The Benefits of a Slim Ball Bearing

The small cross section of thin section ball bearings make them ideal for applications that require lightweight components. Kaydon offers a variety of slim bearing options to fit your system.

The Reali-Slim series of bearings have a uniform cross-section across all sizes, unlike standard rolling bearings where the cross section increases as the bore size increases. This allows for less mass and a smaller design envelope while maintaining high load capacities.

Optimal design

The design of a slim ball bearing requires attention to many details. A poorly designed bearing may suffer from reduced speed, load capacity and dimensional changes. The correct mounting of a bearing is also critical. Poor shaft or housing roundness can increase vibration and noise levels, or cause the inner and outer rings to distort during operation.

When designing with slim section ball bearings, consideration needs to be given to the radial play (diametral clearance). The bearing will need adequate radial preload to meet the required performance levels at both normal and high speeds.

Unwanted moment loads can be a design engineer's enemy, but they can be combated by using a thin-section bearing. These bearings have inherent resistance to moment loads, making them ideal for projects that have space and weight savings requirements. An optimal design methodology can be used to determine the bench bearing arrangement preload/clearance to maximize the bearing arrangement life. An optimization tool based on reliable but fast models can be used to achieve this.

Minimizing noise and vibration

The smaller cross section of a slim bearing makes it possible to fit more bearings into an assembly, decreasing weight and cost. It also means that vibration, noise and torque caused by each individual ball rattling within the cage and raceway can be greatly decreased.

To further reduce noise, vibration and torque, RBC offers a number of options such as seals and shields. A variety of ball and retainer types are available as well. The KA through KG and JU series of Reali-Slim bearings can be configured with one of four basic separator materials; brass, nylon, or phenolic. The RBC X and KAA series use a snap-over separator design.

RBC offers a wide selection of standard and custom designed thin section ball bearings to meet your low-speed application needs. Click on the INFO icons in the tables to see technical drawings and load and speed ratings. RBC Sales Engineers are available to discuss your specific application requirements.

Optimal lubrication

A key component of ball bearings is the lubricant used to reduce friction between the inner and outer rings. Without proper lubrication, the components can rub against each other, which generates heat and causes excessive wear. Lubrication can be provided by oil or grease, depending on the application.

For applications where relubrication is difficult or impossible, Kaydon’s line of slim thin section ball bearings offers an alternative solution. These bearings are ideal for robotics, inspection equipment and other light and medium duty applications.

A mathematical model was developed to study the relationship between lubricant viscosity and the vibration effect of full ceramic angular contact ball bearings. The results show that the temperature rise and the vibration acceleration level of the outer ring both decrease with increasing lubricant viscosity, reaching an optimal value at a viscosity of 32.0 mm2 s-1. The contact surface of the outer ring also shows no visible damage under this optimal viscosity.

Minimizing space

For applications that require minimal space, weight reduction and absolute precision such as medical equipment, satellite systems, optical and targeting equipment and robotics gimbals, the use of a slim ball bearing is essential. These types of bearings are also ideal for articulating arms found in automation machinery and robotic systems.

The radial contact bearings of Kaydon’s Reali-Slim line feature a constant cross section regardless of bore size, which helps system designers minimize their overall assembly costs and components by allowing them to standardize on one type of thin bearing for all loads. When heavier loads like reversing axial or moment loading are needed, Carter Manufacturing recommends using the X-type bearing which can withstand radial, reversing axial, and overturning moment loading.

Self-lubricating spherical plain bearings with inner and outer rings of maintenance-free sliding layers made of ELGOGLIDE or PTFE composite reduce or eliminate the need for regular lubrication, which can help to reduce maintenance requirements and system downtime. Other options such as four-point angular contact bearings, duplex pairs and cartridge bearing assemblies offer design flexibility for all load capacity, speed and accuracy requirements.