最新刊期
期 7 ， 2018
- 摘要：In order to analyze the influence of internal excitation factors on tooth surface vibration of cylindrical herringbone gear,the herringbone gear vibration model is established considering time-varying meshing stiffness excitation,corner mesh impact force excitation,and the backlash influence. The influences of internal excitation factors on tooth surface vibration of cylindrical herringbone gear are calculated according to different load and speed conditions. Taking the one-stage herringbone gear transmission system as an example,the simulation results consistently show that meshing stiffness excitation is the main influencing factor on vibration of herringbone gear. The influences of backlash increase with the rotation speeds increase,but decrease with the loads increase. Those influence rules provide a more reasonable design target for the follow-up tooth surface vibration and noise reduction optimization.关键词：Cylindrical herringbone gear;Stiffness excitation;Impact excitation;Vibration influence;Proportion analysis
- 3
- |
- 166
- |
- 1
发布时间：2022-10-20 - 摘要：The second-order logarithmic superposition of modification quantity along the normal direction to the theory of conjugate tooth profile of cycloid gear of RV reducer is carried out,the cycloid tooth profile equation after the modification is deduced. By controlling the base number of the tooth profile modification and the coefficient of the tooth profile modification,the modification quantity control of the tooth profile curve at different position can be achieved. The difference between the second-order logarithmic profile modification method and the traditional parabola method is that the cycloidal wheel mainly involved in the tooth profile of the meshing working section is more closely to the theoretical tooth profile. The contact ratio of second-order logarithmic tooth profile modification is bigger,the transmission error curve has better symmetry,and the cycloidal wheel drive is more stable. This modification method has the advantages,a new way of thinking for the modification design of high precision RV reducer cycloid gear is provided.关键词：High accuracy RV reducer;Cycloid wheel;Logarithmic modification;Tooth profile equation
- 4
- |
- 329
- |
- 1
发布时间：2022-10-20 - 摘要：Considering the creep characteristics of the rubber bearing material,the infinite line contact model of the water-lubricated bearing is established,based on the Kelvin model and the three-parameter model,the elastohydrodynamic lubrication of water-lubricated rubber bearings is analyzed. The effects of creep of rubber bearing on the pressure and film thickness of the lubricating membrane are obtained. The effects of the central pressure,the central film thickness and the minimum film thickness under the influence of the two models are analyzed and contrasted. The results show that the creep characteristics of the rubber bearing has great influence on the pressure and the thickness of the lubricating membrane. Under the two creep models,the pressure of the lubricating film decreases with the creep time,and the thickness of the lubricating film increases with the creep time,at the same time the contact area is increasing to the end of the constant value. The central pressure increases with the creep time and tends to be stable. The minimum film thickness decreases with the creep time and then decreases to the steady value. After the creep stabilization,the pressure and film thickness of the two models are larger than those of the rubber bearing as the linear elastomer. Compared with the previous work,the three-parameter solid model can describe the lubricating performance of the rubber bearing better than the Kelvin model.关键词：Water lubrication;Rubber bearing;Creep;Kelvin model;Three parameter model
- 2
- |
- 144
- |
- 1
发布时间：2022-10-20 - 摘要：In order to solve low accuracy and inefficiency of tooth crest chamfering for spiral bevel gear,a method of tooth crest chamfering by using disc cutter is proposed. Gear solid model with the chamfering feature is established,crest lines are used as sweep path to create cylinder sweep volumes. Position relationship between gear and disc cutter is determined based on intersecting lines of cylinder sweep volumes,then machining parameters of chamfering are calculated. Simulation environment for chamfering is established including machine,disc cutter and gear,some groups of machining parameters are set to simulate machining process. The shape errors of chamfering are measured,optimized machining parameters are determined by aiming the minimization of shape errors. This method can be realized by installing disc cutter on gear milling machine which means special purpose machine is unnecessary. The disc cutter has longer cutting circumference compared to other shape cutter,which can prolong cutter life effectively.关键词：Spiral bevel gear;Disc cutter;Chamfering;Cutting simulation;Shape error
- 4
- |
- 65
- |
- 1
