Benefits of Thin Section Bearings

Kaydon Rodriguez manufactures thin section bearings that work well in a wide variety of applications, from airborne optical and infrared scanning equipment to camera gimbals. These lightweight bearing types have small cross sections that stay the same as bore sizes increase, allowing for reduced space requirements and lower system weight.

Radial Load Capacity

A thin section bearing has a high static radial load capacity. They are typically used for a majority of applications that require a large number of radial loads. These bearings can also support moderate axial loads in combination with radial loads, although they are designed for primarily radial loading.

The dynamic radial load rating of a thin section bearing is dependent on the lubrication, seal selection and the internal fit up of the bearing. A standard bearing will typically have a radial play of 6-12 per cent of its dynamic load rating, which is acceptable for most radial loading applications.

Some manufacturers offer a duplex pair of angular contact thin section bearings that can accommodate both radial and a single direction of a thrust load. This type of bearing is commonly used in applications such as airborne turret azimuth drives. To maintain low torque while accommodating multiple loads, these angular contact bearings have special toroidal separators and stainless steel rings.

Thrust Load Capacity

As they are smaller and lighter than standard bearings thin section bearings offer significant weight savings. When designing a new machine, particularly when space and weight are critical considerations, this is a major benefit.

Similarly, when an application is expected to generate moment loads this is another area where the thin section bearing can excel. These type of bearings have an inherent resistance to moment loading that is not available in standard bearings.

Thin section ball, roller and tapered bearings are typically manufactured in chrome steel and have a maximum operating temperature of 120degC constant or 150degC intermittent. When combined radial and thrust loads are encountered a duplex pair of angular contact thin section bearings can be used to support the load with one bearing taking the axial load and the other bearing supporting the radial load. This is often referred to as the ‘A-Type’ configuration. Alternatively an X-Type bearing can be used in conjunction with a float C-type bearing to accommodate heavy axial and radial loads simultaneously.

Axial Load Capacity

With a very small cross-section relative to their diameters, thin section bearings can support axial loads in addition to the radial load they are designed for. This allows them to achieve good rigidity and running accuracy with relatively low mass, as well as compact designs.

However, the amount of axial load a thin section bearing can take is limited by the difference between the inner and outer ring diameters. This is referred to as the axial clearance and is defined by the dimensional specification of the bearing.

Some thin section bearings are available as matched pairs, which can allow the bearing to support axial loads in both directions. This design offers higher loads and lower torque than a single bearing solution. Unwanted moment loads can also be combated by the use of a preload, which establishes an optimal synergy between the rolling elements and the raceways. By taking these factors into account, designers can make sure they get the maximum performance from their axially loaded thin section bearings.

Combination Load Capacity

The thin section design of a bearing reduces its weight. Depending on the application, this can result in significant weight saving.

It can also allow for smaller design envelopes and reduced mass. This can lead to improved rigidity and running accuracy.

In addition to their low weight and compactness, many of these types can also be specified with specialist coatings that increase Rockwell hardness and provide anti-corrosion performance. This can further improve the service life and performance of a component.

With careful design, these bearings can be used in a wide range of applications. Engineers should always consider critical speed, load and temperature data when choosing a suitable bearing type and size for an application. They should also ensure that the shaft and housing roundness is acceptable. This is particularly important as thin-section bearings can be significantly distorted by poor shaft or housing roundness. The correct mounting arrangement will also reduce the radial play and noise caused by the interference fit between the inner and outer rings.