最新刊期
期 3 ， 2018
- 摘要：The meshing backlash of cycloidal-pin wheel drive in RV reducer is the key factor that affects the transmission performance. At present,the formula method is adopted mainly to calculate the initial meshing backlash of cycloidal-pin wheel. But there are some differences between the theoretical result and the actual value because the formula method did not consider the change of node position in the process of drive. Taking the distance between the profiles in the direction of the common normal as the accurate meshing backlash is proposed. The traditional initial meshing backlash calculation method is analyzed and the tooth contact model of cycloidal-pin wheel is established,then the accurate meshing backlash at any angle is obtained. A theoretical basis for calculating and analyzing the exact meshing backlash of cycloidal-pin wheel drive in RV reducer is provided.关键词：RV reducer;Cycloidal-pin wheel;Common normal;Accurate meshing backlash
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发布时间：2022-10-20 - 摘要：The brachistochrone is a cycloid and is also a tautochrone. The evolute of the cycloid is still a cycloid. The study of the universal cycloidal gear found that,the tooth profile of the universal cycloid rack is at the high velocity region of the tautochrone. In the universal cycloidal gear,when the meshing line in the gear of all the teeth and gear of the rack are perfectly coincident with the same modulus,the extremely low controllable sliding rate of the performance can be deduced. The sliding ratio of universal cycloidal gear is 80% lower than the involute gear,it shows the superiority of the universal cycloidal gear.关键词：Universal cycloid gear;Brachistochrone curve;Tautochrone;Evolute;Meshing line;Sliding rate
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发布时间：2022-10-20 - 摘要：A 3-SPS/S parallel rehabilitation mechanism is proposed for the present situation of ankle rehabilitation institutions and the constitution of mechanism is introduced. The degree of freedom is calculated and the position inverse solution equation is established. Combined with numerical examples,the solution of the inverse equation is solved by MATLAB and the simulation results are verified by ADAMS. The simulation results show that the robot can meet the needs of ankle joint rehabilitation by changing the branching movement input.关键词：Rehabilitation;Kinesmatics;Ankle;Adams
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发布时间：2022-10-20 - 摘要：In order to research the meshing contact impact stress distribution rule of the circular arc tooth trace cylindrical gear,the cause of meshing contact impact is analyzed based on gear system contact dynamics and gear physical model. Then,the accurate 3 D model is set up based on the gear tooth surface equation,and the finite element analysis models of the meshing contact impact with different impact positions are established further. Finally,the simulation analysis of the meshing contact impact under the different impact speed,which occur at different positions is carried out,the distribution rule of the gear surface meshing contact impact stress are studied. Results show that,the dangerous area of the driven gear is close to the gear root of the loaded tooth surface,when the meshing contact impact takes place in the reference circle and gear top; the dangerous area is close to the gear root of no loaded tooth surface,when the meshing contact impact takes place in the gear root.关键词：Circular arc tooth trace cylindrical gear;Contact impact;Impact stress;Stress distribution
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发布时间：2022-10-20 - 摘要：The cylindrical roller enveloping end-face internal engagement worm gear with the worm-wheel rotational deflection is a novel transmission that can achieve multi-load and different corner angular outputs. Analysis of the effect of the worm gear deflection angle on potential root-cutting and rotation of performance is important for understanding the device. The analysis of root-cutting and performance of rotation is carried out by using boundary curve equation and rotational formula. The study indicates that the worm-wheel rotational deflection angle that is equal or larger than 44° has occurred undercutting,and the performance of rotation is degraded with the increase in wheel rotational angle; at the same time,performance of rotation is degraded with the increase in the curvature of the contact line on the cylindrical roller. The study provides a reference for the selection of the worm-wheel rotational deflection of this new driving.关键词：Worm-wheel rotational deflection;Internal engagement worm gear;Root-cutting;Performance of rotation;Contact line
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发布时间：2022-10-20 -
Analysis of the Characteristic of Meshing Impact Load for Constrained Conveyor Chain with Long Pitch
