ANALYSIS OF TRANSMISSION CHARACTERISTICS OF COSINE GEAR DRIVE

Based on the mathematical model of a novel cosine gear drive, a few characteristics, such as the contact ratio, the sliding coefficient, and the contact and bending stresses, of this drive are analyzed. A comparison study of these characteristics with the involute gear drive is also carried out. The influences of design parameters including the number of teeth and the pressure angle on the contact and bending stresses are studied. The following conclusions are achieved： the contact ratio of the cosine gear drive is about 1.2 to 1.3, which is reduced by about 20% in comparison with that of the involute gear drive. The sliding coefficient of the cosine gear drive is smaller than that of the involute gear drive. The contact and bending stresses of the cosine gear drive are lower than those of the involute gear drive. The contact and bending stresses decrease with the growth of the number of teeth and the pressure angle.     

齿轮弯曲强度有限元精确分析方法研究

通过计算轮齿弹性共轭接触迹,确定齿轮在啮合过程中各个位置的压力角、齿廓接触长度以及接触位置等参数。并对ANSYS进行二次开发,制作了一个精确计算齿轮弯曲强度有限元分析的软件。运用此软件对相同参数的渐开线齿轮与点线啮合齿轮进行弯曲强度的有限元精确计算,得出点线啮合齿轮比渐开线齿轮弯曲强度提高11.7%的结论。     

旋转齿轮瞬时接触应力和温度的分析模拟

建立了高速齿轮传动轮齿瞬时接触温度的分析方法和模型;采用赫兹接触理论和有限元接触分析方法分析了标准渐开线齿廓和齿顶修形齿廓的齿面接触压力;研究了啮合过程中轮齿的相对滑动速度和齿面摩擦因数以及摩擦热流密度的计算方法;建立了轮齿本体温度的有限元温度分析模型;计算了轮齿接触面的瞬时温升;分析了标准和齿顶修形渐开线齿轮的轮齿本体温度和瞬时接触温度及相关因素对它们的影响。     

基于有限元方法的WN齿轮啮合仿真与接触分析

研究对WN齿轮进行接触强度与啮合仿真分析。采用先进的齿轮啮合和接触的计算机仿真分析技术对复杂的空间多点接触的WN齿轮啮合与强度特性进行研究,研究从齿形创成开始,建立啮合模型,采用3维有限元方法计算WN齿轮轮齿弹性变形与接触应力,进行WN齿轮啮合过程的计算机仿真分析。首次提出用法向啮合间隙和Un it分割方法进行接触分析,实践表明方法是非常有效的。研究还针对不同尺度的WN齿轮的实际啮合状况进行了具体的接触应力和接触区域的解析计算,开发了用于该齿轮机构分析的实用软件。     

齿轮接触强度的研究及基于Visual Basic语言的程序设计

根据齿轮啮合原理和接触力学,深入研究了渐开线齿轮传动啮合过程中各啮合点的接触应力计算,研究了不同参数齿轮传动最大接触应力可能出现的啮合位置,分析了国家标准(GB/T 3480-1997)接触强度计算公式,指出了国家标准中接触应力计算公式的局限性,提出了更加全面的确定和计算最大接触应力的方法;并运用Visual Basic语言和Microsoft Visual Basic6.0软件,编制了齿轮接触强度的计算程序;程序为计算齿轮的几何参数、接触应力及接触强度校核提供了快捷的工具,可以大大提高了齿轮设计的效率.     

The frictional losses in involute gears as predicted from the traction-slip characteristics of lubricating oils

Variations in the curvatures at the point of contact, the sliding velocity and the transmitted force of gear teeth together with experimental traction-slip characteristics of lubricating oils obtained from disc machine tests are used to calculate the instantaneous frictional losses over the total path of contact in involute gears. The method is explained and a numerical example is given.     

硬矮齿形（JD型）双圆弧齿轮的断齿现象的分析

目前几乎所有船舶的主推进箱中都采用了渐开线齿轮，随着船舶功率不断增大，必须采用渗碳淬硬的渐开线齿轮。制造这种齿轮，必须磨齿以保证较高的齿轮精度，从而提高了生产成本。１９８６年起，我们在２６００马力２００００吨级推轮中采用倒顺离合硬矮齿双圆弧齿轮箱，成功完成了各种试验，根据实践与分析表明，这种齿轮具有很高的接触强度和抗弯强度。本文将着重介绍硬矮齿双圆弧齿轮用于船舶主推进齿轮臬在实船试验发生的断齿现象     

