最新刊期
期 8 ， 2019
- 摘要：A hybrid hysteresis model consisting of SDH model and neural network in series is constructed for the special nonlinear hysteresis characteristics of the harmonic reducer in the flexible link. The SDH model is used as the pre-model of which hysteresis characteristics between the input and output signals is similar to the hysteresis characteristics of the harmonic reducer. The dynamic RBF neural network which can describe the nonlinearity is used as the post-model to make the hybrid hysteresis model to describe the hysteresis nonlinearity characteristic of the harmonic reducer. The data obtained under different frequency input signals and different load are modeled. Compared with the classical RBF neural network model and SDH model, the experimental results show that the constructed hybrid hysteresis model has high precision and strong adaptability.关键词：Harmonic reducer;Hysteresis characteristic;SDH model;Neural network;Hybrid model
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发布时间：2022-09-25 - 摘要：In order to study the influence of the random perturbation of time-varying mesh stiffness on the dynamics of the helical gearing system, based on Newton's law, a stochastic dynamics model of a six-degree-of-freedom helical gear system is established and dimensionless processing is carried out. Combining the bifurcation diagram, Poincaré map, Lyapunov exponent diagram, phase diagram, and time history diagram of system, the bifurcation characteristics of the helical gear system with considering the random perturbation of mesh stiffness are analyzed. Numerical simulation analysis results show, when the time-varying mesh stiffness of helical gears increases, the helical gear transmission system gradually shifts from periodic motion to chaotic motion by doubling bifurcation. The increase of random disturbance makes the system’s bifurcation characteristics change, and enters chaos in advance, the dynamics characteristics of the system have an essential influence. Therefore, reasonable parameters should be selected during design to ensure system stability.关键词：Helical gear Transmission system;Nonlinear vibration;Poincaré map;Chaotic bifurcation;Lyapunov exponent
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发布时间：2022-09-25 - 摘要：In order to study the influence of clearance joints on dynamic characteristics of space symmetrical deployment mechanism, based on an improved nonlinear impact force model, an space symmetrical deployment mechanism is used as an example, and comparative analysis of the numerical simulation and results of deployment process under three conditions with different clearance joints (c=0.01 mm, 0.05 mm and 0.1 mm) are carried out. The simulation results indicated that with the effects of clearance, the impact force and center orbit of the journal and bearing in clearance joint appear clear vibration, and the larger clearance sizes, the more obvious deviation. Meanwhile, with the influence of clearance joints, the space development mechanism also appearance nonlinear phenomenon during development process, and the larger clearance size, the more obvious effects of driving load on the dynamic response of the mechanism, even lead the mechanism from stable state to non-linearity again.关键词：Clearance joint;Impact force;Space symmetrical mechanism;Dynamic characteristic
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发布时间：2022-09-25 - 摘要：The shear stress,the thermal magnetization,the viscosity and the rheological properties of the magnetorheological fluid are significantly reduced under high temperature,and the damage of the thermal stress produced by the high temperature to the chain structure of the magnetorheological fluid seriously affected the transmission performance of the magnetorheological transmission.Based on the nonlinear relationship between shear modulus and magnetic field strength,the elastic modulus of magnetorheological fluid under the action of magnetic field is calculated.The temperature,thermal deformation and the distribution law of the equivalent thermal stress in the magnetorheological fluid gap are studied under the condition of the slip and the power loss of the excitation coil and the influence of the slip power,current,gap width and the winding series of the excitation coil on it is discussed.The results show that both the slip power and the excitation coil current will cause a significant increase in the temperature of the magnetorheological fluid,and the resulting thermal deformation has little influence on the structure,and the equivalent thermal stress is greatly affected.There are obvious differences in the equivalent thermal stress distribution between the working gap and the no working gap of MRF.The performance of magnetorheological transmission device can be improved by changing the width of the gap and the series of windings under the condition of constant slip and current.关键词：Magnetorheological fluid;Temperature;Slip heat generation;Current heating;Thermal-structural field
