最新刊期
期 9 ， 2015
- 摘要：In order to analyze the additional moment and the characteristic of the meshing tooth when the inter- axial tilt angle exist in the crown gear coupling,the geometric analysis method is taken to calculate the minimum circumferential clearance between the teeth,which can be recognized as the requirement of teeth meshing. The position of the contact point and the clearance between the teeth surface on the different inter- axial tilt angle are analyzed. According to the Hertz contact theory,the osmolality and contact force of the tooth surface contact point can be calculated,so that the additional moment of the coupling can be calculated. The result shows that the inter- axial tilt angle of gear coupling shafts due to inhomogeneous distribution of the mashing point in the circumferential direction,and the variation range turns larger when the inter- axial tilt angle and the tooth surface crowning radius get larger. The relative contact force coefficient is defined to reflect the asymmetry level. When the turning moment is 4000 N·m and the inter- axial tilt angle is 1. 1°,the relative contact force coefficient is about 3. 3 and the contact teeth pairs is about 2 /3 of all. The movement of the meshing point can due to the additional moment,so that the coupling will roll about the direction which vertical to the axle,the additional moment takes about 6% 15% of the turning moment,and it will increase with the inter- axial tilt angle.
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发布时间：2022-10-20 - 摘要：The surface roughness data of a disc with longitudinal roughness texture is measured by a roughness profile measuring analyzer firstly. With the help of the nonlinear Fourier transform,the measured data is used to form a roughness function which is then added to the oil film thickness equation and a model of mixed Elastohydrodynamic lubrication for a pair of mechanical parts in higher pair contact is established. Based on this model,45 groups numerical calculations are carried through changing lubricant viscosities. The computing results show that the average oil film thickness for rough surfaces is smaller than the corresponding value for smooth surface. But the two tend to consistent when the film ratio exceeds a specific value. As the viscosity increases,the maximum value of contact stress on rough surface decreases gradually,but it is always greater than the corresponding value for smooth surface contact. However,the both are less than the corresponding Hertz stress regardless of rough or smooth surface contact,which indicates once again that a scientific lubrication is very helpful for increasing the contact fatigue life of mechanical parts.
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发布时间：2022-10-20 - 摘要：The non- circular gears which have the characteristics of the ellipse is induced to elliptical family gear,the curve characteristics are discussed and the general mathematical model is summarized. On the basis of in- depth analysis of cylindrical gear,bevel gear and small module gear accuracy standard,combining with the characteristics of elliptical family gear,its accuracy standard,single deviation items and comprehensive deviation item are formulated,the 5 grades accuracy calculation formula is deduced,the accuracy grade is divided,the grade proportion is initially determined. On the basis of the summarizing of gear meshing measurement methods,the comprehensive meshing measurement model of elliptical family gear is researched,a train of thought for the accuracy evaluation system establishment and the deviation item effective measurement of elliptical family gear and the diversified development of gear industry is provided.
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发布时间：2022-10-20 - 摘要：Aiming at the problem of the installation space of double cross universal joint steering transmission shaft is limited,it is difficult to meet the condition of constant speed drive,and need to adjust the phase angle to reduce the rotating speed fluctuation,the rotating speed ratio and rotating angle equations of steering transmission shaft are established by means of spatial geometric projection method,and the equation is verified by using the constant velocity condition. The influence of phase angle on rotating speed ratio are quantitatively analyzed,the results show that the input shaft and output shaft can realize constant speed drive while two transmission angle are equal and the phase angle is equal to the transmission plane angle,and the double cross universal joint transmission shaft can’t realize the constant speed drive while two transmission angle are not equal.However,the speed difference of input shaft and output shaft is the smallest while the phase angle is equal to the transmission plane angle. Therefore,this is the best phase angle when phase angle is equal to transmission plane angle and their phases are reversal. Then,the optimal solution formula of phase angle is deduced based on hard point of steering system and the computer program is compiled. The calculation result of the program is accurate by example verification. The conclusion and the program has theoretical and practical significance on system design of automobile steering and research on the transmission of other types universal joint.
