122 results about "Meshing stiffness" patented technology

The invention relates to a method for the simulation analysis on the meshing stiffness of a cylindrical spur gear undergoing damaged single-tooth failure. The method comprises the following steps: firstly, setting the correction coefficient of the meshing stiffness of single-tooth and double-tooth meshing section on the basis of the calculation results of the average stiffness according to the finite element method and the national standard method, so as to improve the calculation accuracy of the meshing stiffness of a normal gear according to the energy method; secondly, establishing a finite element model of the spur gear undergoing damaged failure targeting on the failure location of the spur gear by combining the three-dimensional modeling software and the finite-element analysis software, and compiling a simulation calculation program by using the computer language, so as to calculate the time-varying meshing stiffness; and finally, integrating the calculation results of the two steps to obtain the integrated meshing stiffness of the spur gear. By fully integrating the advantages of the corrected energy method and the finite element method, the invention can not only guarantee the calculation accuracy, but also improve the calculation efficiency. The method of the invention for the simulation calculation of the meshing stiffness of the gear undergoing damaged single-tooth failure is effectively applicable in the research on the vibration response mechanism of a gear system.

The invention discloses a nonlinear dynamics calculation method for a gear pair. The method comprises the steps that the feedback effect of vibration displacement to the dynamic contact condition of agear surface of the gear pair in the actual running process is considered, and the nonlinear excitation of the dynamic meshing rigidity and dynamic comprehensive meshing errors is calculated. Dynamiccontact analysis of the gear pair and a system dynamics solution process are combined, and an excitation-response-feedback loop-locked calculation process of the system is achieved. According to themethod, the nonlinear dynamics phenomenon of the gear pair due to parameters such as gear surface errors and shape correction can be acquired, the dynamics behavior of the system in the dynamic contract process can be more truly simulated, and the calculation accuracy of dynamics is improved.

A form of gearing having teeth with different face widths along the tooth height and a method thereof of designing and manufacturing. Different gear tooth face widths are introduced along the tooth height to alter the tooth stiffness characteristic to provide a pair of gears with reduced mesh stiffness variation. The use of variable face widths along the tooth height changes both the geometric properties of the tooth and the load distribution / concentration to reduce the self-excited component of dynamic load, in effect reducing gear noise and increasing power density.

The invention discloses a modeling method for transmitting mechanism torsional vibration analysis of a passenger car under different operating conditions. The modeling method is used in accurate prediction and analysis of transmitting mechanism torsional vibration characteristics of a passenger car under different operating conditions; according to the method, on the basis of a traditional concentrated parameter model, engine excitation, crank link mechanism moment of inertia, time-varying characteristics of gear meshing stiffness, clutch torsional shock absorber and the non-linear stiffness of the gear backlash are added to consideration; a simulation model suitable for analysis of transmitting mechanism dynamics characteristics of passenger car under different operating conditions is established; the engine cylinder pressure data under specific operating conditions is obtained through actual measurement or simulation as excitation; equivalent resistance moments of the rolling resistance and the air resistance are used as load to realize simulation of a passenger car under specific driving conditions. The method of the invention has strong practicality and has simple calculation; the method is suitable for the accurate prediction and analysis of transmitting mechanism torsional vibration characteristics of a passenger car.

The invention proposes a method considering axial deformation for calculating time-varying meshing stiffness of a helical gear. The method aims at improving the accuracy of calculating the meshing stiffness of the helical gear. The method comprises the implementation steps of calculating the end surface bending stiffness, end surface shearing stiffness, radial compression stiffness and end surfacetooth base stiffness of the helical gear; calculating contact stiffness; calculating the end surface meshing stiffness of a single tooth pair; deducing and calculating axial bending stiffness, axialshearing stiffness and axial tooth base stiffness; calculating the meshing stiffness of the single tooth pair; calculating the time-varying meshing stiffness. According to the method, the influence ofaxial meshing force on the time-varying meshing stiffness of the helical gear is considered, a calculation expression for the quantitative calculation of the axial bending stiffness, axial shearing stiffness and axial tooth base stiffness of the helical gear is deduced, the time-varying meshing stiffness of the helical gear is calculated by combining all the stiffness in the end surface direction, the calculation accuracy is improved, and the method can be used for the dynamic performance analysis and optimization design of the helical gear.