发布时间：2022-10-20 - 摘要：The judgment of the rigid subchain is a difficult problem in the synthesis of kinematic chain.By analyzing the kinematic chain of each closed loop in the kinematic chain,a method is proposed to determine whether there is the rigid subchain in the kinematic chain. According to the composition of the basic loop of the kinematic chain,the method of establishing the basic loop matrix is proposed. Through the operation of the basic loop matrix,the combined closed loop in the kinematic chain is obtained. The rigid subchain in the kinematic chain is got by combining the rigid subchain identification method. By the operation of the basic loop matrix,the closed loop of the rigid subchain is eliminated,and the kinematic chain without the rigid subchain is obtained. Finally,computer programming is used to realize the automatic recognition and elimination of the rigid subchain.关键词：Kinematic chain;Rigid subchain;Automatic identification and elimination
- 4
- |
- 74
- |
- 1
发布时间：2022-10-20 - 摘要：Considering the advantages of the circular arc gear and the face gear,the gear drive with circular arc tooth profile is put forward. In order to advance the machining application of the face gear,the face gear blank size must be determined. By using the envelope forming theory,the tooth surface equation of the circular arc tooth profile is deduced,and the contour visualization is realized in MATLAB,and it is concluded that the tooth tip has two sharpening in the radial direction. The factors that affect the radius of the tooth tip sharpening are analyzed and calculated according to the numerical calculation. A special case with a helix angle of 0° is proposed and the approximate equation of inner diameter and outer diameter of tooth tip sharpening is obtained by least squares method. Finally,the feasibility of the theoretical calculation and the approximate equation is proved by the simulation experiment.关键词：Circular arc tooth profile;Face gear;Tooth tip sharpening;Least square method;Envelope forming
- 4
- |
- 80
- |
- 1
发布时间：2022-10-20 - 摘要：For improving the reliability and efficiency of the dynamics analysis for planar linkage,the corresponding vector bond graph procedure based on generalized velocity is proposed. By the kinematic analysis of mechanism,the relation matrix between mechanism velocity vector,the capacitance field velocity vector,the inertia field velocity vector,the resistive field velocity vector,the source field velocity vector and generalized velocity vector are established. Based on these,the vector bond graph model of planar linkage based on generalized velocity is established. By the corresponding algorithm,the automatic dynamics modeling,calculation and analysis of planar six bar press mechanism on a computer is realized,the influence of pulse working load on mechanism driving moment is revealed,and the validity of the procedure proposed is verified.关键词：Generalized velocity;Vector bond graph;Planar linkage;Driving moment;Pulse working load;Causality
- 4
- |
- 125
- |
- 1
发布时间：2022-10-20 - 摘要：To improve the lubrication performance,anti-scuffing capacity and efficiency of enveloping worm,the elastohydrodynamic lubrication（ EHL） line contact model is established based on the research of meshing performance of inclined double-roller enveloping hourglass worm drive and the theory of EHL. According to the line contact mathematical model with Ree-Eyring fluid,the distribution of the minimum film thickness of EHL and thermal EHL（ TEHL） are analyzed. The roller radius,offset distance,orifice coefficient and inclined angler,which impacted the lubrication performance of this worm drive are analyzed. The analysis results indicate that the inclined double-roller enveloping hourglass worm drive has better lubrication performance,the roller radius and orifice coefficient have the biggest impact on TEHL. In order to keep good lubrication performance of this worm drive,the roller radius should be not too large,the offset distance and orifice coefficient are not too small.关键词：Double-roller;Hourglass worm gear drive;Elastohydrodynamic lubrication;Ree-Eyring fluid;Minimum film thickness
- 4
- |
- 81
- |
- 3
发布时间：2022-10-20 - 摘要：A new method of finite element mesh generation is proposed based on meshing characteristics of helical gear. The contact line in the process of engagement could pass through the unit nodes successively. The flexibility coefficient matrix is obtained by finite element method. Tooth contact analysis（ TCA） model for helical gear is established considering the interaction between participating and non participating meshing point. By introducing boundary and deformation compatibility conditions,the equilibrium equations are established and solved. Finally,the time varying meshing stiffness,tooth surface elastic deformation and load distribution are calculated,moreover compared with the calculated meshing stiffness according to GB/T 3480-1997,the results show that the proposed method is effective.关键词：Helical gear;Finite element;Meshing stiffness;Tooth surface load distribution
- 2
- |
- 422
- |
- 8
发布时间：2022-10-20 - 摘要：Based on the theory of the position and orientation characteristic set（ POC）,the theoretical connotation of topology analysis of the parallel mechanism is revealed,a description method of parallel mechanism topology based on neural network is built,an automatic analysis algorithm of parallel mechanism topology mechanism based on neural network is presented. A detailed description of the algorithm in 6 rules parallel mechanism POC set model and the neural network model is introduced,the main steps and examples analysis of the method are given. First of all,by analyzing the topological structure of parallel mechanism,the essence is summed up. Secondly,based on the neural network theory,the topological structure of parallel mechanism is described and digitized. In addition,by analyzing the essential meaning of the automatic analysis of POC sets of parallel mechanisms,the POC neural network model of parallel mechanisms is established and 6 algorithm rules of the model are proposed. Finally,an example is given to prove the correctness and effectiveness of the POC set automatic analysis algorithm for parallel mechanism.关键词：Parallel mechanism;Position and orientation characteristic set;Vector Set;Automatic analysis