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发布时间：2022-10-20 - 摘要：As one of the major vibration and noise sources of electric vehicle,the powertrain is the key to NVH studies. The accurate calculation of the powertrain vibration modes and natural frequency are the foundation of lowering electric vehicle vibration and noise. The finite element model（ FEM） of motor and reducer are established and using four different ways of connection,the finite element modeling method of the centralized drive pure electric vehicle powertrain is discussed,meanwhile the effect of spot welding unit parameter on nature frequency is analyzed. Finally,through the comparing and analyzing the calculation result of the modal hammer test and finite element method,the feasibility of modeling method is testified. Combined with the vibration test,it is proposed that the transmission system should be considered in NVH studies since its effect on the inherent characteristic of powertrain shell. The results provided a foundation for the subsequent dynamic response analysis.
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发布时间：2022-10-20 - 摘要：In view of the problem of the braking effectiveness obvious fluctuation,poor system stability of traditional underground transport vehicle,the wet brake is introduced to the traditional underground unmanned vehicle braking system,the calculation and simulation study of the drag torque which is the main evaluation index of wet brake system is carried out,and the change rule of the braking system drag torque under the condition of different oil supply quantity,oil viscosity and groove type is got. The results show that,with the increase of the oil supply quantity of braking system,the drag torque of all kinds of wet brake friction disk model show an increase trend; the influence of the oil supply quantity change on the drag torque generated by radial oil grooves is more obvious than the spiral oil groove and waffle oil groove; under the condition of high speed,the same external condition,the drag torque generated by radial oil groove is obviously higher than that of the spiral oil groove and the waffle oil groove.
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发布时间：2022-10-20 - 摘要：By using the method of closed vector,the position positive solution model of the symmetrical planar 3- RRR parallel mechanism is built. Aiming at the typical example（ for the frame is the longest and all the rods connecting frame are cranks）,with the help of the numerical method to solve and the reachable workspace of 3- RRR parallel mechanism is mapped by using the Matlab,and compared with the result gained by motion simulation of virtual prototype software Solidworks.
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发布时间：2022-10-20 - 摘要：Aiming at the lower absolute positioning accuracy of robot,the compensation method of establishing the robot kinematics error model through D- H method is put forward. However,the robot structure needs to meet the Pieper law,so only the influence of the joint rotation angle of the robot error model on the robot end error is taken in consideration. The real joint rotation angle of error model can be identified by using the least square method to compensate the error,Meanwhile,and the second time compensation is carried out by using the circle method. At last,the corrected parameters is compensated to the controller so as to improve the absolute positioning accuracy. The method is verified on the developed industrial robot with 6- DOF. The positioning accuracy is improved from 3. 55 4. 45 mm to 0. 924 1. 242 mm after compensation,the effect is obvious and a reliable basis for the research of robot accuracy is also provided.
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发布时间：2022-10-20 - 摘要：The velocity curve not smooth and the sudden change of acceleration will appear when the robot start or stop,resulting in body shock,vibration etc. In the process of robot movement,that no sudden change of acceleration,small changes in velocity and smooth transition in every stages of the movement should be ensured so as to reduce the impact and many other problems due to the change of the speed and the acceleration.Focusing on the above cases,the velocity control of the palletizing robot is studied. Now common acceleration and deceleration method include linear acceleration and deceleration method,exponential acceleration and deceleration method,polynomial acceleration and deceleration method,parabola acceleration and deceleration method and S curve acceleration and deceleration method etc. The linear acceleration and deceleration method,exponential acceleration and deceleration method and polynomial acceleration and deceleration method are analyzed emphatically.
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发布时间：2022-10-20 - 摘要：For the problem of the low efficiency of robot under a certain working environment,a trajectory planning method based on optimal time is put forward. Firstly,by using the seven times B spline curve,the interpolation of the robot position time series is completed. Then the kinematic constraints are transformed into the constraints of B spline control vertex. Finally,the time optimal trajectory meeting the kinematics constraints and torque smoothing is obtained by using genetic algorithm,based on the optimization target of robot joint trajectory optimal running time. The experimental results show that the cumulative effect of the planning algorithm could obviously be reduce the jerk and the optimal time of the robot performing trajectory is improved.
