最新刊期
期 9 ， 2020
- 摘要：Aiming at the development requirements of large load capacity and long life of wheel-side deceleration system， a logarithmic modified composite roller movable tooth transmission is proposed. Combined with the current research on the contact deformation of hollow roller， a method for calculating the meshing deformation of logarithmic modified composite roller is proposed by introducing design parameters Δc and Δe. The influence of filling degree and different rollers on meshing stiffness is analyzed. The finite element method is used to compare and analyze the equivalent stress distribution of different rollers. The results show that under the same load conditions， the meshing stiffness of the logarithmic modified composite roller movable tooth is slightly higher than that of the hollow roller， and the meshing stiffness decreases with the increase of the filling degree. The logarithmic modified composite roller can effectively improve the edge stress concentration and reduce the maximum equivalent stress.关键词：Movable tooth;Composite roller;Logarithmic modification;Meshing stiffness;Filling degree
- 4
- |
- 3
- |
- 0
发布时间：2022-11-02 - 摘要：A mathematical model is established to machine spiral bevel gears by duplex helical method. Based on the meshing principle of the gear， the digital representation of the spiral bevel gear tooth surface processed by the double helix method and the construction of discrete tooth surface points are completed， and the influence degree of each machine parameter error on tooth surface topology structure are analyzed. The correction model of tooth surface is built， through numerical example verification， the results show that tooth surface deviation is reduced effectively.关键词：Spiral bevel gear;Duplex helical method;Mathematical model;Tooth surface topology;Correction of tooth surface deviation
- 3
- |
- 3
- |
- 0
发布时间：2022-11-02 - 摘要：Gear whine noise of one hybrid power system is analyzed and optimized. Based on test noise order analysis， the main noise source is found. The contact patch test also shows that eccentric load phenomenon is obvious. The simulation and test results of contact patch are compared. It shows that the simulation results are coincident with test results， this simulation model could be used for the following micro parameter optimization analysis. The micro parameters of the first pinion gear are optimized. The contact patch of the optimized gear is more uniform， and transmission error is smaller， and the bearing dynamic responses are smaller. Noise test result shows that noise of gear micro modified became lower.关键词：Gear;Contact patch;Micro modification;Transmission error;Hybrid power system
- 5
- |
- 8
- |
- 0
发布时间：2022-11-02 - 摘要：Aming at the problem of correction algorithms of tooth profile errors of Oerlikon cycloidal bevel formate gear， by using the vector operation method， the geometric model of the tooth surface of gear is established. The method of tooth surface discretization is provided， and the coordinates and normal vectors of the discrete points on the tooth surface are calculated. Based on the principle of tooth profile error correction， the tooth profile error correction equation group is established based on the tooth profile error and inverse parameter sensitivity coefficient matrix between the actual tooth surface and the theoretical tooth surface. By using the Tikhonov regularization and L curve optimization algorithm， the linear equation group is solved， the correction value of the adjustment parameter of the machine tool is obtained. The software for tooth surface coordinate calculation and tooth profile error correction is developed by using Fortran. The correctness of the correction algorithm is verified by experiments and the maximum tooth profile error of the experimental workpiece is reduced from 37.5 μm to 5.2 μm.关键词：Cycloidal bevel gear;Machine tool adjustment parameter;Tooth profile error correction;Geometric modeling
- 5
- |
- 6
- |
- 0
发布时间：2022-11-02 - 摘要：A quadruped walking robot with a bionic horse configuration for equestrian-assisted treatment is presented. A single leg system of the robot with two driving degrees of freedom （DOFs） is driven by a cam-linkage combination mechanism， and it can adjust the span and height of the leg end-point trajectory. On the basis of introducing the structure and working principle of the quadruped bionic horse robot driven by a cam-linkage combination mechanism， the movement simulation of the robot is carried out. Using SolidWorks software to establish the bionic horse robot model and import it into Adams software for dynamics simulation. By motion planning to set a motor driving function， the walking movement of the bionic horse robot is realized. From the further analysis， the change law of the contact forces between the foot end and the ground， and the corresponding trend of the motion trajectory are obtained in the process of the leg lift and landing. Aiming at body jumping phenomenon occurring in the simulation movement of the bionic horse robot， a measures of variable driving laws for the motor are put forward to improve the body jumping. The relevant research provides theoretical support for optimization design and application of the robot.关键词：Quadruped robot;Bionic horse configuration;Cam-link combination mechanism;Motion simulation;Variable driving law
