最新刊期
期 11 ， 2018
- 摘要：The meshing characteristics of parallel axis line gear including sliding rate,contact ratio,meshing contact model and meshing frequency are studied,comparing to the inherent characteristics of spur gear that covers the node impact,the dynamic transmission error and the meshing impact. The theoretical analysis results show that the parallel axis line gear can fundamentally eliminate the influences of node impact and timevarying stiffness on the vibration and noise of gear transmission. At the same time,the meshing impact frequency of the line gear is low. The simulation results show that the sliding ratio of the parallel axis line gear is equal to zero,and it has the characteristics of steady engagement. A theoretical basis for the vibration and noise research of the parallel axis line gear and its application is provided.关键词：Parallel axis line gear;Meshing characteristic;Node impact;Time-varying stiffness;Shock absorption and noise reduction;Contact stress
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发布时间：2022-10-20 - 摘要：The machining accuracy of cycloidal tooth surface is the key factor affecting the motion performance of RV reducer,and the reverse correction of grinding parameters according to the data of tooth surface error detection is an important link in the manufacturing process of the cycloidal gear. Through the analysis of the cycloidal gear generating grinding principle,the complex motion relationship between the grinding wheel and the cycloidal gear is clarified and the model of the movement relation of the cycloidal tooth surface is established.Besides,based on the gear meshing theory and the principle of space coordinate conversion,the mathematical expression of the cycloidal gear theoretical tooth surface and the normal vector with the parameters of the grinding adjustment are deduced,which provides a theoretical basis for correcting the tooth profile error after testing.Then according to the cycloidal generating grinding model,the influence of main grinding parameters on the tooth surface error is discussed. Finally,a comparison is made with the cycloidal tooth profile obtained by generation principle,which proves that the equation and its establishment method is correct. It can not only provide the necessary theoretical data for the machining error detection of the cycloidal gear,but also have important significance for the correction of the grinding parameters and the accuracy improvement of the cycloidal tooth surface.关键词：RV reducer;Cycloidal gear;Generating grinding model;Reverse correction;Influencing factor
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发布时间：2022-10-20 - 摘要：The clutch engagement control is a main factor which influences the power interruption time and shock during mode transformation of hybrid electric vehicles. The key is how to be adaptive to the abrasion in the course of usage and change of working condition. For this purpose,an online adaptive optimal control method based on data-driven and torque estimation is presented. The clutch model is updated online by Artificial Neural Network and clutch torque is estimated by Kalman Filtering in real time to solve clutch parametric dynamic uncertainty. Then an object function is formulated to reduce impact and shorten engagement time integrally,combined with a combination optimization algorithm to obtain the optimal outlet valve duty ratio sequence and optimal engagement time. Meanwhile,clutch speed synchronization is accomplished by engine target speed trajectory tracking control. Test results show that the proposed method can be applied on-board in real time and can restrain impact and decrease engagement time effectively in comparison to other control methods.关键词：Clutch;Hybrid electric vehicle;Impact degree;Data-driven;Adaptive control
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发布时间：2022-10-20 - 摘要：In the precision machining process of high precision RV reducer cycloid gear tooth surface,the grinding wheel is included in the tooth groove,and most of the grinding can be converted into thermal energy,causing the temperature of grinding zone to rise sharply. The high grinding temperature will cause secondary tempering burn,white layer and other thermal damage on the surface of the tooth surface. In order to control and prevent the occurrence of thermal damage,the temperature field distribution of tooth surface is simulated by using different grinding process parameters under wet grinding conditions. The heat distribution ratio and convection heat dissipation coefficient of the grinding process are calculated by using the theoretical analysis,and the temperature field distribution of the tooth surface under wet grinding is simulated by means of finite element method and computer simulation software. The results show that the depth of grinding（ ap） has a great influence on the distribution of temperature field. The convective heat transfer of coolant can effectively reduce the temperature of the tooth surface in time,and the finishing environment of cycloid gear tooth surface should be under wet grinding condition. When other grinding process parameters are unchanged,with the increase of grinding depth,the cooling effect of grinding fluid will slow the temperature rise gradient of the tooth surface. The simulation results are of great value in predicting the temperature distribution of the cycloidal gear tooth surface under wet grinding conditions and the reasonable selection of the parameters of wet grinding teeth.关键词：Cycloid gear;Wet grinding;Coolant;Finite element simulation;Grinding teeth burn