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发布时间：2022-10-20 - 摘要：Aiming at the problems of long distance drilling tool transport system has high manufacturing cost,maintenance difficulty,the V- ribbed belt drive is introduced into the long distance drilling tool transport system,and the system mathematical model is established. The key components of the tensioning device are optimized through optimization design,and the optimization results are verified by the experiment method. The results show that through the research on optimizing the key parameters of drilling tool transport system of the tensioning device,the influences of the key parameters on vibration of long distance V- ribbed belt drive of drilling tool transport system in operation process. Finally,the optimized results are verified by the theoretical calculation and experimental,the optimized system operation process of vibration is obviously reduced,there is providing a certain basis for the follow- up product variant.
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发布时间：2022-10-20 - 摘要：A new gear pair of cycloidal planetary transmission with point contact is proposed. The equations of tubular meshing tooth surfaces and contact locus of internal cycloidal planetary transmission are derived respectively. The design example is given and the 3D solid models are established. A new approach for calculating the sliding ratio of tooth surface is put forward based on the contact locus. According to this method,the sliding ratios of internal cycloidal planetary transmission with point contact are solved and the main influence factors are also analyzed. The results show that this new type of gear pair has the characteristic of point contact and the pure rolling between mated tooth surfaces can be obtained. Meanwhile,it has the higher transmission efficiency.
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发布时间：2022-10-20 - 摘要：On the basis of theoretical analysis of the working mechanism of traditional magnetic field modulation gear,a cylinder type linear magnetic gear is designed,whose transmission ratio is 2. 67. Its air- gap flux density and static thrust characteristics and dynamic thrust characteristics are calculated by using the finite element analysis method. The correctness of the design is validated through the calculate results. Based on the above,the influence of magnetic field modulate ring size on the gear static thrust and the change rule of the influence are analyzed,and a basis for parameter optimization of a linear magnetic gear is provided. At the last,the optimization of relative width of magnetic field modulate ring is to 0. 6 and the thickness to 3 mm,the air gap width of high- speed side to 1. 2 mm.
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发布时间：2022-10-20 - 摘要：The basic structure based on metal belt CVT（ Metal Belt Continuously Variable Transmission,referred to as MB- CVT）,through the introducing the jointless wire rope and changing the metal block shape,a new type of metal belt CVT is designed,namely the Wire Rope- CVT（ WR- CVT）. Through the comparative analysis the constraint condition of two kinds of CVT metal belt ring and wire rope in six degrees freedom,the result shows that the WR- CVT has a stable working state of MB- CVT. The formula of calculating lateral pressure of WR- CVT wire rope and metal block arc groove contact is obtained,the analysis of WR- CVT wire rope and metal block arc groove longitudinal contact and non- contact the relationship of force are carried out,the foundation for the further study of WR- CVT is provided.
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发布时间：2022-10-20 - 摘要：A new design approach of non- circular gear is proposed in order to solve the design problems of non- circular gear on continuously variable transmission. Using this approach,the transmission ratio function of non- circular gears composed by two functions in the entire cycle is smooth and continuous at the connection points,and then the cusps of the non- circular gear pitch curve are eliminated in order to ensure the smooth transmission. Finally,the example is given,the transmission ratio function of non- circular gears on continuously variable transmission is redefined and the non- circular gears of the smooth and continuous pitch curve is redesigned by using the approach. This approach can also be applied to the general design of non- circular gear.
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发布时间：2022-10-20 - 摘要：In order to build a basic high power density friction plate（ vice） procedural design model,forming a fairly complete friction plate（ vice） design system,a comprehensive friction and wear performance design and friction plate mechanical strength design engineering system design method is presented based on actual experience considered a critical dimension tolerance design,the design suitable for high power density of the engine compartment with a friction plate design is summed up as friction and wear property of design and friction plate mechanical strength design two aspects,through linking with friction plate test design parameter library of the corresponding parameter,a technology platform of bearing friction plate design,research is established,it is improved the design precision and efficiency greatly.
