最新刊期
期 9 ， 2016
- 摘要：In order to study the dynamic performance of mechanism with lubricated clearance joint,an improved transition force model is established,accounts for not only squeeze-film effects,but also wedge-film effects,and is applicable to both long and short bearings. Then,taking the planar slider-crank mechanism with lubricated clearance joint as study object,through the analyzing and comparing of two working conditions of dry friction and lubrication,the rationality of the new model is verified. At the same time,through the simulation analysis of the different clearance values,the influence law of the clearance values on the dynamic performance of joint mechanism with lubrication clearance is studied. The study results show that,comparing with the working condition of dry friction,when considering the joint lubrication,the acceleration oscillation phenomenon of the mechanism is effectively suppressed,the dynamic performance is improved significantly. At the same time,with the increase of clearance size,the simulation results with lubrication appear deviation in the dead position of mechanism,and the more clearance size,the more obvious deviation,but the deviation is significantly less than that of dry contact clearance joint.关键词：Transitional force model;Clearance joint;Dynamic performance
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发布时间：2022-10-20 - 摘要：Through the analysis of the input and output characteristic of the full-coupled parallel mechanism,based on the theory of screws and the principle of individual driving,a method of structural synthesis of fully-decoupled three-translational and three-rotational（ 3R3T） parallel mechanism is proposed. Firstly,based on the requirement of the Jacobian matrix of full-coupled parallel mechanism is the nonzero diagonal matrix,by using the screw theory,both the positive and the inverse Jacobian matrix meeting the expected requirement are constructed. The actuation screws of branch chain drive pair acting on the moving platform is determined,and the motion screw system of corresponding branched chain is obtained,and the branch chain structure screw system configuration can be completed by this. Finally,according to the full-coupled parallel mechanism branch combination principle,the six branched chains is selected to link motion platform,a lot of fully-decoupled 3R3T parallel mechanisms are obtained. The output motion of the synthesized fully-decoupled parallel mechanism is provided by independent input of branched chain,and the positive and the inverse Jacobian matrix is always stay for diagonal matrix in the moving process,it is belong to fully-decoupled parallel mechanism. The structure of such mechanism is compacted,control is simple,and it also has good prospect.关键词：Individual drive;Fully-decoupled;Parallel mechanism;Type synthesis
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发布时间：2022-10-20 - 摘要：A novel large swing angle 1T2R parallel mechanism is proposed. First,the one-dimensional translational and two-dimensional rotation motion of this mechanism are analyzed based on the relation of motion and constraint in screw theory. The DOF of the mechanism is calculated,and the driving joints are chosen.Then,the inverse position solution equation of the mechanism is established by using analytical vector method and the geometric relation. At last,the position inverse solution is obtained by using MATLAB and the results simulation verification is carried out by using ADAMS,which verify that the correctness of the inverse position solution model and the realizability of the mechanism. This parallel mechanism with a large swing angle,can be used in hybrid machine of parallel modules to achieve large swing angle five-axis machining.关键词：Large swing angle;Parallel mechanism;Screw theory;Inverse position solution
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发布时间：2022-10-20 - 摘要：It often happens to tooth surface burn of hypoid gears installed on automobile drive axle during the gear lapping process,it will cause pitting,peeling and cutting. The discrimination method of lapping burn is presented by describing the features of burn location. The effect on gear durability caused by lapping burn is analyzed by studying the metallographic structure and the hardness variation and the effect is verified by rig test and road test. By establishing the mathematical model of the hypoid gear meshing point relative sliding and by calculating the relative sliding speed of each meshing point,it’s found that the burned area of tooth surface is the biggest relative sliding velocity. The reproducibility tests are down by several times of tests for lapping burn. It’s verified that the main factor in lapping burn is closely related to the lapping clearance control. Combining with the production practice experience,several methods to control the lapping burn are presented through revising operation standard,lapping clearance automatic monitoring,etc.关键词：Hypoid gear;Lapping;Burn control;Metallographic structure;Sliding speed
