最新刊期
期 9 ， 2018
- 摘要：Based on the generalized finite element method and the substructure method,a dynamics model of the double gearbox transmission system coupled by the diaphragm coupling is established. The dynamic meshing forces and the dynamic bearing forces are calculated through the Fourier method,which are then compared with the results without considering the coupled effects. The result shows that the coupled effects on meshing pairs are small,while effects on bearings are more significant especially on those close to the coupling,and when considering the coupled effects,the dynamic meshing force and dynamic bearing forces emerge other frequencies,but the amplitudes of them are small.关键词：Generalized finite element;Substructure method;Coupled vibration;Dynamic characteristic
- 4
- |
- 211
- |
- 2
发布时间：2022-10-20 - 摘要：Based on energy method and Hertz contact theory,a calculation model of mesh stiffness of the cycloid-pin gear pair is proposed with considering the bending,shearing and compression deformation of the cycloid gear tooth as well as the bending,shearing deformation of the pin. With calculating the torsion deformation of cycloid gear under load condition,the calculation formula of mesh stiffness and torsional stiffness of single tooth pair at the contact point are given. Based on the proposed calculation model,the influence of tooth profile parameters on the meshing stiffness and torsional stiffness are analyzed,including the eccentricity,pin position radius,pin radius and tooth number. The calculation method can be used for the analysis of the force and dynamics characteristic of the cycloid-pin gear drive,it has a certain reference value.关键词：Cycloid-pin gear drive;Meshing stiffness;Energy method
- 3
- |
- 208
- |
- 3
发布时间：2022-10-20 - 摘要：In harmonic gear drive,backlash has a significant effect on transmission performance. Based on the exact conjugate method of harmonic drive,the changes of conjugate zone,circular spline conjugate tooth profile and backlash of harmonic drive with the variation of flexspline tooth profile parameters are studied. The results show that flexspline profile parameters play a decisive role in conjugate section,circular spline conjugate tooth profile and backlash. Reducing the circular arc radius of convex tooth profile is helpful to increase the meshing conjugate zone,but not conducive to reducing the backlash. The circular arc radius of concave tooth profile has no obvious effect on the conjugate zone,but has a significant effect on the backlash. Reducing the common tangent angle is helps to increase the conjugate zone,reduce the backlash and improve the backlash distribution. The circular arc radius of convex and concave tooth profile of flexspline have obvious influence on the circular spline tooth profile parameters,but the common tangent angle have little effect on it. A reasonable choice of flexspline tooth profile parameters may bring a bigger conjugate zone and more well-distributed backlash,the carrying capacity and transmission performance can then be improved.关键词：Harmonic drive;Double circular arc tooth profile;Tooth profile parameter;Conjugate tooth profile;Backlash
- 3
- |
- 176
- |
- 4
发布时间：2022-10-20 - 摘要：The changing of meshing stiffness will lead to vibration and reduce the stability of the gear drive. By using Abaqus general analysis step and implicit dynamic analysis step,the meshing process of elastic and rigid gear pair of shear cutting department are calculated respectively. In MATLAB,the three-coordinate plot is applied to analyze the stress characteristics of gear pair in the whole meshing process. The Mises stress of tooth profile at different meshing positions and moments are calculated. The maximum contact press,the maximum Mises stress and their positions during meshing are calculated. The results show that the varying meshing stiffness caused the angular displacement deviation fluctuation during the static meshing of gear pair,in addition,the fluctuation of driven gear angular velocity lead to larger fluctuation of angular displacement deviation during dynamic meshing of gear pair. The change of load and the change of meshing stiffness caused the fluctuation of angular velocity deviation of driven gear. The methods and references for gear design and research of shear cutting department are provided by this study.关键词：Finite element;Gear pair;Implicit dynamics;Stress;Fluctuation
- 3
- |
- 162
- |
- 2
