最新刊期
期 2 ， 2017
- 摘要：In view of the torsional vibration of an electric vehicle（EV） driveline,based on the blendingμ integrated robust control theory,the control method of driveline is studied.Firstly,the driveline uncertainty model of a central-driven pure EV is established,considering the high-order unmodeled uncertainty of permanent magnet synchronous motor and the parameter perturbation.Then,μ-method is adopted to design the driveline robust controller.Finally,in order to verify the validity of the designed controller,the simulation and calculation are conducted by using Matlab / Simulink.Results show that the control strategy can enhance the robust performance and robust stability of the system,and reduce the possibility of system instability effectively.关键词：EV;Driveline;Torsion vibration;Robust control
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发布时间：2022-10-20 - 摘要：To further improve the fuel economy and online real-time optimization ability of energy management strategy for Hybrid Electric Vehicle（HEV）,the grey forecasting GM（1,1） model is established to forecast real-time vehicle speed,and then combined with Equivalent Consumption Minimization Strategy（ECMS） to be proposed HEV ECMS energy management strategy with grey forecasting method.Furthermore,the entire HEV simulation model is built,and the three different WVUCITY,WVUSUB and WVUINTER cycle is selected to simulate and analyze the effect of energy management.The simulation results show that,firstly,the precision of grey forecasting for speed is reliable.Secondly,the SOC will be more stable and battery has longer life by integrating grey forecasting and ECMS.Finally,the fuel economy is increased by 7.4%,7.5%,6.3%respectively through the proposed strategy,when compared with the non-forecasting method under the above three cycle.关键词：HEV;Grey forecasting;ECMS;Energy management strategy;Simulation
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发布时间：2022-10-20 - 摘要：To avoid the circularly shift range on multi-range hydro-mechanical continuously variable transmission（HMCVT）,taking the multi-range hydro-mechanical CVT of the wheel tractor of YTO-400 as example,the transmission characteristic of multi-range hydro-mechanical CVT is analyzed.The causes of the circularly shift range are researched,and eliminating mechanism is presented.The effectiveness of principle of averting the circularly shift range is simulated by using the theory of Finite State Machine,which employs the actual and theoretical displacement ratio,output speeds of multi-range hydro-mechanical CVT as the control parameter.The research results indicate that,the volumetric efficiency of the pump-motor system is the important reason for the factor of efficiency difference of the circularly shift range.By controlling the increase of the theory displacement ratio of the multi-range hydro-mechanical CVT,the actual displacement ratio is maintained at the same time,which effectively avoids the cycle change of the multi-range hydro-mechanical CVT.A theoretical foundation for the development of multi-range hydro-mechanical CVT control system is provided.关键词：Multi-range hydro-mechanical CVT;Circularly shift range;Efficiency difference;Volumetric efficiency
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发布时间：2022-10-20 - 摘要：The crack propagation characteristic property of the high-speed train gears is researched,the location of crack initiation is determined by a statics analysis and building gear pair model in the ABAQUS software.A finite element model of helical gear pair with crack at tooth root is established by ABAQUS software,then the stress intensity factor of the different nodes of crack tip is calculated based on the theory of linear elastic fracture mechanics.Then,the way and the growth trajectory of the crack is studied,the propagation life of the crack at tooth root are obtained by calculation.Based on the obtained result,the influence of load magnitude and other factors on the crack propagation life is discussed.The study indicate that the crack expands slowly at first and then faster and faster,the influence of load magnitude on the crack propagation life is obvious.关键词：Helical gear;Crack propagation;Life prediction;Finite element method
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发布时间：2022-10-20 - 摘要：Under the double pressures of energy crisis and environmental problems,the governments and the automobile enterprises have paid much attention to the pure electric vehicle which has advantages of zero emission,low noise and wide range of energy sources.Electric car is not very different from conventional cars,whether in the main structure or in the appearance.The main change is made in terms of drivetrain.Taking the pure electric city car as our research target,the power transmission system parameter is analyzed and designed,according to the vehicle parameters,power and economy requirements,the vehicle power system parameter is matched.The matched parameters of power system preliminarily is optimized from improving the transmission efficiency,taking the shortest time of acceleration and working conditions driving range maximum as optimization goal.The fitness function of transmission speed ratio is constituted of objective function and constraints condition by using a penalty function.The optimization is carried out by genetic algorithm,the optimal parameters of power system are obtained.关键词：Pure electric city vehicle;Powertrain;Parameter matching;Optimization
