Gear Shaping Research Articles

多軸加圧動作による厚板容器壁への歯形成形工程の改善

There are many demands for cup-shaped parts with a gear shape in the automotive industry and a large load is often required for the complete filling of the gear portion in conventional progressive forming. In this study, a new method was proposed for solving the problem using a multi-action press. This method features the operation of depressing the cup wall to provide an appropriate shape for gear filling with the cup corner prior to gear forming. Experiments and FE analysis were carried out, varying the amount of cup wall depression. The filling ratio of the gear increased with increasing amount of cup wall depression and complete filling was achieved with a low load compared with progressive forming. An increase in load and burr formation were observed after the cup corner reached the bottom of the die. Accordingly, the optimum conditions for cup wall depression should be determined so that the unfilled portion is minimized at the stroke that the cup corner reaches the bottom of the die.

머신비전을 이용한 타원형 기어 검사 시스템에 관한 연구

타원형 기어는 오발 유량계에 사용되는 특수기어로써 타원형 모양에 의해 생긴 공간으로 물을 흘려보내 계측한다. 본 연구의 목적은 타원형 기어의 가공정도를 판단하고 불량을 가려내는 시스템을 머신비전을 이용하여 개발하는 것이다. 각종 산업분야에서 자동화가 확산되면서 머신미전의 수요는 늘고 있으며 업계전반의 생산공정 중 검사 공정에서 빼놓을 수 없는 인자가 되었다. 하지만 머신비전을 이용한 기어측정은 기어의 형상이 복잡하다는 이유로 잘 사용되지 않고 있다. 본 연구에서는 머신비전을 이용한 검사 프로그램으로 타원형 기어의 측정이 가능함을 보였으며 본 연구에서 설계한 타원형 기어의 가공정도를 판단할 수 있었다.

Preparation of Aluminum Feedstock for Green Part Specimen Using Metal Injection Molding

In metal injection molding, to identify the homogenous aluminum based feedstock is a challenging issues. In this study, a metal injection molding of aluminum feedstock which contains of high density polyethylene, stearic acid and paraffin wax as binder system was performed. The feedstock are used to produce tensile and gear shape green specimens using injection molding machine. The process ability of the metal injection molding feedstock depends on different parameters such as their binder composition and amount of metal powder used. From this study, the percentage of volume shrinkage experienced a sudden increase at the metal composition more than 50%. It also shown that, the paraffin wax content, affects the feedstock performances.

Research on the Space Meshing Tooth Profile of Giant Magnetostrictive Harmonic Motor

A methodology to calculate the meshing tooth of giant magnetostrictive harmonic motor is proposed in this paper. The deformation curve of the flex spline of the giant magnetostrictive harmonic motor was investigated with Fourier function. A kinematic model of harmonic drive was established when the involute profile is selected as the flexible gear tooth shape and the circular spline is obtained following the envelope theory, thereby generating the kinematic simulation as well as the trajectory of the circular spline teeth with respect to the flex spline. Finally, the relationship between the cone angle of flex spline and the engagement profile is discussed; together with an improvement strategy-equal width shrinkage of circular spline.

Numerical Simulation of Gear Shaping for Planetary Gear Based on the MASTA Software

In this paper, the gear shaping of some planetary gear was simulated. The simulation results show that via the gear shaping process, the gear tooth surface on the left has a single tooth pitch deviation of about 1.2 um, and the gear tooth surface on the right has a pitch deviation of 1.1 um, accordingly. By combining the simulation of two-dimensional and three-dimensional gear shaping models, this paper can not only realize accurately the gear shaping process of the planetary gear, but also provide some certain reference for the gear shaping processing.

The Dynamic Analysis of Reduction Gearbox of NC Gear Shaper Based on ADAMS

The key factors of NC gear shaper working steadily are directly influenced by the mechanical properties of reduction gearbox of NC gear shaper .The reasons of the reduction gearbox of NC gear shaper producing vibration have been studied in condition of unstable load when it works based on ADAMS . The speed of shafts and the meshing force of gears are obtained from the dynamic simulation analysis by the virtual prototyping technology . It shows that the reduction gearbox of strength of the vibration increases from input shaft to output shaft and the vibration strength which reduction gearbox works in the unstable input speed is greater than that in unstable load torque.