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发布时间：2022-09-25 - 摘要：In order to improve the meshing performance of the internal helical gear transmission pair, a topographic modification method of the internal helical gear is proposed. According to the principle of tooth profile and helix modification, the equation of internal helical gear modification tooth surface is deduced, the tooth profile and longitudinal modification coefficients are preset, the contact analysis (TCA) model of internal helical gear pair is constructed by using the gear meshing principle, and the transmission error under different modification coefficients is obtained, the transmission error under different modification coefficients and different loads is obtained by the finite element simulation analysis. The results show that different modification coefficients should be selected under different operating conditions in order to meeting the operational requirements, and this method provides a reference for the design of the topologically modified internal helical gear for forming grinding.关键词：Internal helical gear;Topological modification;Contact analysis;Finite element;Form grinding
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发布时间：2022-09-25 - 摘要：Aiming at the low measuring efficiency and large theoretical error for spiral bevel gear measuring using one-dimensional probe, the method of flank and pitch deviation measuring of spiral bevel gear based on three-dimensional scanning probe is investigated. Firstly, the theoretical measurement model of spiral bevel gear in the coordinate system of gear measurement center is established. Secondly, the measuring path of flank and pitch is planned according to the established measurement model. Furthermore, according to the characteristics of three-dimensional scanning probe, the mathematical expression is deduced to analyze and process the data of tooth form and tooth pitch measurement points, and the tooth form and tooth pitch deviation are obtained. Finally, the spiral bevel gear tooth form and tooth pitch measurement experiment is carried out, showing that using the three-dimensional scanning probe the measuring operation is simplified and the measurement efficiency and accuracy are improved.关键词：Spiral bevel gear;Three-dimensional scanning probe;Tooth form;Tooth pitch
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发布时间：2022-09-25 - 摘要：In view of the disadvantage of magnetorheological fluid (MRF) performance degradation at high temperature, a conical MRF and shape memory alloy (SMA) hybrid transmission method is proposed. Based on the Bingham model, the rheological properties of MRF are described, and based on the thermal effect of shape memory alloy, the influence of temperature shape memory alloy spring output force is analyzed. The transfer torque equation of conical magnetorheological and SMA composite drive is established, and its driving mechanism is revealed. The results show that the transmission torque of conical magnetorheological drive decreases with the increase of conical angle. The torque transmitted by conical magnetorheological method is larger than that by disc magnetorheological method under the same magnetic field strength and transmission radius. The friction torque produced by the slider driven by SMA spring at high temperature can compensate for the deterioration of MRF performance and ensure the stable transmission performance of the transmission device.关键词：MRF;SMA;Cone;Composite transfer torque
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发布时间：2022-09-25 - 摘要：For the flexible hinge of compliant mechanism under the action of alternating symmetrical cyclic load, the stress concentration in the weakest area of the flexible hinge is easy to cause, resulting in the fatigue failure of the flexure hinge，taking the elliptical flexible hinges in compliant mechanisms as the research object, based on the theory of pure bending in material mechanics, the calculation formula of maximum concentrated stress at the notch of an elliptical flexure hinge is derived. By using the ANSYS software, the accuracy and feasibility of the calculation formula are verified. On this basis, by introducing linear regression method, the life prediction model of elliptical flexure hinge is established, which can predict the fatigue life of elliptical flexure hinge and solve the fatigue failure problem. Finally, an example is given to verify the correctness and effectiveness of the model, an important reference for fatigue failure and life prediction of other types of flexure hinges is provided.关键词：Flexible hinge;Stress concentration;Fatigue failure;Linear regression;Fatigue life prediction
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发布时间：2022-09-25
Theory·Reserach
