最新刊期
      期 5 ， 2019
      本期电子书

        Theory·Reserach

      • Lei Xiao,Hai Zhang,Baoyu Xu,Chengzhe Wang,Xiaoru Hao
        Vol. 43, Issue 5, Pages: 1-5(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.001
        摘要：For permanent magnetic gears （PMGs）， each transmission ratio can be made by several combinations of the numbers of magnetic pole pairs （NMPP） on the driving and driven rotors. In order to investigate the influence of NMPP on transmission efficiency and output torque， transmission ratio i=5 is selected， PMGs with 6 combinations of NMPP and corresponding two groups （each group has 6 combinations） are analyzed， the 6 combinations of NMPP on driving/driven rotors are 2/10， 3/15， …， 7/35. Finite element analysis （FEA）simulations indicate that variations of output torque to NMPP on driving rotor （Ph） are quadratic curves with peak values occurring at Ph=4， variations of transmission efficiency to Ph also show quadratic curves basically but with slow change and a little higher values occurring at Ph=4~7. So it is concluded that considering output torque and transmission efficiency together， for PMGs with transmission ratio i being close to 5， the NMPP on driving/driven rotors （Ph /Pl） should be selected as 4/19 to get a better transmission characteristics.  
        关键词：Radial modulated;Permanent magnetic gear;Output torque;Transmission efficiency;Finite element analysis   
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        发布时间：2022-10-03
      • Jincheng Dong,Sanmin Wang
        Vol. 43, Issue 5, Pages: 6-12(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.002
        摘要：The mode transition will bring about the dramatical changes of the dynamics characteristics of the herringbone gear power-split transmission system， so the mode transition phenomenon must be analyzed in the process of the transmission system dynamic design. The torsional vibration model and the free torsional vibration differential equations of the herringbone gear power-split transmission system are established， and the torsional vibration models are classified to two kinds of the coupled vibration mode and the branch gear vibration model by calculating the torsional vibration natural frequency and vibration mode. On this basis， the mode transition phenomenon of the transmission system is studied， and the criterion of mode transition phenomenon is determined， the mode transition phenomenon is not going to happen between two different types of modal vibration mode， and will happen between the same types. Finally， the accuracy of the proposed mode transition criterion is verified by an example.  
        关键词：Herringbone gear;Power-split transmission;Mode transition;Natural frequency;Mode shape   
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        发布时间：2022-10-03
      • Hongbin Yang,Guanyun Li,Ruiyi Li,Aijun Xu
        Vol. 43, Issue 5, Pages: 13-17(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.003
        摘要：The method of surface reconstruction is studied to realize the rapid reconstruction of the three-dimensional model of single-piece worm gear. Point cloud data is obtained by non-contact 3D scanner， and point cloud data is preprocessed and surface reconstructed by using reverse engineering software Imageware. The two methods of curve fitting surface and point cloud directly fitting the surface are mainly discussed， and the fitting precision and smoothness of the surface obtained by the two methods are compared， and the alignment of the reference coordinate system and subsequent solid modeling operations of the worm wheel three-dimensional model is completed in UG. The results show that the method of curve reconstruction surface can better meet the accuracy and smoothness requirements of the worm gear tooth surface. This method can quickly realize the accurate reconstruction of the three-dimensional model of the worm wheel， and a CAD model for the rapid remanufacturing of the worm wheel single piece and small batch is provided.  
        关键词：Reverse engineering;Worm gear;Point cloud processing;Surface reconstruction;Three-dimensional model   
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        发布时间：2022-10-03
      • He Lin,Sanmin Wang
        Vol. 43, Issue 5, Pages: 18-22(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.004
        摘要：For the improvements of dynamical load stability of split torque-combine gear transmission， dynamical models of the system consisting of spur gears and herringbone gears is set up including excitations of multiple backlashes. The Gaussian elimination technique is introduced to deal with the elimination of extra rigid body displacements， ultimately， the dynamics equations are reduced to be 9 degrees of freedom. By applying the fourth order Runge-Kutta algorithm to solve the system dimensionless dynamical equations， dynamic load characteristic is analyzed under the excitations of backlash， general transmission error and time-varying mesh stiffness. The results show that dynamic load factor happens to jump to 2.705 under the backlash excitation， load sharing characteristic keeps very similar on the same stage when general transmission error varies， the dynamic characteristic vibrates severely on split torque gears while the perturbation factor of time-varying mesh stiffness is larger than 0.25， the investigation will provide a guidance for dynamic load design of this typical gear system.  
