最新刊期
期 6 ， 2016
- 摘要：Aiming to the spiral bevel gears and cycloid bevel gears,the universal mathematical model is established,and the tooth flank geometry comparison is carried out. Firstly,the two kinds of cutter head structure are analyzed,and the universal cutter head model is set up. Secondly,the cut motion and manufacture process for two systems are analyzed,and the universal mathematical model is established. On basis of solving the tooth flank,the tooth flank comparison for spiral bevel gears and cycloid bevel gears is carried out from aspect of tooth line spiral angle and tooth flank topology. This will provide theoretical guide for cycloid bevel gears rough cut by use of spiral bevel gear cutter.关键词：Spiral bevel gear;Cycloid bevel gear;Cutter head model;Universal mathematical model;Tooth flank geometry comparison
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发布时间：2022-10-20 - 摘要：In order to suppress the vibration in the end of large double-link hydraulic flexible manipulator,taking the heavy load hydraulic flexible mechanical arm as the study object and aiming at the end of arm movement in the process of vibration phenomenon,by the servo-hydraulic system-Euler Bernoulli model,Lagrange equation and Jacobian matrix,a piezoelectric feedback driven system control method is designed,through the end of the robot arm equipped with sensitive piezoelectric transmitter,piezoelectric actuators and inversion control design methods,the movement of servo hydraulic cylinder vibration,the hydraulic cylinder with manipulator friction and manipulator rod elastic vibration influence of the hydraulic flexible manipulator end vibration are studied. The simulation results show that,the vibration suppression method for better stability control,the end vibration of hydraulic flexible manipulator can be significantly reduced,the vibration attenuation time is shortened,the positioning precision can be improved obviously.关键词：Hydraulic flexible manipulator;Piezoelectric feedback driven system;Inversion control design methods;PPF control algorithm
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发布时间：2022-10-20 - 摘要：A new 3-PUPU parallel robot is proposed,its mechanism characteristic is introduced. The degree of freedom of the parallel robot end executor is analyzed based on the screw theory,and the kinematics model of the robot is established by using the three coordinate method. The kinematics analysis and research of the robot end executor are carried out by using analytical method. Finally,according to a group of examples and using MATLAB,the displacement,velocity and acceleration of the parallel robot end actuator are got,and the correctness of the theory inference is validated.关键词：Parallel micromanipulator;Screw theory;Method of three coordinates;Kinematics analysis
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发布时间：2022-10-20 - 摘要：The principle of the NC planing process of the spur face-gear is briefly introduced,the equations of the tooth profile and the tooth cutter are derived,the mathematical relation between the tooth cutter angle and the allowance is established,and then,the machining path of the NC planing of the spur face-gear is optimized. With the comparison result between the optimized machining path and the previous one,it is indicated that the proposed optimized method can shorten the feeding times by 50%. Finally,the optimized machining path is simulated in NC codes with the Vericut software,which shows that the optimized machining path method for the NC planing of the spur face-gear is feasible,efficient and can meet the precision requirement.关键词：Planning;Face-gear;NC planing machine;Rough machining
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发布时间：2022-10-20 - 摘要：The powder particles flow lubrication mathematical model is established. The thermal elastohydrodynamic lubrication of spur gears are investigated with considering quantitative influence of particles flow on oil rheological viscosity and density,reckoning in time-varying effect and thermal effect. The influence of different mass fraction of MoS2 on film pressure,film thickness and temperature are analyzed. The influences of synthetic diamond,45 steel,graphite and MoS2 with 5% mass fraction on film pressure,film thickness and temperature are compared. Finally,the comparative validation is carried out according to the existing experimental results. Results show that the noticeable increase in mass fraction of MoS2 may cause a slight reduction in the maximum temperature,a remarkable reduction in the minimum film thickness and a distinct reduction in contact centre transient temperature at pitch point. The graphite and MoS2 particles flow with low friction coefficient and low hardness have preferable lubrication effects. However,the synthetic diamond and 45 steel particles flow with high friction coefficient and high hardness are harmful to lubrication.关键词：Particles flow;MoS2;Spur gear;Elastohydrodynamic lubrication;Thermal effect