- 4
- |
- 80
- |
- 3
发布时间：2022-10-20 - 摘要：In order to manufacture the Klingelnberg cyclo-palloid bevel gear on domestic CNC spiral bevel gear cutting machine,the processing method with monolithic cutter disc is researched. Based on the cutting principle of cyclo-palloid bevel gear,the processing method which the gear is machined by spread blade method and the pinion is machined by single side method is proposed. According to the structure parameters of two-part cutters,the method for designing cutter-head and cutter blade of monolithic cutter disc is proposed.According to the curvature relationship between the meshed tooth flanks,a method for determining the amount of modification of cutter radius is established by iteration algorithm. According to the cutting principle and gear meshing theory,the formula for calculating the machine setting parameters and cutter parameters are derived.The processing experiment is completed on domestic CNC spiral bevel gear cutting machine with monolithic cutter disc. The correctness and feasibility of the cutting principle is verified by the rolling test of the experimental work piece.关键词：Cyclo-palloid bevel gear;Monolithic cutter disc;Cutting principle;Machine setting parameter
- 5
- |
- 98
- |
- 2
发布时间：2022-10-20 - 摘要：With the 6-DOF manipulators of the multi-arm casting robot as the research object,the trajectory planning is designed by the 4-3-4 polynomial interpolation method in the joint space. Under the constraint of velocity,the breed algorithm is used to optimize the interpolation results to obtain the optimal motion time of manipulator. Contrast to the particle swarm optimization,the breed algorithm has the higher precision and more rapid speed in the convergence procedure. By means of the Matlab,the movement position,velocity and acceleration curve of each joint of the dual arm robot are obtained. The consequence shows this method can accurately realize the time optimal trajectory planning at the speed constraint.关键词：6-DOF manipulator;Breed algorithm;Trajectory planning;Polynomial interpolation;Speed constraint
- 3
- |
- 248
- |
- 2
发布时间：2022-10-20 - 摘要：In order to help patients with lower extremity dysfunction complete walking rehabilitation training,a plantar-driven walking aided training robot mechanism is designed. According to the change laws of ankle and knee joint posture during normal walking,the dimensional synthesis optimization of ankle joint attitude restraining mechanism and aided knee flexion mechanism is carried out to determine the optimal size parameters of the mechanism. According to the rotation laws and range of the plantar,the trajectory of restraint guide rail ζof ankle joint attitude restraining mechanism is comprehensively determined,and the effects of confined guide way inclination angle and pedal length on the angle range of ankle joint are analyzed. The aided knee flexion mechanism is designed to help the affected limbs flexibly in the knee during walking training,and the influence of mechanism dimension on the aided knee flexion is analyzed and determined. The simulation model of the mechanism is established by using the Matlab toolbox,and the rationality of dimensional synthesis optimization and the feasibility of robot mechanism design is verified by the results of simulation analysis.关键词：Rehabilitation robot;Gait training;Dimensional synthesis design
- 3
- |
- 200
- |
- 0
发布时间：2022-10-20 - 摘要：Based on the theory of dimension chain,the dimension chain compute with extremum method and probability method is researched. It defines that compute method determined by the number of composition loops,the real statistical data and the statistical process control ability can be used to optimize the dimension chain. Usually,the structure of gearbox is complicated,but the accumulative error must be controlled in a minor range. That method can avoid severe dimension tolerances of components and parts in the design of gearbox,meanwhile products can be manufactured reliably and economically.关键词：Dimension chain;Statistical process control ability;Optimum design
- 5
- |
- 160
- |
- 1
发布时间：2022-10-20 - 摘要：As the basic unit of complex transmission,two-row parallel planetary gear mechanism needs to be considered as whole in transmission ratio computation. According to the design requirements of vehicle automatic transmission,the design procedure for two-row parallel planetary gear mechanism is proposed based on the lever method using 3-node unified single-row single-stage and two-stage model,and the principle are illustrated by diagram. A new type of two-row parallel planetary gear mechanism（ single-stage and two-stage CC-SS） is designed and compared with the classical transmission A341 E（ single-stage and single-stage CR-SS）,4 T65 E（ single-stage and single-stage CR-RC）,AG4（ single-stage and single-stage CC-RR） and the transmission（ different case of single-stage and two-stage CC-SS） from a certain car,results show the new type of gear mechanism overall has obvious advantages of larger transmission ratio range,small transmission ratio step and least shifting components.关键词：Lever method;Planetary gear mechanism;Transmission
