Rolling element bearings are a widely used machine elements and they are used to allow rotation of or around shafts in many different machines, such as bicycle, cars, electric motors, aircraft turbines, mills, etc. The main advantage of rolling bearings is their low friction, since the resistance to the motion is only driven by the rolling friction which is much lower typically than the sliding friction. The design of the rolling-element bearings ensures their reliability while reducing the impact of variations in speed, temperature, load, and lubricating conditions. At the same time, the maintenance required for such bearings is typically much easier as compared to the other types of bearings. All these features coupled with availability and efficiency of the bearings contribute to a wide use of rolling element bearings in various applications.
Selection of Rolling-Element BearingBearing selection is a process of matching of a particular bearing and the application requirements, including load, misalignment, speed, and torque.
Rolling-element bearings support the load via the contact existing between the rolling elements and the raceways. During the rotation, a motion of one raceway relative to another raceway occurs. In general, a bearing consists of an inner raceway, outer raceway, rolling elements and usually a cage, as shown in the figure below. The cage is required to maintain appropriate spacing between the rolling elements so that they do not come into contact with each other.
Rolling-element bearings exist in many different forms with each one having a unique set of features. The suitability of a rolling-element bearing to a particular application is based on the match between these features and the application requirements. In such a context, it becomes essential to consider certain factors when selecting the most suitable type of bearing. According to SKF (the leading rolling element bearings manufacturer, link?) catalogue, the following are key factors for the optimum bearing selection:
In addition to these factors, it is essential to consider not only the bearing itself, but the whole assembly, like shafts and housing. Thus, for an optimum bearing selection, one must also consider the following factors:
The rolling element bearings can be classified in various ways, e.g.. by the direction of the carried load, roller geometry, or by a particular feature of the bearing. However, the most common classification is based on the geometry of the rolling elements:
The most common type is the ball bearing, their rolling elements are ball shaped (see the figure above). The contact area is relatively small in this case and, as a result, these bearings are quite efficient at high rotating speeds, showing the lowest friction torque. Additionally, they are very cheap to manufacture. However, the disadvantage of a ball bearing is its limited load-carrying capacity, especially in radial direction.
The cylindrical roller bearings contain cylindrical rollers, see the figure above. In this case the contact area between a roller and the raceway is larger as compared to the ball bearings. This makes this type of bearings to outperform other types of bearings in radial load carrying capacity. Simple roller geometry allows a tight manufacturing tolerance and rollers are typically crowned at the edges to mitigate the roller-end edge stresses. In addition, they have a relatively low-friction torque and medium speed capability. At the same time, their performance is quite sensitive to misalignment and they wear out quickly when the alignment is poor.
Turning to tapered roller bearings, these types of roller geometry bearings have tapered rollers as the rolling elements. Like cylindrical roller bearings, they also have a relatively large contact with the raceways and are guided by a thrust flange at the large roller ends. In terms of load-carrying capacity, these roller bearings support heavy loads in the axial or radial directions. This makes them possess the highest combined load-carrying capacity. Notably, the design of these rollers requires the machining of both the roller large-end and the roller body thereby making them the most expensive bearing to manufacture, but quite advantageous in terms of durability and fatigue resistance.
Moving to spherical roller bearings, this type of bearings utilizes double-row barrel-shaped rollers as the rolling elements. The standard design of these roller bearings assumes the radius of the roller that aligns closely to the radius of curvature of the outer raceway. This geometry assumes an elongated and mostly truncated elliptical contact with both the raceways. Their ability to support combined axial and radial loads or radial loads is above average and these bearings are durable, highly resistant to fatigue and rather tolerant to misalignment. At the same time, they are unsuitable for high-speed applications due to highest friction torque.
Finally, the needle roller bearings have rolling elements that are long and cylindrical. They result in long line contacts with the raceways similar to the case with the cylindrical roller bearings. However, due to their length, they have a low tolerance to misalignment and increased risk of roller sliding. As a result, these types of roller geometry bearings have high frictional torque and the lowest limiting speed. The needle roller bearings are also quite disadvantaged in handling the combined axial and radial loads. However, they possess an attractive trait of compactness as the volume requirement for their installation is relatively small and most significantly, their manufacturing cost is low making them affordable.