- 摘要：In order to improve the measurement accuracy of non-circular gears, a three-dimensional measurement method for non-circular gear tooth surfaces is proposed. According to the basic meshing principle of the non-circular gear, the tooth surface model of the non-circular gear is established, and the three-dimensional solid modeling of the non-circular gear is completed. In order to reflect the geometry information of the tooth surface more realistically, a method of sampling the tooth surface with equal arc length by using the intersection line is proposed, and the non-circular gear tooth surface is meshed. Taking the elliptical gear as an example, the three-dimensional solid model of the non-circular gear is obtained by Einscan-SP scanner. The Geomagic Qualify software is used to align the solid model with the theoretical model, and the aligned tooth flanks are meshed to obtain the three-dimensional error value of the tooth surface of non-circular gear. This method eliminates the influence of the two-dimensional positioning error on the measurement accuracy and improves the measurement accuracy of the non-circular gear.关键词：Non-circular gear;Tooth surface error;Meshing;Measurement accuracy
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发布时间：2022-09-25 - 摘要：Chewing robot is a kind of robot which can simulate human chewing behavior. Most of the existing chewing robots are 6-DOF parallel mechanisms, but the six-degree-of-freedom parallel mechanism has complex structure, high manufacturing cost and difficult control. In view of this situation, the 3-UPS/RPP parallel mechanism is used as the prototype to design a kind of low freedom parallel chewing robot based on the characteristics that human chewing movement can be divided into two stages of chopping and grinding. Then the CAD model is established in the 3D modeling software UG, and related kinematics analysis is carried out. Subsequently, the motion simulation of chopping and grinding is carried out in the virtual prototype analysis software Adams. The results show that the chewing robot can simulate the human chewing performance.关键词：Chewing robot;Low degree of freedom parallel mechanism;Kinematics analysis;Motion simulation
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发布时间：2022-09-25 - 摘要：A two-degree-of-freedom arm rehabilitation robot with two-link series structure is designed for the requirements of upper limb rehabilitation training. Firstly, the forward and inverse kinematics of the robot is analyzed based on D-H method. The forward and inverse kinematics theory model and mechanism model of the robot are established and analyzed by using Matlab/Simulink and SimMechanics toolbox. The analysis results verify the correctness of robot kinematics modeling. According to the ergonomics related standards and the arm joints range requirements, a co-simulation model of the robot and arm mechanism is established to determine the workspace of robot. The trajectory planning of the robot for drawing circle training is completed, which laid the foundation for robot motion control. Finally, the dynamics model of the robot is established based on the simultaneous constraint method, the driving torque of each joint is determined, a basis for the selection of driving motors and controller parameters is provided.关键词：Arm;Rehabilitation robot;Kinematics;Dynamics
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发布时间：2022-09-25 - 摘要：A novel parallel metamorphic mechanism of 2-PrRS-PRS mechanism that can change the orientations of the axis of the revolute pair is designed based on the theory of metamorphic mechanism that change the orientation of kinematic pairs can lead to configuration transformation. This mechanism consists of three kinematic chains fixed on base plate and moving plate. To change the output and workspace, the revolute pair of two kinematic chains can change its rotation axis by the prismatic pair which is the drive pair. According the characteristic of the mechanism, the degree of freedom is analyzed using the screw theory. By using closed vector method and geometric constraint, the forward position and the inverse solution of the mechanism are built, and the velocity and acceleration equation of the mechanism are obtained by derivation. By using Matlab, the parameters of the mechanism and positions are substituted into, the forward and inverse solutions are solved, the figure of position and orientation is drawn. The correctness of theoretical analysis is verified by Adams simulation.关键词：Parallel mechanism;Metamorphic mechanism;Kinematics analysis;Kinematics simulation
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发布时间：2022-09-25 - 摘要：Aiming at the deficiency of optimizing the speed ratio of multi-gear transmission of electric vehicle only under a single specific working condition, which is much different from the actual working condition, a speed ratio optimization method based on particle swarm optimization (PSO) algorithm is proposed to optimize the efficiency of the common operating area of the transmission system, that is, to find the common operating area of the electric vehicle through the superposition of various specific working conditions, and to make the high efficient area of the transmission system of the electric vehicle fall into the common operating area as possible as possible by adjusting the speed ratio so as to make the average operating efficiency of transmission system is the highest. Taking the power performance of the vehicle as the constraint condition, taking the average efficiency of the driving system as the economic objective, the acceleration time as the dynamic objective, the fitness function is constructed. The speed ratio optimization is realized by using Matlab software,and the vehicle energy consumption is verified by using AMESim software. After optimization, the dynamic performance of the whole vehicle is improved, indicating that the method used in this paper is effective.关键词：Electric vehicle;Speed ratio optimization;Multi-gear;Particle swarm optimization algorithm;Transmission system;Efficiency
