最新刊期
期 7 ， 2016
- 摘要：Comparing with straight tooth synchronous belt,the double helical synchronous belt has the characteristics of high transmission accuracy,low noise,smooth running. The wear of tooth surface is mainly caused by partial meshing interference in the process of synchronous belt transmission. In order to study the effect of partial meshing on the double helical synchronous belt tooth surface interference,by using the coordinate transformation theory,the partial meshing transmission model is established under the quasi- static condition. The model of partial meshing interference morphology is established through the research of the double helical synchronous belt partial meshing mechanism. In addition,the influence of pitch difference and spiral angle on the process of double helical synchronous belt tooth surface interference and the morphology of instantaneous interference are studied. The double helical tooth and straight tooth wear experiment and calculation results show that the double helical synchronous belt has better resistant wear and performance.关键词：Double helical synchronous belt;Partial meshing;Interference;Tooth surface wear;Inter-ference morphology
- 3
- |
- 131
- |
- 1
发布时间：2022-10-20 - 摘要：The actual tooth surface equation is established considering the worm wheel installation errors based on a five- axis linked CNC grinding machine. The tooth contact analysis（ TCA analysis） on the actual tooth surface of face gear and pinion tooth surface is investigated,and the solving method of contact point path of the face gear pair is obtained. The TCA analysis indicates that the tangential and axial linear position errors can cause deviation of the tooth surface along the tooth width and tooth height directions,also the contact point path has a larger deviation along the tooth length direction. The yaw angle errors can cause the tooth surface to incline along the tooth length direction,and there exists a bigger deviation as well as inclination along the tooth length direction. The pitch angle errors will cause the tooth surface to rotate along the tooth height direction,and the contact point path will rotate at the same time. The contact point path of face gear pair is much more sensitive to the four kinds of worm wheel installation errors. A theoretical reference for the error tracing in the face gear designing and manufacturing and the real tooth surface contact analysis is provided by the research.关键词：Face gear;Grinding machining;Worm wheel installation error;Actual tooth surface;Tooth contact analysis
- 4
- |
- 208
- |
- 3
发布时间：2022-10-20 - 摘要：In order to making the tooth profile of bevel gear be close to its theoretical spherical involute,a design method of the tooth profile of bevel gear using conical involute is proposed,that is forming the involute tooth profile of bevel gears on the back cone surface directly. The conical involute can be expanded on plane,so the design and manufacturing of bevel gear become convenient. The mapping relation between plane involute of equivalent gear and conical involute are established by using the method of converse expansion,and the parameter equation of conical involute is derived in a rectangular coordinate system. The tooth profile of bevel gear is created by using the derived conical involute equation,and the parametric model of bevel gear is generated based on the conical involute eventually,the modeling accuracy is analyzed,the feasibility of the modeling method is verified.关键词：Bevel gear;Conical involute;Parameter equation;Converse expansion method
- 4
- |
- 125
- |
- 1
发布时间：2022-10-20 - 摘要：Taking the disc cams with translating roller follower study object,the organization form,basic /general dimension,accurate description and basic steps for dimension synthesis are given,the coordinate system O- rr0 e and area dimension space Ω（ r0,r,e） of dimension are constructed,then discretizeing and gridding of the dimension area is carried out. The four constraint conditions and analytical expressions are put forward,through single or merge visualization- oriented mapping with ergodic method,the corresponding boundary and solution domain are given. Then,according to the multi objective planning and visualization- oriented mapping,it shows some important rules such as carinal dot Piek*/ crest line lek/ crest plane Sback and the bottom dot Pek**/ valley dot P***,it also reveals the existence of optimal solution. All the consequences are instructive to the dimension synthesis of the mechanism.关键词：Translating follower;Disc cam;Dimension synthesis;Visualization-oriented mapping;Bottom dot;Valley dot
- 2
- |
- 51
- |
- 2
发布时间：2022-10-20 - 摘要：According to the meshing and forming principle,the tooth surface equation of spiral bevel gear is established. The spiral bevel gear loaded contact analysis is carried out by using finite element method,and the contact positive pressure,relative sliding speed and friction coefficient of the tooth surface 10 meshing points are obtained. By applying heat transfer theory and based on the analysis of the friction heat and the heat conduction parameters,the finite element model of the unsteady temperature field of spiral bevel gear is established,and the simulation analysis of the tooth surface temperature field distribution and its variation with time during the dry running is carried out. The results show that during the initial stage of the dry running of the spiral bevel gear,with the increasing of the meshing period,the tooth surface temperature rising rapidly,and then rising slowly,the temperature rising is accompanied by fluctuations which correspond to the meshing cycle. The increasing of the meshing speed prolongs the time that temperature rise rapidly,and it leads more significant temperature rising at the same time.关键词：Dry running;Spiral bevel gear;Temperature field;Finite element method
- 3
- |
- 162
- |
- 3