Selection processThe selection of an appropriate bearing for a particular application requires a consideration of the bearing features and the application requirements that need to be fulfilled. Several attributes differentiate the types of bearing namely the loading conditions, the speed, the bearing torque, tolerance to misalignment, etc. Nowadays, bearing manufacturers provide the users with the online tools to select a suitable bearing for a given application. An example of such tool is Bearing Select from SKF link. This is a very simple and fast way of getting a right bearing for the given use.
ApplicationsThe features possessed by the rolling-element bearings make them suitable for certain applications. For instance, cylindrical roller bearings are popular in rolling mills, machine tool spindles, and mid- to heavy-duty electric motors. High radial load-carrying capacity, precision, high support stiffness, high-speed capability among others makes them suitable for such applications.
The ball bearings are used in electric vehicles motors where the load is usually combined or radial and relatively low, while the speed range is rather broad, reaching quite high levels. The bearings are also found in light-duty gearboxes, conveyor rollers, and small vehicles. The important aspects for the selection include light load, dual load-carrying capacity, and low cost.
The tapered roller bearings represent a better choice when looking for a bearing that supports combined axial and radial loads as well as high load. As a result, they are used in the wheels of off-road vehicles, passenger cars, gearboxes of marine drives, landing wheels of aircrafts, printing presses, other transmission systems, and machine tool spindles. Particular factors such as heavy load carrying capacity and adjustment ability that facilitate precision and stiffness should be considered during the selection process.
The spherical roller bearings are utilized in windmills, rolling mills, paper mills, large industrial gearboxes and others. They have efficient misalignment ability and heavy radial load carrying capacity.
Finally, needle roller bearings are utilized in automotive transmissions due to their compactness and affordability. Some industrial gearbox and pump manufacturers also use them.
Roller bearings may not be the most glamorous components in machinery, but they play a crucial role in keeping various industries moving smoothly. Whether you&#;re in manufacturing, automotive, or any sector relying on machinery, understanding roller bearings and choosing the right type for your application can significantly impact performance and efficiency.
At IBT Industrial Solutions, we understand the importance of these often-overlooked essential components of machinery. In this comprehensive guide, we&#;ll take you on a journey through the world of roller bearings. We&#;ll help you understand what roller bearings are, their different types, and why choosing the right one is essential. Plus, we&#;ll introduce you to TRITAN® Bearings, our trusted partner, renowned for its diverse range of roller bearing products.
Roller bearings are mechanical components designed to reduce friction between moving parts, facilitating smooth motion in machinery. Unlike plain bearings, which slide, roller bearings use cylindrical, needle-shaped, or tapered rollers to carry and distribute the load. This rolling action minimizes friction, heat generation, and wear, making roller bearings essential for the efficient operation of various industrial applications.
Roller bearings are found in a wide range of machinery, including conveyor systems, automotive transmissions, industrial equipment, and even household appliances. They provide support and reduce wear and tear, ultimately improving the longevity and performance of machines.
Roller bearings come in various types, each designed to meet specific application requirements:
Spherical Roller Bearings:
These
bearings
feature spherical-shaped rollers and are known for their ability to handle heavy radial and axial loads. They are often used in applications where misalignment and shock loads are common, such as in mining and construction equipment.
Cylindrical Roller Bearings:
Cylindrical rollers are used in these
bearings
, which are particularly suitable for applications with high radial loads. Industries like manufacturing, steel production, and paper mills rely on
cylindrical roller bearings
to maintain precision and reliability.
If you want to learn more, please visit our website Beijing SKF.
Needle Roller Bearings:
Needle roller bearings
use long, thin rollers with a high length-to-diameter ratio. They excel in applications with limited space and high radial load requirements, such as in the automotive and aerospace industries.
