TLDR: An axle is a central shaft that connects and supports rotating wheels or gears on vehicles. It can either be fixed to the wheels or fixed to the vehicle with the wheels rotating around it. Axles are important for the movement and stability of vehicles.
An axle is like the backbone of a vehicle. It connects the wheels or gears to the rest of the vehicle, allowing them to rotate and move. In some cases, the axle rotates with the wheels, while in others, the wheels rotate around the axle. This depends on how the axle is fixed to the vehicle.
There are different types of axles used in vehicles. In a solid axle system, the axle is connected to the wheels and also supports the weight of the vehicle and any cargo. This type of axle is commonly found in trucks and heavy-duty vehicles. In contrast, a non-driving axle, like the front beam axle in some trucks, serves as a suspension and steering component but does not transmit driving torque.
In modern vehicles, especially cars, axles are often part of independent suspension systems. This means that the position and angle of the wheel hubs are independent of the axles, allowing for a smoother ride and better traction. In these systems, the axles primarily transmit driving torque to the wheels, while the suspension system controls the wheel movement.
Axles can be made from different types of steel, depending on their intended use. Chrome-moly steel is commonly used for its strength and resistance to bending or breaking. Carbon steel is another type of steel used for axles.
In addition to the main axles that support the wheels, there are also lift axles that can be mechanically raised or lowered. These axles are often used in dump trucks and trailers to increase weight capacity or distribute weight more evenly. They can be lifted off the ground when not needed to save wear on tires and increase traction.
Overall, axles play a crucial role in the movement, stability, and weight distribution of vehicles. They are an essential component of the chassis and suspension system, ensuring that the wheels can rotate and the vehicle can move smoothly.