- 6
- |
- 4
- |
- 0
发布时间：2022-11-02 - 摘要：Based on the design concept of hybrid flexure hinge with large flexibility， an asymmetric hybrid flexure hinge with straight circle cycloid is proposed， and its mechanical characteristics are studied. Based on the bending theory of cantilever beam and Hooke's law under the micro element method， by selecting the appropriate integral variable and intermediate variable， the relatively simple calculation formula of rotational flexibility and tensile flexibility is obtained， and the general calculation formula of the maximum stress is given. The variation trend of rotational flexibility and maximum stress with parameters is discussed. The influence degree of structural parameters on rotational flexibility and maximum stress is compared. The results show that the maximum errors of the analytical expressions of rotational flexibility， tensile flexibility and maximum stress are within 5%， 7% and 5%， respectively. The rotational flexibility is inversely proportional to the elastic modulus， width and minimum thickness， and is directly proportional to the straight circle radius and arch height parameters， and is most sensitive to the change of the minimum thickness， followed by the width， and the arch height and straight circle radius are the weakest. The maximum stress is inversely proportional to the width， minimum thickness and the radius of the straight circle， and it is most sensitive to the change of the minimum thickness， followed by the width， and the radius of the straight circle is the weakest.关键词：Flexure hinge;Straight circle cycloid;Flexibility;Maximum stress;Sensitivity
- 4
- |
- 3
- |
- 0
发布时间：2022-11-02 - 摘要：According to the fault characteristics of the Main Drive System of the Annealing Kiln（MDSAK）， the nonlinear factors such as the time-varying meshing stiffness of the gear and the time-varying stiffness of the bearing are considered synthetically， the mechanical electrical coupling dynamics model of the MDSAK including the driving motor， the gear driving system and the load system is established. The influences of bearing outer ring fault and gear tooth break fault on the dynamic characteristics and electrical characteristics of the MDSAK are analyzed. The results show that when the fault occurs， the fault feature is to take the fault feature frequency of the shaft and gear where the fault occurs as the modulation signal， which produces the phenomenon of amplitude modulation and frequency modulation for the side frequency near the dominant frequency of each component， and also modulates the electrical signal. When the fault occurs in the bearing outer ring， the fault feature is to take the fault feature frequency of the outer ring as the modulation signal， which dominates each component. The side frequency around the frequency produces the phenomenon of amplitude modulation and frequency modulation， at the same time， it also modulates the electrical signal. The research results lay a theoretical foundation for the health monitoring and early warning of the MDSAK.关键词：MDSAK;Mechanical electrical coupling;Broken tooth fault;Bearing outer ring fault
- 4
- |
- 3
- |
- 0
发布时间：2022-11-02
Theory·Reserach
- 摘要：Aiming at the realistic problems on accurate calculation of time-varying meshing stiffness in the research of multi-stage helical gear dynamics， as well as its quantitative analysis of fluctuation value， a two-stage helical gear reducer used in an electric vehicle is taken as the object. Firstly， time-varying meshing stiffness of each gear pair are calculated based on potential energy method under different helix angles β， and the parameter τ which is determined by gear parameters such as the helix angle are also calculated. Quantitative analysis shows that the smaller the value τ， the smaller the stiffness fluctuation ΔK. Secondly， a dynamics model on a two-stage helical gear system with 12 freedom degrees is established to study the dynamic characteristics of the system under different helix angles. The results show that the dynamic performance of the system is good when the β is 15°， simultaneously， τ and ΔK of gear pairs at all levels are small. It verified the feasibility and accuracy of the prediction when using parameter τ to predict ΔK， and specifically when predicting dynamic performance of the gear system.关键词：Potential energy method;Time-varying meshing stiffness;Stiffness fluctuation value;Two-stage helical gear;Dynamics
- 4
- |
- 4
- |
- 0
