{"id":20672,"date":"2026-10-07T17:26:58","date_gmt":"2026-10-07T08:26:58","guid":{"rendered":"https:\/\/cik-ele.com\/?p=20672"},"modified":"2026-10-08T17:42:12","modified_gmt":"2026-10-08T08:42:12","slug":"bearing","status":"publish","type":"post","link":"https:\/\/cik-ele.com\/en\/column\/bearing\/","title":{"rendered":"WHAT ARE BEARINGS? AN EASY-TO-UNDERSTAND GUIDE TO HOW THEY WORK, TYPES, HOW TO CHOOSE THEM, AND LIFESPAN"},"content":{"rendered":"

Bearings, used in motors and industrial machinery, are critical components that support rotating shafts while minimizing friction to ensure smooth operation. If the wrong type of bearing is selected or it is not chosen properly, vibration<\/a>, heat generation, and wear<\/a> can occur, potentially leading to reduced machine performance and a shorter lifespan.<\/p>\n

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There are various types of bearings, and there are numerous factors to consider, such as structure, load direction, and rotational speed. In this article, we\u2019ll provide an easy-to-understand explanation of everything from the basic mechanisms and types of bearings to how to select them, how to assess their lifespan, and maintenance methods.<\/p>\n\n\n\n
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Supervised by: C.I. TAKIRON Corporation Electronic Devices Sales Group<\/u><\/strong><\/p>\n

This article has been supervised based on the advanced technical expertise and insights we have cultivated since our founding in 1919 as a leading company in plastic processing. Our department continuously analyzes market trends and the latest technologies in ultra-compact, high-precision micro motors, focusing on providing high-value-added information to designers and developers. As a team of experts with in-depth knowledge of product characteristics, we support our customers\u2019 problem-solving and technological innovation by delivering accurate and practical content.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

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What Are Bearings?<\/h2>\n

\"WHAT<\/p>\n

A bearing is a mechanical component that supports a rotating shaft while bearing a load. It keeps the shaft in the proper position while minimizing friction in the rotating parts, thereby ensuring smooth motion.<\/p>\n

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Bearings are used in a wide range of machinery, including automobile wheels and transmissions, as well as motors, pumps, conveyors, washing machines, fans, and robots. The English word \u201cbear\u201d means \u201cto support,\u201d and bearings are one of the essential components for ensuring the stable operation of rotating machinery.<\/p>\n

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The Role of Bearings<\/h3>\n

The primary role of a bearing is to support a rotating shaft while minimizing friction between the shaft and surrounding components. If the shaft and surrounding components rub directly against each other, sliding friction can easily cause wear and heat generation.<\/p>\n

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In rolling-element bearings, the shaft is supported by rolling elements such as balls or rollers, which replaces sliding friction with rolling friction and reduces frictional resistance. Another important role is to maintain the proper position of the shaft and minimize runout and misalignment.<\/p>\n

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Since this also helps suppress friction, wear, and heat generation<\/a>, bearings can be considered essential components that support the stable operation of machinery.<\/p>\n

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Basic Structure of Bearings<\/h3>\n

Typical rolling bearings consist primarily of an \u201cinner ring,\u201d an \u201couter ring,\u201d \u201crolling elements,\u201d and a \u201ccage.\u201d The inner ring is mounted on the shaft side, and the outer ring is mounted on the housing side; the rolling elements\u2014such as balls or rollers\u2014roll between the two rings.<\/p>\n

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The cage serves to maintain the rolling elements at appropriate intervals and prevent them from coming into contact with one another. Depending on the product, some types are equipped with seals or shields to prevent the ingress of foreign matter and lubricant leakage.<\/p>\n

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Lubricants, such as grease, used inside the bearing are also important for reducing friction and wear and maintaining smooth rotation.<\/p>\n

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Main Types of Bearings<\/h2>\n

\"WHAT<\/p>\n

There are various types of bearings, and they can be classified based on multiple criteria\u2014such as the mechanism for supporting the shaft, the shape of the rolling elements, and the direction of the load\u2014rather than just a single standard. Since each type is suited for different operating conditions, it is important to understand their characteristics and select the one that best fits the application.<\/p>\n

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The following summarizes the typical classifications and characteristics of bearings.<\/p>\n\n\n\n\n\n\n\n\n\n
Classification<\/td>\n\u00a0Type<\/td>\nMain Characteristics<\/td>\n<\/tr>\n
Shaft Support Mechanism<\/td>\nRolling Bearings<\/td>\nSupports the shaft by rolling balls or rollers, thereby reducing friction<\/td>\n<\/tr>\n
Shaft Support Mechanism<\/td>\nSliding Bearings<\/td>\nThe shaft and bearing surface make sliding contact, and the shaft is supported using lubricants or other means<\/td>\n<\/tr>\n
Shape of Rolling Elements<\/td>\nBall bearings<\/td>\nUses balls; has relatively low friction and is suitable for high-speed rotation<\/td>\n<\/tr>\n
Shape of Rolling Elements<\/td>\nRoller bearings<\/td>\nUses rollers and is capable of withstanding heavy loads<\/td>\n<\/tr>\n
Load Direction<\/td>\nRadial bearings<\/td>\n\u00a0Primarily supports loads perpendicular to the shaft<\/td>\n<\/tr>\n
\u00a0Load Direction<\/td>\nThrust bearings<\/td>\nPrimarily support loads in a direction parallel to the shaft<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

