最新刊期
期 7 ， 2015
- 摘要：The planetary roller screw mechanism（ PRSM） has high load carrying capacity,high transmission accuracy and high reliability in harsh environment. Because of those advantages,the PRSM is used in a variety of industry applications. The study of PRSM mainly focus on matching of the design parameters,kinematics analysis,static stiffness calculation,friction moment and efficiency calculation and processing methods.Few papers have found to investigate the meshing theory of PRSM. The meshing characteristics of PRSM are described by concerning its mechanical structures. Based on review of the existing researches on the meshing theory of PRSM,some suggestions are presented for future research and developing.
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发布时间：2022-10-20 - 摘要：The profile of the gear in internal helical gear is modified to realize point to point contact. The transmission coordinate system is built to deduce the tooth surface equation,the nonlinear meshing equation is built based on meshing theory. The relative velocity and normal vector of the reference point are calculated,and the numerical solution of nonlinear meshing equations is obtained with newton iteration method. The numerical solution is substituted into the mesh equation to solve the transmission error,tooth contact trace and contact ellipse,consequently realized the mesh simulation of the internal helical gears which tooth surface is carried out.
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发布时间：2022-10-20 - 摘要：In order to increase the reliability and efficiency of the kineto- static analysis of complex space robot systems,the corresponding vector bond graph method is proposed. From the kinematic constraint condition,the vector bond graph models of spherical joint and prismatic joint are built. Based on this,the vector bond graph model of 3PS + 1PS parallel robot is established. For the algebraic difficulties brought by differential causality and nonlinear junction structure in automatic modeling and kineto- static analysis of spatial robot mechanism,the effective bond graph augment method is proposed. By the corresponding algorithm,the automatic modeling and kineto- static analysis of 3PS + 1PS parallel robot system on a computer is realized,its validity is illustrated.
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发布时间：2022-10-20 - 摘要：To overcome the high computational cost of reliability analysis,a reliability analysis method which combines the multidisciplinary genetic algorithm collaborative optimization（ GA- CO） based on the inverse reliability strategy（ IRS） is proposed（ IRS- GA- CO）. The genetic algorithms- based collaborative optimization（ GA- CO） is one of the improved forms of CO that overcomes the difficulty of convergence given the existing of highly nonlinear consistency constraints. The IRS- GA- CO,which not only lifted the coupling between all disciplines to improve the search most probable point,the burden of system- level optimizer also can be significantly reduced. Examples of speed reducer prove the efficiency and precision of the proposed method.What is more,this advantage in the design of large- scale complex engineering systems will be better reflected.
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发布时间：2022-10-20 - 摘要：Based on analyzing the meshing theory of ideal gear and the tooth surface equation,the tooth surface equation of modified cylindrical gear profile with arcuate tooth trace is deduced. The modeling of modified cylindrical gear profile with arcuate tooth trace is realized based on UG. The change curve of contact stress with different modification coefficient is obtained through the comparing and analyzing the contact stress of different modification with help of the ANSYS Workbench（AWE）. The result shows that the value of contact stress decreases with the increase of modification coefficient. When the modification coefficient over 0. 2,the trend of the contact stress decreasing remained unchanged,the theory basis for the design of modified cylindrical gear with arcuate tooth trace is provided by this results.
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发布时间：2022-10-20 - 摘要：The mathematic model of the metal pushed V- belt continuously variable transmission is established,and the influence of CVT speed ratio variation on the vehicle acceleration is analyzed and simulated through the example. The research result proves that the changing rate of the speed ratio affects on the vehicle acceleration to a certain extent. As the result,the changing rate of the speed ratio should be controlled according to the direction of the changing. Through the research,the theoretical foundation and method are provided for the control strategy of the CVT speed ratio changing rate.
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发布时间：2022-10-20 - 摘要：In a flat layer locking- mechanism of SS type construction lift,a spatial RSSR mechanism with variable rod length is developed,it is used to lock the construction lift flat layer by combining planar sine-mechanism. According to adjust the rod length of RSSR mechanism in terms of the cage opening door angles on construction lift,the output component displacement of sine- mechanism remains unchanged under the different opening angles of cage door to realize the reliable work can be guaranteed through the flat layer locking mechanism. The structure of the mechanism is introduced,the motion model of this combined mechanism is built,the relevant design and computation process is provided,an example is taken to illustrate. A reliable reference for developing similar product is provided through the research work.