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发布时间：2022-10-20 - 摘要：In order to reflect the actual working conditions of the gear pair in the steering gear accurately,the mathematical model of the steering system is established,and the calculating formulas of the pitman arm moment and the steering nut displacement are given. A calculation method for the actual working condition of the gear pair in the circulating ball variable transmission ratio steering is proposed. Base on the vehicle steering portability test,the actual steering condition of the gear pair in a certain type of recirculating ball variable ratio is calculated,and the results is verified by simulation. The calculation result of the actual working condition of the variable transmission ratio gear is applied to the finite element analysis which can prove the feasibility of this method. The calculation method provides a loading basis for simulation and test which is closer to the reality.关键词：Steering gear pair;Actual working condition;Steering moment;Steering portability
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发布时间：2022-10-20 - 摘要：The residual vibration caused by flexible end-effector decreases the positioning accuracy,for transfer robots run with high speed and high acceleration,stop and start frequently. The active and passive control methods and the method of only considering motion curve smoothness are used to reduce vibration,but it has the problems such as time lag,control complexity and material cost limit. The motion of robot is simulated in dynamics method with ADAMS software,the influences of different motion curves on the motion positioning precision are compared and the parameters of S-curve are optimized. The optimized asymmetric motion curve is used to be motion curve to get robot move fast and smoothly. A motion planning method for transfer robot based on dynamics is proposed.关键词：Residual vibration;Adams;Simulation optimization;Motion planning
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发布时间：2022-10-20 - 摘要：A kind of auxiliary device for ankle rehabilitation based on rigid-flexible combination drive is introduced. The device has two degrees of freedom,while three-dimensional movement of the ankle can be achieved approximately. To analyze the rehabilitation effect of the device,the working spaces are studied. First,the device working conditions are given,and the constraints of the working space are analyzed. Then,the digital solution model for working space is established. Finally,the working spaces of the device are calculated by using Matlab. The analysis results can be used to optimize the device structure and determine its characteristic parameter. The process of this research can be as a reference for research of working spaces of mechanism with multiple movement mode.关键词：Ankle;Bionic;Auxiliary rehabilitation device;Workspace
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发布时间：2022-10-20 - 摘要：In order to make it convenient for computer automatic synthesize,the automatic type synthesis of planar kinematic chains with modified Assur-group adjacency matrix is proposed. First of all,aiming at the known amount of the components,the active ones and the Assur-group,the diagonal elements with the different combination modes is solved according to the Assur-group theory. Then the synthesis method and concrete process is summarized and the selected Assur-group adjacency matrix is defined. The kinematic chains are subdivided in terms of 3 conditions of pole number,active pole and Assur-group type,meanwhile the isomorphism is estimated. As a conclusion,the method has better regularity,high efficiency and is beneficial to eliminate the rigid chains and reduce the calculation workload of isomorphism identification. Especially,the method can be applied to the automatic type synthesis for the planar mechanism kinematic chains with multiple links and multiple degrees of freedom. In addition,the success is achieved in the application on the type synthesis for the planar closed kinematic chains with 12 links and 12-below-links. Finally,the type synthesis method is demonstrated with the example of kinematic chains with 6 links and single degree of freedom.关键词：Adjacency matrix;Assur-group;Kinematic chain;Type synthesis
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发布时间：2022-10-20 - 摘要：Due to the restriction of the motor parameter,the various constraints,such as angular velocity constraint and angular acceleration constraint should be considered when planning the trajectories of robot. By analyzing the constraints condition,a novel smooth and time optimal trajectory planning approach is proposed based on parametric modified trapezoidal. The time optimal trajectory planning problem which consider kinematics and dynamics constraints are transformed into a two-variable optimization problem with above trajectory planning approach,the time optimal trajectory is obtained by genetic algorithm. The effectiveness of the planning algorithm is verified by an experiment for a two degree hybrid manipulator. The results show that this planning algorithm can make full use of driving performances,and guarantee the continuity of the joint acceleration and torque.关键词：Constraint;Trajectory planning;Parametric modified trapezoidal;Time optimal
