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.
Small Diameter Slewing Ring Bearing Rothe Erde with Internal Gear
To determine if a Slewing Ring bearing is appropriate for an application, a SERVICE FACTOR is applied. Refer to the table below for a guide to the service factor to apply to your application. The load rating curves shown in this catalog are approximate, and represent an application service factor of 1.00. To determine the required bearing rating, multiply the applicable service factor by the applied loads on the bearing, and compare the resultant loads to the load rating curves.
If you require any assistance in determining an applicable service factor, or would like a more detailed load rating curve (recommended if your service factor adjusted applied loads fall close to, or beyond, the load rating curves shown in this catalog), please contact Engineering for assistance. Please note that the equipment designer is responsible for determining the correct service factor, often validated by testing.
“Typical application” of Slewing Ring Bearings(http://www.slew-bearing.com/) will exhibit the conditions listed below. Special consideration must be given to bearing selection and features whenever the application conditions differ from those considered “typical”. Those typical application conditions are:
l Vertical axis of rotation. Essentially, the bearing mounted “flat”.
l Compressive thrust and moment loads being predominant compared to tension loading.
l Radial load limited to less than 10% of the thrust load.
l For single row bearings, intermittent rotation (not continuous) should not exceed a pitch-line velocity of 500 feet/minute.
l Operating temperature between -40ºF to +140ºF.
l Mounting surface geometry and installation procedures to assure roundness and flatness of both races. An example approach would be to apply a centered thrust load while tightening the bolts using the alternating star pattern method.
l Periodic checking of mounting bolts to verify proper tension is provided for.
l Periodic lubrication is provided for.
Slewing Ring Bearings(http://www.slew-bearing.com/aboutus.html) are designed to accommodate significant radial, thrust and moment loads as shown below:
This is accomplished in most cases by the unique four point contact raceway geometry, which is similar in concept to X-Type Thin Section bearings. This allows a single bearing to accommodate all three loading scenarios noted above, either individually or a combination thereof.
1. n1 is the nos of lubricating holes.Oil cup M10×1JB/T7940.1~JB/T7940.2.The Oil nipple's location can be change according to the user's application.
2. n-φcan change to tapped hole,the diameter of tapped hole is M,depth is 2M.
3. The tangential tooth force in the form is the max tooth force,the nominal tangential tooth force is 1/2 of the max one.
4. "K" is addendum reduction coefficient.