- 3
- |
- 193
- |
- 2
发布时间：2022-10-20 - 摘要：The support methods and life calculation methods of the planet gear bearings in planetary reducer are discussed. Combining with dual-mode cutting reducer The example calculations are carried out.Several factors that affect the bearing life are simulated and analyzed by using KISSsoft. Finally,the considerations for the design of the planet gear bearing for Cutting reducer are put forward and the reference for similar design in the future is provided.关键词：Cutting reducer;Planetary gear;Bearing;Modified rated life
- 4
- |
- 70
- |
- 0
发布时间：2022-10-20 - 摘要：In view of the increasing request of NVH（ noise,vibration,harshness） performance in automotive transmission,the dynamic response characteristics under the internal excitation of transmission are explored. Taking the gear pair transmission error as input condition,the dynamic compliance method is used to solve the dynamic meshing stiffness on the basis of the gear pair force analysis. By combining the transmission error and the dynamic meshing stiffness output the gear pair dynamic meshing force,the dynamic response of the bearing is solved by decoupling the dynamics equation of the gear drive system with the principal coordinate transformation. The dynamic response of a certain gearbox output stage with dynamic meshing stiffness is analyzed and compared with the vibration response test results. The results show that the overall error of the analyzed dynamic response results based on dynamic meshing stiffness and the response test results is within 3 μm,and the two are in good agreement. The reliability of the dynamic response analysis of gearbox through dynamic meshing stiffness is verified,which provides a theoretical basis for the design of gearbox.关键词：Dynamic compliance method;Dynamic meshing stiffness;Transmission error;Time-varying mesh stiffness
- 4
- |
- 170
- |
- 1
发布时间：2022-10-20 - 摘要：A new type of 2 PRS/2 PUS parallel mechanism is used to calculate the degree of freedom,and the output characteristics of the mechanism are analyzed. The inverse kinematics equation of the mechanism is established by combining the numerical algorithm with the Euler angle algorithm. In addition,the constraint conditions of the components are analyzed in detail,and the working space is solved by the comparison search method with the help of MATLAB software,moreover,the working space of the mechanism is analyzed. The research shows that the working space of the mechanism has the advantages of symmetry,no cavity and section shape regulation. The analysis results provide a theoretical basis for further research on this kind of parallel mechanism with a few degrees of freedom.关键词：Parallel mechanism;4-DOF;Inverse kinematics;Constraint condition;Workspace
- 4
- |
- 237
- |
- 5
发布时间：2022-10-20 - 摘要：Based on the principle of meshing,by analyzing the Gleason dual helical motion,a tooth cutting calculation method for the double-sided machining of quasi-hyperboloid bevel gear with small module is proposed,and the relevant formulas are also deduced. This calculation method provides a theoretical foundation for the double-sided machining process of spiral bevel gears with small modulus.关键词：Double-sided helical motion method;Tooth cutting calculation;Quasi-hyperboloid bevel gear;Surface face modification
- 4
- |
- 93
- |
- 1
发布时间：2022-10-20 - 摘要：Gear tooth surface error is main excitation source of vibration and noise in gear system. In order to study the influence of tooth surface error on gear system,the static transmission error is calculated for gear system with measured errors such as profile deviation,run out and pitch errors by tooth contact analysis method.In this work,a differential equation of vibration for gear system with time-varying meshing stiffness,blackness,meshing damping and static transmission error is established on the basis of previous research for gear transmission system. The dynamic characteristic of gear system is obtained by numerical analysis method. The results show that static transmission error with measured errors has more actual components. The profile deviation has higher influence on gear system at low rotation speed,and run out and pitch error have higher influence on gear system at high rotation speed.关键词：Measured tooth surface error;Dynamic characteristic;Static transmission error;Gear
- 3
- |
- 168
- |
- 2
发布时间：2022-10-20 - 摘要：In order to improve the lapping quality of hypoid gears,based on real tooth surface,an approach for lapping position control of hypoid gear is proposed. According to the measured results of real tooth surface of hypoid gears,the non-uniform rational B-spline（ NURBS） surface is employed to fit the measured points. The tooth contact analysis（ TCA） for the real measured tooth surface is applied to analyze the mathematic relationship between the adjusting parameters（ V/H/J） of lapping movement and the meshing position.The model of lapping point control over position and movement direction is established. Finally,a numerical control rolling test is carried out. The experimental results show that the whole tooth surface lapping of hypoid gears can be exactly realized.关键词：Hypoid gear;Surface fitting;Tooth contact analysis;Whole tooth surface lapping