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发布时间：2022-10-20 - 摘要：The structure and transmission principle of the two tooth difference cycloid movable tooth transmission are introduced,and the tooth profile is designed. The tooth outline of center gear is analyzed with simulation software,and the radius of curvature of the center gear is calculated. The position of the minimum radius of curvature of the center gear is ascertained,and the conditions to avoid the tooth profile interference are given. The influences of the structural parameters on minimum radius of curvature of center gear theoretical tooth profile are analyzed. Combined with a single degree of freedom vibration model,the dynamic response of movable tooth transmission is analyzed.
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发布时间：2022-10-20 - 摘要：A practical type of underactuated three- fingered end- effector for an apple picking robot is proposed,the end- effector structure is designed and the 3D modeling is completed by using the Unigraphics NX. Through designing the structure of multi- phalanges finger and tendon rope,the purpose of improving the flexibility of mechanism grasping is achieved. Based on the movement principle of finger grasping motion,the relationship between the tendon rope force and the joint torque is analyzed. Under the constraint condition of ultimate load that cannot damage the surface of apples,the key component torsional spring is designed and the structural parameters of the torsional spring are determined with the goal of achieving reliability and flexibility of the mechanism motion. The flexibility and applicability of the mechanism are effectively improved. The end-effector is also suitable for other globular or different sizes of fruit and it has certain applicability to grab.
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发布时间：2022-10-20 - 摘要：As a common quick return mechanism,the plane- four- bar mechanism is widely used in engineering. In order to improve the design accuracy and efficiency of the quick return four- bar mechanism,a relatively simple method to establish a analytic equations of the quick- four- bar mechanism is proposed through the analysis of the traditional analytical method and combining the geometric principle. By using the MATLAB software,the equations can be solved quickly. By changing the parameters value of equations,the quick- return four- bar mechanism can be designed quickly and accurately.
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发布时间：2022-10-20 - 摘要：For the issues of design preferences,braking force fluctuation of eddy current retarder of heavy duty construction vehicle during use,the heavy duty construction vehicle eddy current retarder is regarded as research object,the calculation formula of retarder braking torque is deduced,and combine with the actual object of key parameters and the influence of each parameters on braking performance are considered,the optimization design of the eddy current retarder is carried out through optimization design theory. Finally,the optimized model is validated through the experiment. The results show that the eddy current retarder of heavy duty construction vehicle after optimization design can improve the fluctuation of braking torque and braking time.
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发布时间：2022-10-20 - 摘要：For the reason that the position solution of a parallel mechanism is hard to be solved directly,the solution of positive position are parsed by the method of transformation to solve object location based on the solved inverse position solution in the 3- PRS parallel mechanism,and the velocity and acceleration of the passive joints are obtained by the D’Alembert principle,which can avoid the complexity of the direct derivation on the spatial mechanism. Through the analysis of an actual 3- PRS parallel mechanism instance,the results show that the method of objects transformation is simple and effective for solving the position positive solution of the parallel mechanism. At the same time,it is pointed out that the derived movements also exist besides the main three motions of 3- PRS parallel mechanism,this reveals that the derived kinematics must be taken into account in actual usage.
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发布时间：2022-10-20 - 摘要：The two- stage planetary gear transmission system model is established based on LMS Virtual.Lab Motion platform. The dynamics simulation model is established in LMS with the two- stage planetary gear system coupled model and considering the problem of nonlinear vibration of gear system. The frequency domain load map and time domain load map of gear meshing force of the system are obtained by simulation that can be used for the research of vibration and noise later. The feasibility of gear system dynamics analysis with the help of virtual prototype is verified by comparing simulation data with theoretical calculations,and a new path for the research is provided.
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发布时间：2022-10-20 - 摘要：In order to solve the issues of all- terrain vehicle（ ATV） axle housing design process appears poor design efficiency and timeliness security,a reliability calculation method of certain type of all- terrain vehicle integral type axle housing based on the finite element method combined with the blind number theory is presented,the all- terrain vehicle axle housing design methods in full of uneven road is obtained by taking the integral type axle housing under the condition of the loaded with uneven road,wheels withstand the maximum tangential force,wheels withstand the maximum lateral force,and the axle housing conditions of stress and deformation as restriction. The simulation results show that based on the analysis of the results of finite element analysis,the calculation efficiency of the design of the all terrain vehicle axle housing is improved,combined with the load and the strength of the time- varying characteristics,a simple calculation method for the structure reliability of the all terrain vehicle axle housing by using blind number theory is provided.
