In automotive driving systems, wheel hub bearings are the "critical hub" connecting the wheels and suspension. They must bear the weight of the vehicle (radial load) while transmitting driving torque and braking loads (axial load), while maintaining stability and low noise at high speeds (up to 6000 rpm). From traditional split-body structures to integrated units, and from the conventional demands of fuel-powered vehicles to the high-torque and high-speed challenges of new energy vehicles, automotive wheel hub bearings have become core components for ensuring driving safety and enhancing the driving experience through continuous structural optimization and material innovation. This article will systematically analyze the material and process breakthroughs, vehicle adaptation solutions, fault diagnosis systems, and electrification trends of automotive wheel hub bearings based on the technical logic of structural evolution, revealing how they adapt to the upgraded needs of the automotive industry through technological innovation.

1. Structural Principles and Integrated Evolution: From "Split Assembly" to "Unitized Intelligence"

The core value of automotive wheel hub bearings lies in their triad of "load bearing + transmission + stability." Their structural evolution has consistently revolved around simplifying assembly, improving reliability, and integrating more functions. Three generations of technology have emerged, each corresponding to a leap forward in automotive manufacturing efficiency and performance.

1. Core Differences Among the Three Generations

First Generation: Split Structure (Double-row angular contact ball bearing/tapered roller bearing combination)

Early gasoline-powered vehicles (pre-2000) mostly employed a split design consisting of two sets of single-row bearings and a hub. These components required on-site assembly at the vehicle manufacturer. The inner ring had an interference fit with the axle shaft, while the outer ring had an interference fit with the wheel hub. Nut preload was used to control clearance. The disadvantages of this design are that assembly precision relies on manual labor (clearance errors can easily exceed ±0.02mm), poor sealing performance, and the bearings are susceptible to water ingress and corrosion in muddy or flooded roads. Their service life is typically limited to 80,000-120,000 kilometers. Typical applications include the front wheel hub bearings of early Santana and Jetta models, which utilize a double-row angular contact ball bearing (7206AC) assembly, requiring regular inspection of the preload nut.

Second Generation: Integral Double-Row Bearings (Flanged Outer Ring)

After 2000, the industry introduced the integral double-row design, integrating the outer rings of the two bearings into a single piece with a built-in flange for bolting to the wheel hub. The inner ring remains separate. This design simplifies vehicle assembly (eliminating the need for on-site clearance adjustment), improves sealing performance (using a double-sided contact rubber seal, 2RS), and extends service life to 150,000-200,000 kilometers. For example, the Toyota Corolla's front wheel hub bearing (model DAC40800040) utilizes a double-row angular contact ball bearing structure with a radial dynamic load rating of 58kN, capable of withstanding radial loads of 1.5 times the vehicle's weight. Furthermore, by optimizing the raceway curvature radius (ratio of 1.05 to the roller radius), contact stress is reduced by 30%.

Third Generation: Wheel Hub Bearing Unit (Integrated Sensor and Flange)

After 2010, with the widespread adoption of ABS (Anti-lock Braking System) and ESP (Electronic Stability Program), third-generation wheel hub bearing units became mainstream. These units integrate the inner ring, outer ring, double-row rollers, cage, seal, flange (inner/outer ring integrated), and ABS sensor magnet into a single unit, enabling "install-and-use" functionality. Their core innovation lies in the integrated ABS magnet (typically with 48 or 58 teeth). Sensors collect real-time wheel speed signals, providing data support for the braking and stability systems. For example, the Volkswagen Magotan's front wheel hub bearing unit (model VKBA3569) not only boasts an increased radial dynamic load rating of 65kN, but also ensures ABS signal error of ≤1% through magnetic ring precision (pitch error ≤ 0.05mm), preventing misjudgment of braking. Today, high-end models have developed "fourth-generation intelligent units" with integrated temperature and vibration sensors to monitor bearing health in real time, providing data for predictive maintenance.
2. Core Structural Characteristics: Adapting to the Mechanical Requirements of Automotive Driving

Regardless of the generation of structure, automotive wheel hub bearings must meet three major mechanical properties:

Combined load-bearing capacity: They must simultaneously withstand radial loads (body weight; for passenger cars, the radial load on a single bearing can reach 3-5kN, and for commercial vehicles, 10-15kN) and axial loads (lateral forces during cornering and axial forces during braking; for passenger cars, the axial load can reach 1-2kN). Therefore, double-row angular contact ball bearings (passenger cars, contact angle of 15°-25°) or double-row tapered roller bearings (commercial vehicles, contact angle of 20°-30°) are often used. The contact angle is optimized to balance the two loads.

