Gear Shaving Research Articles

Влияние износа инструмента в процессе физического моделирования шевингования-прикатывания цилиндрических зубчатых колес на параметр шероховатости

The main issues related to the results of an experimental study aimed at modeling of the combined (cutting-deforming) finishing process of a gear processing, i.e. cylindrical gear shaving and rolling, under turning with a special combined cutting-deforming tool, which is a single-tip tool of a cylindrical work, divided into equal working areas. Due to the proprietary exploratory procedure used for prototype process, in one operation of a compact cylindrical work, a gear processing of a sufficiently large batch of horisontal wheels-representatives with average parameters, consisting of several thousand pieces, is simulated on a CNC lathe. The analysis of the results of the experiment was treated, allowing us to obtain information about gear processing of a large batch of gears in laboratory conditions. The roughness parameter of the work on workpiece areas is determined, the boundaries of tool degradation for this parameter are revealed. The revealed pattern of tool degradation appears to be the following: the prevailing wear of the tool occurs along the back surface due to its design feature, i.e. zero angle of its back, aggravated by the technological characteristics of the process (shaving - rolling), in which the back is involved in the surface plastic deformation, in particular, crushing a metal layer under the influence of a significant normal load. This results in frictional load taking place between its back surface and the surface of the proccesed workpiece. Tool degradation along the front surface, accompanied by its tool cutter blunting of its cutting edge, contributes to further deterioration of cutting process conditions (when stock removal of about 0.02 mm), and at the same time increases the proportion of surface plastic deformation (when shaving– rolling). This, as a result, increases the workpiece material share, which should be removed not by cutting, but by surface plastic deformation, thereby further redoubling a wear bit in its back surface.

Computerized design of plunge shaving tool for beveloid gears and plunge shaving characteristic analysis

A design model for beveloid gears with modification is first developed. Then based on the ordinary gear shaving machine tools’ structure, a plunge shaving model for beveloid gears is proposed. Based on the model, the installation relationship of a shaving cutter relative to a beveloid gear is derived and a surface generation model of a shaving cutter for beveloid gear is established. In the next, considering the shaving cutter's installation errors, a shaved beveloid gear model in installation errors is proposed. The effect of the shaving cutter parameters on the geometrical characteristics and the beveloid gear shaving precision is analyzed. The results show that increasing the tooth number of the shaver and the shaft angle can decrease the undercut risk of the shaver surface. Increasing the number of the shaving cutter's teeth and decreasing the shaft angle can weaken the effect of installation errors on the shaving precision. In the end, a simulation platform is established in the Vericut software, the feasibility of the proposed models for beveloid gear plunge shaving is verified. The proposed models achieve plunge shaving of beveloid gears in common gear shaving machine tools and precision manufacturing without distortion of beveloid gears with modification.

A finishing method for the continuous generation of spur face gears with shaving cutters

Face gear drives have been widely applied in power transmission, but the finishing of continuous generation is a difficult problem. This is mainly because the teeth of face gears are on a plane, which leads to interference by worm grinding. Hence, a shaving method for face gears is proposed in this paper. This work studies the theory of face gear shaving, the causes of mid-concave phenomena based on load tooth contact analysis (LTCA), a solution for the modification coefficient of the shaving cutter and a control method for the cutter location point. The experimental results show that the maximum machining error is −12.7μm, that many generating lines appear and that the residual stress increases by 49.2% in comparison with that of the grinding tooth surface. The present study suggests that the shaving method for spur face gears can not only achieve the finishing of continuous generation but also improve the surface integrity of the gear.

Elaboration of principles for developing technological systems for the finishing of gears

The service properties of gears are mainly formed at the stages of their finishing processing, such as gear grinding, gear shaving, final dimensional calibration, gear honing, smoothing, lapping, burn-in, etc. The main task of the technological systems synthesis for the gears finishing is to determine the optimal parameters and structure of the technological system that ensure the specified properties of the gears. This task is multivariate and is constrained by the absence of general principles for its solution, which determines the individual nature of the development. The proposed principles of design of technological systems for finishing processing on the basis of a system approach provides a solution to the problem of their synthesis in general, that is, by representing the technological system as a generalized design object. The synthesis method is implemented in the form of a logical design scheme, which is interpreted by the morphological model. This model is developed by decomposing the original design problem and regulates the synthesis of informational, optimization and algorithmic systems.

Study of Gear Honing of Cogwheels after Gear Shaving and Heat Processing

Study of Gear Honing of Cogwheels after Gear Shaving and Heat Processing

Study on Crowning of helical gear shaved by CNC shaving machine with three synchronous axes

Gear Shaving is the most efficient and economical ways to finish gears before heat treatment. The workpiece after shaving operation can reduce the running noise, which often used in the automobile industry. In this paper, we propose a mathematical model of a CNC shaving machine with multi-synchronous axes. The proposed mathematical model can be used to calculate the crowning tooth surface of the gear in parallel-shaving process.