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发布时间：2022-09-25 - 摘要：Using Matlab software and three-dimensional finite element method, the flexibility matrix of spur gear tooth surface is obtained, and three calculation methods of matrix are compared and analyzed. The mesh stiffness of spur gear pair is obtained by establishing two kinds of loaded tooth contact analysis (LTCA) models, including line-contact and face-contact model. The effects of wheel flange thickness, web thickness,applied load and different contact models on mesh stiffness are analyzed.The results show that the mesh stiffness difference obtained by two kinds of contact model is small. When the flange thickness is small, the meshing stiffness is greatly affected while the web thickness has little effect on the mesh stiffness. In the given example, the influence of flange thickness on meshing stiffness tends to be gentle when the ratio of flange thickness to modulus is more than 3.5.关键词：Gear;Finite element analysis;Mesh stiffness;LTCA
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发布时间：2022-09-25 - 摘要：A combined mechanism which can realize constant speed reciprocating motion of its follower is presented. The mechanism is composed of a pair of non-circular gears and a sine mechanism in series. When the driving gear rotates at the fixed speed, the constant-velocity reciprocating motion of the follower in the sinusoidal mechanism can be strictly realized. An inverse kinematic design method is researched to determine the pitch curves of the non-circular gears according to the constant speed reciprocating motion of the follower and different pitch curves of the non-circular gears are obtained. All these works prove that the combined mechanism can be effectively realized the uniform motion of the follower. The combined mechanism can be widely used in the main drive systems of the machines that need to realize the constant speed motion accurately and transfer high power such as the reciprocating fatigue testing machine, shock absorber tester with mechanical transmission mechanism, etc.关键词：Non-circular gear;Sinusoidal mechanism;Pitch curve of non-circular gear;Kinematics design
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发布时间：2022-09-25 - 摘要：Aiming at the application requirements of climbing on rough walls and ceilings, an inchworm-inspired wall-climbing robot is proposed. The robot adopts a locomotion mode similar to that of an inchworm. Its two feet attach on the wall surfaces alternatively, and its body flexes and stretches to complete the forward, backward and wall transition movements. The grasping principle of the inchworm feet is analyzed and the bionic spiny gripper is designed. The statics and kinematics analysis of the robot during climbing process are carried out. The robot prototype is developed and several climbing experiments and tests are carried out. The results show that the inchworm-inspired wall-climbing robot can climb on rough walls and ceilings with the ability of transition between walls.关键词：Inchworm-inspired robot;Wall-climbing robot;Spiny gripper;Rough wall
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发布时间：2022-09-25 - 摘要：An uncoupled spatial translational parallel robotic mechanism with three degrees of freedom (DOF) is presented, which is composed of a moving platform connected to a fixed platform by three identical kinematic chains. Based on the screw theory, the kinematic output characteristic of the mechanism is analyzed. The analytical expressions of position, velocity and acceleration are derived. The form of Jacobian matrix is 3×3 diagonal, so it reveals that the inputs of the actuated joints and outputs of the moving platform satisfy one-to-one corresponding relationship, respectively. Then, the kinematic simulation of this parallel mechanism is carried out by Matlab and SolidWorks software, and the position, velocity and acceleration curves are described as well. The simulation results show that the theoretical analysis is correct. Finally, singularity and its workspace are discussed respectively.关键词：Parallel robotic mechanism;Uncoupled;Kinematics analysis;Singular configuration;Workspace