摘要：The conveyor chains bear a periodically impact loading due to the polygonal effect. The model of constrained trajectory of conveyor chains with long pitch is built toward this issue. The model is divided into two parts: chain wheel and top edge. The kinematics models of the two parts are established based on the Lagrange equation to calculate the generalized moment. In order to calculate the contact stress between the pins and other parts more precise,the models of chain wheel-pitch and pitch-pins are built by using the ABAQUS.The generalized moment is used to calculate the maximum contact stress and its position on pins. The consequence may provide some reference for the selection of material and the method of heat treatment.关键词：Constrained trajectory;Chain;Impact load;Generalized moment;Contract stress- 3
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发布时间：2022-10-20 - 摘要：The hydro-mechanical transmission（ HMT） is obtained by connecting hydraulic transmission and mechanical transmission in parallel. It has the advantages of high torque of hydraulic transmission and high mechanical transmission efficiency. The dual hydro-mechanical transmission（ DHMT） is connected by two sets of double flow. The components of the DHMT system are modeled and the shifting control strategy of DHMT system is proposed based on the established dynamics model. The co-simulation model of DHMT is built based on AMEsim and Simulink. Finally,the simulation results are analyzed and the correctness of the shifting control strategy is verified.关键词：Dual hydro-mechanical transmission;Dynamics modeling;Shifting control strategy;Co-simulation
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发布时间：2022-10-20 - 摘要：Gear is an important part for mechanical transmission. In order to avoid the case of bending fatigue fracture during transmission,with the maximum bending stress of the tooth root as the objective function,and the tooth thickness greater than 0. 25 m and the coincidence degree greater than 2 as the constraint,the tooth profile parameters are optimized. In the case of the center distance constant,the solution is optimized by using the loop in Matlab,and then the finite element model of the gears is founded by ANSYS APDL language.The bending stress analysis is carried out in the meshing state to verify the reliability of the optimization results,which has a guiding significance to reduce the bending stress.关键词：Gear;Coincidence degree;Bending stress;Fatigue fracture;Finite element
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发布时间：2022-10-20 - 摘要：For improvement of the transmission accuracy and static and dynamic characteristics of a transfer gearbox of a test-bed. By using the finite element software Abaqus,a numerical calculation model can be established to make static and dynamic characteristics analysis. Firstly,by making static analysis of typical working condition based on finite element,the condition of stress and deformation is achieved to check the static reliability of its structure. Then,the possibility of resonance under the normal working conditions is ascertained by using modal analysis. The purpose of this is to provide theoretical basis and guidance for the following structural optimization design. Research shows,the gearbox is reliable in structure and has a great space for optimization.The structural optimization can be used to improve the transmission accuracy and static and dynamic characteristics.关键词：Finite element;Static analysis;Modal analysis;Structural optimization
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发布时间：2022-10-20 - 摘要：To improve the performance of adjusting performance for wall-press oil and gas in-pipe robot,part of the in-pipe robot adjusting mechanism is parametric modeled and optimization designed through ADAMS. The integrated adjusting mechanism model is set up by Solid Works according to the optimized data and the structure characteristics of adjusting mechanism for in-pipe robot,then imports the model and makes simulation analysis in ADAMS. The optimized nut horizontal thrust is reduced 41. 5%,besides,the impact load which acts on adjusting mechanism of in-pipe robot is simulated,the influence of the horizontal thrust and changes in the situation of compression spring when the adjusting mechanism is in the process of adjusting or suffering impact load is separately obtained,the theoretical basis for the selection of suitable motor and the compression spring is provided.关键词：In-pipe robot;Adjusting mechanism;Adams;Optimization design;Simulation analysis
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发布时间：2022-10-20 - 摘要：In order to solve the problem that the drum length is too large and the hardness of the tooth surface is less than the requirement of noise,vibration and acceleration of the gear pair,the DEFORM-HT finite element software is used to simulate the spiral bevel gear. The effects of the four main parameters such as the temperature of the cooling medium,the inlet speed of the quenching tank,the temperature of the gear insulation and the carbon potential of the cooling and diffusion stage on the drum length and tooth surface hardness are studied. Secondly,the orthogonal experimental design and analysis method is used to optimize the index of gear drum length and tooth surface hardness. The optimum process parameters are obtained by numerical analysis of variance and variance. Finally,the results show that when the medium temperature is 100 ℃,the inlet speed is1. 5 m/s,the holding temperature is 835 ℃,the carbon potential is 1. 0%,the drum length is the smallest,the hardness of tooth surface satisfies the hardness requirement of the actual production.关键词：Spiral bevel gear;Dynamic thermal boundary;Carburizing quenching;Orthogonal experimental design
