Understanding vibration isolation
Before you can really understand vibration isolation, you need to understand the causes of vibration. This can be attributed to multiple factors, including mechanical imbalances like uneven mass distribution in rotating components and external forces such as impacts. Resonance occurs when external vibrations align with a system's natural frequency, amplifying the effect. Operational forces from machinery, repetitive loading, and material characteristics such as stiffness and damping play significant roles as well.
Consider, too, that electromagnetic forces in motors and fluctuations in load during operation contribute to vibrations. Recognising these causes is crucial for effectively managing vibration isolation in mechanical systems.
In this guide, we’ll explain what you need to know about vibration isolation, including:
What is vibration isolation?
Types of vibration isolation systems
Why is it important?
What are the causes of abnormal vibration?
How to isolate vibration
Types of vibration isolation products
What is vibration isolation?
Vibration isolation minimises or completely eliminates the transmission of vibrations between surfaces or objects. At its core, vibration isolation relies on several key principles and mechanisms to achieve effective damping of vibrations:
1. Absorption of vibrational energy
Isolation systems use materials or devices that absorb vibrational energy, converting it into heat or dissipating it through movement. Common materials include rubber, foam, and elastomers, which can deform under stress, reducing the energy transmitted to the structure or machinery.
2. Decoupling
Vibration isolation often involves decoupling the source of vibration from the receiving structure. This can be achieved through flexible mounts or isolators that allow movement in response to vibrations, thereby reducing direct contact and energy transfer.
3. Spring systems
Springs are widely used in vibration isolation. They allow for controlled displacement when subjected to dynamic loads, effectively reducing the amplitude of vibrations passed on to the isolated structure. By carefully selecting spring stiffness and load capacity, engineers can design systems tailored to specific vibrational frequencies.
4. Damping mechanisms
Damping is critical in controlling oscillations. Various damping techniques, such as
viscous or friction damping, are employed to dissipate energy quickly. Damped
systems are designed to reduce the magnitude and duration of vibrations, preventing prolonged oscillation that could lead to damage or discomfort.
Types of vibration isolation systems
Vibration isolation can be categorised into two main types:
● Passive vibration isolation
These systems do not require external energy or control systems to function. Instead, they rely on the properties of materials and the arrangement of mechanical components. Examples include rubber mounts, springs, and isolators that can absorb and dissipate vibrations based on their inherent properties.
● Active vibration isolation
Active systems use sensors and actuators to detect vibrations and respond in real-time. These systems actively counteract vibrations by applying forces opposite to those generated by the source. This type of isolation is often found in sensitive equipment, such as precision instruments or spacecraft, where maintaining stability is crucial.
Why is it important?
Vibration isolation is vital for protecting equipment, enhancing performance, ensuring safety, reducing noise, and improving comfort. Its application across various industries underscores its significance in maintaining operational efficiency and reliability, making it an essential consideration in design and engineering processes.
1. Protect equipment
● Damage prevention: Machinery and equipment are often sensitive to vibrations, which can lead to wear and tear or catastrophic failure. Vibration isolation helps to prevent such damage by reducing the energy transmitted from vibrational sources.
● Extended lifespan: By minimising vibrations, isolation systems can extend the operational life of equipment and machinery, resulting in lower maintenance costs and reduced downtime.
2. Improve performance
● Operational efficiency: Vibration can adversely affect the performance of machinery and instruments. For example, precision instruments require stability for accurate measurements. Vibration isolation solutions ensure that these instruments function optimally.
● Improved quality: In manufacturing, vibrations can lead to defects in products. By isolating machine vibration, companies can maintain higher quality standards and reduce rejection rates.
3. Safety
● Worker protection: Excessive machine vibration can lead to health issues like hand-arm vibration syndrome (HAVS) and other repetitive strain injuries for workers. Vibration isolators help minimise these risks, promoting a safer workplace and reducing the likelihood of injuries.
4. Noise reduction
● Minimising acoustic impact: Vibration often translates into noise, which can be disruptive in both industrial and residential settings. Effective vibration isolation helps to reduce noise pollution, creating a more pleasant environment.
5. Energy efficiency
● Reduced energy consumption: Machinery operating with high vibrations often requires more energy to maintain performance. Isolate vibration, and machines can operate more efficiently, leading to energy savings and reduced operational costs.
What are the causes of abnormal vibration?
We touched on this earlier, but let’s take a deeper look. Vibration is a mechanical phenomenon characterised by oscillations or repetitive motions of an object around an equilibrium position. That’s the technical definition. It can be caused by various factors, which can be grouped into several categories:
1. Mechanical imbalances
● Rotational imbalance: In rotating machinery, uneven distribution of mass (such as in a rotating shaft or wheel) can create centrifugal forces that lead to vibrations.
● Misalignment: When components are not properly aligned – think of shafts and gears – they can cause excessive wear and vibrations during operation.
2. External forces
● Impact loads: Sudden forces applied to a system, such as drops, collisions, or strikes, can induce vibrations.
3. Resonance
● Natural frequencies: When external vibrations match the natural frequency of a structure or system, resonance can occur, amplifying vibrations significantly.
● Harmonic excitation: Systems subjected to periodic forces can vibrate at frequencies that are multiples of the excitation frequency, leading to resonance conditions.
4. Dynamic forces and operational changes
● Operational forces and load variations: Equipment in operation, such as engines and pumps, can generate vibrations from moving parts, load fluctuations, and speed changes, especially during start-up or shut-down cycles.
