最新刊期
期 12 ， 2015
- 摘要：Aiming at the cycloidal gear used in RV reducer of robots,based on the concept of the single tooth without side clearance,the tooth surface equation of the cycloidal gear after modification is deduced by directly adding the second- order parabolic modification amount to the theoretical conjugate tooth profile along the normal direction. The modification amount of different meshing position on tooth profile curve could be flexibly controlled by controlling the tooth profile modification coefficient. The differences between the parabolic modification and the traditional modification method of the combination of isometric and travel distance,the proposed parabolic modification method is much closer to the complete conjugate tooth profile on the main meshing areas.The TCA program of cycloidal- pinwheel transmission which is written in Matlab formed parabolic transmission errors and the correctness of this modification is proved,which provides a new thought for the modification design of cycloidal gear used in RV reducer.关键词：RV reducer;Cycloidal gear;Modification;Tooth surface equation;TCA
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发布时间：2022-10-20 - 摘要：The precision grinding technology of face gear is a key difficulty to its further development. According to study the characteristics of the special grinding generative movement of face gear,the numerical analysis of face gear grinding process is studied based on the software of ABAQUS and taking the residual stress as parameter index. The reliability of grinding simulation is determined through the analysis of simulation process.According to the results of the orthogonal analysis and rule explores,the influence law of the grinding velocity,feed velocity,cutting depth and grain size on the residual stress is obtained. The targeted results have high reliability,and the theoretical basis of grinding wheel selection and grinding parameters chosen for face gear grinding is established.关键词：Face gear;Grinding;Residual stress;Orthogonal analysis
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发布时间：2022-10-20 - 摘要：In order to improve the power performance and fuel economy of the electric vehicle,the transmission ratio optimization design for a two- speed electric vehicle transmission system is studied. The 0 80km / h acceleration time and hundred kilometers power consumption are respectively taken as two sub- objective functions for dynamics and economic performance. A speed ratio optimization model for the dual objective functions is built. Taking the coupling effect of the shift schedule in optimization process into account,the rule of developing a comprehensive shift strategy,which associates with ratios and considers the dynamic and economic performances is determined. An enumeration algorithm,which has the function of non- dominated comparing and filtering,is designed to obtain the Pareto- optimal solution set for the dual objective function. Finally the proposed electric vehicle with a set of the optimal ratio solutions is compared with this vehicle with the initial ratios. The results show that the acceleration time is shortened by 3. 5% and the energy consumption is decreased by 2. 4%,the power performance and fuel economy of the electric vehicle are improved.关键词：Electric vehicle;Two-speed transmission;Shift schedule;Ratio optimization
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发布时间：2022-10-20 - 摘要：A three- degree- of- freedom shaft- torsion coupling nonlinear dynamics model of a single-stage helical cylindrical gear transmission system is established,which included the nonlinear factors such as gear backlash,time- varying stiffness,transmission error and so on. A gear backlash function suitable for the helical cylindrical gear system is obtained by high order fitting the piecewise linear gear backlash function using in the spur cylindrical gear system. The results of the nonlinear dynamic response under two different gear backlash functions are obtained by employing the established dynamics equation of helical cylindrical gear system with variable step- size Runge- kutta method numerical solution. The influences of frequency on the bifurcation and chaotic characteristics under two different gear backlash functions are analyzed by using bifurcation diagrams,top Lyapunov exponent（ TLE） diagrams,phase portraits,Poincaré maps and FFT spectrums. The gear backlash function obtained by high degree fitting is more suitable for helical gear system by analyzing and comparing.
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发布时间：2022-10-20 - 摘要：According to the principles of various gear profile generation and gear generating error,the motion control structure of NC hobbing system for gear machining is optimized. The electronic composite differential unit is used to process the angle position pulse from the hobbing spindle and to process the motion coordinate（ or angle position） pulse from the workpiece axis. By means of position control and error compensation control unit,the on- line real time compensation of errors as tooh pitch division error,longitudinal tooth error,and tool wear error is realized. Meanwhile,the hobbing function of non- circular gear and axial modification gear（ small taper or drum type） is also expended.关键词：Error compensation;Electronic composite differential;Kinematic error;Eccentric motion
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发布时间：2022-10-20 - 摘要：By analyzing the characteristics of structures for the lower- mobility serial robot mechanism and parallel robot mechanism,a systematic and effective type synthesis including the definition and symbol denotation method of both hybrid robot with a parallel mechanism and multi- parallel mechanisms method is proposed for hybrid robot mechanisms based on the principle of movement spiral linear independence and units of the lower- mobility serial mechanism with single- opened- chain limb. Firstly,type synthesis of 3T2 R 5- DOF serial mechanism with single- opened- chain is classified based on the screw theory,then the type synthesis of 3T2 R hybrid mechanisms are accomplished by regarding parallel mechanism as a complex kinematic unit and replacing an equal DOF kinematic chain limb in lower- mobility serial mechanism with single- opened- chain limb. Finally,other type synthesizes for other type synthesizes of 3T2 R hybrid mechanism are generated by the linear combination of the kinematics screw.关键词：Single-opened-chain;Screw theory;Serial mechanism;Hybrid robot mechanism
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发布时间：2022-10-20 - 摘要：In order to solve the problem of the poor dynamic response characteristics of new type mechanical CVT under non- steady working condition,a new type mechanical CVT is regarded as the research object,the principle and the working state of CVT are analyzed to obtain CVT transmission ratio variation under non-steady working condition,and the CVT fuzzy PID transmission ratio control system is established,finally,the new- type mechanical CVT non- steady PID control system feasibility is validated. The results show that non-steady state transmission ratio controls CVT output torque and transmission ratio in the non- steady state transmission control can guarantee a smaller overshoot and within a relatively short time reach a stable value.关键词：Mechanical CVT;Non-steady;Transmission ratio;Control
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发布时间：2022-10-20 - 摘要：Considering the dynamics model parameter uncertainty and external disturbance of four-wheeled omnidirectional mobile robot,a kind of four- wheeled omnidirectional mobile robot trajectory tracking control method based on adaptive sliding mode is put forward in order to improve the trajectory tracking control performance. Firstly,the robot dynamics model is established on the basis of drive motor parameters. And an adaptive sliding mode trajectory tracking controller is designed. At the same time a parameter adaptive control algorithm is proposed in order to achieve the online estimation of the robot dynamics parameters,and real- time switch gain adjustment of trajectory tracking controller is achieved by using RBF neural network as to reduce the chattering of the system. Finally,the simulation experiment is carried out by using MATLAB in order to verify the effectiveness of the described method. The simulation results show that the four- wheeled omnidirectional mobile robot trajectory tracking method based on adaptive sliding mode control can well reduce the effects of parameter variations and external disturbances on the system. It can reduce the chattering of the system and has good anti- interference ability.
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发布时间：2022-10-20 - 摘要：In order to solve the problems of short service life and higher thermal deformation of heavy duty vehicle oil cooling disc brake,an oil cooling disc brake is regarded as research subjects,the thermo- mechanical coupling analysis model of oil cooling disc brake is established in brake condition,finally,the influences of the brake disc thickness and cooling oil flow rate on brake friction disc contact surface,the internal stress field,temperature field distribution are got. The results show that the oil cooling disc brake highest temperature and maximum braking stress can meet the use requirements of materials in continuous braking condition. With the increase of the thickness of the brake disc,the brake temperature and stress values show a downward trend.With the increase of oil flow rate,the highest temperature and maximum stress of brake also show a downward trend,and oil cooling disc brake stress value become stable in the oil flow rate of 4 m3/ h.关键词：Heavy duty vehicle;Oil cooling;Disc brake;Temperature;Stress
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发布时间：2022-10-20 - 摘要：In order to solve the problems of higher friction temperature and short clutch life of hybrid vehicle wet multi- plate clutch,a hybrid vehicle wet multi- plate clutch is regarded as research subjects,the transient heat transfer model of wet clutch is established in engagement condition,the wet clutch friction plate radial rectangle groove width is set to analysis variables,the influences of the radial rectangle groove width on friction plate transient temperature field are got. The results show that with the increase of friction plate radial rectangle oil groove width,the wet clutch highest temperature will show a downward trend,but the friction plate temperature and friction plate geometry features exist greater relevance in the angle range,and present the characteristics of a certain period. The influences of radial rectangular oil groove width on the temperature field of wet clutch are investigated,it provides a direction to get the best rectangle oil groove width by optimization design method.关键词：Hybrid vehicle;Wet multi-plate clutch;Groove width;Temperature
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发布时间：2022-10-20 - 摘要：The planetary carrier is an important transmission mechanism in tracked vehicles side gear reducer,and it is designed with the static strength theory within the limitation of test and experimental method.Thus the actual dynamic characteristics of planetary carrier cannot be embodied,and it brings difficulty to predict life with given dynamic loads and results in wide gap between actual life and designed. The virtual running test platform is built based on ADAMS. ATV,and the dynamic load suffered by planetary carrier in different working condition is obtained. Then the fatigue life of planetary carrier is obtained with the fatigue life prediction model of planetary carrier established with MSC. Fatigue. The study case proves the new method is feasible to predict fatigue life of planetary carrier,and the fatigue life prediction for tracked vehicles component under complex operating conditions are explored. The study results can widely extended to other engineering domains,and it has very important practical significance.关键词：Tracked vehicle;Driving simulation;Planetary carrier;Fatigue life prediction
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发布时间：2022-10-20 - 摘要：Based on the study of relation of mesh deflection of spur gear,three key elements of tooth modification,transmission error and its frequency spectrum,the three principles of tooth modification design are defined for good transmission to get lower vibration excitation. And the modification optimizing and design method are analyzed for heavy load,light load and for both load cases.
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发布时间：2022-10-20 - 摘要：The transmission gear rattle noise as a common noise of the mechanical transmission,which occurred on the meshing and unloaded gears,is mainly induced by the fluctuation of the engine output torque and the backlash gap. The generated mechanism of rattle is studied based on the impact,the multi- body dynamic equations of a pair of gear rattle is established,and the influence of rigid collision and elastic collision on gear rattle is analyzed and compared. To analysis the input speed and gear selection on transmission rattle,a multi- body dynamics model of gear system for a mechanical transmission is built by CATIA and ADAMS.关键词：Transmission noise;Gear rattle;Impact;Adams simulation
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发布时间：2022-10-20 - 摘要：To realize the controllable of the motion state of double generating- wave swing- rod movable tooth drive,the reverse design of wave generator tooth profile is carried out by using the complex number vector method based on the given motion law of the swing- rod. The tooth profile equation of wave generator is built,and the tooth profile equation of central wheel is deduced in detail based on converted gear train and envelope principle to get the same form theoretical tooth profile equations of wave generator and central wheel. The change law of central wheel curvature radius is illustrated based on the same mathematical model analysis,the non- interference conditions of equidistant teeth profile are given. The effect of structure parameters for the minimum profile curvature radius during the process of designing is analyzed and the principle of choosing the parameters is formulated. The change law of the velocity of swing rod movable teeth is analyzed during the transmission process. The results of the design example contribute to the series design and parametric design of double generating- wave swing- rod movable tooth drive while the operating condition is given.关键词：Double generating-wave;Swing-rod movable tooth drive;Tooth profile equation;Curvature radius
