Parameter Design for Machining Quenched Internal Helical Gears by EDM

Aiming at the problem of machining quenched internal helical gears, a method and its equipment are discussed and designed, which is used for machining quenched internal helical gears by EDM. Its characteristic and principle are proposed. The modifying design of the electrode gear and the calculating method of its modification coefficients is presented. Analyzing for the error of the machining equipment is done. The results show that this problem can be solved by EDM, the electrode gear is the modification gear of machined gear and the machining accuracy can be improved by controlling errors.     

The Development in Finish Machining of Hardened Gear

This article summeried the methtods in finish machining of hardened gear and mainly introduced the development of the form grinding technique in grinding wheel dressing and grinding technology. The technique, which makes use of CBN tools, of hardened gear finish machining is also briefed.     

Worm wheel grinding method of convex pitch line non-circular gear

To overcome the precision machining difficulty of non-circular gear, a convex pitch curve of non-circular gear and worm grinding method is presented. Firstly, worm wheel is reduced to rack cutter and a rack machining convex pitch curves of non-circular gears sport model is set up. Then based on the structure of CNC worm wheel grinding machine tools and machining principle, electronic gear box of machine tools is designed and active and following axes are planned. At the mean time, the synchronous coefficient of machine tools between synchronization is deduced by machining principle of equal arc-length, and interaction models of grinding are established. At last, the worm wheel manual presetting cutter methods with non-circular gear are given and worm grinding wheel mounting angle, axial position and axial location parameter can be adjusted along the gear.     

EDM Generating Technology of Quenched Internal Gear

Based on the infroduction of the present process of quenched internal gear, a new technolgy of machining quenched internal gear-EDM generating technology is presented with its principle and machining processes. .     

Accurate mathematical models for relief grinding of gear hob cutters

A mathematical model for accurate relief grinding of gear hob cutters along radial directions is presented based on the analysis of grinding geometry. Both the design and manufacturing models of gear hob cutters are carefully derived and presented. By employing the plane envelope theory, the reference contour of the grinding wheel is determined in order to attain the design tool profile precisely. The tooth profile error model after regrinding is also given to confirm the grinding parameters. The model provides accurate solutions for both the tool profile and the sectional contour of the grinding wheel. It is simple and straightforward and can be used to produce high precision hob cutters systematically. Two numerical examples are presented to illustrate the effectiveness of the proposed method. The model computing results indicate that the proposed method is practical, precise and reliable. The method provides valuable reference for the design and machining of hob cutters.     

Intensity Comparative Analysis Based on Ideas Between Involute Gear and Double Involute Gear

Modeler and simulation modules in Ideas software are used to build the finite element models on involute gear and double involute gear with accurate tooth shape, and with the same design parameters and under the same loads, finite element contact analysis has been done. At last, the contact stress and bending stress on the two types gear transmission at the different meshing positions are solved out, and comparative analysis and study have been done. At the same time, that the ladder-shape tooth on the double involute gear how to influence contact stress and bending stress is emphatically analysed. All above offer the theoretical foundation that bring the double involute gear with ladder-shape tooth into the industry.     

Study of Tooth Contact and Kinematic Precision on Cone-Generated Double Enveloping Worm Gearing

The tooth contact and kinematic precision of cone-generated double-enveloping worm gearing with machining and assembling errors have been investigated. The influence of different errors on driving quality has been discussed. The assembling method to reduce or eliminate the influences of machining errors on tooth contact and kinematic precision has been proposed.     

Recent Development of Nanocrystalline and It's Mechanical Machining Technology

Nanocrystalline materials is a new area in materials science, because it possesses some special functions in sound, light, electric, magnet and heat and advance performances. This paper reviews the recent developments of nanocrystalline materials, describes in details its manufacturing methods and studies initially its forming and machining technologies.     

PREDICTION OF QUATITIES CONTROL OF STRAIGHT BEVEL GEAR SHAPING

Based on the forming and meshing theories of gears, the relationship between machining parameters and driving quatity of straight bevel gears has been discussed. The forming and meshing processes have been simulated with a microcomputer. The correctness of the theoretical analysis and calculation has been proved by shaping experiment.     

Contact analysis of a new style planetary reducer with a double crank and internal gear board

To address the problems of low carrying capacity and short life of bearings in current ring reducers, a new type of ring reducer is proposed which consists of a two stepped transmission. One is a planetary transmission, and the other is an N type planetary transmission with a low tooth number difference. Based on the analysis of structural features, the transmission principle, and a transmission load situation, a contact finite element model of the new type of ring reducer is set up, and the stress value and the actual pairs of meshing teeth are derived by calculation. Based on gear modification research theory, the second stage transmission gear pairs of the new reducer are modified on its teeth profiles. Results demonstrate that the load capacity of transmission gear pairs have been enhanced greatly.     

Site tools distribution method for machining job shop and its implementation

Aiming at site management problems of machining job shop, a site tools management method based on dynamic distribution for machining job shop is proposed. According to the method, the site dynamic distribution plan of machining tools is generated. A site tools distribution management information system is developed. The function and information models of the system are presented. With the system, dynamic distribution and recycling of machining tools and materials is realized. As a result, the inventory of machining tools is reduced, and the productivity is improved. The system has been applied in a machining job shop with satisfied result.     

