Slewing bearing, buy crane spare parts slewing bearing used for maintenance 011.45.1250.001 1390x1110x110mm on China Suppliers Mobile

Product Details

Slewing Bearings

Ø The slewing bearing is a basic mechanical component for engineering machinery, mining machinery, construction machinery and other machineries that require relative rotary motions of two parts. The slewing bearing serves to transmit movement, bears load, and connect. However, different from bearing applications, the slewing bearing is generally suitable for low speed and heavy load.

Ø The slewing bearing has a wide range of applications including engineering machinery, e.g. truck crane, excavator, and tower crane; mining machinery, e.g. bucket wheel machine; metallurgical industry, e.g. clay gun, ladle turret, furnace cover slewing mechanism, etc. It is also used for port machinery, welding machinery, wind power generating equipment, medical equipment, e.g. CT machine, etc.

Usage in Tower Crane

Usage in Truck Crane

Operation & Maintanence

Suitable lubrication is necessary for durability of raceway and gear. Lubricating grease improves capability and service life of slewing bearing, while working condition, e.g. load, temperature, speed, and vibration, determines lubricant selection.

Characteristics of recommended lubricant for slewing bearing:

² Lithium base grease

² Minimum viscosity of base oil: 150 mm2/S

² NLGI consistency grade: 2

² Anti-friction and extreme pressure additive

² Working temperature: -300 Ca+1200 C

² Four-ball test: Clinkering load STMD 2596 (NT24)>300

² Maximum NDM value (revolving speed x raceway center diameter)

ü For ball slewing bearing=60000

ü For pin roller slewing bearing=30000

Lubricating grease compatibility table

According to our experience, the lubricating greases listed in the following table are compatible with each other and with all parts of slewing bearing. Any other grease which is deemed compatible with any of the lubricating greases recommended by the Company is usable. However, molybdenum-containing disulphide M_OS₂is strictly prohibited.

Grease for raceway of slewing bearing		Lubricating grease designation			Grease for gear
	Aralub HLP2		ARAL	Aralub LFZ1
	Rhus L 474/2		MOTUL/bECHEM	Berulit GA 400
	Energrease LS-EP2		BP	EnergolwRL/GR 154 GS
	Grease LMX		CASTROL
	Epexa2/Epexelf2		ELF	Cardrexa DC1
	Beacon EP2		ESSO	Surret Fluid NX
	Mobilux EP2		MOBIL	Mobilgear OGL 007
	Retina EP2-Alvania EPLF2		SHELL	Malleus GL 205
	Multis EP2-Lical EP2		TOTAL FINA ELF	Ceran AD

This table is subject to update by manufacturer.

Removal of Common Faults

Difficult turning of slewing bearing

Every slewing bearing goes through strict inspection and test run before being released from plant, so all of them are acceptable products. As the slewing bearing has pre-tightening force on its sealing face and frictional force of the sealing face should be overcome for turning, it’s normal that certain starting moment is needed when it is turned.

In case of clamping stagnation in turning, the following method should be taken to remove the trouble:

Case	Cause analysis	Troubleshooting methods
Inflexible idling of new product	The slewing bearing has been stored for long time (e.g. over a half year) or the ambient temperature is low, which results in less liquidity of the grease inside, leading to inflexible operation. This case is prominent in cold regions and in winter.	After force is exerted, if it works well without any abnormal sound, it can serve for normal serve, but new grease should be filled until it is oozed from the seal. If operation is accompanied with any abnormal sound, check whether there is any damage caused during transport or storage and feedback the information to our after-sale service department for a solution.
Inflexible operation after installation	The mounting surface of the main machine does not match well with that of the slewing bearing, resulting in that after installation, axial clearance of the slewing bearing can’t compensate for deformation of the slewing bearing, raceway of the slewing bearing is distorted, and the roller moves with difficulty in raceway (sometimes with abnormal sound).	Rework mounting surface of the main machine to make it in compliance with the requirements; or treat the surface by filling in plastic or partial washer. If flatness is still unacceptable after completion of surface treatment, try to exchange for a slewing bearing with larger clearance.
	Bad gear engagement is caused by failure to adjust gear backlash according to radial top point of gear pitch circle (three teeth marked with green paint). Deformation is caused by compressing the slewing bearing at the top point, resulting in difficult turning or abnormal sound.	Adjust gear and pinion engagement and gear backlash again as required.
	Impurities are jammed in the gear and pinion.	Check and be sure that gear and pinion engagement is free of impurities.
Inflexible operation in use	The sealing strip is broken, resulting in entry of impurities into raceway.	Replace sealing strip or take effective sealing protection measures, e.g. installing guard plates.
	Failure to lubricate it with sufficient grease periodically according to the maintenance requirement, resulting in abnormal wear and tear of raceway.	Lubricate it with sufficient grease until grease is oozed out from the sealing strip. It’s noted that every oil cup should be oiled, and operation should be kept in oiling, if possible. If wear and tear is serious, the slewing bearing should be replaced. If you continue using it in short time, lubricate it with more amount of grease until grease overflows, so that the scrap iron is discharged as most as possible.
	Abnormal engagement between gear and pinion, with impurities or broken teeth	Remove impurities (if any); replace the slewing bearing, if there is any broken tooth.