发布时间：2022-10-20 - 摘要：According to the performance requirements under the condition of small attachment coefficient,the speed control strategy is built in the hybrid electric vehicle equipped with electric- mechanical continuously variable transmission. In the start- up phase of vehicle,the start- up mode can be determined by analyzing the battery state of charge（ SOC）. Under the working condition of speed up climbing and in different start- up modes,the CVT ratio control under the condition of small attachment coefficient can be decided through the demand torque,and by this CVT ratio control to insure the vehicle driving wheel without slipping phenomenon under the condition of the accelerator fully open. The speed control strategy is built in MATLAB / Simulink /Stateflow and simulated in CRUISE which vehicle model is built. The simulation results shows that torque of driving cycles gets a reasonable distribution with this shifting strategy,and vehicle dynamic property promotion is gotten.关键词：Electric-mechanical control CVT;Hybrid electric vehicle;Small attachment coefficient;Speed control strategy for dynamic property
- 3
- |
- 84
- |
- 2
发布时间：2022-10-20 - 摘要：The precise gear model is built by the method for composite modeling with MATLAB and APDL. The key friction characteristic parameter is acquired by test. The tooth surface friction coefficients are inversely analyzed by numerical simulation and intergeneration projection genetic algorithms（ IP- GA） under different lubrication conditions. The problem of complex tooth surface friction coefficients is solved reasonably.Compared with traditional method,the actual tooth friction conditions are simulated,then the result is more reasonable. Exactly inverse analysis of tooth friction coefficients can help to numerical simulation and improve dynamic performance of gear transmission and to upgrade the level of design and manufacture of gear.关键词：Friction coefficient;Genetic algorithm;Inverse problem;Gear
- 3
- |
- 44
- |
- 0
发布时间：2022-10-20 - 摘要：In order to offset load torque,many weight- bearing lower extremity exoskeleton install gas spring in the hips which make the human walk abnormally in single leg support phase due to the disappearance of the rotation junction. To solve this problem,aiming at the exoskeleton robot " ELEbot" designed by east China University of Science and Technology,by using the screw theory,the " ELEbot" degrees of freedom and constraints in the single leg support phase are calculated and determined and then an improved mechanism to meet demand for degrees of freedom in this posture is put forward and the rationality of the drive configuration is verified. Through ADAMS software,the simulation analysis of the building model is carried out,This simulation come to the conclusion that the simulation result is consistent with the theoretical calculation,the feasibility of the optimization mechanism is proved.关键词：Weight-bearing exoskeleton;Screw theory;DOF analysis;Adams
- 3
- |
- 282
- |
- 5
发布时间：2022-10-20 - 摘要：The 3- RRRS mechanism is adopted to connect motion platform with static platform,which can achieve the 6 dimensions change of pose for static platform relative to moving platform. Releasing S vice,the mechanism configuration can be used for the general structure of reptiles bionic robot. Because the mechanism configuration has redundant drive characteristics,it can improve motion performance and work space of motion platform. The forward kinematics problem is studied. Firstly,according to the structure relationship,the motion equations including redundant drive variables are established. Secondly,the redundancy drive variables are solved by Bezout equation and variable substitution. Finally,a calculation model of the motion trajectory and direction matrix for motion platform are obtained. An analysis example is described. A reference for solving the similar problem is provided.关键词：3-RRRS mechanism;Redundant drive;Forward kinematics;Bionic robot
- 3
- |
- 66
- |
- 0
发布时间：2022-10-20 - 摘要：The influencing factors on continuously variable transmission（ CVT） power consumption and efficiency are studied. The external characteristic compare of engine and motor is analyzed. A method of measuring CVT power consumption and efficiency is presented by using a low power electric closed test bed. The experiments results show that,the torque loss mainly depended on speed ratio and system pressure,and the efficiency mainly depended on speed ratio and primary input torque. When the ratio is less than 1,the torque loss increased significantly and the efficiency declined rapidly. When the ratio is larger than 1,the torque loss and efficiency are almost constants. Overall efficiency optimization control strategy,clamping force slip rate control algorithm and new electric oil pump are studied to determine the energy conservation potentials. The simulation results show that the three methods could improve economical efficiency by 3. 2%,5. 8% and 2. 4% individually. By adopting all the three methods,the economical efficiency improved 9. 8%. So the references for selecting and evaluating power conservation methods are provided.关键词：Automobile;Continuously variable transmission;Power consumption;Efficiency
- 4
- |
- 127
- |
- 3
发布时间：2022-10-20 - 摘要：As a crucial kinematics index for main manipulator performance,the workspace needs to be considered in design,control and application,it represents the main manipulator action range,and the working performance of main manipulator is discussed from the aspects of geometry. The functional relationships between robotic end- effector space position and variables for robotic joints are obtained through the main manipulator forward kinematics solution calculation,a simulation of main manipulator workspace is conducted by adopting numerical,graphical method and analytic method in the Matlab. According to the position information of collecting by 3D electromagnetic tracking system,through the quantitative and qualitative analysis,the correctness of the simulation method for solving the main manipulator workspace is verified. Finally,according to the shape volume of workspace,the location layout of the main manipulator on the operation table is decided,meanwhile,meanwhile,the characteristics and applications of the three kinds of main manipulator workspace solving methods are given,a basis for the kinematics performance index evaluation and preoperation surgical planning is provided.
