Active Design Method of Tooth Profiles for Cycloid Drive Based on Meshing Efficiency

An active design method of tooth profiles for cycloid gears based on their meshing efficiency is proposed.This method takes the meshing efficiency as one of the design variables to determine the tooth profiles.The calculation method for the meshing efficiency of planetary transmission is analyzed and the equation of the meshing efficiency is deduced.Relationships between the meshing efficiency,the radius of the pin wheel and the eccentric distance are revealed.The design constraint quations and the strength constraint quations are deduced.On the basis of this,a design procedure is laid out.Some examples using different input parameters are conducted to demonstrate the feasibility of the approach.A dynamic simulation of the rigid flexible coupling of cycloid gears is also presented.The results show that the proposed design method is more flexible to control the tooth profiles by changing the input values of the transmission efficiency.

MESHING THEORY AND DESIGN METHOD OF NEW SILENT CHAIN AND SPROCKET

Based on the study of the meshing theory of a new silent chain and sprockets, and the rolling cutting theory of sprocket and hob, the harmonious relations of dominating dimensions among the new silent chain, sprocket and hob is build, the meshing conditions are expatiated, and the resolved expression, which can instruct design and calculation, is educed. The tests show that the meshing design method is feasible.

Quasi Ellipsoid Gear Surface Reconstruction Based on Meshless Local Petrov-Galerkin Method and Transmission Characteristic

Special transmission 3D model simulation must be based on surface discretization and reconstruction, but special transmission usually has complicated tooth shape and movement, so present software can＇t provide technical support for special transmission 3D model simulation. Currently, theoretical calculation and experimental method are difficult to exactly solve special transmission contact analysis problem. How to reduce calculation and computer memories consume and meet calculation precision is key to resolve special transmission contact analysis problem. According to 3D model simulation and surface reconstruction of quasi ellipsoid gear is difficulty, this paper employes meshless local Petrov-Galerkin （MLPG） method. In order to reduce calculation and computer memories consume, we disperse tooth mesh into finite points--sparseness points cloud or grid mesh, and then we do interpolation reconstruction in some necessary place of the 3D surface model during analysis. Moving least square method （MLSM） is employed for tooth mesh interpolation reconstruction, there are some advantages to do interpolation by means of MLSM, such as high precision, good flexibility and no require of tooth mesh discretization into units. We input the quasi ellipsoid gear reconstruction model into simulation software, we complete tooth meshing simulation. Simulation transmission ratio during meshing period was obtained, compared with theoretical transmission ratio, the result inosculate preferably. The method using curve reconstruction realizes surface reconstruction, reduce simulation calculation enormously, so special gears simulation can be realized by minitype computer. The method provides a novel solution for special transmission 3D model simulation analysis and contact analysis.

PROPER CONDITIONS OF MESHING FOR Hy-Vo SILENT CHAIN AND SPROCKET

Proper meshing of Hy-Vo silent chain and sprocket is important for realizing the transmission of the silent chain with more efficiency and less noise. Based on the study of the meshing theory of the Hy-Vo silent chain with the sprocket and the roll cutting machining principle of the sprocket with the hob, the proper conditions of the meshing for the Hy-Vo silent chain and the sprocket are put forward with the variable pitch characteristic of the Hy-Vo silent chain taken into consideration, and the proper meshing design method on the condition that the value of the link tooth pressure angle is unequal to the value of the sprocket tooth pressure angle is studied. Experiments show that this new design method is feasible. In addition, the design of the pitch, the sprocket tooth pressure angle and the fillet radius of the sprocket addendum circle are studied. It is crucial for guiding the design of the hob which cuts the Hy-Vo silent chain sprocket.

Influence Predictions of Contact Effects on Mesh Stiffness of Face Gear Drives with Spur Gear

Mesh stiffness is one of important base parameters of face gear dynamic studies.However,a calculation solution of mesh stiffness of face gear drives is not to be constructed due to complex geometric flakes of face gear teeth.Thus,a calculation solution of mesh stiffness of face gear drives with a spur gear,which is based on the proposed equivalent face gear teeth and Ishikawa model,is constructed,and the influence of contact effects on mesh stiffness of face gear drives is investigated.The results indicate the mesh stiffness of face gear drives is sensitive to contact effects under heavy loaded operating conditions,specially.These contributions will benefit to improve dynamic studies of face gear drives.