发布时间：2022-11-02 - 摘要：The derivation process of the tooth surface mathematical model of the internal meshing spiral bevel gears for nutation drive is complex. In order to establish different tooth profiles of the spiral bevel gears and carry out load contact analysis， the general tooth surface mathematical model of the crown gear is established by using the general normal basic tooth profile. According to the meshing relationship between the crown gear and the external and internal spiral bevel gears， the general tooth surface mathematical model of the nutation spiral bevel gear is derived. Then the tooth surface models and three-dimensional models of the nutation spiral bevel gears with involute and double circular-arc as the normal basic tooth profiles are established. The load contact analysis of spiral bevel gears with high and low power and different tooth profiles is carried out by using the finite element software. The results show that the load has a great influence on the load contact characteristics of involute spiral bevel gear. The double circular-arc spiral bevel gear have the advantages of larger load capacity and more stable transmission compared with spiral bevel gear.关键词：General tooth surface model;Nutation drive;Spiral bevel gear;Involute;Double circular-arc;Load contact analysis
- 4
- |
- 3
- |
- 0
发布时间：2022-11-02 - 摘要：Based on AVL Cruise， the powertrain matching design and simulation for the direct drive scheme and the two-speed transmission scheme are carried out. According to the matching results， the two-speed transmission is structurally designed， including parameters calculation of key parts， static analysis and modal analysis. By comparing the current， the torque and the battery current of two schemes under various working conditions， the influence of the two-speed transmission on the economy and dynamic of the whole vehicle is clarified. The results show that， key parts meet the strength requirements under various working conditions and resonance is not occurred. The two-speed transmission scheme can reduce the demand for the drive motor torque and peak current， improve the system efficiency， which can improve the vehicle's economy and increase the driving range effectively. The related research can provide a reference for the selection of the electric vehicle power transmission system.关键词：Electric vehicle;Transmission;Parameter matching;Structural design
- 5
- |
- 3
- |
- 0
发布时间：2022-11-02 - 摘要：Aiming at the current application of electric power steering in medium-sized sweepers， in order to solve the problem of oversized motors and difficult applications， a new design scheme of variable transmission ratio transmission is proposed. Taking the electric power steering system of a certain model as an example， the transmission scheme of the steering gear used by the vehicle and the change of the output torque of the motor are studied. The mathematical model of the steering system is established， and the variable transmission ratio design parameters of rack and pinion are determined in combination with the operating conditions of the cleaning vehicle， and the calculation and contrastive analysis are carried out， the improvement effect of the scheme is verified. The new design scheme can directly reduce the output torque variation range of the assisted motor， reduce the selected motor power value， achieve the purpose of reducing the size of the motor， expanding the scope of application of the electric power steering system， and saving energy.关键词：Electric power steering;Variable transmission ratio;Sweeper;Scope of application;Energy saving
- 5
- |
- 3
- |
- 0
发布时间：2022-11-02 - 摘要：To solve the problem of market demand caused by population ageing， a multifunctional intelligent medical bed based on Maslow's hierarchy of needs is designed. According to the market investigation and data analysis， the driving and stopping function， posture changing function， man-machine operation interface and assistant physiological function are determined， and the corresponding mechanism is designed. Based on the Pro/E software， the 3D model of the medical bed is designed， the main mechanism is simulated and analyzed by Adams software， and the statics analysis of key parts of the intelligent medical bed are carried out by ANSYS software. The results show that the scheme of medical bed is feasible， the strength and stiffness conditions are satisfied， the parameter design is reasonable， and the ergonomics is satisfied.关键词：Intelligent medical bed;Structural design;Parameter design;Statics analysis
- 5
- |
- 3
- |
- 0
发布时间：2022-11-02 - 摘要：In order to realize the function that the flexible silicone isolator can automatically open along the preset track， a kind of supporting sleeve manipulator based on shear linkage mechanism is designed. The overall scheme of the support sleeve manipulator and the shear link mechanism are designed and studied， the kinematics equation of the shear link mechanism is established， the motion track of the center of mass of the support and grip rod is simulated， and the motion simulation is analyzed by using Adams software. Simulation results show that the designed braced manipulator can meet the trajectory output requirements， and there is no interference in the supporting process and the operation is stable， which lays a foundation for the optimization design of the support manipulator in the next step.关键词：Supporting sleeve manipulator;Shear link mechanism;Kinematics analysis
