VARIABLE INERTIAL DAMPER AND ITS APPLICATION IN ZERO-DRIVE GEAR HOBBING MACHINE

A variable inertial damper, whose viscous damping coefficient can be adjusted by changing the gap between inertia wheel and motor spindle, is designed in servomechanism of zero-drive hobbing machine and is directly attached on the motor spindle. The mathematical model of servo system with inertial damper is built. By using theoretical analysis and system simulation, it is demonstrated that the variable inertial damper with optimal damping coefficient and moment of inertia should lead to no resonance point in wider frequency range of exciting force. Therefore, its application in zero-drive hobbing machine makes this system not only achieve higher system stiffness to overcome load torque fluctuation, but also gain better stability.

YKJ3180H Economy NC Gear Hobbing Machine

The YKJ3180H Economy NC GearHobbing Machine is a new variety,developed recently by the ChongqingMachine Tools Works to meet clients’demands. Its most prominent feature is its highproduction efficiency ( able to complete awork cycle automatically), high processingprecision (Grade 7 or higher according to theGB 10095) and its cost competitiveness. This product is used in the machinetool and machinery industries at automobiles,tractors, gears and gear box factories. It canbe used for processing spur gears and helicalgears, automatic radial feed wormwheels,tapered gears and crowning gears; so it isespecially applicable in factories usingcrowning gear couplings, such as metallurgy,mining, lifting transport and the chemicalmachinery.

Research and Development on NC System of Gear-hobbing Machine based on Zero-programming Technology

By the analysis of roller gear processing technology, combining with gear meshing mechanism and motion relationship, models for rolling gear machining parameter and zero-programming are established. In this paper, the automatic generation technology of NC program for CNC gear machining process has been studied and the zero-programming system architecture of open CNC gear-hobbing machine has been presented. In the design and development of the system, human computer interaction, programming algorithm and the design of each function module have bean done. Application test shows that the expected design requirements have been achieved.

Cutting Force Fluctuation Suppression and Error Homogenization of Noncircular Gear Hobbing Based on the Tool Shifting Method

The current research on noncircular hobbing mainly focuses on the linkage model and motion realization.However,the intermittent cutting characteristics of hobbing would increase uncertainties in the manufacturing process.In this paper,a hobbing machining model with tool-shifting characteristics was proposed to solve the problems of cutting force fluctuation and inconsistency of tooth profile envelope accuracy at different positions of the pitch curve in noncircular gear hobbing.Based on the unit cutting force coefficient method,the undeformed chip volume generated by interrupted cutting was used to characterize the fluctuation trend of the hobbing force.The fluctuation characteristics of the cutting force generated by different hobbing models were compared and analyzed.Using the equivalent gear tooth and hob slotting numbers,an analysis model of the tooth profile envelope error of the noncircular gear was constructed.Subsequently,the tooth profile envelope errors at different positions of the pitch curve were compared and analyzed based on the constructed model.The transmission structure of the electronic gearbox was constructed based on the proposed hobbing model,and the hobbing experiment was conducted based on the selfdeveloped noncircular gear CNC hobbing system.This paper proposes a hobbing method that can effectively suppress the fluctuation of the peak and whole circumference cutting force and reduce the maximum envelope error of the whole circumference gear teeth.

A precision generating hobbing method for face gear with assembly spherical hob

In order to improve the processing precision and shorten the hob manufacturing cycle of the face gear,a precision generating hobbing method for face gear with the assembly spherical hob is proposed.Firstly,the evolution of the cylindrical gear to spherical hob basic worm is analyzed,then the spherical hob basic worm is designed,thus the basic worm and spiral angle equation of spherical hob are obtained.Secondly,based on the design method of the existing hob,the development method of the assembly spherical hob is analyzed,the cutter tooth and the cutter substrate of the assembly hob are designed,and the whole assembly is finished.Thirdly,based on the need of face gear hobbing,a numerical control machine for gear hobbing is developed,and the equation of the face gear is obtained.Fourth,for reducing the face gear processing errors induced by equivalent installation errors,the error analysis model is established and the impacts of each error on the gear tooth surface are analyzed.Finally,the assembly spherical hob is manufactured and the gear hobbing test is completed.According to the measurement results,the processing parameters of face gear hobbing are modified,and the deviation of tooth surface is significantly reduced.