安装误差对双圆弧齿轮啮合特性影响分析

为深入研究安装误差对双圆弧齿轮副啮合特性的影响,基于有限元法建立齿轮加载分析模型,研究啮合过程中单齿凸、凹齿廓的接触性能,对比分析安装误差对接触性能以及传动误差的影响规律。结果表明:啮合周期内,双圆弧齿轮的凹齿廓先接触且承担较大的法向接触力,但凸齿廓的啮入端接触应力最大,凸、凹齿面接触压力差与转矩成正比;安装误差对齿面接触性能影响较大,其中中心距误差容易引起齿轮分阶处应力集中,轴线平面的安装误差会引起齿面接触偏载,且对安装误差影响最大。

考虑齿面剥落的齿轮传动系统动力学建模

针对现有能量法无法准确描述齿轮存在齿面剥落的时变啮合刚度,造成齿轮传动系统故障的动力学建模方法不完善的问题,提出改进能量法。考虑不同类型的齿面剥落,建立一种考虑齿面剥落的时变啮合刚度公式。将所建立的齿面剥落时变啮合刚度公式引入六自由度传动系统,建立一个能够模拟齿面剥落的齿轮传动系统动力学模型。采用Newmark-β法进行求解,将数值模拟结果与试验数据进行对比分析,验证了所建立模型的准确性。基于该模型分析了不同齿面剥落关键参数对时变刚度的影响和对应的刚度变化规律及动力学响应的频率特性规律。研究结果表明,考虑齿面剥落的齿轮传动系统特征频率左右两侧会出现间距10Hz的次生频率峰值。

考虑齿形误差影响的摆线针轮承载特性分析

针对缺乏考虑齿形误差的承载分析软件,导致分析结果不符合实际工程状况的问题,提出了1种包含摆线轮齿形误差的摆线针轮副承载特性分析方法。利用三次非均匀B样条准确描述出包含齿形误差的摆线轮实际齿廓,构建并分析了摆线针轮误差齿廓接触分析模型(error tooth contact analysis,E-TCA),得到了初始啮合位置参数及啮合间隙。在此基础上,建立了齿形误差影响下的摆线针轮副负载接触分析模型,确定了零部件多体接触之间的力矩平衡和变形协调关系,利用能量最低原理获取了真实承载特性。通过有限元模型验证了RV-40E型号减速器的摆线针轮承载特性。结果表明:由于齿形误差的影响,啮合齿数减少了1对,啮合应力和传动误差增大了5.3%和5.7%。

非圆齿扇齿条副齿面接触应力分析及仿真

针对汽车转向器摇臂轴非圆齿扇的工作齿面易发生磨损、点蚀甚至断裂等现象,围绕非圆齿扇齿条副的齿面接触应力理论建模与有限元仿真分析开展研究,提出一种非圆齿扇齿条副接触应力理论计算模型,研究齿扇齿宽B、齿条压力角α和齿扇锥角φ等几何参数对齿面接触应力的影响规律;将非圆齿扇齿条副三维参数化建模与齿面动态啮合有限元仿真分析集成,提出一种非圆齿扇齿条副接触应力参数化、全流程仿真分析计算方法。预期为汽车转向器非圆齿扇齿条副的设计分析提供理论和方法指导。

同向全啮合双螺杆植物蛋白挤出机不同螺杆元件的仿真分析

为了明确和量化同向全啮合双螺杆挤出机各螺杆元件的功能,增加配置用于生产植物基肉双螺杆挤出机螺杆的合理性,以低温脱脂花生蛋白粉的物性参数为条件,对SLZ36型挤出机的3种元件长度为32 mm的螺杆元件双头螺旋元件、5啮合盘啮合元件及3齿形盘齿形元件的剪切速率、混合指数、物料停留时间、最大剪切应力分布进行仿真分析。采用Solidworks软件建立元件的几何模型,应用Gambit软件进行模型的网格划分及网格质量分析,在Polyflow软件中进行数值模拟,通过Fieldview软件对仿真结果进行后处理分析。结果表明:通过混合指数分析得到3种螺杆元件对物料的混合性能大小为齿形元件>啮合元件>螺旋元件;通过物料停留时间分析得到3种螺杆元件的轴向混合性能大小为齿形元件>螺旋元件>啮合元件;通过剪切速率及平均最大剪切应力分析得到对物料的剪切性能大小为啮合元件>螺旋元件>齿形元件。进行植物基肉双螺杆挤出机螺杆组合时,针对目前整个螺杆配置螺旋元件最多的情况,在进行物料更换时可以合理地配置啮合元件以增加螺杆剪切能力,配置齿形元件以增加螺杆的混合能力。