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发布时间：2022-10-20 - 摘要：In order to improve the adaptability and flexibility of the hexapod bionic robot to the working environment,based on the analysis of the physical form of bionic beetle and structural characteristics,taking the beetles as reference,a kind of six-foot symmetrical insect structure robot with good performance and simple structure is designed. The 3 D solid model is generated by using CATIA 3 D modeling software,which is imported into ADAMS to establish the dynamics model of virtual prototype. The gait of the hexapod robot walking on the flat ground and the gait of the fixed-point turning are analyzed. The curve of kinematics and dynamics characteristics are obtained,and the rationality of the structure and the feasibility of the motion are verified. It provides the theoretical basis for the numerical calculation of the robot and the development of the physical prototype,and also creates the conditions for the precise control of the hexapod bionic robot.关键词：Bionic beetle;Hexapod robot;Structural design;Gait trajectory;Kinematic simulation
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发布时间：2022-10-20 - 摘要：The Hydro-Mechanical Continuously Variable Transmission（ HMCVT） is a twin drive transmission,which divides the output power of the engine into mechanical power and hydraulic power through the shunting mechanism,and the power is converged by the confluence mechanism so as to realize the effect of continuously variable speed. Through consulting a large amount of documents and materials,a new transmission scheme is put forward according to the working principle of hydro mechanical stepless transmission. Based on the transmission scheme,the design and calculation of the technical parameters of the main key parts are carried out,then the final structural parameters of each component are determined,and the strength checking calculation is carried out. On this basis,the 3 D model of every part is built in Creo 2. 0,and then the virtual assembly drawing is completed. Finally,the finite element analysis of the main parts is carried out by using ANSYS. The results show that the design of this structure is reasonable.关键词：HMCVT;Transmission scheme;Transmission structure;3D Modeling;Force analysis
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发布时间：2022-10-20 - 摘要：In order to improve shift performance of synchronizer,the dynamic simulation model of synchronizer is established by using AMESim softwwere. The influence of three factors on shift performance of synchronizer,such as equivalent moment inertia of the input,friction coefficient of synchronous ring and the friction angle of synchronous ring are analyzed. The four evaluation indexes are proposed,which are synchronous impulse,shift work,secondary impact and shift time. The final performance evaluating indicator is established by the method of normalization. Finally,the optimal model is obtained by the method of gradual simulation,which greatly improves shift performance of transmission.关键词：Synchronizer;Shift performance;Evaluating indicator;Parameter optimization
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发布时间：2022-10-20 - 摘要：The Stewart-Gough platform is optimized by using the differential evolution algorithm. Firstly,the symmetric structure and unsymmetric structure of Stewart-Gough platform are introduced. Secondly,the objective function is defined by considering the effects of the limited of workspace,the singularity con? gurations existing inside the workspace and the high cost. Finally,the tool selected for optimization is the differential evolution algorithm,and it is used to optimize the structure of Stewart-Gough platform. The results of optimization suggests that the aim of maximize the payload and minimize the forces at each leg needed to counteract external forces applied to the mobile platform can achieved by appropriate select the Stewart-Gough platform structure and parameters. Compared with other algorithms,the differential evolution algorithm has better global search ability,thus select the differential evolution algorithm as optimization tools. The optimization and simulation process are achieved by using MATLAB.关键词：Differential evolution algorithm;Stewart-Gough platform;Optimization