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发布时间：2022-09-25 - 摘要：It is necessary that parallel mechanisms are researched because of the complex and multiple kinematics solution, and it is the research hotspot and the difficulty. The method of combining D-H and graphical visualization is put forward to solve the forward kinematics of 3-PRS parallel mechanism. Firstly, the spherical hinge in parallel mechanisms is equivalent converted, and then the kinematics analysis is carried out by D-H method, the forward kinematics equation is deduced. Secondly, the 16 forward solutions are obtained by iterative method. The 16 visible graphics are intuitively obtained by visual programming, that is, the forward kinematics solution of the parallel mechanism is obtained. In the end, the result shows that one of the obtained graphics is coincident with the actual position and pose for 3-PRS parallel mechanism. This method is valid and correct, and it is also suitable for solving forward kinematics of other types of parallel mechanism.关键词：3-PRS parallel mechanism;D-H method;Numerical method;Graphical visualization;Forward solution
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发布时间：2022-09-25 - 摘要：Aiming at safe stairs climbing and efficient locomotion on the ground for aged or physical disabled people, a planetary wheeled electric powered wheelchair (EPW) is designed and the composition of the wheelchair mechanism, control system scheme and its functional characteristics are introduced in detail. Through establishing the dynamic model of the planetary wheel clusters based on the Lagrange equation, the angle acceleration curves with various given equivalent torques are studied, the stability margin of the EPW is analyzed in detail in the process of a single step climbing which has demonstrated that the anti-tip-over bracket can effectively enhance the stability. The planetary wheeled stair-climbing wheelchair can effectively help those who are in need and meet the actual needs of daily travel and climbing stairs.关键词：Planetary wheel;Electric powered wheelchair;Lagrange equation;Stability margin
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发布时间：2022-09-25 - 摘要：A method for force analysis of RV transmission mechanism is proposed. The force analysis model of input shaft, planetary wheel, cycloidal wheel, needle tooth shell, crank shaft and planetary frame is established. Considering tangential force, radial force and gravity, the force of RV transmission mechanism is completely expressed in vector form. Based on VB.NET，an force analysis program of RV transmission is developed，which can quickly and accurately calculate the real time change of each force under different crank angle.关键词：RV transmission;Planetary transmission;Force analysis;Vector form;Force change;VB.NET
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发布时间：2022-09-25
Design· Calculation
- 摘要：Spalling and pitting are prone to be produced on the tooth surfaces in the meshing process, which seriously affects the stability and reliability of gear meshing. The time-varying meshing stiffness model and six-degree-of-freedom model of gear meshing are established, the Matlab wavelet toolbox is used to generate an adaptive wavelet which is similar to the original signal. The time frequency characteristic change rule of vibration signal is illustrated. Agreement between the results of the dynamic model and the experimental results validates the effectiveness of the generated adaptive wavelet method which is used to analyze the spalling defect. The results provide theoretical basis and practical support for the gear defect size identification in black-box condition.关键词：Gear;Spalling defect;Adaptive wavelet;Identification analysis
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发布时间：2022-09-25 - 摘要：For the problem that it is difficult to extract fault features of vibration signals of transmission shaft system and the actual situation that it is difficult to obtain a large number of fault samples in fault diagnosis，a fault diagnosis method for transmission shafting based on variational mode decomposition（VMD）sand particle swarm optimization support vector machine （PSO-SVM）is proposed. Firstly, the vibration signal of transmission shaft system is subjected to VMD decomposition, and intrinsic mode function IMF is obtained. Then, the energy value of IMF and the corresponding energy entropy are calculated. Finally, Particle swarm optimization（PSO） is used to optimize the parameters of support vector machine（SVM）, and the energy value and energy entropy of normalized IMF are input into the PSO-SVM to identify the working state and fault type of transmission shaft system. The experimental results show that the accuracy of the method is 94.44%, and it can diagnose the fault of transmission shaft system accurately and effectively.关键词：Transmission shaft system;Fault diagnosis;VMD;Energy entropy;PSO-SVM
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发布时间：2022-09-25 - 摘要：The deceleration process generally exists in the feed system of CNC machine, and the speed change of the process has a great influence on the dynamic performance of angular contact ball bearing, which has always been little noticed by scholars at home and abroad. Taking angular contact ball bearing 7603025 as investigation object, a dynamics analysis model of multi-rigid-body for angular contact ball bearing is established. Based on Adams software, the influence of radial force, axial force and angular acceleration on its dynamic characteristics in the deceleration process is analyzed, which are the speed and centroid trajectory of cage, and the contact force between rolling ball and cage. The study results show that the increase of radial force, the decrease of axial force and the increase of angular acceleration will lead to the increase of collision force between rolling ball and cage, which leads to the skidding in bearings and the shaking of cage more seriously, and the fluctuation range of cage rotational speed curve larger.关键词：Angular contact ball bearing;Cage;Dynamics;Deceleration process