High-speed rotational stability: When a passenger car reaches 120km/h, the wheel hub bearing rotates at approximately 3000rpm (with a 17-inch tire). Vibration caused by centrifugal force must be controlled at high speeds. Through precision machining (inner ring radial runout ≤ 0.005mm, outer ring roundness ≤ 0.003mm) and dynamic balancing (residual unbalance ≤ 5g·mm), operating noise levels are guaranteed to be ≤ 55dB (ISO 16283 standard).

Strict sealing and protection: The wheel hub bearing, located in the lower chassis, must withstand corrosion from mud, water, salt (winter snowmelt), and dust. Therefore, it utilizes a double-lip seal + dust cover for dual protection. The inner sealing lip (nitrile rubber) tightly seals against the inner ring (contact pressure 0.3-0.5MPa) to prevent grease leakage. The outer dust cover (fluororubber, temperature resistant -40°C to 150°C) blocks large particles. Combined with the rust inhibitor built into the seal chamber, the bearing withstands corrosion for over 1000 hours in a salt spray test (5% sodium chloride solution).​
II. Material Processing Breakthroughs: From "Durability to Electrification Compatibility"
The selection of materials and processes for automotive wheel hub bearings must balance the three major requirements of "load-bearing strength, wear resistance, and corrosion resistance." The high torque (peak torque is over 50% higher than that of fuel-powered vehicles) and high speed (motor-driven wheel speeds can reach 6,000 rpm) of new energy vehicles further drive material processing upgrades toward "higher performance and lighter weight."
1. Core Materials: From Bearing Steel to Composite Modification
Bearing Body Material: High-Cleanliness Bearing Steel is the Mainstream
The wheel hub bearing bodies for both conventional fuel-powered and new energy vehicles are constructed with high-carbon chromium bearing steel as their core, with the mainstream grade being GCr15SiMn (corresponding to ISO 100CrMnSi6-4). Through an "860°C quenching + 180°C low-temperature tempering" process, they achieve inner and outer ring surface hardnesses of HRC60-64, roller hardnesses of HRC62-66, and core toughness ≥28J/cm² (-40°C low-temperature impact energy), ensuring fatigue life under cyclic loads (L10 life ≥ 200,000 km, per ISO 281). To meet the high torque demands of new energy vehicles, the industry has introduced "ultra-clean bearing steel" (such as China Steel Research Institute's GCr18MoVNd). Through rare earth neodymium (Nd) microalloying and vacuum degassing, the oxygen content in the steel is controlled below 5ppm (compared to 15-20ppm for conventional steel). Non-metallic inclusions (such as Al₂O₃) are ≤10μm in size, resulting in bearing fatigue life increased to 1.5 times that of conventional products. The steel can withstand instantaneous peak torques of 3000Nm (as seen in the rear-wheel drive hub bearings of the Tesla Model 3). Cage Materials: Lightweight and High-Temperature Resistance

Cages must guide rollers for uniform distribution under high-speed rotation. Traditional fuel-powered vehicles typically use stamped steel cages (SPCC cold-rolled steel), which are low-cost but heavy (accounting for approximately 15% of the total bearing weight). To reduce weight and energy consumption, new energy vehicles are increasingly adopting engineering plastic cages. The mainstream material is PA66 reinforced with 30% glass fiber, boasting a density of only 1.3g/cm³ (compared to 7.85g/cm³ for steel), resulting in an 80% weight reduction. Furthermore, the addition of polytetrafluoroethylene (PTFE) lubricating particles reduces the friction coefficient from 0.0025 to 0.0018, minimizing oil churning losses. (New energy vehicle wheel hub bearings are typically lubricated for life, lacking a separate oil supply system, requiring low-friction cages.) High-end new energy vehicles (such as the Porsche Taycan) use PEEK (polyetheretherketone) cages, which have a temperature resistance of up to 260°C and can withstand the high-temperature environments of motor-driven wheels (wheel hub temperatures can reach over 120°C). They also exhibit excellent creep resistance, with deformation of ≤0.01mm at 6000 rpm. Bearing Seat and Flange Materials: Lightweight Aluminum Alloys Are Common