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发布时间：2022-10-20 - 摘要：On the basis of geometric theory of cylindrical indexing cam,the 3D parametric solid modeling of cylindrical indexing cam is realized based on VB 6. 0 and Pro / E. The friendly interface which can calculate the contour surface data of parametric cylindrical indexing cam is designed through the VB programming language. This interface can be used to calculate the value of the relevant contour surface points through basic parameters input of cam and the choosing of motion law of cam follower,and it will save the file as the format of "ibl". After that,the file is imported into Pro / E 3. 0 to generate curve and then the curves are merged into surface. At last,the normal offset and solid resection operation of theoretical contour surface are carried out,and the cam solid model is obtained after cam blank Boolean subtracting operation.
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发布时间：2022-10-20 - 摘要：Aiming at the practical needs of the cement loading industry,a kind of bagged cement automatic loading machine is developed and designed. Besides a truck loading manipulator with the characteristic simple structure,fewer driving parts,easy to control is presented. Firstly,the overall structure scheme of the automatic loading machine and basic structure of loading manipulator based on parallel mechanism are introduced,the kinematics model of manipulator is established,the kinematics inverse solution of position,velocity and acceleration are obtained. On the basis of the motion trajectory planning of the manipulator end,through importing kinematics solution into the movement simulation software Matlab,the kinematics simulation calculation is carried out,the mechanism change of position,velocity and acceleration curve are drawn out,a reference for the mechanical design and optimization of a manipulator mechanism and the type selection of drive servo motor is provided.
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发布时间：2022-10-20 - 摘要：According to the requirements of overrunning coupler to the floating micro wave power generating device,the friction loss rate of wedge- type overrunning clutch at overrunning states is analyzed and the parameters mathematical models of the wedge- type overrunning clutch are built. Taking the minimize volume and the friction loss rate as design aims,with the strength and the sizes of various parts to be the constraint conditions,the optimization model is established,and the mathematical model is solved by using the MATLAB. Finally,compared with the conventional design parameters,the results show that the volume of the optimization design is only71. 99% of the conventional design,and the friction loss rate of the optimization design decreased 2. 26 percentage,which can makes the floating power generating device more compact,lighter and more efficient.
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发布时间：2022-10-20 - 摘要：In order to solve the traditional heavy vehicle braking system braking performance are not stable,installation space limitations,a brake integrated system scheme through arranging electromagnetic brake on the drive axle dynamic input shaft and layout wet brake Inside the integral drive axle is proposed,the mathematical model of integrated brake system is established through the analysis of the layout scheme of device structure and working principle,and through the experimental methods to verify the feasibility of integrated brake system.The results show that the half shaft wet brake torque presents increased trend,at the end of the braking,the brake torque of the brake integrated system is provided solely by the half shaft wet brake,the electromagnetic brake torque first increased and then decreased,the torque at the end of the braking become to zero; the brake integrated system braking torque decreases with the half shaft speed decreases,a certain fluctuation exists during the period; in the braking process of brake integrated system,the wet brake load can be significantly reduced and the oil temperature can be controlled in a suitable range.
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发布时间：2022-10-20 - 摘要：The mathematical model of the planar eight- bar mechanism is established by applying the theory of optimization design,on the basis of this,the ADAMS / View is used to establish the parametric model for the eight- bar mechanism as well as to conduct the optimization and movement simulation. The result of the optimization design and the simulation curves show that the method of optimization is feasible and fits exactly,so it can be provided for reference for the optimization design of the similar mechanism.
