Rolling-element bearings Manufacturers online

Rolling-element bearings are important components in mechanical engineering and industry that serve to support rotating or moving parts and reduce friction.

They ensure that parts such as shafts, axles or other moving components can move precisely, with low friction and a long service life.

Below you will find an overview of the structure, function and types of rolling-element bearings, as well as an overview of their areas of application, their advantages and information on maintenance and care:

Structure of Rolling-element bearings:

The structure of rolling-element bearings consists of several main components that work together to enable low-friction rotary motion.

1. Inner ring: The inner ring is the inner circle of the bearing that is mounted directly on the shaft. It normally rotates with the shaft and provides a raceway for the rolling elements.
2. Outer ring: The outer ring is the outer circle of the roller bearing and is installed in the housing. It normally remains stationary and also provides a raceway for the rolling elements.
3. Rolling elements: The rolling elements are the rolling parts in the bearing. They are located between the inner and outer ring and roll along the raceways to enable rotation and minimize friction.
4. Cage (retainer): The retainer is a component that keeps the rolling elements evenly spaced apart and controls their movement. It ensures that the rolling elements remain evenly distributed and prevents them from touching or rubbing against each other.
5. Seals or covers (optional): Some rolling bearings are equipped with seals or covers that protect the rolling elements and raceways from dirt, dust and moisture. These seals can be fitted either on both sides of the bearing or only on one side.

How rolling-element bearings work:

Rolling-element bearings minimize friction between two moving parts (usually a shaft and a housing) by replacing the plain bearing principle (where two surfaces slide against each other) with the rolling bearing principle. Rolling elements such as balls, cylinders or cones roll between the bearing components and prevent direct contact between the moving parts.

Types of rolling-element bearings:

There are different types of rolling-element bearings designed for specific applications. Here are some important types:

1. Ball bearings: Here, spherical rolling elements roll between the inner and outer rings. Ball bearings are versatile and suitable for high speeds, but they are less able to withstand higher radial loads than roller bearings.
2. Cylindrical roller bearing: Uses cylindrical rollers as rolling elements and can support high radial loads. Due to the linear contact between the rolling element and raceway, they are very resilient.
3. Needle roller bearings: A special type of cylindrical roller bearing in which the rollers have a very small diameter. Needle roller bearings are particularly compact and are suitable for radial loads in confined spaces.
4. Tapered roller bearing: Uses tapered rollers that are suitable for radial and axial loads. The tapered shape ensures that the bearing is designed for combined loads and is often used in vehicle axles.
5. Axial roller bearing: Specially designed for high axial loads and offers a high load carrying capacity with loads acting parallel to the axle.

Use of rolling-element bearings:

Rolling-element bearings are used in almost all technical and industrial applications. Here are some of the main areas of application:

1. Automotive industry:
Rolling-element bearings are widely used in vehicles, for example in wheels, gearboxes, motors and steering mechanisms. Tapered roller bearings are used in wheel hubs, for example, to support radial and axial loads in road vehicles.

2. Mechanical engineering:
In machine tools and production plants, bearings ensure the precise movement of shafts, spindles and rotating parts. Cylindrical roller bearings are ideal here due to their high load capacity and stability.

3. Electric motors and generators:
Ball bearings that can handle high speeds and moderate loads are often used in electric motors. The bearings contribute to the stability and durability of the motors.

4. Conveyor technology:
Bearings are used in conveyor systems and belt drives to support the rotating components and reduce friction. They increase the efficiency of the drive and extend the service life of the system.

5. Aerospace:
Special high-performance rolling-element bearings that can withstand extreme loads, temperature fluctuations and vibrations are used in aircraft, satellites and space probes. Ball and cylindrical roller bearings are frequently used here.

6. Agricultural and construction machinery:
Rolling-element bearings are common in tractors, excavators and other heavy-duty machinery as they can handle heavy radial loads and severe operating conditions.

Advantages of rolling-element bearings:

• The rolling contact of the rollers or balls significantly reduces friction compared to plain bearings.
• Lower friction leads to more efficient operation and lower energy losses.
• Rolling-element bearings have a long service life and offer stable performance with proper lubrication and maintenance.
• Rolling-element bearings in particular are suitable for high loads, making them ideal for industrial applications.
• Some types, such as tapered roller bearings, can support radial and axial loads simultaneously.