基于齿面位姿-几何误差模型的大规格滚齿机关键误差识别

为研究影响大规格滚齿机加工精度的关键几何误差,提出了一种基于齿面位姿-几何误差模型结合Sobol法的机床关键几何误差识别方法。首先,基于齐次坐标变换理论,建立了刀具位姿-几何误差模型,通过求解滚齿双参数包络方程,获得了加工齿面接触迹点坐标值,建立了机床齿面位姿-几何误差模型;然后,考虑几何误差的随机性和互耦性,利用Sobol法对该模型进行敏感性分析,计算了几何误差的敏感度系数以识别出关键几何误差;最后,进行了关键几何误差虚拟仿真修正和对比验证。研究结果表明,所提方法能有效识别大规格滚齿机的关键误差项。

滚齿机刀夹具智能选配方法的研究

在产品的生产加工过程中,刀夹具的选配对合理利用加工资源,提高加工过程中的质量和效率,降低加工成本有着十分重要的意义。为解决滚齿加工中刀夹具的选配问题,提出了一种面向滚齿机刀夹具的智能选配方法。该方法包括3个部分,即:首先,通过研究刀夹具的各项信息特征及滚齿的加工原理,并对其进行详细分析后,建立了相应的滚齿机刀夹具信息模型和选配规则;其次,基于加工原理和选配规则,确立了刀夹具的选配规则库和控制策略,并建立了初步选配流程和相应的选配模型,得到了符合加工任务的候选刀夹具集;然后,基于层次分析法与灰色关联分析法提出了一种针对该集合的刀夹具优选决策方法,完成了刀夹具优选;最后,以重庆某机床厂的齿轮加工车间为例进行案例研究,将该优化模型及选配方法应用到实际案例中以证明该选配方法的可行性,为滚齿机刀夹具的智能选配提供了理论和技术支持。

基于球形滚刀的面齿轮滚齿加工方法

面齿轮传动具有突出的优点,在航空领域具有广阔的应用前景。为提高面齿轮的加工效率,针对面齿轮球形滚刀及滚齿加工进行了研究。根据面齿轮传动原理,得到了面齿轮插齿成形的型面。研究了从圆柱齿轮向球形滚刀基蜗杆演变的过程,分析了球形滚刀的成形方法,推导了球形滚刀基蜗杆的型面方程和螺旋升角。建立了球形滚刀加工面齿轮的坐标系,推导了球形滚刀加工面齿轮的型面,利用VERICUT对2个实例进行了加工仿真,并进行了相应的实际加工试验和检测,仿真和试验结果表明球形滚刀可用于面齿轮的加工。

大型数控滚齿机立柱动力学仿真分析

为避免大型数控滚齿机滚削力引起立柱振动而影响加工精度,对大型滚齿机立柱刚度特性及谐响应进行了仿真分析。在滚齿机立柱结构特征、滚刀主轴传动原理及动力学理论基础上,建立了滚齿机立柱与滚刀箱有限元仿真模型,仿真求解得到了立柱模态及谐响应参数。通过立柱动态响应的振动频率与变形量分析,得到了滚齿机加工时立柱设计结构应避开的共振频率范围,揭示了立柱振动变形量的变化规律,提出了立柱结构设计与安装方法的改进建议,为大型数控滚齿机部件的设计优化提供了理论依据与参考。

数控滚齿机热变形误差分析与补偿新方法

为了对数控滚齿机的热变形误差进行补偿,提高齿轮加工精度,利用聚类回归分析方法,优化选择了热误差补偿过程中的温度测量点。采用最小二乘回归方法建立了热误差模型,实验结果验证,该模型精度高。提出了一种热误差差动螺旋补偿方法,该方法完全采用外部硬件补偿,能够独立地实现对热变形误差的实时补偿。与其他补偿方法对比,该方法不受限于数控系统的开放性,通用性较强。

聚类回归分析在滚齿机热误差建模中的应用

利用聚类回归分析方法的基本原理,研究了温度传感器在滚齿机上的优化布置策略,并将温度测点从原先的11个减少到4个,完成了温度变量的优选.利用优选的温度变量,采用最小二乘法进行回归建模,得到热误差模型,并利用该模型在Y3150K型滚齿机上进行热误差补偿实验.结果表明,该建模方法不但增强了热误差建模的鲁棒性,提高了齿轮加工精度,而且节省了工作量与成本.