The flanges of third-generation hub bearing units (used to connect the wheel hub to the suspension) are typically forged from 45# steel (tensile strength ≥ 600MPa) in conventional fuel-powered vehicles. However, new energy vehicles are shifting toward aluminum alloys to reduce weight (every kg saved increases range by 1-2 km). The mainstream material is 6061-T6 aluminum alloy. This material, formed through extrusion and subjected to T6 heat treatment, achieves a tensile strength of 310MPa and a yield strength of 276MPa, reducing weight by 60% compared to steel flanges. Furthermore, the surface is hard-anodized (with an oxide layer thickness of 10-15μm), providing salt spray corrosion resistance of over 800 hours (e.g., the front hub bearing flange of the BYD Han). 2. Key Processes: Precision Machining and Performance Optimization
Ultra-Precision Grinding: Controlling Micron-Level Accuracy
The raceways and rollers of wheel hub bearings must be machined to ultra-precision standards. This is achieved using a five-axis CNC grinding machine (such as the German JUNKER grinder). Through online grinding wheel dressing and workpiece temperature control (20±0.5°C), raceway roundness tolerances are maintained at ≤0.002mm, surface roughness Ra ≤0.02μm, and roller cylindricity tolerances at ≤0.001mm. This precision ensures uniform force distribution across the double-row rollers (contact stress deviation ≤5%), preventing premature failure caused by local overload. For example, the wheel hub bearings of the BMW 3 Series utilize this process to control operating vibration acceleration to below 0.5g (at 1000 rpm), improving NVH performance by 20%. Surface Modification: Improving Wear and Corrosion Resistance
To address rust caused by winter de-icing agents, the industry uses a "phosphating + electrophoresis" composite coating for bearing outer rings. The phosphating layer (2-3μm thick) enhances coating adhesion, while the electrophoresis layer (epoxy resin, 15-20μm thick) blocks salt intrusion, resulting in an outer ring with a salt spray resistance of over 1200 hours (compared to only 400 hours for conventional uncoated bearings).
The roller surfaces of new energy vehicles utilize "ion nitriding" to form a 5-8μm thick nitride layer (hardness HV800-1000), which doubles wear resistance and can withstand roller-raceway friction at high speeds. (For example, the rear wheel hub bearings of the NIO ES6 have a roller lifespan extended to 250,000 kilometers after nitriding.) Integrated Sensor Technology: Ensuring Signal Accuracy

The ABS magnetic rings in the third-generation wheel hub bearing units utilize an integrated injection molding process. Magnetic powder (ferrite or NdFeB) is mixed with PA66 plastic and then directly injection-molded into the grooves of the bearing inner and outer rings. The magnetic rings have a pitch error of ≤0.03mm and a magnetic flux deviation of ≤5%, ensuring a signal output accuracy of ±0.5% for the ABS sensor within a speed range of 100-6000 rpm (preventing misjudgment of wheel speed during braking). The wheel hub bearing units developed by Schaeffler for the Mercedes-Benz E-Class also feature a shielding layer (copper foil) on the outer surface of the magnetic rings to prevent signal distortion caused by electromagnetic interference from the motor.

III. Vehicle Adaptation Solutions: Differentiated Designs from "Combustion Vehicles" to "New Energy Vehicles"

The technical solution for automotive wheel hub bearings must be precisely matched to the characteristics of the vehicle. Combustion vehicles prioritize "cost control and durability," commercial vehicles focus on "heavy loads and long life," and new energy vehicles prioritize "high torque, high speed, and lightweight," forming three typical adaptation solutions.
1. Fuel-powered Passenger Vehicles: Balancing Cost and Basic Performance

The wheel hub bearings for fuel-powered passenger vehicles (such as the Volkswagen Lavida and Toyota Camry) generally utilize a third-generation unitized structure (double-row angular contact ball bearings). Key parameters and design features are as follows:

Precision Grade: P5 (ISO 492), inner ring bore tolerance controlled to -0.012/-0.025mm, ensuring an interference fit with the axle shaft (interference 0.005-0.01mm), preventing relative slip during high-speed rotation.

Load Capacity: Radial dynamic load rating of 45-60kN, axial dynamic load rating of 20-30kN, capable of withstanding a maximum load of 1.2 times the vehicle weight (e.g., a single wheel radial load on a 1.5-ton sedan is approximately 3.75kN, with a safety factor of 2.5 times reserved for the bearing).