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发布时间：2022-10-20 - 摘要：There are more stringent requirements of return difference and rigidity for precision reducer used in heavy industrial robot,the return difference and rigidity of heavy type 2K- V reducer can be tested by the self- developed experiment device,the comparative test research of similar products in abroad is also carried out,and the test torsion stiffness curves are drawn. By contrast experiment test results analysis,the return difference and rigidity of domestic heavy type 2K- V reducer comes up to the requirements of international standards,and a kind of effective means for evaluating the characteristic of heavy precision reducer is provided by the establishment test platform.
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发布时间：2022-10-20 - 摘要：The non- linear bearing force in the working state of the rolling bearing is deduced and non-linear dynamics equations of a system are established. The system axis path chart,the bifurcation diagram and the Poincare figure are drawn in Matlab and used to analyze the characteristics of the system vibration with the different parameters. The numerical method is used to solve the equations and the displacement values of system vibration are obtained. The results show that the change of the non- linear bearing force will cause the vibration of the system and bifurcation phenomena will appear in the system. The speed,damping and radial force are important parameters that influence the vibration. By choosing reasonable working parameters,the vibration of system can be reduced and the stability of the system can be improved.
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发布时间：2022-10-20 - 摘要：For the study of the dynamic characteristics of non- circular gear,a transmission box of non-circular gear is designed. According to its dynamic characteristics,a measurement scheme is put forward and the electric parts of its relevant power system,breaking system and detection system are selected,which are used for the putting up of the dynamic testing experimental platform of non- circular gear. The parameter control and data acquisition systems are designed,which could realize the control of testing device and the processing of data acquisition through the computer. The dynamic characteristics of a pair of non- circular gear transmission are tested and analyzed by using this system.
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发布时间：2022-10-20 - 摘要：The mesh matching method is proposed for clearance error and non point contact problem caused by mesh discretization in the finite element analysis rolling bearing. Firstly,the mesh matching and the importance of the matching to contact calculation in finite element analysis is expounded. Secondly,the mesh matched 3- D model of ball bearing is analyzed. Finally,the mesh matching and compacting is analyzed quantificationally based on a simplified model of bearing contact problems. The results show that,the mesh non-matching causes larger error for arcs and cambered surfaces contact problem,the effect of mesh matching is obvious; the mesh matching and compacting can significantly improve the accuracy of analysis for Hertz contact problem; a better analysis precision can be achieved when the mesh matched and non- compacted rolling bearing model is used. The study has a certain guiding significance for accurate finite element modeling and analysis of rolling bearing.
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发布时间：2022-10-20 - 摘要：A kind of rectangular straight rack connecting structure is proposed for tight junction between movable beam and stand column,so as to ensure the load bearing entirety of movable beam and stand column in each stroke position. The contact stress contour under different loading and in different contact state is obtained by using finite element software MSC. Marc. The results show that the max contact stress is increased with the increasing of load,and when the load exceeds certain value,the max contact stress has a linear relation with load,and also the value and increase amplitude of max contact stress of fixed rack is much higher than that of movable rack; when the movable beam is in different stroke position,namely the structure has different contact state,the value of max contact stress didn’t change obviously,therefore,the structural strength can be checked on the basis of stress level of fixed rack.
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发布时间：2022-10-20 - 摘要：A torsional vibration model of the K- H- V cycloid steel ball transmission system is established with considering the direction changing of engagement force and the multi- balls engagement in transmission process. By analyzing the position relationships of each engagement force and the displacement relationships of each component,the governing differential equations of the system and the dimensionless equivalent engagement rigidities of each transmission disc are derived. And then,the frequency spectrum of the engagement rigidity excitation is analyzed,and the influences of the system transmission ratio and the cycloid curtate coefficient to the engagement rigidity excitation are discussed. At last,the natural frequency,the principal mode and the steady- state response of system are calculated. The results show that the cycloid steel ball transmission system is a parametric vibration system. The engagement rigidity excitation between the center disc and the planetary disc is a periodic and time- variant function,and the high- order harmonic components are included in the frequency spectrum.
