Silverthin™ Slewing Ring Bearings
Silverthin™ Bearing Group, manufacturer of precision thin section bearings, has finally released it’s much anticipated slewing rings and pinions catalogue. A slewing bearing, commonly known as a turntable bearing, is typically a high capacity bearing used for significant axial and moment loads at minimal speeds. Slewing bearings are known for their compact design envelope and are therefore ideal for many heavy load applications with size restrictions. These slewing bearings are comprised of a four point contact ball bearings configured with “X-Type” races to account for these potentially large moment forces. Silverthin™ manufactures a range of sizes up to 72 inches outer diameter.
Figure 1: Silverthin™ slewing ring bearing shown with classic Silverthin™ thin section bearings
Both easy to mount and easy to maintain, the Silverthin™ Slewing Ring Bearings are able to be mounted via inner or outer ring with a range of mount hole types. They are also available ungeared, internally geared or externally geared to suit your application.
Figure 2: Silverthin™ externally geared and ungeared slewing ring bearings
Silverthin™ Slewing Ring Bearings are normally used in situations with slow, oscillating and/or intermittent rotation. There are many factors to consider when classifying an application as “typical” so be careful should yours differ.
Typical application conditions are:
- Vertical axis of rotation. Essentially, the bearing mounted “flat”.
- Compressive thrust and moment loads being predominant compared to tension loading.
- Radial load limited to less than 10% of the thrust load.
- For single row bearings, intermittent rotation (not continuous) should not exceed a pitch-line velocity of 500 feet/minute.
- Operating temperature between -40°F to +140°F (-40°C to +60°C)
- Mounting surface geometry and installation procedures to assure roundness and flatness of both races. An example approach would be to apply a centred thrust load while tightening bolts using the alternating star pattern method.
- Periodic checking of mounting bolts to verify proper tension is provided for.
- Periodic lubrication is provided for.
Figure 3: Slewing ring bearing application in a bottle carousel
Silverthin™ also offers a series of pinions designed to mate with their slewing ring bearings allowing easy integration with your drive train. These pinions are made in AISI 4140 steel and are hardened to have a surface hardness of 50-60 HRc.
Figure 4: Silverthin™ externally geared pinions
When selecting a Silverthin™ slewing bearing and pinion for your application you will need to know all of the data such as dimensions and load capacities. For all of this information please refer to the catalogue here or for technical and pricing assistance, contact Carter Manufacturing Limited here
Author: Erick Sloan, Carter Manufacturing Limited