Disclosed herein is a multi-mesh gear system, such as an epicyclic gear system, in which (a) optimal performance is not load-specific and (b) the same profile modifications can be applied on both flanks of the common gear. This is accomplished through a novel combination of a constant system contact ratio and gearing having mesh stiffness variation reducing, or MSVR, modifications. An MSVR modification, such as Differential Crowning, will minimize the self-excited component of dynamic load for gear meshes across different operating loads, resulting in an optimized gearset. The specification of a substantially constant contact ratio for the multi-mesh gear system allows the same MSVR modification to be used on both tooth flanks of the common gear, reducing the cost and complexity of manufacture.

The invention relates to a quantitative calculation method for the meshing stiffness of a gear with a minor defect. In order to describe the influence of a typical gear fault on the time-varying stiffness characteristic, a meshing stiffness energy method calculation model is firstly introduced, wherein five kinds of elastic strain energy, which refers to bending, shearing, radial compression, contact and base deformation, are respectively considered, and five corresponding stiffnesses are further formed. The quantitative calculation method is based on the energy method, the influences of case crush, tooth root crack and tooth breakage on the stiffness distribution are discussed one after another. Aiming at spalling defects, the influences of spalling length (in the meshing direction) and spalling width (in the tooth width direction) on a stiffness distribution curve is researched, and the quantitative relationship between the spalling size and the stiffnesses degradation is obtained. In the aspect of flexural fatigue crack, the change rule of the stiffness curve along with the crack depth, and the quantitative relationship between the stiffness curve and the crack depth are discussed. In the aspect of broken gear tooth, the influence of missing of a single tooth on the stiffness distribution is discussed. By adopting the quantitative calculation method, the actual meshing situation can be really reflected, the complexity and computation in the process of solving can be lowered.

The invention relates to an amended gear pair meshing characteristic analysis method taking drum modification into consideration. In order to acquire basic parameters of a gear pair and drum modification parameters, gear teeth of the gear pair are divided into N independent even web gears in the direction of tooth width; the time-variant meshing stiffness of each web gear pair is calculated by adopting the gear pair meshing characteristic analysis method taking prolonging the meshing influence into consideration on the basis of the error of a gear profile of a drum modification gear pair; a meshing gear pair three-dimensional model comprising drum modification is established through three-dimensional drawing simulation software, the three-dimensional model is guided into an ANSYS software to create a three-dimensional finite element contact model, and time-variant meshing stiffness data in the whole meshing process of the gear are solved. The analysis method is simple in modelling process and low in calculated quantity, the requirement on a computer is low, and the calculation result is accurate and true.

The invention relates to a method for measuring variable stiffness in the process of gear mesh. A state, between single-tooth and double-tooth alternative mesh critical states, of two gears serves as a mesh measurement period, and a formula (see the instructions) in one mesh measurement period is marked as a rotation angle of a pinion, wherein the epsilon is a gear contact ratio, Zp is the number of teeth of the pinion, i can be anyone in 1, 2, 3..., 10, the marked rotation angle thetai of the pinion serves as a measuring position, and stiffness values Ki at all measuring positions of the pinion are connected to obtain a meshing stiffness in one mesh measurement period of the gears. By means of the method for measuring the variable stiffness in the process of gear mesh, the variable stiffness in the process of gear mesh can be rapidly measured, the practical measurement efficiency can be greatly improved, test time is saved by setting the mesh measurement period and determining the measuring points, a rapid and effective verification test is provided for the design of gears, more importantly, the efficient measuring method even proximate to the production rhythm is provided for manufacturing enterprises, and the method is suitable for being applied to mass production.

The invention belongs to the technical field of mechanical dynamics, and particularly relates to a method for calculating time-varying mesh stiffness of a bevel gear pair. The method includes: S1, acquiring basic parameters of the bevel gear pair; S2, separating a bevel gear pair model into N independent and uniform laminar straight gears along a tooth width direction; S3, determining whether the N laminar straight gears participate in meshing or not at the meshing position j; S4, calculating the time-varying mesh stiffness for every laminar straight gear; S5, summing the time-varying mesh stiffness of all the laminar straight gears to obtain the time-varying mesh stiffness of the bevel gear pair. The method for calculating the time-varying mesh stiffness of the bevel gear pair has the advantages that nonlinear contact is taken into consideration, influences of base body stiffness and extended meshing are corrected, an analyzing model is improved, and calculating precision is improved.