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发布时间：2022-10-20 - 摘要：A new type of gear bi- directional arc cylindrical gear is proposed,the tooth trace of the gear is arc,the bending resistance strength of the gear can be increased and the axial force of the gear transmission can be eliminated. In the processes of gear transmission meshing,it is convex surface and concave surface contact transmission,the carrying capacity of the gear is increased,the wear of the tooth surface is decreased,the service life of the gear is improved. The gear pair meshing character is researched and its contour curve equation,meshing line equation and transmission ratio are derived. reach A conclusion that the gear pair possess the advantages of constant transmission ratio and stable transmission is obtained.
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发布时间：2022-10-20 - 摘要：The tooth profile of harmonic gear has a significant influence on the harmonic drive device performance,for the purpose to improve the harmonic drive performance,the involute tooth profile of harmonic drive is adopted as the research object,the conjugate tooth profile of harmonic drive is designed based on the envelope theory,and the conjugate exist domain,conjugate tooth profile are analyzed,the simulation analysis of the assembly station and the move locus of the conjugate tooth profile are carried out. The analysis results show that there are two conjugate exist domain and two conjugate tooth profile,however,only the first conjugate domain and the first conjugate tooth profile is effectively,the tooth profile that is designed have many advantages such as nice conjugate situation,much number of tooth profile join in conjugate,highly transmission ratio,it can provide certain reference for design and research of the harmonic drive.
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发布时间：2022-10-20 - 摘要：The theoretical formulas of operating frequency are established based on transmission principle and operation mode of RV reducer by using mechanism transformation method and pure rolling hypothesis of bearing roller,and applied to calculating operating frequency of RV- 40 E reducer. The theoretical calculated results are checked by ADAMS simulation,the maximum error of theoretical values is only 4. 19 percent. The autorotation speed of crank throw bearing roller is very high,increasing the roller diameter of crank throw bearing is an effective way to lower roller autorotation speed and improve bearing life. A general,quick and efficient calculating method for rotational frequency of RV reducer transmission parts and rolling bearing parts is provided.
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发布时间：2022-10-20 - 摘要：In order to reduce the energy dissipation in truck crane moving and rotary stages,improve the saving energy levels of truck crane,taking the energy during braking process and turning process as the system energy recovery object to build the energy recovery system of a new kind of truck crane system energy recovery device with multi- objective. The structure design of the truck crane system energy recovery device,the energy recovery processes and policy are researched,the energy recovery process for each target performance computing is carried out. Finally,the actual verified is carried out through the actual parameter.
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发布时间：2022-10-20 - 摘要：The inverse solution equation set is established according to the mechanism and constrained characteristic of 6- PTRT parallel robot,and the kinematics forward solution equation set is established.Through the further study of the parallel mechanism,the forward solution equations are reduced by six- dimension to three- dimension by using the mechanism own characteristic. The three- dimensional forward solution equations is transformed into solving the optimization problems,and the forward solutions are calculated by using PSO algorithm. The correctness of the mathematical model is verified by comparing between the experimental results and simulation results. This method has the advantages of high efficiency,easy convergence,doesn’t depend on the initial value,and the theoretical basis for the real- time control of 6- PTRT parallel robot is provided.
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发布时间：2022-10-20 - 摘要：Improving the load sharing property of multiple planets is not only one of the effective methods to improve the large megawatt wind turbine gearbox power density,but also is the key to the design of wind turbine gearbox. Taking the latest research and development of 8 megawatt wind offshore wind power gearbox as the research object,and the rigid flexible coupling dynamics model with a gearbox of new configuration and initial parameters is established by using the ADAMS. The real dynamics analysis of functional virtual prototype is carried out to research the bearing property of planet gears and pinions,and then conduct its contained load sharing design. The load sharing of each planetary wheel and pinion is analyzed by fitting data of the extracting gear meshing force simulation data,and take center external gear in ordinary gear train and the internal ring gear in the differential gear train floating as design scheme in order to improve the system load characteristics,the results show that the performance of the load sharing is effectively improved. This study laid the foundation for the detailed structure design of high power density megawatt wind power gearbox.
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发布时间：2022-10-20 - 摘要：A series parallel 7- DOF humanoid mechanical arm is designed and the mathematical model of humanoid mechanical arm is established through integration of kinematics analysis for parallel structure and D-H modeling method. The forward kinematics simulation of humanoid mechanical arm is carried out with Robotics toolbox of MATLAB,and then the continuous and smooth planning curves of joints angel and the Cartesian space trajectory of wrist are obtained. The simulation results show that the design parameters of humanoid mechanical arm are reasonable and can provide the basis for the optimal design of humanoid mechanical arm.
