LLG Roller Bearings

A roller bearing helps move significantly heavier and oversized objects. The primary function of the bearing is to decrease the friction that occurs when an object moves.

Roller bearing has line contact that allows it to resist more significant shocks. It will enable high rotational speeds and decreases heat, wear, noise, and energy depletion.  It utilizes cylinders for upholding the isolation between the moving parts of the bearing.

Roller bearing provides support to oscillating elements of machines like wheels and shafts. This type of bearing is cost-effective that gives good results without costing a lot of money and time.

Roller Bearings are commonly used in applications such as vehicles, skates, gearboxes, skateboards, mechanical fans, electrical Motors, paper manufacturing equipment, and rotatory mills; they are also used by mechanical hobbyists in industrial machinery, along with various other fields.

If you buy Roller Bearings from LLG, you’ll find they can use strong load capacity and support both high dynamic or static load.

LLG ensures first-class quality services to keep our innovation sustainable and exceed customer expectations, ensuring your satisfaction with their products, such as the Roller Bearings.  Send over any form of inquiries that you have. Our staff will help you throughout your ordering process.

If you have any inquiries or if you are interested in Roller Bearings, you can contact us.

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Roller Bearing- The Ultimate FAQs Guide

Are you in search of a bearing that carries a load while minimizing friction?

Looking for a bearing that can handle higher loads than conventional ball bearings?

Or a bearing that provides high performance while having a high axial and radial load?

If yes, then welcome to the LLG Bearing platform. LLG’s Roller bearing can help you out.

Following is the FAQ guide that will make everything clear.

Let’s get started!

1. What Is a Roller Bearing?

A roller bearing (also called rolling-element bearing) is a cylinder-shaped or sphere-shaped bearing that helps move significantly heavier and oversized objects. 

The primary function of the bearing is to decrease the friction that occurs when an object moves. You can use roller bearings in places where high accuracy is required.

Roller Bearing is corresponding to ball bearing. Roller bearings support loads with the help of cylindrical rollers rather than balls.

Roller bearing has a line contact that allows it to resist more significant shocks. It will enable high rotational speeds and decreases heat, wear, noise, and energy depletion.  

It utilizes cylinders for upholding the isolation between the moving parts of the bearing.

Roller bearing provides support to oscillating elements of machines like wheels and shafts. Roller bearing is a cost-effective solution that gives good results without costing a lot of money and time.

A Roller Bearing

2. What Are the Parts of Roller Bearing?

A roller bearing comprises two rings (one inner ring and the other outer ring) along with raceways, rolling elements, and a cage that helps in the separation of rolling elements and guide motion.

Inner& Outer Ring:  The rings are made from chrome alloy steel. This is high purity material and has a long service life and high load rates. The raceways have the necessary hardness and are ground.

Inner ring

Outer ring

Rolling Elements: Rolling elements are also made from chrome alloy steel. These elements include spheres, rollers, or balls. The rolling elements can roll on the raceways of outer and inner rings and are guided by a unique structure known as a cage.

Cage: The cage separates the rolling elements and helps them in motion. The cage is made from steel, plastic, and brass. The material used to make pressed cage include sheet metal, while soli metal cages are produced using machining techniques. 

Parts of Roller Bearing

3. What Are the Several Types of Rollers Bearing?

Roller bearings are available in variable types. Here, you will come to know the popular types of roller bearings.

Tapper roller bearings:  These types of roller bearings help in supporting thrust and radial loads. You can get these bearings in metric sizes and inches. 

Tapper roller bearings cannot handle bi-directional axial loads, so a laterally reversed bearing is also essential for counter-stay.

A Tapper roller bearing

Cylindrical roller bearings: in comparison with ball bearings, the cylindrical roller bearings can bear higher loads. They are used in high-speed applications because they can tolerate higher radial loads.

A Cylindrical roller bearing

Spherical roller bearings: These bearings can tolerate heavy loads even when allocating with shaft deflection and misconfiguration. 

These are available with internal clearances and can handle axial loads and shock loads in every direction. The bore dimensions of these bearings have a range from 20mm to 900 mm.

A Spherical roller bearing

Needle roller bearings: This bearing is available with or without an inner ring. These bearings are thinner as compared to other roller bearings. These bearings are ideal for handling heavy radial loads.  These types of approaches are available in metric seals and inches.

They are used where space is limited – thanks to there compact designs.