- 5
- |
- 81
- |
- 1
发布时间：2022-10-20 - 摘要：The traditional ant colony algorithm in the process of mobile robot path planning,the algorithm is easy to fall into the local optimization problem when the convergence of the algorithm. Aiming at this problem,a new ant colony optimization for mobile robot path planning method is proposed. Firstly,the mathematical model of the robot path planning is established. Based on this,the traditional ant colony algorithm is improved,and the local robot path information is introduced into the initialization of ant colony pheromone and the probability of path selection,which improves the convergence speed of ant colony algorithm and prevents premature. By introducing the crossover operation and adjusting the parameters of the ant colony algorithm,the algorithm can avoid local optimization. The simulation results show that the proposed method can significantly improve the optimal path search capability,the overall performance is better than the traditional ant colony algorithm.关键词：Mobile robot path planning;New ant colony algorithm;Mathematical model;Convergence speed;Local optimum
- 5
- |
- 326
- |
- 1
发布时间：2022-10-20 - 摘要：The mathematic model for the harmonic drive mechanism with multi- variable and nonlinear external disturbance is established,the system error is defined and virtual function is introduced gradually. The RBF neural network is employed to approximate the nonlinear part of the harmonic drive mechanism on- line.The dynamic surface controller is developed based on RBF neural network. The closed- loop system convergence is demonstrated with the Lyapunov stabilization theory,through the theory analysis and simulation results comparing with general PID control show that the proposed controller not only satisfies high performance position tracking,but also have good accuracy and stability,which effectively suppresses the influence of the harmonic drive mechanism like nonlinear external disturbance.关键词：Harmonic drive mechanism;Nonlinear external disturbance;RBF neural network;Dynamic surface control
- 3
- |
- 68
- |
- 0
发布时间：2022-10-20 - 摘要：Based on the fact that the carrying capacity cannot be made the best use of because of the large difference between safety factor of surface durability and bending strength,and the large calculation caused by the many design parameters during the aero- engine double helical gear transmission design,the minimum weight and difference between each gear’s safety factor of surface durability and bending strength are taken as the objective functions. The design parameters which are important to the objects are chosen as optimization variables based on parameter sensitivity analysis method. Finally,the optimization solution is carried out by using the NSGA- Ⅱ. The results of optimization design show that the method promoted can effectively reduce the difference of the safety factors and the weight of the transmission system.关键词：Double helical gear;Multi-objective optimization;Parameter sensitivity analysis;NSGA-Ⅱ
- 4
- |
- 154
- |
- 2
发布时间：2022-10-20 - 摘要：In order to realize the function of the working station automatic turning and resetting,the multi station rotary automatic turning and resetting mechanism which is powered by cylindrical cam is proposed. Each working station is composed of a crank slider mechanism,the displacement of the slider is controlled by the change of the cam curve which drives the rotation of the crank and completes the turning of the working station.The mathematical model of this mechanism is established,through the variation of the design parameters can meet the requirements of different engineering requirements. In order to research the structure of multi station automatic turning and resetting mechanism fitting the empty request,the case of automatically empty the prefabricated hard cigarette is used as an example. The optimization of the automatic turning and resetting mechanism which is multi- objective is carried out. The minimum cam lift and vertical height,the maximum flip angle are the objective. The independent variables of this optimization are the parameters,such as the length of the crank and the connecting rod,the cam lift and so on. The optimization effect is obvious,and the rationality of the design parameter is verified by the simulation analysis.关键词：Automatic turning and resetting;Crank slider mechanism;Automatic emptying device;Cylindrical cam
- 5
- |
- 171
- |
- 1
发布时间：2022-10-20 - 摘要：The magnetorheological fluid transmission device power transmission mechanism is analyzed according to the Bingham model,and a disk- type magnetorheological fluid transmission device is designed. By using finite element analysis software Ansoft Maxwell,the magnetic circuit design and magnetic field simulation are carried out and the magnetic field distribution nephogram is obtained. A magnetic field tester is built,on which the magnetic field is tested. This transmission device is able to meet the working requirements,and the foundation for the next experiment is laid.关键词：Magnetorheological fluid;Transmission device;Magnetic field simulation;Magnetic field test
- 3
- |
- 202
- |
- 1