发布时间：2022-10-20 - 摘要：Taking an electric vehicle equipped with EM-CVT as the research objects,the research of weak drivability and optimization of control strategy are carried out under the impact of EM-CVT in braking energy recovery condition,which on the basis of confirming vehicle transmission scheme,vehicle parameters and control strategy. By analyzing longitudinal dynamics in the braking process,it turns out that CVT ratio and the changing rate of speed ratio are the influence factor to drivability under the impact of EM-CVT in baking energy recovery condition. Firstly,the weak drivability and the control strategy of original vehicle are explained,the relationship with drivability influence factor is analyzed,and speed adjustment strategy of the EM-CVT is optimized. The result shows that,the intervention process of regenerative brake is slow down,and the speed ratio in regeneration baking process and speeding up process is well matched,without large fluctuations,and the objective of optimized vehicle drivability is achieved.关键词：Electric mechanical continuously variable transmission（EM-CVT）;Electric vehicle;Drivability;Speed adjustment strategy
- 4
- |
- 186
- |
- 2
发布时间：2022-10-20 - 摘要：To analyze the sliding characteristic of the traction drive reducer for the automotive in-wheel motor,the working mechanism is researched. Then,a mathematical model and an analysis method are proposed to accurately calculate the sliding characteristics combined with the elastohydrodynamic lubrication（ EHL） theory. Moreover,the relationships between the sliding rate and the transmission power are revealed,and the influences of the pressing force and the friction pair length on the sliding characteristics are discussed. The results show that,at a constant sliding rate,the increase in the pressing force can promote the viscosity and ultimate shear stress of the traction oils,improving the input and output powers; at a constant pressing force,with the increase in the sliding rate,the input and output powers first increase,and finally the input power tends to be stable while the output power decreases after reaching a peak; at a constant pressing force and a constant sliding rate,with the decrease in the inner or outer friction pair length,the input and output powers first increase and finally tend to a stable value respectively.关键词：Automotive in-wheel motor;Traction drive reducer;Sliding characteristic;Elastohydrody namic lubrication;Transmission power
- 4
- |
- 88
- |
- 1
发布时间：2022-10-20 - 摘要：The load distribution considering clearance and deflection of the cross universal joint bearings of a JIEFANG truck is calculated by using MATLAB programming and ANSYS numerical analysis method. The load distribution calculation results are used as the input conditions for stress analysis. The contact stress analysis is carried out on the maximum loaded needle roller. Based on the obtained stress extremum,the life modified model of the cross universal joint bearings is established. The analysis results indicate that compared with traditional life calculation method,the modified bearing life calculation method takes into account the effect of clearance and deflection on the life of cross universal joint bearings. The prediction accuracy of the bearing life is significantly improved. The experimental verification results are in good agreement with the analysis conclusion.关键词：Clearance;Deflection;Cross universal joint bearing;Life modified
- 4
- |
- 80
- |
- 0
发布时间：2022-10-20 - 摘要：A new type of output mechanism with shaking block chute type small tooth number difference is proposed,and the motion analysis of the transmission pin and the output shaft is carried out. Then through the software establishment three-dimensional model,the movement simulation analysis of the reducer is carried out.The characteristics of the output movement is studied. By changing the distance between the drive pin and the outer gear center and other parameters,the smoothness of the output movement is improved.关键词：Shaking block chute type;Small tooth number difference;Output mechanism;Movement analysis
- 4
- |
- 45
- |
- 0
发布时间：2022-10-20 - 摘要：The roller is a crucial component with regard to pipe belt conveyor system,which supports belts and cargos,reducing the number of roller can effectively reduce the production cost. Aiming at the pipe belt conveyor roller pitch design and layout issues,taking the typical positive six sides shaped roller group structure as an example,the mechanical analysis and deduction are conducted by considering the interaction relation between the conveyor belt,material and roller structure. The four main factors that affect the spacing between rollers are expounded. Moreover,the mathematical expression of reasonable arrangement of roller spacing is derived,and the correctness of the expression is verified by an engineering example. The results can take the reference for accurate quantitative analysis and optimal design and pipe belt conveyor.关键词：Pipe belt conveyor;Wedge resistance;Roller spacing