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发布时间：2022-10-20 - 摘要：The crank- group driving mechanism is a kind of under- actuated mechanism with redundant characteristics,aiming at the characteristics of mechanism,selecting continuous contact model for the joint clearance,the dynamics model of the basic structural unit- double crank mechanism with clearance is set up by the second kind Lagrange equation. Then,assume that the inertia force direction of no quality rod pointing to truss connecting rod,the derivation from the unit to the whole is carried out,and the dynamics model of the crank- group driving mechanism with clearance is established.关键词：Crank-group driving mechanism;Dynamics model;Clearance
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发布时间：2022-10-20 - 摘要：The research of the cam- gear combination mechanism,according to the given trajectory,the design is divided into two parts reverse solution cam meshing track and cam outline. Based on the cam meshing track reverse solution with SOLIDWORKS software and the MOTION plug- in,through the EXCEL software for data processing,the ideal cam outline is acquired and making the mechanism can realize given trajectory,the correctness of the design is verified by forward simulation. This solution method is concise and accurate,the tedious computation is eliminated,it is suitable for engineering people.关键词：Combination mechanism;Cam mechanism;Reverse design;Appropriate closure trajectory
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发布时间：2022-10-20 - 摘要：Because of the widely applications of robots,the labor productivity is greatly enhanced and the working environment is improved. The kinematics analysis of manipulator is a basis for achieving accurate motion control. The kinematics of a kind of 6- DOF collapsible manipulator is studied,the forward and inverse kinematics within the scope of joint angles is obtained according to the geometric characteristics of robot,by using the MATLAB,the verification of kinematics simulation is carried out.关键词：Manipulator;Inverse kinematics;Matlab
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发布时间：2022-10-20 - 摘要：The carbon- free car is a kind of car with direction control function,the gravitational potential energy drive. In order to solve the manufacturing error,assembly error affect carbon- free car trajectory problem of inaccurate,through the car trajectory mathematical analysis,the trajectory equation is established. By using Mathematica software,the car trajectory simulation experiments is carried out. Then the sources of error and error forms affect the trajectory changes are analyzed and summarized. Based on this trajectory analysis and the design method of introducing the micrometer and worm gear mechanism into the fine- tune mechanism is proposed,a fine- tuning mechanism and fine- tuning method with higher adjust precision than ever are obtained. Through physical prototype testing,good results is achieved by fine- tuning program in the trajectory modification,a new way of thinking for carbon- free car fine- tuning mechanism design is provided.关键词：Carbon-free car;Trajectory analysis;Mathematica;Fine-tuning mechanism
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发布时间：2022-10-20 - 摘要：In order to enhance the bearing capacity,the double generating angle tooth profile for the oval gear pair used in unidirectional and continuous transmission occasion is designed. Based on the generation cutting theory,the pure rolling mathematical model that the center line of double pressure angle asymmetrical rack roll along the oval pitch curve is deduced. The secondary development technology of three- dimensional software is used to realize the digital modeling of oval gear pair,and then the kinematics and mechanical analysis are conducted. As a result,the designed double meshing angle oval gear pair can meet the transmission requirement and have good mechanical ability,which has well reference to the bearing capacity improvement of other non- circular gear pair.关键词：Oval gear;Double meshing angle;Generating method;Simulation
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发布时间：2022-10-20 - 摘要：A method of reverse design of conjugate cam is introduced. By using Pro / E with the contour surface data of CAM,the 3- D model is built and kinematics simulation analysis is carried out,the displacement,velocity and acceleration curves of the following mechanism are got before the reverse. Then,by using the polynomial law of motion to fit the original one after getting the parameters with the motion curves after dimensionless processing. Finally,comparing the kinematics simulation after the reverse with the former one. The transmission accuracy and work efficiency of cam are proved to be greatly improved through the simulation and trial- manufacture.关键词：Conjugate cam mechanism;Reverse design;Polynomial fitting
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发布时间：2022-10-20 - 摘要：A double roller type planetary gear drive with small tooth number difference is designed,and its meshing surface is composed by two array cylinder rollers,which is equidistributed in the internal gear and external planetary gear. The transmission principle and characteristic is analyzed,the determination and optimization method of the design parameters is discussed. According to its characteristic of discontinuous transmission,the transmission error is calculated and analyzed based on the error calculation formula. The research results reveal that this drive completely meets the error requirement of the power transmission and also has the possibility to be used in precision transmission with the optimal design.关键词：Double rollers;Planetary gear drive with small tooth number difference;Optimal design;Transmission error
