Author: Site Editor Publish Time: 2025-07-17 Origin: Site
The selection of the wheel flange and tread profile of train wheels not only affects the wear and service life of the wheel forgings on the track but also directly influences the curve negotiation performance and running quality of the equipment. The flange ensures that the wheels can reliably pass through curves and switches without derailment.
The tread is conical, with a 1:10 taper near the rolling circle. When navigating curves, the outer wheel rolls on the outer rail with a larger diameter near the flange, while the inner wheel rolls on the inner rail with a smaller diameter. This design allows the wheels to follow the track direction for guidance while compensating for the difference in length between the inner and outer rails due to the varying rolling distances.
During straight-line running, if the wheelset deviates from its central position on the track, the difference in rolling radii between the two wheels will cause the wheelset to recenter itself. The outer part of the tread has a steeper 1:5 taper, which increases the difference in rolling radii, making it easier to navigate sharp curves. Reducing the tread taper helps suppress hunting motion (lateral oscillations), but it significantly accelerates flange wear, shortens wheel reprofiling intervals, and reduces wheel service life. This approach is only adopted in some high-speed passenger trains.
On the other hand, the wheel flange and tread profile experience rapid initial wear during operation but gradually stabilize, with wear slowing down over time. Even after reprofiling, the restored shape does not last long, and the metal removal volume is substantial. Therefore, some railways have adopted a tread profile that closely resembles the worn and stabilized shape, known as a hollow tread or worn-profile tread. This design not only reduces wheel wear and extends reprofiling cycles but also improves wheel-rail contact conditions, thereby lowering contact stress.