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发布时间：2022-10-20 - 摘要：The shore bridge reducer in the lifting mechanism often emit heat because of continuous operation and high load,if improper heat dissipation will greatly reduce its life. To achieve the real-time online condition assessment of the reduction gearbox of the hoisting mechanism,the influence parameters of heat dissipation should be known for determining the heat dissipation condition. In order to obtain the influence parameters,from the simplest condition,the stopped state in the work,by using the lumped heat capacity method,the reduction gearbox heat dissipation model is studied,the curve fitting theoretic support and the factors that can affect the heat dissipation are got. In order to verify the actual influence of these factors on the reducer heat dissipation,by using the control variable method,the actual temperature data is computed and analyzed. Then,by means of the function mapping software Origin,the temperature data of the reduction gearbox is fitted,a quadratic exponential function model is fitted and the function parameter is obtained. Combining with the influence factors,the regularity analysis is carried out,the foundation for future work of heat dissipation factor parametric is provided.关键词：Shore bridge;Hoisting mechanism reduction gearbox;Stopped state;Heat dissipation
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发布时间：2022-10-20 - 摘要：Because of the output response of the wind turbine transmission system caused by the gear fault is not stable,the dynamic performance of the transmission system in fault state is studied. The transmission system dynamics models under normal condition and gear fault condition are established respectively by considering the influence of time-vary stiffness and gear crack of helical gear,and the output responses of two systems are analyzed and compared. The results show that the output engaging force,torsional vibration displacement and torsional vibration velocity are relatively large and the irregular change trends are presented under the fault gear condition. The impact vibration is large at some simulation time points. The theoretical reference for the fault diagnosis and early fault prediction of the wind turbine transmission system is provided by the research results.关键词：Wind turbine;Gear transmission;Dynamics model;Response analysis
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发布时间：2022-10-20 - 摘要：Abstract Taking the controllable 5R planar parallel mechanisms（ PPM） as the study object,combining its engineering application,the kinematic model is established,and the full-information parameter modeling method of configuration transformation and movement characteristic analysis integration is proposed.Based on the bottom-up configuration design method,the model of bar-pair,kinematic sub-chain,main configuration are established. Through the variable drive layout,parameters configuration mode,the new configuration is transformed,the purpose of rapid reconstruction design of configuration and the simplified kinematics solution is achieved. The contrastive analysis of the output trajectory tracking before and after the drive layout configuration transformation is carried out,the result shows that the workspace is expanded. Through designing the experiment device,the effectiveness of solving the workspace by trajectory tracking method is verified.关键词：Planar parallel mechanism;Configuration reconfigurable;Full-information parameter model;Motion trajectory
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发布时间：2022-10-20 - 摘要：Aiming at the defects of single target for traditional parameter optimization on hybrid power for hybrid electric vehicle（ HEV）,the fuel economy,emission and riding comfort are as the multi-objectives optimization object,and taking the entire dynamic performance is as constraint condition,then the Non-dominated Sorting Genetic Algorithm-Ⅱ（ NSGA-Ⅱ） multi-objectives parameter optimization algorithm is proposed. The optimization results show that under the condition of meeting dynamic performance and good vehicle speed following effect,the average fuel economy increases by 5. 51%,the average emission increases by 14. 86%,the comfort performance meets with the riding requirements,and the maximum charging and discharging current reduces by half. Moreover,a series of global optimal solution of homogeneous distribution are obtained with the proposed algorithm,and the optimization results are satisfactory,which prove the proposed NSGA-Ⅱ multi-objectives parameter optimization algorithm is accurate and feasible.关键词：HEV;Hybrid power;Ultracapacitor;Parameter optimization;NSGA-Ⅱ algorithm
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发布时间：2022-10-20 - 摘要：According to the assembly sequence optimization problem of mechanical products,the assembly sequence is used as initial population,and the reference set is added to the genetic algorithm,and the intelligent iterative mechanism of the decentralized search algorithm is used to avoid the random nature of the search.The continuous optimization of the assembly,the optimal solution is obtained. Finally,the effectiveness and feasibility of the improved genetic algorithm is verified through the analysis of the three stage reducer.关键词：Assembly sequence;Correlation matrix;Scatter search algorithm;Genetic algorithm
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发布时间：2022-10-20 - 摘要：To study idle noise of diesel vehicle transmission,the equivalent mechanical model of the diesel vehicle transmission system is established. The engine flywheel wave function is obtained by test. The influence trend of characteristic of clutch torsion on the idle noise is studied and the characteristic of clutch torsion is optimized. The real vehicle test shows that idle noise problem is well solved through the optimal design.关键词：Diesel vehicle transmission;Idle noise;Characteristic of clutch torsion;Optimization design