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发布时间：2022-10-20 - 摘要：In order to calculate the bending stress of the gear accurately,a finite element analysis method of gear with load shaft is proposed based on the three-dimensional accurate modeling. The position of the single-tooth meshing point and the load angle are calculated. The load shaft is mounted contact with the gear.By comparing with the traditional calculation method of the tooth root stress,the correctness of the finite element analysis method of gear with load shaft is demonstrated. The results show that the thickness of the rim has no effect on the tooth root stress by calculating the spur gear with the finite element method,and the limitation of the finite element methods is put forward.关键词：Gear with load shaft;Finite element;Bending stress;Rim thickness
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发布时间：2022-10-20 - 摘要：The analysis and discussion of the calculation formulas in the ISO 21771: 2007（ Gears-Cylindrical involute gears and gear pairs-Concepts and geometry） are carried out,and the contrast and analysis of the formulas in DIN ISO 21771: 2014,ISO 21771: 2007 and DIN 21773: 2014 are carried out. Some suggestions are proposed for the improper parts of the formula,in order to provide reference for standard revision and users.关键词：ISO 21771: 2007;DIN 21773: 2014;Calculation formula;Wrong
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发布时间：2022-10-20 - 摘要：RV reducer is a mechanical system,will inevitably yield vibration in its operation process.Three measuring points are arranged on the RV reducer and the vibration signals generated in the work is investigated with the RV reducer test rig and vibration test system. The vibration signals of domestic SHPR-20 E RV reducer under different speed and load are collected and analyzed. Then,the vibration signals are analyzed in time domain and frequency domain. With the signal analysis,the vibration characteristics of the RV reducer can be mastered,which provides the test foundation for the research of RV reducer dynamics study,fault diagnosis and extraction,vibration and noise reduction in the future.关键词：RV reducer;Vibration test;Vibration signal;Time domain analysis;Frequency domain analysis
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发布时间：2022-10-20 - 摘要：The subway gearbox is a key vehicle transmission parts,its vibration condition affects the safety operation of the train. The dynamic response of the subway gearbox is studied,taking the physical model of the subway gearbox as the research object,the data conversion of the Cero and ADAMS data interface is carried out,and the gearbox is flexible by means of ANSYS. The rigid body is replaced by the flexible body,and make reasonable restraint to it. The model of gear contact is established,and the bearing pair is built by ADAMS built-in mechanical package module,and the rigid-flexible coupling dynamics model of subway gearbox is established. According to the simulation results of the gearbox dynamics analysis,the analysis of the box in the gear start and the acceleration phase there is a large vibration impact,and compare the stress and strain of the measured point of view,the upper box is significantly more than the box. The vibration response of the upper box and the upper part of the upper box are affected by the signal superposition and so on,the stress response can be considered. It is possible to consider the optimization of the box structure,consider adding the reinforcement and other measures to strengthen the dangerous node stability. It provides references for the design of subway gearbox.关键词：Subway gearbox;Vibration response;Rigid-flexible coupling model
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发布时间：2022-10-20 - 摘要：The wheel-legged robot has the advantages of fast moving velocity of wheeled robot and strong passing obstacle capability of legged robot,and it is the development direction of new type mobile robot. A kind of wheel-legged mobile robot based on 3-PUU parallel mechanism is presented. It has advantages of simple structure,high stiffness and strong carrying capacity. The leg walking gait of 3-PUU wheel-legged mobile robot is analyzed. The wheel and leg switch principle and the steering principle under wheel type mode are explained.The stability of robot moving on the road surface is analyzed according to the calculation of gravity,and the maximum step is determined. The trajectory equation is derived by using three spline interpolation and the variation rules of displacement,velocity and acceleration are obtained by using Matlab software. The simulation results show that the robot can achieve continuous and stable walking. The robot can be used in the rescue tasks such as underground coal mines and other dangerous environments.关键词：Mobile robot;Wheel-legged robot;3-PUU;Gait;Stability