- 5
- |
- 74
- |
- 1
发布时间：2022-10-20 - 摘要：Based on the heat conduction theory,combining the thermal flux density,considering convective heat transfer in the groove on the friction pairs,a theoretical model of the friction pairs of the hydro viscous speed regulating clutch is established. According to the actual working condition of clutch,numerical analysis for the boundary friction stage of friction pair is performed,and the difference of temperature and deformation under different material combinations of friction pairs is studied. The results show that the temperature field of friction pairs is divided into elliptical blocks of different temperature gradient by the groove,and high temperature is concentrated near the outside diameter. Under the same conditions,the temperature and deformation is biggest when the dual material is 30 Cr Mn Si A. The internal and external diameters of the friction pairs occur positive and negative displacements along the z axis,and disc buckling occurs. It is found that only 30 Cr Mn Si A doesn’t undergo plastic deformation in case of the outer diameter having constraint. This is meaningful for the mechanism of hydro viscous transmission and active design of friction pairs.关键词：Hydro viscous speed regulating clutch;Temperature field;Stress field;Coupling
- 3
- |
- 63
- |
- 1
发布时间：2022-10-20 - 摘要：To simplify the kinematics expression and to increase the motion response speed for manipulators,a kinematics modeling method is proposed based on dual quaternion. First,to reduce the computational amount,the general equation of the forward kinematics of the manipulator is presented using dual quaternion.Then,to solve the inverse kinematics problem of the assembled joint variables of manipulator,the sub-problems are classified into two groups of uniaxial and biaxialox,this classification method includes the existing sub-problem classification,which is beneficial to the joint variable grouping solution. Finally,taking a 6 R series manipulator as an example,the forward kinematics and inverse kinematics modeling and simulation analysis based on the dual quaternion are carried out. The results show that this method is effective,comparing with the spinor method,its calculation time of forward kinematics is reduced by about 30%,the geometric meaning of inverse kinematics is more clear. This method can be applied to other sub-problems solution of the manipulator configuration.关键词：Manipulator;Kinematics;Dual quaternion;Sub-problem
- 8
- |
- 272
- |
- 4
发布时间：2022-10-20 - 摘要：Taking the high-precision 2 K-V20 reducer for industrial robots as the research object,by using the technology of multi-flexible-body dynamics,the rigid-flexible coupling model of the reducer is established in Recur Dyn. The motion characteristics of each part are analyzed through virtual prototype simulation,and the result is approximately with the theoretical value,which testifies the correctness of the model.Based on this rigid-flexible coupling model,some models with different error sources are established,and their effects on the reducer transmission error are analyzed through simulation. The conclusion could provide some reference value for the designing and manufacturing of the 2 K-V reducer.关键词：2K-V reducer;Rigid-flexible coupling;Virtual prototype;Transmission error
- 4
- |
- 120
- |
- 2
发布时间：2022-10-20 - 摘要：Based on the NGW planetary gear transmission system,a gear transmission of parallel uniform planetary gear is proposed to reduce the transmission error of asteroid transmission system and improve its transmission accuracy. The backlash formula is obtained by considering the influence of gear eccentricity error and working load on the backlash of planetary transmission system. The influence of load and gear eccentricity error on the transmission system is analyzed. The results show that,as the working load increasing,the backlash of gear transmission of parallel Uniform Planetary gear and NGW planetary gear transmission system are all increased. But the backlash of NGW planetary gear transmission system is slightly larger. Under the condition of same gear eccentricity error,the backlash of gear transmission of parallel uniform planetary gear is less than the backlash of NGW planetary gear transmission system. In the gear transmission of parallel uniform planetary gear,the eccentricity error of the solar wheel has a great impact on the transmission system,but the eccentricity error of the outer ring has less influence on the transmission system. The influence of planetary wheel eccentricity error on the transmission system is between sun wheel and planet gear.关键词：Planetary transmission;Parallel uniform distribution;Backlash
- 5
- |
- 82
- |
- 2
