How do you measure a slewing bearing?
Place the slewing bearing on the platform vertically, lift a slewing ring, Measure the clearance with the dead weight of the other slewing ring, Measure three point along the circumference of 120° and take the average . Other measurements are allowed.
What are slewing rings used for?
A slewing bearing or slew[ing] ring (also called a turntable bearing) is a rotational rolling-element bearing that typically supports a heavy but slow-turning or slowly-oscillating loads in combination (axial, radial and moment loads), often a horizontal platform such as a conventional crane, a swing yarder, or the …
How are slewing rings made?
Slewing ring bearings are comprised of two rings, each of which contains a precision raceway that is induction hardened on the surface to a specified depth. Each ring is made from a medium carbon steel forging.
What is a slewing gear?
A slew drive is a gearbox designed to handle radial or axial loads using high rotational torque. In addition, the slewing ring bearing, at the heart of the drive, enables it to withstand high overhung or moment loads. While turning, the worm gear’s axial movement transfers magnified torque force to the radial gear.
What is rocking test of Crane & how frequently you should perform it?
every six months
-‘Rocking tests’ are carried out every six months and that the results are recorded and monitored in order to ensure the wear tolerances remain within the limits. – The ship is adjusted to have least possible trim, preferably on even keel. – Bad weather / Windy situations are avoided.
How does a slew ring work?
A slewing ring, also known as a slewing bearing, is made up of an inner ring and an outer ring. One of which will generally incorporate a gear whilst both elements include attachment holes, enabling for optimised power transmission with a simple and fast connection between adjacent components.
Why do you slew a bearing?
Slewing bearings comprise an inner ring and an outer ring, one of which usually incorporates a gear. Together with attachment holes in both rings, they enable an optimized power transmission with a simple and quick connection between adjacent machine components.
How does a slew ring bearing work?
What is a slewing assembly?
Slewing bearing is a kind of large bearing with special structure, which can bear the overall load such as axial load, radial load and overturning load. It combines support, rotation, transmission, fixation, sealing, anticorrosion and other functions into one unit.
What is slewing in Crane?
Slewing is the rotation of an object around an axis, usually the z axis. An example is a radar scanning 360 degrees by slewing around the z axis. In crane terminology, slewing is the angular movement of a crane boom or crane jib in a horizontal plane.
When to use silverthin slewing ring bearings?
Silverthin™ Slewing Ring Bearings are used most commonly where rotation is slow, oscillating, and/or intermittent. For speed limit calculations please contact Silverthin Engineering. Silverthin™ Slewing Ring Bearings are not typically provided with diameter tolerances.
Is it worth remanufacturing a slewing bearing?
A slewing bearing with only 30% left of its calculated service life can be well worth remanufacturing. SKF’s standardized remanufacturing processes can extend significantly the service life of critical equipment. All of these combine to improve rotating equipment performance and reduce total cost of ownership.
What should the temperature be for slewing rings?
Silverthin™ Slewing Ring Bearings are often used indoors, and outdoors where exposure to moisture and significant contamination is possible. Normal temperature ranges -40°F to +140°F (-40°C to +60°C) are standard.
What kind of slewing bearings do SKF use?
SKF has extensive experience in designing and manufacturing customized or special slewing bearings, for example, slewing bearing with combined roller/ball bearing (as shown), with segmented bearing or with inserted raceways bearing. Depending on their design, slewing bearings have the following features: