A slewing bearing or slew[ing] ring is a rotational rolling-element bearing or plain bearing that typically supports a heavy but slow-turning or slow-oscillating load, often a horizontal platform such as a conventional crane, a swing yarder, or the wind-facing platform of a horizontal-axis windmill. (To "slew" means to turn without change of place.)
Compared to other rolling-element bearings, slewing bearings are thin in section and are often made in diameters of a metre or more; the slewing bearings on the Falkirk Wheel are 4 metres diameter and fit over a 3.5 metre axle. Slewing bearings resemble oversize aircraft control surface bearings.
Slewing bearings often use two rows of rolling elements. They often use three race elements, such as an inner ring and two outer ring "halves" that clamp together axially.
Slewing bearings are often made with gear teeth integral with the inner or outer race, used to drive the platform relative to the base.
> > > Feature
Single Row Four Point Contact Ball Slewing Bearing is composed of 2 seat rings.It features compact in design,and light in weight.The balls contact with the circular race at four points,via which the axial force,radial force and resultant moment may be born simultaneously.
> > > Application
It can be used for slewing conveyor, welding manipulator, light & medium duty crane, excavator, and other construction machinery, welding arms and positioners, light,medium duty cranes,excavators and other engineering machines.