Analysis of the influence of gear dimensions on cutting speed and contact conditions during the gear honing process

In many cases, gear honing represents a cost-efficient process for gear manufacturers. Another advantage of gear honing is the generation of a surface structure on the tooth flank which improves the noise behavior of the gear. Previous research activities have resulted in reliable gear honing processes, particularly for automotive gears with a tip diameter of up to 150 mm. Problems occur, however, when honing larger gears with a tip diameter of more than 150 mm, thereby rendering a robust manufacturing process is difficult. In the course of this paper, an analysis will be carried out of the geometrical and kinematic conditions that will lead to a better understanding of the process. The aim of this report is to provide an overview of the current basic conditions of the gear honing process. Theoretical studies are conducted to identify differences in gear honing processes with various tip diameters. This analysis forms the basis for optimizing process design, with the aim of generating a cost-efficient gear honing operation for gears with a tip diameter of more than 150 mm.     

齿轮式金刚石修整轮在外啮合珩齿新工艺中的应用

外啮合珩齿工艺是一种效率高、成本低的硬齿面齿轮加工工艺,但对齿轮精度的提高有限。本文采用自制的金刚石修整滚轮在Y4632A外啮合珩齿机上对外啮合珩磨轮进行修形,明显提高了外啮合珩齿的加工精度,使外啮合珩齿有可能应用于硬齿面齿轮精加工。在此基础上,进一步提出了用金刚石修整轮代替珩磨轮直接珩齿的新工艺,试验证明,新工艺省去了珩磨轮的制作和修形过程,进～步提高了加工效率和加工精度,操作容易,加工成本不高,直接使用外啮合珩齿机,相对于设备价格昂贵的内啮合珩齿机和磨齿机,节约了大量设备投资,适于中小企业生产,是一种切实可行的硬齿面齿轮精加工方法。     

齿轮式金刚石修整滚轮在齿轮精加工中的应用研究

齿轮式金刚石修整滚轮是多种齿轮精加工工艺的修整工具，本文探讨了它的制作方法和注意事项，并用自制的金刚石修整滚轮在内啮合珩齿机、蜗杆砂轮磨齿机上对内珩轮、蜗杆砂轮进行了修磨，试验证明，自制的金刚石修整滚轮精度完全符合使用要求。     

外啮合珩齿珩轮修形新方法

外啮合珩齿是硬齿面齿轮加工的重要方法，本文分析了用齿轮式的金刚石修整滚轮对外珩磨轮进行修形的机理，并用自制的金刚石修形轮在Y4632A外啮合珩齿机上进行了修形及加工试验。     

Chip geometry and cutting forces in gear power skiving

This paper describes a new virtual model for predicting the uncut chip geometry and cutting forces in power skiving, which is a high-speed, versatile gear cutting process. The developed kinematic model is applied in a dexel-based solid modeling engine to extract three-dimensional uncut chip geometry, from which the two-dimensional cross section is obtained via Delaunay triangulation. Cutting velocities along discretized cutter edges are calculated and used to determine the effective rake and oblique angles. Then, force predictions are made using the oblique cutting model and validated using measurements from power skiving trials performed on a DMG MORI NT5400DCG mill-turn machine.     

Critical review of electrochemical honing: sustainable and alternative gear finishing process. Part 2: effects of various process parameters on surface characteristics and material removal rate

Part 1 of this review discussed conventional gear surface finishing processes and their advantages and limitations, and introduced the electrochemical honing (ECH) process (and its extension of pulsed electrochemical honing (PECH)), to improve the surface characteristics of different types of gears, working principles, mechanism of material removal and equipment details. Part 2 gives a review of past work, and discusses effects of various process parameters on surface characteristics and finishing productivity (i.e. material removal rate), advantages and limitations, and its other applications. The objective of this review paper is to present ECH/PECH as one emerging alternative, economical, productive and sustainable gear finishing process.     

Gear finishing by abrasive processes

Based on the position of hard finishing in the process chain of gear manufacturing, the dominant processes with a geometrically non-defined cutting edge are analysed. While processes like continuous profile grinding and discontinuous generating grinding with double cone discs became less important in the last couple of years, the processes continuous generating gear grinding, discontinuous profile grinding and honing of tooth flanks gain rising importance. The analyses of the processes include functionality, the development status, respectively, maturity as well as identifiable trends. Process superior aspects like dressing of the grinding wheel and honing rings and the problem of grinding burn will be considered and evaluated separately.     

压杆效应对齿轮增减速传动振动的影响

从产生齿轮传动振动的根源--力出发.对造成齿轮增速传动与减速传动振动差异的原因进行了分析.通过对齿面摩擦力形成的压杆效应指数计算公式的推导,揭示了压杆效应指数与齿轮传动振动之间的关系,同时还给出了齿轮传动增速与减速振动相对强弱的判别公式,通过模型试验得到了与理论分析基本一致的结果.     

