直齿轮齿廓修形的实验研究

对3种不同齿廓修形参数的渐开线直齿轮进行了振动和噪声的传动实验研究。实验结果表明，按下述原则设计的修形直齿轮具有较好的减振降噪效果：不计误差的理论设计修形齿轮的最大综合修形量应能消除含误差齿廓轮齿在啮入和啮出位置产生的几何干涉，理论设计修形齿轮的静态传动误差应保持最小的幅值变化。     

直齿轮减振修形优化设计

为了提高齿轮副实际齿面啮合性能,设计齿廓修形曲面,与理论齿面叠加构造了直齿轮实际修形齿面,结合TCA、LTCA技术,建立考虑啮入冲击、刚度激励的直齿轮弯扭耦合的多齿对振动模型,以传动误差幅值、啮合冲击、啮合线向相对加速度均方根最小进行多目标优化,设计了最佳修形齿面。研究表明:无修形齿轮的传动误差幅值随载荷增加而增大,修形后随载荷增加重合度逐渐增大,幅值会产生波动,然后保持稳定,修形后直齿轮啮入啮出端载荷明显降低,因此啮合冲击降低;该方法确定的齿轮修形参数精确、有效,能大幅度减小齿轮的振动。     

天文望远镜传动直齿轮齿廓修形设计

采用高次幂、短修形方式设计望远镜传动直齿轮,既满足重合度要求,又可改善齿轮的静传动误差,还能消除齿顶刮行现象,避免应力集中。定义空载传动误差设计曲线为齿廓修形参数,根据虚拟加工过程,建立修形齿廓方程。采用轮齿接触分析理论,结合有限元法,计算了空载传动误差曲线、齿轮承载变形曲线以及静传动误差曲线、并计算了定载荷情况下,考虑齿距误差的齿廓修形方程。结合仿真算例,对比未修形齿轮与修形齿轮的静传动误差以及主动轮齿顶处的应力,表明修形效果明显。     

齿轮修形对大功率风电增速器传动误差的影响研究

以某大功率风电增速器为研究对象,介绍了齿轮微观修形的基本理论。应用Romax软件建立风电增速器整机模型,分析了轮齿修形前后齿面的应力分布情况,给出了使动态传动误差波动较小的齿向修形和齿廓修形的范围。对比分析了齿面微观修形方式对传动误差的影响,研究了轮齿修形对传动误差影响的基本规律。在此基础上,给出了相同修形参数不同载荷工况下传递误差的变化趋势。结果表明,合理的轮齿修形量能够有效改善由于制造误差和轴变形造成的齿面偏载现象,同时降低了传动误差的波动,为风电增速器轮齿修形提供了参考。     

齿轮综合修形方法的研究

在齿轮副传动过程中,弹性变形和安装误差是造成传动误差的主要来源,通过分析齿廓修形和齿向修形的不足,提出了一种新型的修形方法——综合修形,来提高齿轮副传动平稳性与承载能力;根据轮齿啮合弹性变形的规律确定了综合修形的相关参数,并推导出其计算公式.最后用有限元方法验证了综合修形可以明显改善齿轮副的齿面受力状态.     

直齿轮传动多工况多目标修形优化设计

针对直齿轮多工况使用情况,研究了小轮修形齿面理论建模方法和直齿轮传动多工况多目标修形优化方法,进行了两种工况下直齿轮传动多工况多目标修形优化设计,并进行了修形和不修形齿轮的齿面啮合仿真,通过对比分析,验证了齿面优化修形后达到了较好的综合性能,两种工况下的承载传动误差波动幅值和最大闪温均明显下降.研究成果为提高直齿轮综合性能的修形设计奠定了基础.     

基于Romax的轮齿修形与啮合性能分析试验

以某变速箱一级齿轮副为研究对象,通过专业齿轮分析软件Romax对齿轮副进行精确建模,在模拟工况下对轮齿进行啮合性能分析,基于传动误差,齿向载荷的分析结果,利用齿轮修形数学模型确定综合修形量,并以传动误差平稳性,齿向载荷分布均匀性作为评价指标。经过修形,传动误差峰值降低了95%,齿向载荷分布变得均匀,且集中在齿宽中部。有效的改善了齿轮传动的平稳性,提高了齿轮穿的承载能力,达到了降振,减噪的目的。     