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发布时间：2022-10-20 - 摘要：In the process of innovation design,the contradiction network are often constructed as more than one contradiction which interact each other emerge from analyzing step of initial problem situation.It is the key problem for innovation design that how to select important contradiction,root cause contradiction and core contradiction correctly from contradiction network.As the result of analyzing on contradiction interaction pattern and strategy of contradiction network decomposing,oriented graph is used to expressed the interaction between contradictions in the network of contradiction,and the equation to get the cause degree of contradiction to others is built,then the selecting method of important contradiction,root cause contradictions and core contradictions based on DEMATEL is proposed,which involves the calculation of the important weight,causes degree and centers degree of a contradiction.Finally,a case study of reversing winch is used to verify that the proposal method is correct.关键词：Innovation design;TRIZ;Contradictions network;DEMATEL
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发布时间：2022-10-20 - 摘要：On the basis of the M-B fractal model,and combining with distribution formula of two cylinders contact area,a calculation model of tangential contact stiffness for gear joint surface is set up by using anisotropic fractal geometric theory.The influence of the main parameters in the model on the gear fractal contact model is obtained through emulation of MATLAB.The results indicate that the joint surface tangential contact stiffness increases with increasing material property or gear teeth,but decreases with increasing fractal roughness or ratio of total tangential load to total normal load.When fractal dimension is smaller（D < 1.7）,the gear joint surface tangential contact stiffness increases as fractal dimension increases.However,when fractal dimension becomes larger（D≥1.7）,the gear joint surface tangential contact stiffness decreases as fractal dimension increases.关键词：Gear;Fractal geometric theory;Tangential contact stiffness;Anisotropy
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发布时间：2022-10-20 - 摘要：By adopting a genetic algorithm for optimization of neural network,the gravity compensation for robot arm is researched.Firstly,through the basic knowledge of mechanics and D-H parameter to set up robot kinematics model,the theoretical computation formula of the gravity item of each joint torque in robot arm is got.Secondly,in the Solid Works simulation software,the simulation value of the gravity item in some certain pose got,thus the correctness of the theoretical computation formula is verified.Finally,the predicted value of the gravity item by genetic algorithm for optimization of neural network is obtained.Experimental results show that the predicted value of gravity items of robot arm learnt with this method is basically conforming with the theoretical value.Consequently,the work load of calculation for the gravity items of robot arm is effectively reduced.Furthermore,this method provide a possible way for the real-time control.关键词：Robot arm;D-H parameter;Gravity compensation;Neural network;Genetic algorithm
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发布时间：2022-10-20 - 摘要：To study the sampling and compilation method of load spectrum of passenger car transmission,taking a certain type of front-engine,front-wheel-drive passenger car transmission as an example,according to different road conditions,the road random load of this passenger car transmission is collected.According to the characteristics of the load,the amplitude cycle counting method is employed to complete the statistical treatment for various time dependent loads tested in the road test.The design load spectrum of the passenger car transmission is compiled.The sampling and compilation method of load spectrum of the passenger car transmission is established.The method can provide accurate design input conditions for passenger car transmission,and provide a reference for accurate fatigue life prediction and fatigue test.关键词：Passenger car transmission;Load spectrum;Sampling;Compilation;Extrapolation
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发布时间：2022-10-20 - 摘要：In the light of the defect and deficiency of the lever method in the analysis of the transmission of multi planetary gear transmission,it is expanded and improved.By using the new extended lever method,the transmission of each shift of the Mercedes Benz 722.9 Automatic transmission is analyzed.And the correctness of the extended lever method and the analysis are verified.关键词：Expand lever method;Automatic transmission;Shifting process
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发布时间：2022-10-20 - 摘要：The vibration and noise generation mechanism of the gear rattle in manual transmission is analyzed.According to the measurement of the size and the test of the NVH,the gear rattle in manual transmission is caused by the severe torque fluctuation of input shaft.The working principle of the dual mass flywheel（DMF） damping the gear rattle noise in manual transmission is analyzed.Through the experiment,the DMF can effectively damp the torque fluctuation of input shaft is verified,the gear rattle of the passenger car manual transmission can be controlled in a reasonable range as well.关键词：Manual transmission;Gear rattle;Torsional vibration;DMF
