Are Wheels Rotating or Rolling?

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The wheels of a moving car undergo rotational motion, which is a rotational phenomenon. The rotation of car tires is a rotational phenomenon, while the movement of the car body is a translational phenomenon. The sliding friction between the ground and the outer tire of the wheel assembly provides a static friction force, while the interaction between the hub and the wheel assembly involves sliding friction. When a car is driving on the road, the wheels exhibit rotational motion, while the movement of the car body is a translational phenomenon. Car tires are one of the essential components of a vehicle, directly in contact with the road surface. Together with the car suspension, they help absorb shocks during driving, ensuring good ride comfort and smoothness. They also ensure strong adhesion between the wheels and the road, improving traction, braking, and maneuverability, while bearing the weight of the car. The critical role of tires in automobiles is increasingly recognized. The principle of car wheel steering involves turning the steering wheel, which drives the rotation of the steering shaft and the steering transmission shaft. This torque is input into the steering gear, amplified and reduced, then transmitted to the steering arm, and further conveyed through the steering tie rod to the steering knuckle arm and the tie rod, causing both wheels to turn at a certain angle simultaneously. Specific details are as follows: The function of the car steering system: Ensures the car can move straight or turn as intended by the driver. Types of car steering systems: Mechanical steering system, power steering system. Components of the car steering system: Steering control mechanism, steering gear, steering linkage. Relationship between the turning angles of both steering wheels: During a turn, to avoid additional resistance caused by wheel slippage and reduce tire wear, the steering system must ensure all wheels perform pure rolling, meaning the extension lines of all wheel axes intersect at a single point. Part of the car steering structure: The half-shaft passes through the center of the steering knuckle, and the steering kingpin is divided into upper and lower sections. The steering knuckle housing connects to the upper and lower kingpins, allowing left and right swinging. The steering control mechanism adjusts the steering knuckle's deflection via the steering knuckle arm, thereby driving the wheels to turn and achieving car wheel steering.