The invention relates to a straight-toothed spur gear wearing capacity computing method. The straight-toothed spur gear wearing capacity computing method includes the specific steps of firstly, determining intertooth dynamic load borne by two pairs of gear teeth meshing pairs according to time-varying meshing stiffness and geometric side clearance of a gear and computing surface pressure of meshing points; secondly, computing slip speeds of the meshing points according to a gear meshing theory; thirdly, computing wearing depths according to the surface pressure and the slip speeds of the meshing points, wherein the geometric side clearance of the gear is computed according to wearing depth computation in the step 3. The straight-toothed spur gear wearing capacity computing method takes a dynamic load updating process under a practical geometric side clearance into consideration, determines wearing capacity of every tooth position of the straight-toothed spur gear accurately and reasonably, and provides an effective approach for reducing gear vibration impact and prolonging gear service life.

The invention provides a method for solving dynamic characteristics of an involute straight gear transmission system. The method comprises the steps: S1, establishing an involute straight gear transmission system nonlinear kinetic model based on a concentrated mass method; s2, considering the time-varying meshing stiffness, the dynamic transmission error, the friction, the eccentricity, the shapecorrection, the gap, the gravity and the nonlinear bearing force, and deriving an involute straight gear transmission system nonlinear kinetic equation based on a Lagrangian equation; s3, based on Runger-Kutta method to solve the dynamic characteristics of the involute straight gear transmission system. According to the method, nonlinear influence factors such as time-varying meshing stiffness anddynamic transmission errors are comprehensively considered, and a mass concentration method, a Lagrangian equation and Runger-Kutta method is combined and applied to solving the dynamic characteristics of the involute straight gear transmission system, the solving accuracy and efficiency of the dynamic characteristics of the involute straight gear transmission system are improved, and the methodhas important significance for improving the meshing stability and bearing capacity of the gear transmission system, reducing the friction loss and the like.

The invention relates to a gear transmission system non-linear dynamics modeling method. Based on the problems that time varying meshing stiffness and damping coefficients in a traditional gear transmission system dynamics model cannot be directly showed in general multi-body dynamics software, improvement is carried out on the gear transmission system non-linear dynamics model. The time varying meshing stiffness between gear pairs and the arousal effect on a system by damping are equivalent to the time varying meshing force and the time varying meshing torque at a driving gear barycenter and at a driven gear barycenter, and a function expression of the time varying meshing force with the time varying meshing stiffness and the damping coefficient as independent variables and a function expression of the time varying meshing torque with the time varying meshing stiffness and the damping coefficient as independent variables are given out. A gear transmission system non-linear dynamics model established through the method guarantees calculation precision and efficient calculation speed.

The invention belongs to the technical field of mechanical dynamics, and particularly relates to a gear pair abrasion loss prediction method based on dynamic meshing force, which comprises the following steps: S1, acquiring basic parameters of a gear pair; S2, calculating the time-varying meshing stiffness and static load distribution coefficient of the worn gear pair according to the acquired basic parameters of the gear pair and a gear tooth bearing contact analysis method; S3, introducing the time-varying meshing stiffness obtained through calculation into a gear rotor system dynamic modelto calculate a dynamic meshing force and a dynamic load distribution coefficient of the gear pair; and S4, adopting an Archard wear theory, a wear coefficient empirical formula, the dynamic meshing force of the gear pair and the dynamic load distribution coefficient to calculate and obtain the tooth surface wear loss of the gear pair. According to the gear pair abrasion loss prediction method based on the dynamic meshing force, prediction efficiency and prediction precision are both considered.

The invention discloses a method for calculating the time-varying meshing rigidity of a spur gear considering the influence of temperature. Considering the influence of the working environment temperature (steady state environment temperature) of the gear pair, the instantaneous temperature of the tooth surface generated by the friction heat of the driving wheel / driven wheel is calculated according to the Coleman theory, and the mathematical expression of the tooth surface contact temperature changing with time is derived. The results show that the contact temperature of the driving wheel / driven wheel is higher than that of the driven wheel. The thermal deformation of the tooth profile of the driven wheel and the driven wheel caused by the change of the tooth surface contact temperature iscalculated, and the temperature stiffness of the tooth caused by the change of the temperature is calculated. Finally, the time-varying meshing stiffness of gears is calculated according to the theory of rigidity series and parallel, combined with the bending stiffness, shear stiffness, axial compression stiffness, contact stiffness, tooth base stiffness and temperature stiffness of gears.

