Passenger Train Wheels: Structure and Functions

Passenger train wheels are the ultimate load-bearing components of railway passenger cars. Their primary role is to transfer the load of the passenger car to the rails and to roll along them, enabling smooth operation. The condition of the wheels is one of the most critical factors influencing both the safety and ride quality of railway passenger transport.

Modern passenger trains use monoblock rolled steel wheels, which are composed of several key parts: tread, flange, rim, web, hub, and hub hole. Each component serves a specific purpose in ensuring reliable performance:

◆ Flange: The raised edge along the inner side of the tread. It guides the wheel along the rail and plays a vital role in preventing derailment.

◆ Tread: The surface where the wheel contacts the rail. Designed with a slight taper, it ensures smooth rolling and stability.

◆ Rim: The thickness of the wheel along the tread’s circumference. It provides strength to the tread and reserves material for re-profiling during maintenance.

◆ Web: The plate-shaped connection between the rim and hub, usually S-shaped, that supports the wheel’s structure.

◆ Hub: The central part that fits tightly onto the axle and connects to the web. As the backbone of the wheel, it supports the entire assembly.

◆ Hub Hole: The hole designed for mounting the axle seat, manufactured with an interference fit to ensure secure installation.

By combining precision engineering and robust materials, passenger train wheels ensure safe, reliable, and efficient railway operations.