A guide to anti-vibration mounts
Choosing anti-vibration dampers
Anti-vibration mounts should always be considered as one of your HVAC components or industrial generator parts, and not only large machinery. Even fans in computers create vibration, so you need to think about protection for data cabinets, appliances and computers.
In this guide, we’ll help you choose anti-vibration mounts. We’ll cover:
The bottom line is, if it vibrates, it can wreak havoc.
Vibrations can cause:
- 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
- Shortened lifespan of machine
These reasons are why anti-vibration solutions are so important.
Anti-vibration mounts are made of rubber or a combination of rubber and other materials. The advantage to combining rubber with say, steel, is that it enables easy mounting and provides a durable solution to effective vibration absorption. They’re fastened to your machine and can be used for compression. When your machine is being used, the mounts absorb and dampen vibration, significantly minimising the impact of vibration, such as noise.
If a motor, fan or any other moving part is involved, vibration really cannot be prevented. It can be controlled, which is the job of an anti-vibration mount. It’s an extremely cost-effective solution. 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 Types of generators and how they compare and Quick guide: components for your industrial generator.
They fasten to the application – usually on the bottom – and absorb 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.
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 75 Shore A
Used for: Heavy machinery, HVAC, generator vibration mounts, and anti-vibration mounts for air compressors
Machine mounts – anti-vibration feet
- Good adhesion to the floor
- Unique design enables height adjustment while maintaining a totally sealed vibration-absorbing base
- Screw on
- Cast iron base with nitrile rubber moulding 80 Shore
Used for: Anti-vibration mounts for diesel generator, conveyors and other machinery
- Heavy-duty anti-vibration mounts – female
- Screw-on rubber-and-bumper vibration damping feet
- Steel and rubber 50 Shore A
Used for: Generator rubber mounts and for other heavy machinery
- Acts as an anti-vibration cushion between two parts to absorb vibration
- Both male/male and male/female styles available
- Operating temperature range: -40˚C to 90˚C
- Neoprene rubber 40 Shore and steel
Used for: Flight controllers, machinery, generators, HVAC blower motor compartments
- Steel and rubber mount studs
- Also known as vibration damping sandwich mounts
- Can be used in compression, shear or both, where there are no requirements for fail safe functionality
Used for: automotive, healthcare and agriculture equipment
- Ideal for stationary machinery that can’t avoid movement
- Flexibility to help vibration and noise damping
- Neoprene rubber 60 Shore A
Used for: Assemblies within electronics
- Used with vibration grommets
- Operating temperature range: -40˚C to 50˚C
- Zinc-plated carbon steel
Used for: HVAC blower motor compartments, electronics
- Takes vertical load applied in both shear and compression to isolate vibration
- Features galvanized steel ST37 and natural rubber moulding 60 Shore
- Ideal for mobile applications
Used for: Generator sets and transit equipment
- Conical profile provides a progressive force typical of applied shock deflection
- Zinc-plated steel and rubber 60 Shore A
Used for: Vehicle suspensions, off-road vehicles and handling equipment, i.e., forklifts
Vibration mount standoffs, also called stud mounts, are often made of rubber and steel, and prevent excessive vibration. These act as a cushion and are sandwiched between two parts. They have a threaded metal insert and are available as male/male or male/female.
Vibration mounts can:
- Reduce installation time
- Increase time between maintenance
- Extend machinery’s lifespan
- Reduce annoying vibration and transmitted noise
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 a durable solution to effective vibration absorption. 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 minimising 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, which can be a synthetic or natural material, 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|
|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|
|200 – 3,500 PSI
|20-95 Shore A
Elastomers for vibration isolation
Natural rubber and 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:
|Oils and Greases||Excellent|
Follow these steps to determine not only the anti-vibration machine mounts you’ll need, but also the number and size required for your application.
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 for free. You can also request free samples to ensure the solutions you’ve chosen are exactly what you need. If you’re not quite sure which product will work best for your application, our experts are always happy to advise you.
Email us at firstname.lastname@example.org or speak to one of our experts for further information on the ideal solution for your application 0345 528 0474.