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发布时间：2022-10-20 - 摘要：The transmission efficiency of driving axle directly affects the vehicle fuel consumption,and the difference of driving axle bearing clearance affects transmission efficiency. On the basis of the theory research,it is found that,by benchmarking analysis and further experimental research,through increasing the bearing clearance,the transmission efficiency of driving axle can be improved,and the vehicle fuel consumption is decreased. Meanwhile,through increasing the bearing clearance,the life mileage of the bearing is reduced and the noise of driving axle is increased. Considering minimizing the user cost,the proper increasing of bearing clearance has great important significance on improving the transmission performance of driving axle.
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发布时间：2022-10-20 - 摘要：Box housing plays an important role in the course of the entire operation of the gearbox in the subway,not only withstanding the bearing’s load,also the extemal excitation and noise has an important influence. Modeled the box housing by the Pro / E,The three- dimensional solid modeling of the subway gearbox housing is carried out through the Pro / E,then imported into the Workbench for finite element modal analysis,the natural frequency and vibration mode are got,and the results of experimental mode analysis are compared with the finite element modal analysis,the feasibility of the modal analysis is test. The harmonic analysis is carried out based on the finite element modal analysis,the anti- vibration performance under the effect of different frequency are obtained. Which can arrange the reasonable housing structure,and a reliable basis for the further analysis of the dynamic response of the gearbox is provided.
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发布时间：2022-10-20 - 摘要：Aiming at a designed W- 5D type underwater sampling manipulator,the parameters and forward kinematics model is established by using the D- H method. According to the structural characteristics of the adjacent 3 joints with parallel axes of the manipulator,by a geometrical method is introduced based on the method of separation of variables,the inverse kinematics closed solution is obtained,whose structure is concise and easy to operate,the requirement of manipulator in the operating environment of underwater is meet,and the basis for the manipulator motion planning and trajectory control is provided. The simulation model of the manipulator is established by MATLAB Robotics Toolbox. The toolbox ikine function is an important method to get the inverse solution of industrial robot,by comparing with the results from the ikine function the superiority and feasibility of the closed solution is verified.
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发布时间：2022-10-20 - 摘要：A rolling surface crack of the cylindrical roller bearings used in an aeroengine fulcrum is found after work,the material for rolling elements is W9Cr4V2 Mo. Through the morphology observation,energy spectrum analysis and metallographic analysis of the rolling surface morphology crack,and the test results are compared with the material for M50 and GCr15 of cylindrical roller bearing surface crack,it is obtained that the material surface cracks of W9Cr4V2 Mo rolling body is produced in the process of rolling the rod used in the cold-drawn molding process,the crack nature is forging folding defects.
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发布时间：2022-10-20 - 摘要：The gear- parallelogram mechanism（ GPM） is a kind of geared linkage combinative mechanism with special motion performance. The composition rules of GPM are introduced,and the transmission property of outer teething type and idle gear type of GPM are analyzed. Meanwhile,according to the principle of the variation of the isomorphism,the evolution and mutation of internal teething type is studied. By the comparison of internal and external meshing combined mechanism,the method of changing different mechanism transmission ratio is summarized and the type of internal teething and internal parallel motion of GPM is chosen,which has large transmission ratio,high mechanical efficiency,small size,light weight,compact structure and better smoothness of moving. Some theoretical basis for design new combined mechanism about reducer and speed increaser is provided.
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发布时间：2022-10-20 - 摘要：Taking the automobile headlamp leveler transmission system as study object,based on the mechanical dynamic simulation technology,the dynamic characteristic of leveler transmission systems is studied.The dynamics simulation model of multistage transmission system of leveler is established in ADAMS. The influence of each transmission friction on shaft thrust force is obtained. The test result shows that simulation model can forecast the influence of each transmission friction on shaft output force,the reliability of the model is verified. It can provide as reference for the leveler design and process optimization.
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发布时间：2022-10-20 - 摘要：The toroidal planetary- worm drive mechanism has the characteristics of structural compactness,high transmission efficiency and wide range of transmission ratio. But the popularity degree is not high,because of the processing and manufacturing of the internal toroidal gear is difficulty and the assembly difficulty of toroidal planetary- worm drive mechanism,the vibration and noise may be caused by a slight deviation which is hard to avoid during production,and this will affect the transmission accuracy and efficiency. A new type of the toroidal planetary- worm drive mechanism which is good for reducing the difficulty of the toroidal planetary- worm drive mechanism processing and assembling is proposed. The analysis of the meshing theory and kinematical simulations for the novel planetary- worm drive also is implemented.