● Cyclic loading: Repeated loading and unloading of materials, as seen in fatigue testing, can cause them to vibrate over time.
● Fluid dynamics in systems: Fluid fluctuations, including cavitation in pumps or turbulence within pipes, can also produce vibrations, especially in systems where fluid stability is critical.
5. Material properties
● Stiffness and damping: Vibration-isolation materials offer properties, such as stiffness (resistance to deformation) and damping (energy dissipation), which influence how vibrations propagate. Materials with low damping transmit vibrations more effectively than those with high damping.
6. Environmental factors
● Temperature fluctuations: Changes in temperature can cause thermal expansion or contraction, leading to mechanical stresses and subsequent vibrations.
7. Electromagnetic forces
● Electromechanical systems: In electric motors or generators, electromagnetic forces can induce vibrations, particularly if there are harmonics or unbalanced currents.
How to isolate vibration
Effective vibration isolation requires a systematic approach to ensure the chosen solution meets the specific demands of the equipment and machinery. Each step is essential for reducing vibration transmission. We’ve outlined key steps for achieving reliable vibration isolation:
How to reduce vibration in machines
Step 1: Assessing vibration sources and requirements: Identify where the vibrations are coming from, the type and frequency of vibrations, and the specific requirements for isolation based on the equipment or environment.
Step 2: Choose isolation methods and materials: Based on the vibration assessment, select suitable isolation devices, such as rubber mounts, springs, damping materials, or active isolation systems.
Step 3: Implement the vibration isolation product: Install the chosen isolation method correctly, following any design specifications, and making adjustments as necessary.
Step 4: Test and Adjust: Measure the effectiveness of the isolation system after installation and making any necessary adjustments to improve performance.
We also urge you to check out the guide our experts have put together, How to prevent HVAC vibration.
Types of vibration isolation products
Our range of vibration isolation solutions are available to manage and reduce vibrations in equipment and machinery, from lightweight appliances to industrial machines. Each product type is crafted for specific uses, helping to enhance stability, reduce noise, and improve the lifespan of your equipment.
Anti-vibration mounts
Ideal for machine vibration isolation, both of these rubber anti-vibration components serve as buffers, specifically designed to absorb vibrations and minimise noise. Our range includes vibration-mount grommets and standoffs, ideal for preventing movement in stationary machinery.
Our spacers and vibration-isolation mounts act as shock absorbers, while contributing to noise reduction.
Rubber standoffs, or quiet mounts, are industrial vibration isolators, essential for isolating vibration and reducing noise in heavy-duty stationary machinery. These versatile components are also ideal for applications like washing machines and conveyors.
You can learn more in our expert Guide to anti-vibration mounts.
Anti-vibration buffers
Anti-vibration buffers are constructed from zinc-plated steel and rubber, offering durability and effective vibration dampening. They are available in various conical styles and a wide range of thread sizes to suit diverse applications.
Anti-vibration cylinders
Designed to absorb shocks, dissipate vibrations, and reduce noise, enhancing equipment performance, reliability, and lifespan. Used in machinery, compressors, air conditioning units, and light engineering, they should only be mounted under even loads in axial or radial directions, never in tension.
KPR damping mounts
Engineered with a durable galvanised steel ST37 casing and natural rubber components, offering a rubber hardness of 60 Shore. The range includes break-safe options and comes in various styles and thread sizes to suit different applications.
Push-fit bumpers and rubber feet
Push-in bumpers are versatile components used for damping vibration in a range of applications. Designed to serve as glides, bumpers, closures, slides, and stops, they protect surfaces from impact and reduce noise. The rubber bumper feet feature a push-in stem that securely holds them in place, preventing direct contact with surfaces. Available in a range of materials and styles.
Sandwich and stud mounts
Constructed from zinc-plated steel and rubber, these mounts are ideal for applications requiring vibration isolation. They can be used in compression, shear, or a combination of both, provided fail-safe functionality is not required. Available in five variants and a range of thread sizes to suit diverse needs.
Heavy-duty anti-vibration mounts
Heavy-duty. screw-on vibration mounts absorb shock and reduce noise, providing a secure and stable base for machinery and conveyors. Made of thermoplastic elastomer (TPE), these industrial vibration isolators are Ideal for heavy machinery, HVACs, generators, and compressors.
Stud mount levelling feet
These adjustable feet with a plastic rigid base are designed to adjust to uneven surfaces, making them ideal for levelling machine tools, electronic racks, and similar applications. The plastic base can also act as a buffer between the machinery and floor to help isolate vibration. For best results, use with anti-vibration mounts. The plastic base also ensures a smooth, non-abrasive surface that protects floors from damage.
Sealing gaskets
Clip-on profiles provide edge protection and sealing for metal sheets. They isolate vibration and shield the metal from humidity, and dirt, providing an extra layer of protection for enclosure boxes.
Compression cam latches and locks
Our compression latches and locks are designed to provide superior machine vibration isolation. When closed, the latch compresses the gaskets against the door and panel openings, creating a tight seal that effectively dampens vibrations and noise, while protecting against environmental factors. Our wide range also includes latches with IP65, IP69 and NEMA ratings.
Our experts explain more in our Guide to compression latches and locks.
Download free CADs
Free CADs are available for most solutions, which you can download. 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 dispatch.
Questions?
Email us at sales@essentracomponents.co.uk or speak to one of our experts for further information on the ideal solution for your application 0345 528 0474.