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发布时间：2022-10-20 - 摘要：The physical construction and transmission principle of ammunition displacement stopper in a certain automatic howitzer are analyzed,and the similar device applied to mortar automatic magazine is designed based on features of mortar ammunition and chain shell pushing mechanism. The key point of lock-unlock problem is solved by creatively using the motion of shell pushing and the principles of cam drive. The rotation angles and contact forces curve of key parts are obtained from simulation analysis in ADAMS,the results show that the device is feasible and reliable.关键词：Cam drive;Mortar;Automatic magazine;Displacement stopper
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发布时间：2022-10-20 - 摘要：A bionic device for the ankle,which has shaft non-perpendicular is designed in according to the structure characteristics of human physiological ankle. The device is consist of three degrees of freedoms that the rotating joint of lower leg,ankle joint and subtalar joint. To reduce the quality of ankle,the motors driving the ankle and the subtalar joint are installed on the thigh and transmission through cables,which cross the knee,fixed on the sheave to limit the rotation angle of each joint. The D-H coordinate method is used in coordinate system selection. Through simulation,the motion attitude space of the mechanism is analyzed and calculated,and compared with the related attitude parameters of human foot. It shows that this mechanism can achieve motion features that similar to human physiological ankle joint. This mechanism can be used in the field of humanoid robot,and can also be a reference for the research of the movement characteristic of the human ankle joint.关键词：Ankle joint;Mechanism design;Bionic
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发布时间：2022-10-20 - 摘要：The self-centering center rest is used in machining slender shaft parts such as lead screw,screw rotor and crankshaft. The machining precision of parts is affected directly by the clamping precision of self-centering center rest. The parametric mechanism model of self-centering center rest is established based on the mechanisms and theoretical mechanics. The load-carrying capability of self-centering rest is calculated by the long lead screw grinding for example. Combined with the parametric design and virtual prototype technology,then the motion simulation of the self-centering rest is analyzed. The simulation data and the theoretical calculation value are good consistency. Thus,a new method of structure design and topology optimization of self-centering center rest is provided.
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发布时间：2022-10-20 - 摘要：A hexapod robot with fewer actuators,good obstacle capability and good stability is designed.The whole structure of the hexapod robot with fewer actuators and the gait of walking are analyzed. On this basis,the equation of foot trajectory is established. The requirements of foot movement and obstacle crossing are obtained. The mathematical model of the foot trajectory of the hexapod robot with fewer actuators is established.The trajectory optimization model of foot trajectory for the stability of hexapod robot movement is established considering five types of constraints-the rod length,transmission performance,geometric structure,obstacle and boundary conditions. By using MATLAB optimization toolbox constraint fmincon function,the parameters effecting the foot trajectory of the hexapod robot with fewer actuators are optimized. The dimensions of leg mechanism of the hexapod robot that meet the kinematic characteristics requirements are obtained. The rationality of the leg mechanism is proved by the analysis of the optimized foot trajectory. All of these provide the foundation for the following research and development of the hexapod robot.关键词：Hexapod robot;Leg mechanism;Foot trajectory;Optimization design
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发布时间：2022-10-20 - 摘要：Based on the activity price method and the space engagement theory,the forming process of the ZC. 1 grinding wheel and the mathematical model of the worm pair are researched. Based on the numerical analysis method and finite element method,the 3D solid model of worm pair is completed by Solid Works and MATLAB,and the finite element model is established in ANSYS. Through the data processing of finite element calculation results,the load distribution among gear teeth,the distribution of the contact stress along the direction of the worm gear tooth and the comparison between the results of the finite element method and the empirical strength formula are analyzed. Considering the installation error of worm gears contact impact force and contact line and that priority should be given to reduce the shaft angle error. The research conclusions provide the theoretical basis for the three-dimensional modeling and strength analysis of ZC1 worm drive.关键词：Worm drive;Finite element method;Strength analysis;3D Modeling