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发布时间：2022-09-25 - 摘要：In the case of strong noise, Ensemble local mean decomposition (ELMD) is proposed for the modal aliasing phenomenon of local mean decomposition（LMD）. However, the white noise added in ELMD cannot be completely neutralized, which will result in the reconstruction error increases due to the Product functions（PF）components to be affected by the added white noise. Therefore, a compound fault feature extraction method for gearbox based on PE-CELMD(Permutation Entropy-Complementary Ensemble local mean decomposition) is proposed. The idea is to optimize ELMD by adding pairwise white noise in combination with Permutation Entropy (PE) method based on ELMD. The method is applied to the simulated signal and the measured signal, and compared with LMD and CELMD, the results show that the PE-CELMD method is an effective compound fault feature extraction method.关键词：Local mean decomposition;Permutation entropy;Compound fault
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发布时间：2022-09-25 - 摘要：The diaphragm coupling has used making up for the micro displacement and angular deviation between input and output terminals by elastic deformation of its geometric shape, the loading effects caused by centrifugal force, axial deformation and torque is supported and transferred effectively, it is mainly used in the field of high precision and high parameters, such as aero and gas turbine. The computational discrete model of the coupling structure of diaphragm and sun-gear shaft is established for strength analysis. Based on strength theory of rotating machinery, the static strength and fatigue strength of sun-gear shaft is analyzed with conditions of single load and multi-coupling loads, two kinds of evaluation criteria of fatigue strength are used for checking. Result shows that strength of sun-gear shaft is meet the requirements under single or multi-coupling loads within the range of working parameters. There is a nonlinear relationship between speed and stress, the great stress is appeared at the alveolar roots, its proportion of stress occupied increases alternately with coupling load. While the high-speed rotating machinery is designed future, structure stress caused by centrifugal and Coriolis force should be considered to ensure the rationality and applicability of structure design. The structure design is safe and has a large of safety margin under uniaxial and multi-axial fatigue strength criteria. The maximum shear stress is appeared at the round angle transition region of shaft shoulder, the maximum stress value of node is 137.3 MPa.关键词：Sun-gear shaft;Diaphragm;Coupling;Fatigue strength
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发布时间：2022-09-25 - 摘要：The slideway restrained conveyor chain is a new type of chain drive configuration. Reasonable selection of various parameters is conducive to improving the performance of the chain. The conveyor chain of a specific case is taken as the research object, and the variation law of the real-time angular velocity of the driven sprocket is calculated. The size of the polygon effect can be expressed by the displacement difference, and the range of the optimal initial phase angle can be found. The simulation results show that the polygon effect of the chain can be reduced by changing the initial phase angle of the main driven sprocket to increase its stability, which provides a certain design basis for the design of the slideway-constrained chain conveyor system.关键词：Slideway constraint;Chain drive;Polygonal effect;Phase angle
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发布时间：2022-09-25 - 摘要：In order to make the best obstacle performance of the crawler deformable robot, and to ensure that the crawler length does not change and continue to tension during the change process, the ellipse theorem and the elliptical rule principle are applied to the robot configuration design, and a new type of crawler deformable robot is developed. The introduction of the rear swing arm enriches the configuration change of the robot, and the center of gravity of the robot has a large degree of adjustment during the rotation of the front and rear swing arms, the obstacle performance of the robot is improved. Mathematical models of typical obstacles such as ramps, steps and gullies are established. The gait planning and motion mechanism analysis of robot overcoming obstacles are established. The kinematics and dynamics models of robot obstacles are established, and the critical conditions for robots to overcome various obstacles are analyzed. The limit value is simulated by Adams to overcome the obstacles, and the accuracy of the theoretical calculation value and the obstacle performance of the robot are verified.关键词：Crawler deformable robot;Double pendulum arms variable configuration;Ellipse theorem;Structural parameter;Obstacle performance
