Influence of dynamic unbalance of wheelsets on the dynamic performance of high-speed cars

Abstract

With further increasing in running speed of newer high-speed EMUs (electric multiple units), higher demand for wheelset dynamic balance is required. In order to study the influence of the dynamic unbalance of wheelset on the stability, ride quality, and curving performance for a high-speed car, a detailed dynamic model of a high-speed EMU car is established using the software SIMPACK. The analysis results indicate that the dynamic unbalance of the wheelset significantly influences the dynamic performance of the high-speed car. The increase in dynamic unbalance of the wheelset will decrease the hunting critical speed, worsen the vertical ride quality, and increase the wheelset lateral force, derailment coefficient, and wheel unloading ratio. Therefore, in order to improve the stability, ride quality, and running safety of high-speed car, the values of dynamic unbalance of wheelset should be strictly controlled in manufacturing, and periodically monitored in operation.

Prototype Development for Predicting Eccentricity Based on Rotating Unbalanced Behavior of Train

“…So that when the wheel rotates at a certain speed, the centrifugal force (F) eccentricity of the wheel can be expressed as in Eq. ( 1) [4], [11], where, F is Force (N), M is wheel mass (kg), n is wheel rotational speed (rpm), and e is Eccentricity (mm).…”

“…The main reason can be several factors, such as microstructural differences in materials, asymmetry of the wheels, inaccurate wheel profiles caused by asymmetrical wear (wheels out of roundness), wheel assembly errors, the main inertia axis passing through the wheelset's center of gravity which is not parallel to the wheelset. wheelset axis of rotation [4]. One of the examples is an imbalance of centrifugal force that occur when the wheel rotates, because of an imbalance in the wheel mass.…”

“…One of the examples is an imbalance of centrifugal force that occur when the wheel rotates, because of an imbalance in the wheel mass. Centrifugal force is one of the important factors causing bearing wear, train noise and vibration, and the most fatal can cause the train to derail [4], [5].…”

Unbalance identification for mainshaft system of 2-DOF precision centrifuge: A displacement sensor-based approach

“…It should be noted that there exists a special form of dynamic unbalance in which the static and couple unbalance vectors lie in the same plane, which is called quasi-static unbalance and defined as U quasi−static , where the central principal axis intersects the axis of rotation, but the mass center does not on the axis of rotation. For more information on the concepts about dynamic unbalance, see [20,21] and the references therein.…”

Dynamic Analysis of Railway Vehicle with Wheel Unbalance

“…Du (5) 는 고속 철도차량에 대한 윤축의 동적 불 평형 평가를 위해 회전체역학의 관점에서 윤축 설계를 검토하였다. Wang (6) Abstract: When the center of mass of a railway wheel is not aligned with the geometrical center of the wheel axis, wheel unbalance occurs. If a railway vehicle runs without removing the wheel unbalance, vibrations will be produced.…”