Lubrication and Sealing: Filled with lithium-based composite grease (such as Shell Alvania EP2), with the grease volume accounting for 1/2 of the seal cavity volume. 30%-40%, combined with double-sided 2RS seals, ensures lifetime maintenance-free operation (no relubrication required during its lifecycle).
Typical models: DAC series (e.g., DAC45850045), with an outer ring diameter of 85mm, an inner ring inner diameter of 45mm, and a width of 45mm. Suitable for 15-17-inch tires, the L10 lifespan reaches 200,000 kilometers, meeting the typical operating requirements of fuel-powered vehicles. 2. Commercial Vehicles (Heavy-Duty Trucks/Buses): Heavy Loads and Long Life Prioritized

Commercial vehicles (such as the Jiefang J7 and Yutong Bus) require wheel hub bearings to withstand greater loads (single-wheel radial loads can reach 10-15kN). Therefore, third-generation units with double-row tapered roller bearings are used. Design features include:

Material Reinforcement: The body is constructed of GCr15SiMn steel, using a "carburizing and quenching" process (carburizing layer depth 1.2-1.5mm, surface hardness HRC62-64) to enhance impact resistance (capable of withstanding braking torques of 5000Nm);

Structural Optimization: The rollers feature a logarithmic profile design (with slightly convex generatrix curves) to avoid edge stress concentration and reduce contact stress by 25%. The cage is constructed of forged steel (40Cr), increasing centrifugal force resistance by three times. (Although commercial vehicle wheel hubs rotate at low speeds of approximately 800-3000 rpm, the high loads require a high-strength cage.)

Life Indicator: L10 life of up to 500,000 kilometers, meeting the commercial vehicle requirement of "million-kilometer no-major-repair." For example, the rear wheel hub bearing unit (model BT2-8010) on the Dongfeng Tianlong heavy-duty truck boasts a radial dynamic load rating of 180 kN and can withstand a single wheel load of 12 tons.

Maintenance Design: Some commercial vehicle bearings have pre-reserved grease filling ports (unlike the lifetime lubrication of passenger vehicles), requiring refilling with extreme-pressure lithium-based grease every 100,000 kilometers (such as the Great Wall Shangbo EP3) to meet the lubrication needs under heavy loads.

3. New Energy Vehicles: Adapting to High Torque and High Speed

The motor drive characteristics of new energy vehicles (especially pure electric vehicles) (high peak torque, high speed, and frequent torque fluctuations) place more stringent demands on wheel hub bearings. Typical adaptation solutions are as follows:

High-torque Design: Utilizes a "double-row tapered roller bearing" structure (such as the rear-wheel hub bearings in the Tesla Model Y), contact

The angle has been optimized to 28°, and the axial dynamic load rating has been increased to 45kN (50% higher than bearings of the same size in fuel vehicles). It can withstand the instantaneous peak torque of the motor of 3500Nm (compared to approximately 2000Nm in fuel vehicles).

High-speed optimization: By reducing the roller diameter (from 12mm to 10mm) and increasing the number of rollers (from 10 to 12), centrifugal force is reduced (30% reduction at 6000rpm). A PEEK cage (temperature resistant to 260°C) is used to prevent cage deformation at high speeds.

Electromagnetic compatibility (EMC) design: Because the motor drive generates high-frequency electromagnetic interference, an electromagnetic shielding layer (such as copper-nickel alloy foil) is added between the ABS sensor and the magnetic ring. This increases the signal-to-noise ratio of the sensor output signal to over 40dB, preventing false triggering of the ABS system.

Lightweight and low-loss: The flange is made of 6061-T6 aluminum alloy (60% weight reduction), and the bearing inner ring is made of A "hollow shaft" design (reducing weight by 15%), coupled with low-viscosity synthetic grease (such as Mobil SHC 100), reduces frictional power consumption by 25% (for every 1W reduction in frictional power consumption, range increases by 1-2 km/100 km).

Typical example: BYD Haibao's front wheel hub bearing unit (model VKBA7588) has a radial dynamic load rating of 68kN, a maximum speed of 6500r/min, and an L10 life of 250,000km. It also passes EMC testing (compliant with ISO 11452-2) and is compatible with 800V high-voltage motor systems.

IV. Fault Diagnosis and Safety Assurance: From "Reactive Maintenance" to "Active Warning"

Failure of automotive wheel hub bearings directly impacts driving safety (for example, bearing seizure can lead to wheel loss of control). Therefore, a scientific fault diagnosis system is essential to identify and address problems early. Failure modes vary depending on the characteristics of fuel-powered and new energy vehicles, requiring differentiated diagnostic methods. 1. Common Faults and Causes

Abnormal Noise and Vibration: The Most Intuitive Failure Signals

A buzzing or gurgling noise that intensifies with increasing speed (30-80 km/h) is often caused by bearing raceway wear or roller spalling. In gasoline-powered vehicles, this is often due to seal failure and water ingress (causing raceway rust and wear). In new energy vehicles, frequent torque fluctuations (sudden torque changes during motor start-stop and regenerative braking) can lead to raceway fatigue spalling. For example, a NIO ES6 owner reported "abnormal front wheel noise at 60 km/h." Disassembly revealed a 0.5mm deep spalling pit in the wheel hub bearing raceway. This was caused by motor torque fluctuations, which caused contact stress to exceed the material fatigue limit (2000 MPa). Abnormal ABS signal: A fault unique to the intelligent unit.