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发布时间：2022-10-20 - 摘要：A climbing mechanism based on the gear rack transmission is proposed. From the actual motion of the system and the device flip climbing movement conditions,the mathematical model is built,on the premise of guarantee stability margin,the optimal climbing posture is got. The key parts are analyzed by using the finite element analysis method. At the same time,from the standpoint of improving the degree of automation of device,the flip climbing progress control flow chart is established,the foundation for control system design is provided.关键词：Gear rack transmission;Climbing mechanism;Mathematical model;Control flow
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发布时间：2022-10-20 - 摘要：As a new type of specially defined pluralized vector model,the ternary number has the naturally intuitive geometric significance and it is especially helps to the three-dimensional modeling for a spatial problem. Based on the original concept of a ternary number,starts from the definition of the rotated projection product of a ternary number,the meaning of the ternary number is extended at first,the differential features of a ternary complex variable is analyzed,and then the conclusion on the differential properties of a ternary complex variable is obtained. The differential operation to a ternary complex variable can be transformed as the operating of the rotated projection product of a ternary number. As this result,it provides a new path for the analytic solution of the spatial motion analysis of the some mechanism. The checkout of the endpoint velocity and acceleration for a three-joint simple robot is carried out by this means. Both their size and direction are obtained in the only calculation process at same time. Finally,the analysis of the position is carried out for the 3-RPS type of the 3-DOF parallel robot. From another point of view,above mentioned facts show and verify that it is possible and feasible for the analytic solution of the motion analysis of the three-dimensional spatial mechanism by means of the modeling tool of a ternary number.关键词：Ternary number;Rotated projection product;Articulated robot;Spatial motion analysis;Parallel robot
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发布时间：2022-10-20 - 摘要：In theoretically,all teeth of spline pair transmitted the same load. In practice,due to manufacturing and mounting errors,not all teeth transmit the same load and as a result,the overloading condition may occur. Based on finite element method,the distribution of contact pressure and load among teeth of involute spline pair with the conditions of angular misalignment,parallel misalignment and those two combined misalignment are investigated. The results have certain guiding significance and engineering application value in guiding involute spline pair manufacturing and assembly.关键词：Finite element method（FEM）;Spline pair;Misalignment;Load distribution
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发布时间：2022-10-20 - 摘要：The fluid-solid coupled heat transfer analysis focus on computational fluid dynamics（ CFD）and solid heat transfer finite elements（ FEA）. The partition solving and boundary coupling are used to study a fluid-solid coupled heat transfer system which is formed by every part of brake. By this method,the outer and being difficult to identify borders of a single part heat transfer can be transformed into inner borders,it can only define the external borders for calculating,which is more practical and easier to calculate. Comparison between simulation and measurement data shows that the simulation data are in good agreement with experimental results. So,taking the coupling method to simulate brakes thermal conduction and heat convection is feasible.关键词：Bake;Fluid solid coupled heat transfer;Boundary coupling;Multi physical field
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发布时间：2022-10-20 - 摘要：The torque transmission performance of flight simulator with double 3-RRS over-redundant actuation spherical parallel manipulator is analyzed. The flight simulator has 3 rotational degrees of freedom,6 actuators,3 redundant actuators are included in 6 actuators. Two totally same spherical parallel manipulators consist of the flight simulator. Because of only one fixed coordinate frame is established,it has one fixed base in general and one moving platform. The whole moving platform is served as the flight simulator capsule. The directional cosines of the branch are determined by anti-symmetric coordinates frame,and on this basis,the Jacobian matrix of the over-redundant actuation spherical parallel manipulator is given. The torque transmission performance index of the double and single 3-RRS over-redundant actuation spherical parallel manipulator are analyzed and its atlas of torque transmission performance are given out,and according to the 3D atlas,the analysis conclusion is given.关键词：Spherical parallel manipulator;Flight simulator;Jacobian matrix;Torque transmission performance
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发布时间：2022-10-20 - 摘要：In order to improve the stability and reliability of the integral centrifugal compressor high-speed gear shaft rotor,the dynamics model of the high-speed shaft rotor is established by the professional analysis software. The influence factors of the impeller and the bearings on the dynamics performance of the rotor is analyzed. Through the measurements of increasing the rotational inertia of the impeller,decreasing the mass of the impeller and the distance of the impeller to the bearing,increasing the bearing span of the gear box,bearing shaft diameter and the bearing stiffness,the first order critical speed of the rotor can be improved. Through the measurements of increasing the rotational inertia of the impeller,decreasing the mass of the impeller and the distance of the impeller to the bearing,decreasing the bearing span of the gearbox and the bearing shaft diameter,increasing the bearing stiffness,the second order critical speed of the rotor can be improved. On the contrary,the first and second order critical speed can be reduced.关键词：Rotor dynamics analysis;Critical;Speed Integral centrifugal compressor
