• # The Problem with Worn Suspension Bushes

Suspension bushes are a type of vibration isolator that is often made of rubber. The purpose of a suspension bush is to prevent metal-to-metal contact while still allowing for some movement. The movement is essential for allowing parts of the suspension to move freely. Although small, suspension bushes largely influence the efficiency of a vehicle, playing an important role in the safety, comfort, and handling of a vehicle. Because of this, it’s important to make sure your suspension bushes are up to scratch and not worn down.

• # Step By Step Guide To Choosing Anti-Vibration Mounts

With so many anti-vibration mounts on the market, it’s hard to know which is the best for your machinery to ensure smooth running, prolong lifespan and reduce the risk of damage. Machinery vibration from equipment can be transferred to the supporting structure and travel large distances to be emitted as noise elsewhere in a building or structure. Rubber mounts prevent the transfer of these vibrations the machines generate. As a leading specialist in anti-vibration mounts, we offer our extensive expertise using a step by step guide to help you choose the correct rubber mounts.

1. #### Identify the total weight (kg) of the equipment/machinery and the number of mountings that’ll be required.

The larger the total weight, the larger the mountings or the higher the number of mountings needed to reduce the machine vibrations.

1. #### Calculate the weight of each mounting. Make sure to consider that the weight on the machinery may not be evenly distributed.

For example, if the machinery weighs 340 kg, the equipment would require rubber mounts with a weight of 85 kg each if 4 mounts were purchased to evenly distribute the weight. Check the center of gravity to ensure an even distribution of load as different mounts may be required in different locations.

1. #### Measure the running speed of the machinery.

Calculate the normal running speed of the machinery, referred to as the forcing frequency and also the lowest operating speed (normally at idle).

1. #### Determine the static deflection of the mounting.

Static deflection is simply the amount that a mount compresses under the weight of the equipment. The more static deflection, the more work the mount has to do. For example, if a spring is 10 cm high when unloaded and compresses to 9 cm when carrying the weight of the equipment the static deflection is 1 cm.  This is how static deflection is calculated.

1. #### Based on the load per mounting, select a suitable mounting type to give the required static deflection.

Take into account specific application requirements and the reduction in vibration required. Graphs showing vibration isolation against deflection can be used to determine the levels of vibration reduction – contact us for guidance/details.

2. #### Ensure all connections and services to equipment, like the exhausts, pipework and ducting are flexible in order for the machinery to move freely.

Anti-vibration mounts have a number of benefits and offer great overall value for money. They not only serve to protect the machinery by reducing the impact of machines power, but also benefit the life of equipment, vehicles and structures. Without rubber mounts on the machinery, the sheer impact of the vibrations can cause weakening and even result in failure. It is therefore crucial to not only protect your equipment but also the well-being of the workers using the machinery with suitable mountings. The mounts are easy to install and are available in a variety of sizes, designs and load capabilities.

We have a number of trusted advisers who can help you with finding the best mounts anti-vibration mounts for your requirements. If you do need further guidance call us on 01943 870670 or browse our high quality range of anti-vibration mounts.

• # What is Finite Element Analysis?

Finite Element Analysis (FEA) is a computerised technique that predicts how products and materials will react to forces in the real world, alongside other physical affects, vibrations, heat, and fluid flow. This is important as it demonstrates whether a product will work or fail, helping prevent any products from being produced if they aren’t going to actually work.

### How Finite Element Analysis Works

For this Finite Element Analysis to work, it is necessary to break down an object into thousands of smaller constituent parts often referred to as ‘finite elements’. In general, the more elements there are the finer the ‘mesh’ and the more accurate the model and results will be. With the use of complex mathematical equations, it is possible to accurately predict how the product will react to different simultaneous inputs. Thanks to advances in computer software and computer processing power these calculations can be carried out using this method accurately and quickly.

### Importance of Finite Element Analysis

This method helps companies to save time and effort, while also improving the quality of their products. Carrying out Finite Element Analysis is important in many industries as it helps to improve their efficiency and prevents costly mistakes. Without the use of this method, there is the risk that products will not perform as they are intended to.

### Advantages of Finite Element Analysis

There are numerous benefits to the method of FEA. This process allows for the safe simulation of conditions that may otherwise be dangerous or difficult to replicate in a physical test environment.

