【作者】 黄安贻；

【导师】 张仲甫；

【作者基本信息】 武汉理工大学 ， 机械设计与理论， 2002， 博士

【摘要】 平面二次包络环面蜗杆副在机械工业朝着高速、重载、高效方向发展的背景下产生，是机械传动的基础件。这种蜗杆副由于多齿啮合、瞬时双线接触、综合曲率半径大、接触线与相对滑动速度夹角大等特点，因此承载能力大、传动效率高、易自动润滑、使用寿命长。 传统上，为使蜗杆副共轭齿面间为线接触，必须采用对偶范成法加工蜗轮轮齿。蜗轮滚刀设计制造周期长、制造困难，导致蜗杆副开发周期长、成本高。本文提出了平面二次包络环面蜗杆副非对偶加工的基本设想，并开展相关研究工作，取得了以下主要成果及创新点： 1、建立了用于平面二次包络环面蜗杆副数控加工的五轴机床模型。改变联动方式并更换刀具后，可以在该机床上分别加工蜗杆和蜗轮。这样，可以用通用刀具加工出蜗轮齿槽，实现蜗杆副的非对偶加工。 2、在范成法加工中，一般地，蜗杆作为原创件首先被加工出来，在跑合中，蜗杆齿面充当“二次切削刀具”，因此，应保证蜗杆齿面的加工精度和适合的表面粗糙度。本文定义了理想蜗杆和蜗杆加工时的对刀平面，计算理想蜗杆的螺旋角，实现对平面包络环面蜗杆的数控加工时的平面刀具姿态控制和对刀、多头蜗杆分头、两回转轴的转角及速度控制，这是保证蜗杆齿形正确和齿面精度的关键。 3、当蜗轮齿面上存在非工作区时，则很难用准确的数学方程描述蜗轮啮合面，为了统一处理，本文提出了用虚拟加工的方法建立蜗轮的三维实体模型，用截面法对蜗轮齿槽曲面进行离散化处理，用Bézier曲面片逼近理论齿面。这样既有利于数控加工刀具轨迹的生成，又便于提取可加工性信息。 4、提出了平面二次包络环面蜗杆副可制造性评价的内容和方法。可制造性评价贯穿于设计的每一个阶段，根据平面二次包络环面蜗杆副的特点，本文以啮合性能最佳、蜗轮齿冠体积最小作为设计时的评价指标，利用多目标优化获得满意解。同时，根据计算机视觉原理，计算蜗轮齿槽曲面上CC点的可视方向范围检查刀具干涉、控制刀具姿态，并根据CC点处的主曲率、加工精度要求等计算切削行宽。更多还原

【Abstract】 ’ Plane--generated doub1e enve1oping Hourg1ass worm gear drive,as a kind of basic mechanical transmission unit, was inventedunder the background that the mechanica1 industry deve1oped in’ the direction of high speed, heavy 1oad and high efficiency. Itmeshes with multip1e teeth, and two contact 1ines exist betweeneach pair of coup1ing gears. Additiona11y, this kind of drivehas great 1ubrication ang1e, that is to say, the ang1e betweenthe tangent direction of the contact 1ines and the re1atives1iding ve1ocity is great. More over, the worm gear pair has thecharacteristics of worm gear drive have such exce11entproperties as heavy 1oad capacity, high efficiency, ease ofbeing lubricated, 1ong service 1 if e, and soon.Traditiona11y, the worm whee1 teeth are machined by dua1generating method to ho1d the contact 1ines between the couplingteeth. It takes 1ong deve1oping time and high cost to deve1opthe worm drive because of the difficulties and 1ong period forthe deve1oping of the hobbing cutter. Therefore, it presents newgenerating method to machine the p1ane--generated doub1eenve1opiflg Hourg1ass worm gear drive us ing NC machi ne too1. Thi sdissertation invo1ves the main aspects of the research, whichachieves the fo11owing positive resu1ts.1. A 5--axes NC machine too1 was mode1ed for the machining ofthe p1ane--generated double enveloping Hourg1ass worm gear drive.By mean of changing the cutter and gearing the axes of the NCMachine tool, the worm and the whee1 can be respective1y machinedusing the same NC machine too1. The worm are ground whi1e theteeth of the whee1 can be finished using genera1cutters--mi 11ers.2. Genera11y, the mating surfaces of the worms are "secondarycutters" for meshing surfaces of the worm whee1s during the2..runn1flg--1n per1od of the worm gear drive. This imp1ies theimportance of high fini shing precision and appropriateroughness for the mating surfaces of the worms. Thisdi ssertation defines the ideal worm and positioning p1anes forthe machining of the worm. It a1so ca1cu1ates the spira1 ang1eof the ideal worms. The definitions and the calculations help to control the inclination angle of the planar cutter, to locate the start point of the planar cutter, to control the turning velocities of the axes of the NC machine tool, and to machine multiple threads of the worms when NC machining is carried out to generate the planar enveloping toroid worm. These key measures gain the high precision of the worm mating surfaces.3. It is hard to mathematically describe the meshing surfaces of the plane-generated double enveloping Hourglass worm gear wheel teeth owing to the existence of non-working areas. A 3D solid model is found to describe this kind of worm wheel teeth by mean of virtual machining. The obtained meshing surfaces of the worm wheel teeth, which can be treated as ideal meshing surfaces, are fitted in Bezier surfaces after discretization by cut planes. Using this information model, editing the NC tool path and extracting the machinability information of the wheel teeth can be easily implemented.4. The evaluation contents and relevant methods are proposed for the manufacturability of plane-generated double enveloping Hourglass worm gear pairs. This kind of worm gear drive is usually applied to transmit power, so that its performances are of great importance for transmission efficiency and service life. Meanwhile, the wheel teeth are generally made of expensive nonferrous metals. It indicates that the performances should be as good as possible while the volume of the wheel should be possibly small. Goal attainment is employed in this dissertation to acquire the satisfying solution in the developing stage of the gearing arrangement. Moreover, according to the principle of computer vision, it calculates the visibility direction of cutter contact (CC) point on the wheel mating surface so to check the cutter interference and to control the cutter angles. While NC programming, the path w更多还原