Maintenance and care of rolling-element bearings:

• One of the most important maintenance tasks is regular lubrication to reduce friction and wear. This can be done with grease or oil, depending on the operating conditions and the requirements of the bearing.
• Bearings should be kept clean and free of dust, dirt and other foreign particles to minimize abrasion.
• Regular monitoring and condition diagnostics (e.g. vibration analysis) can detect problems at an early stage and prevent costly failures.

In summary, it can be said that rolling-element bearings are used in almost all areas of mechanical engineering and industry due to their versatile functionality and load capacity. They enable low-friction, reliable and precise movements and are designed for high operating requirements, making them indispensable components in technology.

Below is an overview of the most important points that should be considered when purchasing rolling-element bearings:

When purchasing rolling-element bearings, it is important to consider various technical and operational factors to ensure that the bearings meet the requirements of your application and ensure a long service life.

• There are different types of bearings depending on the direction and type of load. For example, cylindrical roller bearings are ideal for high radial loads, while tapered roller bearings can support combined (radial and axial) loads. Ball bearings are suitable for high speeds with moderate loads.
• Determine whether the bearing must primarily support radial or axial loads (or both) and select the bearing accordingly.
• Check whether the bearing must operate in high or low temperatures and ensure that the selected bearing material and lubrication can withstand these temperatures.
• Dynamic and static load ratings indicate the load the bearing can support when moving (dynamic) and when stationary (static). These load ratings should be higher than the actual load in the application to ensure a long service life.
• Use calculations (such as L10 life) to estimate the bearing life under the specific load conditions. The manufacturer can assist you with the calculation to select the correct bearing for the intended service life.
• The maximum speed of a bearing is limited by its design and lubrication. If the bearing must operate at high speeds, make sure that the bearing is designed accordingly to avoid overheating and premature wear.
• Ball bearings are generally suitable for higher speeds than roller bearings. So choose the right type of bearing for applications that require high speeds.
• Rolling-element bearings are often made of high-quality bearing steel, which is sufficient for most applications. Stainless steel or ceramic bearings are also available for more demanding environments.
• If the bearing is used in corrosive environments (e.g. moisture, chemicals), a corrosion-resistant material or a special coating (such as zinc or nickel) is required.
• In high-speed applications or extreme temperatures, hybrid bearings (ceramic rolling elements with steel rings) can be advantageous as they offer higher temperature and wear resistance.
• Choose between grease or oil lubrication depending on the requirements of the application. Grease lubrication is often maintenance-free and suitable for low to medium load applications, while oil lubrication is more suitable for high temperatures and high loads.
• Bearings can be open or fitted with seals/covers. Seals protect the bearing from contamination and moisture. Covers are less tight, but still provide basic protection. Choose a seal that suits the environment (e.g. dusty or humid environment).
• Find out about the recommended lubrication intervals and maintenance requirements. Some bearings are maintenance-free and have lifetime lubrication, while others require regular lubrication.
• Precision bearings are required for applications with high demands on accuracy and smooth running, such as in machine tools or high-speed motors. The tolerance classes are defined by standards such as ISO or ABEC.
• Bearings with higher precision classes have lower concentricity tolerances and are less susceptible to vibrations and deviations. So choose the precision according to the accuracy required by the application.
• Make sure that the bearing comes from a reliable and certified manufacturer that complies with standards such as ISO 9001 for quality management.
• If your industry has specific requirements (e.g. aerospace, automotive), choose bearings that meet the relevant certifications and standards.
• Check that the bearing is designed for easy and precise mounting. Some bearing types require special tools or expertise for mounting.
• Some applications require preload adjustment or axial displacement. Choose bearings that allow easy adjustment in order to optimally distribute loads and vibrations.
• Inexpensive bearings may appear attractive at first glance, but may have a shorter service life or fewer protection mechanisms. Weigh up the price against quality, durability and maintenance requirements.
• Especially if you need replacement bearings, make sure that the bearing can be easily reordered in the future and that the manufacturer offers reliable delivery times.
• Check the availability and cost of spare parts and maintenance products such as seals and lubricants.
• An experienced supplier will provide technical support and advice to help you choose the right bearing. Ask for calculations or technical data sheets to help you decide.
• Some suppliers offer training in the installation and maintenance of bearings. This can be helpful to maximize bearing life.
• Some suppliers offer condition monitoring, such as vibration analysis and regular inspections. These services help to continuously monitor the condition of the bearings and prevent failures.

These criteria will help you to select the optimum bearing for your application, reduce operating costs and ensure a long service life.

Rolling-element bearings can be purchased from various suppliers. Comprehensive information about manufacturers and suppliers of Rolling-element bearings from all over the world can be found on Exportpages.