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发布时间：2022-10-20 - 摘要：In order to investigate the meshing force of the tooth surface of the plastic helical gear and the steel worm in the transmission process,the mechanical model of the meshing pair of plastic helical gear and steel worm is established by considering the load distribution between the meshing teeth. By using the deformation compatibility in the gear meshing process,the variation of the contact point meshing force of the tooth surface of the plastic helical gear in the continuous meshing process is calculated. And the meshing force of the plastic helical gear and the steel worm is analyzed with the ANSYS Workbench finite element software. The calculation examples show that the results obtained by the method are in good agreement with the simulation results of the finite element method,which proves that the proposed method is reasonable and effective. The research shows that the maximum meshing force of plastic helical gears in the normal meshing process appears in the small tooth meshing area near the tooth root,so the plastic helical gears are prone to wear and fatigue damage.The fast calculation of meshing force between plastic helical gear and steel worm is realized by the proposed method,some references for gear design and gear loading capacity improved in engineering can be provided.关键词：Plastic helical gear;Steel worm;Load distribution;Deformation compatibility;Finite element simulation
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发布时间：2022-10-20 - 摘要：In order to explore the dynamic characteristics of planetary gear transmission system after a failure,combining with the Hertz contact theory and gears excitation,the planetary gear transmission system model in consideration of the contact characteristics of the tooth surface is established. And three tooth-breaking fault factors are introduced into the model,including the planetary wheel,ring gear,and sun gear. The working process of the transmission system under different fault factors are respectively simulated the and its dynamic characteristics are studied by analyzing the dynamic loading spectrum and floating trajectory. Come to conclusion,when the tooth-breaking fault occurs on the planetary gear and the sun wheel,the fault cycle is shorter and has bigger effect on the system than that occurs on the inner gear ring. There is correspondence between the fault frequency and frequency of amplitude of low frequency area in the spectrum. The tooth-breaking fault of the sun wheel makes the radius of center floating trajectory of the sun wheel center to increase greatly. The research on the influence of the fault factors on the dynamic characteristics of the system provides a theoretical evidence for the fault diagnosis of the planetary gear transmission system.关键词：Planetary gear;Dynamic characteristic;Tooth-breaking fault
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发布时间：2022-10-20 - 摘要：In the vehicle driveline system of the automatic mechanical transmission,the engagement quality of the clutch directly affects launching,shifting and the ride comfort,especially the launch quality of the vehicle. According to the basic rule of controlling the clutch in the process of launching and shifting,the control requirements for launching and shifting in automatic mechanical transmission through analysis the dynamics of the vehicle driveline system to determine three characteristics of the engaging force trajectory,following the trajectory characteristics defined six kinds of engaging force trajectories when engaging the clutch. In order to meet the requirements of clutch engagement quality when launching the vehicle,a new clutch force trajectory is determined through the comparative analysis of the influence of six kinds of engaging force trajectory on clutch engagement quality. And according to the evaluation index of the engaging quality of the clutch,a new force trajectory can be achieved by improving the structure of the clutch actuator and controlling the torque variation and the growth rate. The simulation results show that the determined new force trajectory can effectively improve the engaging quality of the clutch so as to achieve the purpose of improving the launching and shifting quality of the vehicle.关键词：Vehicle;Full-electric AMT;Clutch;Engagement force trajectory;Engagement quality