The results produced by FEA software are extremely detailed and accurate, and offer a wide variety of conditions to be tested out. This helps to ensure the safety and efficiency of each product produced. It also saves a lot of time, as doing the analysis by hand, or inflicting the conditions to test the product in person, would be extremely time-consuming.

Once investment in Finite Element Analysis software has been made, it can be used for an endless number of products, constantly helping a business to keep its costs down and produce products of the highest quality.

### How GMT Uses Finite Element Analysis

We use a complex and reliable software that incorporates the accurate simulation of the behaviour of materials in our products. We use this software for non-linear analysis of the rubber behaviour to ensure an accurate modelling of the products we design and supply.

The software allows us to place product designs through a variety of different load cases and frequencies to ensure customer specifications can be met whilst ensuring product durability and life are maintained.

Finite Element Analysis plays a large and important role in our design and application process. We have thousands of existing products for customers to choose from, but through the use of Finite Element Analysis, we are able to offer optimised and bespoke solutions to our customers. Designed to meet customer requirements, FEA reduces the time required for us to produce these products.

• # 5 Signs You Need to Replace Engine Mounts

The primary purpose of an engine mount is to secure an engine into machinery, and to then absorb any shocks and vibrations when the machinery is operating. The anti-vibration properties of engine mounts are essential for preventing damage to the engine and for improving operator comfort (where applicable). However, no matter the quality of engine mounts, they begin to wear down after usage and require replacement. Not replacing an engine mount that is past its prime can inflict damage to the engine, cause discomfort for operators and potentially be a safety risk. Being aware of the following signs will help you to identify when your engine mounts need replacing.

1. #### Increased Vibrations

If you start your engine and notice that it is making more of a noise than usual, and can feel more vibrations than usual, this is a key sign that your engine mounts might need replacing. As a mounting is worn down, its anti-vibration properties weaken. An increase in vibrations leads to the engine making more of a sound than usual – something that can be extremely damaging to an engine if it continues for a long time.

1. #### Rocky Start

Upon starting a machine, you may notice an excessive lurch that doesn’t feel or sound healthy. This is a common indicator of a worn or damaged engine mount. This lurch then often steadies into a constant vibration, but you may then also experience a lurch when turning the ignition off.

1. #### A Bumpier Ride

Often, an engine mount that needs replacing can cause a jolt when changing gears on an attached transmission. This jolt or thump can also be noticeable when travelling at faster speeds due to the engine working harder. If your machine doesn’t feel as smooth as usual, this can often be down to a damaged engine mount.

1. #### Impact Noises

A worn engine mount can often lead to ‘clunks’ and ‘bangs’ within its surroundings/engine bay. This is as a result of the engine moving around more than normal and making contact with other components, which in turn can cause impact sounds that become quite noticeable.

1. #### Visual Wear

With use, the metal part of an engine mount does change in appearance. However, if you can see any significant corrosion, cracks or warps to the part, it is likely that excessive wear will be occurring to the rest of the mount. If you notice any cracks or flaking to the rubber aspect of an engine mount, this can potentially limit its performance depending on the severity of the cracks and the route cause. The efficiency and effectiveness of engine mounts relies on their form and shape, and so any changes to this can be damaging to the engine. If you do notice any of these signals, you should look into replacing engine mounts as quickly as possible.

If you experience any of these signs, it’s best to get the engine checked out and consider replacing the engine mounts. At GMT Rubber, we are market leaders in engine mount technology. Our experience allows us to identify the right engine mounts for your needs. Contact us today if you would like any more information or assistance.

• # Levelling Feet: A Comprehensive Guide

Levelling feet can stabilise a wide range of machinery, with the height adjustment feature of allowing machinery to be levelled when installed on uneven ground.

There are a variety of combinations and sizes available, meaning that there is a type to suit all applications. At GMT, spindles can be combined with various types of threaded foot plate, enabling customers to specify feet to their exact requirements. The feet can also be specified to have anti-slip rubber pads. Additionally, feet with high load bearing capacity and self-aligning capabilities are available.

### Materials

There are a variety of materials available for foot plates and spindle materials of levelling feet. These include polyamide, plated steel, and stainless steel. It is also possible to have levelling feet that are approved to medical, food, and hygiene industry standards.