- 5
- |
- 3
- |
- 0
发布时间：2022-11-02 - 摘要：The principle of tooth surface generating of skew bevel gear is analyzed about spherical involute， based on the theory that the line which in the plane that is tangent with the base cone of the skew bevel gear roll on the cone surface absolutely， a new milling method of gear surface is put forward. In this method， the alignment line obtained by the vertical intersection of the edge end circle and the base plane of the disk milling cutter is the tooth surface generation line， the relative motion between tool and workpiece is realized by using the relative motion relation generated by tooth surface. By analyzing the tooth surface generation motion， the machining motion process model of the tool and the workpiece is established. The tooth surface cutting is realized by the way of three-axis linkage of machine tool. The device for cutting test of skew bevel gear is designed and the correctness and feasibility of the method are verified by cutting test.关键词：Bevel gear;Tooth surface generating line;Spherical involute;Milling method
- 3
- |
- 4
- |
- 0
发布时间：2022-11-02 - 摘要：As a bridge between manual operation and virtual surgical scene， the main manipulator can reproduce various laparoscopic surgical actions and plays an important role in the virtual surgical system. A main manipulator with a passive series connection structure is designed to suit the application requirements of the virtual laparoscopic surgery system. The forward kinematics model of main manipulator is obtained through kinematics operation， the main manipulator workspace and trajectory planning analysis is conducted in the Matlab software. Both qualitative and quantitative analysis of the kinematic performance of the main manipulator is carried out based on the location information collected by 3D electromagnetic tracking system. The results show that， the parameter design of the main manipulator is rational， the kinematics model of the main manipulator is correct， and the workspace analysis and the trajectory planning meet the needs of the virtual laparoscopic surgery， which lay the foundation for the virtual laparoscopic surgery system as well as the motion control and pre-operation plan of the main manipulator.关键词：Main manipulator;Virtual surgery;Kinematics;Workspace;Trajectory planning
- 3
- |
- 3
- |
- 0
发布时间：2022-11-02
Design· Calculation
- 摘要：In order to quickly and accurately evaluate the fatigue life of the planetary gear system of wind turbine， according to the distribution relationship between the input torque of the planetary gear system and the wind speed， the two-parameter weibull random load spectrum corresponding to different wind speed is compiled， and the load spectrum is statistically processed by rain flow counting method. The finite element analysis of planetary gear train in ANSYS is carried out to obtain its structural stress response. Based on Minner's linear cumulative damage theory and nCodeDesignLife， fatigue life is estimated. The fatigue life of the planetary gear train corresponding to the starting wind speed， the rated wind speed and the average annual wind speed of the wind turbine is emphatically analyzed， and the fatigue damage of each gear is obtained， which provided a theoretical basis for the design of the planetary gear train fatigue strength of the wind turbine.关键词：Planetary gear train;Two-parameter weibull distribution;Rain flow counting method;Fatigue life evaluation
- 7
- |
- 4
- |
- 0
发布时间：2022-11-02 - 摘要：When the working surface roughness of hydrodynamic sliding bearing reaches the same magnitude （micron） as the oil film thickness， the influence of surface roughness on the characteristic parameters of bearing cannot be ignored. In order to study the influence of roughness on the static characteristics of bearing， an experimental platform is built based on M2000 friction and wear testing machine to test the sliding friction pairs of 42CrMo steel， and a Reynolds mathematical model considering the surface roughness is established and solved. According them， the characteristic parameter of bearing capacity， friction resistance and friction coefficient of oil film with different surface roughness are obtained. The results show that with the increase of the load， the friction resistance become larger and friction coefficient become smaller， with the increase of the temperature of the inlet oil under the same load， the friction resistance become smaller and friction coefficient become smaller. The larger the roughness is， the larger the friction resistance and friction coefficient are.关键词：Dynamic bearing;Surface roughness;Bearing characteristic parameter;Reynolds equation
- 4
- |
- 5
- |
- 0