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发布时间：2022-10-20 - 摘要：It is important to meet drive requirements of the high precision,high speed and long-stroke for robotic driving system. An investigation on meshing force and contact stress of trochoid roller pinion rack transmission is carried out. Firstly,the mechanical model of meshing pair is established when considering statically indeterminate problem of multi-tooth meshing transmission,and the time-variant calculating formula and change of meshing force is derived,and force distribution between rollers is analyzed according to the equilibrium conditions of moment and the analysis of pressure angle. Then,the calculating formula and change of stress is concluded based on the Hertz formula of elastic mechanics and radius of curvature of the contacting point. Finally,a example is given and the finite element models of meshing pair are established. Through the finite element simulation of the meshing process of roller and trochoid tooth,the rationality of the mechanics modeling method and the analysis results of the meshing pair are verified.关键词：Roller pinion;Trochoid rack;Mechanical property;Hertz contact;Finite element
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发布时间：2022-10-20 - 摘要：A built-in solar azimuth tracking device is designed. Then,its 3D model of azimuth angle gear transmission system is established by using UG,the wind load and boundary conditions are determined.The finite element analysis of the gear transmission system is carried out based on the ANSYS Workbench simulation environment. Finally,the integral stress distribution condition and other important properties of the gear transmission system are obtained and verified by using the Hertz theory. The results show that the maximum stress of gear transmission system is 408. 29 MPa by finite element analysis and appear in the idler gear meshing,near the dedendum transition curve is obvious exist stress concentration,and the stress fluctuation on worm and gear is bigger. The contact strength of the tooth surface is analyzed and calculated by using the Hertz theory. The results are verified by the finite element method. This study can provide a certain reference and basis for the gear design and dynamic analysis of gear transmission system of two-axis tracking mechanism.关键词：Two-axis tracking devic;Gear transmission;Azimuth angle;Finite element method;Contact strength
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发布时间：2022-10-20 - 摘要：Aiming at lower accuracy of classification for signal feature extraction of rolling bearing,firstly,some time domain indexes for online simple rapid discrimination are selected. The sensitivity of time domain index of fault is analyzed based on size of bearing fatigue damage and number of local damage. Secondly,based on the traditional time domain index,two more sensitive time domain index ‘TALAF ’and ‘THIKAT ’is searched. Lastly,the data set including two new indicators are trained and tested based on wavelet neural network which has a good real-time. The training and testing results for the traditional time domain indexes kurtosis and BP neural network are compared with results of the data. The simulation results show that TALAF and THIKAT can effectively improve the accuracy of prediction index state bearing.关键词：Rolling bearing;Time domain index;Wavelet neural network;Fault prediction
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发布时间：2022-10-20 - 摘要：Taking the vibration of rear axle caused by bearing mounting distance of a mini car rear axle main reducer driving gear and driven gear as the research object,in order to optimize the impact of the bearing mounting distance of driving gear and driven gear on the vibration noise,and improve the service life of the bearing of the driving gear and driven gear. The different mounting distance at different speeds are analyzed by simulation respectively by 3D modeling and ADAMS dynamics simulation,the optimal installation distance is obtained,and through the test on the mounting distance,the vibration and noise reduction of the main reducer are greatly improved,and the bearing life is greatly improved. At the same time,it can provide a certain method guidance for the structure design and the vibration and noise of the main reducer of the mini car.关键词：Mounting distance;Adams;Bearing life;Noise and vibration reduction
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发布时间：2022-10-20 - 摘要：By using the multi-shift transmission system,the drivability and economy of electric bus could be improved,the requirement of motor performance is reduced and the diving range is extended. The AMT control strategy model of electric bus is built,the shifting control strategy is developed and the shifting schedule is optimized. By analyzing the motor characteristics,as well as the clutch performance evaluation in the process of starting and shifting,a control strategy of motor and clutch is developed based on Matlab / Simulink. A simulation model is built based on Cruise and shift schedules based on the principle of best power performance and best economy performance. The simulation result indicated that the control strategy is able to make the motor work in high efficient area and improve the operation efficiency of the motor.