- 4
- |
- 109
- |
- 7
发布时间：2022-10-20 - 摘要：The installation error and axial deformation of gear exist in the actual working conditions,result in partial load and affect contact state and fatigue performance of gear. The research of the fatigue performance of herringbone gears under variable load when considering the effect of installation error and axial deformation is one of the difficult problems in the design of herringbone gear. A method for analyzing the fatigue performance of herringbone gears under the variable load and actual working conditions is proposed. The modeling method of finite element contact analysis model considering the influence of installation error and axial deformation is proposed. The calculation of the partial load of herringbone gear under the actual load condition based on the finite element contact analysis model. The safety factor of contact strength of the gear is calculated based on the stress results of loading contact analysis and load spectrum. The work of this study provides a useful reference method for the design and analysis of high performance herringbone gear.关键词：Herringbone gear;Installation error;Axial deformation;Variable load;Fatigue performance
- 3
- |
- 131
- |
- 1
发布时间：2022-10-20 - 摘要：Aiming at the complicated structure,difficult position analysis,strong coupling and hard to control of tradition parallel mechanism,a new type of low coupling 2 T2 R parallel mechanism is designed. First of all,the new 2 T2 R mechanism is analyzed for the kinematics based on position and orientation characteristics（ POC） set theory. Then,in order to minimize the kinematics equation dimensions,using a single open chain theory to break down the mechanism and build the location analysis model. Finally,analysis and verification with specific examples is conducted. The results show that the mechanism is four degrees of freedom,the mobile platform can achieve two translation and two rotation. The structure is low degree of coupling,having motion input-output partially of the decoupling makes the position equation of this mechanism simple,and the equation can be solved analytically.关键词：2T2R parallel mechanism;Partially decoupled;Position and orientation characteristic set;Location analysis
- 4
- |
- 144
- |
- 1
发布时间：2022-10-20 - 摘要：The third stage helical gear of wind turbine gearbox is high-speed heavy-duty gear and it has high maintenance cost and high requirement for reliability. The fatigue pitting is one of the most common failures,which will make the reliability decline. The finite element model of helical gear with pitting corrosion is established. The stress spectrum is calculated and the reliability of helical gears with different pitting diameters and numbers are obtained under the effect of the wind field measured torque spectrum. The results show that the reliability of gear declines with the increase of pitting diameter,with the increasing number of pitting corrosion,the reliability is remarkably declining.关键词：Wind turbine gearbox;Stress intensity;Fatigue pitting;First-order second-moment method;Gaussian mixture model;Reliability
- 4
- |
- 222
- |
- 2
发布时间：2022-10-20 - 摘要：A dynamic shift schedule is designed for the prototype of hydraulic power shift automatic transmission. The steady-state schedule cannot adapt to dynamic condition,aiming at the problems including wrong shift caused by sudden change of throttle,a four-parameter fuzzy control method is designed to modify based on throttle opening,throttle change rate,acceleration and speed. Based on the recursive least square method,a road ramp prediction and shift control schedule is designed in order to eliminate the cyclic shift. A model of vehicle is built,the result of simulation proved that the fuzzy control method successfully improve the acceleration performance and eliminate wrong shift under fast fuel filling. The ramp shifting control method can effectively identify the slope and eliminate the cyclic shift.关键词：Automatic transmission;Shift schedule;Fuzzy control;Recursive least square method;Vehicle simulation
- 3
- |
- 152
- |
- 2