圆弧齿线圆柱齿轮的数控滚切机理与试验研究

提出了一种利用标准齿轮滚刀滚切圆弧齿线圆柱齿轮的数控加工方法。探讨了圆弧齿线圆柱齿轮的数控滚切成形机理,推导了数控插补计算式,介绍了共轭齿轮对的制造方法。在CNC滚齿机上的实切试验表明,该工艺可获得与直齿轮同等的齿形精度与加工效率。

大型数控滚齿机热误差补偿建模

针对某大型数控滚齿机,提出滚刀与工件主轴中心距热误差计算新模型,建立热误差实验检测系统,进行热误差与温度的关系实验;在此基础上,采用模糊聚类与多元线性回归法建立滚刀与工件主轴中心距热误差补偿模型;将补偿模型与实验数据进行对比分析,揭示滚齿机热误差规律,得到热误差随加工温度变化曲线。研究结果表明:经热误差理论、实验及补偿模型值比较,三者热相对误差均低于5%,验证了所建立热误差补偿模型的正确性与有效性,表明该热误差补偿模型精度高,实用性及鲁棒性强,可为滚齿机热误差预测、控制及实时补偿提供有益参考与指导。

滚齿机热误差补偿技术研究

通过对滚齿机的热误差源进行综合分析及温度测点的优化布置,充分利用齿轮加工过程中测得的误差数据,采用最小二乘法建立了滚齿机的热误差数学模型,研制了滚齿机热误差补偿的硬件系统,利用该系统在Y3150K型滚齿机上进行了误差补偿实验,实验结果表明,实施热误差补偿后,齿轮加工精度提高2级以上,补偿效果明显。

基于自动编程系统的大型滚齿机热误差补偿

为降低大型数控滚齿机热误差,提高滚齿机加工精度,基于西门子数控系统与自动编程系统,提出一种数控滚齿机热误差补偿方法与系统。针对某型号大型数控滚齿机,利用模糊聚类法对热误差补偿温度变量进行优选,采用多元回归—最小二乘法,建立了滚齿机滚刀和工件主轴中心距热误差与温度关系的补偿模型,并在该大型数控滚齿机加工过程中进行了热误差补偿试验。结果显示,滚齿机滚刀与工件主轴中心距热误差值降低了约77.89%,齿轮加工精度提高了1～2级,表明所建立的热误差补偿模型精度高,所提出的滚齿机热误差补偿方法与系统具有实用价值。

零传动齿轮加工机床关键技术研究

突破传统的齿轮加工机床的结构设计原理,采用电主轴、DDR、DDL技术直接驱动齿轮加工机床的刀具、工作台的回转及直线进给系统,完全取消所有机械传动环节,实现动力源对机床工作部件的直接驱动,即零传动。文章就基于零传动原理对滚齿机的电主轴、DDR、DDL等关键技术作了详细分析和研究,对研究和开发我国高速、高精度零传动齿轮加工机床有重要的理论意义和实用价值。

滚齿切削力计算方法分析

针对目前国内滚削力计算方法不统一的现状,介绍和分析了国内外两种较典型的滚削力计算方法,并讨论了滚削力的影响因素及变化规律,为合理选择滚齿工艺参数提供了参考依据。

提高零传动滚齿机系统刚度的研究

高速、高精度零传动滚齿机的刀具轴和工件轴直接与电机轴连接,从而避免了齿轮组的回转误差和齿侧间隙等对回转精度和动刚性的影响。但是刀具轴或工件轴的等效转动惯量极小,使得负载转矩波动引起的回转振动很大。在伺服机构中设计一种可调式惯性阻尼器,直接附加在电机转轴上,惯性阻尼器的阻尼系数可以通过惯性轮和电机轴之间的间隙来调整。建立了附加惯性阻尼器的伺服系统的数学模型,并且通过理论分析和系统仿真,验证了可调式惯性阻尼器对于零传动滚齿机系统刚度提高的有效性。

椭圆齿轮滚齿加工三维仿真研究

为验证椭圆齿轮滚切模型的正确性,基于工具(斜)齿条原理,采用MATLAB软件进行三维仿真研究。推导了椭圆齿轮滚切数学模型,阐述了滚切仿真原理及实施方法,对直齿轮3种平面联动方式和斜齿轮2种附加运动形式分别进行三维滚切仿真。证实了椭圆齿轮滚切模型及各种滚切方法正确可行,数学处理方法对真实数控系统的开发及其他加工方法的仿真验证有借鉴价值。

大型内齿轮加工的技术现状与发展趋势

分析了现有内齿轮加工技术的特点,指出了大型内齿轮加工中存在的主要技术问题,在此基础上,展望了大型内齿轮加工技术的发展趋势,并提出,研究高精度磨齿加工技术及高效磨具以及开发经济的大型内齿轮滚切加工技术及刀具是发展大型内齿轮制造技术的两条可行的技术路线。