发布时间：2022-10-20 - 摘要：One key of quadruple- arc gear form grinding is to calculate the grinding wheel cross- section shape. Firstly,a coordinate system is built depend on form grinding principle. Through the quadruple- arc gear tooth surface equation and gear tooth surfaces in contact with the grinding wheel surface condition,the grinding wheel cross- sectional shape is obtained by using space coordinate transformation. Finally,by using MATLAB software computing and graphics capabilities to calculate and simulate the grinding wheel cross- section shape. The grinding wheel cross- section shape is verified by processing experiment.关键词：Quadruple-arc gear;Form grinding;Grinding wheel cross-section shape;MATLAB simulation
- 3
- |
- 76
- |
- 2
发布时间：2022-10-20 - 摘要：When the gear rack drilling rig for slant drilling is working,string collar need to accurate alignment through certain angle of tilt and different position,and move up and down relative to the derrick,the oilwell string makeup and breakout device such as the traditional hydraulic tongs and iron roughneck is not suitable for it. Focused on the technical problem,the track clamp system which can track freely along the rig derrick is proposed,its jacking system and hydraulic control system are designed. Based on bond graph theory,the mathematical model of track clamp jacking system is established,and the dynamic equation is derived. Based on the20- Sim software,the dynamic simulation analysis is carried out,the rationality of the bond graph model is validated,and the causes and effects of the system dynamic characteristics are analyzed,which provide technical support and theoretical guidance for the research and control of track clamp jacking system.关键词：Slant drilling;Jacking system;Power bond graph;Dynamic equation;Simulation
- 6
- |
- 115
- |
- 2
发布时间：2022-10-20 - 摘要：In order to improve the transmission performance and efficiency,the mathematical model is established based on the main design parameters of multi- axis micro- cultivator gearbox. Then the optimization program of the key design parameters is programmed combining the SGA,the NSGA- Ⅱ with MATLAB language. Finally,the mathematical model are optimized using this program and the optimization results are compared. The optimization results show that volume decreased respectively by 14. 13% and 15. 96% and coincidence degree are improved respectively by 4. 07% and 4. 60% by using the SGA and the NSGA- Ⅱalgorithm optimization. A good optimization effect is got and the NSGA- Ⅱ algorithm is better.关键词：Micro-cultivator gearbox;SGA;NSGA-Ⅱ;Multi-objective optimization
- 2
- |
- 112
- |
- 4
发布时间：2022-10-20 - 摘要：In the ultrasonic honing processing,design of the transformer composed of horn and processed gear is a key technology,it is very important to explore the new type of transformer. Based on variable cross-section composite horn wave equation of longitudinal vibration and displacement equation of medium thickness circular plate in flexural vibration,the resonance frequency equations of the system are derived according to the non resonant and boundary condition of the ultrasonic gear honing composite transformer composited of composition horn and medium thickness circular ring. The design parameters,the resonance frequency and the amplitude distribution of horn and ring are studied by using numerical calculation method,at the same time,the influence of the transformer geometric parameter on the system resonance frequency is analyzed. The result shows that,the finite element analysis of the resonant frequency and the calculated results are basically consistent with the theoretical calculation result and experimental test,the system resonance frequency decreases with the increase of the length of the composite horn,When the radius ratio of the composition horn two ends and the length of the paragraphs remain unchanged,the system resonance frequency increases with the increase of both ends radius is proportional,it increases with the increase of ring thickness radius ratio when other parameters are constant. The results not only confirmed the correctness of the non resonance theory but also provides a theoretical basis for design and application of ultrasonic gear honing transformer.关键词：Mindlin medium thickness plate theory;Resonant frequency equation;Ultrasonic gear honing composite transformer
- 4
- |
- 57
- |
- 2
发布时间：2022-10-20 - 摘要：Currently,it is difficult to set up an accurate model for the multi- ridge globoid cam with complex curved surface in automatic tool changer（ ATC）. Taking the geometric theory in globoidal cam as basis,the contour surfaces program of each roller in different movement period are written according to the meshing situation between the driven plate roller and the globoidal cam. And then the curves are merged and the contour surfaces are obtained by using curve and surface function in Pro / E. The normal offsets of theoretical contour surfaces are conducted,and a new accurate cam solid model is obtained. At last,the virtual prototype of the globoidal cam mechanism is built by using ADAMS,through the motion simulation and analysis,the accuracy of the model is verified.关键词：Multi-ridge globoid cam;Pro/E;3D Modeling;Virtual prototype
- 7
- |
- 189
- |
- 2
