Heavy Duty Heavy Duty Ball Slewing Bearing for Excavator

Heavy Duty Ball Slewing Bearing for Excavator

LYXQL can produce many different constructers of slewing ring bearings, including single row ball slewing bearings (also called four point contact ball slewing bearings), double row ball slewing bearings (including same ball diameter double row ball slewing bearings and different ball diameter double row ball slewing bearings), crossed roller slewing bearings, three row roller slewing bearings and ball and roller combined slewing bearings.

Maintenance method for slewing bearing of excavator

Hydraulic excavator generally consists of single-row four-point contact ball internal gear slewing bearing. The maintenance of excavator slewing bearing mainly includes the lubrication and cleaning of raceway and internal gear ring, the maintenance of internal and external oil seals, and the maintenance of fastening bolts.

1. Raceway lubrication

The raceway cavity is generally lubricated with 2 # lithium-based grease, and the greasing cycle is generally 100h. Under special conditions such as dust, high temperature and continuous operation, the filling period should be appropriately increased. When adding grease, it is necessary to rotate the slewing bearing and add °~25 ° every 15 minutes. When filling, pay attention to observe the outer sealing ring of the slewing bearing. Stop filling when you see the grease leaking from the outer sealing ring for one circle.

2. Maintenance of gear flexible area

If you put the rubber pad under the metal cover, fix it with bolts. If the bolts are loose or the rubber pad fails, water will leak from the metal cover into the lubricating cavity (oil pan) of the rotating gear ring, resulting in premature failure of the lubricating grease, reduced lubrication effect, and increased gear wear and corrosion.

3. Maintenance of inner and outer oil seals

The inner and outer oil seals of the slewing bearing are of rubber sealing strip structure and bear less pressure. The outer oil seal is located on the lower surface of the inner gear ring of the slewing bearing to prevent foreign matters such as external sand particles from the slewing bearing from entering the raceway and causing wear of the rolling body and raceway; The inner oil seal is located on the upper surface of the outer ring of the rotary bearing to prevent the grease in the lubricating cavity of the inner gear ring from entering the raceway cavity.

4. Maintenance of fastening bolts

When the slewing bearing bolts are tightened, the force shall not be exceeded. When the tensile force of the bolt exceeds the tensile strength of the bolt itself, the preload will not be formed. In order to ensure the reliability of bolt work, 10.9 strength bolts shall be replaced according to this type of bolts. The material shall be 45 # steel, and the hardness shall be HRC39 flat washer after medium temperature quenching and tempering. The use of spring washer is prohibited.

5. Adjustment of gear clearance

When the slewing ring gear is assembled with the output gear of the slewing motor reducer, the gear backlash should be adjusted at the high point of the radial runout of the inner tooth pitch circle of the slewing ring. At the maximum radial runout point of the inner pitch circle of the slewing bearing of the excavator, the backlash Sh of the reducer gear of the rotating motor is ≥ 0.03m (m is the gear modulus).

Generally, after the excavator rotates, its slewing bearing is prone to noise, impact and other failures. Operators should pay attention to observation, timely inspection and troubleshooting. Only by properly and reasonably maintaining the slewing bearing can it ensure its normal operation, give full play to its performance and extend its service life.