Crowning Analysis of Involute Helical Pairs Shaved by CNC Gear Shaving Machine with Two Synchronous Axes

Gear Shaving is one of the most efficient and economical ways to finish gears after gear hobbing or gear shaping. In tradition, the shaved gear can be crowning by shaving machine with the rocking mechanism. In this paper, we propose a mathematical model of a CNC shaving machine with two synchronous axes. The proposed mathematical model can be used to calculate the crowning tooth surface of the gear in parallel-shaving process.

Advanced Design of a Gear Shaving Cutter with the Screw Cutting Edges for Finish Machining of Teeth of Gearwheels

Известны конструкции инструментов для чистовой обработки зубьев эвольвентных зубчатых колес со спирально-винтовыми режущими кромками, выполненными на одной боковой стороне витков. Обработка зубчатых колес производится при согласованном вращении инструмента и детали вокруг своих осей и перемещении их относительно друг друга в осевом направлении детали, причем обработка правой и левой стороны профиля зубьев возможна только после переустановки колеса. Недостатком этих инструментов является сложность конструкции и технологии изготовления. Известна конструкция инструмента червячного типа для чистовой обработки зубьев эвольвентных зубчатых колес (авторы Н. А. Чемборисов, Р. М. Хисамутдинов, В. А. Авдеев), выполненного с непрерывными винтовыми режущими кромками, при этом его винтовая поверхность имеет прямоугольный профиль. Недостатком этого инструмента является то, что режущий клин при его работе имеет не вполне удовлетворительную геометрию: передние и задние углы на режущих кромках практически равны нулю. Известен также инструмент (шевер) для чистовой обработки зубьев эвольвентных зубчатых колес, выполненный с непрерывными винтовыми режущими кромками, отличающийся от конструкции Чемборисова Н. А. и соавторов тем, что режущий клин имеет конструктивно выполненный задний угол (авторы Н. В. Сморкалов, В. П. Скрипин, В. П. Птицын, Ю. Ф. Белугин). Последовательная обработка правой и левой стороны профиля зубьев колеса разными винтовыми режущими кромками данным инструментом обеспечивает повышение его стойкости, а также существенно уменьшает вспомогательное время, исключая необходимость переустановки колеса и тем самым повышает производительность процесса. Разработана усовершенствованная конструкция шевера с винтовыми режущими кромками для чистовой обработки зубьев зубчатых колес, которая позволяет улучшить врезание инструмента в металл, уменьшить деформацию стружки и улучшить ее сход, уменьшить силу и мощность резания.

Research on shaving processing of spiroid face gear

To reduce tooth surface errors and improve the quality of tooth surface morphology for the spiroid face gear manufactured roughly by die-casting, a method of shaving processing for this type of gears was developed. According to the differential geometry and the meshing theory of spatial crossed axes gears, the kinematics of the shaving processing for the spiroid face gear was analyzed, while the cutting velocity of both contact tooth surfaces was derived to illustrate the feasibility of gear shaving. With the designed tooth geometry of the shaving cutter, the simulation of generation of tooth surfaces for the spiroid face gear was developed. Machining experiments for such type gears were performed on a five-axis computer numerical control machine tool (CNC machine) with the axially grooved shaving cutters. The geometric error measurement of the shaved spiroid face gears was determined by D40 CNC gear measuring center. The research results are of sound great significance to improve the engagement and lubrication for the spiroid face gears.

Determination of the profile of the worm-type tool

The cutting wedge of disk shaver at gear shaving has not fully satisfactory geometry: clearance The cutting wedge of the disk shaver when gear shaving is not fully geometrically satisfactory. The clearance on cutting edges are practically equal to zero. We would suggest this is the reason that the disk shavers machining of gear-wheels with large allowance is not possible. The construction of a worm-type tool is known also for clean machining of points of involute of gear-wheels made with continuous spiral cutting edges. The difference of this construction from the construction of N. Chemborisov is that a cutting wedge has the structurally made clearance α (Authors: N. Smorkalov, V. Skripin, V. Ptitcin, IU. Belugin). Polishing of side of coil is the most responsible and labor intensive operation when making a worm-type tool with the continuous spiral cutting edges of construction of N.Smorkalov and other.Dependences allowing to define the coordinates of key points of axial section of side of coil of the worm-type tool were obtained. These coordinates will allow to define the parameters of setting of abrasive disc in relation to the worm-type tool.

Heuristic Feature Selection for Shaving Tool Wear Classification

In this paper, we develop and apply feature extraction and selection techniques to classify tool wear in the gear shaving process. Because shaving tool condition monitoring is not well-studied, we extract both traditional and novel features from accelerometer signals collected from the shaving machine. We then apply a heuristic feature selection technique to identify key features and classify the tool condition. Run-to-life data from a shop-floor application is used to validate the proposed technique.

