LLG Rubber Bearings

Looking for a multi-layer rubber sheet and thin steel plate rubber bearing with quality assurance? LLG Rubber Bearing is for you.

LLG Rubber Bearing has 20 years of involvement with product design and production, selling bridge bearings, rubber sealing belts, building bearings, bridge expansion, and contraction devices, geomembrane materials, inserted parts, metal bellows, polyethylene closed.

In Addition, LLG Rubber Bearing has numerous product certifications like ISO9001, CE, and BV. We also have long-term cooperated forwarders that make shipping costs low and fast. LLG Rubber Bearing has also strict quality control.

Our LLG Rubber Bearing is a combined transfer of service and seismic loads leading to minimal space requirement to the devices. LLG Rubber Bearing is an effective solution for retrofitting or upgrading existing structures.

Furthermore, our LLG Rubber Bearing has precision rating of ABEC-1,ABEC-3,ABEC-5, seals type of ZZ 2RS OPEN, and Single/Double number rows. LLG Rubber Bearing has also vibrating rating of V1 V2 V3 V4, clearance rating of C2 C0 C3 C4 C5, and supply ability of 20000 Meter/ Month.

Send you inquires and grab yours now! Call us, and our approachable staff will give you exceptional accommodation.

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Rubber Bearing- The Ultimate FAQ Guide

Every individual keep a wanderlust which takes him to his fantasy world. People travel through bridges, reach meadows and live their lives to the fullest. 

When traveling through the bridges, stiffness and tensile strength of bridge is important to carry heavy loads. Even in heavy rains, stable material for constructing bridges is important to avoid any accident. 

Bridges are made of rubber bearing to ensure efficient stiffness and working. Financiers’ are in search of bearings that provide a good support and work efficiently. 

In this write-up, you will be informed about benefits and working of rubber bearing.

• What Is a Rubber Bearing?

A rubber bearing consist of an equipment which allows a parallel motion between the parts such as linear movement as well as rotational movement. 

Rubber bearing diminishes the friction produced as a result of contact between different rotating parts. Rubber bearings are classified on the reason of their operation as well as relative motion. 

Rubber bearing works best in the conditions when the lubricant has a coarse material. Rubber bearings are tough just like a material used to make automobile tire.

Rubber bearings operate on the principle of base isolation and reduce the vibrations produced in the base whenever an earthquake occurs to avoid any damage.

The damping effect of a bearing made of high quality rubber is approximately 5% or less than 5%. Rubber bearings possess incorporated rubber bands with the steel plates. Such structure is used to ensure weather protection. 

Rubber bearings provide a good support in earthquakes, hurricanes, heavy traffic and freight trains. 

Rubber bearing is easy to install and handle and have and ability to alter or change some energy into heat when it is deflected. This method is known as hysteresis. 

Rubber bearing are free from corrosion. 

Rubber Bearing

• What Is Rubber Bearing Used for?

Everything in the world faces stress. Apart from natural stress, man-made structures experience stress either structure is concrete or have super strength. They have two phases; stay or fail. 

Rubber bearing is a device which can bear high shocks and have the ability to resist cold, heat and seismic waves.  

Rubber used in the rubber bearing are made of polymers which have capacity to stretch as well as recovering strength and they keep the bridges stand. 

Rubber bearing is used to eliminate abrasives found in the lubricant. Rubber bearing decreases the friction and wear between the moving parts. 

Rubber bearings which are used as isolation in seismic structure and experience huge shear deformation when earthquakes happen.

Rubber bearings can be compressed by load and traffic on it. 

Applications 

• Car tiers
• Pacifiers 
• Aircraft 
• Bridges 

• What Are the Types of Rubber Bearing?

Rubber bearing is an important component in the construction and balancing of bridges as they assist in linear and rotational movements. Many different types of rubber bearings are as follow:

• Laminated and plain elastomeric bearings
• Rubber bearings (High Damping)
• Rubber bearings (Low Damping)
• Rubber bearings (Lead)

Laminated and Plain Elastomeric Rubber Bearings

These types of bearings are used in construction machines and possess natural or neoprene rubber. Laminated and plain rubber bearings provides with the isolation method which is simple. 

Laminated and plain rubber bearings have the capability to bear higher frequency shocks in the base area. 

Rubber Bearings (High Damping)

The abbreviated used for such bearings is HDRB. Such bearings are suitable for seismic isolation. 

High damping rubber bearings can bear vertical gravity forces and permits greater horizontal displacement. They are vertically stiff in nature. 

Whenever natural disaster like earthquake occurs, such bearing have the ability to move to and fro under base isolation and also helps the super structure to last static. 