        关键词：Split torque-combine power gear transmission;Gaussian elimination;Backlash;Dynamic load characteristic   
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        发布时间：2022-10-03
      • Yansong Liu,Jujiang Cao
        Vol. 43, Issue 5, Pages: 23-27(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.005
        摘要：Crank group mechanism is a planar bar mechanism with over constraint. According to the characteristics of the mechanism， the static equilibrium equations of each motion component in crank group mechanism are established. And dynamic static force analysis model of crank group mechanism containing any crank is established based on deformation coordination equation from the axial deformation of the crank. A numerical example is given to illustrate the effectiveness and convenience of the method. Influence of different arrangement of crank on the force of crank group is analyzed， taking crank group mechanism with 3 cranks as an example. The results show that the maximum force peak of crank group mechanism can be greatly reduced by the symmetrical arrangement of 2 driven crank on active crank for the crank group mechanism with 3 cranks. The analysis provide a theoretical basis for the structural design and size selection of crank group mechanism， and lay the foundation for further study of factors affecting force.  
        关键词：Crank group mechanism;Force analysis;Deformation compatibility condition;Crank arrangement   
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        发布时间：2022-10-03
      • Yabo Zhou,Youqiang Wang,Cong Wei,Shenwen Long
        Vol. 43, Issue 5, Pages: 27-31(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.006
        摘要：Considering the slipping boundary conditions， the limiting shear stress model and the line contact elastohydrodynamic lubrication model are established， the lubricant interfacial slip velocity is deduced and the fluid-lubricated Reynolds equation is modified. The lubrication state of the journal bearing after interfacial modification is explored. Firstly， the change of the lubrication state of the bearing in the entire contact zone after the modification on both the bearing and the journal interface is analyzed. Secondly， the influence of the modification on either the bearing or the journal is studied respectively. Finally， the influence of modification on the friction coefficient of the bearing， and the change of friction coefficient with load and speed is discussed. The results show that under the condition of elastohydrodynamic lubrication， when the interface both the bearing and the journal are modified at the same time， the oil film will form a dimple in the inlet area and collapse in the outlet area； when the shaft interface is modified， the depression will be formed in the entire contact area and the corresponding pressure will increase accordingly. On the contrary， when the interface of the bearing pad is modified， the thickness of the oil film is reduced and the pressure is reduced. After the surface modification treatment， the friction coefficient decreases with the increase of load and velocity.  
        关键词：Slipping;Limiting shear stress;Journal bearing;Interfacial modification;Dimple   
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        发布时间：2022-10-03
      • Qiliang Wang,Hongwei Cui,Zisheng Lian,Long Li
        Vol. 43, Issue 5, Pages: 32-37(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.007
        摘要：In order to investigation the distribution characteristic of stress field of friction pairs in hydro-viscous drive during soft start-up process， Abaqus software is used to establish a three-dimensional thermal elastic analysis model of friction pairs. The indirect coupling numerical analysis method is adopted to predict the transient characteristics of stress field. In addition， the sensitivity of parameters is analyzed. The research results show that the thermal stress of the steel disc increases gradually during soft start-up process and reaches the maximum value at the end of the start-up process. And the position of the maximum value gradually approaches the central area. The oil grooves provide a good cooling effect and the maximum thermal stress of the friction lining appears at the edge of each rhombic region. The elastic modulus and thermal expansion positively impact the stress. Conversely， the thickness and Poisson's ratio negatively impact the stress. But the variance of parameters has no effect on the location of the maximum thermal stress. The analysis results provide reference for selecting the structural and material parameters of friction pairs.  
