Steel-on-Steel Double Fracture
Spherical Plain Bearings requiring maintenance (steel-on-steel) have hardened sliding contact surfaces on both rings. The surfaces are typically treated with molybdenum disulphide and phosphate. It provides added wear resistance and wear-corrosion. However, Spherical Plain Bearings with this sliding contact surface combination require regular relubrication. The high strength of the sliding contact surfaces makes these bearings especially suitable for bearing arrangements where heavy loads of alternating direction, shock loads, or heavy static loads have to be accommodated.
When Spherical Plain Bearings reach a certain size, during assembly at the factory, the outer rings may go beyond their ability to return to their intended size and shape as the stress exceeds their yield strength during the insertion of the inner ring. To accommodate larger size spherical plain bearings, factories have created a “double fracture” method of forging and assembling the bearings. In this case, a double fractured outer ring consists of two segments of approximately equal size and a means of holding the bearing assembly together such as a snap ring or other form of tie such as a plastic or metal strap. After pressing the bearing into a housing bore, the fractured surfaces of the two outer ring halves interlock making the fracture line barely detectable.
AST’s double fractured, spherical plain bearings go up to a 460 mm bore and a dynamic load rating of up to 9,000,000 Newtons (Cr) and are subdivided into the following series:
- GE-XS/K Series – Steel-on-Steel, Metric Dimension, with extended inner rings
- GEC-XS Series – Steel-on-Steel, Metric Dimension, with lubrication groves, large size
- GEC-XS-2RS Series – Steel-on-Steel, Metric Dimension, with lubrication groves, large size, with Seals
- GEK -XS-2RS Series – Steel-on-Steel, Metric Dimension, with lubrication groves, with Seals, for high misalignment
If you need help in selecting the best products for your particular application, please remember that design engineering and application assistance are available from AST as part of our value-added services designed to make your job easier.
Click here to go to our online catalog and product specifier Double Fracture Spherical Plain Bearings including free CAD downloads.