spherical bearings
Spherical Bearings
A spherical bearing is a bearing that permits angular rotation about a central point in two orthogonal directions (usually within a specified angular limit based on the bearing geometry). Typically these bearings support a rotating shaft in the [bore] of the inner ring that must move not only rotationally, but also at an angle.
Spherical bearings can be of a hydrostatic or mechanical construction. A spherical bearing by itself consists of an outer ring and an inner ring and a locking feature that makes the inner ring captive within the outer ring in the axial direction only. The outer surface of the inner ring and the inner surface of the outer ring are spherical (or more correctly, toroidal) and are collectively considered the raceway and they slide against each other, either with a lubricant, a maintenance-free (typically polytetrafluoroethylene or PTFE) based liner, or they incorporate a rolling element such as a race of ball-bearings, allowing lower friction.
Spherical Plain Bearings (also known as “Spherical Plane Bearings” "Spherical Ball Bushing Bearings" and “Ball Bushings”) have an inner ring with a sphere convex outside surface and an outer ring with a correspondingly sphere, but concave inside surface. Their design makes them particularly suitable for bearing arrangements where alignment movements between shaft and housing have to accommodate, or where oscillating or recurrent tilting movements must be permitted at relatively slow sliding speeds.
Spherical Plain Bearings are manufactured in a wide variety of materials and are designed to offer bearing solutions in almost any operating environment. AST Bearings offers a complete line of Spherical Plain Bearings available in inch and metric. These High-Quality Spherical Plain Bearings are suitable for heavy-duty, off-highway vehicles, agricultural equipment, construction and mining and logging equipment, packaging and textile equipment, and robotics. The plain bearings come in standard industrial bore sizes from 0.5" to 12" inches, as well as metric sizes from as small as 4 to 300 mm. Custom sizes can also be ordered.
In spherical roller thrust bearings the load is transmitted from one raceway to the other at an angle to the bearing axis. The bearings are therefore suitable to accommodate radial loads in addition to simultaneously acting axial loads. Another important characteristic of spherical roller thrust bearings is their self-aligning capability. This makes the bearings insensitive to shaft deflection and misalignment of the shaft relative to the housing.
SKF spherical roller thrust bearings incorporate a large number of asymmetrical rollers and have specially designed raceways with an optimum conformity. They can therefore support very heavy axial loads and permit relatively high speed operation.
SKF spherical roller thrust bearings are produced in two designs depending on the size and series. Bearings up to and including size 68 identified by the designation suffix E have a pressed steel window-type cage which, with the rollers, forms a non-separable assembly with the shaft washer. All other bearings have a machined brass or steel cage which is guided by a sleeve held in the shaft washer bore. The shaft washer and cage with rollers form a non-separable unit.
