Thin Section Ball Bearing

Manufacturer of standard and custom thin section ball bearings to save weight, create space & reduce friction. Features include precision grades, corrosion resistance & internal fit up choices.

A special designed duplex pair of angular contact RBC Thin Section ball bearings was used in an airborne radar system. This application required combined load capabilities, low temperature compatibility and vacuum operation.

Types

Depending on your application, the type of thin section ball bearing you need will vary. For example, Silverthin’s radial contact thin section ball bearings are suited for radial loading. However, Carter notes that these bearings are not well suited for applications that require the support of moment or reversing axial loads.

These types of bearings also have a wide range of configurations such as four-point, angular contact and full complement. Additionally, they have different separator options, internal fit up choices, lubricants and corrosion resistance choices.

In addition, the diameters of these bearings can be very large. This means that they must be carefully inspected and measured before installation to account for their inherent out-of-roundness. This can be accomplished by using special gages that measure multiple points around the diameter. This process ensures that the bearing is positioned correctly in the application. This reduces the risk of premature failure and maximizes operating speeds. This can be especially important in high-speed applications like aerospace engineering, automation and extreme special environments.

Materials

Thin section bearings are incredibly compact and light, yet they are capable of carrying an impressive amount of load. This is largely due to their self-aligning design, which evenly distributes the load across many balls and allows them to tolerate a small degree of angular misalignment.

The range of materials available for thin section ball bearings varies greatly, with 52100 vacuum-gassed Chrome steel and 440C martensitic stainless steel common choices. They are also available in a range of specialist finishes such as black oxide, nickel and silver.

With such a wide selection of options available, selecting the correct thin section bearing for your application requires careful consideration. It is important to know the speed ratings that can be achieved, as these may be impacted by shaft and housing roundness, loading, lubrication and ambient temperature. Other key factors include separator options, cross-sections, internal fit up options, radial play and corrosion resistance options. Carter Manufacturing Limited, the European Master Distributor for Silverthin, is able to provide guidance on selecting the most suitable solution for your application requirements with accuracy, optimal value and performance in mind.

Design

For many applications it is important that the dimensions of thin section bearings are carefully designed to fit into the space available. The ABMA design standards for these bearings (see Tolerance Tables) specify a range of tolerances for the diameters and the overall length of the inner and outer rings. These will impact on the running accuracy and radial play of the bearings.

In addition to selecting the correct precision grade, designers will also need to consider ball type selection, angular contact or four-point angular contact options and cage designs. Alternative materials options and lubrication choices are also possible for some bearing sizes.

Lastly, the speed ratings for thin section bearings must be taken into account in any application as they are based on static and dynamic loads and radial or axial loading. The k values shown give an indicative guide for the maximum speeds at which these bearings can operate but will be impacted by load conditions, ambient temperature and lubrication.

Applications

Thin section ball bearings are used in critical applications and environments where space is limited, precision is vital, and weight must be minimized. They are an effective alternative to standard bearing sizes and can reduce total system cost.

An aerospace instrument gimbal assembly required a bearing that would take combined radial, axial and moment loads while maintaining low running torque. This was achieved using a special duplex pair of angular contact RBC Thin Section Ball Bearings with a light preload.

RBC thin section bearings are available with brass, nylon and phenolic cages. Cage design and material can significantly impact bearing speed ratings. The X-type, with gothic arch raceways and four contact points between the balls and races, is ideal for moment loading. Other variables that affect speed ratings include load conditions, lubrication and shaft roundness.