The rubber pad material of these parts is oil and water-resistant, ensuring the longevity of products in cases of contamination of the foot plates. Additionally, the rubber can be UV resistant, non-marking, and anti-bacterial upon request. These unique benefits demonstrate the importance of rubber in such products.

### Foot Plate Features

All foot plates need to be able to withstand the correct load. Our standard foot plates have been designed for loads up to 500, 900, 1000, and 3000 daN depending on the foot plate selected.

Stainless steel foot plates guarantee optimum hygiene by way of a sealed couple foot. It is this feature that makes these types of levelling feet very well suited to environments containing food or special chemicals.

You have the ability to choose self-aligning levelling feet if appropriate. The heavy duty self-aligning foot plates are able to withstand loads of up to 4500 daN.

### Spindles

All of our spindles are either made from zinc coated steel or stainless steel. Each spindle can be matched with a variety of foot plates.

### Levelling Feet at GMT

It is extremely important to have the right materials and sizes of levelling feet, depending on their intended use. At GMT, having the range of sizes and materials that we have available, our levelling feet are extremely flexible to be suitable for different applications. Our levelling feet have a high-load capacity and are therefore suitable for a variety of applications.

### Installation of our Levelling Feet

Assembling levelling feet is a quick and easy process depending on the combination of spindle, footplate and anti-slip pad required.  For standard foot plates, the ball at the base of the stud is pressed or gently knocked into place in the opposing female spherical void in the footplate, the nuts can then be threaded onto the spindle and the anti-slip rubber pressed into place on the base.  The self-aligning feet are assembled through using the assembly set,  the spindle is inserted into the base and secured into place using the fastening set threaded fastener through the base of the footplate into the spindle.

• # What is 3D Modelling?

### How We Use 3D Modelling

Special software allows us to plan out and accurately represent the object we have in mind. Connecting geometric shapes, curved surfaces, and lines, the 3D model gives a mathematical description of the surface of the object. Here at GMT Rubber, if standard products are not suitable to a client, we are able to produce a new design using 3D modelling. This is used in conjunction with Finite Element Analysis (FEA). With knowledge of the client’s needs, we build a product to meet the specification whilst ensuring that the finished design is also capable of meeting service life/durability requirements.

The method of 3D modelling is used in conjunction with Finite Element Analysis (FEA) to further validate and finalise the development process. FEA is a computerised process that helps to predict how a product will react to forces when the product is actually used. This method involves breaking an object down into many finite elements. Mathematical equations are then able to assess the behaviour of each element if the product were to be made. In terms of how this is relevant to our products, we use FEA to predict and minimise areas of stress concentration. This allows us to manufacture the highest quality products that will work at maximum efficiency.

After the 3D modelling and FEA process, the 3D CAD model produced is then used to develop a mould to bring the designed product to life. GMT’s experienced tooling design engineers have to consider many factors in this process. This includes the fact that the mould has to be larger than the finished part to allow the rubber to contract as it cools after vulcanisation.

### Benefits of 3D Modelling

There are numerous reasons as to why 3D modelling is used in the creation of bespoke parts. Importantly, a 3D Model really brings an object to life, improving the visualisation of a new object. The software also saves a lot of time in terms of the development process. Drawings by hand would take time and are susceptible to human error. Furthermore, more designs would need to be produced to represent the full effect and detail that can be seen using a 3D model.

The whole process involved in creating a new product requires expertise and knowledge. With the help of 3D Modelling and FEA, the process is efficient and accurate. GMT produce a wide range of high-quality anti-vibration products, suitable to a variety of industries. If you would like any more information, do not hesitate to contact us.

• # Anti Vibration Mounts and Their Uses

Pieces of equipment and machinery subjected to noise, shocks and vibrations can be extremely damaged, affecting their lifespan, efficiency and safety. This can often lead to more frequent repairs and replacements, increasing costs for the company or individual. Anti Vibration Mountings tackle this by providing excellent shock absorption and vibration dampening properties. This ability makes them widely used and they can be found in industries ranging from the defence sector to renewable energy and power generation. As regulations become stricter, the demand for high quality, durable and effective anti vibration mounts is continuing to rise.