A Needle roller bearing

4. What Is an Axial Needle Roller Bearing?

An axial needle roller bearing is beneficial where:

• No radial loads are present
• High axial forces are unidirectional
• Higher speeds occur
• The available axial space is minimal
• The bearing parts can be mounted separately
• The bearing arrangement has high axial rigidity

5. Can a Roller Bearing Be Mounted without a Sleeve?

A roller bearing can be mounted with or without a sleeve. A guiding sleeve is necessary when mounting needle roller bearing and cylindrical roller bearings with an inner ring. 

The raceway diameter of the inner ring and the sleeve’s outer diameter should be identical.

Spherical roller bearings have cylindrical bores for mounting in the presence or absence of a sleeve adapter.

Here is the link that shows how to fit bearing with the sleeve on the shaft: 

6. What Is the Standard Size of a Roller Bearing?

Different types of roller bearings have different sizes.

• The cylindrical roller bearing’s diameter ranges from 20-200mm. 
• The diameter of tapered roller bearing ranges from 15-200mm.
• The diameter of spherical roller bearing has a range of 25-300mm.
• Spherical thrust roller bearing has a diameter range of 60-30mm.

Standard bearing sizes of roller bearings

7. What Are the Applications of Roller Bearing?

1. a) Applications of spherical roller bearings: Mining equipment, construction equipment, gearboxes, material handling, blowers, wind turbines, casting machines, marine propulsion, off-road vehicles, pumps, offshore drilling, paper processing equipment, mechanical fans, and pulp processing equipment.
2. b) Applications of cylindrical roller bearings: Power generation, crushers, fans and blowers, machine tools, pumps, mining, rolling mills, traction motors, petroleum production, traction pumps, power transmission, plastic machinery, fans and blowers, paper processing machinery, cement processing, rolling mills metal recycling, rubber mixing equipment, and rotatory dryers.
3. c) Applications of Needle roller bearings: gearboxes, air compressors, pumps, rocker arm pivots, stroke engines, rocker arm pivots, and planetary gear sets.
4. d) Applications of tapered roller bearing: These bearings have a wide variety of applications in agriculture, mining equipment, wind turbines, axle systems, gearbox, engine motors, sports robot combat, railroad axle-box, reducers, differential, and construction equipment.

Here is the link to the application of roller bearings:

8. How to Calculate the Rating Life of a Roller Bearing?

Rating life is calculated for ninety percent reliability. It is also known as bearing life. It is defined as “The time that the similar roller bearings will complete or surpass before the development of fatigue spall.”

The formula of bearing L10 rating life is given below:

In the above formula 

C donates dynamic capacity measured in Lbs.

P donates equivalent bearing load measured in lbs. or N

N is equal to rotating speed

e = 10/3 for the roller bearing.

We can calculate the rating life of every type of roller bearing by putting the appropriate values in the above formula.

9. What Are the Metallic Materials Used in Roller Bearing?

SAE 52100 (chrome steel) is used in the construction of roller bearing. This steel has an excellent capacity to resist wear. The bearings made of this material can perform a function up to the temperature of 120 degrees centigrade. The disadvantage of chrome steel bearings is that they are predisposed to corrosion because of having low chromium content.

AISI 440C (stainless steel) is superior to SAE 52100 because it can resist corrosion. They have higher chromium content than SAE 52100 chrome steel, which makes them loftier than chrome steel. 

They have low load-bearing capacity but have a higher production cost. As, it is a high-carbon stainless steel, it is suitable to make roller bearings.

The drawback of this high carbon stainless steel is that the fatigue life is shorter than SAE 52100 steel.

Following are the metallic materials that are also used in roller bearings:

• Bronze
• Silver
• Cast iron
• Babbitt metal
• Copper-lead alloys
• Aluminum alloys 

Materials used in roller bearings

10. What Is the Composition of Metallic Materials Used in Roller Bearing?

The SAE 52100 and AISI 440C that are used in roller bearings are composed of many elements. 

• The element carbon presents in SAE 52100 (chrome steel) ranges from 0.95-1.1% and in AISI 440C (stainless steel) it ranges from 0.95-1.2%.
• The amount of chromium in SAE 52100 is from 1.3-1.6%. In high carbon stainless steel, it ranges from 16-18%.
• Silicon has a range of 0.15-0.35% in SAE 52100 and 1% max in AISI 440C.
• Manganese present in SAE 52100 is 0.5% max and 1% max in AISI 440C.
• Molybdenum is 0.08% max in SAE 52100 and 075% max in AISI 440C.
• The element phosphorus is 0.012% max in chrome steel SAE 52100 and 0.04% max in stainless steel AISI 440C.
• Nickel is 0.025% max in SAE 52100 and 0.25 % max in AISI 440C. Its concentration is the same in both SAE 52100 and AISI 440C.
• Sulphur is 0.25% max in SAE 52100 and 0.30% max in AISI 440C.