发布时间：2022-11-02 - 摘要：The existence of nonmetallic inclusions in gear materials can significantly reduce the contact fatigue strength of gears， and the research on the related mechanism can provide important guidance for the control of production quality and service evaluation. A finite element contact analysis model of gear pair with randomly distributed inclusions is established. Based on Brown-Miller multiaxial fatigue criterion， the influence of inclusion distribution characteristics on contact fatigue performance of gears is studied. The R-S-N curves of gear contact fatigue under three different reliability levels are predicted. The results show that， the presence of inclusions in the subsurface， especially the aggregation of inclusions， the considerable stress concentration will occur and the contact fatigue life will be significantly reduced. The minimum fatigue life depth is mainly in the range of 0.35bH to 0.75bH， and the statistical distribution is the most consistent with the logarithmic normal function， followed by the three parameter Weibull distribution function. The contact fatigue life conforms to the three parameter Weibull distribution better.关键词：Inclusions;Finite element analysis;Brown-Miller criterion;R-S-N curve
- 2
- |
- 3
- |
- 0
发布时间：2022-11-02 - 摘要：The solution and simulation analysis of the singularity configurations within its workspace of the seven axis cooperative KUKA manipulator is presented. Firstly， the manipulator kinematics model is constructed and the DH parameter is obtained. Secondly， the Jacobian matrix is computed based on screw theory and the screw reciprocity method is used to find the singularity configurations. Finally， the dexterity of end reference point of robot is analyzed based on manipulability index and the minimum singular value index by means of the Robotics Toolbox. The analysis results reveals that there are four singular conditions of the seven axis cooperative KUKA robot within its workspace， and the simulation results verifies the correctness of the analysis， and it lays a foundation for subsequent manipulator singularity avoidance arithmetic research.关键词：Modular manipulator;Jacobian matrix;Screw theory;Singularity
- 5
- |
- 4
- |
- 0
发布时间：2022-11-02 - 摘要：To study the lubrication performance of roller enveloping end face engagement worm drive， the elastohydrodynamic lubrication （EHL） model is established based on meshing theory of roller enveloping end face engagement worm drive and the theory of EHL. Based on calculation formula of approximate film thickness and film thickness ratio in every lubrication condition area， the simulation is conducted using Matlab software， and the time-domain distribution of lubrication condition， minimum film thickness and film thickness ratio are analyzed， it can be concluded as that this transmission pair has better lubrication performance. Finally， the influences of roller radius R and orifice coefficient k on lubrication performance of the transmission pair are analyzed. The results show that the roller radius R should not too bigger， orifice coefficient k should not too smaller， for effectively improving the lubrication performance of the roller enveloping end face engagement worm drive．关键词：Roller enveloping;End face engagement worm gear;Elastohydrodynamic lubrication;Lubrication performance;Minimum film thickness
- 5
- |
- 3
- |
- 0
发布时间：2022-11-02 - 摘要：In the aspect of root crack fault detection， the severity of damage can be compared by cepstrum analysis， but it is impossible to quantify the extent of damage. In order to realize quantitative detection of damage degree， the method of Principal Component Analysis （PCA） and Grey Relational Analysis （GRA） are combined to use. Firstly， the energy method is used to calculate the time-varying meshing stiffness of gear pairs with different root cracks and analyze the response of different damage degrees. Then， statistical indicators of damage detection are also combined to carry out quantitative detection. Through PCA algorithm， the dimensional reduction of the multidimensional statistical indicators of damage detection is optimized. The relational degree between the target sequence to be examined and each comparison state sequence is calculated. The degree of crack damage is characterized by relational degree. On the basis of theoretical simulation， experimental verification is carried out. The results show that cepstrum analysis can effectively identify the root crack fault. The higher the damage degree， the higher the peak amplitude of cepstrum. The relational degree of PCA and GRA combined algorithm is larger and the discrimination degree is more obvious than that of direct GRA calculation. The damage degree of the target will can be effectively quantified， the theoretical basis for quantitative identification of tooth root crack is provided.关键词：Tooth root crack;PCA;GRA;Failure identification;Damage detection
- 2
- |
- 3
- |
- 0
发布时间：2022-11-02 - 摘要：Through building the dynamics model of the wet dual clutch transmission， and analyzing the starting control strategy， a method of dynamically adjusting the starting target speed is proposed. Used vehicle jerk and sliding friction work as the evaluation criteria， the starting smoothness is improved when meeting the dynamic response of vehicle starting. A wet dual clutch transmission of GERTRAK is used for verification， the result shows this way can improve vehicle starting quality.关键词：Wet dual clutch transmission;Starting control;Jerk;Friction work;Smoothness;Experiment verification
