By selecting the right bearing for applications, it is important to distinguish needle roller bearing and ball bearing. Although both types are designated for the decrease of friction and for providing quiet and seamless rotational motion, their design, load bearing capability and usage are unique. In this article, you will discover the characteristics, pros and cons, and possible application fields of needle roller bearings and ball bearings.
What are Needle Roller Bearings?
Needle bearings are a kind of roller bearing with long, slender cylindrical rollers that are longer than their diameter, which are called needles. These needles have a length-to-diameter ratio that ranges from 3:1 to 10:1, thus enabling greater interaction between the rolling elements and the bearing rings. This design leads to higher load-carrying capacity than those provided by conventional ball bearings.
Components of Needle Roller Bearings
Needle Rollers: The rollers offer the main real estate for the load to be borne by. They are usually made of hardened steel to enable them to bear high stresses.
Needle Cage: This component assists in positioning and immobilizing the needle rollers in the best arrangement to ensure that they are equally spaced.
Outer Race: Made preferably from steel or brass, the outer race is the bearing that completes the path where the needle rollers roll over.
Inner Race: Sometimes, inner race is incorporated but in some other designs the shaft is utilized as the inner race. NSAR Bearings provides premium needle roller bearings for industrial machinery and can provide OEM customization and brand cooperation processing.
Advantages of Needle Roller Bearings
High Load Capacity: Needle roller bearings are capable of taking high load radial because of their large contact area.
Space Efficiency: They are suitable for uses that require little space since they can be set in a compact order.
Low Friction: They have low friction resistance and hence consume less power and are mechanically very efficient.
Versatility: Needle bearings come in several types, radial, thrust, and mixed bearings, making them appropriate for many uses.
Disadvantages of Needle Roller Bearings
Cost: Needle roller bearings are generally more costly than ball bearings because of the geography and material characteristics of their design.
Noise: It is sometimes limited in use by its ability to generate more heat and noise than the other bearing types.
Misalignment Sensitivity: Needle roller bearings are less tolerant regarding misalignment in most cases than ball bearings.
What Are Ball Bearings?
Ball bearings are the type of rolling-element bearings that employ balls to retain the gap between the bearing races. This design minimizes the rubbing contact and makes the bearing capable of taking both radial as well as axial loads. Ball bearings can be seen in a lot of applications, which include automobiles and industrial products.
Components of Ball Bearings
Balls: The spherical elements are responsible for rolling action and normally are manufactured from steel or ceramic material.
Outer Race: The outer race is a circular component in which balls are accommodated with the possibility of rolling.
Inner Race: The inner race is fixed on the rotating element, for instance a shaft or hub of a bearings’ system.
Cage: There is a cage or a separator that maintain the balls in a position they should not touch each other.
Advantages of Ball Bearings
Low Friction: Ball bearings have a low frictional resistance, therefore they are not prone to generating heat and abrasion, thus they last longer.
High-Speed Capability: High speed is possible because they are less abrasive and do not consume much force when in operation.
Tolerance to Misalignment: Compared with the spherical bushings, the ball bearings are more tolerant in terms of the angular misalignment between the inner and outer races.
Versatile Designs: They come in a variety, which includes radial, angular contact, and thrust ball bearings among others.
Disadvantages of Ball Bearings
Lower Load Capacity: Needle roller bearing has more load-carrying capacity than ball bearings for the same size due to point contact type of bearing.
Heat Generation: In high loaded applications, ball bearings create additional heat that could be controlled with the use of cooling systems.
Cost of High-Performance Options: Ceramic or stainless steel super precision ball bearings suited for high stress applications may be expensive.
Key Differences Between Needle Roller Bearings and Ball Bearings
Load Capacity
In applications that put high load, needle roller bearings perform well. Due to their large contact area, they are well suited to provide high radial loads. On the other hand, bearing balls are recommended for low load conditions hence they are well used in high speeds but not in strength operations.
Design and Structure
There are a lot of differences in the design of needle and ball bearings. A needle roller bearing features roller that has an elongated cylindrical shape to increase the contact surface area. Balls on the other hand are rounded which makes them even smaller and therefore gives point contact in ball bearings. This structural difference is reflective of their performance parameters.
Speed and Friction
Ball bearings are typically more suitable for high speed motion since the frictional force absorbed by them is relatively low and the system is less noisy. Needle roller bearings though effective may not possess the same high speed application possibilities as ball bearings. Nevertheless, needle roller bearings have low friction and can therefore be used in many applications.
Applications
Needle roller bearings are used in applications of machines such as gear pumps, automotive transmissions, compressors and others, where space is limited and shear loads are high. They are also used in aerospace and industrial equipment industries where reliability and productivity are easily valued.
Ball Bearings are used in a great range of uses such as electric motors, power tools, gearboxes as well as other equipment that demands high speed and low slippage. They are also found in household appliances.