        关键词：Hydro-viscous drive;Friction pair;Transient thermal stress;Parameter sensitivity   
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        发布时间：2022-10-03

        Design· Calculation

      • Shuangshuang Zhang,Hongtao Yang,Qigeng Liu
        Vol. 43, Issue 5, Pages: 38-43(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.008
        摘要：The end stiffness characteristic of the mechanism has great influence on its positioning accuracy， compliance character and dynamic properties. In order to eliminate the configuration singularity， as well as to enhance its stiffness and accuracy， better dynamic property， a controllable stiffness of the mechanism is often required to satisfy different situations. On basis of full degree of freedom parallel mechanism， the design method by adding redundant actuated limbs to realize the end stiffness requirement is analyzed. According to screw theory， the inverse Jacobian matrix of parallel mechanism with limb single drive is analyzed， the mapping relationship matrix from the actuation to the end-effector stiffness is established. Then， the superposition rule of stiffness of each limb to the end stiffness component of the mechanism is analyzed. According to the end stiffness requirement， a stiffness synthesis method by adding redundant-actuated limbs to realize the end stiffness requirement is established. Finally， the Stewart parallel platform is adopted to verify this synthesis method， the design requirement of the end stiffness matrix decoupling is realized.  
        关键词：Stiffness synthesis;Redundant actuation;Parallel mechanism;Stiffness decomposition   
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        发布时间：2022-10-03
      • Zhong Feng,Huaping Chen,Guanhua Feng,Xiaogang Liu,Jianjun Liu
        Vol. 43, Issue 5, Pages: 44-46(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.009
        摘要：The difference between the planetary differential mechanism and the planetary closed differential mechanism is analyzed by examples of planetary transmission mechanism. The evolution process of RV reducer from one tooth differential cycloid needle wheel reducer is analyzed，the concept that the crank shaft is a negative 1 tooth sun wheel in a tooth differential meshing drive is proposed and the transmission ratio equivalent calculation is carried out. The power flow diagram of RV reducer is equivalent，and the transmission power distribution ratio formula of each branch is obtained，and the essence of planetary closed differential motion of RV reducer is revealed. This theoretical analysis is instructive for the forward design of the RV reducer.  
        关键词：Planetary closed differential;Power flow;Transmission ratio;Equivalent mechanism   
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        发布时间：2022-10-03
      • Zhao Wang,Xinping Wang,Jiexin Zhang
        Vol. 43, Issue 5, Pages: 47-51(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.010
        摘要：There are many types of planetary gear trains， and each one corresponds to a transmission ratio calculation formula， which makes great difficulties in the comprehensive research of planetary gear trains and the development of general design software. According to the structural diagram of the planetary gear train， the corresponding adjacency matrix is written. Then， the basic loop of the train is searched from the adjacency matrix to construct the basic loop matrix. Finally， the basic loop matrix is transformed into the coefficient matrix of the equation of motion. And use MATLAB to automate this algorithm and solve the equation of motion to obtain the gear ratio of the planetary gear train.  
        关键词：Planetary gear train;Graph model;Adjacency matrix;Fundamental circuit;Transmission ratio   
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        发布时间：2022-10-03
      • Yan Wang,Lubin Hang,Zhe Liu,Yong Chen,Siling Wang,Qiansheng Wang,Mingyuan Wang,Lele Bai
        Vol. 43, Issue 5, Pages: 52-56(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.011
        摘要：The automobile door lock is an important accessory for the car body， and its operability and reliability are related to the safety and performance of the car. Aiming at the new requirements of the new car door opening function in the future， the existing car side door lock is taken as the research object， and a transmission kinematic chain that can realize the electric unlocking function is proposed. Aiming at the problem that the connecting rod transmission mechanism in the electric opening movement chain is matched with the rack drive during the unlocking movement， the desired trajectory of the theoretical contact point is a smooth curve as the target. Based on the single open chain method， a kinematic equation system with decoupling and descending characteristics is constructed. The continuous-optimization method is adopted， and considering the conditions of stable operation and reasonable size， the solution output point of the connecting rod meets the optimal size of the desired trajectory， which provides a reference for the development of the new automobile door lock motion chain.  