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发布时间：2022-10-20 - 摘要：The mathematical model of the globoidal cam indexing mechanism applied to the rotary concave die of cold heading machine is established. The parameters of the globoidal cam indexing machine are designed and the motion law of globoidal cam is selected based on the operation condition of the cold heading machine.Through detailed cases,the parametric model of globoidal cam indexing mechanism is realized by using the Pro /E and Matlab,the dynamics model of it is developed by using the ADAMS and the motion simulations are carried out. The research shows that,under high- speed condition,the globoidal cam indexing mechanism has the characteristics of stable meshing and the locating accuracy reaches 36″ applied to the cold heading machine.
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发布时间：2022-10-20 - 摘要：The dynamics performance of serpentine belt accessory drive（ SBAD） system is influenced by the tensioner arrangement parameter including tensioner installation position and installation angle. In order to control the vibration of SBDA system,taking the tensioner arrangement parameter as design variable,taking the maximum effectiveness coefficient of the tensioner and the minimum transverse vibration amplitude of belt span as objective,the two optimization models including a multi- objective and a single- objective are established,The optimization of a three pulleys SBAD system is carried out,By comparing the optimization result and counting process between the two optimization schemes,the effectiveness of the single objective optimization method with introducing weight coefficient is point out.
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发布时间：2022-10-20 - 摘要：The gear strength is one of most important part in mechanical design. Several crisis problem will be mainly discussed which often confused and misunderstood about the calculation of the gear strength including the failure mode of gear,bending fatigue strength design,contact fatigue strength design,etc. The development of gear strength design in history and the current situation of it are also referred. This can be referenced for gear and other mechanical design or teaching,beside,it can also help the designer or student to get a deeper comprehensive and a better improvement on gear design and its background.
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发布时间：2022-10-20 - 摘要：The error analysis of the RV reducer transmission is investigated,but the study on general method for the tolerance design of the RV reducer is less in present literature. A new method for the tolerance design of RV reducer- method of weighting is proposed. The mathematical model is established in the first step,the model is related to hysteretic errors and the input designed parameters. The method for determining the sensitivity and dimensions of the weight coefficient is introduced. The RV- 20 E type reducer is designed with this method,it is meet the design requirements both in theoretical analysis and trial tests. This method will have certain guiding significance for the tolerance design of RV reducer.
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发布时间：2022-10-20 - 摘要：Based on the physiological characteristics of crab,a bionic crab- like robot composed of eight legs and two pincers is designed by using bionics principle. The cross direction moving and turning of the bionic crab- like robot are realized by controlling the walk stepping motor to drive gear crank connecting rod mechanism,the lifting and falling of pincers is realized by controlling the lifting stepping motor to drive gear and rack mechanism,the left and right swing of pincers is realized by controlling the swing steering engine,the snatching of pincers is realized by controlling the snatching steering engine drive intermittent gear and double- rocker linkage mechanism. The bionic crab robot has three good merits such as agile transmission,high driving efficiency,convenient maintaining,which is seasoned with different road surface. The robot has a good application potential under complex road conditions to search and detection. The design method is helpful for transmission design of multi- legged bionic robot in execrable environment.
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发布时间：2022-10-20 - 摘要：Aiming at the non- circular gear with closed pitch curve,the characteristics of pitch curves and gear tooth distribution of the non- circular gear are introduced. According to non- circular gear meshing theory and the conversion method of tooth profile,taking the limacon gear as an example,by using the Matlab software,a different eccentric pitch curve of limacon gear is drawn,and its characteristic is analyzed. The three- dimensional solid model is fully drawn,by using the function of three- dimensional solid modeling and some specific drawing instructions. According to the formation tooth profile of limacon gear,the associated features can be analyzed and the foundation of further finite element analysis,the formation of computer simulation tools trace and CNC machining are provided.
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发布时间：2022-10-20 - 摘要：Aiming at the development of the water motor of petrochemical decoking transmission,the method of pitch curve calculation and tooth profile machining of non- circular planetary gear with tooth surface modification is studied. By using the multiobjective optimization theory,the mathematical model to solve the pitch curve of non- circular planetary gear is established,the calculation theory of non- circular gear tooth profile is proposed,the program of solving the pitch curve and tooth profile coordinate calculation is developed based on the software of Matlab. The correctness of the theory and the feasibility of the software are verified through the example calculation and processing and assembling experiment.