Provided is a peeled-off gear meshing model based on meshing stiffness. Force conditions of peeled-off gear teeth in gear engagement is considered, and a meshing process is divided into three phases, and meshing stiffness of the peeled-off gear teeth in the three meshing phases is respectively calculated. Defects of an existing peeled-off gear model that just two kinds of conditions of a peeled-off meshing region and a non-peeled-off meshing region are considered are overcome. In the model, influence of the root of gear teeth is considered, and a gear tooth is equivalent to a cantilever bam on a root circle, and peeled-off gear meshing stiffness is accurately calculated, and precision is improved, so the more accurate peeled-off gear meshing model is established. The model actually and accurately reflects a meshing process of a peeled-off gear, and the model can be effectively applied in dynamics modeling research of peeled-off gears.

The invention relates to a straight gear meshing stiffness calculation method considering complex matrix and crack propagation, and the method comprises the steps: obtaining an overall flexibility matrix of a driving wheel and a driven wheel of a meshing gear based on a finite element theory, and determining an overall flexibility matrix of a possible contact point at each meshing position; Introducing a nonlinear Hertz contact theory, and calculating a contact flexibility matrix of possible contact points at each meshing position; And introducing the overall flexibility matrix, the contact flexibility matrix and the initial gap vector of the possible contact point into a deformation coordination equation, and calculating the meshing stiffness of the meshing position. According to the method, crack propagation paths obtained through fracture mechanics can be considered at the same time, and the influence of a complex matrix structure (including a web structure and a lightening hole structure) on the meshing rigidity of the straight gear can be considered at the same time. According to the method, the straight gear meshing stiffness considering the gear web structure, the lighteninghole structure and the crack propagation path can be calculated at the same time. The result of the method is verified by adopting a three-dimensional contact finite element method, and the result shows that the method disclosed by the invention has higher precision for calculating the meshing stiffness of the crack-containing complex matrix gear.

The invention discloses a method for calculating the time-varying meshing stiffness of an internal meshing gear pair of a straight-tooth cylindrical gear. The method comprises the following steps thatS1, single-tooth meshing stiffness of an inner gear and an outer gear in a straight-tooth cylindrical gear inner meshing gear pair is calculated on the basis of a potential energy method; S2, the single-tooth meshing stiffness of the inner gear and the outer gear is converted into a function about the angular displacement of the outer gear according to the geometrical relationship; And S3, whether the stage of gear pair meshing is single meshing or double meshing is judged through gear angular displacement, and the time-varying meshing stiffness value of the inner meshing gear pair of the straight-tooth cylindrical gear is calculated on the basis of the stiffness series-parallel theory. On one hand, the blank of a time-varying stiffness calculation method of the gear under internal meshing at the present stage can be made up, and on the other hand, solving can be simplified and the calculation efficiency can be improved by combining gear geometric information on the basis of giving play to the high-precision advantage of an analytical method.

The invention provides an analyzing method of time-varying mesh stiffness of a single roller enveloping worm gear pair and aims to acquire the time-varying mesh stiffness of the single roller enveloping worm gear pair. The method includes: deducing worm tooth bending stiffness, shear stiffness and radial compression stiffness formulas; calculating worm tooth base stiffness; calculating worm gear tooth bending stiffness and shear stiffness; calculating worm gear tooth base stiffness; calculating worm stiffness and worm gear stiffness at a disperse contact point; calculating contact stiffness; performing serial and parallel calculation on the worm stiffness, the worm gear stiffness and the contact stiffness; calculating the time-varying mesh stiffness. The method has the advantages that the time-varying mesh stiffness of the single roller enveloping worm gear pair can be calculated, the worm gear stiffness and the worm stiffness can be further decomposed, the worm tooth bending stiffness, shear stiffness and radial compression stiffness formulas are provided, a calculation model of the number of meshing worm gear teeth in a mesh cycle is provided, and the method is applicable to the dynamic performance analysis and optimization design of the single roller enveloping worm gear pair.