11. What Is the Non-Metallic Materials Used in Roller Bearing?

Nylon is one of the non-metallic materials used in roller bearing. It is excellent fatigue-resistant material. It also has an outstanding wear characteristics and toughness.

You can use nylon bearings in many household applications. Nylon is well suited for bearings and is filled with MoS2.

Teflon is commonly known as polytetrafluoroethylene. It is a very suitable non-metallic metal for roller bearing cages because of its following properties:

• Self-lubricating property
• Low friction coefficient
• High chemical inertness

Phenolic materials are resistant to alkali solutions, acidic solutions, and water.  They are not appropriate for high-load speed appliances because their thermal conductivity is low, and they expand. They are used in electrical switch gears and shift propeller bearings. They are lightweight and have high strength. Plastics are often used in their place because they are costly to produce.

Nitrile rubber is not expensive to produce. It has good mechanical properties and has chemicals resistance. It can work efficiently in a wide temperature range. It is the most reliable bearing seal material.

Non-metallic material used in bearings

12. What Are the Ways to Grease the Roller Bearing?

Grease is one of the commonly used lubricants which are used for the lubrication of roller bearing. The greasing of roller bearing carries the heat away, protects the surface of roller bearing from corrosion, reduces friction, increases the bearing life, and provides safety against contamination. For the lubrication of bearing, be sure to use grease that is free of contaminants.

Following are the ways to grease the roller bearing by hand.

1. Put on latex gloves by cleaning your hands.
2. Place appropriate grease into the palm of your hands.
3. Push the end (more prominent end) of the roller bearing cone assembly into the grease present on the opposite palm.
4. Rotate the cone assembly continuously until the grease is evenly distributed around the whole end of the cone.
5. At last, smear the remaining grease on the cone assembly of a roller bearing on the outer side.

Greasing the roller bearing

13. How to Replace Roller Bearing?

Roller bearings sometimes cause complications for a many applications. So, you can replace them with the simplicity of plain bearings. 

Following steps should be taken to order the correct replacement bearings.

1. First of all, detect the type of bearing you need to substitute.
2. Detect the bearing identification numbers that are typically available on the outer and inner ring face.
3. If you do not locate the identification number, you have to measure various dimensions, like:

• the outer side of the outer ring, 
• inside diameter of the inside ring, 
• inner and outer width, 
• outside diameter of roller bearing, and 
• the shape of the bore.

14. How to Clean Roller Bearings?

Cleaning the roller bearing is necessary for its proper working. Some people either never clean their bearings or clean improperly.

Following are the standard ways of cleaning.

1. First of all, you have to remove the bearing.
2. After this, take your bearings apart.
3. Put the bearing in a container containing isopropyl alcohol and cover the container with a lid. This will clean your bearing.
4. Re-lubricate your bearings.
5. At last, place your wheels back together.

Here is the link to the video that displays the ways to put back the wheels together.

15. How Do Different Types of Rollers Bearing Work?

Tapered roller bearing rolls freely across the hub and shaft’s mating surfaces that prevent metal grinding, wear, and heat. These types of bearings are held together by an inner race and an inner radial surface.

The inner radial surface of the inner race is flat to slide over a shaft, and the outer surface of the inner race is tapered for the bearings to roll against. 

The outer race is precisely opposite to the inner race. In the outer race, the inner surface is tapered, and the outer surface is flat. The tapered angle of the bearings handles thrust (axial) and radial loads.

Spherical roller bearings work by permitting angular misalignment and rotation with low friction. These bearings upkeep a rotating shaft in the bore of the inner ring that may be misaligned regarding the outer ring. 

The misalignment is probable due to the spherical form of the outer rings and spherical rollers.

Cylindrical roller bearings are capable of carrying load in one direction. You can use the double-row cylindrical roller bearings for precision machine tools because they have high radial rigidity.

Needle roller bearings work by supporting rotational speeds and radial loads. These roller bearings decrease the friction of a rotating surface of needle rollers. These bearings handle high loads.

Here is the link that shows the working of roller bearings.