## Types of Anti-Vibration Mounts and their Use in Industry

By utilising the correct type of mount, you can increase the lifespan of machinery whilst reducing the adverse effects of vibration, noise and shock. GMT design, manufacture and supply a wide variety of specialised mounts, offering both stock and custom solutions for a multitude of industrial applications:

### Vibration Isolators

Our selection of Isolators fulfil two main uses- they can either reduce any noise transmitted outwards from the machine (active) or reduce the amount of vibrations that are travelling to the machine from an external source such as its foundations (passive).

Vibration Isolators can be found in many areas, such as in machinery for the food and pharmaceutical industries. Specific examples of use include heating and ventilation equipment, fans and power generators.

### Rubber Mounts

Unlike Vibration Isolators, Rubber Mountings can provide vibration and shock protection in three separate directions. They also provide high levels of resistance to grease and oil making them a popular choice in both the automotive and marine industry. Rubber mounts can often be found in both engines and generators.

### Wire Rope Mounts

Corrosion-resistant and completely manufactured from stainless steel, our specialist selection of Wire Rope Mounts are designed to withstand the toughest environments. They isolate shock and vibrations from all directions and offer a maintenance free solution to the most demanding tasks.

This resilience makes our range of wire rope mounts ideal for military use, certified to standards MIL-STD-167 for vibration, MIL-STD-810 for environmental conditions and MIL-S-901 for shock. They can be found in rough terrain vehicles, aircraft and vehicle carriers.

### Conical Mounts

Conical mounts are also referred to as rubber cone mounts. With the correct washers, these mounts are suited to both compression and shear loadings. Featuring a failsafe capacity and a high load capacity, they are designed to suit mobile applications for the automotive, commercial vehicle and marine industries.

### Machine Feet

Machine feet work to reduce vibrations whilst dampening shock loads. With the option of rebound control and a variety of rubber hardness options to suit each application, it isn’t difficult to see why machine feet are used so extensively in industries such as Renewable Energy, Power Generation and Agriculture and Forestry. Common applications include marine mountings, engine mountings and generator mountings.

#### Enquire Today

GMT Rubber have a dedicated team of professionals who would be more than happy to answer any of your questions. For more information regarding any of our specialist Anti Vibration Mountings or to enquire about our bespoke service, please don’t hesitate to get in touch today.

• # The Advantages of Using Rubber Bushes

There are various Anti Vibration products available that can improve the function and lifespan of various systems and machinery. Not only do vibrations cause damage to products, but they can also produce noises which are both uncomfortable and harmful to operators. Because of this, it is important to use the right Anti Vibration products in the right places.

For example, in suspension systems, reducing vibrations is essential to prevent noise and vibrations travelling through both on and off-road vehicles. Rubber bushes are a great and effective product for achieving this.

# What is a Rubber Bush?

A Rubber Bush, sometimes referred to as a rubber bushing, is a type of vibration isolator that provides a flexible interface between two rigid parts. The rubber bush acts as a buffer, absorbing and damping energy produced by the interaction of these two parts. It separates the parts while allowing a limited amount of movement thereby minimising vibration and noise.

Rubber bushes usually come in the form of a cylinder, encased in an inner and outer metal. In between these layers is vulcanised and bonded rubber. The metals can be produced in a wide range of materials including mild steel, stainless steel, and aluminium. Bushes are stress relieved after vulcanisation and can be pre-stressed for improved durability. Their dimensions, profile and rubber are designed to suit a specific application using various techniques such as finite element analysis to ensure optimised performance and durability.

GMT’s rubber bushes are suitable as mechanical joints on road and rail vehicle suspensions, pivot arms, engine mountings, gearbox mountings, and as captive cab mountings.

Rubber suspension bushes play a critical role in vehicle safety and comfort when driving, used for positioning and aligning suspension and steering components. These include shock absorbers, sway bars, control links and torsion bars. It is important for bushes to be in good condition, to avoid rapid tyre wear and steering or breaking problems.

Using rubber bushes can minimise the noise caused by vibration, remove the need for lubrication. Because of this, they are often preferred over solid connections. Rubber bushes also make great shock absorbers, vibration isolators and abrasion resistors.

Repeated vibrations can be the source of damage to suspension systems, contributing to the weakening of this type of system and surrounding structure. Rubber bushes work to prevent this from happening, minimising the vibrations and their resultant damage.