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发布时间：2022-10-20 - 摘要：In order to solve the problems of large design margin and high manufacturing cost of traditional heavy duty vehicle drum brake,the new type hydraulic wedge type brake is regarded as research subjects,the calculation formulas of wedge brake torque,brake drum surface average temperature,maximum temperature are got,the design of the model is optimized through the simulated annealing algorithm,finally,the optimization model is validated through the finite element calculation and experiment. The results show that the stress value of hydraulic wedge brake after the optimization of the key components can meet the material requirement of use,the hydraulic wedge brake after the optimization in different brake pressure and initial speed of braking conditions braking efficiency is with high stability.关键词：Hydraulic wedge brake;Optimal design;Simulated annealing algorithm;Experiment
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发布时间：2022-10-20 - 摘要：The kinematics and rigid- body dynamics theoretically analysis and the ADAMS simulations of the NGW type planet differential mechanism are carried out. The kinematics analysis show the results that the mechanism can realize the velocity synthesis and differential operation with different speed of two input shafts.Through the rigid- body dynamics analysis,the results as following. Firstly,the relations among the two input angular accelerations,two input torques,the interaction forces between the planet carrier and the planetary gear,the meshing forces at a tangent between gears in case of acceleration and deceleration are derived. Secondly,the relation between the two input axes angular accelerations and two input torques and one load torque is derived. Thirdly,the relation between load torque and the two input torques and two input axes angular accelerations is derived. Fourthly,the force amplitudes between the sun gear and its planetary gears are equal to each other. Fifthly,the force amplitudes between the internal gear ring and its planetary gears are equal to each other. Lastly,the interrelation relationships of the angular accelerations are matched with kinematics relationships.The simulation results by ADAMS are consistent with theoretical consequences. The theoretical analysis is proved to be correct. The results can be applied to performance analysis of the differential mechanism in redundant electromechanical servo actuation systems in case of acceleration and deceleration.关键词：NGW type planet differential mechanism;Kinematics;Rigid body dynamics;Adams simulation
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发布时间：2022-10-20 - 摘要：The design of neutron spectrometer sample,which is developed by our country is briefly introduced. Based on Hertz contact theory and the structural features of telescopic electric cylinder used in the neutron spectrometer,the theoretical model of telescopic electric cylinder drive rigidity is established and the numerical calculation is carried out. The load- drive rigidity curve is obtained by calculating rigidity under different axial loads. The impact factor is defined to analyze the degree of the weight of each deformation of transmission stiffness,and the impact factor of deformation of different parts are calculated and analyzed to find the weak links of the rigidity. Some measures are taken to improve the rigidity,the basis for accuracy of telescopic electric cylinders is provided. Finally,the finite element model is analyzed by using ANSYS Workbench,the analysis results with the theoretical value is an error of 8. 1%,the correctness of theoretical analysis is verified.关键词：Neutron spectrometer;Telescopic electric cylinder;Drive rigidity
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发布时间：2022-10-20 - 摘要：Based on the displacement coupling relationship and loading equilibrium relationship between rolling bearings and rotor,a dynamics model of rolling bearings- rotor system based on the internal load- bearing deformation coordination condition is established. A pair of 276927NK1W1（ H） angular contact ball bearings in symmetry in the single- rotor system are used as the example,the influence of rotor coupling on vibration of angular contact ball bearings is analyzed,and the influence rule of working conditions of bearings on rotor coupling effect are future studied. The results could afford more accurately reference for failure analysis of high speed ball bearings.关键词：Rotor-rolling bearing coupling;Angular contact ball bearing;Contact stress;Sliding ratio
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发布时间：2022-10-20 - 摘要：Aiming at the problems of multi- scale morphological difference filter,a new fault feature extraction method of rolling bearing based on multi- scale morphological difference filter and singular difference spectrum is proposed,which could effectively filter out the noise and extract the fault details. With the help of the theory of feature energy ratio,two different kinds of multi- scale weighted method is proposed in the multi- scale morphological difference filter,and the results of multi- scale morphological difference filter in different biggest analysis scales are studied. Then,by using the singular difference spectrum,put the result of morphological filter which failed to effectively filter the Gaussian noise into SVD reconstruction,and the final feature extraction result is got. The simulation shows the method could effectively extract the pulse shock signal under the high noise background,and in the fault feature extraction of actual bearing fault signals is also.关键词：Multi-scale;Morphological difference filter;Feature energy ratio;Singular value decomposition（SVD）;Difference spectrum