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发布时间：2022-10-20 - 摘要：The gear after honing has many advantages,such as good tooth surface texture,smaller noise in transmission,high residual compressive stress and long lifetime etc. In the gear honing process,the relative speed which is between honing wheel and processing tooth surface determines honing process capacity and tooth texture. From the theory model of involute helicoid,the relative velocity formula at contact points when worm honing wheel and work piece are engaging is derived. By analyzing the change trend of relative velocity at contact points,the parameters of worm honing wheel which related to the change of velocity are found. According to adjustment of the parameters of number of thread and reference circle,the influence on the relative velocity is analyzed,then optimizing design of worm honing wheel is carried out.关键词：Involute worm;Gear honing;Relative velocity;Optimization design
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发布时间：2022-10-20 - 摘要：Based on the differential kinematics of parallel mechanism displacement vector differential mapping relation between input and output,through establishing a planar 3-RPR topology optimization model of fully compliant parallel mechanism（ SIMP interpolation model）,the solution is optimized by using the optimization criterion method（ OC） algorithm,and by using the Heaviside filtering technology,the checkerboard phenomenon is restrained and processed. Combining with quadratic interpolation method of topology optimization,the curve fitting of the model is carried out,and the 3D model is created in the Solidworks,the model is imported into Hyperworks for second meshing and its statics comparison and analysis are carried out,the results show that,the manipulator which based on the mapping relation of topology optimization not only has the same movement characteristic with the traditional parallel mechanism,but also the structure is more compact,lightweight,and the method provides a theoretical reference for the configuration synthesis of this kind of plane compliant parallel mechanism.
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发布时间：2022-10-20 - 摘要：An innovative robot is designed. It can move in omni-direction on flat floor with three degrees of freedom in plane,and is also able to passively overcome obstacles of up to 4 times of its wheel radius within the 45 degree slope range. By using rectangle configuration,the four Mecanum motorized wheels is arranged on a climbing structure on each side which is consisted by double cranks and spring coupling. In order to find the conditions of the system with four Mecanum wheels to move in omni-direction,the motion model of the general system is put forward and the inverse velocity Jacobian matrix is analyzed. Then six typical layouts of four Mecanum wheels are illustrated and the optimal layout is picked out by calculating the Jacobian matrix rank of the six typical layouts. The kinematic model of the climbing structure is built and its parameters are optimized. Finally,the functions of the robot system including straight movement,lateral movement,zero turning radius and overcoming obstacles are simulated based on the virtual prototype technology. A well functioning prototype is designed and manufactured,and its performance is excellent.关键词：New robot;Omni-directional Mobile;Obstacle crossing;Prototype
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发布时间：2022-10-20 - 摘要：According to the constrained length of the bars,the unconstrained optimization model is constructed to formulate the forward position analysis for a 6 degrees-of-freedom general 6-SPS parallel mechanism,and the differential evolution（ DE） algorithm is employed to solve this problem. Aiming at the basic DE algorithm has some weaknesses,such as evolutionary stagnation and falling into local extremum domains,an adaptive strategy for introducing new individuals is presented to improve its optimization performance. This strategy is dynamically incorporated into DE algorithm to form an adaptive DE（ ADE） algorithm,which adopts hybrid mutant operators,and scale and cross factors with trigonometric function perturbations. The numerical results of the forward kinematic analysis for a general 6-SPS parallel mechanism show that ADE algorithm can obtain all high accuracy solutions with lighter computational cost. Furthermore,the ADE algorithm is compared with basic DE,the adaptive mutation particle swarm optimization,and improved artificial bee colony algorithms,and it is verified that the former outperforms the compared algorithms in term of convergence precision and calculated robustness.关键词：Parallel mechanism;Forward position solution;Differential evolution algorithm;Adaptive strategy
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发布时间：2022-10-20 - 摘要：The double helical synchronous belt has received great concern for its high loading capacity,low transmission error and noise. Through the gear profile curve parameter analysis of synchronous belt and pulley,the gear profile equation is established by using the high order contact meshing theory. The mold gear surface profile processing characteristic is investigated and the mold surface equation of double helical synchronous belt is deduced according to the coordinate transformation and gear meshing principles. Finally,the combined detachable mold is proposed to manufacture four belts simultaneously. The proposed mold is used to guide the production practice.关键词：Double helical synchronous belt;Transmission error;Mold;Profile curve
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发布时间：2022-10-20 - 摘要：The torsional stiffness of gear pair transmission chain usually employed in rotary table plays an important role in both static and dynamic characteristics of machine tools. Taking the gear pair transmission chain as study object,considering the mesh stiffness of gear pair & torsional stiffness of shaft,a general mathematical model for torsional stiffness of gear pair transmission chain is established. Meanwhile,taking a two-stage transmission as example,the effectiveness of analytical model is verified by using the finite element software. Furthermore,the mathematical model for optimal design of transmission chain is constructed,a lightweight design of the transmission chain is carried out by considering the torsional stiffness constraint. The optimization results show that the volume is obviously smaller after optimizing under the premise that the torsional stiffness of transmission chain is guaranteed.