发布时间：2022-10-20 - 摘要：Based on the computational fluid dynamics theory,the mathematical model of the fluid domain inside the hydro-viscous speed regulating clutch is established,and the multi-phase flow field in the radial groove friction pair is solved numerically by the CFD software. The influence of the groove number and speed on the oil film pressure distribution under cavitation effect is studied,and the change of load-carrying capacity along with particle mass fraction and diameter is analyzed by the method of phase coupling. The result indicates that the pressure increases with the increase of the speed,and shows the periodicity and inhomogeneity,in which the pressure decreases gradually along the direction of the radius increase and tends to be consistent,and the groove number has little effect on the maximum pressure. In the transitional region,the pressure fluctuates obviously,and the negative pressure appears at the edge of the groove,the most significant cavitation effect occurs in the inner wall of the groove opposite to the direction of rotation. With the increase of the particles mass fraction,the load-carrying capacity increases,and compared with the minimum film thickness,the particle diameter is too large or too small,its influence on load-carrying capacity is not significant,when the particle size exceeds a certain value,the load-carrying capacity will be significantly improved.关键词：Hydro-viscous speed regulating clutch;Cavitation;Particle;Load-carrying capacity
- 3
- |
- 55
- |
- 1
发布时间：2022-10-20 - 摘要：Aiming at the situation that the robot is multi-driven and has complex kinematical characteristics and control system,a waist structure of robot with dodge function is designed,which has the characteristics of single-drive,multi-degree of freedom,simple structure,accurate and easy motion classification. The kinematical principle of the structure and the selection of the relevant initial parameters are introduced and the coordinate transformation matrix of the upper body under different conditions is obtained by Denavit-Hartenberg（ D-H） method. The positive and inverse solutions of the robot are obtained. Finally,the three-dimensional model of the structure is built,the model is simplified and imported into ADAMS software for kinematics simulation analysis and the results are verified by experiments.关键词：Dodging function;Robot waist structure;Single drive;Coordinate transformation;Kinematics analysis;Adams
- 3
- |
- 176
- |
- 1
发布时间：2022-10-20 - 摘要：The rear leg mechanism of climbing wheelchair is the typical planar 2 degrees of freedom fivebar linkages,in order to improve the motion performance of the wheelchair,based on the kinematic analysis and the stress analysis on the key point of the rear leg,taking the length of two side links and one linkage of the five bar linkage as the design variable,the mean of the parallel mechanism Jacobian condition number as the objective function,the constraint conditions are given,and the nonlinear genetic algorithm are used to the optimization design of wheelchair rear leg mechanism. After that,the motion track before and after the optimization of five bar mechanism and the stress of the key point are simulated in the MATLAB. Through the comparison shows that,the optimal Jacobian condition number decreases obviously,the active space of five bar mechanism is more compact and the singular configuration of the mechanism is effectively avoided. The position and posture of the rear leg turn more flexible. The force at the key points of the rear leg mechanism is obviously reduced,the noise in the working process is effectively reduced and the wheelchair run more smoothly. In short,through the optimal design,the performance of the wheelchair is significantly improved.关键词：Climbing wheelchair;Five bar mechanism;Multiobjective optimization;Genetic algorithm;Matlab
- 7
- |
- 308
- |
- 3
发布时间：2022-10-20 - 摘要：In order to study the dynamic contact performance of cylindrical gear with variational hyperbola and circular-arc-tooth-trace,based on the tooth surface equation obtained from the machining principle of rotary cutter,a precise 3 D model of gear can be established by using MATLAB and UG. The distribution of contact stress in the gear tooth surface during the meshing process is obtained by ANSYS LS-DYNA. By studying the dynamic contact performance of cylindrical gear with variational hyperbola and circular-arc-tooth-trace under different radius of the tooth line,the influence of the radius of the tooth line on the meshing performance of the gear is obtained. By studying the dynamic contact characteristics of cylindrical gear with variational hyperbola and circular-arc-tooth-trace under different pressure angles,the influence of pressure angle on the dynamic meshing characteristics of the gear is obtained. By studying the dynamic contact stress of the gear under different loads,the influence of load on the dynamic meshing characteristics of the gear is obtained. The analysis results provide reference for the design and engineering application of cylindrical gear with variational hyperbola and circular-arc-tooth-trace.关键词：Cylindrical gear with variational hyperbola and circular-arc-tooth-trace;Dynamic contact;Tooth line radius;Pressure angle;Load