发布时间：2022-10-20 - 摘要：Because the conventional controller for parallel mechanism has low trajectory tracking precision,the sliding mode variable structure controller（ SMC） is designed based on the dynamics equation of 3-RPS parallel mechanism and proportional switching control law. Firstly,the Matlab / Sim Mechanics analysis model of 3- RPS parallel mechanism is established,the Jacobian matrix of 3- RPS parallel manipulator is solved by using the micro- displacement method and the optimal size parameters of the mechanism are determined by workspace analysis,which are the theoretical reference values for control system. Secondly,the SMC controller is established,the stability of SMC controller is proved by using the Lyapunov function. At last,the Matlab / Simulink block diagrams of PID controller and SMC controller are respectively established,the effects of PID controller with SMC controller are compared and analyzed,the results show that the trajectory tracking precision of SMC controller is higher than the PID controller,and the SMC controller has smaller steady- state error,faster response speed and better robustness,and the effectiveness of the SMC control is verified.关键词：3-RPS parallel mechanism;Micro-displacement method;Workspace analysis;PID control;SMC control
- 4
- |
- 164
- |
- 1
发布时间：2022-10-20 - 摘要：The hydraulic lower exoskeleton rehabilitation device is proposed to solve the problem of patient lying on the bed can’t walk and the aged leg rehabilitation training. Two kinds of transmission schemes are put forward as its main transmission mechanism,which are crank- slider mechanism and slider- rocker mechanism. With the main construction member motion analysis of the crank- slider mechanism and slider- rocker mechanism,the main technical parameters are obtained. And the displacement,velocity and acceleration of the components are acquired and compared simultaneously. Then the slider- rocker mechanism is determined as the main transmission mechanism of the hydraulic lower exoskeleton rehabilitation device. Finally,the three dimensional assembly model of the legs rehabilitation device is established with Solid Works,and the simulation and mechanics analysis are conducted. The results show that the proposed hydraulic legs rehabilitation device can achieve the expected movement purpose and meet the requirements of rehabilitation training.关键词：Rehabilitation training;Crank-slider mechanism;Slider-rocker mechanism;Simulation analysis
- 3
- |
- 196
- |
- 1
发布时间：2022-10-20 - 摘要：By taking a high speed printing machine as a study example,on condition that allowable pressure angle is satisfied,there is a corresponding maximum value（βm）maxof travel angle of rocker βmexist when an appropriate initial angle of rocker θ50 is given,according to this,whereby search,the optimal initial angleθ*50,（βm）max*and（βm）maxvalue domain-( 0,（βm）max*]are solved. The connotation of the mechanism dimension synthesis task of high speed printing machine is enriched and expanded. It has important theoretical value and practical engineering significance to design better and optimal dimension parameter mechanism.关键词：High speed printing machine mechanism;Output member;Initial angle;Travel angle （βm）maxvalue domain
- 3
- |
- 36
- |
- 1
发布时间：2022-10-20 - 摘要：A new algebra algorithm for the forward position kinematics of general Stewart platform（ GSP）is presented. First of all,the 20 original equations containing 9 variables are built according to the geometric construction of GSP. Then,the Groebner basis under the degree reverse lexicographic term ordering for the 20 equations is solved,and the 29 Groebner basis can be selected from it and compressing proper variable,the 2929 Sylvester matrix is constructed. A 40 th degree univariate equation is achieved from the determinate of the matrix. Finally,the total 40 solutions of the corresponding other variables can be obtained by back substitution method. A numerical example is deployed to verify the algorithm. The algorithm is also suitable for the forward position kinematics analysis of the other type of parallel- mechanism.关键词：Stewart platform;Forward position kinematics;Algebra algorithm
- 2
- |
- 105
- |
- 1
发布时间：2022-10-20 - 摘要：The transmission system is a very important precision mechanism for twin- screw pulping machine equipment. However,that problem with characteristics of multi- objective function and multi constraints cannot be resolved in traditional optimization methods well,the optimization design is carried out based on genetic algorithm. Taking the volume of transmission system as the objective function,the optimization design is carried out. The results,which gives global optimal solution instead of locally optimal solution in traditional methods are much better. Finally,through the comparing of the simulation optimization results,by using the optimized new design scheme,the machine can meet various performance and constraints and be tighter and more reasonable.关键词：Double screw pulping machine equipment;Transmission system;Optimization method;Genetic algorithm
- 3
- |
- 56
- |
- 2
发布时间：2022-10-20 - 摘要：In the view of meshing impact during the operation of food conveyor chain drive,based on Hertz contact theory,the amplitude and expression of the impact force of the driving sprocket are given by building the nonlinear spring damping dynamics model of meshing impact. With the help of dynamics simulation software ADAMS,the simulation and research of the meshing impact at different speed on the system is carried out,the change law of the contact force between the sprocket and the roller is obtained,and the simulation results meet with the actual working condition and high reliability. The compare between simulation results and theoretical calculation results prove the relative error between theoretical value and simulation value is reasonable,and the dynamics model is reliable.关键词：Food conveyor chain;Meshing impact;Hertz contact;Dynamics model;Adams