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发布时间：2022-10-20 - 摘要：The cross double-slider model is put forward to solve the defect of that continuous casting mold material area is rectangular,while the ordinary double pendulum rod type automatic mold flux feeder machine material area is sector,there is a blind zone of feeding. And the mathematical model of the cross double-slider model is established,the equation of cam contour curve is calculated,the reason of the dead center that the design based on the cross double-slider model is analyzed. On the basis of the above,the rectangular compensation technology of cam linkage combined mechanism is put forward,the virtual prototype of cam linkage combined mechanism is established,and the kinematics analysis of the virtual prototype is carried out. The speed curve of the center of outlet port of the feed tube is obtained,which provides the basis for improving the uniformity of the protection slag in the crystal. And the virtual prototype is analyzed,and the minimum transmission angle of mechanism is obtained,the feasibility of the design parameters of the virtual prototype is verified.关键词：Continuous casting mold flux feeder machine;Cross double-slider model;Cam linkage combined mechanism;Kinematics analysis
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发布时间：2022-10-20 - 摘要：The finite element analysis software ANSYS is applied to conduct the finite element analysis of the driving drum,and the stress and deformation conditions are obtained. According to the result,the structure redesign and lightweight research of the driving drum are carried out,and the lightweight results are verified.Finally,the multi-objective optimization design of the driving drum is carried out by using optimization module of ANSYS Workbench,which provides a theoretical basis for the optimization and improvement of the driving drum structure.关键词：Driving drum;Structure;Design;Multi-objective optimization
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发布时间：2022-10-20 - 摘要：Rod gear speed reducer and transmission is composed of linkage mechanism and meshing transmission. This transmission mechanism is simplified plane four-bar mechanism. On the basis of kinematics and geometry principle,the kinematics analysis of the mechanism is studied by means of matrix method. The corresponding kinematics equations are derived,including position,velocity and acceleration equations of rod and rockers. The computer simulation analysis is developed and the variation curve of main component angle displacement,angle velocity,angle acceleration and errors are figured by using MATLAB program language. This study laid a foundation for further analysis and optimization of the rod gear speed reducer and transmission.关键词：Rod gear speed reducer and transmission;Structure design;Kinematics analysis
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发布时间：2022-10-20 - 摘要：A flexible mechanical transmission mechanism for descaling machine is designed,which composes of gear transmission,chain transmission and flexible connection,the flexible degree of freedom movement for single input multiple output system is achieved by mutual component transmission. The process of transmission system design and function realization are detailed described,at the end,the dynamic damper performance of prototype is researched,the results show that the flexible mechanism of descaling machine overcomes rigid defects existing in the traditional pure mechanical system and makes design more full of elasticity and plasticity,which provides a new direction for mechanical transmission system design.关键词：Flexible transmission system;Flexible connection;Degree of freedom;Dynamic damper performance
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发布时间：2022-10-20 - 摘要：The mathematical model of optimization design of a mechanical press machine six-link mechanism is built according to the press machine technological requirements,constraint conditions and the optimization objective. By using software ADAMS / View,the optimization design model of the six-link mechanism is constructed,and the optimization design is completed. The result of the optimization design and the slider stroke curves and velocity curves show that the quick-return characteristics of the mechanism is improved by the optimization design and the requirement of the press stamping technology is meet.关键词：Press machine;Six-link mechanism;Optimization design;Adams
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发布时间：2022-10-20 - 摘要：The KANE dynamics equation of 6-PTRT parallel manipulator is derived according to the 6-PTRT parallel robot manipulator characteristic and pertinent literature. A tool in space surface processing trajectory is obtained by using quaternion form. The six degrees of freedom of the parallel robot is realized through space trajectory planning. The simplified strategy of the dynamics model is obtained to improve the operation efficiency by analyzing the influence of the moving parts on the driving force in middle and low speed and high speed machining. The cause of the fluctuation of the dynamic response curve of the mechanism is analyzed. In order to get a more smooth dynamic response curve,the Akima interpolation method is used to optimize the dynamic response of each branch,so as to improve the stability of the mechanism. The research provides the theoretical basis for the structure design,trajectory planning and real time control.关键词：6-PTRT parallel robot;KANE method;Simplified strategy;Akima interpolation method