        关键词：Car coor lock;Connecting rod trajectory;Single open chain;Optimization-continuous method   
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        发布时间：2022-10-03
      • Yuegang Chu,Yun Peng,Hao Zi,Kunpeng Zhao,Aiping Song
        Vol. 43, Issue 5, Pages: 57-63(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.012
        摘要：A new type of Continuously Variable Transmission （CVT） with surface-contact friction transmission structure is presented， which is a discrete adjustable radius CVT. The relationship between the size parameters of the discrete adjustable radius pulley transmission structure and the transmission ratio is analyzed. The calculation formula of the critical friction force of the discrete adjustable radius pulley transmission is derived. It is verified that the discrete adjustable radius pulley has large torque transmission capability in theory. In addition， the rotational speed fluctuation analysis based on ADAMS is carried out， and the experimental device of the discrete adjustable radius CVT is built and tested. The results show that the speed fluctuation meets the transmission requirements of most equipments. The new discrete adjustable radius CVT has great development value， which has the characteristics of compact structure and reasonable design.  
        关键词：Discrete adjustable radius pulley;CVT;Critical friction force;Rotational speed fluctuation analysis   
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        发布时间：2022-10-03
      • Jie Yu,Chaofeng Ma,Naichao Guo,Kai Liu
        Vol. 43, Issue 5, Pages: 64-69(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.013
        摘要：Based on the lever method， the 2 planetary transmission schemes are sorted out， and the 2 planetary transmission schemes are analyzed. The 4 planetary hybrid transmission schemes are further synthesized according to the 2 planetary transmission schemes. On this basis， combined with the single switching principle， the arrangement of the 4 planetary rows joint elements is carried out. According to the plane graph decision theorem， combined with the 4 planetary row transmission scheme after the joint elements arrangement， the transmission scheme interference test is carried out， and finally the scheme of 4 planetary row transmission is obtained.  
        关键词：Lever method;Planetary transmission scheme;Hybrid;Plane graphics method   
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        发布时间：2022-10-03
      • Yaqi Jiang,Lizhong Xu
        Vol. 43, Issue 5, Pages: 70-75(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.014
        摘要：A kind of swing movable teeth transmission drive actuator with SMA（Shape memory alloy） is designed， and the working principle of this kind of actuator is described. According to phase change mechanism of SMA wires and coupled mechanical model of movable teeth drive， the output torque of the drive is deduced. For the specific situation， the general design method of the actuator is given. The effects of the mutual coupling parameters such as the swinging rod amplification coefficient and the eccentricity of the movable tooth on the output characteristics of the drive are investigated， and the optimal range of the key parameters is given. The ideas and methods for the optimization and output characteristic analysis of the movable teeth drive actuator with SMA are provided.  
        关键词：SMA;Movable teeth;Structural design;Output characteristic   
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        发布时间：2022-10-03
      • Jizhe Mao,Yongchao Yuan,Yanjun Cao,Kun Zhang,Li Yu,Haiming Gang
        Vol. 43, Issue 5, Pages: 76-83(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.015
        摘要：The high speed gear rotor is widely used， and its dynamic property affects the stability and reliability of gearbox. The dynamic analysis of two kinds of high-speed gear rotor with abnormal vibration are proceeded by Romax software， the each nature frequency of two rotors and the influence of the bearing supporting parameter on each nature frequency are obtained. It is found that the running speed of first two high speed gear rotor before improvement is approached to the first order critical speed. At the same time， the shaft system structure is improved in the Romax to make sure the running speed faraway from critical speed. The improved test result indicates that the each vibration index is normal， and the running condition of gearbox is pretty well. A method for accurate calculating the critical speed of high-speed gear rotor is provided.  
        关键词：High-speed gear rotor;Dynamic analysis;Nature frequency;Romax;Critical speed   
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      • Hao Zi,Yun Peng,Yuegang Chu,Yuhan Shen,Aiping Song
        Vol. 43, Issue 5, Pages: 84-90(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.016
        摘要：On the basis of analyzing the characteristics of the current measuring technology of worm wheel and worm， a non-contact measurement based on laser displacement sensor and corresponding calculation method of tooth profile and pitch deviation were put forward. A comprehensive measuring device for worm wheel and worm is built to realize the collection of non-contact data. Through the comparison and analysis of the ideal tooth profile model of the worm and worm and the smoothing curve of the fitting point， the deviation of tooth profile and pitch are obtained. Through this method， the measuring process of worm wheel and worm can be effectively simplified and the accuracy and efficiency of measurement can be improved.  