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发布时间：2022-10-20 - 摘要：In order to research the influence of real contact ratio on meshing stiffness and gear dynamic response,the gear meshing assembly model is constructed via the 3 D modeling software SolidWorks,and the model is put into the transient module of FEA software ANSYS Workbench directly,the meshing stiffness under different work conditions is calculated by the Quasi-static method,the influence of real contact ratio on meshing stiffness is studied. Then,under two group operating conditions,the numerical simulations of gear dynamics model with real and theoretical contact ratio is completed respectively by MATLAB,the difference of dynamics response of gear pairs with real and theoretical contact ratio is found. The research shows,during the gear meshing dynamics analysis,the determination of real contact ratio according to special operating condition should be considered,so that obtain a precise analysis resolution.关键词：Contact ratio;Finite element;Meshing stiffness;Gear dynamics;Quasi static
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发布时间：2022-10-20 - 摘要：In order to use the dispersion of the battery in sub-box to establish a low voltage driving system,the conception of split winding motor is proposed,the theory of split winding and the method of winding split are elaborated in the example of a fractional slot concentrated BLDCM. Through the simulation analysis of the virtual fractional slot concentrated BLDCM,the practicability of the split winding motor is preliminarily confirmed. It’ s also found that when the torque-speed characteristic is consistent no matter the winding is split or not,the sum voltage of all the sub-winding is higher than the voltage before the winding is split.关键词：Low voltage driving system;BLDCM;Split winding;Torque-speed characteristic;Simulation analysis
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发布时间：2022-10-20 - 摘要：A method for solving the forward kinematics analysis of parallel mechanism based on BP neural network is presented. According to the algorithm of BP neural network,three layers forward neural network is adopted. The inverse kinematics solution of the mechanism can be obtained by establishing the rotation matrix of3-CRS/SP parallel mechanism. It can be used as input of neural network and the dynamic platform position including four parameters can be regard as the output,then neural network can be trained. The simulation and experimental results show that the method is fast and effective for solving the parallel mechanism forward kinematics,and it is intuitive and simple compared with the analytical method. It can provide numerical reference for the control process of parallel mechanism.关键词：BP neural network;Parallel mechanism;Forward kinematics solution
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发布时间：2022-10-20 - 摘要：A new kind of parallel bionic mechanical legs is put forward. The dimension synthesis and optimization about the mechanical leg structure is completed. The position vector model of the mechanical legs is established. The leg position inverse solution and velocity mapping equation are deduced,the velocity Jacobian matrix is obtained. The space evaluation indexes and movement dexterity indexes of the mechanical leg are established. By using space model technology,the influence laws of the structure parameter on the working space evaluation indexes and motion dexterity indexes of the mechanical leg are analyzed. Combining with the technology of processing and assembling,the multiple target probability parameter optimization method based on performance map is applied to select a set of reasonable structural parameters,which lays a solid foundation for statics and dynamics analysis,stiffness analysis,trajectory planning and motion control of the bionic mechanical leg.关键词：Parallel bionic mechanical leg;Dimensional analysis;Parameter optimization;Space model technology;Performance map
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发布时间：2022-10-20 - 摘要：At present,microsurgery is applied widely in cells and smaller units of gene tissue surgery,but its limitation lies in the lack of excellent micromanipulation equipment. Therefore,a hybrid robot mechanism for micromanipulation with three translation and two rotation of five degrees of freedom （DOF） is presented. Firstly,the mobility and motion feature of this 5-DOF mechanism is analyzed with the constraint screw method.Then the inverse and forward displacement problems of the proposed hybrid mechanism are solved according to the geometrical relationship,and the Jacobian matrix of the mechanism is obtained based on the forward and inverse solution,the decoupled feature of the proposed parallel mechanism is validated. Finally,the kinematics models of the mechanism are established,the virtual prototype model of the mechanism is established and simulated by Matlab,the linear displacements and angular velocities output image of the mechanism are obtained,the correctness of the theoretical analysis is verified and established,the theoretical foundation for its further applications is provided.关键词：Micromanipulation;Five degree-of-freedom;Robot mechanism;Kinematics