HDRBs are the bearings which are malleable and absorb vibrations to avoid breakage or tear of the roads or bridges. 

Rubber Bearings (Low Damping)

The best bearing used for the buildings and bridges is the low damping rubber bearing with dampers. Such bearings are available with dynamic characteristics. It is also abbreviated as LDRB.

Rubber Bearings (Lead)

This kind of rubber bearing is a huge rubber bearing which is formed of layers of rubber that are sandwiched along with the steel and a plug which is placed in the middle. 

Mentioned structure of such rubber bearings made of lead is such that the upper and the lower ends are fixed with the steel plates which help to attach the buildings. 

Lead rubber bearings are malleable and ductile from horizontal side and rigid in structure from vertical position. 

Steel plates in these special rubber bearings provide support and keep their structure stable as well as disappears the vibrations of seismic waves. 

• What does a Rubber Bearing do?

Rubber bearings perform well on the principle of base isolation and restrict the energy or vibrations moving from the base area to the structure such as bridge or a building in case of earthquakes or hurricanes. 

Rubber bearings made of lead have a laminated rubber and steel plates to install easily with the foundation. 

Rubber bearings can withstand axial pressure because of greater vertical rigidity and strength. Whenever a greater vertical load is applied, plastic shear deformation occurs with the help of rubber and incorporated steel plates. 

In such case, rubber bearings absorb the vibrations to prevent from severe damage. 

Lead rubber bearings operate well in seismic waves. Such bearings reduce the high speed and alter the large forces applied on the bridge

Rubber bearings made of lead have the ability to control the displacement and stops the bridges from falling down. 

• Which Type of Elastomeric Bearing Is?

Elastomeric or a laminated plain bearing is referred as a bridge bearing. The elastomeric bearings consist of steel plates combined with the rubber. 

Such bearings are used to withstand pressure as well as change in structure equally. Elastomeric bearings restrict the vertical loads. Steels plated being fixed in the elastomer does not face any damage. 

Elastomeric rubber bearings allow horizontal displacement due to flexibility of the rubber. 

Elastomeric bearings are the bearings which compress upon vertical pressure applied and can withstand horizontal displacement. 

Elastomeric bearings are designed in a specific style that they are flexible or malleable in shear and rigid in volume changing. 

Elastomeric bearings become stiff when low temperature is provided. Elastomeric bearings are used as a motion control device during wind or earthquake loads. 

Elastomeric bearings consist of neoprene or natural rubber as their building blocks. 

Elastomeric Rubber Bearing

• Why is Rubber Bearing used in Bridges?

A bridge consists of bridge deck which is supported by piers. Bride bearings have the power to compensate the damage caused by heavy traffic movement over the bridge and prevent from bending movements and restrict the safety of structure.

Rubber is made of polymers and it is its’ specification that the can stretch and recover in case of stress to keep the bridges in place. 

Rubber bearings consist of a rubber bearing pads and they are fixed between the surfaces or pillars of the bridge to avoid falling of bridges in case of any failure. 

The rubber bearings made of neoprene are mostly used in bridges and operate well in a dry hot and cold condition to prevent from falling or damage caused by stress. 

• What do you know about the failures of Rubber Bearing?

Rubber bearings are the bearings which limit the friction produced as a result of contact between the rotating parts. Rubber bearings consist of bearing pads that are placed in between the pillars or surfaces of bridges.

Failures which rubber bearings in the bridges encounter are as follow:

• Delamination
• Slippage 
• Crushing 

Delamination Failure

This is a form of failure where a material undergo breakdown into many layers. Also top layers of the concrete separate from the concrete underlying.

Delamination Failure

Slippage Failure

Slippage failure is caused by shear forces which occurs when a vehicle move and stop. Gravity, centrifugal forces and deceleration are the factors affecting it. 

When a hydraulic pressure is exerted on to the interface of layers, slippage occur causing damage of bridge. So, tack coats are utilized to remove this failure and to enhance bonding linkage.

Crushing Failure

Crushing failure or a column failure is a failure in rubber bearing which occurs when short columns are exposed to great load that reaches beyond the limit.

• What Are the Multi-axial Behaviors of Laminated Rubber Bearings?

These multi-axial behaviors are the cyclic behaviors of rubber bearings which are in laminated form. There are three types of laminated rubber bearings and their behaviors are defined as:

• Features of the restoring forces of laminated rubber bearings are determined in small amplitude. 

The result evaluated depicts that gelding ratio is reduced when the amplitude increases while rigidity of the HDRB is increased with the increase in amplitude. The restoring force determined is totally based on the vertical load. 

