Master Guide to Ball Bearings
Ball bearings are mechanical components that reduce friction between rotating elements to facilitate relative motion. They consist of a bearing race, a ball, and a retainer, where the balls minimize friction by rolling between the races. They are also used in various applications, including automotive, aerospace, medical, and defense industries.
For over 50 years, SPB-USA has been the leading manufacturer of precision ball bearings available in multiple sizes and load capacities! We are also certified in ISO 9000, ISO 9001, and ISO 14001, ensuring that our products are manufactured to the highest standards.
How Do Ball Bearings Work?
Ball bearings transfer loads between rotating and stationary components by combining rolling elements (usually balls) and races. The inner race transfers the load to the outer race, while the balls reduce friction and help distribute the load uniformly.
The inner race of a standard ball bearing is fixed on the shaft, while the outer race is located in the housing. The balls are arranged between them and maintained in position by a retainer or cage. When the shaft rotates, the balls spin and roll between the outer and inner races. Then, designed with a slight separation between them, they allow the balls to rotate freely.
As the load is applied to the bearing, the races deform slightly, and the balls are propelled against them. This transfers the load and reduces friction. Additionally, the bearings are routinely lubricated to enhance performance and are designed for use in various applications and operating conditions.
Ball Bearings Design and Construction
The typical components of a ball bearing are two races (inner and outer), rolling elements, a cage or retainer, and seals or shields. Its design and construction may vary based on the application’s requirements, such as load, speed, and working environments. It can also incorporate unique material selection, specialized geometry, and surface treatments to enhance performance.
For example, the races may be manufactured with high-precision tolerances to ensure a precise fit between them and the balls. The balls may also be made with hard materials — steel, ceramic, or plastic — to enhance durability and performance. Furthermore, the cage or retainer may be constructed from lightweight, corrosion-resistant materials to reduce weight and improve reliability.
Types of Ball Bearings and their Applications
The types of ball bearings vary based on a given system’s application and operating circumstances. They are also built to handle load, speed, and precision requirements.
Here are some of the most common types and their respective applications:
Miniature bearings are small-sized components used in applications where space is limited. They have a smaller diameter and total size than standard bearings but offer comparable support and functionality. In addition, they utilize the same materials and design principles as the standard ones. However, they are intended to meet the particular requirements of compact mechanical systems.
These bearings are widely used in manufacturing medical equipment, office supplies, and consumer electronics. They are also applied in the aerospace, instrumentation, and robotics industries. Other applications of miniature bearings include the following:
- Dental handpieces
- Fan motors
- Spindle motors
- Stepping motors
Flanged bearings are a form of rolling element bearing. They have a protrusion or flange on the outer race that helps to locate the bearing in a particular spot. The protrusion provides an additional surface area for mounting the bearing to a housing or support structure. This makes them suitable in applications where the bearing must be fixed in a certain place.
This type of bearing is available in various configurations, including deep groove, angular contact, and spherical roller. All of these components are frequently used in the following applications:
- Electric motors
- Rotary encoders
- Scanner motors
- Stepping motors
Stainless Steel Bearings
Stainless steel bearings have a high level of corrosion resistance due to their composition. Their unique characteristics include exceptional oxidation resistance, long-term durability, and the capacity to operate in harsh environments.
The following are the most common applications of stainless steel bearings:
- Food processing equipment
- Medical machinery
- Printing presses
- Textile machinery
Angular Contact Bearings
Angular contact bearings are rolling element bearings designed to handle both radial and axial loads. They have a high load-bearing capability and can support heavy loads in both the radial and axial directions. They also consist of an inner race, an outer race, and rolling elements that are in contact with both races.
Some examples of this bearing type’s applications are as follows:
- Boring heads
- Grinding spindles
- High-frequency spindles
- High-speed machinery
- Live centers
Thrust bearings can handle axial forces or those that act in the direction of the shaft. They are utilized to support heavy loads along the axis of rotation and prevent the shaft from moving axially. In addition, they consist of two flat surfaces, a flat cylindrical race and a matching washer, and rolling elements in contact with both surfaces.
Applications of thrust bearings include the following:
- Automotive transmissions
- Heavy-duty machinery
- Main axis of machining tools
- Turntables for vertical turning machines
Also referred to as thin-section bearings, extra-thin bearings have a reduced cross-section compared to standard types. This allows them to fit into spaces that are normally inaccessible. In addition, these components have a smaller mass, which can reduce the overall weight of the mechanical system.
Here are some of its applications:
- Heat rollers
- Medical instruments
- Robot joints
- Rotary encoders
- Stepping motors
Extra-miniature bearings are a type of miniature bearing with an even smaller size. As a result, they are typically compact and lightweight, allowing them to be utilized in areas with limited space. They can also endure heavy loads and work at high speeds, making them suited for systems requiring high precision, performance, and dependability.
This bearing type is frequently utilized in the following applications:
- HDD fan motors
- HDD spindle motors
- Pinch rollers
Maintenance and Inspection of Ball Bearings
Maintenance and inspection are essential for ensuring the bearing’s optimum operation and durability. They aid in identifying and preventing any problems, extending the component’s life, and maintaining its safe and effective operation.
Here are some practical care tips:
- Lubricate the bearings regularly: Grease or oil lubrication helps reduce friction and wear.
- Clean the bearings: Cleaning removes debris and contaminants that can harm the component and can be performed using a solvent or compressed air.
- Check for proper tightening: Ensure that the bearing components are properly tightened to avoid any looseness and misalignment.
- Inspect any visual damage: Regularly inspect the bearing for any visible signs of damage, such as cracks, deformities, or excessive wear.
- Measure the components: Always measure the parts of the bearing, such as the inner and outer races, balls, and seals, to ensure they are within specifications.
- Check for noise and vibration: Regularly monitor the bearing for any unusual noise or vibration, as this can indicate a more serious problem.
- Store the bearings properly: When not in use, store the bearings in a clean and dry environment to prevent contamination and damage.
- Replace the bearings if necessary: If a bearing shows signs of excessive wear, damage, or corrosion, replace it to ensure proper functioning and longevity.
SPB-USA: The Leading Manufacturer of High-Quality Ball Bearings
Since 1969, SPB-USA has had a long-standing reputation as a leading manufacturer of precision miniature and medium-sized bearings, offering both inch and metric dimensions. We specialize in producing chrome, steel, and stainless steel bearings and components, ensuring that we meet our customer’s needs in various industries.