Transmission model of higher-order elliptical bevel gearing and motion simulation for interference checking

Higher-order elliptical bevel gear is a typical form of the noncircular bevel gear transmission.Space spherical coordinate system of the bevel gear meshing is set up based on the meshing theory of space transmission.The varying relationship among the pitch curve,tooth profile and mesh lines are analyzed,and the equation of the gear tooth surface is developed with matrix method based on space coordinate transformation.The basic parameters of the noncircular bevel gear such as transmission ratio,modulus and the number of teeth are designed,and detailed analysis of the influence of the eccentricity on the relevant parameters is carried out as well.By using discrete numerical method and three-dimensional software,the mathematical model of the tooth profile and virtual physical model of the noncircular bevel gear are established,and then simulation on its motion and interference checking are performed.Finally,the approach for design,calculation and generation of the tooth profile is obtained and its correction has been verified by experiment.     

The Study Evolution of Gear Electric Erosion Phenomenon

This paper introduces phenomenon of electric erosion of gear and the research condition and evolution of it; puts forward a point of view that a system of electric erosion of gear is a especial tribology system which is in relation to many subjects and in which many phenomena exist and coupling each other , moreover , it is very difficult and complex to study electric erosion of gear by experiment ; have made statistical datas about typical example of electric erosion of gear inland ,at this base ,summarizes characters of electric erosion of gear and the study means of it.     

The Study on the Electric Erosion Mechanism of the Gear Surface

The bar and the cloud microcosmic appearance character of the electric erosion is described in this paper.The electric erosion mechanism of the gear surface has been set forth by setting up the model of electric erosion of the discharge not contacted and the model of electric erosion of discharge contacted. The electric erosion of the discharge not contacted would be taken place when the voltage is stronger and the lubricating oil film formed better between the space of the gear surface. The electric erosion of the discharge contacted would be taken place when the voltage is lower and the lubricating oil film formed not better between the space of the gear surface. The failure of the gear is accelerated by the action of the electric erosion and the friction wear together.     

Optimization of Structure Parameters in Ultra-precision Plane Honing

The structure parameters of honing wheel have effects on machining accuracy in ultra-precision plane honing. This paper put forward to the optimization of structure parameters. By calculating the machining accuracy coefficient and wear coefficient of triangle radial structure honing wheels, it is obvious that the suitable triangle radial structure honing wheel can improve machining accuracy of workpiece.     

传递功率对行星齿轮传动系分岔特性的影响规律

针对行星齿轮减速器工作过程中传递功率的频繁变化容易导致其运动状态发生突变的问题,探讨行星齿轮传动系统随传递功率的分岔特性。基于2K-H型行星齿轮传动系统纯扭转非线性动力学模型,采用CPNF(continuous Poincaré-Newton-Floquet)方法研究了传递功率对行星齿轮传动系统周期运动稳定性的局部精细分岔规律,运用直接数值积分的方法绘制了系统随功率的全局分岔图,并对两种仿真结果进行了对比。结果发现,在某些参数组合下,行星齿轮传动系统会共存几个稳定或不稳定的周期轨道;当功率在196~220 kW范围内,随着功率值的逐渐增大,行星齿轮传动系统的各种形态的周期轨道均是通过倍周期倒分岔的途径在相应功率分岔点处发生稳定性突变的;在轻载工况下(传递小功率),行星齿轮非线性系统容易呈现混沌运动状态。     

SOME NEW MACHINING METHODS WITH THE AID OF COMPOUND MOTIONS

The paper describes a new theory and methods for designing hyperbola, degenerate circles, involute and roulette curves which have been applied in grinding convex involute gears, cutting special profiles on a gear shaper, grinding the race-way of ball thrust bearings, form grinding and grinding cyclo-cycloidal gears with an abrasive belt. All these applications have been used in industruy with considerable benefits. The curves are produced by different combinations of straight line and circle motions, Given the curve parameters of the workpieces to be machined, the best approximate curve can be obtained from a computer program designed for this purpose.     

Separated Teeth Gear for Grinding Test

A kind of rational structure gear,separated teeth gear,in applied to grinding test.The contadiction between the heavy weight of the tested gear and the high precision of the measuring instrument is ideally solved.The gear is tested and verified by experiments.     

储粮新技术应用前景展望

通过分析粮食储藏领域在“十一五”期间研究、开发的新技术和国际上目前正在开展的粮食储藏技术研究情况,提出了“十二五”储藏科技研发应用的建议.     

Analysis on Oylindrical Worm in Traction Machine and Modifications

Cone enveloping cylindrical worm in traction machine as instance, theoretical analysis on cylindrical worm transmission has been theoretically analyzed, and efficiency test and load capability test of traction machine with YJ240 cylindrical worm have been done on open power gear experimental instrument. According to the experimental data, it indicates cylindrical worm have some weaknesses on load capability, efficiency, adjustment possibility of tooth backlash and so on. Therefore, on purpose of improving integral performance of traction machine, face worm with variable tooth thickness may be used as primary drive mechanism in traction machine instead of cylindrical worm.