Slewing bearing

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.

As for other bearings that reciprocate, rather than rotating continuously, lubrication can be difficult. The oil wedge built up in a continuously rotating bearing is disrupted by the stop start motion of slewing. Instead, a hydrostatic bearing with pumped oil flow may be used.

Double row ball slewing bearing, slewing ring has three seat rings, the steel ball and spacers can be directly arranged into the upper and lower race, and the steel ball has two different size.

Double row different ball slewing bearing , slewing ring’s axial and radial loads are relatively large, it is specially suitable for the medium diameter tower cranes, truck mounted cranes etc.

Model Pdf.format	Dimensions ( mm)							Mounting dimension (mm)
	Da	O	U	Di	Ha	Hb	H	La	na	da	Li	ni	di
WD-073.22.0916.pdf	1010	822	918	786	80	88	98	974	36	18	858	36	18
WD-073.25.1105.pdf	1202	1008	1115	962	88	98	110	1166	36	18	1044	36	18
WD-073.30.1220.pdf	1332	1108	1222	1062	98	110	120	1290	48	22	1150	48	22
WD-073.30.1593.pdf	1713	1473	1595	1418.4	98	110	120	1667	48	26	1519	48	26