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发布时间：2022-10-20 - 摘要：The new calculation methods for the maximum radial deviation of sun pinion in operating and the minimal length of a toothed coupling are given. And the maximum radial deviation of sun pinion in operating are consisted of four parts: the total radial composite deviation of sun pinion plus the total radial composite deviation of planetary gear,the half of the maximum radial clearance of planetary gear bearings,the maximum deviation of the center distance for planetary gear with the sun pinion,and the deviation under loads. It is recommended,that a reasonable limit for angular misalignment in a single articulated coupling is 0. 001 radians. It is confirmed,that these methods and the recommended value are right,reasonable and reality in a various of practical applications.关键词：Planetary gear;Toothed coupling;A reasonable limit for angular misalignment;Radial deviation of sun pinion;Minimal length of toothed coupling
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发布时间：2022-10-20 - 摘要：For the motor performance demanding disadvantage in tracked vehicle bilateral independent motor drive scheme,a power coupling scheme is proposed. By analyzing the performance characteristic and speed,torque mathematical transformation model of the coupling mechanism,the feasibility of coupling scheme is demonstrated. Explains most of the power coupling mechanism can turn the power back through mechanical means by dynamics calculation,and the power requirements of the tracked vehicle steering can be significantly reduced. The analysis results verify the correctness and feasibility of the scheme,and a new idea for the electric drive tracked vehicle scheme selection is provided.关键词：Electric drive;Coupling scheme;Renewable power steering;Power utilization ratio
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发布时间：2022-10-20 - 摘要：Based on the dynamics theory of rolling bearing,the dynamics model and nonlinear dynamics differential equations of the cylindrical roller bearing during the start up are obtained by considering of the change of lubrication state between rollers and rings. The simulation analysis for the effect of radial loads,accelerations of the inner ring,viscosity of lubricating oil and working temperatures on the slippage characteristics of roller are carried out by solving the equations. The results show,during the start up of the cylindrical roller bearing,the rotational speed growth of the roller about its axis is not linear but stepwise,and there exists a more serious slippage in the early start. The slippage ratio of roller varies heavily with radial loads or accelerations of inner ring. A proper increase in viscosity of lubricating oil or an appropriate decrease in working temperature can reduce the slippage of roller to prevent the raceway scratch effectually during the start up,and effect extent of working temperature is smaller than viscosity of lubricating oil.关键词：Cylindrical roller bearing;Start up;Dynamics analysis model;Slippage characteristic of roller
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发布时间：2022-10-20 - 摘要：The pre expansion quantity of the spring directly affects the dynamic and static performance of spring clutch. On the basis of establishing the spring clutch dynamics finite element model,the dynamic engagement characteristic of spring under the different condition of pre expansion quantity is analyzed,the response time,radial displacement and inner ring joint time and spring Mises stress and compressive stress are obtained. The results indicate that spring and shell cannot stable engaging when have no pre expansion quantity,and it would lead to invalidation. In a stable engagement condition,the engagement and response time is in milliseconds. Increasing the pre expansion quantity,the spring radial displacement increases,the average compressive stress of spring along the length direction would decrease,and the distribution of compressive stress becomes more uniform.关键词：Spring clutch;Pre expansion quantity;Dynamics;Finite element method
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发布时间：2022-10-20 - 摘要：A new approach for mechanical fault diagnosis based on local characteristic- scale decomposition（ LCD） information entropy feature and support vector machine（ SVM） is proposed. Firstly,the fault mechanical vibration signal is decomposed by using the LCD to obtain a certain number of intrinsic scale component（ ISC）. Secondly,combined with information entropy theory,the singular spectrum entropy in time domain,power spectrum entropy in frequency domain,feature space entropy,marginal spectrum entropy and momentary energy entropy in time- frequency domain are defined and used as the feature vector. At last,the feature vectors are put into SVM classifier to recognize different fault type. The results of experiment of bearing fault diagnosis demonstrate that the method based on LCD information entropy feature and SVM is able to identify the bearing faults accurately and effectively,and the diagnosis effect is better than the method based on empirical mode decomposition（ EMD） information entropy and SVM.关键词：Local characteristic-scale decomposition（LCD）;Information entropy;Support vector machine（SVM）;Feature extraction;Fault diagnosis
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发布时间：2022-10-20 - 摘要：Based on the viscoelasticity driving belt of transverse vibration equations under the action of parametric excitation,by using the method of multiple scales,the approximate solution of the 1 /2 subharmonic- primary parametric resonance equations is obtained. The influence of the viscoelasticity parameter,detuning parameter and an axial moving speed on the amplitudes of steady- state response boundaries is analyzed. Some new dynamical phenomena are revealed of viscoelasticity driving belt.