- 4
- |
- 233
- |
- 2
发布时间：2022-10-20 - 摘要：For fault diagnosis of rolling bearings,a new feature extraction strategy based on short time Fourier transform（ STFT） and bag of wordss（ BOW） is proposed. Based on the generate mechanism of bearing fault,the different bearing vibration signals have relevant energy distribution. But in the factory,some factors like signal interference or environment noise will destroy the energy distribution. When using BOW,it regards the distribution of energy in frequency domain each time frame as a word,so segments of signal will be documents which are made up of many words. It shows the energy distribution directly in data perspective. Then,with the new features and SVM classifier,the results of fault diagnosis can be known. At last,effectiveness of the proposed method is verified,vibration from SQI- MFS platform and CWRU platform are analyzed. The results in experiments shows that this method is better than RMS and WE&WEE. So the new feature can be used in fault diagnosis area.关键词：Fault diagnosis;Time-frequency domain feature;STFT;BOW;SVM
- 4
- |
- 288
- |
- 1
发布时间：2022-10-20 - 摘要：Considering the complex and changing load environment works characteristic of planetary gear transmission system of 2. 5 MW wind turbine caused by random wind speed,by using the two parameters Weibull distribution,the time- varying wind load caused by random wind speed is obtained. A Dynamics model of 2. 5 MW wind turbine planetary gear transmission system is built by using lumped- parameter method.Considering the internal excitation such as the time- varying meshing stiffness and bearing stiffness,the numerical method is used to simulate the dynamics performance of planetary gear transmission system for 2. 5 MW wind turbine. The vibration displacement and vibration velocity of components in system which are influenced by time- varying input torque are got. The research results can lay a good theoretical foundation for fault diagnosis and optimization design for wind turbine gearbox.关键词：2.5 MW wind turbine;Planetary gear transmission system;Random wind speed;Dynamics characteristic
- 4
- |
- 344
- |
- 1
发布时间：2022-10-20 - 摘要：In order to improve the transportation performance and reliability of chain conveyor,based on the silent chain meshing mechanism,a double pitch time sharing meshing silent chain is designed,and the related design parameters are given. Base on the ADAMS,a simulation model is established to compare with the tight edge fluctuation and meshing impact force of double pitch time share meshing silent chain and double pitch roller chain. As the result of the stimulation analysis shows,compared with double pitch roller chain,the meshing of double pitch time share meshing silent chain is stable and the tight edge fluctuation is reduced by 59%,while meshing impact force is reduced by 51. 9%. Then it is compared with results of bench test,on the confined fluid chain bench,the noise test and the 250 h wear test are conducted,compared with that of double pitch roller chain,the average noise at the tight side mesh point of double pitch time share meshing silent chain is reduced by 4. 6 d B and the wear elongation is reduced by 0. 28%. The experimental results prove that the rationality of double pitch time share meshing silent chain design is reasonable.关键词：Double pitch silent chain;Time sharing meshing;Tight edge fluctuation;Meshing impact
- 4
- |
- 69
- |
- 1
发布时间：2022-10-20 - 摘要：Based on the transmission housing which is designed independently by Automotive Engineering Technology Research Institute of Hefei University of Technology,the three- dimensional modeling of the housing is built by using Pro / E software,then imported in hypermesh saved as. DAT format after meshing. Then,the modeling is imported into the mechanical transmission system of the transmission which has already been established in the Romax Designer,and the combination of the flexible portion and a rigid model of the transmission system is achieved. And the natural frequency and vibration mode of the housing are obtained in the Romax Designer. The finite element calculation result is consistent with the result of modal test. The results of modal analysis can be used to the dynamic response analysis and dynamic strength design of the transmission.关键词：Transmission housing;Modal analysis;Modal test
- 3
- |
- 340
- |
- 1
发布时间：2022-10-20 - 摘要：Aiming at the analysis of the position and orientation error on the new 3- PRS parallel mechanism with three adjustable pedestals and variable working space,a geometric analytic method for the forward kinematics analysis of the 3- PRS parallel mechanism is proposed,then the analysis of the working platform end- effector error is derived,and what’s more,the position and orientation of the working platform end- effector is obtained by using software emulation when the three pedestals at different positions. The results show that the end- effector error has obvious changes with the different positions of the three pedestals. This study provides a useful guidance for the error compensation of the new 3- PRS parallel mechanism.