- 3
- |
- 185
- |
- 1
发布时间：2022-10-20 - 摘要：Aiming at the comfortable and practical demand of intelligent multifunctional care beds,a new multifunctional care bed is designed and developed. To simplify the mechanism and avoid the interference of the carry back mechanism and the bed-chair mechanism,a new motor used to rotate the backrest is adopted to replace the traditional electric push-rod. The simulation analysis of the carry back mechanism is carried out with the ergonomics simulation software,the torque variation law of the new motor and the slippage of the back of the human body relative to the backrest during carry back motion are determined. Three kinds of slippage compensation programs are discussed and analyzed and an experimental prototype is made to test feasibility.关键词：Care bed;Carry back mechanism;Joint motor;Ergonomics;Slip mechanism
- 4
- |
- 431
- |
- 1
发布时间：2022-10-20 - 摘要：A new structure of Reluctance linear-rotary magnetic gear（ RLRMG） is proposed. The poles on screw and nut are composed of semi-oblique ring type permanent magnetic and soft magnetic,and call the poles as convex tooth. The permanent magnetic and soft magnetic convex tooth are arranged alternately. The permanent convex teeth on the screw and nut are both radially magnetized and the magnetized direction is opposite.The static characteristics of RLRMG are simulated with FEM. It is proved that the RLRMG can realize smooth transmission. The concept of Pole pitch ratio（ PPR） is proposed in order to describe the relationship of pole width and pitch. The relationship between PPR and static characteristics of RLRMG,thrust density and specific thrust are investigated with simulation. Result shows that when PPR is in the interval( 0,0. 5],RLRMG can realize smooth transmission. When PPR is in the range of( 0,0. 3],the change of thrust force and thrust density of nut are all less than 7%. When PPR is 0. 3,the specific thrust has the maximum value,that is has the maximum pole utilization ratio. When design a RLRMG,PPR should be 0. 3.关键词：Reluctance;Permanent magnetic;Screw;Simulation analysis
- 3
- |
- 72
- |
- 0
发布时间：2022-10-20 - 摘要：Combining hart straight-line mechanism with scissors mechanism,a new type of deployable model in straight-line motion which consists of revolute joint only is proposed. Corresponding modular system named scissor-type telescoping and lifting mechanism（ STLM） is designed for achieving straight-line motion in one dimension. Firstly,modular principle of STLM is explained and the composition of the mechanism is equivalent to the sequential stacking of three kinds of modules including bottom module,middle module and top module. These modules are all composed by the deployable model. Secondly,the kinematics equations of single deployable model is established and introduced into constructing the whole kinematics equations with multi-layer modules which can be used to validate the proposed method for achieving straight-line motion. Finally,taking STLM consisted with three-layer and two-row modules as an example,the structural behavior of static stiffness for this mechanism is analyzed by simulation. Results show a good performance in the stiffness along the deployable direction.关键词：Straight line mechanism;Scissors mechanism;Deployable module;Static stiffness
- 4
- |
- 388
- |
- 1
发布时间：2022-10-20 - 摘要：The omni-directional mobile vehicle（ Automated guided vehicle,AGV） based on Mecanum wheel in industrial production has a wide range of applications. The existing control methods mainly realize the AGV omni-directional movement by controlling the AGV translation and rotation separately independently.Through analyzing the kinematics law of AGV,and a control algorithm of AGV rotation,revolution and coupling motion is proposed. The theoretical analysis,computer simulation and experiments prove the effectiveness of the proposed algorithm. The proposed algorithm can be extended to an arbitrary curve path,which may have a great practical significance.关键词：Mecanum wheel;Omni-directional vehicle;Control algorithm
- 6
- |
- 518
- |
- 5