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发布时间：2022-10-20 - 摘要：The calculation method of equivalent load for crane reducer under variable load condition is analyzed. Application factor formulas for the calculation of gear fatigue strength and bearing fatigue life are deduced,and the index value of the fatigue strength calculation of gear is recalculated based on the life coefficient. In addition,the differences of load spectral coefficients in gear and bearing fatigue calculations are pointed out. The calculation method has a guiding significance for the design and calculation of crane reducer.关键词：Crane reducer;Fatigue strength;Fatigue life;Equivalent load;Application factor
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发布时间：2022-10-20 - 摘要：To solve the problem of the contact ellipse in the geometric contact simulation of gear teeth which needs the numerical approximation of the quadratic approximation of the tooth surface and the complicated curvature derivation,the method of contact ellipse calculation based on numerical iteration is proposed. Firstly,the instantaneous contact point is solved by meshing basic equations,then the whole week search is conducted according to the given elastic deformation starting from the point,the instantaneous contact ellipse and the long and short axes of the contact position are obtained,and then the whole tooth surface contact prints are got.Finally,taking a pair of cycloidal gear hypoid gears as an example,the feasibility of this method is verified by comparison with commercial software and rolling inspection results.关键词：Numerical iteration;Instantaneous contact ellipse;Contact impression;Cycloid hypoid gear
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发布时间：2022-10-20 - 摘要：The planetary wheel hub reducer has large transmission ratio,compact structure and strong carrying capacity. Based on the structural characteristics of the secondary planetary wheel hub reducer,the number of teeth,modulus and tooth width are used as design variables under the condition of keeping the total gear ratio unchanged. Under the condition of the same input power and rotational speed,and root bending strength reaches a certain safety factor,the optimal variables are sought to minimize the overall power loss. Based on Simulink,the model of the optimal solution of the wheel-rim reducer is built and imported into Labview. The real-time simulation of the model is carried out in Labview and PXI environment and its dynamic characteristics are analyzed. The result shows,after optimization,the system power loss rate is reduced from 3. 87% to 3. 31%. The meshing deformation of gear transmission at each stage of rear wheel reducer is chaotic,the meshing deformation of gear pair is determined by the torque transmitted,and the time-dependent stiffness of gear meshing fluctuates around the stable value,which shows that the optimal design is reliable.关键词：Wheel hub reducer;Power;Transmission ratio;Gear;Model
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发布时间：2022-10-20 - 摘要：Gear modification is an important technique to improve its transmission performance. The herringbone gears are combined with star gear transmissions to form a herringbone star gear transmission,and its modeling method of modified tooth surface as well as computing method of loaded transmission error are researched. With the target of the minimum amplitude of loaded transmission error,the gear modifications are optimized for the sun-star meshing gear pair and the star-ring meshing gear pair respectively. The modifications from optimization are redistributed,and the rationality of the redistribution is verified by the means of TCA and LTCA techniques. The research results provides a theoretical basis for the modification design of a star gear train.关键词：Herringbone gear;Star gear transmission;Modification;Tooth contact analysis;Loaded transmission error
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发布时间：2022-10-20 - 摘要：In order to achieve man-machine collaboration more closely and determine a reasonable and accurate model of upper limb movement,according to the anatomical structure of upper limb,a design eightsection upper limb exoskeleton rehabilitation robot is proposed. Based on the usual upper limb robot to make improvements,according to the complex structure of the upper limb to establish accurate equivalent kinematic model to achieve the robot and the internal structure of the shoulder joint alter accordance,and can alleviate the treatment of discomfort effectively. Then the reachable workspace of upper limb motion is simulated accurately.The simple inverse kinematics algorithm is used to solve each variable of joint. According to the characteristics of the human body,the rehabilitation trajectory planning is selected by the method of double-quaternion in task space and verified by SolidWorks,MATLAB and V-REP software. The rationality and feasibility of the design and algorithm is proved.关键词：Exoskeleton mechanism;Precise model;Kinematics;Simulation