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发布时间：2022-10-20 - 摘要：In order to analyze the influence of the engagement algorithm and structure parameter on the transmission performance of harmonic drive（ HD）,the involute tooth profile is used for the HD,an exact engagement algorithm and its approximation are obtained based on the envelope theory and the exact calculations for the rotation angles of flexspline（ FS）,moreover,the conjugate existent domain（ CED） and the conjugate tooth profile（ CTP） that based on the aforementioned algorithm are studied,furthermore,the influence of the wave generator（ WG） and the coefficient of radial displacement are researched here. The results demonstrate that two CEDs and double conjugated phenomenon are found,and the approximate algorithm,the coefficient of radial displacement,the WG have little effect on the CED,CTP,engagement deviation for the CED one,but obviously influence on the CED,CTP,engagement deviation for the CED two.关键词：Harmonic drive;Engagement algorithm;Parameter;Influence
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发布时间：2022-10-20 - 摘要：To solve the problem of freightage in the situation of walk-up building,a type of intelligent stair-climbing robot with a new-type walking mechanism is developed. It puts deformable wheel into use which apply three groups of crank rocker mechanism to realize the deformation association and achieve the purpose of climb stairs. Firstly,the design process of walking mechanism is illustrated in details. Secondly,through the simulation research,the rationality of the designed structure for deformable wheel is analyzed. Finally,the physical prototype is made and the climbing test is achieved,which testified the feasibility of the design.关键词：Stair climbing;Climbing robot;Walking mechanism;Deformable wheel
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发布时间：2022-10-20 - 摘要：The topology optimization design of the complicated transfer case housing is conducted by using the variable density method. Taking the minimum compliance as the optimization objective and the volume fraction,static displacement,static stress,modal frequency and machining process as constrains condition,the topology optimization analysis of external shape and internal rib plate are carried out. Then,the static strength and modal character analysis of the optimized transfer case housing are carried out. The analysis results demonstrate that the static strength and modal frequency are higher than the design objective,the topology optimization design of complex housing structure is realized.关键词：Transfer case;Housing;Topology optimization;Finite element analysis
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发布时间：2022-10-20 - 摘要：A novel fully-decoupled three-translational and one-rotational（ 3T1R） parallel robot mechanism is proposed. First,the degree of freedom analysis and instantaneous analysis of the parallel mechanism is carried out by using the screw theory and the correctness of the configuration method is verified.Through the analysis of the relationship between input and output of mechanism,the Jacobian matrix of the parallel mechanism is obtained and it is 4 × 4 order diagonal matrix. The fully-isotropic and fully-decoupled characteristics of the mechanism are proved. And this mechanism control is simple and has good movement and force transmission performance and higher practical value.关键词：Degree of freedom;Parallel mechanism;Fully-decoupled;Fully-isotropic
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发布时间：2022-10-20 - 摘要：In order to rationally allocate modification coefficients of a series gear mechanism,a optimization model based on multi-objective genetic algorithm is set up. In the model,the objectives are set as the center distance deviation and variation coefficient of addendum height,and four constraint conditions are taken into account,such as no undercutting,no too thin addendum thickness,no too small contact ratio,no transitional curve interference. A multi-objective genetic algorithm,namely NSGA-Ⅱ method is used to solve the objective function. The modification coefficients of the series gear mechanism are optimized. As the results show,this method is especially efficient to be used to optimize the mechanism modification coefficients. The optimized coefficients accord with engineering practice and fulfill well the design demand.关键词：Gear;Modification coefficient;Multi-objective optimization;Genetic algorithm
