Four-point Contact Ball Transfer Bearing

The four-point contact ball rotary bearing is a highly integrated compact bearing unit specifically developed for heavy-load and precision rotation scenarios. Its core innovation lies in the unique structural design of "forming four effective contact points between the inner ring, outer ring raceways and balls" - the balls and the raceways of the inner and outer rings respectively form symmetrical contact points on both axial sides, breaking through the bearing capacity limitations of traditional single bearings and achieving the composite function of "simultaneously bearing bidirectional axial load, radial load and overturning moment" by this structure, without relying on the multi-component combination scheme of "deep groove ball bearings + thrust ball bearings + supporting bearings".

The design intention of this bearing is to precisely address the three core pain points in fields such as construction machinery, automation equipment, and new energy equipment: Firstly, the need for high-precision rotation, such as the worktable of CNC lathes and robot rotating platforms requiring P5 level or higher rotation accuracy, to avoid processing errors or positioning deviations caused by insufficient bearing accuracy; Secondly, the need for large-load composite support, such as the slewing bearings of tower cranes and the rotating discs of port cranes needing to simultaneously bear the equipment's own weight (axial load), operational impact (radial load), and overturning moment caused by center of gravity offset; Traditional single bearings cannot meet the multi-directional bearing requirements; Thirdly, the need for compact space, such as the arm joint of concrete pump trucks and the installation space of small wind power yaw systems being limited, multi-bearing combination schemes are prone to be restricted by space and difficult to integrate.

With the integrated advantage of "replacing multiple sets with a single set", this bearing can compress the installation space of the equipment's rotating components by more than 40%, reduce the overall weight by 30%, and reduce the assembly processes by 50%, significantly improving the equipment's structural integration and assembly efficiency. From the market positioning perspective, it focuses on the mid-to-high-end heavy-load precision rotation support field, differentiating itself from ordinary rotary bearings (with precision mostly at P6/P7 level and limited bearing capacity), and also from the extremely heavy large roller rotary bearings (with bulky structures and difficult-to-satisfy precision requirements for precise scenarios), being a core product in the segmented market that combines "heavy-load bearing, precision rotation, and compact integration", widely suitable for mid-to-high-end equipment with high requirements for performance and space.

Based on the characteristics of the four-point contact ball turntable bearing, which are "heavy load + precision + resistance to harsh environments", it is widely used in scenarios requiring high-precision rotation and large-load support. The specific adaptation logic is as follows:
In the construction machinery field: The slewing bearing of tower cranes needs to bear the self-weight of the tower (axial load ≤ 200kN), the radial impact caused by the lifted load (≤ 80kN), and the overturning moment (≤ 60kN·m). The four-point contact structure of this bearing can stably withstand the combined load, and the IP65 protection can cope with outdoor rain, dust, etc. For crawler excavators, the upper vehicle body turntable needs to rotate at a low speed (≤ 8r/min) and with high stability. The P5 level precision of the bearing can reduce the rotation platform's wobble (wobble amount ≤ 0.02mm), improving the operation accuracy; for concrete pump trucks, the arm rotation joint space is narrow, and the "single set replacement of multiple bearings" compact design (installation space reduced by 40%) can adapt to the limited installation space of the joint.
In the automation and machine tool field: The worktable slewing bearing of the CNC vertical lathe needs to have high-frequency start-stop (start-stop frequency ≥ 10 times/hour) and high-precision indexing (indexing error ≤ 5″). The low friction coefficient (≤ 0.0015) and high rotational accuracy of the bearing can ensure the start-stop response speed and indexing accuracy; the seventh-axis rotating platform of industrial robots needs to bear the robot's self-weight (axial load ≤ 50kN) and the end load (radial load ≤ 20kN), and achieve ±90° precise rotation. The four-point contact structure of the bearing can balance the bidirectional load and avoid platform tilting; high-precision indexing plates need to maintain rotational accuracy for a long time (annual accuracy attenuation ≤ 0.001mm), and the precision processing of the raceway and stable lubrication system of the bearing can meet the long-term high-precision operation requirements.
In the new energy equipment field: The yaw bearing of small wind power equipment needs to operate in outdoor -30℃~80℃ environments, bearing the self-weight of the wind turbine cabin (axial load ≤ 150kN) and the overturning moment caused by wind force (≤ 40kN·m). The low-temperature adaptability (start torque ≤ 50N·m) and IP65 protection of the bearing can cope with the harsh outdoor climate; the turntable of the photovoltaic tracking system needs to frequently adjust angles (daily adjustment ≥ 20 times), and the low wear characteristics (wear rate ≤ 0.0005mm / thousand hours) and solid lubrication options of the bearing can reduce maintenance frequency (maintenance cycle extended to 1 year), and lower operation and maintenance costs.
In the heavy equipment field: The rotating platform of port cranes needs to bear the weight of containers (axial load ≤ 300kN) and horizontal wind force (radial load ≤ 100kN). The high load-bearing capacity (radial load ≤ 150kN) and impact resistance (impact strength ≥ 1800MPa) of the bearing can cope with the impact load of busy port operations; the rotating frame of the continuous casting machine of metallurgical equipment needs to operate in a high-temperature (≤ 150℃) and dusty environment, and the high-temperature adaptability seal (fluorine rubber sealing ring) and phosphating anti-rust treatment of the bearing can resist high-temperature dust erosion, ensuring the continuous operation of continuous casting.

 Summary of Product Core Advantages
High carrying efficiency: The four-point contact structure enables "a single set of bearings to bear multiple loads", replacing the traditional multi-bearing combination scheme. The installation space is reduced by over 40%, the equipment weight is decreased by 30%, and it can bear bidirectional axial (≤500kN), radial (≤150kN) loads and overturning moment (≤100kN·m), suitable for heavy-load combined working conditions.
High rotational accuracy: P5 level accuracy (radial runout ≤ 0.015mm, axial runout ≤ 0.01mm), the ultra-precision processing of raceways and balls ensures stable long-term operation accuracy (annual attenuation ≤ 0.001mm), meeting the positioning and rotation requirements of precision equipment such as machine tools and robots.
Strong environmental adaptability: IP65 protection level + phosphating anti-rust + temperature resistance -30℃~120℃ (ceramic ball models ≤ 200℃), capable of coping with harsh scenarios such as outdoor rain and wind, industrial dust, and high temperatures, with a failure rate of ≤0.3%/year, and a lifespan of over 15,000 hours (compared to 8,000 hours for ordinary rotating disk bearings).
Low maintenance cost:预留 convenient lubrication holes, some models support solid lubrication, maintenance cycle extended to over 1,000 hours; standardized structure and universal accessories, replacement of seals, balls, etc., does not require special tools, reducing operation and maintenance difficulty and cost (25% lower than imported bearings maintenance cost).

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