【作者】 张满栋；

【导师】 吕明；

【作者基本信息】 太原理工大学 ， 机械电子工程， 2010， 博士

【摘要】 齿轮制造创新技术的研究和应用,是提高齿轮传动质量的关键环节。齿轮的齿形及齿距误差,直接影响其传递扭矩的能力。齿面的微观几何形貌,则对齿轮传动产生的噪声,以及使用性能和寿命影响很大。为了提高现有齿轮的承载推力,各国普遍采用硬齿面技术,即通过提高齿面硬度以缩小装置的尺寸。对于渐开线淬硬齿面齿轮精加工,我国现行的方法主要是采用磨齿或软珩齿。磨齿加工虽能满足齿形精度要求,但其生产效率低、成本大,导致产品竞争力下降,并且齿面的微观几何形貌也不利于降低齿轮的传动噪声。而软珩轮基体是弹性体,因而导致软珩轮的静态精度在珩齿时将遭到破坏,并倾向于服从齿坯的精度,导致软珩齿加工质量不稳定。用超硬材料立方氮化硼(CBN)与金属结合剂电镀于钢质基体上,制成的电镀CBN硬珩轮,由于其基体具有很好的刚性,使得被加工齿轮不仅可明显改善表面质量,而且对齿形误差、齿向误差、周节累积误差等可得到有效校正,加工效率也将显著提高。然而,由于种种原因,用电镀CBN硬珩轮对淬硬齿面精加工,还存在诸多问题亟待探讨和解决,硬珩轮的珩齿机理以及硬珩轮的制作技术也未得到圆满解决。本文在此方面进行了一些深入探讨,并得到一些有益的结论,为推广电镀CBN硬珩轮对淬硬齿面的加工技术具有重要的现实意义。本文主要进行了以下几方面的工作:运用齿轮啮合、微分几何、磨削加工、摩擦学、弹性力学等理论,推出了珩齿加工珩削深度的计算模型和各个相关参数的计算方法,实现了对珩齿加工齿形误差的理论预测,揭示了硬珩齿加工齿形误差(如中凹和挖根误差)形成的内在因素,这一切均与实际相吻合。实现了珩磨轮和齿轮的参数化建模和参数化装配,对构成珩磨轮齿面的渐开线实现样条化处理,并对样条上的型值点实现了参数化,为珩磨轮齿面优化修形奠定了基础。运用有限元动态分析软件,根据实际加工条件确定模型的边界条件,对电镀CBN硬珩轮珩齿过程进行了动态仿真分析,通过对接触应力数据的采集,得到了接触应力沿啮合点的分布图,进一步揭示了齿面接触应力波动造成齿形误差的内在原因,也揭示了因重叠系数不同即齿数变化,造成齿形误差的差异。运用有限元静态分析方法,揭示了被珩齿轮齿面法向变形趋势,也从另一方面揭示了齿形误差趋势。利用有限元分析及优化软件,对珩磨轮齿面进行优化修形,通过对样本点回归分析,得到了齿形修改参数的最佳值,反馈到珩磨轮CAD模型,实现了珩磨轮齿面修形,齿面接触应力分布有了较大改观,为指导生产实践提供了有力保障。研究表明,采用电镀CBN硬珩轮珩齿加工,在齿形中部(尤其在齿数较少时),因接触应力波动较大,会产生齿形“中凹”误差,而在齿根部分,因珩削滑移距离最大,接触应力也较大而产生“挖根”误差,在珩磨轮制作方面应考虑上述因素,从而达到降低齿形误差,提高珩齿加工质量的目的。毫无疑问,这些研究结论对生产实践有重要的指导意义。更多还原

【Abstract】 The research and application of gear innovative manufacturing technologies is key to improve the transmission quality of gear. Gear tooth shape and pitch error, will be directly affecting their ability to transfer torque. Tooth surface morphology of micro-geometry will be greatly influencing the noise of transmission, performance and life in the use. In order to improve the existing gear bearing ability, the hardened tooth surface technology is used by many countries, that is by increasing the hardness of tooth surface to reduce device size.For quench hardened involute gear finishing, our current method is to use grinding or soft gear-honing. Although the grinding process can meet the precision of tooth profile, but its low productivity, high cost, leading to less competitive, and the tooth surface morphology of micro-geometry is not conducive to reducing the transmission gear noise. The matrix of soft honing wheel is elastomer, resulting in its static accuracy will be decreased, and tend to obey the precision of gear blanks, causing instability of soft gear-honing processing quality.With superhard materials of cubic boron nitride (CBN) and the metal plating on the steel matrix, made-up electroplated CBN hard wheel, because its rigidity matrix is a very good, making surface quality of gear to be machined could not only improve, but also the profile error and lead error, the cumulative pitch error and other can be corrected, processing efficiency will be improved significantly.However, for various reasons, hard honing wheel with electroplated CBN finishing on the quenching hardened gear, there are many problems that must be explored and resolved, gear-honing mechanism of hard honing wheel and the process techniques of hard honing wheel has not been satisfactorily resolved. In the paper, some depth investigation and some useful results were gotten, for the promotion of electroplating CBN hard honing wheel on the quench hardened gear finishing technology has important practical significance.This article was the following areas:Based on the gear meshing, differential geometry, grinding, friction, elasticity and other theories, educed out calculation model of honing cutting depth, and given out the calculation method of various parameters in the model, realized the theoretical prediction on the tooth profile error, revealed the internal formation factors of the tooth profile error (such as the concave and the dig root error) in gear-honing processing, all of thus match to the practice.The parametric modeling of gear-honing wheel and gear, and parametric assembly were achieved, the involute constructed of tooth surface of honing wheel was converted into spline, and the fit points on the spline was parameterized, for honing teeth surface modification optimized was possible.By the dynamic finite element analysis software, according to the actual processing conditions setting the model boundary conditions, the dynamic simulation of gear-honing process was done with electroplating CBN hard honing wheel, through the tooth contact stress data collection, contact stress distribution at engaging points has been drafted, further revealed the internal factors of the tooth profile error caused by the tooth surface contact stress fluctuations, also revealed changes in profile error caused by the difference of contact ratio for the different number of teeth. By the static finite element analysis, revealed the gear surface normal deformation trend, it also revealed the profile error in the other side.In the help of finite element analysis and optimization software, the tooth surface of honing wheel was optimally modified, through regression analysis of the sample points, the value of the best parameters to modify tooth profiles were obtained, back to the CAD model of honing wheel, the tooth surface modification of the honing wheel was achieved, tooth surface contact stress distribution had been greatly improved, as the guide provided a strong guarantee for the production practice.With electroplating CBN hard honing wheel, studies show that on the tooth middle (especially when there are fewer in number of teeth), fluctuations due to contact stress will result in tooth "concave" error, and in parts of the tooth root, as honing cutting the maximum slip distance, contact stress is also larger and have a "dig root" error, in the honing wheel production, these factors should be considered to achieve the lower profile error and increase the quality of the purpose of honing process. There is no doubt that these findings have important guidance to production practice.更多还原