超声振动珩磨表面残余应力数值模拟研究

目的磨削产生的残余应力对工件表面特性有重要影响,超声振动珩磨使磨粒具有极大的加速度而改变了材料去除机理,研究超声振动对工件表面残余应力的影响及产生机理。方法分析残余应力形成有限元理论,建立基于热弹塑性有限元法的超声振动单颗CBN磨粒切削40Cr Ni Mo A热力耦合有限元模型,并设置两次切削、卸载、约束转换及冷却等分析步。通过数值模拟得到不同振动参数下表面残余应力的分布情况,并对模拟结果进行分析。结果有限元计算得到的各分析阶段应力分布存在差别,超声振动参数设置达到仿真要求;对磨粒施加超声振动后珩磨力下降约26%,珩磨热降低约17%,切向残余压应力有所减小,垂直珩磨速度方向拉应力减小并向压应力转变。结论超声振动使珩磨力和珩磨热有一定程度降低从而改变了残余应力的分布及数值;振动频率在20 k Hz波动时对残余应力的影响不大;磨削速度减小,切向残余压应力增大,垂直磨削方向残余拉应力减小;振幅增大时,切向残余压应力减小,垂直方向残余应力增大。     

Chip geometry and cutting force prediction in gear hobbing

This paper presents a tri-dexel geometric engine integrated simulation model for the gear hobbing operation. The process kinematics are modeled and validated using CNC signals from a Liebherr LC500 hobbing machine. Workpiece geometry updating and cutter-workpiece engagement (CWE) calculations are efficiently realized in the tri-dexel engine. 3D force contributions at discretized nodes along the hob's cutting edges are computed considering the localized principal cutting directions, and rake and inclination angles. To measure cutting forces, a rotary dynamometer is successfully adapted and used alongside a Kalman filter to compensate for structural dynamics. The predicted forces agree well with their experimental counterparts.     

基于灰色系统理论的柱塞套内圆珩磨过程模型研究

探讨利用灰色系统模型描述柱塞套内孔珩磨过程，利用灰色系统理论建立了柱塞套内圆珩磨过程尺寸精度的数学模型，结果表明，模型的精度高，计算值与实际测量值吻合程度较好，灰色系统模型适于描述内圆珩磨过程。     

圆柱齿轮滚齿加工三向Dexel模型仿真与验证

针对基于实体建模技术的滚齿加工仿真问题,开发一种圆柱齿轮滚齿加工三向Dexel模型仿真方法。研究圆柱齿轮滚齿加工的运动学模型。根据滚刀和齿轮毛坯的几何参数创建三角形网格模型,并转换为引擎内的Dexel模型。同时,借助Delaunay三角剖分和Alpha形状重构进行高效的CWE计算和未变形切屑几何仿真。采用斜角切削模型来计算每个时间步上所有啮合节点的力分布。使用利勃海尔LC500滚齿机对所提仿真方法进行了验证,并结合旋转测力计和卡尔曼滤波器来补偿结构动力学,从而进行准确的切削力测量。结果表明：所提方法能够准确预测出沿滚刀刃口离散节点的三维力分布,预测误差(均方根和标准差)在4%～12%之间,且当切削条件变化时,仍然可以准确预测轴向和横向的切削力,有助于进一步提高滚齿加工仿真的效率与精度。     

Prognosis of the local tool wear in gear finish hobbing

Gear finish hobbing is a method for soft finishing of external cylindrical power transmission gears. The application of this process is required when the process chain of gear production is to be set up completely free of coolant. Since this finishing technology is relatively new, there is some practical experience, but no fundamental knowledge regarding economical process design. One challenge in process design is that unbalanced tool wear typically leads to geometrical deviations of the machined gear profile. The aim of the investigations described in this paper is to develop a wear model which is capable to predict the local tool wear of gear finish hobbing tools. This model is based on analogy cutting trials and geometrical analyses of the chip geometries in gear finish hobbing. The results of the model are validated by fly-cutting trials with different local loads on the tool. The validation shows that an optimization of the local tool wear development can be achieved by means of the prediction model. Therefore, an optimization of the technological process parameters can be carried out based on this model to reach an efficient process design.     

内孔光整可调珩磨头的理论分析与试验研究

目的：目前对内孔的珩磨加工,一种珩磨头只能加工一种口径的内孔,加工尺寸单一,适应性差。为了提高珩磨头的通用性,适应小批量、多规格珩磨加工,介绍一种尺寸可调的珩磨头。方法对珩磨头尺寸调节原理进行了介绍,并分析了珩磨时工件所受的珩磨力以及珩磨头的运动情况。用SolidWorks建立了装置的三维模型,并加工出了适应孔径为95~125 mm的珩磨头实物样机。通过对内径为φ98 mm和φ106 mm的不锈钢钢管进行加工实验,加工6 min后,获取了表面粗糙度Ra变化曲线和加工后的表面形貌。结果加工后φ98 mm管的表面粗糙度Ra值由2.174μm降低到0.869μm,φ106 mm管的表面粗糙度由1.582μm降低到0.758μm。加工后的工件表面变得光滑、明亮,表面形貌得到明显改善。结论珩磨头结构简单易于实现,在普通机床上即可使用,通过实验验证了装置的可行性。     

