Reliability and Efficiency of Electric Vehicle Transmissions

电动汽车(EV)设计对电动汽车变速箱施加了特别苛刻的摩擦学条件。这包括在一个极端的高扭矩和低齿轮速度的组合，以及在另一个极端的相对低扭矩的非常高的速度。此外，冷却要求需要非传统的润滑液，一些最新的润滑剂是专门为这种应用开发的，其中含有大量的水。这导致轴承和齿轮等传动元件在恶劣的摩擦学条件下工作，同时也增加了喷油损失。该项目致力于优化电动汽车变速器的效率和可靠性。它建议设计一种模型，能够预测适用于电动汽车的变速器中的摩擦学条件和总功率损失。至关重要的是，该方法将包括对齿轮和轴承运行的详细处理，以便准确预测这些部件的运行寿命和摩擦损失。这将包括使用目前使用或正在开发的用于电动汽车变速器的润滑油的测量流变性。该项目的总体目标是：-通过优化变速器结构(传动比数量、传动比分配、重量)来提高电动汽车的效率，从而增加电动汽车的续航里程，以便为给定的车辆负荷提供足够的输入-输出匹配。-优化电动汽车润滑油配方，在保持耐用性的同时，将变速箱功率损失降至最低(从而扩大车辆续航里程)。润滑剂的考虑将涉及摩擦学性能、冷却、电气性能和材料兼容性。

Electric vehicle (EV) design imposes particularly harsh tribological conditions on EV gearboxes. This includes the combination of high torque and low gear speed at one extreme and very high speeds with relatively low torques at another. In addition, cooling requirement call for unconventional lubricating fluids, with some of the latest lubricants developed specifically for this application containing significant amounts of water. This results in harsh tribological conditions in transmission elements such as bearings and gears while also increasing oil churning losses. This project is concerned with optimising efficiency and reliability of EV transmissions. It proposes to devise a model which is able to predict the tribological conditions and the overall power losses in transmissions suitable for use in electric vehicles. Crucially, the approach will include a detailed treatment of gear and bearing operation in order to accurately predict operational lifetimes and friction losses in these components. This will include the use of measured rheological properties of lubricants currently used or being developed for use in EV transmissions.The overall aims of this project are:- To improve the efficiency and hence increase the range of EVs through optimising transmission architecture (number of ratios, ratio split, weight) required to provide adequate input-output matching for a given vehicle duty. - To optimise EV lubricant formulation to minimise gearbox power losses (and hence extend vehicle range) while maintaining durability. Lubricant considerations will address tribological performance, cooling, electrical properties and material compatibility.