发布时间：2022-10-20 - 摘要：The simple tribo-dynamics model for TI hourglass worm drive is proposed based on the load sharing theory and dynamic theory,which took the time-varying mesh stiffness,transmission error and friction coefficient of rough peak into account. The tribo-dynamics character is considered into line contact Elastohydrodynamic Lubrication（ EHL）. The meshing force and friction changes,oil film pressure and thickness distribution are obtained by calculation. The calculation results show that,when at low speed,the meshing force and friction of the tooth are larger than those at high speed. With the increase of the helix angle,the meshing forces both at inlet and outlet are obviously improved,and the friction of the tooth changes a little with the speed.Meanwhile,the maximum friction reduces,which can improve the transmission life of the worm drive pair. The meshing stiffness of the tooth has the greatest impact on oil film pressure and thickness,and the meshing force and friction coefficient of rough peak have less influence correspondingly.关键词：TI hourglass worm drive;Tribo-dynamics;Elastohydrodynamic lubrication;Oil film pressure;Oil film thickness
- 5
- |
- 118
- |
- 0
发布时间：2022-10-20 - 摘要：Aiming at the problem of a company dual clutch automatic transmission 2 nd gear whine,a virtual prototype model of the transmission is established by using Romax software. Based on the original simulation results of gear modification parameters,two new designs are proposed,plan A and B,to make sure per unit length load and contact stress concentrated in the center of the gear and the Peak to peak transmission error（ PPTE） values are the minimum. The plan A is to cancel tooth tip relief,plan B is to reduce the helix slope deviation and given the adjustment range,and then the same simulation with the original is carried out. The optimal B is obtained by comparison and analysis of the simulation results of the adjustment range of plan B to be a comparison of plan A. Finally,the NVH experiment of the vehicle is carried out to verify the simulation results of plan A and optimal B. The verification results show that optimal B performs better than plan A by reducing the Sound pressure level（ SPL） obviously and controlling the main order noise 40 d B below under drive conditions through gear modification. The gear whine problem of transmission 2 nd gear is solved eventually,the vehicle NVH performance is improved better.关键词：Transmission;Peak transmission error;Gear modification;NVH
- 6
- |
- 152
- |
- 1
发布时间：2022-10-20 - 摘要：By analyzing the structure of Tripod parallel robot,a single branch chain analysis model is established. The kinematics analysis of robot is carried out by means of geometric analysis,and the expression of inverse kinematics is obtained. On the basis of the inverse solution analysis,the forward kinematics analysis formula is solved,and by using the numerical method of Newton iteration,the forward kinematics position is calculated. Combined with specific examples,the feasibility of kinematics analysis is verified by using MATLAB software programming. In order to further study the performance of the robot,according to the inverse kinematics of the robot,the workspace of the robot is analyzed. According to the Jacobi matrix of the robot,three kinds of singular configurations of the mechanism are discussed. Finally,the workspace map is drawn by MATLAB software program with the size parameters of the mechanism.关键词：Tripod parallel robot;Kinematics analysis;Workspace;Singular configuration
- 3
- |
- 200
- |
- 5
发布时间：2022-10-20 - 摘要：Aiming at collaborative space problem of the dual arm 6 R service robot,the Monte Carlo and traversal search comparison method are used for analysis according to its configuration characteristics. Firstly,according to the configuration of the manipulator,the standard DH method is used to construct the model,and then the forward kinematics equation of the arms is obtained. Secondly,the work space of each arm is got by using Monte Carlo method. Then,the collaborative space of the arms is obtained by using the traversal search comparison method,and the range of the joint angle of the dual arms is obtained through kinematics inverse method. Finally,the MATLAB toolbox is used to build the simulation platform and the algorithm is written to verify the correctness of the above analysis,and the foundation for the follow-up coordinated operation and trajectory planning is laid.关键词：Dual arm;Monte Carlo method;Traversal search comparison method;Collaborative space
- 5
- |
- 332
- |
- 1
发布时间：2022-10-20 - 摘要：A robot with rolling ability based on spatial octahedron,which consists of 6 vertex modules,12 telescopic unit expansion modules and 1 load module is designed. In order to controlling the robot to roll in a particular direction,the system changes the center of gravity by controlling the amount of expansion and contraction quantity between the telescopic rods. In this study,the process of forward kinematics solution and inverse kinematics solution of the robot are analyzed. According to the analysis,by using the ADAMS software,the dynamic simulation of the movement of the robot,which contain the simulation for gait planning and climbing obstacle capability is finished. Through the result of the dynamic simulation,the correctness of kinematics analysis is validated,and the motion curve of the robot vertices and the centroid is also obtained. The method and simulation results of the kinematics analysis of this study provide an important basis for the optimization design of the space polyhedron rolling robot.关键词：Space octahedral rolling robot;Kinematics analysis;Gait planning;Climbing obstacle capability
