三峡升船机齿条弯曲应力计算方法及测试技术研究

发布时间：2018-04-02 12:03

本文选题：齿条齿根应力　切入点：折截面法　出处：《机械科学研究总院》2015年硕士论文

【摘要】：齿条特别是大模数齿条在重大工程装备中的应用越来越多,而且模数也越来越大,如三峡升船机齿条模数高达62.67mm,然而目前尚无计算齿条齿根应力的精确计算方法。现有标准多采用将齿条视为无穷大的渐开线齿轮的方法来计算齿条齿根应力,对于中小模数的齿条具有实用性和近似准确性,但当模数较大特别是大于50mm时,缺乏相应的试验数据作为支撑,计算公式中的参数可能不再适用,严格意义上来说,现有标准己不适用大模数齿条齿根应力的准确计算。研究表明,对于齿根经硬化处理的齿轮,裂纹萌发源可能会由齿根表面转移到齿根次表面,因此齿根内部的应力计算就显得尤为重要。因此,对齿条齿根表面应力、齿根内部应力的准确计算方法及齿条齿根应力测试技术的开发研究具有重要的理论价值和工程应用背景。本文主要研究内容和结论有：(1)对齿根应力计算的平截面法、折截面法、有限元法进行了对比分析。研究表明：平截面法仅能计算齿根表面最大应力值；折截面法既能计算齿根表面应力值也能计算齿根内部应力值,并且比平截面法有更高的准确性；有限元法能清晰的获得轮齿的应力分布,可作为齿根应力分析的一个重要手段。(2)对现有折截面法计算模型进行修正。为考虑齿根圆角引起的应力集中对齿根应力分布的影响,本文引入应力渗透因子概念,采用积分方法推导出了齿根弯曲应力、齿根压应力计算公式。并结合折截面法数学模型进一步分析了影响齿根应力计算准确性的若干因素。(3)齿条齿根过渡曲线上应力最大点处切线角的影响因素分析。对不同齿形角、齿根圆角半径、模数、加载点位置、载荷大小的齿条进行有限元分析。研究表明：齿形角、齿根圆角半径、加载点位置对齿根最大应力点的切线角有较大影响：模数、载荷大小对齿根最大应力点的切线角基本无影响。(4)齿轮齿条啮合刚度对齿间载荷分配及最恶加载点的影响规律研究。对齿轮齿条啮合过程的啮合刚度进行分析,得出不同相位下的轮齿啮合刚度。在考虑基节误差的情况下,三峡升船机齿轮齿条的最恶加载点位于单齿啮合上界点。(5)应力渗透因子的确定。采用试验与相似理论相结合的方法计算应力渗透因子值,并通过有限元方法验证了相似理论的正确性。(6)三峡升船机齿条齿根应力测试。根据试验转速和载荷控制策略确定测试齿的位置,并利用有限元对齿条齿根应力进行分析,得出三峡升船机齿条齿根应力分布规律,确定应变片的粘贴位置。(7)三峡升船机齿条齿根应力测试数据分析。根据齿根应力分布规律,确定有效齿根应力测试点。利用最小二乘法对试验数据进行拟合,得出齿根应力与载荷的关系。将试验测试值、折截面法计算值、有限元分析值进行对比分析。结果表明,齿根内部应力折截面法计算值与有限元法结果基本吻合,齿根表面应力的折截面法计算值与实测值相差小于5%。上述研究表明,本文对三峡升船机的齿根应力测试方法是可行的。试验和有限元分析的结果均表明本文提出的齿根应力折截面法修正计算模型是准确的。主要研究内容和结论,为大模数齿条弯曲强度的进一步研究奠定了重要技术基础。
[Abstract]:Rack especially large modulus rack is used more and more in great engineering projects, and the module is also growing, such as the Three Gorges ship lift rack modulus of up to 62.67mm, but there is no accurate calculation method of rack tooth root stress. The existing standard rack as infinite involute gear to calculate rack the root stress, practical and approximate accuracy for small modulus gear, but especially when the modulus is larger than 50mm, the lack of the corresponding test data as a support, may no longer be suitable for calculating the parameters in the formula, strictly speaking, the existing standard is not suit for accurate calculation of large modulus rack tooth root stress. The research shows that the root of the hardened gear crack source may be transferred by the adorable root surface to the root surface, so the root of internal stress calculation is particularly Important. Therefore, the rack tooth surface stress, accurate calculation method of tooth root stress and internal force test of root rack should develop technology has important theoretical value and application background. Main contents and conclusions of this paper are: (1) to calculate the stress on the tooth root cross section method, fold section method the finite element method are compared and analyzed. The results show that: the cross section method can only calculate the root surface of the maximum stress value; fold section method can calculate the tooth surface stress value can also be calculated root internal stress value, and it is more accurate than the plane cross section method; finite element method can obtain a clear tooth the stress distribution, can be used as the root should be an important means of analysis. (2) of the existing folding section calculation model was modified. In order to consider the fillet stress concentration caused by the effect of the stress distribution of the tooth root, this paper introduces the stress permeability for The concept, derived the tooth root bending stress using integral method, calculation formula of tooth root stress. And combined with some factors break section method mathematical model in order to analyze the influence of tooth root stress calculation accuracy. (3) gear tooth root transition curve on Influencing Factors of stress at the point of maximum tangential angle analysis of different tooth. Angle, fillet radius, modulus, loading position, loading rack for finite element analysis. The results show that: the tooth profile angle, fillet radius, the tangential load point on the root of the maximum stress point angle has great effect: the modulus, tangent load on the root of the maximum stress point angle has no effect. (4) study the influence on the load distribution between the teeth and the worst load point of the gear meshing stiffness of gear meshing process. The meshing stiffness of gear meshing analysis, obtained under different phase in consideration of stiffness. Basepitch error under the condition of the worst load point of Three Gorges ship lift gear rack is located in the upper bound of the single tooth meshing point. (5) determine the stress permeability factor. By using the method of test and similarity theory combined with the stress calculation of permeability factor value, and the correctness of the similarity theory is verified by finite element method. (6 The Three Gorges ship lift rack) root stress test. According to the test of speed and load control strategy to determine the test tooth position, and analyze the stress on the tooth rack using finite element, the Three Gorges ship lift rack tooth root stress distribution, strain gauge to determine the adhesive position. (7) Three Gorges ship lift rack tooth root stress analysis stress test data. According to the tooth root stress distribution, determine the effective root stress test. The experimental data were fitted using the least squares method, the tooth root stress and load. The test value, the calculated value discount section method, Comparative analysis of finite element analysis. The results showed that the root of the internal stress fracture section method calculation results and the finite element method is consistent with the calculated value is less than 5%., the study shows that the measured and fold section stress on the surface of root, the root of Three Gorges ship lift stress testing method is feasible. And the finite element analysis results show that the proposed root should be revised calculation model of stress section method is accurate. The main research contents and conclusions, and provide an important technical basis for further research on the bending strength of large modulus rack.

【学位授予单位】：机械科学研究总院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U642

【相似文献】