• A consistent vertical pressure is applied on the bidirectional paths of the rubber bearings which are laminated and this behavior is noticed under tri-axial load method.

After the evaluation, it is noticed that parallel restoring forces have a coupling effect. The rigidity as well as the damping value of natural as well as high damping rubber bearings is increased as a cause of coupling effect while such properties for laminated lead rubber bearing experience a reduction in them. 

• Thirdly, a tri-axial hybrid seismic determining experience is evaluated

• What do you know about High damping Rubber Bearings?

High damping rubber bearings are the bearings which can bear high frequency earthquakes without facing and type of damage. High damping rubber bearings are made of steel and rubber layers. 

Steel plated used in such bearings have ability to elevate the vertical rigidity. Such HDRBs’ are used to bear vertical forces when a greater shear displacement occurs. 

These type of rubber bearings are designed in such a style that when shear deformation occurs, there is no overlapping between the end plates. 

High damping rubber bearings limit the requirement of viscous or elastomeric-plastic steel dampers in the base isolation area. 

These rubber bearings protect the buildings or bridges from damage. These bearings have greater elasticity and high durability properties. 

High damping rubber bearings beside their stiff nature becomes flexible in horizontal way to limit the earthquake force and alter its’ own shape. 

High damping rubber if formed by adding additives such as graphite into natural rubber to enhance the visco-elasticity behavior

High Damping Rubber Bearing

• What Are the Effects of Heating on the Behavior of Rubber Bearings?

Strength of the rubber bearings decreases with the increase in number of cycles when a constant heat is given to the lead core of the bearings. 

The decrease in the efficient working of rubber bearing is due to geometric characteristics as well as relative speed of movement. 

At low temperature, rubber used in rubber bearings experience crystallization rigidity which affects the working properties of rubber bearings. 

When the temperature is increased, the aging process of rubber bearing increases which result in greater oxidation reaction. 

Increase the heat from 60⁰C to 120⁰C, this will cause shear failure of rubber bearing and hot air causes more damage to natural rubber bearing than mineral water. 

• What do you know about Water-Lubricated Rubber Bearings?

A water-lubricated rubber bearing is a type of bearing which is used in stern tube system in the marine propulsion shafting. Water-lubricated rubber bearing control the stern shaft and is an important part of inside as well as outside power exchange. 

Water-lubricated rubber bearings are pollution-free, possess high energy and these bearings are friendly with the surrounding environment. 

Water-lubricated rubber bearings have a layer of water film and it is 1/8 in thickness. Such bearings operate with low speed but can bear heavy pressure or load. 

One disadvantage is that water-lubricated bearings produce a lot of vibrations or noise which needs to be reduced. 

Water-lubricated rubber bearings may wear down when used for a long period. They are not durable for a longer period. 

Water-Lubricated Rubber Bearing

Structure

Full mode water-lubricated rubber bearings are found widely and are common. Rubber used in such bearings is attached to the inner side of a metal shell and for water passage many holes are made in the rubber. 

Another form used in water-lubricated rubber bearing is segmental type bearing. It used commonly used when the shaft has huge diameter. 

This structure is applicable because it needs a little maintenance and do not cost expensive. 

• What Are the Properties of Rubber Bearings made of Lead?

A lead rubber bearing used in making of superstructures as well as bridges has following properties:

• Aging resistance
• Recovering capacity
• Good and easy maintenance 
• Strong seismic ability 
• High purity lead
• Resistant to corrosion 

 Lead Rubber Bearing

• What Is the Vibration Measurement of a Rubber Bearing?

Vibrations or shocks reduces the bearing life and elevates the fatigue rate. To measure the vibration of rubber bearings, following points must be considered. 

The vibration movements in an object are marked as displacement. The movement from the initial points to the higher and lower points and then back to such position is called as a cycle. The vibrating cycle lasts until the rubber bearings keep on rotating. 

Measurement of a vibration of rubber bearing is given by vibration velocity. Vibration velocity is given as higher the vibration, greater the noise. It is a simplification of frequency and displacement.

Dirt and dust also increases vibrations in rubber bearings. Poor fitting and dents are also essential in measuring the vibration of rubber bearings.

• What Is the Design Specification of Rubber Bearing?

Rubber bearings are regarded as the best vibration isolation bearings. Vibrations and high frequency shocks result in damage or wear of the buildings and reduce the bearing life. 

Thus rubber bearing performs best in such situations and reduces such risks of failure due to its’ longer life and stiffness properties. 