Effect of gear teeth finishing method on properties of teeth surface layer and its resistance to pitting wear creation

This work presented the characteristics of two gear teeth finishing methods, due to the properties of gear teeth surface layer obtained at the tooth working depth. These methods are: 1) the teeth carburization, hardening to a hardness of HRC 60-62 and then grinding, 2) the soft gear shaving as the final mechanical treatment and then carburizing and hardening to the hardness of HRC60-62. This work included the test results of the contact fatigue strength carried out on the circulating power system. The Wohler curves were plotted due to the obtained results, as the basis for the practical evaluation of the considered gear finishing methods. The parameters like volume distribution of the voids, content of the retained austenite, compressive residual stress value, but also the results of contact fatigue strength tests, are more favorable for the teeth shaving method than for the teeth grinding method.

S112041 高速同期ギヤホーニングによるギヤシェービング工程の廃止([S112-04]伝動装置の基礎と応用(4))

This report outlines that investigation conducted on the OBD stock removal, influence on honing stone breaking by burr of tooth edge, mass productivity and gear noise, in order to eliminate gear shaving process by high-speed synchronous gear honing. As a result of the investigation, it was verified that high-speed honing condition can be decided if the normal base stock removal per work revolution was used. In addition, it has been confirmed that burr of tooth edge have no influence on honing stone breaking and gear accuracy, besides the noise level of this honing gear is same as honing gear which has gear shaving process.

Numerical Control Reformation for Gear Shaving Machine

A numerical control (NC) reformation scheme is presented to reduce the failure rate and improve the performance and efficiency of the old gear shaving machine. On the basis of study the mechanical structure and shaving methods, the numerical control system 828D and the servo driver S120 developed by Siemens Company are used to replace the old control system. The diagonal shaving method is selected to design shaving program after analysis of the process route. The reformation completed parametric programming, realized numerical control of the shaving machine and improved the reliability and flexibility of the system.

Kinematic calculation of the error in gear shaving

Kinematic calculation of the error in gear shaving

Analysis of auxiliary crowning in parallel gear shaving

Gear shaving is one of the most efficient and economical ways to finish gears roughed by gear hobbing or shaping. In parallel gear shaving process, the tooth profile of workgear can be longitudinally crowned by an auxiliary crowning mechanism that rocks the workgear with respect to a moving pivot. There are two independent motion parameters in parallel shaving, the tight rotational meshing between workgear and shaving cutter and the traverse motion of the workgear by moving pivot. A mathematical model for the tooth profile of workgear finished by the parallel shaving process is proposed to simulate the kinematical motion of parallel shaving process with the auxiliary crowning mechanism by two parameter meshing equations. The proposed mathematical model is verified by experiment and can be applied to calculate the crowning of the workgear from the machine setup of crowning mechanism.

Even contact design for the plunge shaving cutter

Gear shaving is a highly efficient and economical cutting method in gear finishing. The tooth profile of the plunge shaving cutter is usually sharpened by a cone grinding wheel on the cutter resharpening machine. The resulting radial prestressing force between the work gear and shaving cutter is constant in the final stage of the shaving process. Assuming that the cutting force on the work gear is evenly distributed on the instantaneous contact lines, and the cutting depth of each cutting mark is inversely proportional to the total length of the instantaneous contact lines. This paper thus proposes a mathematical model that summarizes these instantaneous cutting marks and estimates the final shaved tooth surface of the work gear. It also provides guidance for designing the geometric data for a plunge shaving cutter to satisfy the even contact condition.

A New Method for Profiling Gear Plunge Shaving Cutter on Gear Shaving Machine

The gear plunge shaving process is a widely used process for soft finishing of gears in the gear manufacturing industry. But it is difficult and expensive to profile plunge shaving cutter, because the cutter must be ground by a cone grinding wheel on a special grinder. A new method, profiling gear shaving cutter on the shaving machine, i.e. a CBN dressing gear which has the same parameters with the machined gear is clamped in place of the workpiece on the shaving machine and profiling the cutter in shaving process, is put forward. Meshing and Tooth contact analysis of shaving cutter profiling has been considered. Meshing equation of profiling process and equation of shaving cutter gear blank after profiling are obtained. Experiment testified that it is an applied method and has many advantages.

A New Method for Profiling Gear Plunge Shaving Cutter on Gear Shaving Machine

A New Method for Profiling Gear Plunge Shaving Cutter on Gear Shaving Machine

Improvements in gear shaving

Efficient finishing of cylindrical gears is considered. In particular, attention is paid to the dependence of the resulting surface roughness on the cutting conditions and the direction and position of the chip channels in the shavers.