Self Aligning Thrust Bearing

Self aligning thrust bearing are compact rolling element bearings that allow for a degree of shaft misalignment and generate less frictional heat than other types of bearings. They consist of an outer ring, an inner ring with two raceways and a cage that holds the rolling elements.

They have an outstanding load carrying capacity for radial and thrust loads in one direction. They also accommodate a significant amount of shaft deflection.

Self-alignment

Self-aligning thrust bearings can counteract both static and dynamic misalignment between shaft and housing. They can also tolerate angular misalignment of up to 3 degrees. They can handle both radial and axial loads but have lower axial load capacities than angular contact bearings.

This is because the spherical raceway of the outer ring has a center of curvature that matches the inner ring and cage, which allows them to rotate freely around the bearing’s axis while maintaining alignment. This design makes self aligning ball bearings insensitive to angular misalignment and shaft deflection, which increases their overall performance.

They can also withstand high-speed operations without much heat generation, compared to other types of ball bearings. This reduces maintenance costs and extends their service life. In addition, they operate faster than other bearings, which is crucial for some applications. They’re often sealed to prevent dirt from contaminating the rolling elements, which helps them to run cooler and increase their lifespan.

Lubrication

A self aligning thrust bearing is a type of roller or spherical bearing that handles axial loads on a vertical shaft. They can be either TT or TTF type, with a flange on the housing washer (outer ring) or without one.

A spherical mating surface 19, 21 on the thrust block and a convex surface 24 on the thrust collar provide means for adjusting the alignment of the runner bearing surface normal to the geometrical axis of the shaft and for centering the shaft. A bolt 40 extending through the apertured plate 39 may engage a tapped hole 41 in the collar and, when tightened, the collar is pivoted on the shaft toward the spherical surface of the thrust block.

The three most common causes of bearing failure are contaminants, misalignment and overloading. Avoid contamination by maintaining a clean work environment, using proper tools and cleaning and inspecting equipment regularly. Also, ensure that the bearings are properly lubricated and use high-grade lock nuts to prevent damage to threads or shaft seats.

Seals

Self aligning thrust bearings can tolerate large axial loads and operate at speeds between moderate and high. In addition, they can accommodate a slight amount of misalignment because their raceway is inclined to the shaft’s axis.

However, these types of bearings can experience heavy, shifting McPherson strut loads that compress their components and tend to misalign them. That’s why rigorous sealing is important.

The barbed lower edges of the sealing flanges contact the sloped seal surfaces to create, in effect, inner and outer grease reservoirs 46 and 48 that wet lubricant down to reduce wear. These flanges also provide a tortuous surface that prevents abrasive particles from entering the contact area.

NEWORLD self aligning thrust bearings in face-to-face and back-to-back arrangements can be designed to have small axial clearance (see diagram 1). This allows the bearing arrangement to operate without an external preload, which is often cost-effective. Contact NEWORLD for application engineering services. Typical applications include service pumps, extruders and sludge/water separation presses.

Design

Self aligning ball bearings are designed to tolerate large amounts of shaft deflection and misalignment. They can also withstand moderate axial loads. The radial load capacity is less than that of a deep groove ball bearing due to the larger outer raceway radii which reduces the amount of ball to track contact.

These bearings feature inner ring raceways that are similar to double row deep groove ball bearings and an outer ring with a spherical raceway. The center of the spherical curvature matches with the bearing center, which makes them internally self aligning. Permissible angular misalignment, depending on the dimensional series, is typically 2 to 4 degrees under normal load.

Spherical roller thrust bearings accommodate heavy axial and simultaneous radial loads. They can operate at high speeds with low friction and require little maintenance. They are ideal for injection pump governor linkage axial thrust loads, steering boxes and auxiliary vehicle equipment. They can only withstand axial loads acting parallel to the shaft and can not tolerate significant shaft misalignment.