Bearing Directory » Slewing Bearing

To "slew" means to turn without change of place; a "slewing" bearing is a rotational rolling-element 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.

Compared to other rolling-element bearings, slewing bearings are thin 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.

The single-row four point contact ball slewing ring 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.
It may be used for slewing conveyers,welding arm and positioner,light,medium duty cranes,excavators and other engineering machines.

The double-row Ball slewing beraring has three seat-rings.The steel balls and the spacers may be directly arranged into the upper and lower races.Two rows of steel balls with different diameters are fitted according to the force bom.
Such open mode fitting features extraordinary convenience.The load angles of both upper and lower races are 90°,which enable the bearing to bear large axial force and the tipping moment.
When the radial force is larger than 1/10 of the axail force the races should be newly designed.
As the axle and the dimension of the double-row ball slewing bearing are rather large,the bearing construction is sturdy ,hence it is especially suitable for tower cranes which require working radius over medium range,mobile cranes and loading and unloading machines.

Three-row roller slewing bearing has three seat-rings,which separate the upper,lower and radial races,via which the load of each row of the rollers may be specified.It may bear different loads simultaneously and its load capacity is the largest one among the four models.
Thanks to the large size of its axle and radius,it is sturdy and especially suitable for hearvy-duty machines which require large working radius.such as bucket-wheel excavators,wheeled cranes,ship cranes,ladle turret,heavyduty mobile cranes etc.

The single-row crossed roller slewing ring is composed of two seat-rings.It features compact in design,light in weight,high precision and small fitting clearance.
As the rollers are 1:1cross aranged,it is suitable for high precision mounting and capable to bear axial force,rsultant moment and considerable large radial force.
The single-row crossed roller slewing rings are widely used for hoisting,transporting,engineering machines as well as for military products.

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Articles

Causes of slewing bearing damage and countermeasures to improve

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Slewing Bearing Construction Machinery stomatal or dissection as a result of material on, roll-Road Tour hardened layer hardness, the depth of non-uniform, such as manufacturing quality problems or the reasons for some of the outside world, resulting in hardened layer Raceway off or broken tooth ring gear, equipment will not work properly.