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发布时间：2022-10-20 - 摘要：The double circular arc tooth profile of harmonic drive has a significant impact on the performance of gear transmission,based on the kinematics of harmonic gearing theory,the common tangent double circular arc tooth profile that suitable for harmonic drive is designed by using the MATLAB,the meshing simulation analysis of the interference,lateral clearance,deformation,trajectory is carried out. The results show that the design of double circular arc tooth profile harmonic drive is out of meshing when the turn angle of wave generator is greater than 62°,and the number of teeth in meshing is more; before the flexible gear contour out of meshing,the gear tooth without interference,always maintain continuous contact,the mesh point changing,and meshing in good condition,it is help to improving the bearing capacity of the harmonic drive,transmission precision,torsional stiffness and other performance.
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发布时间：2022-10-20 - 摘要：Taking the V belt of transmission device in the coal mine belt conveyor as optimization design object and combining with both optimized design ideas and Matlab,regarding minimal gross weight of V belt pulley as optimization goals,the modeling and optimization of multi row V belt drive is carried out by using exterior penalty method,the parameter is solved out and determined with branch and bound method. Then,the multi row V belt drive kinematics simulation and dynamics simulation are carried out. The results show that,the optimum design not only make the system has compact transmission structure,lightest quality,but also has well motion characteristic and dynamics characteristic,and transfer movement well. The rationality of optimization design is verified,the reference and basis for the optimization design of the belt of transmission device in coal mine belt conveyor are provided.
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发布时间：2022-10-20 - 摘要：The working principle and composition of a certain type of artillery servo angle test system are introduced,the test system of gear transmission chain in the azimuth angle measuring device and the calculation of angle measurement accuracy are analyzed and explained. Through the three- dimensional modeling software UG NX,the three- dimensional model of azimuth angle measuring device is built,and the data interaction with mechanical dynamics simulation software ADAMS is realized,the virtual prototype model is established in ADAMS and the dynamics analysis of virtual model is completed,the speed of input,output shaft of azimuth angle measuring device and the time domain regularity curve of gear meshing force are obtained,the theoretical reference for further studying the characteristic of artillery azimuth angle measuring device gear transmission system is provided.
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发布时间：2022-10-20 - 摘要：Aiming at the current situation of existing vehicle dynamics model does not have the ability to accurate simulate the dynamic process of vehicle shimmy,a vehicle model is developed for simulation of the dynamics process of vehicle self- excited shimmy. Through the overall dynamics modeling of the steering system,the mechanical correlation between left and right steering wheels is established. Through the steering dry friction model,it is accurately describes the static friction characteristics at the steering kingpin. By using the wheel model,the accurately describes of the elastic characteristics of tire is carried out. Through the simulation of typical operating conditions,the ability to accurate simulate the dynamic process of vehicle self- excited shimmy of the model is verified. The simulation research of the key parameters influence on the self- excited type shimmy is carried out,then some measures to avoid shimmy are given.
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发布时间：2022-10-20 - 摘要：The three- dimensional bevel gear is established in Pro / E by using parameterization modeling method. Taking the advantage of Pro / E and ABAQUS dedicated interface,the bevel gear model is imported into ABAQUS and the model analysis is carried out by using ABAQUS. The first six natural frequency and vibration model shape are extracted and compared with web bevel gear. A theoretical basis for dynamic characteristic analysis and gear reducer design are provided.
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发布时间：2022-10-20 - 摘要：Aiming at the automotive drive shaft in the transmission existing inevitably resonance phenomenon during the high- speed operation,the drive shaft is regarded as research object,the vibration modal analysis is carried out and the natural frequency and modal vibration mode are got. The results show that the drive shaft of the finite element simulation results and experimental results are identical with each other,the resonance frequency with 50 Hz power frequency and the frequency of the motor vehicle doesn’t occur in the process of running,the foundation for fault diagnosis of drive shaft,comfort and smoothness of the automobile are provided.