- 3
- |
- 3
- |
- 0
发布时间：2022-11-02
Test·Analysis
- 摘要：The gear and rack drive devices are used to realize various movements of the stage in modern stage. Aiming at the problems of vibration and noise in the operation of rigid driving device， which affect the stability of stage motion and working environment， a sprocket chain plate driving structure is designed. The model of the driving device is established， and the driving system is simulated and dynamically analyzed， and the field test is carried out. The results show that the sprocket chain plate drive device has flexible effect， eliminates the defects of the rigid drive device， makes the stage transmission stable and reduces the noise. The driving device is applied in practical engineering， which proves the rationality of the design.关键词：Stage driving device;Gear and rack;Sprocket chain plate;Optimal design;Stage elevator
- 4
- |
- 3
- |
- 0
发布时间：2022-11-02 - 摘要：In order to reduce vibration and noise， the modification of the tooth profile of the planetary gear and the eccentric helix are studied. The influence of tooth profile modification，helix modification， helix modification factorⅠand helix modification factorⅡon transmission error peak difference， tooth surface maximum contact stress， tooth root bending stress of planetary gear and tooth root bending stress of half-shaft gear are analyzed respectively by KISSSoft. The regression equations of four response quantities are established by Minitab， and the optimal modification scheme is obtained under the condition of minimum transmission error peak difference， minimum contact stress on the tooth surface and the bending stress at the tooth root of the planetary gear is no more than 1 100 MPa. After modification， the peak difference of transmission error is reduced by 11.39%， the maximum contact stress of tooth surface is reduced by 3.89% and the bending stress of tooth root of planetary gear and half-shaft gear is reduced by 4.40% and 5.62% respectively. Finally， finite element simulation analysis is used to verify that the fatigue life of the modified differential gear meets the requirement， and the bench experiment is carried out to verify.关键词：Numerical simulation;Gear modification;Regression model;Multi-objective optimization;Fatigue life
- 3
- |
- 5
- |
- 0
发布时间：2022-11-02 - 摘要：A theoretical analysis of the forming defect in the hot rolling forming process of a hypoid gear wheel is performed. It is found that defects occur during the hot rolling process， such as “lugs”. The control variable method is used to carry on the numerical simulation test of hot rolling， the influence law of the speed of the mold， the feed speed of the mold， friction coefficient， temperature， etc on the rolling quality are studied. Through the analysis of the simulation process and the simulation results， the influence law of the process parameters on the roll forming is obtained， and the reasonable combination of process parameters is ultimately determined. The hot rolling bench experimental results show that the reasonable process parameter matching can indeed reduce the forming defects， such as lugs and uneven material flow.关键词：Hypoid gear;Hot rolling technology;Process setting;Forming rule
- 4
- |
- 3
- |
- 0
发布时间：2022-11-02 - 摘要：The surgical robots with remote motion center （RCM） play an important role in the field of minimally invasive surgery （MIS）. Considering the advantages and disadvantages of double parallelogram and double synchronous belt RCM mechanism， a new RCM mechanism based on single synchronous belt， single parallelogram is proposed. Based on Adams and SimMechanics， the accuracy and workspace of the fixed point at the end of the new RCM mechanism are analyzed. The simulation results show that the new RCM mechanism has higher fixed point accuracy， simple and compact mechanism and good stability on the basis of meeting the motion space required by the operation.关键词：RCM mechanism;Adams kinematics analysis;SimMechanics;Motion workspace
- 13
- |
- 4
- |
- 0
发布时间：2022-11-02
Development·Application
- 摘要：Aiming at the regenerative braking control problem of new energy vehicles， four basic regenerative braking control strategies， fuzzy control strategies， neural network control strategies， and the research status of comprehensive optimization control strategies based on the above control strategies are summarized. The hot issues of various control strategies in the stage of theoretical exploration are summarized. The analysis shows that the research on regenerative braking control strategy based on fuzzy control theory and integrating multiple intelligent algorithms has a good research prospect and engineering application potential.关键词：Regenerative braking control strategy;New energy vehicle;Energy recovery
- 10
- |
- 6
- |
- 0
发布时间：2022-11-02
Review
- Technical support is provided by Beijing Founder electronics co., LTD 豫ICP备05013835号-5
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0