The points of comparison vary depending on the classification method. Let\u2019s take a closer look at the differences between them from three perspectives: the mechanism for supporting the shaft, the shape of the rolling elements, and the direction of the load.<\/p>\n

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Rolling Bearings and Sliding Bearings<\/h3>\n

Bearings are broadly classified into \u201crolling bearings\u201d and \u201csliding bearings\u201d based on the mechanism used to support the shaft. Rolling bearings feature balls or rollers arranged between the inner and outer rings, with a structure that minimizes friction through rolling motion.<\/p>\n

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They have relatively low friction and are used in a wide range of applications, such as motors, machine tools, and automobiles. Sliding bearings rely on sliding contact between the shaft and the bearing surface, supported by lubricants or other means.<\/p>\n

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Their structure is relatively simple, and depending on the type, they are also used in applications subject to heavy loads or impacts. It is important to select the appropriate type based on factors such as rotational speed, load, and operating environment.<\/p>\n

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Ball Bearings and Roller Bearings<\/h3>\n

Rolling bearings are classified into \u201cball bearings\u201d and \u201croller bearings\u201d based on the shape of the rolling elements used. Ball bearings use spherical rolling elements and are characterized by contact with the raceway that is nearly point-like. Because they have relatively low friction, they are suitable for compact motors, home appliances, and precision equipment that require high-speed rotation and low noise.<\/p>\n

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Cylindrical roller bearings use rolling elements such as cylindrical, tapered, or needle-shaped rollers. Because they make linear contact with the raceway, they have a wide load-bearing surface and are used in industrial machinery, vehicles, and heavy equipment where high loads and high rigidity are required.<\/p>\n

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Radial Bearings and Thrust Bearings<\/h3>\n

Bearings can be classified primarily as \u201cradial bearings\u201d and \u201cthrust bearings\u201d based on the direction of the load they support. Radial bearings are designed to support radial loads acting perpendicular to the shaft. Examples include forces applied to the shaft by pulleys and gears.<\/p>\n

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Thrust bearings are designed primarily to support axial loads applied in a direction parallel to the shaft. They are used in applications where forces are applied in the axial direction, such as the thrust from a propeller.<\/p>\n

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When both radial and axial loads are applied simultaneously, it is necessary to select a type capable of handling combined loads, such as angular contact ball bearings or tapered roller bearings.<\/p>\n

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Main Applications of Bearings<\/h2>\n

\"WHAT<\/p>\n

Bearings are used in a wide range of machinery with rotating parts, including automobiles, machine tools, industrial machinery, robots, home appliances, precision equipment, and motors. Typical applications and the primary performance requirements are as follows.<\/p>\n\n\n\n\n\n\n\n\n\n
Application<\/td>\nExamples of Use<\/td>\nPrimary Performance Requirements<\/td>\n<\/tr>\n
Automobiles<\/td>\nWheels, transmissions, etc.<\/td>\nLoad-bearing capacity, impact resistance, durability<\/td>\n<\/tr>\n
Machine Tools<\/td>\nSpindles, feed mechanisms, etc.<\/td>\nRotational accuracy, high-speed rotation capability, rigidity<\/td>\n<\/tr>\n
\u00a0Industrial machinery<\/td>\nPumps, conveyors, motors, etc.<\/td>\n\u00a0Capability for continuous operation, durability<\/td>\n<\/tr>\n
Robots<\/td>\nJoints, rotary tables, etc.<\/td>\nRotational accuracy, space-saving design, and ability to handle combined loads<\/td>\n<\/tr>\n
Home Appliances<\/td>\nWashing machines, air conditioners, electric fans, etc.<\/td>\nThrust bearings<\/td>\n<\/tr>\n
Precision Equipment<\/td>\nMedical equipment, optical equipment, etc.<\/td>\nRotational Precision, Low Friction, Low Vibration<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

 <\/p>\n

The performance required of bearings varies depending on the application\u2014for example, rotational precision and high-speed operation in machine tools, and low noise and low vibration in home appliances. In the case of motors, it is also essential to select bearings based on factors such as rotational speed, load, and required lifespan.<\/p>\n

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When selecting a bearing, it is important to consider the characteristics of the machine in which it will be used and to clarify conditions such as load magnitude and direction, rotational speed, precision, and operating environment.<\/p>\n

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Key Considerations When Selecting Bearings<\/h2>\n

\"WHAT<\/p>\n

When selecting a bearing, it is important to comprehensively evaluate not only the type but also the actual load, rotational speed, mounting space, precision, and operating environment. Using a bearing that does not meet these conditions may lead to issues such as heat generation, vibration, or premature wear.<\/p>\n

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The main points to consider during selection are as follows.<\/strong><\/p>\n

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