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发布时间：2022-10-20 - 摘要：The pitch deviation error of tool retracting position is a critical problem during the machining process of gears with numerical control（NC） shaping machine.After analyzing the influence factors of gear machining accuracy,generating motion out-of-sync is identified as the primary cause of the pitch deviation error in the case of well controlling of geometric accuracy,motion error and positioning precision.In order to reduce the influence of gear installation error and measurement error on gear pitch deviation measurement precision,an online gear precision detection device is designed.According to the influence law of servo gain parameter on the control shaft of servo motor,several orthogonal gear shaping tests are carried out by changing the servo gain parameter.The test results prove that the generating motion out-of-sync of tool retracting position is the primary cause of the pitch deviation error of tool retracting position.Simultaneously,the influence law of servo gain parameter on the pitch deviation error of tool retracting position is analyzed and the corresponding parameter adjustment strategies are proposed.The study provides a new approach to solve the pitch deviation error problem of tool retracting position with NC shaping machine.关键词：Generating motion out-of-sync;Pitch deviation error;Influence law;Adjustment strategy
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发布时间：2022-10-20 - 摘要：The hyperboloidal-type normal circular-arc gear is a new circular-arc gear used in crossed axis transmission.In order to study its characteristics of vibration,the FEM model is created based on ANSYS.The natural frequency and modes of vibration of pinion and gear are obtained respectively through the modal analysis and the critical speed of rotation is computed.Further,the natural frequencies of pinion and gear under the condition of different number of teeth,modulus and the transmission ratio are calculated.The influence of main geometric parameters on natural frequencies is analyzed and summarized,which provide basic for the optimal design and dynamics research of hyperboloidal-type normal circular-arc gear.关键词：Hyperboloidal-type normal circular-arc gear;FEM;Modal analysis;Gear geometric parameter
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发布时间：2022-10-20 - 摘要：The Working space is an important performance and design index in evaluating parallel manipulator.The 3-PRRRR parallel manipulator branched chain is simplified reasonably,by using the D-H method,the 3-PRRRR parallel manipulator inverse kinematic analysis is carried out,the equation of inverse kinematic analysis is obtained.By using the MATLAB,the numerical simulation of its inverse kinematic analysis is carried out.According to the characteristic of the 3-PRRRR parallel manipulator,by choosing the method of scanning,the equation of inverse kinematic analysis is carried out.The simulation of the workspace of the 3-PRRRR parallel manipulator is carried out by using MATLAB,a certain theoretical basis for the future study is provided.关键词：Parallel Manipulator;Kinematic analysis;Workspace;MATLAB simulation
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发布时间：2022-10-20 - 摘要：The solid assembly model is set up in the Pro / E,and then imported into ADAMS.Based on the orthogonal experimental design with the visual and variance analysis method,the error of the center circle radius of the pin gear,moving distance and the isometric modification of the cycloid gear,the influence of the error of eccentricity and the radius of pin gear on the transmission accuracy are compared and analyzed,and the calculation formula for calculating the transmission error is deduced according to the influence factors.The results show that the error of the center circle radius of the pin gear has the greatest influence on the transmission error of the RV reducer,and the influence of the eccentricity error of the RV reducer is the least.It comparison with the simulation results shows that the calculation formula of transmission error is correct and reliable.关键词：RV reducer;Driving error;Orthogonal simulation;Adams
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发布时间：2022-10-20 - 摘要：Due to the current situation of Chinese high-speed motor train unit（EMU） gearbox monopolized by foreign for a long time,and facing the gearbox body cracking problems frequently,the aluminum alloy box body of high-speed EMU is redesigned.By using the three-dimensional modeling software Solid Works,the box body model is created,and the load calculation of the designed box body under two conditions of short circuit and startup is carried out separately.By using the finite element analysis software Workbench,the strength is analyzed,then the simulation test results verify the designed box body won’t appear plastic deformation and crack in both working conditions.According to the analysis results evaluated by TJ / JW064-2015 in startup conditions,to testify that the designed housing meet the requirement of train operation.The research has important reference value to the independent research and development of the high speed Emu gearbox.关键词：Motor train unit;Aluminium alloy body;Workbench;Light weight