        关键词：Worm and worm wheel measuring;Laser displacement sensor;Deviation analysis;Non-contact measuring   
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        发布时间：2022-10-03
      • Guanghui Yin,Lü Hongzhan
        Vol. 43, Issue 5, Pages: 91-95(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.017
        摘要：Heliostat transmission system of solar power tower requires high precision but conventional transmission can’t meet such precision. A harmonic drive with short flexspline is developed， which makes full use of the advantages of high precision of harmonic drive and combines the characteristics of zero teeth difference type output mechanism and harmonic drive. Based on statistics and probability theory， transmission error is calculated and the sensitivity of error of parts is analyzed with the Monte Carlo method. The results show that the transmission precision can meet the requirements of the heliostat and the flexible wheel and the output rigid wheel have the greatest influence on the transmission precision. Meanwhile， the developed harmonic drive device has smaller length to diameter ratio than the traditional harmonic drive and it realizes the miniaturization of its volume.  
        关键词：Heliostat;Harmonic drive;Transmission precision;Zero teeth difference   
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        发布时间：2022-10-03

        Test·Analysis

      • Peng Xiao Tiyi Liu Tao Zhang Junfu Peng
        Vol. 43, Issue 5, Pages: 96-100(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.018
        摘要：Gears are important components of mechanical products and its motion accuracy directly affects the quality and reliability of machinery. The influence factors of gear transmission accuracy include gear manufacturing， assembly errors and external loads， all of which are stochastic. Therefore， it is an important way to improve the motion accuracy of gear transmission by reliability analysis and design under the uncertainty design theory. In order to carry out reliability analysis of gear transmission accuracy， a torsional vibration model of a pair of gear is established with transmission error excitation，stiffness excitation and external load. Then， the four order Runge-Kutta method is used to solve the dynamic response of gear transmission， BP neural network is applied to build the input-output relationship model of dynamic system and motion accuracy reliability model of gear transmission system is then created. Finally，the first-order reliability method（FORM） is used to solve the motion reliability of the transmission system. The results show that the manufacturing and assembly errors are important factors affecting the reliability of the kinematic accuracy of the driving mechanism，which should be fully considered in the design and manufacture of gears.  
        关键词：Gear transmission;Dynamic kinematic accuracy;Reliability;Sensitivity   
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        发布时间：2022-10-03
      • Shenwen Long,Youqiang Wang,Yabo Zhou,Cong Wei
        Vol. 43, Issue 5, Pages: 101-105(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.019
        摘要：In order to solve the problem of resonance and sound in the running process of water lubricated rubber stern bearing， the dynamic response analysis of stern bearing is carried out based on ANSYS finite element analysis platform. Firstly， the low order natural frequencies and modes of stern bearing are obtained by modal analysis. Secondly， the response rule of the stern bearing with the frequency change is obtained by using the harmonic response analysis， so the natural frequencies which affect the dynamic characteristics of the stern bearing are determined. Finally， the sensitivity analysis of the structural parameters is carried out， and the influence factors of the vibration characteristics are sorted， the basis for reducing the experimental cost and the dynamic design of stern bearing is provided.  
        关键词：Water lubrication;Stern bearing;Harmonic response;Sensitivity   
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        发布时间：2022-10-03
      • Tong Guan,Honghai Xu,Xiongwei Xie,Linghui Wei
        Vol. 43, Issue 5, Pages: 106-109(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.020
        摘要：Based on the working principle of RV reducer， the combined， modular transmission efficiency test platform and its measurement and control system and software system that can meet the installation requirements of RV reducer with different specifications are designed and developed. The transmission efficiency test is carried out on the RV-40E prototype independently developed by orthogonal test method. The test data is analyzed by variance and variance. The results show that the factors affecting the transmission efficiency of the RV reducer are the interaction of output torque， input speed and output torque. Input speed， output torque is a significant factor， and the rest are non-significant factors.  