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发布时间：2022-10-20 - 摘要：According to modulation characteristics of rotating machinery fault vibration signals and limitation of the traditional envelope spectrum analysis needs to rely on experience for determining the parameters of band- pass filter,a fault diagnosis method for rotating machinery based on maximum correlated kurtosis deconvolution（ MCKD） and envelope spectrum is proposed. Firstly,by using MCKD,the noise in the rotating machinery vibration signal is reduced,then the envelope spectrum is obtained by Hilbert transform to identify the fault,simulation signal analysis and engineering applications demonstrated the effectiveness of the method.
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发布时间：2022-10-20 - 摘要：The water lubricated stern bearing is a special bearings which widely used in ships and other water vessels sail propulsion system,because of its work environment is of great uncertainty,the product is prone to various of failures,once the failure happens,it will directly affect the ship safe navigation and economic benefits. By using the theory and methods of Matlab software based on neural networks,the BP neural network model is constructed to study the work of stern bearing friction coefficient,temperature,noise,vibration and bearing condition characterized by the relationship between the parameters of the time,in order to achieve fault diagnosis for water lubricated stern bearing operating conditions. From Matlab simulation results with the actual situation,the established BP neural network can be a good judge for failed state water lubricated stern bearing,it can send an early warning signal when the bearing failure,will be issued in advance of cattle bearing failure for repair or replacement. By using this method,can effectively improve the use and safety of water lubricated stern bearing.
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发布时间：2022-10-20 - 摘要：Combining the wavelet transform and approximate entropy theory,according to the characteristic that the approximate entropy will become larger with the increase of signal complexity,it is applied to the analysis of acoustic emission signals of the bearing. In the test,through collecting acoustic emission signals under such working conditions as different stimulated defects,speeds or loads,then,the wavelet packet de- noise and transform is applied to this signals,and the maximum energy subband is found,and the approximate entropy calculation is carried out. Based on the analysis of the signals collected,it is concluded that the approximate entropy will become larger with the increase of radial load and speed in fault bearings while this phenomenon will not appear in the normal bearing. Thus a good diagnosis effect is achieved.
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发布时间：2022-10-20 - 摘要：The disc- type magnetorheological fluid transmission device driven by shape memory alloy under thermal effect is a transmission device that its output speed rapidly changes with the temperature changes.Compared with the clutch working with high temperature,the transmission device extends the service life of the magnetorheological fluid. Aiming at transmission device,the working principle is analyzed,the magnetic circuit theoretical model is established based on Ohm’s law of magnetic circuit. The magnetic circuit theoretical model of transmission device is simulated by ANSYS software and the correctness of the simulation model is verified by the iterative calculation. The influences of different disc material and working gap size along the radial magnetic induction intensity are obtained by simulation of magnetic circuit,moreover the influence of isolation ring to the magnetic field intensity and output torque is analyzed.
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发布时间：2022-10-20 - 摘要：The test bench for constant speed ratio experiment study of cone ring type CVT is developed based on the analysis of the structure principle of cone ring type CVT. Considering the unique structure of cone ring type CVT transmission pair and lubrication conditions,the CVT speed ratio control mechanism and cyclic traction oil temperature automatic control system are designed,and the integrated control of the test bench is realized. Based on the test bench,the durability and efficiency test methods for cone ring constant speed ratio experimental are put forward,and then the constant speed ratio and transmission efficiency experiment of cone ring type CVT transmission pair is carried out. The results show that the cone ring type CVT transmission pair and transmission efficiency perform well,the structure strength passes the verification,the transmission efficiency of each ratio is above 84% and a basis for the further optimization and improvement of cone ring type CVT is provided.
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发布时间：2022-10-20 - 摘要：In order to study the dynamics characteristic of the helical gear,according to the situation of helical gear pair in the process transmission,a 5- degree bending- torsion- shaft coupled dynamics model of single- stage helical gear transmission system is established with time- vary friction force. According to the influence of contact ratio,the meshing time is divided. Based on Buckingham semi- empirical formula,the tooth surface friction coefficient variation with the meshing- point position is obtained. The movement differential equations are discussed by the variable step size Runge- Kutta method. The bifurcation diagrams,Lyapunov exponents,cloud pictures of the maximum amplitude and the amplitude- frequency characteristic superposition graphs are obtained and the system dynamics characteristic variation with frequency is analyzed. The strong resonance and amplitude jump phenomenon are happened under the conditions of a particular parameter.
