METHODS OF MODERN DESIGN FOR CYLINDRICAL GEAR DRIVE BASED ON THE INTERNET

The basic principle of modern design of cylindrical gear drive based on theInternet is described. The methods of optimized design, finite element analysis, CAD design and webdesign as well as research and development entity of three parties such as institute research unit(or university), enterprise and customer are also studied. Its purpose is to provide a necessaryfoundation for realizing the design of cylindrical gear drive from different location on the modemInternet and to explore a practice application route.

A NEW GENERATING METHOD FOR THE MACHINING OF A CYLINDRICAL GEAR WITH SYMMETRIC ARCUATE TOOTH TRACE

Objective To introduce a new generating method for the machining of a cylindrical gear with symmetric arcuate tooth trace. Methods Adopting this method, the key problems of mismatch control and manufacturing of symmetric arcuate tooth trace gears are solved by using suitable cutter tilt and a new generating method with double-edge gear-wheel cutter. The machining principle is analyzed and the mathematical model of generating motion is established. Then the tooth flank equation and differential geometrical parameters are discussed. Results The minim alteration of cutter tilt will make the contact flank area change so as to satisfy the special requirements. It is easy to realize the tip relief of gearing by altering coefficients of every moving axis. Because the tooth has the arc shape, the symmetrical arcuate cylindrical gears have higher overall strength and it is easy to perform the flank grinding for high precision. Conclusion This new generating method has higher productivity. It is easy to get a perfect contact zone and fully give play to the potential bearing capacity of the gears. The symmetrical arcuate cylindrical gears can be used in highly durable and heavy duty gearing applications.

A Study on Load Distribution along Contact Lines of Cylindrical Involute Gears

The mathematical model of current methods for determining load distribution along contact lines of the instantaneously engaged teeth of gears has a defect that its numerical solution is not unique. In order to overcome this defect, a new method based on three-dimensional finite element compliance matrix method improved by smoothing method is presented. Calculated examples of helical gears show that the new method can calculate tooth load distribution accurately and agree well with the results of experiments.

Simulation study on dynamics of cylindrical gear meshing with the evolution meshing stiffness

Simulation study on the cylindrical gear meshing with the evolution gear meshing stiffness is being done for better understanding the dynamic characteristics of the kinematics.With consideration of damping,bearing clearance and gear backlash nonlinearity,the dynamic model is set up and computed in MATLAB.The analysis about the relationship between the kinematic responses and the meshing stiffness are carried out.And the results showed that as the gear mesh stiffness is changed from small to large,the performance of the system is changed from the harmonic stable periodic motion to with one times,two times,four times,ending chaos of the stability of the bifurcation.The research results would have theoretical guidance value for the fault diagnosis in engineering.

STUDY ON CONTROLLABLE MISMAT－CHED ENGAGEMENT OF CONE－GEN－ERATED CYLINDRIC WORM GEARING

Controllable modification of cone-generated cylindric worm gearing has been carriedout. The tooth contact state of modified gearing can be controlled by selecting the positions of con-tact points of worm surfaee and the correction amount of curvature. The modification machiningcan be conveniently implemented by changing the geometrical sizes and setting parameters of grind-ing wheel. Therefore the research has better scientific basis and practical value.

可实现连续分度加工的摆线圆柱齿轮研究

研究了一种可采用连续分度铣削法进行加工的摆线圆柱齿轮。与传统的圆柱齿轮不同,这种齿轮的轮齿沿其轴线方向呈摆线形。该齿轮具有承载能力大、传动平稳、无轴向力等特点;尤其是可采用连续铣削的加工方法,大大提高加工效率。摆线圆柱齿轮可采用圆盘铣刀加工,圆盘铣刀上装有可更换的刀片,同一模数的齿轮只需要一把盘铣刀,通过更换刀片可进行不同模数齿轮的加工。首先,基于齿轮啮合理论推导了摆线圆柱齿轮的数学模型,利用自行开发的计算软件生成离散齿面点,建立三维模型;然后,阐述了圆盘铣刀的几何设计和齿轮的加工原理;最后,从齿轮特性、加工效率和标准化生产3个方面说明了该齿轮的优势。研究为圆柱齿轮的设计和加工提供了新的思路和基础。