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发布时间：2022-10-20 - 摘要：Aiming at the Gear vibration signals have the nonlinear and non-stationary characteristics,to avoid the disadvantages of traditional time and frequency domain method in the characterization of the state of equipment and failure identification model "less learning"problem caused by small sample size,the gearbox fault diagnosis method based on kurtosis and intrinsic mode function（ IMF） energy feature and least squares support vector machine（ LS-SVM） is proposed. Firstly,by using ensemble empirical mode decomposition（ EEMD）,the collected gear vibration signal is decomposed,on this basis,the IMF components which contain major fault information are extracted and its energy feature and kurtosis are calculated,and the time-frequency domain two kinds of the feature vector are constructed. Secondly,taking the fusion feature vectors of three conditions of normal,the root crack and broken as input,the gearbox fault type identification is conducted based on the LS-SVM. The experiment results show that the gear working state can be accurately identified by this method. It has higher efficiency of fault identification compared with the BP neural network and SVM model and a new way for the gear fault diagnosis is provided.关键词：IMF energy;Kurtosis;Least squares support vector machine;Gear;Fault diagnosis
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发布时间：2022-10-20 - 摘要：In view of bearing compound fault of the low signal-to-noise ratio of the gear transmission system,firstly,the fault signal is decomposed to the order of IMFs and residue. Taking the kurtosis as characteristic index,the kurtosis value of the IMF components is calculated and the IMF component which has the maximum kurtosis is demodulated by Hilbert envelope. The final result shows that the method can effectively improve the signal-to-noise ratio,the bearing fault characteristic frequency can be extracted from strong background noise of gear transmission system.关键词：Rolling bearing;Compound fault diagnosis;Ensemble empirical mode decomposition;Hilbert transform;Envelope
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发布时间：2022-10-20 - 摘要：The rigid-flexible coupled dynamics analysis model of crane reducer is built,the gear meshing force and bearing force are obtained by using variable step backward integration method,taking the bearing force as load boundary condition of the vibro-acoustic coupled model,the vibro-acoustic coupled analysis BEM model which include structural mesh,acoustic mesh and field mesh is set up in LMS Virtual Lab,the sound pressure at the surface and field of the reducer is got by using full method. The acoustic optimization model of crane reducer is established by setting the box thickness of reducer as design variable,the mass of the reducer as constraint condition,the field pressure as objective function,the optimal design variable is obtained by using normal boundary intersection optimization algorithm. The results show that the peak amplitude of surface sound pressure occur at center frequency of 500 Hz before and after optimization,the sound pressure of the four field points of the reducer are reduced after optimization.关键词：Reducer;Bearing force;Coupled analysis;Noise reduction
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发布时间：2022-10-20 - 摘要：To improve the locus accuracy of linear motion mechanism with uncertainty factor,the analytical algorithm of locus reliability sensitivity analysis for linear motion mechanism is presented. First,by using the equidistant curve,the boundary of motion locus is constructed,taking account of the component size tolerance,the error analysis model of structure error and random error for the linear motion mechanism is proposed.The analytical equations for the statistical characteristic value of the motion error are derived by using the linearization method. And then the first order and second moment（ FOSM） method is applied to solve the locus reliability of linear motion mechanism,and the analytical model for locus reliability sensitivity analysis of linear motion mechanism is derived. At last,a numerical example of Hoeken mechanism is given.关键词：Locus reliability;Sensitivity analysis;Hoeken mechanism;Linear motion
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发布时间：2022-10-20 - 摘要：In order to monitor and diagnosis running status of rolling bearing in the rotating machinery,a new method of rolling bearing fault diagnosis based on sideband correlation algorithm and Hilbert envelope spectrum is put forward. Through analysis on the rolling bearing vibration model,the vibration signal can be regarded as the superposition of multiple modulation signal,the best frequency range can be found basing on the basis of the spectrum by using the sideband modulation algorithm. Then,the band-pass filtering is carried out,the time-domain signal in this frequency range is got. Finally,the Hilbert envelope and the frequency spectrum analysis are carried out. Eventually,the size of the modulation frequency is got. The analysis and verification is carried out by using the vibration signal of rolling bearing experiment,finding out the modulation frequency of vibration signals under the condition of outer ring,inner ring,rolling body defect,the fault feature can be extracted effectively. The results show that the method can accurately identify and diagnose the fault location and fault type of rolling bearings.关键词：Rolling bearings;Modulating signal;Sideband correlation algorithm;Hilbert envelope spectrum;Fault feature