        关键词：RV reducer;Test platform;Transmission efficiency;Orthogonal test   
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        发布时间：2022-10-03
      • Cong Wei,Youqiang Wang,Yabo Zhou,Shenwen Long
        Vol. 43, Issue 5, Pages: 110-115(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.021
        摘要：In order to study the meshing thermal characteristics of the differential bevel gear under differential conditions， based on the thermal elastohydrodynamic lubrication theory， an unsteady thermal elastohydrodynamic lubrication model of straight bevel gears is established， and the temperature field of planetary gear is analyzed under differential condition. Firstly， the thermal characteristics of planetary gear and half-shaft gear under non-Newtonian fluids are studied. Secondly， the temperature field changes of planetary gear under differential conditions are studied with different tooth width and modulus. Finally， the temperature field variation of planetary gear with different rotational speed is studied. The results show that the temperature distribution of planetary gear across tooth width direction is different， the maximum temperature of the planetary gear body increases with the increase of tooth width， and decreases with the increase of the modulus. The temperature of the contact area between differential planetary gear and half-shaft gear increases as the rotational speed increases. This study provides a theoretical basis for the design of differential bevel gear lubrication.  
        关键词：Differential condition;Non-Newtonian fluid;Thermal characteristic;Temperature field;Rotational speed   
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        发布时间：2022-10-03
      • Kening Zhai,Jianjun Yang,Jidong Gao,Shuangxi Liu,Yazhuo Niu,Xianfeng Zhang
        Vol. 43, Issue 5, Pages: 116-121(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.022
        摘要：In order to obtain the potential of the speed ratio parameter optimization of a CVT vehicle on the direct improvement of fuel economy， the first step is to obtain the distribution characteristic of engine operating condition from test data in the NEDC cycle， most of the operating conditions are located in the urban cycle are below the optimal operation curve（OOC）. Then，the area that can be optimized is evaluated according to the speed ratio control method， there is 7% of the engine operating condition in the urban cycle can be optimized，in some working conditions in the suburban cycle（when the vehicle speed is up to 70 km/h and 100 km/h）， it cannot be optimized and adjusted due to the speed ratio limited value of the CVT. According to the simulation results， only the speed ratio parameters of CVT transmission are adjusted， including adjusting some operation conditions to the optimal fuel economy curve， or optimizing in all area， or enlarging the speed ratio range of CVT transmission， and the direct contribution of the maximum fuel saving potential reaches 3.12%.  
        关键词：Fuel economy;CVT;Speed ratio control;Simulation analysis;Optimization potential   
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        发布时间：2022-10-03
      • Jianguo Li,Ruiliang Zhang,Zhiyu Zhang
        Vol. 43, Issue 5, Pages: 122-125(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.023
        摘要：Taking the double arc gear as the research object， four pairs of gears with the same parameters produced under the same manufacturing conditions are tested and analyzed by different heat treatment processes， the effect of different manufacturing processes on gear performance is studied. Three loading schemes are used to study the fatigue characteristics of gear under two conditions of nitriding and unnitriding. The result show that the service life of the test gear treated with nitriding technology is about 2 times longer than that of the gear without nitriding under normal operating conditions.  
        关键词：Double arc gear;Gas nitriding;Fatigue analysis   
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        发布时间：2022-10-03
      • Wei Zou
        Vol. 43, Issue 5, Pages: 126-130(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.024
        摘要：Taking the external load distribution on sprocket wheel and meshing forces of planetary gear trains into account， the strength of case and the three-stage planet carrier assembly under three working conditions is analyzed by using Abaqus， comparison and analysis of three solutions of planet carrier and pins structure is carried out， and the accuracy of the FEA result is confirmed， which provides the basis for subsequent design and manufacture.  
        关键词：Gearbox;Strength of assembly structure;Structure of planet carrier and pin   
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        发布时间：2022-10-03
      • Jianzhong Zhang,Guanghao Zhang,Huazeng Hu,Feng Li
        Vol. 43, Issue 5, Pages: 130-133(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.025
        摘要：By analyzing the structural characteristics of the ankle joint， and aiming at the status of the existing ankle joint rehabilitation mechanism， a 3-UPS/S parallel rehabilitation mechanism is proposed. The mechanism has three degrees of freedom rotational function， which can complete the training of three modes of ankle joint extension/toe flexion， varus/valgus， internal rotation/external rotation respectively. Firstly， the degree of freedom is analyzed by using the spiral theory. The inverse solution equation of the mechanism position is established by using the D-H method. The theoretical value of the position inverse solution is calculated by using Matlab programming， and the position reverse solution simulation analysis is carried out by using ADAMS to verify the correctness of the inverse solution of the D-H method.  
