机械

在货车简化转向架中，斜楔是提供抗菱刚度的核心结构。为研究斜楔磨耗对临界速度的影响，本文提出斜楔多刚体动力学模型。该模型将斜楔主、副摩擦面离散为若干节点，分别计算各节点的几何位移，以确定摩擦面接触载荷分布。其次，建立考虑斜楔多刚体动力学的车辆-轨道耦合动力学模型，并重点分析了斜楔磨耗对转向架抗菱刚度及临界速度的影响。主要结论如下：(1)当斜楔总磨耗低于临界磨耗量时，车辆临界速度随磨耗的增加略微下降；当磨耗达到临界磨耗量时，临界速度发生突降并显著降低；进一步增加磨耗后，临界速度维持在较低水平。(2)为确保车辆临界速度超过130 km/h，不同磨耗模式下的斜楔临界磨耗量存在差异：均匀磨耗及垂向不均匀磨耗的临界磨耗量均为6 mm，而横向不均匀磨耗使临界磨耗量降低至5 mm。

In the simplified bogie of freight vehicles, the wedge is the core structure that provides anti-diamond stiffness and increases the critical speed of the vehicle. To study the influence of the wear of the wedges on the critical speed of the freight vehicle, this paper proposes a multi-rigid-body dynamic model of the wedges. This model discretizes the friction surfaces of the wedge into several nodes, and calculates the geometric displacement of each node separately to determine the distribution of contact load on the friction surface. Based on this, a vehicle-track coupling dynamic model considering the multi-rigid-body dynamics of the wedges is further established, and the influence of the wedge wear on the critical speed of the vehicle is analyzed in detail. The main conclusions are as follows:(1) When the total wear of the wedge is lower than the critical amount, the critical speed of the vehicle decreases slightly with increasing wear. When the wear reaches the critical amount, the critical speed suddenly drops sharply. As the wear increases further, the critical speed remains at a lower level.(2) On the condition that the critical speed of the vehicle exceeds 130 km/h, the critical wear amount of the wedge varies under different wear modes. The critical wear amount for uniform wear and vertical uneven wear is both 6 mm, while horizontal uneven wear reduces the critical wear amount to 5 mm.