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发布时间：2022-10-20 - 摘要：The rack test device for the Three Gorges ship lift is mainly composed of four parts: driving gearbox,driving gear-rack,loading gear-rack and loading gearbox. In order to better calculate and analyze the transmission efficiency of the rack test device,through the establishing gearbox transmission efficiency calculation model,transmission efficiencies of the four parts and the transmission efficiency and the power consumption of the total whole unit are calculated respectively,the calculation results are contrastive analyzed by the input speed and torque,output speed and torque of the test data,the accuracy of calculation model and test data is verified,the research basis of transmission efficiency of gearbox and gear rack for low speed and load duty is established.关键词：Ship lift;Rack;Gearbox;Transmission efficiency
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发布时间：2022-10-20 - 摘要：Taking a manual transmission as research object,a simulation analysis model of transmission gear rattle is conducted by using the SIMdrive software,this model considering the influencing factors such as input shaft speed fluctuation,clearance,inertia of loose gear and drag torque,and these influence factors are used to calculate the angular velocity of each loose gear and the engaging force of each idler gear pair. The transmission gear rattle is tested and the loose gear speed signals are measured to verify the effectiveness of the simulation analysis model. From the point of view of the impact energy,the derivative of the idler gear on the meshing force is taken as the rattle index（ Jerk index）,and using the forward difference method to solve the Jerk index under various conditions. The partial derivative of the four parameters of speed fluctuation,clearance,inertia of loose gear and drag torque are obtained respectively,and the sensitivity of each parameter to the transmission gear rattle is obtained. It is found that the sensitivity of the speed fluctuation to the rattle is always positive,and when the speed fluctuates at 40 r/min,the influence on the gear rattle starts to increase sharply.When the clearance is less than 0. 1 mm,the rattle sensitivity is positive,more than 0. 1 mm when the negative.The sensitivity of the inertia of loose gear is always negative,and when the inertia is more than 0. 000 6 kgm2,the rattle sensitivity value is almost unchanged and the effect of the change in inertia on the gear rattle is not noticeable. When the drag torque is less than 0. 6 N·m,the rattle sensitivity is negative,more than 0. 6 N·m when the positive,and at 0. 2 N·m to 0. 3 N·m between the drag torque on the gear rattle is not noticeable.关键词：Transmission;Gear rattle;Evaluation index;Sensitivity
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发布时间：2022-10-20 - 摘要：The lubrication model of the slope-platform pad thrust bearing with different structural parameters are built,the effects of the slope angle,oil film thickness and angular speed on bearing temperature field are studied. And the effects of the speed on the load capacity of the bearing is also analyzed under conjugate heat transfer circumstance,which provide the theoretical guidance for design and use of thrust bearing. The results show that the maximum temperature of the bearing pad appear in the circumferential outlet and near the outer diameter side,which decreases with the increase of the slope angle. When the other conditions are constant,the larger the thickness of the oil film is,the lower the temperature rise of bearing,and the film thickness does not affect the temperature field distribution of the bearing. The shear stress and bearing temperature are increased with the increase of speed. There is no longer a linear relationship between the axial bearing capacity and speed when considering the coupling heat transfer.关键词：Oil film thickness;Slope angle;Temperature field
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发布时间：2022-10-20 - 摘要：Aiming at the problem that the manipulator operate the flexible load which is constrained by operating environment which the binding force and the load deformation are not easy to control. According to the theory of deformation screw,the dynamics model of the system which manipulator operate the flexible load is established by combining the Lagrangian equation. The system is decomposed into two subsystems: the rigid manipulator and the flexible load. Their dynamics equations are established respectively. According to the constraint relation between the flexible load and the environmental binding force and the end of the manipulator,the motion equation of the system is deduced. In the case of the operating state of a given manipulator and the environmental binding force or the desired trajectory of each joint drive torque and load end of a given manipulator,the inverse kinetics model and the forward dynamics model of the system are deduced. The effectiveness of the proposed method is verified by a 3 DOF manipulator operate a flexible beam.关键词：Flexible load;Deformation screw;Limited movement;Dynamics