蜗杆-斜齿轮传动齿面啮合干涉分析

蜗杆-斜齿轮传动具有传动比大、传动平稳等优点,广泛应用于各种小型交错轴传动。与蜗杆完全共轭的理论斜齿轮与常规的标准斜齿轮存在齿形差异,因此蜗杆和标准斜齿轮传动存在齿面间的啮合干涉,会影响传动性能。基于螺旋面圆柱蜗杆与斜齿轮的双参数包络成形原理,建立了阿基米德蜗杆和齿槽法向直廓蜗杆与斜齿轮的啮合方程,推导了理论共轭斜齿轮齿面,并与实际标准斜齿轮齿面比较,分析了传动过程中齿面接触干涉区域和干涉量。分析结果表明,蜗杆头数和节圆半径对蜗杆齿轮传动的啮合干涉有影响,增加蜗杆头数、减小蜗杆节圆半径都会使干涉量增加;在相同的蜗杆设计参数条件下,齿槽法向直廓蜗杆的干涉量要大于阿基米德蜗杆,以上结论为蜗杆斜齿轮传动的设计提供了参考依据。

渐开线圆柱齿轮接触分析计算与仿真研究

为方便实现渐开线圆柱齿轮接触分析,开发出渐开线圆柱齿轮啮合接触分析和齿廓修形算法程序.采用渐开线直齿轮参数方程精准建模,获得齿廓接触点的曲率半径,在考虑实际载荷的情况下,改进了赫兹接触公式来求解齿轮啮合接触应力.为减缓齿轮啮合冲击,在算法程序中提供了5种齿廓修形方式及其修形后的接触应力分析方法.与行业公认的齿轮设计仿真软件MASTA计算结果进行对比.结果表明,该算法程序接触应力求解精度较高,相对MASTA平均误差约为5.04%,齿廓修形后的接触应力分布一致,验证了该算法程序的合理性.

航空圆柱直齿轮热摆辗成形工艺分析

为研究航空圆柱直齿轮热摆辗成形过程中金属变形规律和齿形充填特点,利用DEFORM-3D软件建立了圆柱直齿轮热摆辗成形三维刚塑性有限元模型,模拟了其热摆辗成形过程。结果表明,圆柱直齿轮热摆辗成形过程中,坯料变形区分为主动变形区和被动变形区,并随着摆头的运动而呈周期性变化;随着变形的进行,主动变形区金属流动方向从径向转变为轴向充填模具型腔,齿形从上端到下端逐渐成形,坯料呈蘑菇状;齿根区域等效应变与等效应力值最大,齿顶温度高于齿根温度;轴向载荷随塑性变形的进行逐渐增大,最大值约为2500 kN,径向载荷呈周期性变化,径向载荷远小于轴向载荷。开展了圆柱直齿轮热摆辗工艺实验,实验结果与模拟结果吻合。

考虑弹性误差的渐开线圆柱齿轮半解析接触模型与传动精度分析

在弹性和误差作用下,齿轮接触的高效、精准建模是研究齿轮传动精度的重要基础。为准确分析渐开线圆柱齿轮的弹性和误差对传动精度的影响,提出了一种考虑弹性误差的齿轮半解析接触模型。以渐开线斜齿圆柱齿轮为例,首先,结合齿轮的齿面方程与齿廓误差建立误差齿面模型,得到了误差齿面方程。然后,将解析法和有限元法相结合,建立了弹性误差作用下的齿轮半解析接触模型,并推导了其变形协调方程和力平衡方程。最后,建立齿轮的完整和局部有限元模型,通过提取接触齿面的柔度矩阵来计算齿轮的传动误差。应用所构建的半解析模型分析了齿廓误差和弹性变形对齿轮传动精度的影响规律,并与有限元仿真结果进行对比,验证了该半解析模型的高效性和精准性。研究结果可为渐开线圆柱齿轮在工程中的应用提供理论指导。