If the ABS fault light on the dashboard illuminates, it's likely due to wear on the wheel hub bearing's magnetic ring, excessive sensor clearance (normal clearance is 0.5-1.0mm; over 1.5mm causes signal interruption), or electromagnetic interference. New energy vehicles have strong electromagnetic radiation from their motors. If the shielding layer is damaged, sensor signal distortion can occur. (For example, in the BYD Han's ABS false alarm case, a cracked shield caused high-frequency interference, resulting in a 10% deviation in the speed signal.)

Excessive temperature: A warning of lubrication failure.

After driving, touch the wheel hub (turn off the engine and allow it to cool down). If the temperature exceeds 80°C (normal is around 50-60°C), it's likely due to grease aging (grease viscosity decreases at high temperatures, causing lubrication failure) or excessive interference (the interference between the inner race and the axle shaft exceeds 0.02mm, causing frictional heating). Due to the higher wheel hub temperatures of new energy vehicles (heat dissipation from the motor), grease ages more quickly (shortening lifespan by 30% compared to fuel-powered vehicles). Therefore, regular reading of bearing temperature data via the OBD interface is required (supported by some models).

Rust and Seizure: A Typical Failure in Harsh Environments

After using de-icing agents in winter, if seals are damaged and salt intrudes into the bearings, this can cause rust on the raceways and rollers—manifesting as wheel stalling and, in severe cases, bearing seizure. (For example, a fuel-powered vehicle in northern China experienced bearing seizure and rust three months after salt intrusion due to a scratched seal lip.) Due to the high integration of wheel hub bearings in new energy vehicles, repair costs for rusted wheel hubs are higher (replacing the entire unit costs approximately 2,000 yuan, while repairing separate bearings in fuel-powered vehicles costs approximately 500 yuan). 2. Diagnosis and Maintenance Strategy
Daily Diagnosis: Combining Sensory and Simple Tools

Drivers can make a preliminary diagnosis by listening, looking, and feeling: Listen for unusual noises while driving (whether they vary with speed); check tire wear (bearing failure can cause uneven tire wear; tread wear exceeding 1.5mm on one side should be considered); and feel the wheel hub temperature after driving (over 80°C requires repair). Professional repair shops use a vibration detector (which measures vibration in the 1-5kHz frequency band; over 1.2g requires replacement) and an ABS signal tester (which measures speed signal error; over 2% requires sensor clearance adjustment). Standard Maintenance: Differentiated for Vehicle Types

Fuel Vehicles: No regular relubrication is required (lifetime lubrication). Check seal condition (for cracks and leaks) every 60,000 kilometers. Check ABS sensor clearance every 150,000 kilometers.

New Energy Vehicles: Read bearing temperature and vibration data via OBD every 80,000 kilometers (some models, such as Tesla, support remote diagnostics). Check electromagnetic shielding integrity every 120,000 kilometers. Avoid direct washing of wheel hubs with high-pressure water jets to prevent water ingress into seals.

Commercial Vehicles: Replenish extreme pressure grease every 100,000 kilometers. Check bearing preload every 200,000 kilometers (use a torque wrench to check wheel nut torque; approximately 500-600 N·m for heavy trucks and 300-400 N·m for buses). Replacement Precautions

When replacing wheel hub bearings, strictly control the interference fit (0.005-0.01mm between the inner ring and the axle shaft, 0.01-0.015mm between the outer ring and the wheel hub). Avoid hard hammering (a hydraulic press is required). Wheel hub bearing units for new energy vehicles require recalibration of the ABS sensor (using a dedicated diagnostic instrument, such as the Volkswagen ODIS system). Failure to do so will cause the ESP system to fail.