发布时间：2022-10-20 - 摘要：According to working principle of transmission,the heat generation mechanism of transmission is analyzed. According to new energy two gear transmission lubrication test requirements,the lubrication test system is independently developed,and the lubrication test and temperature rise test about a new two gear transmission are carried out under different working conditions. The results show that lubrication and temperature rise of those components of transmission are related to driving speed,pitch angle and side dip angle. With the driving speed increases,changes of input shaft bearing lubrication effect shows first increased and then decreased,the output shaft bearing lubrication effect shows variation diminishing. The effect of side tip angle relative to the lubrication state of the transmission is more obvious than pitch angle. The transmission shell temperature,bearings temperature and oil temperature increased with the risen of speed. With the increase of speed,the temperature rise rate of oil is greater than that of shell and bearings,and temperature of bearings are slightly higher than shell.关键词：New energy;Transmission;Lubrication;Temperature rise;Test
- 3
- |
- 252
- |
- 2
发布时间：2022-10-20 - 摘要：The finite element model of a pair of straight bevel gears is established,and the simulation is carried out by using the ANSYS/LS-DYNA software to verify the accuracy of the simulation method. Based on this,a pair of zero spiral bevel gears are created for comparative analysis. According to the simulation results,the gear contact force,tooth surface contact stress,tooth root bending stress and vibration of large gear are compared and analyzed. It is found that the transmission characteristics of the straight bevel gear and the zero spiral bevel gear are obvious difference at the same load and speed. This provides a reference for the selection and application of these two types of bevel gears in the aeronautical field.关键词：Straight bevel gear;Zero spiral bevel gear;Finite element;Contact force;Stress;Vibra tion
- 3
- |
- 220
- |
- 3
发布时间：2022-10-20 - 摘要：The escapement mechanism is considered to be the crucial component in a mechanical watch with a complicated motion. A dynamics model of the escapement mechanism is established based on the continuous impact force model,the dynamics simulation and calculation are carried out by using ADAMS. The results show that the dynamics response of each part under different input moment of escapement wheel can be directly predicted by the model,and therefore the corresponding instantaneous daily rate is calculated. Compared with the experimental data,the simulated results are able to predict the trend of the instantaneous daily rates in different driving torques in a moderate precision level. The model could be used to improve the performance of the escapement mechanism in the future.关键词：Mechanical watch movement;Escapement mechanism;Instantaneous daily rate;Dynamics simulation
- 5
- |
- 211
- |
- 1
发布时间：2022-10-20 - 摘要：The flexible gear is the key parts of harmonic gear reducers,and its performance directly determine the overall condition of harmonic drives. In order to seek the basic law of influence of flexible gears wall thickness on its performance to make use of the law,the influences of flexible gears wall thickness on stress and deformation of the flexible gears are simulated and analyzed by ANSYS Workbench software under no-load and load conditions. The results show that,the maximum stress of the flexible gear increases and the maximum deformation decreases with the increase of the wall thickness under no-load condition. With the increase of the wall thickness,under the load condition,the maximum stress decreases overall and the maximum deformation decreases first and then tends to be gentle. Under the same wall thickness,with the increase of the load,the maximum stress and the maximum deformation both enhance and the load is more sensitive to the deformation in the places whose wall thickness are relatively thinner. Under the same conditions,the stress of flexible gear with bottom modification is smaller. This law can provide some reference for researchers.关键词：Flexible gear wall thickness;Maximum stress;Maximum deformation
- 4
- |
- 81
- |
- 1
发布时间：2022-10-20 - 摘要：In the practical condition,the fault signal of gearbox often contain multiple fault information,but the weak fault signal belongs to weak signal compared with strong fault signal and noise,therefore,the extraction of weak fault signal in complex fault is always a difficult point in rotating machinery fault diagnosis.Based on the problems above,considering that MED（ Minimum Entropy Deconvolution） has strong reduction performance of noise,the intrinsic mode function decomposed by VMD（ Variational Mode Decomposition） is distorted in strong noise environment. The VMD decomposition accuracy is determined by penalty factor α and decomposition times k. A weak fault extraction method based on MED-VMD is proposed. Firstly,the noise reduction of original signal is carried out by MED,further,the initial parameters α and k are set,the noise reduction signal is decomposed through the VMD,the correlation coefficient of the adjacent intrinsic mode function are calculated to determine the best penalty factor α and decomposition times k. Finally,the weak fault information of bearing in gearbox is extracted by the envelope spectrum analysis of the intrinsic modal function.The validity of the proposed method is verified by the simulation signal and the measured data. A new idea for weak fault feature extraction in complex fault in strong noise environment is presented.