考虑齿面闪温的风电齿轮箱裂纹故障特征分析

为了研究齿面闪温对风电齿轮箱裂纹故障时系统动力学响应的影响,利用Blok闪温理论分析齿轮啮合时的齿面温度,应用热变形公式计算齿廓形变,进而通过Hertz接触理论获得计及齿面闪温影响的轮齿刚度。考虑齿面闪温、阻尼、时变啮合刚度、综合啮合误差和齿侧间隙,建立含有高速级齿轮齿根裂纹的齿轮箱扭转动力学模型。通过时域图、频谱图、相图和Poincaré截面分析不同裂纹长度下系统振动特性随齿面闪温变化的规律,并比较裂纹故障仿真与实验的时频域结果。结果表明:齿面闪温使时域图上裂纹产生的冲击幅值增大、频域图中故障边频结构更为复杂、相图曲线向外扩展以及Poincaré截面离散点增多,且变化均随裂纹长度的增加越为明显。研究结论可为齿轮裂纹故障状态的诊断与监测提供依据。

等距螺旋锥齿轮的精确建模与金属粉末注射成型工艺试制

等距螺旋锥齿轮作为一种新型锥齿轮,其螺旋齿面具有法向等距的特点,适用于金属粉末注射成型工艺批量化生产。根据坐标变换理论推导出球面渐开线和等距圆锥螺旋线的参数方程,再基于齿面形成原理建立齿面数学模型;在MATLAB中对齿面数学模型编程计算出齿面离散点坐标,并通过UG逆向工程完成等距螺旋锥齿轮的精确建模;利用ANSYS仿真分析等距螺旋锥齿轮的啮合接触,得出齿轮的传动性能;最后通过金属粉末注射成型工艺完成等距螺旋锥齿轮的试制。研究结果表明,齿面数学模型结合离散点逆向建模可确保模型的精度,金属粉末注射成型工艺可用于等距螺旋锥齿轮的批量化生产。

Dynamics of a Dual Power-split Transmission Based on Loaded Tooth Contact Analysis

In order to implement the dynamic characteristic of a dual power-split transmission, a dynamic me- chanics model is built. Firstly, according to the method of theoretical analysis of the tooth contact analysis （TCA） and loaded tooth contact analysis （LTCA）, the actual meshing process of each gear pairs is simulated, and the time-varying mesh stiffness excitations are obtained, which can improve the numerical precision. Second- ly, by using the lumped mass method, the bending-torsional coupling three dimensional dynamic model of the dual power-split transmission is established, and the identical dimensionless equations are deduced by elimina- ting the effect of rigid displacement and the method of dimensional normalization. Finally, by the method of the fourth order Runge-Kutta algorithm with variable step lengths, the responses of this system in a frequency domain and time domain are obtained, and the dynamic load change characteristics of each gear pairs are analyzed. The results show that the establishment, solution and analysis of the system dynamics model could provide a basis for the dynamic design, and have an important significance for the dynamic efficiency analysis and dynamic perform- ance optimization design of the dual power-split transmission.

双摆线针齿传动的齿廓特性与啮合特性分析

为了解决传统的摆线针齿传动输出结构易损坏、结构复杂等问题,将内、外摆线齿廓运用到NN型少齿差行星齿轮传动领域,提出了一种新型的摆线针排齿轮,并进行了其齿廓特性和啮合特性分析。对摆线轮的齿廓方程、压力角进行公式推导,分析了齿廓参数对压力角的影响,为该新型传动系统的应用奠定基础;对不同齿廓修形方法下的内外摆线齿轮进行参数方程推导,并利用Matlab软件进行仿真分析,以解决由于润滑黏膜、制造误差等一系列原因所产生的啮合间隙问题;最后,对双摆线针齿传动进行力学特性分析,为后续的减速器设计和有限元分析提供了理论基础。研究对开发新的传动方式具有意义和工程使用价值。

双重螺旋法准双曲面齿轮啮合性能研究

针对采用双重螺旋法(全工序法)加工的准双曲面齿轮副,运用数值分析的方法研究了安装误差、螺旋运动系数与啮合性能之间的作用规律。利用矢量法建立切齿加工数学模型,求得齿面方程并建立齿轮副装配数学模型,利用齿面接触分析(TCA)研究含多种安装误差的齿面接触特征;建立齿面失配数学模型,分析螺旋运动系数对齿面接触特征、几何形貌的影响规律,揭示双重螺旋法对轮齿工作面、非工作面不同的修形原理;结合刀具与齿坯之间的相对位置关系,阐述了展成线的求解过程,研究了螺旋运动系数对展成线位置的影响规律。对准双曲面齿轮副(7×43)进行磨齿和滚检实验,与数值分析结果进行对比验证了分析模型的正确性。