V. Future Trends and Industry Value: Technological Innovation Driven by Electrification

As vehicles upgrade toward "electrification, intelligence, and lightweighting," the technological development of automotive wheel hub bearings will focus on achieving "smarter, lighter, and more adaptable to electrification." Their industrial value will be further enhanced with the popularization of new energy vehicles. 1. Technology Trends: Three Major Directions Leading Innovation
Intelligence: From "Function Integration" to "Status Awareness"
Next-generation wheel hub bearing units will integrate more sensors—in addition to ABS, they will also incorporate tire pressure sensors (to directly monitor tire pressure, eliminating the need for a separate TPMS module), temperature sensors (to monitor wheel hub temperature in real time to prevent thermal runaway), and torque sensors (to provide feedback on wheel drive torque and optimize motor control). For example, Schaeffler is currently developing an "intelligent wheel hub bearing unit" that transmits bearing status data (temperature, vibration, and speed) to the vehicle control system via the Internet of Things, enabling "predictive maintenance" (providing warning of failures up to 1,000 kilometers in advance). This unit is expected to enter mass production in high-end new energy vehicles in 2025. Lightweighting: A Double Breakthrough in Materials and Structures
To further reduce weight, the industry is exploring "composite bearings." For example, using carbon fiber reinforced plastic (CFRP) to manufacture bearing outer rings (with a density of only 1.6g/cm³, 79% lighter than steel) in combination with ceramic rollers (silicon nitride Si₃N₄, with a density of 3.2g/cm³, 59% lighter than steel) can reduce overall weight by over 50%. (For example, BMW is currently testing CFRP wheel hub bearings for the iX electric vehicle.) Furthermore, topological optimization (such as a hollowed-out outer ring structure) can further reduce weight while maintaining strength. It is expected that lightweight wheel hub bearings will reach 50% penetration in new energy vehicles by 2030. Electrification Adaptation: Higher Performance and Compatibility
For 800V high-voltage motors and four-wheel drive (4WD) systems, wheel hub bearings will further enhance torque carrying capacity (peak torque exceeding 4000Nm), temperature resistance (withstanding wheel hub temperatures of 180°C), and electromagnetic compatibility (EMC Class 3). Furthermore, to accommodate "in-wheel motors" (motor integrated within the wheel hub), the industry will develop "ultra-thin wheel hub bearings" (width reduced from 45mm to 30mm), reserving installation space for the motor. The wheel hub bearing market for in-wheel motor vehicles is expected to reach 5 billion yuan in 2027.

2. Industry Value: The "Core Support" of China's Automotive Industry

As a core automotive component, the scale of the wheel hub bearing industry is highly correlated with vehicle production. The global automotive wheel hub bearing market was projected to reach US$38 billion in 2024, with China accounting for 45% (approximately US$17.1 billion), making it the world's largest market. Chinese companies (such as Renben Group, Wanxiang Qianchao, and Wafangdian Bearing Group) have achieved localization of third-generation wheel hub bearing units. These products have reached internationally advanced performance levels (for example, Renben's new energy vehicle wheel hub bearings boast an L10 lifespan of 250,000 kilometers and meet Class 2 EMC standards). These products are priced at only 60%-70% of imported products (from Schaeffler and SKF), effectively replacing imports for fuel-powered vehicles and mid- and low-end new energy vehicles.

In the new energy vehicle sector, Chinese wheel hub bearing companies are accelerating their expansion into the high-end market. Wanxiang Qianchao supplies wheel hub bearing units for the BYD Haima and NIO ES6, while Wafangdian Bearing Group develops wheel hub bearings compatible with 800V systems for the Ideal L9. It is projected that the localization rate of wheel hub bearings for new energy vehicles in China will reach 80% by 2025, a 40 percentage point increase from 2020. At the same time, with the "14th Five-Year Plan" requiring "independent control of core components," Chinese wheel hub bearing companies will further increase their R&D investment (reaching over 5% of total R&D investment by 2024), achieve breakthroughs in high-end material technologies such as ceramic rollers and CFRP outer rings, and drive the industry's transformation toward high-end and intelligent driving.

Conclusion
Although compact (typically 40-100mm in diameter), automotive wheel hub bearings are the "precision heart" of the vehicle's driving system. From basic load-bearing in fuel-powered vehicles to high-torque adaptation in new energy vehicles, and finally to future intelligent sensing, their technological evolution has consistently resonated with the advancements of the automotive industry. As China's automotive industry transitions toward electrification and intelligent driving, wheel hub bearings are not only the cornerstone of safety but also the key to improved performance. With continued breakthroughs in material processing and the integration of intelligent functions, automotive wheel hub bearings will further unlock their value, injecting new impetus into the efficient and green development of the global automotive industry.