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发布时间：2022-10-20 - 摘要：The impact load is the main reason that reduces the useful life of the gear transmission system.At first,the 3D virtual prototype of controlled start transmission（ CST） gearbox transmission part is created by Pro / E and then imported into ADAMS. The dynamics simulation of the gear system under impact load is carried out. The meshing force and various transmission angular velocities and frequency spectrum curve are solved,and the variation situation of the mesh force and its frequency-domain characteristic under the impact load or no impact load are compared,the result shows that the gear mesh frequency vibration energy increases obviously because of the impact load. The simulation results is closed to the theoretical analysis result. This study could provide data to be used for the subsequent calculation of gear fatigue life with considering the impact load.关键词：Gear transmission;Virtual prototype;Dynamics analysis;Impact load
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发布时间：2022-10-20 - 摘要：For signal speed ratio electric vehicle is prone to slide backward under ramp start condition,a ramp start control strategy based on road gradient identification is proposed. The kinematics linear regression model of the signal speed ratio electric vehicle under ramp start condition is constructed,then a road gradient identifier based on multi-innovation forgetting gradient algorithm is designed,the ramp anti-slide control strategy is formulated according with driver intention. The system simulation model is built in Matlab / simulink,the results indicates that the ramp start control method could well indentify road gradient,the ramp slide backward phenomenon is effectively prevented and the vehicle start characteristic is improved.关键词：Electric vehicle;Gradient identification;Ramp start;Control
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发布时间：2022-10-20 - 摘要：In order to study the transmission performance of the COMI and CIMO type coupler with the same structure parameters,the equivalent magnetic circuit method is used to analyze and derive the torque formula of the coupler,and the final torque expression is acquired by combining the torque formula and three dimensional correction coefficient. Also,the efficiency formula of magnetic coupler is derived. Then,the finite element simulations is used to analyze the transmission performance of the two kinds of couplers when they are under the same input speeds and slips ratio. The results indicate that COMI type coupler has the same transmission efficiency with the CIMO type coupler,but can get bigger torque when they have the same geometrical parameters,which means COMI type coupler has better transmission performance.关键词：Magnetic coupler;Equivalent magnetic circuit method;Torque formula;Transmission performance
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发布时间：2022-10-20 - 摘要：Aiming at the structure features of the trapezoidal tooth synchronous belt and belt pulley,the 3D solid models of synchronous belt and belt pulley are established by using UG,the mesh generation is carried out by using the Hyper Mesh and the models are imported into the multi-body dynamics RecurDyn software,the overall movement dynamic performance analysis of the coupled system dynamics of the trapezoidal tooth synchronous belt is carried out. The influence law of initial tension,spindle speed and drive load changes on the stress of the belt tooth is studied,a new digital simulation analysis method for the synchronous belt design,mechanical characteristic analysis is provided.关键词：Trapezoidal tooth synchronous belt;MFBD;System dynamics;Recurdyn
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发布时间：2022-10-20 - 摘要：A finite element analysis model of the ZA synchronous belt drive system is established. Through the finite element method,the natural frequency of the automobile synchronous belt and its dynamic response under the action of meshing impact excitation are analyzed. And based on the dynamic response results,the acoustic boundary element analysis model of the transmission system of the automobile synchronous belt is established by the direct boundary element method,the influence law of meshing excitation frequency on the synchronous belt surface sound pressure and field radiated noise is analyzed. The noise test of the synchronous belt drive system is carried out by using two wheel load test method. Comparison of the radiated noise and the numerical simulation results,the accuracy and feasibility of the simulation method is verified.关键词：Automobile synchronous belt;Dynamic response;Radiation noise;Direct boundary element method