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发布时间：2022-10-20 - 摘要：The automobile transmission gear is the power carrier of a transmission system,the vibration characteristic of the transmission is largely determined by the dynamics characteristic. The time-varying contact line method is used to study the theoretical time-varying meshing stiffness theory solution. Combining with the internal incentives,such as the tooth pitch error,the shaft coupling nonlinear dynamics model of helical gear pair bending and twisting is established. The Runge-kutta method is used for numerical solution,the time-domain response curves and the frequency spectrum diagrams of the vibration response of a helical gear pair are obtained. The results show that,the smaller the time-varying mesh stiffness,the degree of gear vibration increases more rapidly. After joining the tooth pitch error,the vibration acceleration time-domain characteristics with axial vibration change is most obvious,and the smaller the tooth pitch error,the slower increase in the intensity of the vibration.
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发布时间：2022-10-20 - 摘要：In order to improve the reliability and rationality of a automobile transmission shaft design,the free modal,torsional stiffness,static strength and fatigue strength of a transmission shaft are analyzed based on the finite element method. The result shows that the first-order natural frequency is 15% higher than the excitation frequency,so the resonance will be effectively avoided. The torsional rigidity is 27 685. 5 N·m / rad,it meets the stiffness requirement. The maximum stress is located at the shaft tube,its value is 185. 2 MPa,the safety factor is 1. 32,it meets the strength requirements. The minimum life is 8. 165 × 107,it meets the fatigue life requirements.关键词：Transmission shaft;Modal;Stiffness;Strength;Fatigue
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发布时间：2022-10-20 - 摘要：To improve the static and dynamic characteristics of a high speed gearbox,the main object method of multi-objective optimization is applied in optimization analysis of structures in the high speed gearbox based on parametric design. The simulation results based on ANSYS Workbench prove that,by using multi-objective optimization,the high speed gearbox mass can be reduced,at the same time,the static characteristics,dynamic characteristics and the design efficiency of gearbox are significantly improved,the higher requirements in performance of high speed gearbox is satisfied,and a theoretical guide and reference for the optimization design and improvement of other critical parts of gearbox is provided.关键词：Parametric design;Multi-objective optimization;Simulation;Static and dynamic characteristic
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发布时间：2022-10-20 - 摘要：A comprehensive parameter measuring machine for precise RV reducer is developed,which can measure the parameters of transmission error,backlash,stiffness and friction moment and so on. This machine mainly consists of mechanical structure design,measuring & control system and measuring software,which can acquire the parameters of RV reducer rapidly and accurately by a simply one-time clamping. The mechanical structure includes base,input & output components and mounting support. By using the FEA software Hypermesh 12. 0,the output shaft strength is analyzed,it is meeting the strength condition under the condition of output maximum torque of 2 000 N·m when measuring the backlash.关键词：RV reducer;Transmission error;Backlash;Measuring machine;FEA
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发布时间：2022-10-20 - 摘要：In view of the problem of poor processing symmetry degree of high precision herringbone gear,an online type multi-degree of freedom gear phase detection device is designed,and the basic principle of symmetry error detection with the device is proposed. On the basis of that,the numerical control（ NC） programs for automatic checking the symmetry error is developed. Subsequently,the herringbone gear processing is realized with the application of the NC system to compensate the phase error. The herringbone gear processing experiments indicate that the online type multi-degree of freedom gear phase detection device is reasonable and reliable,and the symmetry error compensation based high precision herringbone gear processing method can steadily keep the symmetry degree within 0. 02 mm. Thus,the rationality and accuracy of the method is verified,and a new approach for high precision herringbone gear processing is provided.
