how does a slewing bearing work

Nowadays, slewing bearings are widely used in a variety of applications such as cranes, forest industry, public works and so on. As a manufacture which produces high quality slewing rings, it’s important for us to make you have a better command of slewing bearings. In this article, we will introduce you about how a slewing ring bearing works.

A slewing ring is a contained system of balls or rollers, caging, raceways, mounting provisions, and often, integral gearing as well. According to the definition of Wikipedia, a slewing bearing or slewing 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. Under this condition, to "slew" means to turn without change of place.

Slewing bearings are typically used to drive the platform relative to the base. Usually, a slewing bearing ring uses two rows of rolling elements. Besides, three race elements, such as an inner ring and two outer ring "halves" that clamp together axially are also widely applied to a slewing ring. Gear teeth integral with the inner or outer race are often used to make a slewing bearing. Compared to other rolling-element bearings, slewing bearings are thin in section and are often made in diameters of a meter or more.

In lifting equipment, the large diameter bearing serves as a joint between the upper structure and the undercarriage, providing a means of 360-degree rotation. Typically, lifting devices have a complex load spectrum: the slewing ring bearing can simultaneously handle all combinations of thrust, radial, and tilting moment loading. There is another advantage of using a slewing ring bearing: its shiftless design eliminates the need for a spindle or kingpost. The center of the bearing remains open, which allows the passage of various hydraulic and control components.

These large units are designed to transmit axial, radial, and tilting moment loads. And because they handle loads (and different combinations of them) in one assembly, these bearings eliminate weight, space, and cost penalties of other rotational designs.

Slewing rings are characterized by a high rotating speed, constant rotating torque and low noise; it is the result of the precision of our finishing by grinding. Slewing bearings are very commonly used both indoors and outdoors. Even under extreme environments, slewing ring bearings can be applied with the best bearing system solution.