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发布时间：2022-10-20 - 摘要：Based on the traditional cycloidal pinwheel reducer,the improved new type of cycloidal needle roller vibration attenuation reducer has added a new structure called flexible pad,which would reduce and prevent the high frequency fluctuations of a motor and the high frequency fluctuations produced in the transmission process,the whole performance and life of the equipment can be improved. The corresponding comparison and choice of the material parameters for the flexible pad is carried out through accurately modeling and finite element modal analysis. The results show that the maximum deformation of all the comparative reducers are in the normal range,and with the increase of the materials hardness,the maximum deformation order has gradually increasing trend. The new type of cycloidal needle roller vibration attenuation reducer which added the flexible pad,will be better able to avoid resonance.关键词：New type of cycloidal needle roller vibration attenuation reducer;Flexible pad;Accurately modeling;Modal analysis;Resonance
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发布时间：2022-10-20 - 摘要：The continuously variable transmission can significantly improve the dynamic performance of automotive,which is the development direction of automobile transmission. The metal belt is the main transmission component of automotive continuously variable transmission,the four layers metal band analysis model is established,and the force and change of velocity of each layer of metal belt in different working conditions are analyzed. The results show that when the metal belt between the friction rate is small,the major tension used for transmission torque is in the first layer of metal band,with the friction rate between each layer of metal band belt increase,the four layers of metal band relative slip decreases and the velocity difference becomes small.The friction between metal bands belt can be effective delivery of torsional moment,the final metal belt tension began to evenly distribute to the four layers of metal belt. With the metal bands belt outward,the operating speed of band gradually decreases on the driver pulley,through the mechanical analysis of automotive continuously variable transmission,which provides an important reference for the design and dynamic characteristics study.关键词：Automotive continuously variable transmission;Multi-metal belt;Mechanics model;Tension
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发布时间：2022-10-20 - 摘要：On the basis of considering the influence of the interface between the bearing outer ring and bearing pedestal,the study and analysis on the relations among the different materials bearing pedestal and rolling element bearing inner ring,outer ring and the vibration characteristic of bearing pedestal are carried out.The analysis results show that the influence of the material characteristic on vibration response of the bearing inner ring,outer ring and bearing pedestal is large,the greater the difference of the elasticity modulus between the bearing and the bearing outer ring,the greater the vibration amplitude of bearing inner ring,outer ring and bearing pedestal. The influence of bearing pedestal material characteristic on the bearing outer ring and bearing pedestal vibration characteristic is larger than the bearing inner ring. The vibration amplitude of the bearing system can be effectively controlled by using appropriate bearing pedestal material.关键词：Rolling element bearing;Bearing pedestal;Interface;Vibration characteristic
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发布时间：2022-10-20 - 摘要：Aiming at the high-performance magnetic gear with 7 pole pairs of permanent magnet inner rotor and 15 pole pairs of permanent magnet outer rotor,in order to study the working principle and transmission performance,the three different running manners are discussed,their gear ratios relation are derived,and the relationship among efficiencies,torques and gear ratios are also derived. When the speeds is lower,the efficiency is almost equal to 1,thus the out torque is equal to the input torque times its gear ratio. Also,the three different running manners under lower speeds are dynamically simulated by using the finite element analysis software,and the influence of different loads on torques is obtained. Then,the input torque and output torque are measured under different loads by transmission experiment platform respectively. The results show that the input torque increases linearly with the increase of the output torque,and the ratio of output and input torque is equal to the gear ratio. All these can be used to estimate the dynamic torque when the transmission ratio is given.关键词：High-performance magnetic gear;Transmission performance;Dynamic simulation analysis;Prototype test
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发布时间：2022-10-20 - 摘要：Aiming at the problem of numerical synthesis on conjugate curve processed by pre-grinding bob,a new method of arbitrarily complex multiple plane curves numerical synthesis to a curve is given. In this method,the curve is dispersed into points and establishing a matrix,after amplification,the discrete data point is put in the matrix to compare the size,and achieve synthesis. Applying this method,the synthesis validation is carried out through the tooth root conjugate curve processed by C type pre-grinding hob.关键词：Pre-grinding hob;Conjugate curve;Numerical synthesis