人字齿轮直线型对角修形设计及成形磨原理

为了降低承载传动误差波动产生的振动激励，提出了成形磨人字齿轮直线型对角修形优化设计。根据ISO对角修形定义，计算齿顶、齿根修形起始线在旋转投影面上的螺旋角，将修形曲线设计为直线型，给定最大修形量，确定对角修形的齿面方程。利用齿面接触分析和轮齿承载接触分析，以工作载荷下人字齿轮承载传动误差波动量最小为优化目标，采用遗传算法优化对角修形参数。确定以目标修形齿面法向偏差的平方和最小的目标函数，以螺旋角、模数、压力角为设计变量，采用遗传算法分别对齿顶和齿根修形区域进行逼近，从而实现对角修形的成形磨加工。结果表明，人字齿轮直线型对角修形可以将承载传动误差波动量降低到36.65%；采用三截面砂轮成形磨的理论误差控制在1μm以内，获得较高的齿面精度；试验人字齿小轮齿的检测结果控制在4级精度以内，并进行了齿轮副的滚检试验，从而验证该方法的有效性。     

直齿轮齿距误差与齿高修形综合设计

定义空载传动误差设计曲线为齿高修形参数,根据虚拟加工过程,建立修形齿廓方程,以最小化静传动误差波动幅值为目的,推导定载荷条件下,无齿距误差齿轮的齿高修形参数公式.采用轮齿接触分析理论求解包含齿距误差的空载传动误差,建立包含齿距误差的修形齿轮有限元模型,计算各啮合位置因承载变形引起的传动误差,在满足无齿距误差齿高修形参数公式的基础上,以设计平滑的静传动误差曲线为目的,建立齿距误差与齿高修形参数的约束方程.算例中,含齿距误差的无修形齿轮静传动误差曲线有阶跃误差,通过修形设计,消除阶跃误差,获得平滑的静传动误差曲线.     

望远镜方位锁转频率分析与动力学模型简化

定义空载传动误差设计曲线为齿高修形参数,根据虚拟加工过程,建立修形齿廓方程,以最小化静传动误差波动幅值为目的,推导定载荷条件下,无齿距误差齿轮的齿高修形参数公式.采用轮齿接触分析理论求解包含齿距误差的空载传动误差,建立包含齿距误差的修形齿轮有限元模型,计算各啮合位置因承载变形引起的传动误差,在满足无齿距误差齿高修形参数公式的基础上,以设计平滑的静传动误差曲线为目的,建立齿距误差与齿高修形参数的约束方程.算例中,含齿距误差的无修形齿轮静传动误差曲线有阶跃误差,通过修形设计,消除阶跃误差,获得平滑的静传动误差曲线.     

修形直齿轮的啮合干涉与啮合间隙

修形直齿轮因误差因素在齿对的啮入和啮出位置会出现啮合干涉或啮合间隙。本文利用齿对的啮合变形与齿廓法向修形量、齿廓误差的关系,推导了啮合齿对在啮合线的啮入和啮出位置所存在的几何干涉或啮合间隙,得到了啮合重合度小于2和3的齿轮副啮合齿对的最大干涉量或间隙量的计算表达式,为分析修形直齿轮的啮合状态和修正齿轮修形参数奠定了基础。     

Simulation of meshing for the spur gear drive with modified tooth surfaces

The authors have proposed methods (lead crowning and profile modification) for modifying the geometry of spur gears and investigated the contact pattern as well as the transmission errors to recommend the appropriate amount of modification. Based on the investigation, dynamic load of the modified spur gear drive has been calculated, which is helpful to predict the life of the designed gear drive. Computer programs for simulation of meshing, contact and dynamics of the modified spur gears have been developed. The developed theory is illustrated with numerical examples.     