16. What Are the Principles of Roller Bearing Selection?

When roller bearing selection is made, you should know the following points:

1. You should know the general information on roller bearings.
2. You should have enough information for the detection and identification of bearing tolerances.
3. You should know how to deal with LLG bearings.
4. Bearing selection process should be clearly defined to analyze and determine the bearing solution.
5. If you need any assistance regarding the selection of bearing, you may contact the LLG application engineering service.

Roller bearing selection

17. What Are the Other Names of Roller Bearing?

The other name of a roller bearing is known as a rolling-element bearing.

It is named so because, in this bearing, a load is carried by placing rolling elements between two races (bearing rings).  The relative motion of the bearing rings rolls the rolling elements with little sliding and rolling resistance.

18. What Is the Difference Between Ball Bearing and Roller Bearing?

19. How to Prepare Roller Bearing for Mounting and Dismounting?

Preparations: 

1. First of all you must sponge the mating surfaces and clean seats of anti-corrosive oil.
2. Wash out contaminated and used roller bearings.
3. Do not rework the bearing. It can result in the bearing’s failure before time. There will also chance of grit entering the roller bearing.
4. You should keep the work area dry and free from dust.
5. You should check the mating parts before the mounting of the bearing.
6. Also inspect housing tolerances and shaft.

You should obey the following rules before mounting and dismounting the bearing.

1. You should keep the mounting process neat and clean.
2. Protect the bearings from erosion and contamination.
3. You should use proper tools and devices for mounting.
4. You should eliminate the possibility of a mistake by determining the order of mounting activities.
5. You should also inspect the correctness of the bearing work.

An important point to note:

Always apply the mounting or dismounting force to the side of the bearing when mounting or dismounting the roller bearing.

Mounting and dismounting of a roller bearing

20. Why Does Roller Bearing Fail?

Following are the reasons for the failure of roller bearings.

1. Poor lubrication: The main reason behind the failure of roller bearings is lubricant contamination. When you see lubricant from your naked eye, it looks clean and free from pollutants. But in fact, it contains dust, dirt, and other tiny contaminants. 

Inadequate lubrication damages the roller bearings, and this damage is irreversible. Only replacement can reestablish the bearing to its unique state.

Contaminants can be incorporate in many ways. They can be introduced during lubricant production, during maintenance, because of fatigue, aging, and wear.

2. Corrosion is another reason that causes the failure of roller bearing.
3.  20% of failure is because of lengthy times between lubrication.
4.  15% contribution is of insufficient lubricant quantity.
5. 20% unsuitable lubrication.
6.  10% inadequate bearing selection.
7.  Improper bearing mounting
8. Manufacturing errors.
9.  Fit- tight fit: unnecessary loading of the rolling element when interference fits surpass the radial clearances at working temperatures.

Loose fit is caused by micro-motion between fitted parts.

10.   Excessive loads.
11. Improper mounting: Roller bearings mounted by smearing compression to the inner ring or outer race, poor tight fits, and loose shaft.
12.  Misalignments.

Roller bearing failure

21. How and When to Use Roller Bearing?

Roller bearings are alternative to ball bearings. You can use the roller bearing when carrying heavy loads. These types of bearings provide a large contact area and distribute the load evenly. 

These bearings can withstand high forces and are less susceptible to failure. Lower speed is another working condition that is suitable for roller bearing. 

Roller bearings work by using a shaft and cylinders (rollers). They use shafts in a much greater hole, and the cylinders fill in between the hole and shaft. 

Each roller behaves as a log when the shaft takes a turn. The rollers cannot fall out from under the load because of the shape that is round.

Working of a roller bearing

22. What Type of Grease Is Used in Roller Bearing?

The advantage of using grease instead of oil as a lubricant in roller bearing is that it remains in place and does not require monitoring. It does not leak and progresses sealing. While choosing grease, you should keep in mind the grade level for the operating temperature. The grade level indicates the stiffness of grease. Grade 0 and 1 is an indicator of soft grease and is used at low operating temperatures. Grade 2, 3, and 4 indicate stiff grease and are used at high temperatures. 

Following are the different types of grease used in roller bearings.

1. Lithium– used at high temperatures.
2. Benton clay– bears heavy loads at high temperatures.
3. Calcium– have resistance to corrosion, use at low temperature.
4. Sodium– cheap, medium-high temperature.
5. Synthetic– very expensive and very high temperature.