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发布时间：2022-10-20 - 摘要：When the roller bearings are in the early stage of failure,the characteristic signal is weak and it is affected by the interference noise,which makes the fault feature difficult to extract. In order to solve this problem,a fault diagnosis method based on the combination of local mean decomposition（ LMD） and maximum correlated kurtosis deconvolution（ MCKD） is proposed. Under the strong noise environment,LMD is difficult to extract the characteristic of weak fault signal,therefore,a set of PF components that are decomposed by LMD which use the correlation coefficient and kurtosis value select sensitive component for signal reconstruction. Then MCKD is used to filter and it is used to highlight the pulse of fault signal. Finally,according to the signal envelope power spectrum,the fault characteristic frequency is extracted,the effectiveness of the method is proved by some simulation and application examples.关键词：Rolling bearing;Fault diagnosis;Local mean decomposition;Maximum correlation kurtosis deconvolution
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发布时间：2022-10-20 - 摘要：The thermoelastrohydrodynamic lubrication performances of misaligned journal bearing considering surface morphology,thermal effect and variable density and variable specific heat are studied. The lubrication analysis of bearing is carried out by using average flow mode based generalized Reynolds equation. The temperature field is calculated by energy equation and heat conduction equation. The results show that the effects of variable density and variable specific heat on the bearing capacity and maximum film pressure of misaligned journal are obvious when eccentricity ratio is large. The maximum film temperature is increased and power loss is decreased when considering variable density. The maximum film temperature is decreased and power loss is increased when considering variable specific heat. The higher the speed is,the greater the effect of variable density and variable specific heat on the lubrication performance is. The lubrication parameters of bearing when considering variable density and variable specific heat are obviously different from those when considering variable density or variable specific heat. The smaller the clearance is,the greater the effects of variable density and variable specific heat on the lubrication performance. In order to accurately predict the lubrication performance of bearing,the influence of variable density and variable specific heat capacity need to be considered.关键词：Variable density;Variable specific heat;Misaligned journal;Lubrication;Bearing
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发布时间：2022-10-20 - 摘要：Aiming at the shortage that the workspace of planar parallel mechanism with two degrees of freedom is small,a 5 R mechanism of variable drive layout of large workspace is presented. On the basis of kinematics analysis,3 D kinematics simulation analysis model of parallel mechanism is built by using the SolidWorks. The motion trajectory and workspace of the parallel mechanism are solved by changing the motion parameters of cranks in the environment of Motion analysis. The forward solution analysis is completed. In addition,the kinematics experimental platform of parallel mechanism is built. The required trajectory can be drawn in Solid Works. Two servo motors’ speeds of any time can be obtained by inverse solution of Solid Works. Combined with the motion control functions,the running program of PC is written. The servo motors are controlled by PCI-DMC-F01 motion control card. Therefore,the end effector can move along the desired trajectory. The experimental trajectory and workspace are in accord with the results of the forward and inverse solutions. The experimental results show that the forward and inverse solution of 5 R mechanism is correct and feasible. In addition,on the basis of it,the application example of parallel mechanism with large workspace is provided. This research has reference value for the engineering application of 5 R parallel mechanism.关键词：5R mechanism;Variable drive layout;Workspace;Motion trajectory;Forward and inverse solution
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发布时间：2022-10-20 - 摘要：In order to realize the fast braking of motor vehicle at high speed and high load,the working principle of the existing braking system of mine electric locomotive and the problems in the process of braking are analyzed. The braking system of 6 tons of mine electric locomotive is designed,by using a caliper disc brake,and the main components structure sizes of brake disc,brake and drive mechanism are analyzed and calculated,according to the structure design of the brake and the calculated size,the simulation analysis of temperature field of the motor vehicle braking process is carried out by using the finite element simulation software.The temperature distribution cloud and the temperature distribution variation and the maximum temperature in the braking process of brake disc under the different adhesion coefficient are obtained. The simulation results meet the provisions of the motor vehicle industry brake temperature requirements. Finally,the designed electric locomotive is tested and analyzed,the synthetic results of simulation and test reveal the rationality of the brake design.