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发布时间：2022-10-20 - 摘要：In order to improve the braking torque of the traditional magnetorheological brake with double coils placed on side housing,a novel magnetorheological brake with double coils ripple is proposed. The novel structure enabled it to have larger area of controllable shear face by adding semicircular grooves and ridges on the end surfaces of conventional magnetorheological brake with double coils placed on side housing. The center position of the semicircular grooves and ridges is determined by mathematical method,the torque model of the novel magnetorheological brake is derived. The results show that when the novel magnetorheological brake adopting the way of semicircular groove in the rear of ridge,and the number of semicircular grooves or ridges is two,the novel magnetorheological brake can obtained the maximum torque of 184. 6 N·m. Compared with traditional magnetorheological brake with double coils placed on side housing,the braking torque of the novel cycloid curved magnetorheological brake is increased by about 46%. The results can be taken as reference to the design of magnetorheological brake.关键词：Magnetorheological brake;Braking torque;Semicircular groove;Semicircular ridge
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发布时间：2022-10-20 - 摘要：Introducing the combination of multi-dimension spring elements as the equivalent of elastic bearings and gearbox,an equivalent model of gear drive system coupled with elastic supports is proposed,with the coupling relationships between the shaft-bearing-gearbox supports and between the bearing holes of gearbox expressed as the displacement constraint equations of elastic supports. Combining with the FE contact analysis model of gear set,an analysis method of transmission performance is established. Taking a single-stage helical gear train as an instance,the influence of the supporting forms and rigidity on transmission performance indexes,including transmission error and the contact stress distribution on tooth surfaces,is analyzed by using this method. The analysis results indicate the method reflects the influence of supporting rigidity characteristics on transmission performance more veritably and comprehensively than empirical formulas. A guidance for the rigidity design of supports is provided.关键词：Elastic supports;Equivalent;Coupling relationship;FE contact analysis of gear;Transmission error
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发布时间：2022-10-20 - 摘要：The influence factors of static shift performance and dynamic shift performance of manual transmission are analyzed. Because of requirements of gear shift performance test,the mechanical system and software system of transmission shift performance test rig are designed. Based on the developed test bench,static shift performance and dynamic shift performance test of a transmission are carried out. The static shift test shows that the designed test system can accurately measure performance parameters of transmission shift mechanism,such as track selection,gear clearance and select stiffness. The dynamic shift performance test shows that the designed test rig can measure performance parameters of shift force,lever travel and transmission input speed,and it can detected whether there are double bump in the shift process.关键词：Manual transmission;Test system;Shift performance;Test research
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发布时间：2022-10-20 - 摘要：It is difficult to determine the gear churning power loss directly by theoretical methods because gear churning power loss has a complex relationship with its influencing factors. Because of the pumping effect of gear meshing,there is a certain difference between single gear churning and meshing gears churning. However,the existing formulas for calculating the churning power loss are mostly aimed at single gear churning power loss and its application is very limited. The CFD software FLUENT is used to simulate the gear churning during the no-load of a pair of meshing gears. The calculation results are compared with the experimental results. The influence of gear rotation direction and gear ratio on the gear churning power loss is analyzed. The difference of the oil loss between spur gear and helical gear is also compared. The results show that the simulation results are close to those of the test results and the simulation method can accurately predict the power loss of the gear meshing gear. The gear rotation direction,gear ratio and helix angle have great effects on the churning power loss of the gear pair.关键词：Meshing gear;Churning power loss;Fluid dynamics;Experimental verification
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发布时间：2022-10-20 - 摘要：Taking the standard planetary roller screw mechanism for aircraft electro mechanical actuator as the research object,the analytical solution is obtained by calculating the mechanical properties of the fiber,using ANSYS Workbench software for finite element simulation analysis,and the analytical solution is compared with the simulation results,the maximum deviation value of the two is not more than 5%. On this basis,the influence of lead of screw （lead angle） on screw life is analyzed. The results show that with the increase of lead of screw （lead angle）,the life of screw pair gradually increases. It shows that proper increase lead of screw （lead angle）,can improve the life of screw pair. At the same time,the influence of roller root number on the life of screw pair is analyzed. With the increase of roller root number,total contact points increased,and the life of the screw pair will gradually increase. From the point of increasing the life of the screw pair,the more of roller root number is,the better. This research provides the basis for the optimization design and analysis of the planetary roller screw mechanism with high reliability and long life.关键词：Standard planetary roller screw mechanism;Life;Lead of screw;Lead angle;Roller number