三环传动的弹性啮合、载荷分配和强度计算

在考虑内啮合齿轮副齿廓理论间隙、轮齿弹性变形的基础上，建立了三环传动弹性啮合实际接触齿对数及各齿间载荷分配的理论分析模型，提出了在齿轮强度计算中计入弹性啮合效应系数的方法，并按照静强度校棱的方法考虑了制造误差的影响。通过实验间接验证了弹性啮合效应的存在。弹性多齿啮合可显著提高三环传动的承载能力。     

含侧隙齿轮副的动载荷分析

以振动理论为基础，提出一种考虑齿轮拍击振动的齿轮动载荷的数值计算方法。建立计算动载荷的齿轮冲击模型，在模型中考虑了齿轮正、反冲击时实际的啮合刚度，并给出啮合柔度的计算方法。分析在考虑静态传递误差、啮合刚度、侧隙、摩擦力及外部扭矩变化等多种激励时，作用在轮齿上的动态载荷以及整个齿轮上的综合动态载荷的计算公式。最后通过实例分析作用在轮齿上的动态载荷、综合动态载荷变化规律以及相关激励参数对动态载荷的影响。     

直齿锥齿轮齿廓修形

根据啮合刚度和噪声之间的关系,以修形减振降噪为目的,用旋转渐开线曲线对直齿锥齿轮进行齿廓修形.以减小齿轮传动误差和啮合刚度的波动大小为衡量标准,同时确保载荷变化呈平稳过渡.静态计算结果表明,直齿锥齿轮齿廓长修形具有较好的减振效果.直齿锥齿轮采用冷精锻进行齿廓修形,显著地降低了成本,这为齿轮传动系统的修形、减振、降噪和设计提供了一种新的研究方法.     

Statistical modification analysis of helical planetary gears based on response surface method and Monte Carlo simulation

Tooth modification technique is widely used in gear industry to improve the meshing performance of gearings. However, few of the present studies on tooth modification considers the influence of inevitable random errors on gear modification effects. In order to investigate the uncertainties of tooth modification amount variations on system's dynamic behaviors of a helical planetary gears, an analytical dynamic model including tooth modification parameters is proposed to carry out a deterministic analysis on the dynamics of a helical planetary gear. The dynamic meshing forces as well as the dynamic transmission errors of the sun-planet 1 gear pair with and without tooth modifications are computed and compared to show the effectiveness of tooth modifications on gear dynamics enhancement. By using response surface method, a fitted regression model for the dynamic transmission error(DTE) fluctuations is established to quantify the relationship between modification amounts and DTE fluctuations. By shifting the inevitable random errors arousing from manufacturing and installing process to tooth modification amount variations, a statistical tooth modification model is developed and a methodology combining Monte Carlo simulation and response surface method is presented for uncertainty analysis of tooth modifications. The uncertainly analysis reveals that the system's dynamic behaviors do not obey the normal distribution rule even though the design variables are normally distributed. In addition, a deterministic modification amount will not definitely achieve an optimal result for both static and dynamic transmission error fluctuation reduction simultaneously.     

Relation between wear and tooth width modification in spur gears

In this experimental study, width modification of a spur gear was investigated to fix instantaneous pressure changes along single meshing area on the gear profile. In this gear, variable pressure distribution caused by the single and double teeth meshing and the radius of curvature along the active gear profile was approximately kept constant by maintaining a constant ratio of applied load to the tooth width (F/b) on every point. Hence, Hertz pressure distribution along the gear profile was approximately equally achieved. Other factors affecting wear were kept constant during the experiment. The specimen used was made from AISI 4140 steel. Finally, the amount of wear in the teeth profiles between the modified and unmodified gears was compared. And wear depth of modified gear along the meshing area was almost uniform.     

外齿轮内平动式新型少齿差行星传动的研究

提出了一种具有实用价值的外齿轮内平动式的新型少齿差行星传动.分析了这种行星传动的传动原理、基本结构、传动比、啮合参数和传动效率.同时,提出使用功能强大的数学软件MATHCAD确定新型少齿差行星传动变位系数的CAD方法.分析表明,这种传动能够达到系统的静平衡和动平衡,具有结构紧凑、体积小、承载能力和传动效率高、制造简单等优点,是一种很有发展前景的传动形式.     

Performance improvement method for Nylon 6 spur gears

Plastic gears made of Nylon 6 are especially susceptible to failure due to extreme heat accumulation in the single tooth mesh area, which results in damage that consequently shortens gear teeth life and causes transmission errors. In this experimental study, the teeth width of plastic spur gears made of Nylon 6 were modified and investigated. The values of load sharing, F/b, in single and double tooth meshing areas were leveled by widening the single tooth zone along the meshing area, and the performances of both modified and unmodified gears were studied experimentally under three different loadings. It was observed that modified Nylon 6 gears exhibit lower tooth temperatures, which results in a decrease in wear rate as compared to unmodified gears. Consequently, teeth width modification helps to increase Nylon 6 gear performance.