正交直齿面齿轮车齿刀具精确设计方法

为提高正交直齿面齿轮的加工精度,提出了一种针对正交直齿面齿轮的车齿刀具精确设计方法。基于齿轮交错轴啮合原理,对面齿轮的车齿加工过程进行解析;通过与面齿轮啮合的圆柱齿轮渐开线齿廓,包络出车齿刀齿面方程;基于法向平面,设计了刀具结构并推导了刀具切削刃表达式;求解切削刃与面齿轮的啮合条件式,推导数控加工规律并对面齿轮齿面进行了理论计算与仿真加工;将结果与面齿轮理论齿面进行了数值对比。结果表明,当刀具不存在误差时,可以得到面齿轮理论齿面;通过Vericut仿真,齿面误差保持在10 μm以内。

裂纹工况下斜齿轮系统啮合刚度计算模型研究

当斜齿轮副产生裂纹时,会影响齿轮副的啮合刚度。为了获得更准确的裂纹斜齿轮副的啮合刚度,提出一种改进的裂纹斜齿轮啮合刚度计算模型,综合考虑轮齿刚度、齿轮基础刚度在横向和轴向的影响,研究了齿顶扩展裂纹和端面扩展裂纹两种典型裂纹工况下的齿轮系统啮合刚度,并将啮合刚度解析计算结果与有限元模拟结果进行了对比。结果表明:啮合刚度的降低程度主要与裂纹区域有关,裂纹区域越大,啮合刚度降低越大;在裂缝长度和深度相同的情况下,端面扩展裂纹对啮合刚度的影响比顶部扩展裂纹更显著。仿真结果与计算结果吻合较好,验证了所提方法的准确性和有效性。

含有不同裂纹类型的弧齿锥齿轮副啮合特性分析

在重载和交变载荷工况下,弧齿锥齿轮易产生齿根裂纹导致轮齿断裂,需明晰裂纹对啮合特性的影响机理,为故障诊断提供理论基础.利用ANSYS软件对弧齿锥齿轮齿副进行静态接触仿真分析.通过单元节点替换的方法设置了多种裂纹类型的故障模型,探讨了裂纹对弧齿锥齿轮副啮合特性的影响.研究结果表明:当轮齿接触椭圆移动到轮齿裂纹区域,啮合刚度随着裂纹的严重程度增加而逐渐下降,平面裂纹工况、空间裂纹工况和断齿工况的刚度最大下降量分别为27.58%,14.12%,32.82%.轮齿啮合的接触椭圆位置、裂纹位置以及深度会使齿面接触应力以及齿根弯曲应力产生不同的增减趋势.

驱动桥摆线准双曲面齿轮啮合效率优化设计

基于齿轮摩擦加载接触分析(FLTCA)方法,提出了摆线准双曲面齿轮啮合效率优化设计方法。首先,通过预设空载传动误差峰峰值和接触区位置,实现了对摆线准双曲面齿轮正、反车齿面的修形设计。然后基于修形面设计,以行驶工况下齿轮啮合效率最大为优化目标,并综合考虑齿轮副加载传动误差峰峰值、双侧齿面满载接触印迹分布以及最大接触应力建立了优化分析模型。为了提高优化模型的求解速度,采用Kriging代理模型结合多岛遗传算法对优化模型进行了求解。最后,对某型号商用驱动桥摆线准双曲面齿轮副进行了实例设计和试验验证,通过空载接触印迹试验和整桥传动效率试验验证了所提优化方法的有效性。

裂纹故障下细高齿齿轮齿根动应变研究

为探究裂纹故障对细高齿齿轮齿根动应变的影响规律,采用集中质量法建立齿轮系统动力学模型,将故障下的时变啮合刚度作为输入,对系统动力学方程进行求解得到不同裂纹深度下的齿轮副动态啮合力。利用有限元法建立含裂纹故障齿轮结构动力学分析模型,结合轮齿承载接触分析确定裂纹故障下的齿间载荷分配关系,采用瞬态分析得到齿根应变时域历程,并对不同裂纹深度下的齿根动应变进行分析。仿真结果表明,当从动轮发生裂纹故障后,其齿根动应变故障特征主要表现为啮合区内齿根应变数值的变化,主动轮齿根动应变故障特征主要表现为齿根应变时域历程中出现周期性冲击及幅值衰减,在1.5 mm裂纹深度下主动轮齿根应变峰值因子相对变化量达到12.72%。