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发布时间：2022-10-20 - 摘要：To the problems of high inheritance and high parameter uncertainty of dump truck drive axle housing in conceptual design process,the space narrowing methodology and interval propagation theorem are introduced into the conceptual design process,the axle housing main parameters scope of the design space are further narrowed,finally,the range of design solution main parameters meet the changing needs of the performance is found and the stress,deformation and life of dump truck drive axle housing concept design model are verified by finite element method. The results show that,through space narrowing theory and interval propagation theorem,the concept design of dump truck drive axle housing change interval of main parameters is significantly reduced,the method can eliminate the uncertain information of initial design space,and the rationality of the optimization result is verified by finite element method.关键词：Drive axle housing;Space narrowing methodology;Dump truck;Conceptual design
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发布时间：2022-10-20 - 摘要：Based on the analysis of S curve control method,aiming at the robot acceleration and deceleration time is too long and severe vibration in the process of start,stop,resulting in the motion precision problem of robot,a 5 order S curve with time optimal and the smallest impact is proposed. Under the premise that ensure the robot motion constant,with the least amount of acceleration and deceleration time and smooth movement as the optimization index,the improvement of 5 order S curve design is carried out. Finally,the simulation verification of improved S curve is carried out,the simulation results show that,for the conventional 5 order curve,the optimized 5 order S curve acceleration and deceleration time is shortened,and the acceleration curve is more smooth.关键词：S curve;Acceleration and deceleration;Time optimal;Simulation
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发布时间：2022-10-20 - 摘要：In order to solve the problems of long stroke mechanical joint brake system difficulty in design,manufacturing and repair costs are high,a new wet brake in long stroke mechanical joint brake system is introduced,and the expressions of key design index of new braking system is derived,finally,the experiment platform for the research of the variation law of braking characteristics of a new wet type long stroke mechanical joint brake system is built. The results show that the new joint brake in the initial stage of braking has certain drag torque phenomenon in single braking condition. The new joint brake increased significantly at the initial stage of braking torque in continuous braking condition,with the increase of number of brake,brake torque variation tends to be stable. When the braking times of the number of 0 600 times,the brake temperature increased rapidly,when the braking times reach 1200,the brake temperature reaches thermal equilibrium. The new wet type mechanical joint brake system torque fluctuation in two kinds of braking conditions rate all meet the design requirements,the design scheme is feasible.关键词：Wet type;Mechanical joint;Brake;Design;Experiment
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发布时间：2022-10-20 - 摘要：Hydro- mechanical continuously variable transmission is a kind of power- split stepless transmission device,which realizes the stepless speed regulation by hydraulic regulating speed mechanism and the higher efficient by mechanical variable speed mechanism. The five simple and reliable stepless transmission device is designed autonomously,through the different combinations of hydraulic regulating speed mechanism and mechanical variable speed mechanism,the switch of hydraulic transmission,hydro- mechanical transmission and mechanical transmission is carried out to meet the requirements of smooth start,field operation and transportation,the power performance and fuel economy performance of diesel engine are given full play,and the transmission performance and efficiency of transmission are improved greatly. In order to reach the goal of energy conservation and emissions reduction,a simple introduction of energy storage device is given.关键词：Hydro-mechanical continuously variable transmission;Stepless speed regulation;Transmission mechanism;Designing scheme
