Thin Section Bearings

With standard ball bearings, the width and thickness of the bearing increases in proportion to the bearing’s bore size. That’s not the case with thin section bearings because the cross section doesn’t change as the bore size increases. Because of this design, there is little change in the weight of a bearing even as the diameter of the application increases. Also, this supports weight reduction efforts while requiring less space than a standard ball bearing would need.  

• Their most distinctive characteristic is their smaller cross-section compared to standard bearings with the same bore diameter. 
• This results in a lighter and more compact overall package.
• It’s an advantage that’s crucial in space-constrained applications like robotics, medical devices, aircraft components, and gimbal systems.

It’s not the size of the cross-section alone that matters. Rather, it’s about the relationship, or ratio, of the cross-section to the bearing bore. If the cross section doesn’t increase in proportion to the bearing bore in a series of bearings, then it’s a thin section bearing series.

As the table below shows, thin section bearings from Schatz belong to a lettered product series and have a cross-section with a specific dimension. Within each series, the cross section remains the same for all the different bearing bore sizes. 

No. Thin section bearings can also reduce friction and prevent torque loss. Depending on the contact style, thin section bearings have plenty of load-carrying capacity. For example, the thin section four-point contact bearing that is used at the base of a robot’s arm can handle extreme moment loads at the base of the shaft.

Thin section bearings are used in applications where space is limited or weight is an important design consideration. These motion control products appear thinner than standard ball bearings because their cross-section does not become larger as bore diameter increases. By helping to reduce space and weight requirements, thin section bearings can reduce costs for applications ranging from aerospace and defense to automation and robotics – just to name a few.    

• Typically, it’s because a systems designer has reviewed the application requirements and determined that the critical performance aspects require a thin section bearing.
• When system compactness, weight reduction, precision, and performance are the critical performance aspects, thin section ball bearings should be considered.

• Thin-section ball bearings, with their reduced cross-section, allow for compact and lightweight system designs. 
• This can have cascading benefits, like decreased fuel consumption in aircraft or increased payload capacity in satellites.
• Another benefit is increased design flexibility.
• Due to their smaller cross-section, system designers have greater freedom for bearing placement.
• This results in the ability to get the bearing closer to the point of loading, which improves overall system performance.
• The smaller cross-section results in reduced ball size, and increased ball complement, leading to smoother rotation, lending itself to high precision applications.
• Their internal geometry is typically optimized to minimize internal losses, resulting in lower friction.
• The reduced cross-section can allow for a duplex set of angular contact bearings to fit within the same or smaller envelope than a single standard bearing with the same bore diameter.
• Duplex sets of angular contact bearings or four-point contact designs can support radial, axial, and moment loads simultaneously.
• This simplifies bearing selection, improving system robustness, and overall system stiffness in all load axes.

• The most significant disadvantage of thin section ball bearings is their reduced load capacity versus that of a standard bearing with the same bore diameter.
• They are also affected by the system around them to a greater extent than standard bearings.
• Thin section ball bearing rings, being smaller in cross-section, will conform to any imperfections in the shaft and or housing to a much greater than standard bearings.
• So, thermal variations in the system can result in changes to the bearing performance.
• Mounting thin section ball bearings can be more complex than mounting standard bearings.
• This is because they require precise shaft and housing fits.
• In general, thin section ball bearings are more expensive than standard bearings due to their complex design and manufacturing process.

Yes. Thin section bearings can be radial, angular contact, or four-point contact bearings.

• Radial thin section ball bearings are used mainly with radial loads, but can also handle minimal axial, reversing, and moment loads.
• Angular thin section contact bearings are recommended for higher thrust and axial loads; however, these thin section bearings may also be able to handle radial and combined loads.
• Four-point contact thin section bearings have a raceway that creates four points of contact for handling moment and reversing loads. They are not recommended for radial or combined loads. This design is best suited to support axial (thrust) loads in both (reversing) directions.

Thin section bearings are A-type, C-type, or X-type products. These lettered designations correspond to the contact styles described above.

• A-type products are angular contact bearings.
• C-type products are radial contact bearings.
• X-type bearings are four-point contact bearings.

No. Some are high precision and others are low precision. The ABEC scale defines bearing tolerances and consists of numeric and alphanumeric classes. Because these classes range from largest to smallest tolerances, ABEC 1F thin section bearings have less precision than ABEC 7 thin section bearings. 

Choose a bearing manufacturer who understands the importance of proper heat treating and quenching for thin section bearings. When a ring is heated, the manufacturer must hold it at temperature for a certain amount of time. The ring is then quenched, or rapidly cooled. This can put stress on the part and make the ring out-of-round or out-of-flat.