Each driving wheel of a steam locomotive is connected by coupling rods. The connection point on each wheel is not at the axle center, and combined with the weight of the rod itself, this causes the center of gravity of each wheel to shift.
When the locomotive runs at high speeds, this imbalance leads to significant axle wear and periodic downward impact forces on the rails. To resolve this, designers implemented partially solid wheel structures, with varying solid sections to rebalance each wheel's center of gravity.
The small wheels at the front are guide wheels, while the large red wheels behind are driving wheels. The black box between them is the cylinder. Inside the cylinder, steam builds up to a pressure of several atmospheres, pushing pistons that drive the wheels.
The driver controls the train by adjusting the steam pressure and intake. In addition to the driver, there's a fireman onboard responsible for fueling the boiler. At full speed, the fireman must maintain a strong fire to ensure continuous steam generation.
A steam locomotive consists of two main parts: the front is the steam engine with the boiler at its core, where water is heated into steam; the rear is the tender, which stores coal and water.
A steam locomotive typically weighs over 100 tons, and the tender adds another 40 to 50 tons. This tremendous weight enables the locomotive to pull hundreds or even thousands of tons of cargo or passenger cars.
Today, forging is the most advanced method for mass-producing locomotive wheel hubs. Heated aluminum billets are repeatedly pressed under high pressure to form rough hub shapes. These are then spin-formed to stretch the rim to required specifications.
After machining, polishing, and painting, the final product is completed. Compared to cast hubs, forged hubs offer superior fatigue resistance, impact strength, and overall durability, while both types perform similarly in heat dissipation.
MTJ is committed to delivering high-quality products and solutions for the global railway industry. Our product range includes wheels, axles, wheelsets, locomotive tyres, rings, steel rails, bearings for rail transit vehicles, bogies, railway wagons, and spare parts. With advanced R&D capabilities and rigorous quality control, we ensure that every product meets international standards, supporting railway transportation worldwide.