Modeling of material removal rate and surface roughness in finishing of bevel gears by electrochemical honing process

This paper describes mathematical modeling of material removal rate (MRR) and surface roughness of the bevel gears finished by the electro-chemical honing (ECH) process. Since, ECH hybridizes electrochemical dissolution (ECD) and mechanical honing therefore, contribution of ECD in MRR and surface roughness has been modeled using Faraday's law of electrolysis while contribution of mechanical honing has been modeled considering material removal as a phenomenon of uniform wear and using Archard's wear model. Formulations are also proposed for computing the surface area, required by these two models, along the inter-electrode gap (IEG) based on the geometry of the straight bevel gear tooth surfaces. The developed models were experimentally validated using an indigenously developed experimental setup for finishing of bevel gears by ECH based on an envisaged novel concept of twin complementary cathode gears. An aqueous solution containing 25% NaCl + 75% NaNO₃ was used as the electrolyte. The predicted values of MRR and surface roughness have shown close agreement with the experimental values. The experimental results, SEM images and bearing area curve have shown appreciable improvement in the surface roughness and surface integrity ensuring better operating performance of the gears finished by ECH within an optimized finishing time of 2 min.     

Modeling and predicting of surface roughness for generating grinding gear

Gear surface has a significant effect on the load-carrying capacity and plays a crucial role for wear, friction and lubrication properties of the contact. However, most mathematical model of a generating gear grinding process trends to focus on grinding forces and temperature distribution in gear tooth. A new method for predicting gear surface roughness with the generating grinding process is developed in this paper. An algorithm for geometrical analysis of the grooves on the gear surface left by idea conic grains is given. To determine the final gear surface roughness produced by thousands of grinding wheel grains with randomly distributed protrusion heights, a search technique is proposed to systematically solve the gear surface roughness, which starts from the addendum circle along the involutes direction and ends at the dedendum circle. The numerical calculated results show that the surface of gear root part is smoother than that of gear top part.     

Simulation based model for tool life prediction in bevel gear cutting

Due to unpredictable tool life behavior in bevel gear cutting, unexpected production stops for tool changes occur. These lead to additional manufacturing costs. Because of its complexity, it is currently not possible to analyze the bevel gear cutting process sufficiently regarding tool life. This restriction leads to an iterative process design and determination of the ideal process parameters by using a trial-and-error approach. As a matter of fact, there is no concept to predict tool life in bevel gear cutting. Thus, a project has been initiated in order to develop a tool life model based on cutting simulation. This report presents the tool life model which combines a manufacturing simulation for bevel gear cutting with a regression model. The data of the regression model are determined by analogy trials. The combination of manufacturing simulation and regression model allows a local tool life prediction along the cutting edge.     

Identification of the specific cutting force for geometrically defined cutting edges and varying cutting conditions

Cutting force modeling is a major discipline in the research of cutting processes. The exact prediction of cutting forces is crucial for process characterization and optimization. Semi-empirical and mechanistic force models have been established, but the identification of the specific cutting force for a pair of tool and workpiece material is still challenging. Existing approaches are depending on geometrical idealizations and on an extensive calibration process, which make practical and industrial application difficult. For nonstandard tools and five axis kinematics there does not exist a reasonable solution for the identification problem.In this paper a co-operative force model for the identification of the specific cutting forces and prediction of integral forces is presented. The model is coupled bidirectionally with a multi-dexel based material removal model that provides geometrical contact zone information. The nonlinear specific forces are modeled as polynomials of uncut chip thickness. The presented force model is not subjected to principal restrictions on tool shape or kinematics, the specific force and phase shift are identified with help of least square minimization. The benefit of this technique is that no special calibration experiments are needed anymore, which qualifies the method to determine the specific forces simultaneously during the machining process. In this paper, experiments with different cutting conditions are analyzed and systematically rated. Finally, the method is validated by experiments using different cutting conditions.     

变双曲圆弧齿线齿轮切削仿真及参数优化

变双曲圆弧齿线圆柱齿轮（VH-CATT）是一种将圆弧齿线运用于齿轮齿线上的新型齿轮。由于缺少专用的加工机床,导致加工时其切削参数的调整较为复杂。为解决这个问题,根据其啮合原理及加工过程,利用ABAQUS对其切削加工过程进行模拟仿真;利用得到的数据,根据正交试验方法建立切削力的预测模型。利用鲸鱼算法,建立以加工效率与较小切削力为目标的函数优化模型,并通过加权求和法与归一化处理将它转化为单目标函数优化模型,通过鲸鱼算法得到优化后的切削参数。结果表明：所提出的单目标函数优化模型能够很好地对切削参数进行选定优化,以得到更好的加工效果;优化后的切削参数为主轴转速n=189.3 r/min,每齿进给量fz=0.046 mm,切削深度ap=1.89 mm。