has excellent flexural fatigue resistance and high impact strength. Because of its outstanding electrical properties, it’s an ideal solution for applications involving electronics or equipment.
Generally, TPE material offers:
| Tensile Strength | 0.5 – 2.4 N/mm² |
| Notched Impact Strength | No break Kj/m² |
| Thermal Coefficient of expansion | 130 x 10-6 |
| Max Cont Use Temp | 140˚C / 284˚F |
| Density | 0.91 – 1.3 g/cm3 |
Resistance to chemicals:
| Dilute Acid | Excellent |
| Dilute Alkalis | Excellent |
| Oils and Greases | Excellent |
| Aliphatic Hydrocarbons | Excellent |
| Aromatic Hydrocarbons | Poor |
| Halogenated Hydrocarbons | Poor |
| Alcohols | Excellent |
How to choose vibration damping mounts
Step 1: What’s the machinery’s weight?
This will give you an idea of how many mounts you’ll need, or the size of those mounts. The heavier the machine, the larger the mounts – or number of mounts – will be required.
Step 2: What’s the weight of the mounts you need?
Let’s say your machine weighs 800 lbs. and you’ll be using four mounts. If the weight of the machine is distributed equally, you’ll want mounts weighing 200 pounds each. If the machine’s weight is not distributed equally, you’ll want heavier mounts where it’s needed.
Step 3: What is the machine’s RPM (repetitions per minute)?
Measure the machine’s speed. If you’re designing the machine, you’ll know what its RPM is.
Step 4: What is the machine’s static deflection?
This is how much your mount will compress under the weight of the machine. Using the chart below, let’s return to your machine that weighs 800 lbs, including the fan. Your degree of vibration isolation is 85%. Let’s now say the machine’s fan works at a speed of 1400 RPMs. Draw a line on the chart starting at 1400 RPMs and go across until you hit the 85% diagonal line. Now draw the line straight down. You’ll land on 3.5mm at the bottom. That’s your static deflection.
Step 5: Which mounting type?
Based on all the information you now have, you can choose the mounting type and dimensions that gives you the static deflection you need.
Download free CADs and try before you buy
Free CADs are available for most solutions, which you can download. You can also request free samples to make sure you’ve chosen exactly what you need. If you’re not quite sure which solution will work best for your application, our experts are always happy to advise you.
Whatever your requirements, you can depend on fast despatch. Request your free samples or download free CADs now.
Questions?
Email us at sales@essentracomponents.com or speak to one of our experts for further information on the ideal solution for your application 800-847-0486.