**Transport and storage
Large-diameter slewing rings,like any other machine part,require careful handling.They should always be transported and stored in the horizontal position;if they must be transported vertically,they will require internal cross bracing. Impact loads,particularly in a radial direction,must be avoided.
**Condition upon delivery (unless instructed otherwise):
Running system:Lubricated with a coating of one of the quality greases specified.
Gear:Non lubricated;treatment as for external surface
External surface:Tectyl 502C or equivalent.This material can be washed off with petroleum-based solvents.Care must be taken to prevent these solvents from entering the slewing ring.
**Preservation
Approximately 6 months in roofed storage areas.Approximately 12 months in enclosed,temperature-controlled areas. Extended storage periods will require special preservation.
**Installation:
The slewing ring support surface must be absolutely flat.The upper and lower must make perfect contact and this must be checked using a leveling instrument or a feeler gauge.The contact surface require machine.Welding beads,burrs,excessive paint residues and other irregularities must be removed.Non-machined contact surfaces can be provided with cast resin grouting,but only if use of grout was considered and approved by SOCARE at the design stage.
The protective coating should be removed from the upper and lower mounting surfaces of the slewing ring as well as from the gear.No solvent should be allowed to come into contact with the seals and raceways.Gears already greased should not be cleaned.
All grease nipples must be easily accessible. Where necessary,grease pipes should be provided to allow relubrication through all grease hole.
**Hardness Gap:
The unhardened zone between the beginning and the end of the hardened region of the raceway is identified by a stamped letter "S" near the nameplate or filler plug at the inner or outer diameter of each slewing ring ring.On a gear ring,the hardness gap is marked on the axial surface.On a point loaded ring,the hardness gap "S" should be positioned outside the main area of load.where possible.
**Gear:
At the point of maximum deviation of the pitch circle,three teeth are usually marked in green.This allows the satisfactory adjustment of the backlash.The backlash at the narrowest point should be at least 0.03/DP.After the final tightening of the bolts of the slewing ring the backlash should be checked around the entire circumference.
It must be verified that all the bolt holes in the slewing ring line up with the holes in the companion structure!Otherwise,the slewing ring may become distorted.
**Lubrication and maintenance:
The first relubrication of the raceway and the lubrication of the gear should be carried out immediately after installation.For this and subsequent lubrication,the lubricants in Table mentioned below,or their equivalent,are to be used.These raceway greases are lithium-saponified mineral oils of NLGI Grade 2 with EP additives.The raceway lubricants listed in Table can be mixed together.The lubricants are listed in random order and not according to quality.
The grease filling is there to reduce friction,seal the slewing ring and provide protection against corrosion.Therefore,the slewing ring must always be liberally greased so that a collar of fresh grease forms at the gaps and seals around the whole circumference of the slewing ring.Ideally ,the slewing ring should be rotated during relubrication.
**Lubrication Intervals:
Lubrication intervals are to be selected according to the operating conditions;generally every 100 operating hours,for ball slewing rings and every 50 hours for roller slewing rings.Shorter lubrication intervals must be used in tropical regions,in the presence of high humidity,dust or dirt,significant fluctuations in temperature,and where there is continuous rotation.
For automatic lubrication systems,a quantity of one gram of grease per fitting per hour is recommended for general applications.The grease maybe added hourly or at other scheduled intervals.
Before and after prolonged stoppage of the equipment,relubrication is absolutely necessary. This is especially important after a winter shutdown.When cleaning the equipment,care must be taken to prevent cleaning agents from damaging the seals or penetrating into the raceway.