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发布时间：2022-10-20 - 摘要：Under the condition of considering joint clearance and lubrication,the dynamics performance analysis of mechanical system is carried out. For the case of the joints with clearance model as a contact pair with dry contact,based on the Lankarani- Nikravesh contact force model,the normal contact force model between the elements of clearance joint is built,the friction forces are calculated by using a modified Coulomb friction model. For the lubricated case,the hydrodynamic theory for dynamics is used to compute the fluid pressure based on Reynolds equation. Subsequently,the dynamics model of mechanical system with joint lubrication is established via the equations of motion for multi- body systems. The slider- crank mechanism is taken as an example to compare the dynamic performance of this mechanism in the case of with lubricated model and without lubricated model. The numerical results point out that the performance of this mechanism with lubricated joint is closer to that of an ideal joint.
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发布时间：2022-10-20 - 摘要：The Synchronizer is an essential part of the manual transmission. The basis for the synchronizer optimization is provided by studying the influence of the synchronizer shift sleeve parameters on shifting performance. The 3D model of synchronizer is established by using UG and simulated in ADAMS. Then the accuracy of the model is verified according to the simulation results and the theoretical results. The optimal range of the shift sleeve Mei angle and the influence law of the change of the positioning ball groove angle of shift sleeve on synchronization time and shifting resistance which caused are got through the analysis of the synchronization theory.
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发布时间：2022-10-20 - 摘要：According to the work situation of coal plough,considering the plough cut resistance,friction resistance,pre tight force of plough chain,sprocket of polygon effect,and the effect of the force produced by speed changes on sprocket and so on in actual work process,the dynamics model with appropriate simplified of the coal plough is established. By using the Matlab,the simulation analysis is carried out,the time course of plough chain tension and speed in different condition plough cut resistance are got. By using the Miner fatigue damage theory,the fatigue life analysis of plough chain of coal plough is carried out. A basis for the reliability analysis of coal plough working condition and coal plough chain is provide by this study.
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发布时间：2022-10-20 - 摘要：Aiming at the friction and meshing composite transmission V belt system,which used in a certain oilfield beam pumping,the simulation model of the V belt drive system is built based on the rigid- flexible coupled dynamics software Recurdyn,and the dynamics simulation analysis is carried out,the transmission performance is obtained. The transverse vibration of the system is analyzed by changing the speed,tension and load,and the rule of the transverse vibration of the system is got,the simulation basis for the research of friction and meshing composite transmission V belt is provided.
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发布时间：2022-10-20 - 摘要：The Solid Works model of high speed inner gear ring in planetary gear speeder is established,by using the ANSYS Workbench software,the modal analysis of the high speed inner gear ring is carried out,the natural frequency and vibration model are obtained. By the calculation results show that the model can produce resonance in the process of transmission. By improving the design and analysis again,the design can avoid resonance and meet the requirement is found out,the experiments to verify the reasonability of calculation results is carried out.
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发布时间：2022-10-20 - 摘要：In order to improve the reliability of light high- speed marine gearbox design,the finite element method is adopted to establish the finite element statics model of the gearbox body. Through the analysis of the simulation software,the displacement and stress distribution of the box body ahead running and reverse condition are computed. According to the analysis results in the weak structure,the box structure is optimized. The strength of the optimized gearbox tends to be uniform and the structure is more reasonable than previous design,a foundation for the manufacture of the gearbox is provided.
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发布时间：2022-10-20 - 摘要：Based on energy release rate criterion,a reliability analysis model is presented for the gear fracture. Firstly,the formula of gear fracture energy release rate is deduced,then the material parameter,crack size,load which affecting on gear fracture are regarded as random variables. The performance function of the crack structure failure is built by taking advantage of the energy release rate criterion. The first- order second-moment method and stochastic finite element method are used to calculate the reliability. The computation results show that this suggested method has advantages of high accuracy and efficiency.
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发布时间：2022-10-20 - 摘要：The basic principle of jaw clutch is introduced. The stage division of engagement process is carried out and the stages of smooth joint of the allowed speed differences is determined through the detailed analysis of engagement and separation process of positive trapezoid jaw clutch. The keeping engagement and separation conditions is studied and the calculation formula is given. The overload protection is analyzed and the maximum manipulating oil pressure of overload protection is given.