Tapered Roller Bearings:
Tapered rollers make these
bearings
suitable for applications requiring both radial and axial load support. They are commonly used in automotive wheel hubs, gearboxes, and other industrial equipment.
Spherical roller bearings are designed with barrel-shaped rollers. This unique design allows them to accommodate heavy radial and axial loads while handling misalignment. They are ideal for applications where the shaft or housing may not be perfectly aligned, providing reliability and durability in industries such as mining, construction, and heavy machinery.
TRITAN Bearings offers a range of spherical roller bearings known for their high load-carrying capacity, robust construction, and resistance to harsh operating conditions. These bearings are essential for ensuring the smooth operation of machinery subjected to varying forces and misalignment challenges.
Cylindrical roller bearings consist of cylindrical rollers that distribute load evenly across their length. This design allows them to handle high radial loads with excellent precision, making them indispensable in industries such as manufacturing, steel production, and paper mills.
TRITAN Bearings&#; cylindrical roller bearings offer superior performance, reliability, and extended service life. They are engineered to meet the stringent demands of heavy-duty applications, ensuring machines operate efficiently and with reduced downtime.
Needle roller bearings are characterized by their slender cylindrical rollers with a high length-to-diameter ratio. This design allows them to provide high radial load capacity in tight spaces. Needle roller bearings are commonly found in compact machinery, including automotive transmissions, where precision and efficiency are critical.
TRITAN Bearings&#; needle roller bearings are crafted with precision and care, making them ideal for applications where space constraints demand compact yet high-performance solutions. These bearings excel in situations where standard roller bearings may not fit or provide the necessary precision.
Tapered roller bearings feature rollers with conical shapes that create a taper along their length. This design enables them to handle both radial and axial loads efficiently. Tapered roller bearings are commonly used in applications like automotive wheel hubs, gearboxes, and other machinery requiring a combination of load-bearing capabilities.
TRITAN Bearings&#; tapered roller bearings are engineered to provide the necessary reliability and efficiency in motion. In automotive and industrial equipment, where both radial and axial loads come into play, these bearings are essential for smooth operation and extended service life.
When choosing the right roller bearing, several critical factors must be considered:
Load Capacity:
Determine the magnitude and direction of the load the
bearing
will support, whether it&#;s radial, axial, or a combination of both.
Speed:
Consider the rotational speed of the application as excessive speed can impact
bearing
performance.
Environmental Conditions:
Evaluate the operating environment, including temperature, humidity, and exposure to contaminants, as these factors can affect
bearing
life.
Alignment and Misalignment:
Determine if the application requires the
bearing
to handle misalignment, and select a suitable type accordingly.
Space Constraints:
Consider the available space within the machinery, as compact solutions like
needle roller bearings
may be necessary in tight quarters.
Precision Requirements:
Some applications demand high precision, such as those in the medical or semiconductor industries.
Choosing the right roller bearing involves balancing these factors to ensure optimal performance and longevity for your specific application.
When it comes to sourcing high-quality roller bearings for your industrial and mechanical needs, TRITAN Bearings emerges as a standout supplier. With a diverse range of roller bearing products, TRITAN Bearings ensures that engineers, maintenance professionals, and businesses can find the ideal roller bearings to meet their specific operational requirements.
TRITAN Bearings offers an extensive selection of roller bearings, including spherical roller bearings, cylindrical roller bearings, needle roller bearings, and tapered roller bearings, each tailored to excel in various applications across multiple industries. These bearings are known for their durability, precision engineering, and ability to perform under demanding conditions.
At IBT, we understand that selecting the right roller bearings is pivotal for ensuring optimal machinery performance. Our experienced and knowledgeable team is ready to assist you in identifying the best roller bearings for your specific applications, guaranteeing reliability and longevity.
Our commitment to customer satisfaction extends beyond just providing quality products; it encompasses personalized guidance, technical expertise, and a dedication to meeting your unique needs. Reach out to our team today, and let IBT Industrial Solutions help you find the right roller bearings for your application&#;s precise requirements.
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If you want to learn more, please visit our website SKF Needle Roller Bearing.
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