Electric power steering system ( eps ) , a new type of vehicle steering system , which emerged in recent years , is an advanced technology which synthesizes modern control technologies , incorporation of machine & electricity and latest electronic technologies 电动助力转向系统( eps )是近年来出现的一种新型动力转向系统，是一项综合了现代控制枝术、机电一体化及现代电子技术等技术的高新技术。
In this paper , the author improved the design of v trough of port plate by studying the automobile power steering pump ( apsp ) produced home and abroad and analyzing the different reasons of their noise from the stator transition curve , which could reduce the noise of apsp effectively 本文以国内和国外生产的汽车动力转向泵为研究对象，从定子过渡曲线的角度分析了它们噪声不同的原因，并对配流盘v形尖槽进行了优化设计，可以有效地降低汽车动力转向泵的噪声。
Cooper standard automotive , a multi - national comp - any whose business covers sealing systems , nvh ( noise , vibration and harshness ) control systems , and fluid handing systems ( brake pipe , brake & fuel bundles fuel lines power steering assemblies , heating and cooling , emission control , and others with all the advanced production equipments as well as research facilities 库博汽车配件有限公司是一家国际性的汽车配件生产型公司，在全球均设有同汽车配件相关的生产及科研设施，涵盖的产品包括密封系统、减震系统、流涕承载系统（刹车管路、燃油管路、动力转向系统、加热冷却系统、废气再循环等系统） 。
The apsp produced abroad is made by numerical controlled machine tool , which has noise level of 71db ( a ) , the apsp produced in our country is made in the method of exploratory which has noise level of 73db ( a ) and 75db ( a ) . in order to analyze the influence of stator curve to noise , the author used tri - coordinate measuring instrument to measured exactly the inside surface of stator and got the straddling point coordinate , and made curve fitting by using matlab as language and studied the fitting effect and then worked out the equation of stator transition curve in return seeking , then comparied this method with the standard style and made the conclusion : the equation of atator transiting curve of apsp made by numerical controlled machine tool is close to theorical 5 power curve standard style , but compared with it , the stator transiting curve of apsp produced in exploratory has a major error . combining the testing results of noise , one can know that the qualily of stator transition curve play an importance to t he noise of the pump 国外生产的汽车动力转向泵是用数控机床加工的，其噪声值为71db ( a ) ，国内生产的汽车动力转向泵是用靠模方法加工的，其噪声值分别为73db ( a )和75db ( a ) ，为了分析定子曲线对泵的噪声的影响，本人用三坐标测量仪对定子内表面进行精密测量，获得定子内表面的离散点坐标，以matlab语言为工具对离散点进行曲线拟合，观察拟合效果，然后，用回归方法求出了定子过渡曲线的方程，并把该方程与理论方程标准型进行了比较，得出如下结论：用数控机床生产的汽车动力转向泵的定子过渡曲线方程非常接近理论5次曲线标准型，而用靠模方法加工的汽车动力转向泵的定子过渡曲线与理论5次曲线标准型相比较，则存在着较大的误差，结合噪声测试结果可知，定子过渡曲线的优劣，对泵的噪声大小有着重要的影响。
The 3d coordinate measurement machine form usa , universal tool microscope from germany , intellectual flatness check device , metalloid graphic analyzer , electric and pneumatic measurement instruments and high performance steering test equipment ensure the products quality and play the important role for the products development 从国外进口的三坐标测量仪、德国万能工具显微镜、智能平面度检查仪、金相图像分析系统、电动量仪、气动量仪和日本的高性能动力转向系统试验设备，保证动力转向器的性能质量。
