The automotive wheel hub unit is mainly divided into the first generation, second generation, and third generation, which have significant differences in structure, integration, performance, and applicable scenarios, as follows:
1. The first generation wheel hub unit
Structural characteristics: It is composed of integral outer ring double row bearings, which are separated from the wheel hub and need to be connected by bolts. The optimal working clearance is pre-set before leaving the factory and does not need to be adjusted during installation.
Performance Features:
Sealing and Lubrication: Adopting a multi lip labyrinth sealing structure, one-time professional lubrication, effectively blocking impurities from entering, achieving lifelong maintenance free.
.Installation convenience: The structure is compact and easy to install, but it requires pressing the wheel hub and steering knuckle, and the assembly process is complex, requiring high equipment accuracy.
.Performance limitations: Due to the difficulty in precise control of installation processes, there are significant deviations in bearing performance, resulting in overall low performance.
.Applicable scenarios: Suitable for vehicle models that are cost sensitive and do not require high performance, such as some economy sedans and commercial vehicles.
.II. Second generation wheel hub unit
Structural features: Based on the first generation, the wheel hub flange is integrated, the bearing inner ring is integrated with the wheel hub, and the outer ring is independent.
. The outer ring is equipped with a flange, which can be directly connected to the suspension through bolts.Performance characteristics:
Integration improvement: reduces the number of assembly parts, reduces weight, and makes installation more convenient.
.Rigidity and reliability: The outer ring is integrated with the mounting flange, providing better rigidity and higher reliability.
.Performance optimization: The step of pressing the wheel hub is eliminated during assembly, but it still requires interference fit with the steering knuckle, with slightly higher assembly accuracy than the first generation.
.Applicable scenarios: Suitable for vehicle models that have certain requirements for installation accuracy and performance, such as some mid to high end sedans and SUVs.
.III. Third generation wheel hub unit
Structural features: highly integrated design, integrated wheel hub on the inner ring and flange connecting the steering knuckle on the outer ring.
. It usually includes 2-3 columns of rolling elements (balls or rollers), flanges, and sensors (such as ABS/ESP signal acquisition).Performance characteristics:
Integration and modularization: The bearings and wheels are integrated into one, greatly improving assembly accuracy. All dimensions are precisely controlled by the supplier, resulting in optimal performance.
.Rich functions: Integrated speed decoder or sensor, realizing real-time acquisition of speed signals, providing key data for vehicle control systems.
. NVH performance optimization: Modular design reduces radial runout, lowers noise and vibration, and enhances driving comfort.Applicable scenarios: Widely used in modern sedans, especially high-end models such as Mercedes Benz, BMW, Audi, etc.