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发布时间：2022-10-20 - 摘要：A kind of Hindley worm and cylindrical helical gear is presented. According to the geometrical parameters of Hindley worm,the geometric parameters of the helical gear with the Hindley worm is calculated,a three-dimensional model of Hindley worm and cylindrical helical gear is established. The statics analysis is carried out by using the finite element Workbench software,the tooth surface contact stress,equivalent stress and displacement are obtained. The tooth profile and helical double direction concave are modified for helical gear. The results show that the concave modification can reduce the contact stress and displacement of the tooth surface properly,so as to improve the bearing capacity of gear pair. The effect of tooth profile modification on contact performance is more significant. The feasibility of the proposed straight Hindley worm and helical gear transmission is verified by processing and rolling test.关键词：Hindley worm;Cylindrical helical gear;Tooth surface modification;Finite element analsis
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发布时间：2022-10-20 - 摘要：In order to realize the purpose of vibration control and energy-regenerative,take some wheel type vehicle as object,an Electromagnetic actuator（ EA） of gear and rack type is designed,the relative math model is built and the analysis of the influence of inertia force and its character of damping is conducted. For the purpose of verifying whether the EA satisfies the design demands,the principle prototype is machined,and the experiment test of its character of mechanical friction,electromagnetic damping,active force and feedback voltage are conducted. The result indicates that the maximum mechanical friction force is 285 N,which satisfy the demand of design restrict. Under the restrain of rated current,the maximum electromagnetic damping force is about 1 100 N,which means a good damping adjust ability. The maximum active force is close to 1 000 N,a bit less than theoretical value,the maximum feedback voltage is about 80 V,during the optimal energy-regenerative interval of suspension relative velocity of 0. 1 ～ 0. 3 m/s,energy-regenerative power is close to hundred Watt of whole vehicle,which is proved possess good ability of energy-regenerative. The EA satisfy the design demand,and the structure scheme is feasible.关键词：Energy-regenerative;Character test;Electromagnetic damping;Electromagnetic actuator
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发布时间：2022-10-20 - 摘要：The Empirical Mode Decomposition （EMD）,as an empirical method,lacks rigorous theoretical proof. For this reason,EMD in practical application is confronted by many problems,which make EMD hard to extract fault features from vibration data of complex wind-turbine gearboxes. The Fourier decomposition method （FDM） is a novel method for processing non-stationary and nonlinear signals. With a firm theoretical basis,FDM has the capability for overcoming deficiencies of EMD. The FDM is used to analyze vibration data of wind-turbine gearboxes and a method for fault diagnosis of wind-turbine gearboxes based on FDM is proposed. Application to fault diagnosis of a realistic wind-turbine gearbox shows that the proposed method can effectively diagnose faults of wind-turbine gearboxes and has a clear advantage over the method based on each of spectrum analysis,EMD and wavelet decomposition.关键词：Fourier decomposition method （FDM）;Empirical mode decomposition （EMD）;Windturbine gearbox;Fault diagnosis
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发布时间：2022-10-20 - 摘要：The rocker arm of underground shearer is the core equipment of coal mining machinery. The transmission system of rocker arm machine has the characteristics of heavy load,and the gear transmission system is difficult to lubricate,its working reliability has an important influence on the coal mining safety and the economic benefit of coal mining. Therefore,through the typical parts failure analysis of gear breaking and pitting corrosion of the transmission gears,bearing wear and gluing,and the physical characteristics test analysis of lubricating oil,the fault mechanism for the transmission system of rocker arm machine is studied. The results show that the physical properties of the selected lubricating oil have an important influence on the transmission system. Due to improper selection and maintenance of lubricating oil,the viscosity of the lubricating oil can not meet the lubrication requirements,which leads to the over-heating of the transmission system,bearing failure and partial overloading of the gear,even tooth pitting and partial broken teeth occurs,and further leads to the failure of the rocker gear transmission system. The research work provides a valuable reference for designing,using and maintaining of heavy-duty gear transmission systems.关键词：Shearer rocker arm;Gear transmission system;Failure mechanism;Lubricating oil