- 2
- |
- 214
- |
- 1
发布时间：2022-10-20 - 摘要：The variational mode decomposition（ VMD） is a novel self-adaptive decomposition method without shortcomings of traditional adaptive decomposition methods,such as mode mixing and end effects. The VMD has the advantages of strong anti-noise robustness and high efficiency. The generalized Warblet transform（ GWT） is suitable for analyzing modulated signal with periodic or nonperiodic change of instantaneous frequency. Considering the advantages of VMD in decomposing signal into sub-signals,a new method is proposed to detect gear fault based on GWT and VMD in this work. The VMD can be considered as the signal preprocessing prior to GWT. The results of the experimental analysis have demonstrated the effectiveness of the proposed method.关键词：Variational mode decomposition;Generalized Warblet transform;Gear;Fault diagnosis
- 3
- |
- 184
- |
- 7
发布时间：2022-10-20 - 摘要：The gearbox vibration signal of normal and different degrees teeth break fault condition are analyzed,the chaotic characteristics of the gearbox vibration signal are verified by using the time synchronous averaging method（ TSA） to separate the linear components in the vibration signal of the gearbox and the remaining nonlinear components as the research object. The results show,the chaotic characteristic of gearbox degeneration can be effectively extracted,the existence of chaos in the vibration signal of gearbox is verified in the life-time run.关键词：Time synchronous averaging method;Gearbox;Principal component analysis;Kolmogorov entropy
- 4
- |
- 148
- |
- 1
发布时间：2022-10-20 - 摘要：The output pinion of a MW-class wind turbine yaw gearbox has been broken down after about3 years in the grid. The comprehensive analysis is carried out on the failure gears,the causes of gear damage,such as tooth fracture,design factor,production factor,factors of assembly and operation,system protection factor,etc. are analyzed one by one,the final positioning between the thrust pad bearing and yaw ring interference is the direct cause. Bladed software is used to simulate the impeller imbalance and verify the wind field.It is concluded that the deviation of the installation angle of a blade of the wind turbine causes the aerodynamic imbalance of the wind wheel is the root cause of the failure.关键词：Wind turbine;Yaw system;Sliding bearing;Yaw gearbox;Failure analysis;Bladed simulation;Impeller imbalance
- 4
- |
- 162
- |
- 1
发布时间：2022-10-20 - 摘要：As a kind of high-performance and precision transmission device with large transmission ratio,high transmission efficiency,high transmission precision,smooth transmission and low noise,harmonic reducer is more and more widely used in industrial robots,aerospace and other fields. Harmonic reducer needs to conduct a comprehensive test to ensure the performance of its reliability. Combined with domestic and foreign scholars’ research and progress on harmonic reducer testing technology,the exposition from the aspects of transmission precision,torque,stiffness,life time and integrated testing system are carried out,and the development trend of harmonic reducer testing technology is analyzed.关键词：Harmonic reducer;Testing technology;Research present status
- 4
- |
- 937
- |
- 6
发布时间：2022-10-20 - 摘要：The German Gears Data Exchange Format（ GDE） standard is one of the concrete practices of the German Industry 4. 0. In the GDE,the gear geometry,modification information,tolerance information,gear manufacturing tool information are defined and stored as XML（ Extensible Markup Language） documents,and supports user defining their custom information. The unified management of gear information by computer and can be quickly and accurately and stably exchanged in computer or network system is realized by GDE. It provides the technical basis of modern manufacturing informatization. It is widely used to control in the process chain,compare the measurement results and purchase tools in the major gear-related enterprises around Germany which achieved good results. It is of great reference to China gear industry towards Made in China 2025.关键词：Gear;Data exchange;Format standard;Industry 4.0;Made in China 2025
- 4
- |
- 121
- |
- 2
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