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发布时间：2022-10-20 - 摘要：The dynamic characteristic simulation analysis model of a directional drilling machine power head gearbox for different levels of complex is established based on the detailed introduction of the modeling method of main components in gearbox,the influence of the stiffness of bearings and housing on dynamic characteristic of gear drive system is discussed. The results show that the bearings stiffness and housing flexibility has a significant influence on the dynamic characteristic and cannot be ignored in the analytical model; Increase the bearing stiffness and housing stiffness can effectively improve the system natural frequency,reduce the modal displacement and the gear dynamic transmission error; The gear tooth surface contact stress is relatively sensitive to the gearbox housing,but is not to bearing stiffness. The modeling presented method and the results of simulation on dynamic performance of the gearbox has an important guiding significance to the design and analysis.
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发布时间：2022-10-20 - 摘要：The causes of crawl phenomenon of chain propulsion equipment are analyzed. According to the structure characteristics of the equipment,the chain is regarded as an elastic element,also considering the polygon effect when the sprocket wheel rotates,the motion differential equations are set up. Based on the solving result,the impacts of chain stiffness,sprocket parameter on the velocity of the load is analyzed. Then,the stiffness weak of the chain is the main reason which leads to the load crawl,especially when the equipment starts or the resistance changes. The elastic characteristics of the chain will cause the load speed change regularly,and produce resonance with the sprockets easily. At last,several measures for solving crawling problems is proposed directing to a particular equipment.
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发布时间：2022-10-20 - 摘要：Focusing on the existing problems in the domestic NC gear shaping machine,such as the manufacturing cost of helical guideway are expensive and replacement requires a fair of time and a lot of skills. The mechanical structure for realizing the synchronization between the additional rotation and generating motion is proposed based on the principle of helical gear shaping,an adjustable device is added in the existing NC shaping machine,which did not require the replacement of the helical guideway responds to the production of workpiece with different helical angles,the specific methods to achieve the additional rotation is discussed. The results show that the mechanism can meet the production of workpiece with different helical angles,the auxiliary time of shaping process is shortened,all of these can improve the efficiency and flexibility greatly.
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发布时间：2022-10-20 - 摘要：A topology optimization method based on Nastran card quickly modifying parameters is proposed to solve the problem of modifying parameters of the complex components in the process of topology optimization.In the process of the model modification,the load calculation results can be directly imported to the Nastran topology optimization file to replace parameters of the original one. In consequence,the parameters are quickly modified,the accuracy of parameter modification is increased and the process of the model modification is simplified. In order to further verify the adaptability of Nastran cards quickly modifying parameters topological optimization method to the complex components model,one transmission housing is taken as a research object and its gearbox topological optimization model is modified separately by the Nastran cards quickly modifying parameters method and the Optistruct software. The result shows that the results of the two methods are the same in the same initial condition. The application practice indicates that the Nastran cards quickly modifying parameters method is an effective way to solve the problem of modifying parameters of the complex components.
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发布时间：2022-10-20 - 摘要：An experimental prototype of in- line,low pulse pulsing continuously variable transmission（ CVT） is designed and manufactured,its basic structure and working principle are introduced in detail. The transmission efficiency of CVT is investigated by experimental method,a transmission efficiency test bench of the CVT is established,and the transmission efficiency experiment of the CVT is carried out. The experiment results show that the power losses of the CVT almost linearly increases with the increasing of the output torque,then increases gradually after a peak and tends to be stable,and decreases later. The transmission efficiency of the CVT and output torque is linear relationship within the allowable range.
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发布时间：2022-10-20 - 摘要：Through picking up the signal on the blast furnace top gearbox transmission model,using wavelet technology and the envelope demodulation method,the signal analysis is carried out,the gearbox online vibration monitoring system is established. At the same time,the important function of 133 Hz characteristic frequency to the precontrol of equipment working state is put forward.
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发布时间：2022-10-20 - 摘要：The special transmission accuracy of detection test bed of gearbox is developed for the requirements of high- precision batch produced- gearbox,its mechanical structure has a modular design,which makes the test bed has the characteristics of high precision,easy to install,simple operation. By using the computer control,servo motor and precise angle measurement sensors,the test bed can control the circuits,the parameter detection of gearbox backlash,driving accuracy and efficiency can also be realized. By using the wavelet analysis in the single frequency filtering technology of its analysis software,the errors caused by all levels of the gearbox transmission chain can also be extracted by the test- bed.
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发布时间：2022-10-20 - 摘要：The F2 gearbox of Angang Steel Company Limited is introduced. Through the improvement design of the gearbox speed ratio,center distance and bearing of this gearbox and the structure strengthen,the performance of the all aspects of gearbox are improved.
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发布时间：2022-10-20
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