Thin Section Thrust Bearing

Thin section thrust bearing offer high load capacity and stability in applications with critical speed and temperature requirements. They also provide inherent resistance to moment loads.

A duplex pair of angular contact thin section ball bearings can be mounted to accommodate both radial and axial loads. This allows simpler mounting arrangements, especially when space and weight are important considerations.

Radial Load Ratings

The radial load ratings shown in the product tables indicate the static limiting load which causes permanent deformation of the bearing balls or raceway. They are calculated using a complex equation based on bearing geometry, number and size of ball, ring and raceway material and contact stresses at maximum theoretical contact load.

Static axial loads are determined in a similar manner and the axial load rating indicated is the minimum acceptable axial load for one million revolutions (rpm). This value is also used to calculate life ratings.

Silverthin thin section bearings are available in a wide range of sizes and types. This offers designers the opportunity to choose the most appropriate type and design of bearing for their application, including the choice of conventional C-Type radial contact with deep grooves for high radial load applications; or the alternative of angular or four-point contact which are better suited for support of moderate thrust and reversing axial loads. Other choices include a selection of cages, alternative materials and specialist lubrication such as vacuum-compatible oil or dry film lubricants.

Axial Load Ratings

With their smaller cross sections than standard bearings, thin section bearings help reduce overall system cost. This is especially important for applications where space and weight are major considerations, such as airborne optical/infrared scanning equipment and robotics.

Thin section bearings have an axial load rating of up to 30 percent of their static radial load ratings due to their shallower raceways. This is less than half that of full complement ball bearings, but still sufficient for most applications. Axial loads are best supported by using a duplex pair of angular contact RBC thin section bearings.

A duplex pair is ideal for heavy axial loads, allowing for differential expansion between the shaft and housing (caused by temperature differences) without adding axial stress to the bearings. However, they are not designed for moment or reversing axial loads. For those applications, an A-Type or X-Type bearing should be used. See the Load Ratings page for more information.

Thrust Load Ratings

Unlike radial ball bearings which locate the balls within the inner and outer rings, thrust bearings feature raceways machined on the faces of mating rings. This arrangement supports axial loads parallel to the shaft axis but does not support a significant radial load capacity. Carter Bearings offers several types of thin section thrust bearings to suit various applications and speeds. Click on INFO in the product tables to display technical drawings with critical speed, load and temperature data to assist in design and selection.

The basic static load rating Co, or "static capacity", is that contact stress at which permanent deformation of the ball and raceway occurs. This value is typically used to calculate theoretical life for the bearing.

Engineers can choose from a wide range of options to increase the performance of a thin section thrust bearing, including alternative cage designs, material options, and lubrication choices. In addition, preloading can be used to improve stability and provide higher accuracy in some applications.

Design Considerations

For projects that must cope with moment loads – including aircraft, automotive and marine applications - thin section bearings can deliver significant weight savings, when compared to standard options. This enables designers to achieve critical space and weight saving goals while maintaining required speed, load capacity and accuracy.

Split thin section bearings can be supplied with internal clearance or preload settings that are determined by the shaft and housing fit – thus eliminating the need for expensive special preloads to be requested at the design stage. This allows the design engineer to optimize the overall system by lowering component weight, reducing assembly costs and improving mounting precision.

Split thin section bearings are available with a variety of cage designs, alternative ball type choices and lubrication options. Typical elastomer molded seals are available, together with PTFE and 300SS molded designs or separable shields. For example, when low torque, multiple load capacities and corrosion resistance were key requirements for an airborne turret azimuth drive assembly, a duplex pair of RBC angular contact thin section bearings was specified with toroid separators. This solution reduced assembly weight by 7 lbs.