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发布时间：2022-10-20 - 摘要：According to the non-stationary and nonlinearity of the fault signals from rolling bearing,a recognition method based on Modified Ensemble Empirical Mode Decomposition（ MEEMD） and Double Hiddenlayer Elman Neural Network（ DHENN） is proposed. The vibration signal is decomposed by MEEMD,and using variance contribution to select out the Principal Intrinsic Mode Function（ PIMF）,one can calculate the permutation entropy of the IMF which obtained by using Complementary Ensemble Empirical Mode Decomposition（ CEEMD）,it is basic to deal with the illusive component,and the others are reconstructed and decomposed by using EMD,the variance contribution is calculated,through Hilbert transform,characteristic matrix is constructed. The DHENN network model is constructed to recognize the fault type,getting the best combine of the double hidden neural network. Finally,compare EMD-DHENN and MEEMD-ENN,the result show that the proposed MEEMD-DHENN method has a high accuracy rate of 100% and only need 26 steps.关键词：Rolling bearing;Fault diagnosis;MEEMD;DHENN
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发布时间：2022-10-20 - 摘要：Comparing with the mechanical gear contact transmission,magnetic gear is a new transmission device with a novel structure and a broad development prospect. The large torque transmission is achieved by using the magnetic field modulation principle. On the basis of the traditional magnetic gear structure,the inner and outer rotor permanent magnets are improved,which the inner permanent magnets are triangular-fan-shaped phase and the inner and outer permanent magnets are Halbach arrays. The two dimensional（ 2 D） finite element（ FE） method is used to simulate the modified magnetic gear model,and the electromagnetic field and electromagnetic torque of the magnetic gear are calculated. At the same time,the magnetic field and torque are compared with the conventional magnetic gear. The simulation results show that the output torque of the improved magnetic gear is greatly than the traditional magnetic gear,which can effectively enhance the air gap magnetic density and reduce the air gap harmonic content. It is a great significance to study and apply the torque density of concentric magnetic gear.关键词：Magnetic gear;Magnetic field modulation;Air-gap flux density;Electromagnetic torque
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发布时间：2022-10-20 - 摘要：In order to solve the fault recognition problems caused by a complex signal transfer path,severe noise pollution and the weak fault features,a method for gear based on variational mode decomposition（ VMD）and adaptive neuro-fuzzy inference system（ ANFIS） is proposed. Firstly,VMD is used to decompose a fault signal into several intrinsic mode functions（ IMFs）,and introduced the permutation entropy to construct the feature vectors characterizing the modal component information. Then the extracted feature vectors are input into the adaptive neuro-fuzzy inference system to establish the fault diagnosis model. Finally,the model is validated by the vibration signal data of the gears and compared with the support vector machine（ SVM） method. The results show that the proposed method has a strong learning ability and it can effectively diagnose the gear fault,improve the accuracy of fault identification. The recognition effect is obviously superior to SVM.关键词：Variational mode decomposition;Adaptive neuro-fuzzy inference system;Gear;Permutation entropy;Fault diagnosis
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发布时间：2022-10-20 - 摘要：A new type two-dimensional gearbox with the output of rotating and reciprocating motion and transmission principle are proposed. The physical model of the two-dimensional gearbox is constructed by using the three-dimensional modeling software Inventor. The reciprocating motion related assembly is designed by applying the method of double eccentricity amplitude adjustment and eccentric wheel structure characteristics,the working principle of the output shaft rotation and axial reciprocating motion mechanism is mainly studied. The kinematics analysis of the model is carried out in software ADAMS and the output characteristics of the axially reciprocating assembly motion are obtained. Based on the theory above,the prototype of the two-dimensional gearbox is developed and manufactured. The plastic extrusion experiment is carried out by mounting the prototype on a single screw extruder. The rationality and feasibility of the two-dimensional gearbox with the output shaft rotation and reciprocating motion are verified.关键词：Two-dimensional gearbox;Output shaft;Screw extruder;Axial reciprocating motion;Simulation
