本SAE推荐规程旨在作为标准试验的定义，标准试验可能会随着经验和技术进步而频繁更改。在考虑使用时，应牢记这一点。SAE 2号摩擦试验机用于评估自动变速器盘式离合器与汽车变速器油液的摩擦特性。它还可用于对湿摩擦系统进行耐久性测试。本文件的具体目的是定义mPVT试验，以评估湿摩擦系统性能随速度、温度和压力的变化。本程序旨在作为供应商和最终用户的标准。摩擦系统的供应商或用户选择的唯一变量是:a.摩擦材料；b、 流体；c.反应板。在报告测试结果时，必须明确这三个变量。如果本文件中所述的任何试验参数或系统硬件发生变化（摩擦材料、试验流体或反应板除外），则不得报告使用本文件获得的数据。 本程序旨在评估端点/中点比率、中点和分离系数。该程序可用于演示不同接合速度、油底壳温度和施加压力水平之间发生的变化。参考SAE J2487、SAE J2488或SAE J2489，了解功率水平变化引起的系数变化。如表1所述，该程序由四个50循环的磨合水平组成，以3500 r/min的速度，随着施加压力的增加，依次为16个水平，包括25个动态啮合和一个在第25个动态循环完成后的磨合。通过改变初始啮合速度、施加压力和油底壳温度，同时将惯性保持在0.701 kg-mu2恒定，可达到16个水平。

This SAE Recommended Practice is intended as the definition of a standard test, which may be subject to frequent change to keep pace with experience and technical advances. This should be kept in mind when considering its use.The SAE No. 2 Friction Test Machine is used to evaluate the friction characteristics of automatic transmission plate clutches with automotive transmission fluids. It can also be used to conduct durability tests on wet friction systems.The specific purpose of this document is to define a mPVT Test for the evaluation of the variation of wet friction system performance as a function of speed, temperature, and pressure. This procedure is intended as a standard for both suppliers and end users.The only variables selected by the supplier or user of the friction system are: a. Friction Material; b. Fluid; and c. Reaction Plates.These three variables must be clearly identified when reporting the results of this test. If any of the test parameters or system hardware as described in this document are changed, other than the friction material, test fluid, or reaction plates, the data may not be reported as having been obtained using this document.This procedure is intended to evaluate the endpoint/midpoint ratios, midpoint and breakaway coefficients. The procedure can be used to demonstrate changes that occur between the different levels of engagement speed, sump temperature and apply pressure. Refer to SAE J2487, SAE J2488, or SAE J2489 for coefficient variations due to changes in power level.The procedure, as described in detail in Table 1, consists of four 50 cycle break-in levels at 3500 r/min with increasing steps of apply pressure, followed by 16 levels consisting of 25 dynamic engagements and one breakaway following completion of the 25th dynamic cycle. The 16 levels are achieved by varying initial engagement speed, apply pressure and oil sump temperature while the inertia is kept constant at 0.701 kg- m\u2.