- 2
- |
- 185
- |
- 1
发布时间：2022-10-20 - 摘要：In order to understand the vibration of an automotive transmission system,taking the type automotive transmission as the research object,the vibration signal tests and analysis of the automotive transmission under multi- conditions are carried out,and a greater contribution to vibration frequencies of the transmission are obtained. Comparing the vibration frequency with the modal test results of the transmission,the frequency which is easy to cause the resonance of the transmission is confirmed. The results can lay a foundation for taking measures to avoid the resonance frequency,to reduce the vibration and the optimized design of vehicle structure.关键词：Transmission;Vibration signal;Modal test;Resonance frequency
- 4
- |
- 178
- |
- 1
发布时间：2022-10-20 - 摘要：The compliant micro- gripper is kind of mechanism used to amplify and transfer the micro-actuators displacement. The compliant mechanism accomplishes the transmission or transformation of motion,force and energy by the deformation of flexible components itself. The a fully compliant micro- gripper is designed and analyzed based on hinge stiffness. The gripper can achieve amplification of micro- displacement and ensure the output displacement with the horizontal direction. The relationship between the input force,input displacement and the output displacement of the compliant micro- gripper are established with the pseudo- rigid- body- model and virtual work. And the characteristics of the developed compliant mechanism are also modeled and analyzed with finite element method. The research indicates micro- gripper unilateral output displacement of up to 0. 989 mm when the material strength of the full compliant micro- gripper is limited the allowable range,and the conclusion of finite element simulation is consistent with the theoretical model. Transient behavior is continuous and smooth,and there is no mutation. It shows that the compliant micro- gripper has the good smoothness in the process of movement. By making and testing the prototype of compliant micro- gripper,the feasibility of this design is verified.关键词：Compliant micro-gripper;Stiffness;Finite element analysis;Test
- 3
- |
- 204
- |
- 1
发布时间：2022-10-20 - 摘要：A new type of designing scheme of spur gear differential used in vehicle drive axle is put forward,its operating principle and characters are analyzed in detail. According to the design project,the design and assemble of axle shaft gear,planet gear,planet carrier and others are created in Pro / E,and imported into ADAMS / View. Then the kinematic simulation and analysis of its two different working conditions of straight driving and handling driving are carried out. The analysis results show that spur gear differential not only can achieve automobile driving axle differential function,but also have advantage of simple construction and easy machining.关键词：Automobile driving axle;Differential;Spur gear;Kinematic analysis
- 5
- |
- 717
- |
- 4
发布时间：2022-10-20 - 摘要：Considering the milling force calculated by using mechanical model or milling finite element simulation is time- consuming and tedious,a prediction method of milling force based on the finite element simulation of oblique cutting is proposed. In this method,each cutting edge of the cutter is discretized into infinitesimal element of oblique cutting process. And through a series of oblique cutting process simulation,the relationship is fitted between the cutting force coefficients and cutting thickness. Then by geometric transformation,the obtained cutting force coefficient are applied in milling process,the instantaneous milling forces acted on the cutter are obtained finally. Comparing with the results of milling simulation,it shows that the finite element simulation method of oblique cutting can be applied to milling process,and the effectiveness of the proposed method is verified. Therefore,this method can be used for predicting cutting force in the processing of gear,and also provides a good foundation for researching surface integrity of gear machining.关键词：Milling force;Oblique cutting;FEM simulation;Cutting force coefficient
- 4
- |
- 83
- |
- 3
发布时间：2022-10-20 - 摘要：The principle of double- flank gear measuring is usually adopted by gear screening equipment in workshop. The real quality of gear transmission cannot be obtained because of the test result containing manufacture error in both sides of tooth. To solve this problem,a new type of gear comprehensive roll testing method is studied,combining the gear double meshing gear radial comprehensive deviation detection with the single meshing vibration noise detection,the quality of gear transmission can be comprehensively evaluated. The key techniques,such as automatically aligning tooth,automatic backlash adjust,electric closed coupling loading,measuring and analysis are solved. The complement software is developed,which is applied on YKZ9932 machine manufactured by Tianjin No. 1 Machine Tool Works. According to the test result,the gear transmission quality is reflected more systematically by using this new method.