Rubber bearings consist of steel shims embedded with layers of rubber which can bear horizontal displacement without destruction of superstructure. 

A rubber bearing have the design characteristics such as:

• Shear modulus
• Thickness of rubber
• Thickness of steel plates which are made of carbon steel
• Inner rubber tensile strength is greater than 19.6 N/mm2
• Embedded shim plates are 48.4mm
• Rubber bearing has vertical stiffness of about 2019 KN/mm
• Rubber bearing has horizontal stiffness of about 1.46 KN/mm
• Gravity of rubber bearing is around 0.58 N/mm2

• What Are the Types Used in Making Rubber Bearings?

Rubber bearing is a device which offers rotational and linear motion and reduces the friction and wear between the rotating parts. The types used to prepare rubber bearings are as follow:

• Natural rubber 
• Neoprene rubber
• Butadiene rubber
• Butyl rubber 
• Lead rubber

• What Are the Characteristics of Rubber Bearings (High Damping)?

These high damping rubber bearings work best in seismic isolation. These rubber bearings are rigid and can withstand easily vertical pressure put on it. 

The characteristics of such bearings are as follow:

• High damping rubber bearings have low horizontal and high vertical stiffness and displacement
• High damping rubber bearings can withstand gravity pressure or forces for a longer period
• High damping rubber bearings support heavy horizontal displacement when earthquakes occur
• High damping rubber bearings have the ability to support vertical seismic loads
• Damping coefficient for high damping rubber bearing is around 15%
• High damping rubber bearings can realign the structure after exposure to earthquakes
• High damping rubber bearings have greater horizontal rigidity for wind restraints

• What Are the Properties of Rubber Bearings?

Apart from other bearings, rubber bearings possess some unique properties which make them used widely. These properties are:

• Tensile strength 

When a bearing made of rubber is used, a lot of force is needed to stretch it. When it is stretched beyond the limit, it breaks. This force applied to break it is called as tensile strength. 

Tensile Strength of Rubber Bearing

A bridge pad is placed underneath the piling and surface to protect it. When there is a motion of bridge, rubber bearing is moved to and fro. In this case, the bearing pad must stay static. The ultimate extention and shrinkage due to weather is known as tensile strength. 

• Compression 

Compression is a property of rubber to squeeze and gain back its original position. Rubber bearings are used in bridges because when a loaded vehicle run over the bridge, the rubber pads placed in the piling and surface compress a little bit, absorbs the force over it and then return to its original position. 

• Density 

Density is often confused with the term weight but it actually defines the quality of a rubber. 

• Temperature 

Rubber bearings depend upon the temperature of the environment and retain the superstructure of the bridge. 

• Resilience 

This is the property of a rubber bearing which measures how much thickness rubber has gained after restoring its natural position. Does it show any flexibility after stress? 

Resilience is defined as the rate of energy given out in deformation retrieval to the energy which results in deformation.

• Does the Rubber Bearing Helps in Reduction of Vibrations?

Yes, rubber bearings have the ability to reduce or absorb the vibration or high frequency shocks caused by natural disasters as well as overloaded traffic. 

Vibrations result in wear and damage of the tools, machines as well as superstructures and reduce the bearing life. 

Rubber bearings have dampers which reduce the vibrations and the vibration is turned into heat and dispersed to prevent from damage. 

• How to Determine the Size of an Elastomeric Rubber Bearing?

In case of elastomeric rubber bearings, horizontal motion of bridge is controlled by shear stress while vertical load is restrained by the compression. 

The area of an elastomeric rubber bearing is known by the suitable applied pressure on the bearing support.

Size of an elastomeric rubber bearing is determined by the distance between the superstructure and the border of the bearings due to presence of tensile stress or load which is caused by distance and results in delamination. 

• What Are the Merits and Demerits of Laminated Elastomeric Rubber Bearings?

The merits and demerits of laminated elastomeric rubber bearings are as follow:

Merits 

• Laminated elastomeric rubber bearings cost less than other bearings
• Laminated elastomeric rubber bearings require low maintenance when installation is done properly
• Such bearings are combination of stainless steel as well as PTFE to compensate greater movements

Demerits 

• Laminated elastomeric rubber bearings are not good for multi-rotation movements
• Laminated elastomeric rubber bearings can face slippage problem when they are not installed or fixed properly
• Laminated elastomeric rubber bearings shows greater deflection in a vertical way

For more information about the importance or working of rubber bearings, just contact at LLG Bearings. 

LLG Bearing provides best quality rubber bearings which fits the demand of their customers. 

LLG Bearing is never late to satisfy their customers.