        关键词：Rehabilitation mechanism;Kinematics;Ankle joint   
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      • Hong Zhang,Panpan Li,Tongde Wang
        Vol. 43, Issue 5, Pages: 134-140(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.026
        摘要：In order to improve the motion accuracy of the parallel mechanism， the influence of the flexible deformation produced by the branched chain on the motion trajectory of the 3T isotropic parallel mechanism during the movement is studied and summarized. Firstly， according to the structure of the parallel mechanism， its kinematics characteristics are analyzed. Secondly， by using the elastic dynamics model of the space beam element， the Lagrange equation， the finite element theory and the kinematics and dynamics constraints of each branch chain， the elastic dynamics equations of the three branches are established under the flexible deformation condition， and the solution is solved based on the Newmark method. Finally， the ANSYS and ADAMS software are used to carry out the elastic dynamics simulation of the parallel mechanism. Through the comparison of the theoretical value and the simulation value of the mechanism model， it is found that the three branched chains have an important influence on the kinematic characteristics of the 3T parallel mechanism under the flexible deformation conditions， and further prove the reliability of the elastic dynamics model of the parallel mechanism， which provides an important theoretical basis for the future research and application.  
        关键词：3T parallel mechanism;Flexible deformation;Lagrange equation;Finite element;Elastic dynamics;Newmark method   
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        发布时间：2022-10-03
      • Jun Lei,Manli Li,Chengda Wang,Heng Wang
        Vol. 43, Issue 5, Pages: 141-145(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.027
        摘要：Because of the complex vibration caused by various excitations， the transmission is not only related to driving comfort， but also has an important influence on the life and reliability of the transmission system. Considering the excitation source of the transmission and the mode of internal parts and external shift control can effectively improve the vibration problem of the transmission in the early design and development stage. Through a case analysis of mechanical transmission gear early abnormal wear and tear caused by the shifting handle jitter， it is deduced that the shaft assembly and balance block are resonant due to the excitation of the main reduction gear based on the vibration characteristics. The improvement strategy are proposed and verified by experiments.  
        关键词：Shift handle jitter;Vibration characteristic;Excitation;Resonance   
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        Development·Application

      • Bo Qin,Heng Yin,Zhuo Wang,Jianqiang Zhang,Zhijun Li,Jianguo Wang
        Vol. 43, Issue 5, Pages: 146-151(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.028
        摘要：According to the nonlinear and non-stationary of the planetary gearbox vibration signal fault characteristics is difficult to extract and the problem of low classification accuracy Gaussian kernel extreme learning machine based on random generation kernel parameters， a method for identifying the state of planetary gearboxes with enhence multi-scale permutation entropy （EMPE） and nuclear-polarized Gaussian kernel extreme learning machine （KELM） is proposed. Firstly， noise reduction of vibration signals of planetary gearbox planetary gears by morphological average filtering and using EMPE to obtain permutation entropy values at multiple scales to constructing eigenvector set. Secondly， kernel parameter σ of Gaussian kernel extreme learning machine is optimized by kernel polarization. Finally， using the EMPE eigenvector set as input， the planetary gear state identification model is constructed by the training of KP-KELM algorithm. The experiment results show that， compared with the fault classification model based on SVM and KELM， the EMPE and KP-KELM planetary gear fault diagnosis method has higher classification accuracy and stronger generalization ability.  
        关键词：Planetary gearbox;Multi resolution feature extraction;Kernel parameter optimization;State identification   
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        发布时间：2022-10-03
      • Jingcai Li,Junfang Ma,Wenli Xu,Jia Man
        Vol. 43, Issue 5, Pages: 152-155(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.029
        摘要：When the special chamfering machine is widely used to chamfering currently chamfer the end face of spiral bevel gears in the domestic， the adjustment of the grinding wheel is complex， the preparation time is long and the precision is difficult to guarantee. A machining process by using the special chamfering tool to control the movement of the cutter along the designed tooth profile trajectory on a milling machine is proposed， the quality of the chamfering can be ensured， and the material handling is not needed， the personnel is saved. Based on the Kimos software， the design of this kind of tool and the chamfering processing are carried out， and a concrete design example is given.  