- 3
- |
- 101
- |
- 1
发布时间：2022-10-20 - 摘要：Calculation of gear geometrical center is an important issue in measurement of large gears. On the basis of the establishment of discrete data model of involute gear,a method to calculate the geometrical center of large cylindrical gear is put forward,and the corresponding mathematical model is established. According to the calculated result of gear center,the gear tooth profile error is calculated,and compared with the calculated result with the standard gear geometrical center known. The simulation results show that after adding random noise of the amplitude of 0 318 μm on the grade 8 large gear,the calculated maximum error of gear geometrical center is less than or equal to 1 μm,while the gear tooth profile error between the theoretical value and calculated result is less than or equal to 10 μm,which suggests that the method can be effectively applied to the measurement of large cylindrical gears.关键词：Large cylindrical gear;Gear geometrical center;Tooth profile error
- 4
- |
- 124
- |
- 7
发布时间：2022-10-20 - 摘要：Aiming at the problem of chatter vibration during milling,a new method for solving multiple time delays system is presented to predict the stability in the process of milling cutter. A comparison with prior methods is conducted to verify the accuracy and efficiency of proposed approach for the stability prediction. By using the variable pitch cutter,the experiment of milling stability is carried out. According to the obtained predicted results,the multiple sets milling parameters are selected for the milling experiment,a consistency between the experimental data and theory study is studied. The experimental results show that the proposed method has a better predictive ability than the prior methods.关键词：Milling process;Variable pitch cutter;Milling stability
- 19
- |
- 99
- |
- 0
发布时间：2022-10-20 - 摘要：In order to solve the problem that the gear ring fracture of gear pump without unloading groove,by using 3D modeling software,a gear pump model is established. The maximum trapped oil pressure of gear pump with no unloading groove,symmetrical unloading groove and bias type unloading groove are obtained through the internal flow field simulation with FLUENT,then the volumetric efficiency of the three pumps are calculated,the fact that using gear pump with bias type unloading groove can be a good solution to solve the problem of trapped oil and improve volumetric efficiency of the pump is verified. By calculating,the bias position of unloading groove is designed,and the prototype testing verification is carried out. Through comparing,the simulation results are similar to the test results,and a reference for the design of the built- in gear pump is provided.关键词：Trapped oil pressure;Unloading groove;Flow field simulation;Prototype test
- 3
- |
- 63
- |
- 1
发布时间：2022-10-20 - 摘要：The helicopter tail reducer casing often fail in the process of development. A design improvement scheme of a helicopter tail reducer casing is proposed based on the test results of the applied full stress monitoring method. The full stress monitoring method contains static test,fatigue test,ground test and flight test. The static and fatigue weak position of the casing is exposed by the static test and fatigue test. Through the ground test and the flight test,it is found that the main cause of failure is the resonance between the casing and system. According to the above test results,the design improvement scheme is proposed. The main contents are as follows,changing the connecting strength of the reinforcing plate of the foot,reducing the thickness of the lightening hole in the ribbed plate area,increasing the thickness of the install foot,increasing the thickness of install side of the pinion roller bearing. The above local changes make the casing well matched with the system,meanwhile the stress is redistributed to improve its fatigue and static property. The dynamic stress level of the casing is reduced by 49%after improvement. The quality is significant increased by the ground test and the flight test.关键词：Tail reducer;Fault diagnosis;Stress monitoring;Static test;Fatigue test
- 5
- |
- 171
- |
- 0
发布时间：2022-10-20 - 摘要：In view of the problems of poor stability and low energy recovery of the traditional wind power device,a new type of wind power device is installed in the wind power device. The new type of wind power device layout scheme is set up,and the transmission layout scheme theoretical model is completed. Finally,in the end,the performance parameters of the wind power device are compared and analyzed through the test method.The research result shows that,after the installation of the improved CVT mechanism,the energy conversion efficiency of the wind power device is improved,and the connecting shaft torque magnitude and change range of the blade and gearbox is reduced. The improved CVT mechanism can improve the performance parameters of the wind power device,and the new layout scheme is feasible.关键词：CVT mechanism;Wind power device;Operating characteristic;Improved
- 4
- |
- 76
- |
- 0
发布时间：2022-10-20 - 摘要：Aiming at the problem of the gearbox bearing and gear shaft locking due to the startup sequence error in the high- speed gear units startup process. Through the technical analysis of the gearbox casing structure,the bearing structure and the lubricating oil stations,of a high- speed gear transmission device without pre- lubricated startup is designed and developed. And the safety and reliability of the device are proved by experiment and field application.关键词：No pre-lubricated;Sliding bearing;High speed gearbox;Prevent locking
- 4
- |
- 72
- |
- 0
发布时间：2022-10-20 - 摘要：<正>浙江东海减速机有限公司在扩大国内外高端市场方面取得很大成果,为了更好的满足高端市场需求,公司决定在真正实行国际标准的同时,提高生产效率、产品质量与技术创新,从而打造更高的品牌。现招聘高级齿轮减速机人才加盟:一、总工程师（技术总监）:1名,要求60岁以下,
- 3
- |
- 4
- |
- 0
发布时间：2022-10-20
- Technical support is provided by Beijing Founder electronics co., LTD 豫ICP备05013835号-5
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0