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发布时间：2022-10-20 - 摘要：A complex gear transmission system is one of the core components of a tracked vehicle. In order to study the dynamic characteristics of the gear transmission system under different operating conditions,considers the working characteristics of the torque converter and the time-varying contact force of the meshing gear pair,by using the software platforms Creo and RecurDyn,a virtual prototype simulation model of a complex transmission system is established. The model is simulated under the condition of 1-gear hydraulic pressure. The variation rules of speed and torque during starting process are analyzed. The steady-state value of speed is validated by the test values. At the same time,the time-frequency curve of contact force between gears is extracted and analyzed. The simulation process and the results provide the model and technical support for the research of the condition monitoring and fault diagnosis of the gear transmission system.关键词：Gear transmission system;Virtual prototype;Dynamic characteristic;Recurdyn
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发布时间：2022-10-20 - 摘要：The three-dimensional parametric models of RV reducer are constructed by using SolidWorks software,and then the model is imported into ADAMS software,a batch of dynamic models are established and simulated by macro program,and the exporting data of rotation speed and rotation angle is imported into Matlab.After data processing,the transmission error and the fluctuation of rotation speed that is the variance of the rotation speed are calculated. The simulation result shows that under the condition of the variation of error value is the same,decreasing the radius of gear pin and increasing the value of modification of positive equidistance,the value of fluctuation of rotation speed will increase greatly,increasing the value of the modification of negative moved distance and modification of negative equidistance, it will decrease less. For transmission error,decreasing the radius of gear pin and increasing the value of the value of modification of positive equidistance,it will increase greatly,increasing the value of the eccentricity of pin wheel has tiny influence on it.关键词：RV reducer;Macro program;Transmission error;Fluctuation of rotation speed
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发布时间：2022-10-20 - 摘要：The training data of an intelligent gear fault diagnosis model usually comes from vibration experiments which run at specific speeds,when the actual running speed of the gear transmission system is not consistent with these vibration experiments,the diagnosis model may be invalidated. The vibration mechanism analysis of gear transmission system shows that,the vibration response signal of a gear transmission system contains interference components that vary greatly with the speed and cannot reflect the fault information,the fault characteristics in amplitude spectrum of the vibration response signal have less sensitivity to the variation of running speed. These interference components can be removed with the help of prior-knowledge which is composed of structure parameters,operating parameters and the vibration mechanism of gear transmission system. Using the amplitude spectrum of the vibration response signal whose interference components are removed as input of the diagnosis model,it can reduce the feature difference between the samples of same class which correspond to different running speeds,and improve the generalization ability of the diagnosis model effectively,so that it can adapt to speed variation in a certain extent.关键词：Gear faults;Intelligent diagnosis;Prior-knowledge;Speed variation;Amplitude spectrum
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发布时间：2022-10-20 - 摘要：The honing stone profile shift coefficient will become negative by fixed axis cross angle when dressing honing stone,which change the gear honing contact condition and cutting parameters. Firstly,the gear surface structure formation mechanism and the causes of honing stone profile shift by fixed axis cross angle are analyzed. Then,a variable axis cross angle technology strategy of honing stone dressing is puts forward,which can guarantee the gear surface honing structure constant. It can be described that the axis cross angle is a function of center distance when honing stone dressing and gear honing. Finally,the simulation shows that the technology can obtain constant contact and cutting parameters between workpiece and honing stone during its life,and the surface structure of the gear will not change. At the same time,it can ensure that honing stone profile remains constant in its life,and the number of dressing times of honing wheel is greatly increased.关键词：Internal gear honing stone;Honing stone dressing;Variable axis cross angle;Surface structure
