QUEENSLAND BEARINGS recently sold  this Slew Ring Bearing to Reef Master Boats and it is 934 mm inside and 1050 mm outside diameter.  These bearings are commonly used in cranes and are also used in scissor lifts, observatories and radar towers for example.

FITTING AND MAINTENANCE

The ball bearing turntable must be mounted on a completely flat and horizontally and vertically rigid base with at least 50% of the circumference adequately supported.  Particular attention should be paid to the support of the web section area containing the ball bearing races.  Any unevenness under the flanges can be corrected with metal strips or by filling in with plastic metal.

Each flange must be attached with a minimum of 8 high tensile bolts.  The thickness of paint between turntable and frame should not exceed 50 mm to guarantee the fit to be friction-tight.

To ease the shear load on the mounting bolts at least four blocks should be welded on immediately adjoining each flange.  The ball bearing turntable must no be mounted by means of welding.

JOST turntables are lubricated with a lubricant suitable for the type of operation and the adherent operating conditions before they leave the factory, however, the turntable must be adequately relubricated with high quality ball bearing grease (lithium saponified, NLGI class 2) before the trailer is put into operation for the first time. The re-lubrication should build up a collar of grease in the gap between the 2 rings of the turntable thus preventing ingress of grit and water into the ball races.

The ball bearing turntable must be lubricated according to use but at least once a month with a lubricant suitable for the type of operation and the adherent operating condition.

Ball bearing turntables are subject to wear. the limit of wear is reached when there is 2.5 mm axial play.  This is the case at the very latest when the air gap X=1 mm at any point on the circumference of the turntable.

We hope this information is helpful.

Linda Lang, Queensland Bearings & Industrial Supplies.