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发布时间：2022-10-20 - 摘要：In view of the operating principles and structural characteristics of hole-pin type few teeth difference planet gear speed increaser,the contacting conditions of pin and pin hole during the operating process for various structure parameters are analyzed. Based on the geometrical relationship during operating process,the pressure angle analytic formula between pin and pin hole is derived. The curve of pressure angle is calculated and drawn by selecting different design parameters to find the relationships of pressure angle with rotor eccentricity,the turning radius of pin hole,diameter of pin and pin hole. The calculation methods and analytical results could guide the structure design of hole-pin type few teeth difference planet-gear speed increaser,optimization of the system force transmission characteristic.关键词：Hole-pin type;Few teeth difference;Planet-gear;Pressure angle
- 3
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- 60
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- 0
发布时间：2022-10-20 - 摘要：Through studying a crossing obstacle model for the ladder shaped obstacle an optimal size design algorithm based on this model is designed. By the trial value method,the design requirement of calculating the optimal mechanical foot size automatically and making the crossing obstacle efficiency of the mechanism achieve the highest is realized. by value method. Then,the feasibility of this algorithm is verified through the experimental,by using MATLAB,the graphical user interface is designed which can output the crossing obstacle time and the optimal mechanical foot size after input the parameters of obstacle and motor. The design efficiency of this crossing obstacle model is improved,and an optimization method for the model parameter design is provided.关键词：Ladder shaped obstacle;Leg-wheel robot;Optimal algorithm;Matlab/GUI
- 3
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- 164
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- 0
发布时间：2022-10-20 - 摘要：Based on the involute cylindrical gear as research object,the initial premise of the existence of cracks on the tooth root,the root of the fatigue crack growth characteristics and life are studied. The dynamics calculation of the gears meshing is equivalent to multiple engagement position static analysis,the stress intensity factors at different positions are obtained. According to the linear elastic fracture mechanics, the linear equivalent of crack growth is carried out,by using K criterion to analyze whether the crack extend. According to the Paris criterion to determine the amount of crack growth,using the maximum circumferential stress criterion to determine the crack growth angle,the stress intensity factor,crack growth path and fatigue life of the calculation cycle are obtained. By using high frequency test bench,the fatigue tests are carried out on the gear,the gear fatigue the expansion path is got,and comparing with the results of finite element calculation results.Finally,the influence of different initial crack size,position and load on fatigue crack growth and fatigue life is analyzed.关键词：Gear;Fatigue crack growth;Fatigue life;FEM
- 6
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- 219
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- 2
发布时间：2022-10-20 - 摘要：The working principle of an internal gripping device of the manipulator based on worm and worm gear and crank connecting rod drive is introduced. Its mechanical properties and calculation formula are also given out. After the device being driven by gear motor,output torque rotates the worm first and transmits the driving force to the worm. Then the worm rotates the upper and the lower worm gears which are meshed with it separately and the worm gears sway the upper and the lower crank connecting rods articulated in worm gears.Lastly,two times amplification of the force by the force-amplifier of the upper and the lower crank connecting rods is realized. The gripper can stick close to the object or the inside surface of workpiece accurately,then grip the object and hold it tightly in balance. The device has the characteristic of compact structure,easy operation,time-saving and less effort,well flexibility and high greenization.关键词：Manipulator;Worm and worm gear;Crank connecting rod;Gripping device;Gear motor
- 9
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- 214
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- 1
发布时间：2022-10-20 - 摘要：The difference of bevel gear strength rating methods between ISO standard and AGMA standard is analyzed and compared. The meaning of correction factors and differences between the two standards are analyzed through classifications and examples,and the gear parameters effects on gear rating results are also analyzed. The study indicates that it is the different values of parameters and correction factors that cause the differences in gear rating results of the two standards,and the load,geometry parameters,material property and surface condition have the most significant effects. The AGMA standard tends to be conservative in the calculation of contact strength,whereas ISO standard tends to be conservative in the calculation of bending strength.关键词：ISO standard;AGMA standard;Bevel gear;Gear strength;Comparison
- 8
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- 151
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- 2
发布时间：2022-10-20
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