- 3
- |
- 145
- |
- 4
发布时间：2022-10-20 - 摘要：Based on the operating principle and cushioning characteristic of a shift clutch,the mechanical model of the shift clutch and the hydraulic model of the buffer circuit are respectively established in Recur Dyn and AMESim,then the mechanical-hydraulic co-simulation is realized through the software interface. The operating characteristics of the shift clutch with buffer circuit are analyzed,then the reliability is tested and the typical factors that affected the performance are explored. The basis for the failure mechanism and maintenance of the shift clutch is provided.关键词：Shift clutch;Buffer circuit;Recurdyn;AMESim
- 4
- |
- 172
- |
- 1
发布时间：2022-10-20 - 摘要：A new representation method of the workspace of a planar parallel manipulator is presented.Taking the 3 RRR plane parallel robot as an example,according to the iterative search method,the inverse solution equation is used as the discriminant,and the circular search of workspace is carried out. After the data processing,the three-dimensional display of the full-posture workspace of planar parallel manipulator is obtained,and its characteristics are studied. On this basis,the reachable workspace is obtained and the working space does not exist empty pole length ratio.关键词：Parallel robot;Full-posture workspace;Search algorithm
- 4
- |
- 245
- |
- 1
发布时间：2022-10-20 - 摘要：The background and significance of gear test detection platform and basic database construction are introduced,and a structural scheme of bevel gear closed power flow durability test bench including the composition and system function is proposed. The 3 D model of constant speed cylindrical gearbox is established by using Solid Works 3 D software,the statics and modal of the box are analyzed according to the actual working load of the test bench by finite element method. The maximum stress,deformation and natural frequency of the box and the corresponding vibration mode are obtained,and the result of the strength check of meshing gears verify the constant speed cylindrical gearbox meeting design requirement.关键词：Spiral bevel gear;Constant speed cylindrical gearbox;Modal analysis;Fatigue strength
- 7
- |
- 196
- |
- 4
发布时间：2022-10-20 - 摘要：In order to overcome the disadvantages of traditional denosing method always reduces useful information while it removes noise,a fault diagnosis method combining quantum superposition and probability statistic applied to rolling element bearing is proposed,which uses the specific expression in quantum theory. This method utilizes Laplace mathematics statistics models to describe the dual-tree complex wavelet transform coefficient distribution of vibration signal. On the basis that the change characteristic of noise and fault information between adjacent scales is studied,then quantum superposition is employed to distinguish fault information from noise in vibration signal. The rolling element bearing signal from transmission system with fault is used to verify the validity of this proposed approach. The results reveal that this method can effectively enhance fault information while it reduces noise,thus it can extract mechanical fault information from intensive background noise.关键词：Vibration;Fault;Quantum superposition;Statistics model
- 4
- |
- 74
- |
- 0
发布时间：2022-10-20 - 摘要：In order to solve the problem that large items are not convenient to be carried under the condition without elevator,an electric auxiliary stair climbing machine based on the slider-crank mechanism is designed,in which 24 V lithium battery is used as the power supply and a decelerating motor is used as power output mechanism of the stair climbing machine. The optimization of slider guide inclination is analyzed by using motion of UG software. Through the experiment of the physical prototype,the distance difference between the slider movement between the highest point and the lowest point is 17. 674 cm,which meets the coordination standard of the building staircase module of our country. The analysis of ANSYS shows that the strength meets the stress requirements during the movement of the stair climbing machine,the stair climbing machine can run smoothly on the stairs,the safety and reliability of the stair climbing process will be ensured through the mechanical structure.关键词：Load;Electric auxiliary;Slider-crank mechanism;Stair climbing machine