          
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      • Man Cheng,Cheng Qiu,Jinfeng Li,Jincai Zhang,Wang Zhang,Nan Feng,Xianjin Shi
        Vol. 43, Issue 5, Pages: 156-160(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.030
        摘要：Aiming to the demand for the fatigue life test of robot reducer， based on the fatigue life test method， a fatigue life test device is developed. The key parts of the test device are analyzed， and the test verification is carried out. Compared with the continuous rotary fatigue life test device， the test device adopts the inertia load of reciprocating swing， the actual working condition of the robot can be simulated， accelerated fatigue life of the precision reducer can be conducted efficiently and accurately， and the test precision is high， cost is low.  
        关键词：Robot reducer;Fatigue life;Inertia load;Test device   
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      • Fugang Li Chengchen Zhuo Ran Li Yongkui Yang Yang Wang
        Vol. 43, Issue 5, Pages: 161-166(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.031
        摘要：In view of the high temperature of high speed shaft bearing， which often occurs in the speed increase gearbox of MW-class wind power， which causes the wind turbine fail to work normally， taking the gearbox with high temperature problem of high speed shaft bearing as the research object， the design analysis is carried out. Three factors affecting the high temperature of bearing are found， that is friction power loss of bearing Pbj， power consumption of lubricating oil Piol and air temperature in engine room Tc. Then， three factors are analyzed in detail to find the corresponding preventive measures. At the same time， the analyzed high temperature factors are used to check the high temperature unit of high speed shaft bearing in the operation of wind field. Finally， it is found out that the high temperature reason of bearing is the small clearance of bearing.  
        关键词：Wind turbine;Gearbox;Bearing high temperature;Bearing clearance;Friction moment;Lubrication system   
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      • Qiliang Wang,Xinwen Chen,Xiaofen Ye
        Vol. 43, Issue 5, Pages: 167-171(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.032
        摘要：Backlash is an important factor affecting the accuracy of the transmission system of the precision reducer. There are many tolerances which effect reducer backlash， if these tolerances are not differentiated and arbitrarily combined， there may be a risk of exceeding the range of the deviation. The traditional probability method used in the tolerance analysis is only based on the calculation which the tolerance meets the normal distribution， and most of these tolerance analysis are aimed at the specific type of transmission system. Based on the equal probability sampling， Monte Carlo simulation is applied to the grouping matching optimization of transmission system tolerance. The limitation of tolerance distribution type and transmission system type are overcome. Combined with an example， it shows that this method achieves the purpose of improving the precision of the precision reducer and reducing the cost.  
        关键词：Precision reducer;Backlash analysis;Monte Carlo simulation;Tolerance grouping;Equal probability sampling   
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        发布时间：2022-10-03
      • Jinku Li,Wei Liu,Liangrong Li
        Vol. 43, Issue 5, Pages: 172-175(2019) DOI: 10.16578/j.issn.1004.2539.2019.05.033
        摘要：Taking the flexible pin of planetary gear train of the first stage of 3.X MW wind turbine gearbox as study object， a finite model that considering gear mesh，bearing and bolt preloading is built. The stress and the displacement of the planetary gear train under rated working conditions are analyzed. The clearance change between the elastic pin sleeve and the limited block and the maximum displacement of the pin shaft are calculated. The results show that the clearance of the sleeve and the limited block is decreased 0.285 mm， but not touched， the maxium displacement of flexible pin is 0.24 mm. And the mean load factor （kγ） and the gear trace load distribution factor （KFβ） based on the gear ring root stress distribution are calculated， the mean load test of this 3.XMW wind turbine gearbox is carried out. The comparison results show that， the mean load factor of FE result is well matched to the practical situation， and this flexible pin has a perfect mean load performance.  
        关键词：Wind turbine gearbox;Flexible pin;Mean load factor;Mean load test   
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