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发布时间：2022-10-20 - 摘要：The vibration acceleration signals of two gearboxes under the load condition of 1 600 3 000 N·m are collected.The changes of time domain characteristic parameters and the sensitivity of gear meshing frequency and harmonics amplitude to the load change are analyzed.The results show that the gear meshing frequency amplitude is approximately linear with the load level.Both of the harmonic frequency 3fmof gearbox A,the harmonic frequency 3fm,4fmand high order harmonic frequency 10fm 13 fmof gearbox B are sensitive to the load level.The results have some significance for the further study of vibration characteristic on heavy duty gear transmission.关键词：Heavy duty gear;Vibration;Load;Time domain analysis;Frequency spectrum analysis
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发布时间：2022-10-20 - 摘要：The studies on non-circular gear cutting and using errors are generally based on theory of cylindrical gear errors,and the similarities and differences between cylindrical gear and non-circular gear are combined to study the change rule of non-circular gear contacting line and obtained corresponding conclusions.From a different perspective,by starting from the non-circular gear engagement principle,on the basis of analyzing the concrete geometric error conditions,the new type tooth profile algorithm routine is reasonably modified,and the non-circular gear tooth profile error contrast figure is obtained.Furthermore,the theoretical verification is carried out by incorporating analytical method and contacting line incremental method,a reasonable classification method is proposed based on the characterization of the error characteristic code in the general case and the error genetic map used to guide practical production is summed up which possess enormous significance to non-circular gear machining.关键词：Non-circular gear;Tool setting error;Analogue simulation;Error genetic map
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发布时间：2022-10-20 - 摘要：In order to obtain the load time history data of the shaft parts of loader drive system under the actual load,based on the load transfer principle and the design theory of the sensor,the load time history of shaft parts of the multi parameter test method is researched.Aiming at the key and difficult points of the load spectrum testing of the loader drive system,the dynamic telemetry device is used to solve the problem of parameter measurement in small space.The load signal acquisition system of loader shaft parts is established.And the system consisted of half shaft,drive shaft torque and speed parameters acquisition,engine speed parameters and the acquisition of gear parameters.The load time history data of the shaft parts are obtained by selecting the 50 type loader as the test sample.The test results show that the load test method is accurate and feasible,and the test method has very good generality and could be used for testing the load data of shaft parts of automobile,agricultural machinery and so on.
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发布时间：2022-10-20 - 摘要：The dynamic characteristic of the belt conveyor in the start-up operating condition is analyzed,the dynamic simulation analysis of the take-up device of the belt conveyor started by the styles of the combined cycloid,Nordell and equal acceleration and the optimization simulation analysis of the pulling force are carried out,the oversize and the undersize of local stress in the belt is prevented,so that the security and reliability of the belt conveyor can be ensured.关键词：Belt conveyor;Take-up device;Start-up process;Dynamic characteristic
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发布时间：2022-10-20 - 摘要：The shape memory alloy（SMA） actuator has many excellent properties,such as simple structure,easy to control,high power weight ratio,which makes it widely been studied in the dexterous hand as actuator.But the driving displacement is small in practical application,and need to place the drive into the arms to increase drive displacement.The module of under actuated finger structure is designed.The SMA wire worked as actuator.A novel pulley which could amplify the output displacement of actuator is designed.The permanent magnet device provided pre-stretch and restore function,which implemented the drive and transmission of one-piece lightweight design.The transmission structure of the humanoid dexterous hand is analyzed.Finally,the model of finger is made by 3D printer and assemble the single finger,implements the crawl of daily supplies.关键词：SMA actuator;Pre-stretch;Permanent magnets;Displacement amplification;Under actuated
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发布时间：2022-10-20 - 摘要：A new type of 3-PPR spherical parallel mechanism is proposed.Due to the mobile pair special trajectory in each branch chain,the mobile pair can be equivalent conversion for revolute pair.Based on screw theory,each branched chain motion screw system is given.The mobility of this mechanism is analyzed firstly with the amendment G-K formula,The numbers of degrees of freedom is obtained.Secondly,by using the solution method of inverse spiral system and matrix theory knowledge,under the premise of Jacobian matrix of the 3-PPR spherical parallel mechanism is solved,the rank of matrix is analyzed,the singular configuration conditions and the type of singular configuration of the mechanism are obtained.In the end,according to the forward kinematics solution and interference condition,the Matlab software is used to draw up the stable working space.Research shows that a 3-PPR parallel spherical mechanism singularity is less,and easy to avoid,has good application prospect.关键词：Parallel spherical mechanism;Screw theory;Jacobian matrix;Singularity;Positive position solution;Working space