Research on Mathematical Modeling and Kinematic Simulation of Elliptic Family Gears

Elliptic family gears are commonly used in non-circular gears, which include elliptic gear, high-order gear, elliptic deformed gear and high-order deformed gear, thereinto high-order deformed gear can include the elliptic family gears through adjust its order and deformed coefficient. Because non-circular gear has different tooth profile in different position of pitch curve and there is difference in the left and right tooth profile of the same gear tooth, thus the CAD modeling of non-circular gear is difficult for these characteristics; but the precise model of non-circular gear has important significance to the realization of numerical control machining, kinematic simulation and relevant mechanical analysis. This paper deduce the corresponding pure rolling mathematical model based on the pure rolling contact theory that cylindrical gear and non-circular gear mesh in the end face, and realize the CAD modeling of non-circular straight and helical gears by letting the cylindrical gear and non-circular gear make solid geometry operation, which is suitable for pitch curve with convex and concave. The non-circular gear shaping methods with equal polar and equal arc length are simulated by setting different discrete polar angles, and the transmission ratio curve and the angular acceleration curve of driven gear are get through the kinematic simulation of gear pair, which realize the transmission performance analysis of elliptic family gear pair. The above research results can be applied to the modeling and kinematic performance analysis of other non-circular gears.

Optimization Study on the Tooth Profile of Gear Shaping Roller of Honeycomb Semi-Cell Structures

In order to solve the problem of low accuracy of honeycomb semi-cell structures which are rolled by traditional trapezoidal tooth profile gear shaping rollers, conjugate trapezoidal tooth profile gear shaping rollers have been put forward to improve the quality of honeycomb semi-cell structures, basing on the theoretical analysis. Using ANSYS/LS-DYNA, a finite element model of rolling aluminum foils by two kinds of tooth profile shaping rollers was set up. Then results of numerical simulation indicate that the honeycomb semi-cell structures rolled by the conjugate trapezoidal gear shaping rollers are closer to the ideal size than those rolled by the traditional trapezoidal gear shaping rollers.

The Herringbone Gear Box Modal Analysis and Experimental Study

In order to more accurately estimate the intrinsic mode of herringbone gear transmission box, fluid-structure interaction model of gear box and lubricants is established. Gear system natural frequencies and mode shapes is calculate out on the establishment of the fluid-solid coupling dynamics equations. The finite element models of gearbox and lubricating oil are build by ANSYS software, and the results of inherent characteristics are given. The top ten order natural frequency is distributed between 611.8HZand 2487HZ, and the first two order mode shape is respectively shown as the axial swing and horizontal swing. In order to verify the analysis results, the hammering method of single-input multiple-output (SIMO) is used to test gearbox structure modal. The results show that the mode shapes get from ANSYS analysis are consistent with the datas of experimental measurements, and the maximum deviation of natural frequency between experiment and theory is blew 15%. So it can be shown the fluid-structure interaction model in this paper is effective and reasonable.

The Analysis of Bearing Life of Drive Gear Box of NC Gear Shaping Machine Based on Romax

As the key system of NC gear shaping machine, the principle property of the drive transmission system have a decisive influence upon a complete machine. The virtual prototype of drive gear transmission system was created by Romax analysis software in this paper, and made simulation after establishing some constraint conditions according to the working conditions. Both ISO 281 and Romax Adjusted are applied to analyze and predict fatigue life of each bearing, then through using the principle of Miner, all the damage percentage were added together under different conditions. The results showed that all bearings used in the virtual prototype of drive gear transmission system meet the requirements of mechanical performances. This study provides theory basis for follow-up design and optimization on NC gear shaping machines drive transmission system.