23. What Is the Role of Sealing Roller Bearing?

Sealing of roller bearing retains the lubricant inside the bearing and prevents harmful foreign particles from entering the bearing gap. Seals protect the function of bearings. Sealing can save money and space (by avoiding external sealing), extend the re-lubrication interval by keeping lubricant at its place and makes the bearing easy to handle. 

There are two sealing lips-outer lip and inner lip. The outer lip of sealing repels the contaminant particles and protects the bearing. Inner lip forms the actual seal. It increases the life span of a bearing. 

Types of sealing:

1. Gap seals- use to thin the gap between housing units and shaft.
2. Labyrinth seals
3. Rubbing and non-rubbing seals.

Sealed roller bearing

24. What Are the Seal Types of Sealed Rolling Bearing?

1. Contact seals: It is also known as lip seal. This seal continuously applies pressure on the inner ring of the bearing and makes direct contact with the inner ring. This creates difficulty for dust particles to reach the internal parts of the bearing. 
2. Non-contact seals: These types of seals are stable to the outer ring of a bearing and are not applicable to pressure the inner ring. It produces less friction than contact seals because of a lack of contact with the inner ring. These types of seals also prevent over-heating.
3. Labyrinth seals: These seals associate contact and non-contact seals in a single section. This creates difficult paths for contaminants that prevent the dust particles from entering the bearing. Labyrinth seals have multiple parts. One piece is not able to move, and the other peace moves with the system. The other two elements form a difficult path for substances that creates difficulty for them to enter or escape the bearing.

Sealed spherical roller bearing

25. What Are the Characteristics of Roller Bearing?

Following are the significant characteristics of roller bearings:

1. 1. They have a slight difference between the starting and running torque.
2. The roller bearing structure is not complex, so the inspection, maintenance, and replacement are easy.
3. They can carry both axial and radial loads independently.
4. These bearings can work significantly under variable temperatures.
5. They can produce a negative clearance by preloading and attain better rigidity.

26. On What Factors the Selection of Roller Bearing for installation depends?

The selection for installation depends on the:

1. The type of load.
2. The nature of the load
3. Nature of environment where the roller bearing is working.
4. Probability of the bearing
5. Speed of the shaft.

27.  What Kind of Steel Is Used in Roller Bearings?

SAE 52100: It is the most commonly used type of steel. The chrome steel is used in roller bearings like tapered roller bearings. 

Rollers, outer and inner rings of roller bearings are made up of this steel. It has a high carbon and hard surface to resist contact fatigue.

Stainless steel has a high content of chromium that makes them resistant to corrosion. A passive film is created by the reaction of chromium with oxygen and forms a layer of chromium oxide. This layer resists surface corrosion.

Stainless bearings AISI 440C has good corrosion resistance. Its load-carrying capacity is low because of its lower hardness. These types of steel are helpful in a wide range of temperatures and can easily withstand high temperatures.

ACD34/ X65Cr13 – stainless steel: These steels have low carbon and chromium content than AISI 440C. These steels have low noise characteristics. 

Martensitic stainless steel SV30: This steel is modified by reducing its carbon content. It is a steel of high strength and hardness.

28. What Are the Characteristics and Uses of LLG Self-Aligning Roller Bearings?

You can mount the inner and outer rings separately for the detachable LLG self-aligning roller bearings. You must check, with care, inner and outer rings are properly centered when the shaft is loaded with the inner circle in place into bearing housing.

LLG roller bearings assist in the folding of the shaft by fasteners. These bearings can resist radial loads, bidirectional axial loads, and impact loads. They can be applied to mechanical appliances like industrial machinery, paper-making machinery, and vibrating screens.

LLG self-aligning roller bearing

29. What Are the Advantages of Roller Bearing?

1. The mechanical efficiency of the roller bearing is high, and it is easy to start.
2. The power depletion and resistance to friction is less.
3. It is easy to install and disassemble. It has a standard size and easy to repair.
4. The axial size of a roller bearing is narrow, and the weight is light.
5. It has a long service life and high precision.
6. The efficiency of production is high.
7. The quality is reliable, and it is suitable for mass production.

30. What Are the Drawbacks of Roller Bearing?

Following are the drawbacks of roller bearing:

1. These bearings are costly.
2.  These types of bearings produce a lot of noise.
3.  The structure of the bearing seat is intricate.
4. These bearings eventually fail even they are sealed well, installed well, and lubricated well. Its reason is the fatigue of the rolling contact surface.