COMMON DEFINITION FOR END-SURFACE CONTACT RATIO OF GEARS AND ITS APPLICATIONS

Common definition and calculating expressions of end-surface contact ratio for all type of gears are put forward, and with calculation expressions for involute gears, micro-segments profile gears, and sine-curved profile gears being discussed. The end-surface contact ratio of gears is defined as the ratio of the action angle (the rotation angle of gear from gear-in to gear-out for one pair of teeth) to the rotation angle per pitch (or central angle per tooth). According to the theory of gearing, equation of the meshing line can be deduced from the tooth profiles of basic rack. Having obtained the equation of the meshing line, and being given the addendum outline of the gears, the contact ratio can be calculated with the calculation expressions. For the involute gears, this definition has same effect as the well-known definition: ratio of the contact line to the base pitch. This definition of contact ratio is also suitable to other non-involute gears, such as micro-segments profile gears, sine-curved prof     

RV减速器的动力学模型与固有频率研究

建立ＲＶ减速器的动力学模型并推导运动微分方程,通过求解振动方程得到系统的固有频率,并就针轮齿数对ＲＶ减速器振动的影响等进行了研究,得到对ＲＶ减速器的设计和应用具有指导意义的结论。     

渐开线斜齿圆柱齿轮弹流润滑模型的建立

渐开线直齿圆柱齿轮的弹流润滑问题已经基本成熟，而对同样是线接触的渐开线斜齿圆柱齿轮的弹流润滑求解却研究甚少并颇有争议。分析了斜齿轮齿廓曲面的形成及啮合特点，建立了研究渐开线斜齿圆柱齿轮弹流润滑的物理模型和数学模型．通过数学推导，得到了膜厚方程，通过多重网格法即可获得渐开线斜齿圆柱齿轮在某一瞬时的弹流润滑数值解。     

Simulation of wear in gears with flank interference—a mixed FE and analytical approach

Gears in precision mechanisms, such as industrial robots, are often designed to have no backlash. Deviations from the ideal gear geometries and unfavourable deformations during operation may cause interference between interacting tooth flanks, resulting in high and strongly varying friction. Mild wear of the tooth flanks may improve such conditions. Therefore, this theoretical study has been conducted of wear in spur gears with interference. A mixed finite element (FE) and analytical approach is used. The FE method is used to determine contact loads between the interacting gear teeth. The main drawback with FE analyses of this type of problem is normally the computation time needed. Therefore, a novel FE meshing method is used, giving a dense FE mesh in the contact regions and a coarse mesh in the rest of the teeth. Based on the FE determined loads between the interacting teeth, the contact pressures and the contact widths are then easily determined using analytical expressions based on Hertz theory. The wear of a point on a tooth flank is determined by integrating the product of sliding distance and contact pressure during the time it is in contact with its mating flank.The results show that the wear of the gear tooth flanks may eliminate the interference and consequently the high and strongly varying friction will decrease dramatically. However, the transmission error will change, since the gears will not preserve their accurate involute profiles.     

双渐开线齿轮齿面啮合与误差影响分析

本文研究了双渐开线齿轮的齿面展成方法和几何特性 ,采用计算机辅助分析的方法实现了双渐开线齿轮的齿面啮合分析 ,对比分析了双渐开线齿轮与渐开线齿轮的瞬时啮合线的特点 ,研究了制造和安装误差对双渐开线齿轮的影响规律 ,提出了补偿由于制造和安装误差引起的双渐开线齿轮啮合位置偏离和运动误差的途径。     

Geometric design of involute spur gear drives with symmetric and asymmetric teeth using the Realized Potential Method

The index gear drive potential is defined for the estimation of the quality of spur gear drives as a maximum contact ratio obtained at the contact of teeth profiles along the full line of action. In this paper, a new method is proposed for the geometric design of symmetric and asymmetric involute meshing in which the contact ratio of the gear drive is equal to its potential. This method is appropriate for the geometric design of spur gears with a small teeth number and is based on the generalized model of involute meshing. The gear drive potential is assigned as an input value, from which, after appropriate calculations, the geometry of rack-cutters, gears and involute meshing can be determined. Using the proposed method, the areas of the realized potential and the areas of the existence of involute gear drives are defined. In addition, many numerical examples are solved. In the cases of symmetric and asymmetric meshing, the minimum teeth number is obtained when the gear drive potential is larger than one.     