The Modal Analysis for the Third Type of Internal Gear Motor

It is significant to study the dynamic characteristics of the mechanical system. In order to prevent accidents such as resonance and self-excited shock, modal analysis of the mechanical systems should be analyzed. The mode shape of gears was analyzed to improving the design security. The sleeve, the planet gears and the internal gear of the motor were simulated. All order natural frequency, the mode shape of the motor was obtained. Research shows that motor running is smooth when the frequency is less than 4230Hz.

Research on Three-Dimensional Topology Optimization for the Bed of NC Gear Shaper

Taking minimum compliance of the bed of YKS5120B-3 NC gear shaper as the optimization objective, and the three-dimensional finite element relative density as design variables, the three-dimensional topology optimization mathematical model is established based on the interpolation method of solid isotropic material. The optimality criteria algorithm is used to update design variables. Topology optimization design of loaded bed is conducted and the optimal bed material distribution in the design domain is obtained. The new geometric model of the bed is reconstructed according to the optimal bed material distribution. Comparing the static analyses results of original model of the bed with reconstructed model of the bed, the correctness and the validity of the proposed method is verified.

Computer Aided Design and New Manufacturing Process of Spherical Hob

According to the working principle of spherical hob, computing formulae of normal and axial profile of the spherical hob are deduced, and calculation methods of other main parameters are introduced in the paper. Then the computer aided design and calculation of spherical hob is realized by Visual Basic programming language, which increases the calculation speed and accuracy. And the new manufacturing process of making spherical hob blade by using gear shaper cutter is put forward which can be finished on universal machine tool, so the application and popularization of spherical of hob can be promoted. At last the experiment proves that the internal gear machined by spherical hob meets the demand of precision.

5PM3-PMN-013 液中マイクロロボット実現のための液中小型ヒートエンジンの基礎研究(OS4 電池レス・デバイスのためのエネルギーハーベストの展開,ポスターセッション)

In this paper, we describe design and development of proof-of-concept prototype of a micro heat engine for an in-liquid micro robot. There are two main problems to develop a micro robot within 1mm^3. Those are a sticky problem and an energy source problem. To solve those problems, we look at the natural world and found out almost all micro animate beings are living in liquid such as microbes and water fleas. They harvest energy by eating foods and absorbing solar energy, and they move freely in liquid; they have already solved sticky problem and energy source problem. That is our motivation to research and develop micro robot which moves in liquid. In this report, we have proposed new concept of the robot using heat engine composed of gear and pulley and shape memory alloy actuator as its source of motion. We make 1cm3 sized proof-of-concept prototype of the heat engine to check its basic performance. We also discuss about possibility and applications of the in-liquid micro robot.

A Gear Cutting Predictive Model Using the Finite Element Method

Current processes for producing transmission gears involve hobbing, milling or shaping of a forged stock to obtain the gear shape. Gears are typically formed by hobbing tools made from solid tooling material, such as tungsten carbide, and have dozens of teeth. The gear hobbing process entails several teeth in cut simultaneously. Generation of in-volute tooth profiles results in varying chip loads from pass to pass. In this paper, details are provided for a finite element-based model of gear hobbing and milling processes. The model explicitly meshes gear cutter geometries with dozens of teeth. These cutters are used to simulate the complicated kinematic motion between tool and workpiece. Thermo-mechanical coupled calculations within an explicit dynamic formulation are per-formed on the tool and workpiece during chip removal. The complex geometry of involute tooth profiles results in complicated contact scenarios on the evolving workpiece geometry during tooth profile generation. Tooth-workpiece-chip contact is enforced rigorously and is particularly complicated with the confined space of gear hobbing. Advanced adaptive meshing strategies are developed and employed to maintain the resolution of the tool-workpiece interaction while multiple teeth are in contact. Cutting forces, temperatures and stresses in the tool and workpiece are predicted for steel workpiece materials. Models are validated through a set of initially simplified experiments where incremental complexity is added, allowing for direct comparison between predicted and measured forces and chip shapes.