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发布时间：2022-10-20 - 摘要：From tooth profile wear and the demand of match manufacturing,a set of field mapping method is proposed,which does not depend drawings,while by virtue of toothed parameter with accumulated manufacturing experience that included addendum circle,tooth root circle,helix angle,variable coefficient measuring,modulus and pressure angle determining. At the same time,two examples of the successful application for measuring are cited. It concludes that modulus of wear gear can be accurately calculated based on the mean value of length difference for cross- tooth normal line,pressure angle can be determined based on the theory of alveolar bottom size,and the addendum helix angle can be estimated by the auxiliary template,thus the helix angle of helical gear is deduced. According to tooth root diameter,modulus,tooth number and helix angle,the modification coefficient is calculated finally. The mapping method can be used to guide the repair and pairing manufacture.关键词：Gear;Modulus;Pressure angle;Helix angle;Modification coefficient;Measurement
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发布时间：2022-10-20 - 摘要：Through the fracture analysis of the failure gear,finding the gear tooth broke belongs to fatigue fracture,by checking designing,assembly,material heat treatment and quality,it could be found that the insufficiency of shot peening coverage is the main reason of gear break. For this reason,according to shot peening technology specification SAE AMS- S- 13165,the shot peening again is carried out to remedy the shortage shot peening coverage,the gear strength is obviously improved,and the gear fracture is solved in bench duration test.关键词：Bench test;Shot peening;Gear tooth break;Coverage ratio
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发布时间：2022-10-20 - 摘要：Aiming at the requirement of the efficient move on the ground and safe stairs- climbing for some physical disabled or aged people,a new wheel- track hybrid electric powered wheelchair（ EPW） is designed. The technology solution of the wheel- track hybrid EPW is proposed and its mechanical structure and control system are designed. The process of climbing up and down the stairs in the track mobile mode is analyzed and diagrammatized. The prototype of this wheel- track hybrid EPW is manufactured and the experiments of climbing up and down the stairs are implemented. The experimental results show that the designed wheel-track hybrid EPW can realize the function of both moving on the ground efficiently and climbing up and down the stairs safely.关键词：Electric powered wheelchair;Stairs-climbing;Wheel-track hybrid;Structure design;Mechanical model
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- 468
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发布时间：2022-10-20 - 摘要：In order to solve the problems of the poor driving stability of vehicle sectional type driving axle housing,associate with the reliability and response surface theory,a kind of hybrid uncertain parameters of the vehicle stability analysis method for sectional type drive axle housing is put forward,in this method,after the parameterization of the sectional type drive axle housing model,the analysis and the study of the vehicle sectional type driving axle housing of system stability,reliability and global sensitivity are carried out. The research results show that by reducing the brake pressure and friction coefficient have an important significance to improve the system stability of sectional type driving axle housing.关键词：Sectional type;Driving axle housing;Stability;Reliability;Uncertain parameter
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发布时间：2022-10-20 - 摘要：Due to the computational complexity of grinding wheel profile and grinding interference in the process of grinding double circular tooth gear,a form grinding method is proposed. The gear tooth profile and tooth surface equations of the double circular tooth gear are obtained based on the principle of gear engagement.On this basis,the solution of form grinding contact condition and grinding wheel profile of double circular tooth are carried out. The method is verified by VERICUT simulation and form grinding experiment respectively. The results show that the proposed method can solve the technical problem of the double circular tooth gear by form grinding method.关键词：Form grinding;Double circular tooth gear;Grinding wheel profile;Simulation and experiment
- 2
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发布时间：2022-10-20 -
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