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发布时间：2022-10-20 - 摘要：During the design process of the overrunning clutch,on the basis of flexible ring- type overrunning clutch which is based on the traditional flexible body- friction typed Euler formula,the physical model of Euler formula is innovatively extended and a new overrunning clutch- expanding flexible ring- type overrunning clutch is developed. The analysis shows that this overrunning clutch is more suitable for the conditions of high speed and high load,and more easily to design.
- 4
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- 125
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- 1
发布时间：2022-10-20 - 摘要：For solving the frequent failure problem of the cylindrical gear reducer which used in axial flow fan in direct air cooled system. By using the KISSsoft software,the gear reducer is analyzed,and the dangerous points of this reducer is found. According to the analysis result,the structure improvement and checkout are conducted. The result shows that the structures after improvement satisfied the requirements of strength and rigidity. The reference for series of products design and further improvement of gear reducer is provided by the obtained analysis data.
- 3
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- 59
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- 0
发布时间：2022-10-20 - 摘要：In order to solve the problem that reducer is overheating and the spin current is too large when the reducer of copper melting furnace operating,through the analysis of carrying capacity of imported reducer worm gear and worm drive,the measure to improve the transmission capacity is proposed,and the appropriate readjustment of the worm gear pair center distance is carried out. In addition,for maintaining the connection dimensions of homebred reducer consistent with imported reducer,the sizes of the reducer box are adjusted and optimized. In order to improve the contact area of worm gear pair,the scraping- grinding and running- in with heavy load are combined,and as a result,the quality of contact pattern is improved plentifully and the homebred reducer runs smoothly with a low current.
- 3
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- 29
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- 0
发布时间：2022-10-20 - 摘要：The life of transmission element is not equal often occurs in the standard design of the transmission pair,this problem can be effectively solved through the strength matching of transmission element. Starting from the meshing principle,by changing the standard of usual parameters,which makes the design of worm pair can meet the requirements of transmission ratio and strength,but also reflects the structure compact,while the meshing strength matching of transmission parts is realized. The two parameter correction schemes: the method of variable modulus and pressure angle and variable,and the method of single variable tooth thickness are mainly studied. The feasibility and effectiveness of the two methods are proved by the practice.
- 3
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- 88
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- 0
发布时间：2022-10-20 - 摘要：A new kind of eight- legged walking bionic robot mechanical structure is designed. The kinematics equation of the leg is set up. Based on virtual prototyping technology,the mechanism of the bionic robot leg is optimized,and the ability of gradeability,crossing uneven road and the gait planning of the turning are simulated and analyzed. The results show that the eight- legged walking bionic robot has many excellent performances,including controlled easy,flexible movement,good climbing ability and small turning radius. Finally,a small physical prototype of the robot is developed,through which many excellent performances is tested.
- 5
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- 267
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- 0
发布时间：2022-10-20 - 摘要：The dual lead cylindrical worm drive is suitable for high precision indexing and rotary servo axis etc engineering applications。In the light of renovation requirements of a wind tunnel mechanism,based on the analysis of the equipment characteristics and the characteristic of existing drive mechanism,the existing mechanism is replaced by using the dual lead cylindrical worm. The related key point design is analyzed,the new mechanism obtains good use effect.
- 4
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- 50
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- 2
发布时间：2022-10-20 - 摘要：The research status of gearbox test rig system is reviewed at home and abroad. The problem of energy feedback for the gearbox fatigue test rig system is introduced and classified by the energy power flow.The state of the art of research achievements of gearbox test rig system are given as well as the basic working principles and working performances of various dynamometer test bed system are illustrated in detail. The advantages and disadvantages of various structures are compared,and the application scope of various dynamometer test rig system are summarized. The development trends of dynamometer test bed system are reviewed from the energy feedback load and intelligent control.
- 5
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- 411
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- 1
发布时间：2022-10-20
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