A Guide to Precision Ball Bearings
A ball bearing is a bearing between an axle and a wheel with a ring of small solid metal balls reducing friction between the rotating and stationary parts. Precision ball bearings have higher standard precision levels than most components. In various applications, they employ at least two races to contain and transfer loads through the balls — with one race fixed and the other connected to the rotating assembly.
Precision ball bearings are used in different industries, including aerospace, health, manufacturing, automation, and commercial construction sectors. This article will discuss the functions, structures, and types of ball bearings used for various applications.
What Is a Ball Bearing Used For?
A ball bearing connects two parts and components that lie close to one another while providing minimal frictional resistance to motion. Usually, one of the components is a rotating shaft while the other is a stationary housing.
The balls rotate as a result of the rotation of the bearing races, lowering the frictional coefficient between them. The load capacity of the ball bearings is also lesser than that of other types of bearings of comparable size due to the smaller contact points between the races and the balls.
What Is the Basic Structure of a Ball Bearing?
A ball bearing comprises four major parts: two rings or races (outer and inner), balls or the rolling elements, and a retainer or the ball separator. The outer race is fixed and mounted into the housing, contributing to the transfer of radial load from the bearing to the housing. On the other hand, the inner race supports and directs the rotating shaft.
The rolling elements transport the load and distribute it across the pathways; they rotate at a different speed than the inner race but revolve around it. Lastly, the separator is positioned between the balls and functions as a barrier preventing them from colliding.
What Are the Different Types of Ball Bearings?
The following are the various types of ball bearings:
Radial Bearings
Also referred to as deep groove ball bearings, this type is one of the most commonly used bearings for various applications, including machinery and certain motors. They can carry axial and radial loads but are mainly employed when the primary load moves radially.
Electric motors are the most common industrial application of radial ball bearings to support loads and motion in axial directions between the housing and the shaft. They are also useful for industrial pumps where liquids shoot up, causing the axial load to switch directions momentarily before resuming its original orientation.
Radial bearings do not need to be purchased in pairs, making them an excellent option for applications with limited space.
Angular Contact Bearings
Angular contact bearings are asymmetrically designed to achieve high speeds and withstand radial-axial loads. Although they can only tolerate unidirectional axial loads, they can support loads that are not perpendicular to the bearing axis. In addition, they have one or both shoulders that are elevated and must be assembled with a thrust load for proper operation.
These bearings are ideal for gearboxes, electric motors, pumps, clutches, and other high-speed applications. They are also used in material handling, machine tools, steel mills, and wind energy.
Thrust Bearings
Thrust bearings are special rotary bearings that allow rotation between the parts. They are designed to support a predominantly axial load as they cannot handle the radial ones. They are also mounted directly on the seating surface, not the shaft or housing.
Thrust ball bearings are used in low-thrust applications with little axial load, such as automotive, generators, water turbines, heavy-duty machinery, industrial machinery, and mining and construction. Visit this page to learn more about the applications of thrust bearings.