基于旋分法圆柱齿轮端面倒棱方法研究

基于生产中圆柱齿轮倒棱的高效率和高经济性等需求,结合旋分加工原理和特点,文章提出了一种基于旋分法端面的倒棱方法。首先,结合旋分加工原理,分析旋分倒棱加工运动,建立齿轮和刀具的运动坐标系,并推导坐标系之间的变换关系;其次,根据选定的初始切削刃和建立的坐标变换关系,在齿轮坐标系中构建初始刃扫面;再次,根据刀具设计原理和刃扫面,构建前刀面得到切削刃和构建后刀面,并建立刀具的三维模型;最后,通过多轴数控加工仿真平台开展了齿轮端面旋分倒棱仿真实验。实验结果表明,使用该方法配合所设计的倒棱刀能够实现齿轮端面齿廓高效倒棱需求。

新型平面螺旋齿线圆柱齿轮及其加工方法

为提升圆柱齿轮的加工效率与齿轮副承载能力,提出了一种新型的平面螺旋齿线圆柱齿轮与该齿轮的快速成形方法,即采用旋转大刀盘快速铣削齿轮,刀盘上按平面螺旋线(阿基米德螺旋线)布置多个刀杆与刀具连续切削齿轮齿槽,平面螺旋线螺距与被加工齿轮齿距相等,刀盘旋转一圈,被加工齿轮旋转一个齿,实现对齿轮的连续快速加工,通过VERICUT加工仿真验证了该方法的可行性;并研制专用加工机床,实施新型齿轮的加工;阐明了加工出的平面螺旋齿线圆柱齿轮的主要参数,其凹齿面齿线半径略大于凸齿面齿线半径,轮齿呈微鼓形,可以减弱齿轮副啮合偏载。通过对平面螺旋齿线圆柱齿轮副进行三维模拟啮合分析,得出平面螺旋齿线圆柱齿轮副接触区间主要分布于接触齿面中间的部分区域,且轮齿两端受力逐渐变小,有效减少了轮齿两端齿根处的弯曲应力,提升了齿轮副承载能力。

基于智能算法的齿轮副传动优化设计

为对两级渐开线圆柱齿轮减速器的齿轮结构进行优化设计,根据齿轮强度计算标准和机械结构优化设计的相关理论,分析了对齿轮接触强度和弯曲强度较大有影响的参数,以最小中心距为目标函数,以齿轮强度、尺寸等为约束条件,建立了两级渐开线圆柱齿轮传动结构优化的数学模型。基于智能算法(遗传算法)对齿数、模数、螺旋角等参数进行多目标优化,优化后齿轮的最小中心距减少了28.99%,有效的提高了空间利用率。同时该文研究结果可为智能设计、智能制造提供参考。

利用齿面接触印痕逆向确定曲线圆弧齿轮的加工刀盘半径

为了设计出任意齿面接触印痕的曲线圆柱齿轮副,提出了一种根据所需齿面接触印痕尺寸逆向确定加工曲线圆柱齿轮的盘形铣刀半径的方法。首先,介绍了曲线圆柱齿轮副的齿面数学模型;其次,建立了齿面接触印痕计算的数学模型;然后,以4种不同半径的双刃铣刀所加工的曲线圆柱齿轮为例,研究了盘形铣刀半径与齿面接触印痕之间的关系图谱;最后,利用插值法实现盘形铣刀半径的选择。该法可以跳过齿轮的试加工环节,降低了齿轮制造成本,为固定面铣式曲线圆柱齿轮的设计与制造奠定了基础。

渐开线圆柱齿轮的通用型滚插刀设计方法

针对渐开线圆柱齿轮的滚插加工,基于交错轴渐开螺旋面线接触啮合,提出一种通用型滚插刀设计方法,适用于任意结构前刀面。简述滚插加工原理,分析计算交错轴渐开螺旋面线接触啮合的条件;从渐开螺旋面出发,给出切削刃的计算方法,以重磨后刃形精度不变为要求,构建后刀面模型;分析并给出了滚插加工参数的计算方法;基于滚插刀设计实例和VERICUT软件对不同参数的工件进行仿真加工,验证了所设计滚插刀的通用性与可行性,为通用型滚插刀设计提供了一种简单、无刃形误差的方法。