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发布时间：2022-10-20 - 摘要：Taking a 9 speed automatic transmission （9 AT） of ZF company as study object,it is composed of four planetary gearsets and 6 shift elements. The transmission line of 9 speed automatic transmission is analyzed. The motion equation of each planetary gearset is established. The constraint conditions are built by using the action sequence of shift element. By simultaneous motion equations,the transmission ratio formula of each gear is calculated. The correctness of the formula is verified with the distribution of the transmission ratio of each gearset.关键词：9 speed automatic transmission;Planetary gear;Motion equation;Transmission ratio
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发布时间：2022-10-20 - 摘要：In order to study the comprehensive performance of shift tower in the manual transmission,a performance test system for the shift tower is designed. The test system adopts the selection and shift motor to drive the shift tower to realize the operating function of the gear selection and shift. According to the measurement and control requirements of the test system,the hardware and software of the measurement and control system are designed. Finally,taking the test system as the test platform,the performance test of the selection force-displacement characteristic and shift force-displacement characteristic of a certain shift mechanism are carried out. The test results show that the test system can really-time and accurately measure the performance parameters such as selection force,selection displacement,shift force and shift displacement,which provides experimental support for the research and development of the shift tower.关键词：Shift tower;Test system;Measurement and control system;Performance test
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发布时间：2022-10-20 - 摘要：Taking sweeping robot as the research object,solving the requirement of climbing higher steps and automatically adapting to different step heights in the process of robot running. An adaptive auxiliary obstacle climbing mechanism is designed,which is connected with the main driving wheel of the machine and is triggered by connecting rod mechanism when the step is touched to increase the additional driving force. The whole process of obstacle crossing is modeled by Euler dynamic equation. Combined with the application of the product in the actual family environment,the formula for calculating the torque of the key design parameters is given after excluding the distracters. Finally,the practical data of the mainstream products in the market are calculated,and the feasibility and application value of the auxiliary mechanism on the specific products are verified.关键词：Floor sweeping robot;Adaptive;Auxiliary obstacle surmounting
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发布时间：2022-10-20 - 摘要：With the two kinds of analysis methods of classification analysis and theoretical mechanical analysis,the runaway fault of the large flat-headed tower crane rotation is systematically analyzed,the possible reasons that could cause the tower crane rotation out of control are explained in detail,and the countermeasures of avoiding runaway fault and guaranteeing the tower crane safety are provided for its design,manufacture and its users.关键词：Large flat-headed tower crane;Rotating mechanism;Driving device;Rotary support;Rotary resistance torque;Driving torque;Electronic control equipment runaway
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发布时间：2022-10-20 - 摘要：For successful calculating undercut radius from hobbed machining of involute spur gear with small tooth number. Firstly,the application scope of the conventional calculation method is analyzed by two examples. Secondly,because of the special feature of gear hobbed machining with small tooth number,the tangent continuity condition of gear profile on undercut point must be neglected,and from center transposed angle of arc blade of undercut point,an developed method for calculating undercut radius is derived. Finally,all parameterized tooth profile equations of the gear is created. All results indicated that the conventional calculation method is applicable only the condition of upper radius coefficient limit determined by rack cutter geometry greater than its lower limit determined by successful gear hobbed machining,unfortunately,for the involute spur gear with small tooth number,its upper limit usually is less than its lower limit,so the conventional calculation method isn’t applicable for calculating undercut radius. The center transposed angle of arc blade really is greater than the pressure angle with 20° of straight blade,the hobbed machining is successful from optimized normative radius coefficient of arc blade for the gear with small tooth number. The created 3D gear model is reliability and fully parameterized,etc. It is concluded that the developed calculation method as an theoretical basis is provided for other followed calculating of involute spur gear with small tooth number.关键词：Small tooth number;Involute spur gear;Undercut radius;Hobbed machining
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发布时间：2022-10-20
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