What is four point contact ball slewing bearing

The four point contact ball slewing bearing is mainly composed of inner ring, outer ring, single row steel balls, cage (or isolation block), sealing device and other components. The inner and outer rings of the four point contact ball slewing bearing have integral and split structures. The overall rigidity of the ferrule is relatively strong, and the split structure is easy to adjust. Before the product leaves the factory, the two split rings are connected together using bolts. Generally speaking, four point contact ball slewing bearings have cages (or isolation blocks), and only when the load is relatively large, a fully loaded ball structure is selected. The fully loaded ball type four point contact ball bearings have a large bearing capacity, but high frictional resistance, and friction can also easily cause scratches on the surface layer of the steel ball. The basic structure of the four point contact ball rotary table bearing/slewing support includes toothless, external tooth, and internal tooth types, with high static load capacity.

Features of four point contact ball slewing bearing

Single row four point contact slewing bearing, this type of bearing is composed of two steel rings, and the steel ball is in contact with the circular arc track at four points. It can withstand axial force, radial force, and overturning torque simultaneously. This type of bearing is characterized by compact structure, light weight, high accuracy, and strong bearing capacity.

The separated bearing structure is easy to install and adjust.

• It can withstand radial and axial bidirectional loads, has strong load-bearing capacity, and occupies relatively less bearing space.

• Small axial clearance and high limit speed.

• It is not suitable to bear loads mainly composed of radial forces.

• During the use of the four point contact ball rotary table bearing, it is necessary to regularly add lubricating grease. When adding lubricating grease, the bearing can be slowly rotated to make the lubricating grease fill evenly.
  

• Keep the four point contact ball bearing and working environment clean and regularly remove debris.

• After 100 hours of equipment operation, it is necessary to check and maintain sufficient bolt pre tightening force.

• Pay attention to the operation of the equipment at all times during use, and if there are any abnormalities such as noise, stop the machine for maintenance in a timely manner.

• The sealing ring needs to be checked frequently, and if it is damaged, it needs to be replaced in a timely manner.

Material of four point contact ball slewing bearing

Steel ring: material S48C, 42CrMo4, etc.

Steel ball: Material GCr4, GCr9, GCr15 SUJ2 and other bearing steels.

Isolation block: commonly used materials such as resins such as PA, PP, PE, etc. Reference data for isolation blocks: compression deformation, pressure resistance value, water content, etc.

Sealing strip: Generally, materials with good oil resistance are selected, such as NBR/PVC SAEJ200H, hardness: HS75, appearance requirements: flat and without deformation, installed on the inner and outer rings of the slewing bearing to isolate dust and protect internal grease. The sealing lip should be easily attached to the end face of the inner or outer rings of the slewing bearing, and good sealing performance is required.

Application of  four point contact ball slewing bearing

It is widely used in various fields such as construction machinery, such as excavators, pile drivers or cranes, military equipment, etc. It mainly transmits load and motion through point contact between the inner and outer wheels and the rolling body. Due to the large load transmission and small contact area, the stress concentration in the contact area is very obvious.