多模数ZI蜗杆斜齿轮传动设计与有限元分析及其应力预测

为解决传统渐开线蜗杆斜齿轮副在开式传动或传动比过大时斜齿轮容易发生齿根断裂的情况,提出一种新型的基于不等模数不等压力角设计的渐开线蜗杆副,使斜齿轮的模数与压力角同时提高,大幅提高斜齿轮的齿根强度。通过对此种蜗杆副的传动特性的分析,得到特殊的啮合角与中心距计算方式。另外,通过对同传动比、同蜗杆情况下基于不等模数设计的ZI蜗杆斜齿轮副和传统ZI蜗杆斜齿轮副的建模与有限元分析,得出在较大模数比情况下的斜齿轮齿根强度约为传统斜齿轮齿根强度的2.956倍,增大了渐开线蜗杆的应用范围。后续使用灰色预测,对比出误差平方和(Sum of Squared Errors,SSE)最小模型,予以验证预测的准确性,另外进行蜗杆施加不同转矩下的斜齿轮啮合齿受拉力处最大应力σ_(1max)的数据预测,为相应的工程分析与必要的校核设计给出了依据。

变双曲圆弧齿线圆柱齿轮功率损失研究

齿轮在实际运行时的功率损失是影响其传动效率的重要因素。结合流体力学理论,根据变双曲圆弧齿线(VH-CATT)圆柱齿轮结构及传动特点,建立以FZG齿轮箱为参照的三维模型,采用光滑粒子流体动力学(SPH)方法对气-液两相流下VH-CATT圆柱齿轮功率损失进行仿真分析。得到了气液两相流作用下齿轮箱内部润滑油与空气的流场及速度场,研究不同转速、不同润滑油、不同浸油深度对VH-CATT圆柱齿轮的功率损失的影响机理,并通过FZG试验台对仿真结果进行验证。研究结果表明:转速越高齿轮功率损失也越大;高黏度的润滑油具有更强的拖曳能力,使得齿轮功率损失更大;功率损失受浸油深度的影响呈正相关,选取适当的润滑油液位可以使得齿轮获得更好的润滑效果,产生较小的功率损失。

Mathematical Model and Machining Method for Spiral Flute Rake Faces of Hourglass Worm Gear Hob

To improve the cutting performance of an hourglass worm gear hob and the accuracy of the resulting worm gear,the rake angles of the teeth on the pitch circle should be reduced.A method of forming the spiral flutes by using a variable transmission ratio was developed.This method ensures that the rake angles on the indexing torus of each tooth are approximately 0°.Based on the gear meshing theory and the hourglass worm forming method,the discretization mathematical model of the rake face of a planar double enveloping worm gear hob was established by using cylindrical generating surface,and the feed parameters for machining the rake face for a variable transmission ratio were obtained.The spiral flute was simulated and the hob was machined on a four axis CNC milling machine.A contourgraph was used to measure the rake angle.The measurement results showed that the proposed method can reduce the absolute value of the rake angle on both sides of the cutting teeth,which can be used for machining the spiral flute rake face of an hourglass worm gear hob.

Effect of nonlinear impact damping with non-integer compliance exponent on gear dynamic characteristics

A nonlinear impact damping model of single-degree-of-freedom spur cylindrical gear with backlash and time-varying stiffness was established. Systematic analyses of the dynamic responses were performed. First, the nonlinear damping coefficient was considered as a constant parameter with two types of compliance exponent, meanwhile, dynamic factors were adopted to depict the dynamic characteristics. Second, the bifurcation graphs were plotted, where the damping coefficient was obtained along with the impact velocity and coefficient of restitution. The results show that light and heavy load conditions have an effect on the responses when the compliance exponent is integer. On the contrary, when the compliance exponent is non-integer, the dynamic responses are slightly affected, namely the system is more stable than the former situation.

Investigation of the Effects of Profile Shift in Helical Gear Mechanisms with Analytical and Numerical Methods

In this paper, the effects of profile shift in cylindrical helical gear mechanisms have been investigated with numerical and analytical calculations. The mathematical model for computer simulation of gears has been designed and the numerical calculations have been carried out. Analytical calculations have been made with an excel program which was designed at different profile shift coefficients for a selected mechanism. Analytical calculations of the same mechanism have been verified by using ANSYS 14.5. The results of analytical and numerical solutions have been compared to profile shift coefficients.