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发布时间：2022-10-20 - 摘要：The variable-ratio wind turbine gearbox turns the variable input speed into constant output speed,which is a key component for the wind turbine front-end speed control. On the basis of the transmission principle of NGW differential gear train system,several types of variable-ratio transmission mechanisms of wind turbine gearbox are studied. The corresponding expressions and boundary conditions for gear design are derived for each mechanism, and the derived expressions are verified through professional software Romax WIND. At last,the actual example is enumerated,which is helpful for the design of this type of gearbox.关键词：Variable-ratio;Wind turbine gearbox;Differential;Power split
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发布时间：2022-10-20 - 摘要：The static torsion test,no-load running and dynamic test of the snake spring coupling are designed. And the test results show that the maximum torque of the research and development snake spring coupling can reach to 160 000 N·m,the torque and the relative angle of the two halves coupling are non-linear relationship,the strength can meet the requirements of design,it is put into use on the test equipment.关键词：Snake spring coupling;Static torsion test;No-load running test;Dynamic test
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发布时间：2022-10-20 - 摘要：In order to improve the precision of CNC machining ZC3 worm gear,a side milling method for machining worm gear is proposed. Firstly,the mathematical model for milling ZC3 worm gear is established based on the principle of gear meshing. Secondly,the worm gear tooth surface points are solved by MATLAB.By using the least square fitting method,the relationship between worm gear surface curvature and cross-sectional data from the worm gear axially is obtained. Then,the NC tool paths are generated by solving the non-uniform division method for tooth surface. Finally,the simulation of the generated machining program is carried out by using the VERICUT,the correctness of the proposed method is verified by comparing with the original calculation tooth surface data. The experiment shows that the proposed method can improve the milling universality as well as the efficiency compared with the conventional method for worm gear CNC machining.关键词：ZC3 worm gear;Side milling;Meshing theory;Tool path;Simulation processing
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发布时间：2022-10-20 - 摘要：Aiming at the problem of poor quality of the special screw rod surface,a combined machining method of milling and form grinding based on non-instantaneous pole envelop method is proposed. Firstly,the kinematic relationship between the disk milling cutter and special screw rod is established on the basis of non-instantaneous pole envelop method. Then the cutter location points are calculated for milling the special screw rod. Secondly,according to the mesh principle of form grinding and the space meshing relationship between the forming grinding wheel and special screw rod,the contact line between the form grinding wheel and special screw rod is solved,the calculation method of the form grinding wheel profile is derived. Lastly,through the simulation manufacturing,the correctness of the proposed method for calculating the cutter location points and grinding wheel profile based on non-instantaneous pole envelope method is verified.关键词：Special screw rod;Non-instantaneous pole envelope method;Form grinding;Simulation manufacturing
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发布时间：2022-10-20 - 摘要：The heat quantity generated by the working condition characteristic of high speed gearbox will lead to high temperature,and the high temperature especially local high temperature will make the lubricating condition badly,the contact and anti-scuffing strength of gear lower and the lubricating oil accelerated aging.Firstly,combining with the existing achievements at home and abroad,the mechanism of heat generating and transferring of the system and the determination of boundary condition are introduced. Then,the thermal network method,finite element simulation and test which widely applied at present are briefly introduced.关键词：High speed gearbox;Thermal mechanism analysis;Method overview
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发布时间：2022-10-20
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