Slewing bearing safety instructions

The slewing bearing is a large-sized bearing with a special structure capable of simultaneously supporting a large axial load, a radial load, and an overturning moment, and a combination of functions such as support, rotation, transmission, and fixation.

A, installation plane

The installation surface should be smooth and clean. Remove any excess material such as paint residue, beads, burrs, etc. Be careful not to let the solvent penetrate the inside of the slewing bearing while cleaning. Do not use solvents that damage the sealing material. The mounting surface should be dry and free of lubricant before assembly. Measures should be taken to protect workers and the environment.

The roughness of the mounting surface of the mounting bracket is not greater than Ra=12.5, 6.3μm. The flatness error of the mounting surface must detect the circumferential error and radial error. The circumferential flatness tolerance value has a corresponding standard value range depending on the diameter of the raceway bearing raceway.

In order to avoid local unevenness of the mounting plane or local overload of the slewing bearing due to bearing deformation, the circumferential flatness error can only have one wave undulation in any 180 degree range, and the change is gentle.

B, the stiffness of the bearing

Standard slewing bearings and zero-gear slewing bearings have different requirements for the rigidity of the bearings.

C. The inner and outer ring raceways of the positioning slewing bearing have a soft band and should be placed on both sides of the main load plane. That is, it is offset 90 degrees from the main load area. There is a blockage or "S" mark at the soft band.

In addition, check the match between the bearing of the turntable and the mounting surface. The feeler check is usually used. If the fit is not good, it should be filled with proper materials. After the slewing bearing is installed, it is forbidden to perform welding work on the bearing.

D, strong bolts

1. Selection of mounting bolts: Mounting bolts and washers should be used (size, quantity, strength grade, etc.). Also note:

1) Fully threaded bolts cannot be used

2) Do not use old bolts and washers

3) Do not use open washers such as elastic washers, etc.

2. Selection of bolt pre-tightening torque: The pre-tightening force of common metric bolts is recommended to be 0.6-0.7 times the bolt yield strength. It is recommended to use hydraulic fastening devices for bolts larger than M27. The preload should not exceed 85% of the yield strength.

3, fastening bolts: Slewing bearings should be installed under no load conditions. note:

Apply a bit of oil on the threads of the bolt to ensure a uniform balance of friction. Do not use glue on the bolt loose pieces.

Pre-tightening bolts: It should be pre-tightened in three steps. The three-step forces are 30%, 80% and 100% respectively.

E. Adjust gear backlash

When installing a toothed slewing bearing, it is important to correctly adjust the gear backlash. The feeler can be adjusted with a feeler gauge at the highest point of the radial runout of the gear, or it can be made of pressed wire or other suitable method. If the backlash is not within the specified value, the movable pinion changes the center distance. After setting, turn the slewing bearing at least one full turn to confirm that there is no other tooth high point, and check the backlash clearance after the slewing bearing is finally fixed. The highest point of the radial runout of the gear is marked with green paint in the tooth gap.

F, first lubrication

1, roller lubrication

In order to ensure adequate lubrication, grease should be refilled prior to initial use on the drawings or product instructions. Pay particular attention to all the grease nipples, one by one. It is best to turn the slewing bearing while pouring oil until you see the grease extruding.

2, gear lubrication

When the gears are lubricated, the tooth surfaces should be clean. It is recommended to use a clean brush to brush the grease on the gear.