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发布时间：2022-10-20 - 摘要：Combined dynamic shift schedule for the hydraulic automatic transmission is designed.The fuzzy control with the vehicle speed,throttle opening and acceleration as the control parameters are used to modify the shift schedule based on the dynamic characteristics of engine.The ramp conditions are amended by the speed attenuated dynamic shift schedule.The simulation results show that dynamic revised shift schedule has a better power performance and is more in line with driver intention.The amended shift schedules under ramp conditions can solve the problems of shift cycle under uphill condition and rising to higher shift under downhill condition,so that frequent shifting is avoided.关键词：Vehicle engineering;Shift schedule;Dynamic modification;Automatic transmission;Shift cycle
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发布时间：2022-10-20 - 摘要：With respect to the design calculation of the interference fit construction of the output shaft of cooling water pumps used in a nuclear power plant,the design calculation and checking are carried out by using standard formulas and numerical methods specified in the National Standards for limit and interference fit.The contact pressures at the maximum and minimum interference are obtained respectively,and the assessment of the reliability of transmitted torque and material is conducted,then the minimum temperature required for interference assembly is calculated,the protection for the safe and reliable operation of pump is provided.关键词：Gearbox;Output-shaft;Interference fit;Analysis
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发布时间：2022-10-20 - 摘要：As a model adopted in robot kinematics,MDH model is hardly mentioned in domestic literature.The MDH model about rotating joint is introduced in detail,taking a new type of hybrid palletizing robot as example.The kinematics equations of the robot are deduced by combining solving solely through reference coordinate system with homogeneous transformation solution.The 5-3-5 method is used in trajectory planning,and the program is written by using MATLAB,corresponding kinematics simulation is completed in LMS Virtual.lab Motion.The correctness of theoretical derivation is verified through comparing the results of simulation with calculation.It provides a theoretical basis for establishing robot kinematics precision model and make up the lack of MDH model in domestic literature.关键词：Hybrid robot;MDH model;Kinematics analysis;Trajectory planning;LMS Virtual.lab simulation
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发布时间：2022-10-20 - 摘要：By using the function of eigen buckling in ANSYS,the torsional buckling problem of flexspline in a harmonic driver is analyzed. Through changing the structure parameter of two kinds of flexspline,the corresponding critical instability torque under each structure parameter is investigated. The research results show that the mode shapes of torsional buckling are close to that of the actual instable failure,and computation result is good agreement with engineering problem. So the torsional buckling check will be valuable in the flexspline structure of harmonic reducer.关键词：Harmonic drive;Flexspline;ANSYS;Eigen buckling analyzing
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发布时间：2022-10-20 - 摘要：The conveyor chain model which include constrained and free pin is established.Through analyzing each position of pin in static and the movement velocity and displacement of pin in one period are calculated according to its coordinate.The mathematical model of each pin in the state of motion is established and the motion trajectory of free pin should include two parts because of the polygonal action of the chain is proposed.Aiming at the problem of the nonlinear equations in the mathematical model of chain is hard to calculate,a kind of solution method based on fundamental theorem of calculus is presented.Finally,motion trajectory of top and bottom edge free pin is obtained by using the MATLAB point depiction method.A computation method is provided for the analysis of trajectory constrained conveyor chain and the design of constrained trajectory.关键词：Constrained trajectory conveyor chain;Free pin;Trajectory;Point depiction method
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发布时间：2022-10-20 - 摘要：Aiming at the problem of multi-objective reliability optimization for the reducer of road-rail vehicle,firstly,it must be ensured that the electric wheel planetary gear reducer is in good working order and loading conditions meet the requirements of transmission.By applying the reliability theory and optimization design technology,the reducer weight reduction,materials saving,low cost can be realized safety and reliability is improved.The MATLAB optimization toolbox is used to solve the problem of the optimization of reducer.Taking the volume and contact ratio as multi-objective optimization function,then the multi-objective optimization problem is transformed into single-objective problem to solve by the linear weighted method.The mathematical model is established by using the safety factor method and other constraints.By using Fmincon function,the optimizing calculation and analysis are carried out,the optimal solution is got,which makes the optimization design parameters more reasonable than the original design parameters.Consequently,the results show that the working performance of the electric wheel of the road-rail vehicle is improved.