A Study on the Development of Micro Metal Gear with Outer Diameter of 500um Using MIM Process

At present there are many studies that are carried out to develop micro parts. A micro drive unit assembled with several micro movable parts is needed to industrialize the functional micro parts such as micro pump, micro-chip, micro motor, and micro gear. In this study, a powder injection molding process was used in making micro metal gear with outer diameter of 500um. To make micro metal parts, it necessary to create micro shape cavities and cores for the filling of feedstocks. To make micro shapes or patterns, there are several methods to choose such as LIGA, laser machining, micro etching, and micro milling. But these micro methods are expensive and need some special facilities to fabricate. So in this study, conventional machining methods were tested to make micro gear cavity shapes. The preliminary studies were conducted to evaluate the filling of cavity and the EDM machining. Finally micro gear with outer diameter of 500um was injection molded, de-binded, and sintered. Some incomplete fillings occurred at the end of filling gear teeth using 17-4PH 3F feedstock. The final sintered micro metal gear showed about 434um of outer diameter.

Research on the Parametric Design of Involute Helical Gear Based on Pro/Program

Involute helical gear has advantages of larger overlap coefficient, steady transmission, lower impact and noise, higher load bearing capacity, longer life, so it is widely used in machinery, mining, metallurgy, aerospace and other fields. However, due to the involute helical gear tooth profile shape is more complex, and some low-level CAD software is difficult to directly generate a three-dimensional helical gear tooth profile. According to involute helical gear formation principle, this paper presents an effective method to establish the three-dimensional model for involute helical gear .In this paper, a parametric design method of realizing involute helical gear 3D model by using Pro/E modeling functions and Pro/Program programming is discussed. This method can enable designers to obtain helical gear 3D solid model quickly and accurately by inputting a little geometry characteristic parameters. It can also enables designers quickly update design based on the existing 3D gear model, so as to improve the design efficiency.

The Finite Element Analysis of Machine Tool Column of NC Gear Shaper Based on HyperWorks

The 3D model of machine tool column of NC gear shaper is created in Pro/E. This model is imported into the HyperWorks by STEP file. The column structural static stress and deformation, the five-step modal natural frequencies and mode of vibration are obtained by Hyper Works static and dynamic analysis. Based on the analysis results, this study offers a kind of reference comments for the design and improvement of machine tool column of the gear shaper.

Calculation Equation of Tooth Face of Shaping Gear for Logarithmic Spiral Bevel Gear

According to the processing principle of the spiral bevel gear, analyzed the relative motion of cutter and workpiece in process. Combing the feature of logarithmic spiral bevel gear, this paper took the advantage of the gyration vector expansion to derivate the tooth surface equation of logarithmic spiral bevel gear shaping gear and deduced the meshing equation.

Analysis of mixed model in gear transmission based on ADAMS

The traditional method of mechanical gear driving simulation includes gear pair method and solid to solid contact method. The former has higher solving efficiency but lower results accuracy; the latter usually obtains higher precision of results while the calculation process is complex, also it is not easy to converge. Currently, most of the researches are focused on the description of geometric models and the definition of boundary conditions. However, none of them can solve the problems fundamentally. To improve the simulation efficiency while ensure the results with high accuracy, a mixed model method which uses gear tooth profiles to take the place of the solid gear to simulate gear movement is presented under these circumstances. In the process of modeling, build the solid models of the mechanism in the SolidWorks firstly; Then collect the point coordinates of outline curves of the gear using SolidWorks API and create fit curves in Adams based on the point coordinates; Next, adjust the position of those fitting curves according to the position of the contact area; Finally, define the loading conditions, boundary conditions and simulation parameters. The method provides gear shape information by tooth profile curves; simulates the mesh process through tooth profile curve to curve contact and offer mass as well as inertia data via solid gear models. This simulation process combines the two models to complete the gear driving analysis. In order to verify the validity of the method presented, both theoretical derivation and numerical simulation on a runaway escapement are conducted. The results show that the computational efficiency of the mixed model method is 1.4 times over the traditional method which contains solid to solid contact. Meanwhile, the simulation results are more closely to theoretical calculations. Consequently, mixed model method has a high application value regarding to the study of the dynamics of gear mechanism.