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发布时间：2022-09-25
Test·Analysis
- 摘要：Gearbox fault diagnosis has problems in early feature extraction of non-stationary weak fault signals, vulnerability to strong background noise, and low accuracy of fault diagnosis. A gearbox fault diagnosis method based on Variational Mode Decomposition（VMD）and Deep Support Vector Machine(DSVM) is proposed. Firstly, the original vibration signal is decomposed into several frequency scale Intrinsic Mode Function (IMF) components by VMD, and the IMF component is selected according to the maximum kurtosis criterion to reconstruct the signal. Secondly, the multi-layer support vector is constructed. The SVM is used to train the training sample on the input layer, and it learns the shallow features of the data. The feature extraction formula is used to generate a new expression of the sample, which is used as input of the hidden layer. The hidden layer of the SVM trains on the new sample, and it extracts and learns the deep features of the signal layer by layer, eventually, it outputs the diagnostic results on the output layer. The effectiveness of the proposed method is verified by the gearbox fault diagnosis experiment.关键词：Fault diagnosis;VMD;Kurtosis;Deep support vector machine;Gearbox
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发布时间：2022-09-25 - 摘要：The design and analysis of the refueling switch gear reducer mechanism are carried out. Within the design conditions and design requirements comprehensively considered, the modeling,statics analysis and acceleration impact dynamic load simulation analysis are carried out.The results show that the designed gear reducer meets the design requirements and design conditions,and the maximum strain,maximum deformation and maximum instantaneous impact stress are less than the allowable value.Besides, the accuracy of the finite element model is verified by the real object, and all functions could be realized through the test without interference,which fully meet the design requirements.关键词：Refueling switch;Double motor redundancy drive;Acceleration impact dynamic load;Design and analysis
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发布时间：2022-09-25 - 摘要：The matching valve mechanism drive chain drive system is used to drive the matching valve mechanism of the engine, so that the engine intake and exhaust valves timely open and close, its selection results directly affecting the engine dynamic performance. The maximum working tension of a diesel engine chain is calculated theoretically on the basis of giving the relevant parameters of a diesel engine, and the primary selection of the chain is completed. Then, a matching valve mechanism driving chain transmission system is established in FEV software to input the required parameters in the early stage of simulation, and the maximum working tension of the chain is obtained through simulation. Then finish the chain final selection through the comparison of the two. The research results show that the selection method of the chain is reliable, it has been successfully applied in the selection of chain production enterprises.关键词：Chain selection;FEV software;Simulation;Chain tension
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发布时间：2022-09-25 - 摘要：Focusing on planetary gear fault of traditional NGW type wind turbine gearbox， the fault analysis in the process of using is carried out， finding out why the planetary gear is damaged and an improved design of transmission structure for wind turbine gearbox is presented．The structure, design requirements, load sharing measures and performance characteristics of NW type planetary transmission with internal gear rotation adopted in the improved design are described. The operation practice shows that the improved design of wind power gearbox has the characteristics of high bearing capacity， low noise，high reliability， high transmission efficiency and good maintainability．关键词：Wind turbine gearbox;Planetary transmission;Fault analysis;Improved design
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发布时间：2022-09-25 - 摘要：According to the phenomenon of the external meshing herringbone teeth test of fan drive gearbox, based on the knowledge of dynamics analysis and failure theory, a set of method for purifying and filtering axis trajectory is established. The failure type is determined by comparing the variation trend of the purified filter axis trajectory diagram and the vibration data. The problem can be detected earlier and serious accidents can be avoided by the purified filter axis trajectory.关键词：External meshing herringbone teeth;Dynamics analysis;Failure theory;Purified filter;Axis trajectory
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发布时间：2022-09-25
Development·Application
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