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发布时间：2022-10-20 - 摘要：In order to satisfy the specific engineering application requirements of swinging guide bar mechanism,the swing guide bar mechanism can be driven by motor output one-way variable motion under the conditions of each bar length is determined,the output motion characteristic of the swing guide bar mechanism is optimized and the comprehensive performance is improved.Considering the non-circular gear transmission characteristic,by using uniform motor driven non-circular gear for one-way variable motion function,which can also achieve the same movement request.The movement diversity and applicationof the mechanism is verified,at the same time,a reliable research method of the series assembly mechanism,reverse design of non-circular gear and optimization design is provided.关键词：Noncircular gear;Swing guide bar mechanism;Series assembly mechanism;Optimal design
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发布时间：2022-10-20 - 摘要：To study the motion characteristics of S-typed trajectory carbon-free car,and thus to optimize the design and adjustment.Through using the steering link mechanism to achieve carbon-free car S-type trajectory motion characteristic of the steering mechanism,the mathematical model of the relationship between the crank angle and the angle of the front wheels is built and its steering mechanism characteristics simulation is carried out by using MATLAB,the relation diagram of crank angle and the front corner of the is obtained.The mathematical model of the car trajectory is established,the parameters influence on the motion trajectory and their influence law are obtained,the relevant amount of the trajectory amplitude value is found and trajectory motion simulation of the car is carried out by using MATLAB.Eventually,the optimal cosine trajectory with the pile of 0.9 m,the amplitude of 0.095 m is got,the crank length is 21 mm at this time,a theoretical guidance for S-type carbon-free car design and adjustment is provided.关键词：Carbon-free car;Motion characteristic;Trajectory optimization;Matlab
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发布时间：2022-10-20 - 摘要：The meshing efficiency calculation method of spur gear is studied,from the power consumption launched,the meshing efficiency calculation function of straight tooth cylindrical gear is deduced,the variation average friction coefficient instead of assuming constant friction factor is introduced,the more accurate meshing efficiency calculation formula of involute gear is obtained.Combined with the Matlab software simulation analysis,the relationship between the gear meshing efficiency and the gear basic parameters is obtained,which can provide some methods to improve the efficiency of gear transmission.关键词：Spur gear;Meshing efficiency;Friction factor;Matlab
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发布时间：2022-10-20 - 摘要：The current experience-dominated structural design process separates the structural design from CAE analysis in the development of a new wind turbine gearbox,which leads to a quite long-term development cycle and the redundancy of structural materials.Consequently,a new structural design process is presented based on topological optimization theory and combined with CAE.Through a secondary development for Hyperworks with C# and TCL / TK language,a new process automatic system characterized by lightweight structure for the structural design of wind turbine gearboxes is developed.The operability of the system is testified by the instance of designing a planet carrier.The case indicates that the process automatic system can lead designers to finish the lightweight-oriented structural design for wind turbine gearbox parts,and the pre and post processing efficiency can increase by 90% than the current process,and the development cycle of new products of wind turbine gearbox is shorten enormously.关键词：Wind turbine gearbox;Structural design;Process automation;Secondary development
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发布时间：2022-10-20 - 摘要：The method of transmission error detection is applied to gear fault diagnosis,the transmission error signal of the gear system is obtained by measuring pulse width time of the gearbox shaft angular encoder output two square wave pulse.Secondly,the transmission error signal is decomposed into a finite number of intrinsic mode components（IMF） by the method of empirical mode decomposition,and then the IMF component containing the most dominant fault information are filtrated to merged into a new signal.Finally,the order analysis and spectrum analysis on the new signal is carried out,the fault characteristics are obtained and gear fault diagnosis is realized.The designed two channel data acquisition card is applied to build up the gear fault analysis test system based on the method of transmission error detection.The experiment results show that the gear fault analysis test system can be effectively diagnose the gear fault.关键词：Transmission error;Empirical mode decomposition;Order analysis;Fault diagnosis
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发布时间：2022-10-20 - 摘要：To increase the stroke of precision positioning system,a large stroke series flexure mechanism based on elliptical flexure hinge is presented.The method of pseudo-rigid-body model is applied to analyze the motion process of the series flexure mechanism,and the theoretical model of stiffness and maximum stress is established.Taking the ultrasonic linear motor as the driving element,a unidirectional 2.5 mm stroke as design objectives,the structural parameters of the series flexure mechanism are achieved,the result error between finite element analysis and theoretical calculation is less than 5%,which proved the correctness of the design.A positioning system which having millimeter stroke is built,and a continuous stepping experiment is carried out,the experimental results proved that the system which could realize the precise positioning and has large stroke.关键词：Series flexure mechanism;Precision positioning;Stiffness;Maximum stress;Finite element