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发布时间：2022-10-20 - 摘要：The groove wheel mechanism has the characteristics of intermittent movement and large transmission ratio,it is widely used in the machine system of projector,machining center and packaging machine.But with the increase of the rotation ratio,the groove wheel mechanism can’t run smoothly. In order to solve this problem,on the basis of the original groove wheel mechanism,an auxiliary locking wheel is added to realize the smooth operation of the groove wheel mechanism under the large turning and stopping ratio. By using Solid Works three-dimensional software,the three-dimensional model of the groove wheel mechanism is established,combined with the virtual prototype software ADAMS,the motion simulation of the groove wheel mechanism is carried out,the stability conditions of the whole transmission process under the condition of large-turn-stop ratio are proved.关键词：Groove wheel mechanism;Adams;Motion simulation;Stability condition
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发布时间：2022-10-20 - 摘要：The gear weak fault signal is easy to be covered by the strong fault signal in a complex fault,and there will be missed diagnosis phenomenon. The the feature extraction of weak fault under gear complex failure is studied. Firstly,Multipoint Optimal Minimum Entropy Deconvolution Adjusted（ MOMEDA） is used as the pre-filter to denoise the original signal and enhance the periodic impact components in the signal. Then,the Hilbert transform is used to obtain the envelope spectrum. By analyzing the obvious frequency components to identify the fault,the extraction of weak fault characteristics is achieved. Simulation example of fault signal and transmission shows that this method can effectively realize the feature extraction of gear weak fault.关键词：Gear;Multipoint optimal minimum entropy deconvolution adjusted;Weak fault;Feature extraction
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发布时间：2022-10-20 - 摘要：In order to solve problems that the traditional demodulated resonance technology is difficult to determine the parameter of the band-pass filter and greatly influenced by noise,an adaptive demodulated resonance based on EEMD,information entropy and fast kurtogram is presented. Firstly,the original signal is decomposed into several IMFs,and the signal is reconstructed by using the correlation coefficient method to highlight the fault characteristic signal. Then,select the minimum information entropy of IMF to spectral kurtosis analysis and the central frequency and bandwidth of the band-pass filter is determined. Lastly,the filtered reconstructive signal is analyzed by using the Hilbert envelope spectrum analysis. The numerical simulation signal and measured gear fault signal test show that the fault characteristic is highlighted by using the proposed method and the validity is proved.关键词：EEMD;Information entropy;Spectral Kurtosis;Adaptive demodulated resonance
- 4
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- 180
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- 2
发布时间：2022-10-20 - 摘要：With the requirements of hardware-in-the-loop（ HIL） test of dual clutch Automatic transmission（ DCT） control unit（ TCU）,the real time simulation model of DCT is built based on Matlab/Simulink,mainly containing shift fork position,clutch torque,transmission torque and speed synchronization calculation modules,etc. The functional fault model module is developed on the basis of the real time model to realize the simulation of mechanical failures. The built DCT model is integrated into the whole vehicle model,a closed loop is constituted with real TCU,and the DCT model is validated online. The built model can be effectively used for the function and fail-safe testing of DCT-TCU.关键词：Dual clutch;Real time simulation;Model;Automatic transmission;Hardware-In-The-Loop
- 4
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- 134
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- 4
发布时间：2022-10-20 - 摘要：A new arc guide rail measurement simulator is introduced,the finite element model of this simulator is established by using the software ANSYS Workbench. A bearing equivalent stiffness treatment method adjusted to finite element program is introduced. The maximum stress and deformation are obtained by statics analysis,and the results could provide data support for structure improvement and weight reduction. The natural frequency and vibration type of measurement simulator in different condition are obtained by modal analysis,and the working reliability of it is proved.关键词：Measurement simulator;ANSYS Workbench;Equivalent treatment;Statics analysis;Modal analysis
- 3
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- 110
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- 0
发布时间：2022-10-20
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