精确载荷分布下斜齿轮三维建模及弯曲应力分析

从范成法加工齿轮的原理出发,利用三维建模软件建立了渐开线斜齿圆柱齿轮的精确模型。根据齿轮啮合变形协调方程,利用线性规划法求解了齿轮副在各啮合节点的载荷分布情况,并计算了轮齿间的载荷分配率。利用有限元软件ANSYS计算了完整齿轮模型在啮合过程中的最大齿根弯曲应力,为齿轮弯曲强度校核提供了依据。研究结果发现,斜齿轮的最大弯曲应力有可能出现在多齿啮合的区域,这种现象与直齿轮有所不同。     

齿间摩擦对机床渐开线齿轮支座振动之影响

由于不计齿间摩擦,机床机械传动领域内一直近似认为,只要主动轮输入扭矩保持恒定,渐开线齿轮支座就不会产生振动。研究表明,由于齿间存在摩擦,齿轮支座反力属性生财藏一变化,为此,机床渐开线层座会产生一定程度的强迫振动。文章指出,降低齿间摩擦系数并适当减小啮哈 角是减缓甚至避免机床齿轮支座振动的有效措施。     

非对称渐开线直齿轮设计计算CAD系统的开发

通过对非对称渐开线圆柱直齿轮齿根弯曲应力的分析,结合接触强度的计算公式,建立了系统的数学模型。以模块化设计思想为指导,用Delphi7这个可视化的,面向对象的编程语言为开发工具,开发了用户界面友好的圆柱齿轮设计系统。该系统可以对非对称和对称齿轮进行设计、校核.提高了设计质量．减少了设计工作量．为后续的非对称齿轮零件参数化绘图提供了重要设计参数。     

微线段齿廓齿轮的弯曲强度分析

介绍了微线段齿轮的形成原理,建立了微线段齿轮有限元计算的力学模型,论证了计算中的奇点问题,并提出相应的解决方案,用正交试验法设计了一组算例并用有限元法进行计算,从而说明微线段齿轮的弯曲强度确实要优于渐开线齿轮。     

Stress calculation for plastic helical gears under a real transverse contact ratio

Calculation methods of plastic helical gears with a real transverse contact ratio have never been studied in depth. The methods used in some references assume a uniform load distribution along the line of contact or don’t take into consideration the effect of premature mesh between one or more pair of teeth during engagement, which is not in good agreement with numerical results. This paper is focused on analysis of plastic helical gears. The nonuniform load distribution obtained from the proposed mathematical model is based on the calculation of the real contact ratio representing the real number of pairs of teeth in contact. This model also leads to the distribution of the tooth bending stress and the contact stress along the area of contact.     

基于UG的渐开线-圆弧齿轮的数学建模及仿真

从传统的渐开线齿轮出发,讨论其存在的传动问题,从而引出了对齿廓进行修形的渐开线-圆弧齿轮。首先,基于UG/NX参数化地建立齿轮模型,理论上对比分析了渐开线-圆弧齿轮与渐开线—直齿轮的弯曲应力。其次,在UG/NASTRAN环境下进行接触应力的仿真分析,并且将仿真结果与理论计算进行比较,验证仿真的正确性。最后,从理论上说明了渐开线-圆弧齿轮对弯曲疲劳寿命的改善。通过本文的研究,将为渐开线-圆弧齿轮的优化设计及实际加工制造提供理论依据。     

凹形圆锥渐开线齿轮的滚齿法

凹形圆锥渐开线齿轮 (ConcaveConicalInvoluteGear)是一种新型的圆锥渐开线齿轮 (ConicalInvoluteGear) [1～ 3 ] 。圆锥渐开线齿轮的齿面间呈点接触[4] ,所以齿面强度比低 ,而凹形圆锥渐开线齿轮的齿面呈凹状 ,齿面间呈椭圆状面接触[3 ] ,克服了圆锥渐开线齿轮齿面强度低的弱点 ,同时又具备圆锥渐开线齿轮的全部优点。这种新型齿轮不仅能实现平面齿轮机构的功能[5] ,也能实现空间齿轮机构的功能[6] ,具有替代传统的非渐开线型空间齿轮机构的可能性 ,所以是一种极具发展前景的机械传动零件。目前加工凹形圆锥渐开线齿轮均采用先滚齿成圆锥渐开线齿轮然后再逐一把齿面磨齿成凹形的加工方法[7] ,这种两步加工方法 ,比传统的手工修型加工方法 ,已是极大的进步 ,可是凹形圆锥渐开线齿轮的加工依然存在成本高 ,周期长 ,精度低等问题。为此有必要确立凹形圆锥渐开线齿轮的高精度的一步加工方法。本研究首先从理论上确立了凹形圆锥渐开线齿轮的滚齿加工法 ,然后利用上述理论 ,实际加工了一组凹形圆锥渐开线齿轮 ,以证明了凹形圆锥渐开线齿轮的滚齿加工法的可行性及正确性