- 5
- |
- 437
- |
- 4
发布时间：2022-10-20 - 摘要：In order to improve reliability of wind power unit drivetrain,a fault diagnosis model based on quantum genetic algorithm and support vector machine（ SVM） is presented. The model of SVM is conformed,and the penalty parameter and Kernel function coefficient are optimized by quantum genetic algorithm,which coding and renewal of initial population are completed with quantum encoding and rotation gate,the accuracy of optimal solution is improved. Through using the optimized SVM model,with the test and calculation for drivetrain in three types of normal condition,surface wear and missing teeth,the accuracy rate of fault diagnosis can be effectively solved.关键词：Wind power unit;Drivetrain;Fault diagnosis;Support vector machine;Quantum genetic algorithm
- 3
- |
- 200
- |
- 4
发布时间：2022-10-20 - 摘要：In order to study the influence of modification of cycloid gear and bearing clearance on angular transmission error of RV reducer,based on the multi-body dynamics simulation technology,multi-body contact between gears is established by combining with the most advanced mixed contact checking algorithm rely on relative coordinate contact configuration space method and boundary box method,furthermore the spring force element is used to eliminate the redundant constraints in the dynamic simulation model,at the same time the bearing clearance is introduced,at last the dynamic simulation model of RV reducer containing the cycloid gear modification and bearing clearance is established. Then the angular transmission error of RV reducer under the condition of special tooth profile modification of cycloid gear and different quantity of bearings clearance are checked by multi-body dynamics simulation,which providing a new modeling ideas and methods for studying the effect of cycloid gear profile modification and bearing clearance on angle transmission of RV reducer with multi-body dynamics simulation.关键词：RV reducer;Angular transmission error;Multi-body dynamics simulation;Virtual prototype;Contact
- 4
- |
- 352
- |
- 1
发布时间：2022-10-20 - 摘要：The high power transfer case as a key component of a multi-axis super-heavy chassis transmission system,with the characteristics of large torque,high speed,and large temperature difference,rely on splash lubrication and natural air cooling has been unable to meet the need of the chassis for high mobility,high through off-road and extreme ambient temperature. It is necessary to use the forced lubrication system to lubricate the internal hot spots of the transfer case,especially the bearing position. Therefore,the power thermal energy model of the hotspots of the transmission parts is built first,through the heat balance conditions,the flow demand of the lubrication point and the overall are estimated,and then a hydraulic simulation analysis model is established,the matching lubrication system piping is designed. Aiming at the problem of the natural air cooling can’t achieve the system thermal balance requirements in the great power of the transmission system,by calculating the surface wind speed and heat dissipation surface,the heat dissipation capacity of the transfer case itself is evaluated,the external air-cooled radiator and fan are matched according to the heat dissipation requirement.Finally,through the bench and running vehicle test,the design of the high power transfer case forced lubrication system to meet a multi-axis super-heavy chassis of the use of the requirements is verified.关键词：Transfer case;Lubrication system;Cooling system;Experimental research
- 5
- |
- 81
- |
- 1
发布时间：2022-10-20 - 摘要：A group of long pinion-to-short pinion planetary gears are added into the traditional Ravigneaux planetary gearset and one planetary gear meshes with two others. This new type Ravigneaux planetary gearset can improve the capability of the automatic transmission in the aspect of power and torque. The essential constrain conditions are established by analyzing the structure of the Ravigneaux transmission. The assembly condition minimum error can be calculated by the essential constrain conditions and the condition that make a planetary gear meshes with two others properly. That is the objective function of the design and 17 groups feasible programs are yielded finally.关键词：Ravigneaux planetary gear set;Long pinion-to-short pinion mesh;Assembly condition;Automatic transmission
- 4
- |
- 296
- |
- 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