The working principle of automotive wheel hub units is mainly based on the rolling contact and sealing protection of bearings, transmitting torque and bearing load through the rolling of balls or rollers, and ensuring operational stability through lubrication and sealing design, as follows:
Core structure and function: The wheel hub unit is composed of components such as wheel hub, bearings, seals, etc. It serves as the connecting hub between the wheel and the axle, reducing friction through rolling contact of bearings, supporting the weight of the vehicle body, and transmitting power. For example, wheel hub bearings use double row tapered rollers or angular contact ball structures, utilizing steel balls to roll on the inner and outer raceway or flange to achieve efficient transmission.
Power transmission mechanism: When the vehicle is in motion, the torque generated by the engine or electric motor is transmitted to the wheel hub unit through the transmission shaft, and the bearings convert the rotational motion into the rotation of the wheels. For example, the double row bearing unit optimizes the raceway design to ensure that the contact angle between the inner and outer rings matches the steel ball, thereby improving torque transmission efficiency.
Load bearing and buffering: The wheel hub unit needs to withstand the weight of the vehicle body and road impact loads, and the bearings reduce local wear by dispersing stress. For example, seals in wheel hub units can prevent impurities such as mud and water vapor from entering, protect the performance of bearing grease, and prevent metal fatigue or fracture caused by lubrication failure.
Sealing and lubrication system: Seals (such as lip, labyrinth, or combination) prevent external contaminants from entering while also preventing grease leakage.
Advantages of integrated design: Modern wheel hub units integrate sensors (such as wheel speed sensors, temperature sensors) to monitor real-time parameters such as speed and temperature, and support systems such as ABS and traction control. For example, Hall wheel speed sensors generate frequency voltage by sensing the rotation of the signal disk, achieving accurate measurement of wheel speed.