Rubber bushes can provide a long maintenance free service life. They can also be optimised and tuned to provide specific stiffness characteristics in different directions. They can also provide articulation by way of torsional, conical movements where other anti-vibration products may not be able to do so. Rubber bushes are usually pressed into a housing thereby eliminating the need for the use of separate fixing mechanisms. Where required however, central inner metals can be incorporated into the design to facilitate fixing the inner metal to surrounding structures using bolts.

## Where Rubber Bushes Came From

The use of rubber bushings in vehicles has been credited to Walter Chrysler, an American automotive industry executive. Walter encouraged the adoption of rubber vibration isolating mounts to cut down the vibration and noise of vehicles. From then on, rubber bushes were adopted for use in many parts that generate vibration and noise, and are now a conventional method across the automotive and commercial vehicle industries.

If you require a rubber bush, or would like some more help or information on which to buy, please feel free to contact us. We have a wide range of rubber bushes and other anti-vibration mounts available. If you require rubber bushes for a specific application, we are able to offer a custom service.

• # Using Rubber for Effective Anti Vibration

A wide variety of industries, including aerospace, defence and material handling require solutions to limit noise, vibration isolation and shock. GMT specialises in providing anti vibration products to cater for each industry, offering a range of specialist and bespoke solutions to protect your equipment, vehicles and machinery.

## What material absorbs vibration the best?

Rubber is widely regarded as the best material for vibration isolation, however the type of rubber which should be used will vary depending on the properties of the job. There is a common misconception that rubber only refers to one type of material. In reality, there are many different types and compounds which have been created and adapted to suit specific conditions and applications.

The different rubber compounds fall into two main categories, natural and synthetic rubber. Natural rubber is made from latex, a substance originating from plants. Synthetic rubber is produced in chemical plants and laboratories. The difference in how these are produced means that they have fairly different compound structures, which will affect their individual properties.

Both types of rubber have their benefits, and GMT will use both natural and synthetic rubber, depending on the use and requirements of each product. Our natural rubber features excellent resilience, as well as fantastic surface friction and abrasion properties. We source our rubber latex from rubber tree plantations across the globe, helping us to find the best quality product for consistent results.

When we receive the latex, our team will compound it, using our high tech systems to ensure consistent results. We can choose your specific rubber type from thousands of combinations, using our knowledge and expertise to achieve the perfect anti vibration material for your particular requirement. The rubber is mixed by the GMT team, enabling us to control quality and timescale. This helps us to deliver your durable anti vibration solution on time without any issues.

### Why is it important to reduce vibrations in certain industries?

Vibrations and shock can cause damage and wear to equipment and machinery across a range of industries. This often leads to a shorter lifespan, a poorer performance and unnecessary noise. In some cases, vibrations and shock can even cause machinery to break, something which could be avoided with the correct anti vibration product.

Replacing equipment and machinery often comes with a considerable cost, eating into profit margins and affecting production time and efficiency. Investing in anti vibration solutions will help to keep your machinery and equipment running safely and efficiently for as long as possible, protecting your equipment and helping you to experience the best performance for a considerable length of time.

An example of this is our selection of Cone Mounts, which offer a fantastic method of vibration reduction whilst withstanding shock loads. They also have the added benefit of failsafe overload and rebound control. GMT have a variety of Cone Mounts in stock and also offer custom solutions to suit individual requirements.

### Contact GMT Today

GMT have many years of experience in producing innovative new solutions, and we love a challenge. If you would like to learn more about our anti vibration products, please don’t hesitate to get in touch with a member of our knowledgeable team today.

• # Why Use Variable Stiffness Hydraulic Rubber Bushes?

GMT’s range of technically advanced variable stiffness hydraulic axle guide bushes have already been successfully implemented for many years on major train manufacturers bogies to provide adaptive levels of stiffness for bogie axles running on tracks. Train operators are also taking advantage of the reduced wear and tear of wheels and tracks to reduce noise and energy consumption and associated track running costs.

The same technology is also being widely adopted in automotive and commercial vehicle suspension and engine mount applications to provide adaptive responses to changing environments, speeds and conditions as customers demand ever more comfort and performance.