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发布时间：2022-10-20 - 摘要：Aiming at the problem of extraction difficulty of early non-stationary weak fault signal feature,low resolution of characteristic parameter,early fault diagnosis difficult exist in the rolling bearing fault diagnosis,a fault diagnosis method based on least squares mapping（LSM） fault characteristic parameter optimization and support vector machine（SVM） is proposed.Firstly,the non-dimensional symptom parameters（NSPs） in the time domain can reflect the features of the vibration signals measured in each state are calculated.Then,the high sensitivity symptom parameters are built by optimizing the calculated non-dimensional symptom parameters（NSPs） in the time domain with the LSM theory.Finally,the symptom parameters selecting by sensitivity identification factor are input to the SVM for the fault diagnosis,the fault type of bearing is identified through the sequential inference diagnosis.The practical examples of fault diagnosis for a motor bearing are shown to verify that the method is effective.关键词：Fault diagnosis;Least squares mapping;Support vector machine;Non-dimensional symptom parameter
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发布时间：2022-10-20 - 摘要：A kind of wheel brake of a heavy vehicle is studied by using virtual prototype technology.At first,the main parameters of the wheel brake,such as actuation force,brake torque are calculated.The virtual prototype model of wheel brake is simulated and analyzed with the ADAMS software,the obtained total braking torque are consistent with the results from the theory calculation.Through simulation analysis,it can be found each friction plate has its own corresponding braking torque.The surface stress of each friction plate is analyzed by using the finite element software ANSYS,the simulation results is proved by using ADAMS software on the braking torque of the friction plate.Through the simulation analysis,it is also found the influence relationship among friction coefficient,vibration amplitude,vibration spectrum.A new idea to the research method based on virtual prototype for wheel brake optimization is provided.关键词：Wheel brake;Virtual prototype technology;Adams;ANSYS
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发布时间：2022-10-20 - 摘要：Aiming at the online wear condition monitoring of a mining reducer for engineering applications,the relationship between wear debris features and wear status is studied.Firstly,ferrograph images are firstly captured by using an online wear debris image acquisition system.Secondly,the wear particle features are extracted by utilizing digital image processing technology,where the Otsu’s automatic thresholding method is employed to separate wear particles from the image background,and the debris features of relative concentration and the maximum width are extracted using a pixel scanning method.Finally,the wear status of a mining reducer is analyzed based on the statistical features of online wear debris.Additionally,the experiments are carried out and the results demonstrate that the proposed method is effective to monitor a running machine.This study also provides a new approach for automatic monitoring and intelligent maintenance of mining reducer.关键词：Online monitoring;Wear debris analysis;Feature extraction;Image processing
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发布时间：2022-10-20 - 摘要：In view of the meshing impact of the gear pairs of the experimental prototype based on the new-type of the planetary reducer with few teeth difference,which is proposed by Xiao Nanping and received the patent for this invention,the three-dimensional model of this reducer established by Solid Works is introduced into the ADAMS to build the model of the virtual prototyping of the reducer.The correctness of this virtual prototype is proved by the simulation of the angular velocity of the input and output shaft and the changing law of the meshing force of the gear pairs with the help of the software ADAMS.And the inertia force caused by the eccentricity of the planet gear has little influence on the meshing force of the gear pairs by comparing the simulation results with the theoretical calculation.And this result can provide the data support for calculating the strength of the gear pairs precisely and analyzing the contact stress of the pairs.
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发布时间：2022-10-20 - 摘要：A method for measuring the involute spline over pin distance without over pin is provided.By using the PC-DMIS software,the actual tooth profile of involute spline is measured by digital model.The tooth profile coordinate is imported into Solid Works software,the fitting and measuring of over pin distance is carried out by the tangency function of the Solid Works software,and the result is compared to the instance.This method has the advantage of small uncertainty of measurement,easy to realize parameterized automatic measurement,etc.关键词：Involute spline;Digital model;Over pin distance;SolidWorks;PC-DMIS
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发布时间：2022-10-20 - 摘要：The research and development of walking system of the composite vehicles is imminent and the conversion device of the walking system is the key part of composite vehicles.The four conversion devices in composite vehicles are introduced,the working principle and conversion technology are analyzed and studied in details.And then,the characteristic for every conversion devices in some composite vehicles are concluded and hope to provide reference for the research of composite vehicles in home and abroad.关键词：Composite vehicles;Walking system;Conversion device;Conversion technology
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发布时间：2022-10-20
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