The present invention discloses a planetary gearbox sun gear gradient pitting corrosion time-varying meshing stiffness analysis method and belongs to the dynamic modeling and signal analysis field. According to the planetary gearbox sun gear gradient pitting corrosion time-varying meshing stiffness analysis method, with an easily-damaged sun gear in a planetary gearbox adopted as an object, the pitting corrosion of the sun gear is divided into an early pitting stage and an extended pitting stage according to gradient pitting corrosion on the teeth of the sun gear; a calculation method of the time-varying meshing stiffness of the sun gear during a pitting fault is inferred on the basis of a potential energy law and according to the stress and deformation of the gear caused by pitting of different levels; and on the basis of the calculation method, the dynamic characteristic and vibration response of gradient pitting corrosion can be precisely analyzed. The method of the present invention can be applied to the dynamics research of other gearboxes of which the structures are similar to that of the sun gear.

The invention discloses a helical gear time-varying mesh stiffness calculating method based on finite element analysis, and belongs to the field of gear transmission system dynamics optimization design. How to calculate the helical gear time-varying mesh stiffness in a high precision and high efficiency mode in the prior art is the problem needing to be solved. According to the helical gear time-varying mesh stiffness calculating method, elastic deformation is analyzed by building a finite element model, gear single-tooth mesh stiffness is calculated through an ISO method, and accordingly, helical gear mesh stiffness is obtained; the helical angle value range and the gear width value range are not limited, the high-precision helical gear time-varying mesh stiffness can be calculated, and the reference is provided for gear dynamics theory and application perfecting, gear vibration reduced, noise reduction, gear modification and other aspects.

The invention discloses a method for dynamically correcting and calculating the meshing stiffness of a straight gear under a fluctuation load working condition, and belongs to the technical field of mechanical dynamics. The method comprises the following steps: synthesizing time-varying meshing stiffness of a transmission gear pair in a gear transmission system under a constant load working condition by using an energy method, calculating average meshing stiffness of each pair of gear pairs, substituting the average meshing stiffness into a bending-torsion coupling model of the gear transmission system, and loading an external fluctuation load to solve transverse vibration and torsional vibration responses of the system; analyzing the influence of transverse vibration and torsional vibration responses on the actual meshing state of each transmission gear pair under the fluctuation load working condition; and the straight gear meshing stiffness under the external fluctuation load working condition is dynamically corrected. The method has the advantages that the actual meshing state of the straight gear pair is reflected more truly; different from a traditional straight gear meshingstiffness calculation method, the method considers that the center distance, the meshing angle and the coincidence degree of a meshing gear pair are changed instead of being constant, and the method is closely related to the vibration state of a driving wheel and a driven wheel.

The invention provides a cracked gear-tooth meshing stiffness calculation method. According to the method, firstly, a precise gear model is established by means of the Solid Works. After that, the stress distribution of cracked gear teeth is solved out based on the finite element solution. Then a curve is drawn along a region of the gear teeth wherein the stress is widely distributed. With the above curve as a boundary, an effective thickness of the gear teeth with the occurrence of cracks is defined. According to the above novel method, the effective thickness is introduced into the calculation on the meshing stiffness of the cracked gear teeth. Meanwhile, with the integration of the rigidness of faulted gear teeth and the rigidness of faultless gear teeth, the stiffness variation diagram over the entire meshing period can be figured out. The effective thickness of the gear teeth is defined by the curve instead of a widely applied straight line. Compared with the conventional straight line-based meshing stiffness calculation method, the above method is higher in accuracy. The meshing stiffness calculation accuracy of the above method is also proved.

The invention discloses a tooth surface dynamic load distribution calculation method, relates to the technical field of dynamic analysis, and couples error-considered gear pair meshing stiffness and comprehensive meshing error calculation with system dynamic model solution so as to construct a tooth surface instantaneous contact and system vibration bidirectional feedback coupling dynamic model. ANewmark numerical integration method and a fixed point iteration method are combined to solve the coupling kinetic model, and therefore tooth surface dynamic load distribution considering errors at different rotating speeds is obtained. According to the method, the tooth surface transient contact and system vibration coupling dynamic model is established on the basis of a tooth surface bearing contact analysis method, and a more scientific and reasonable theoretical basis is provided for revealing a nonlinear coupling action mechanism of tooth surface transient contact characteristics and system vibration.

The invention relates to a method for analyzing a meshing characteristic of a gear pair. Based on the finite element model, the method for analyzing the meshing characteristic of the gear pair adoptsthe analytical method to analyze whole deformation and local contact deformation of the gear pair, and can the time-varying meshing stiffness and the bending stress of tooth roots. The method avoids nonlinear contact iteration and has higher computational efficiency and higher computational accuracy. The method can consider addendum modification, extended meshing contact and complex tooth bases ofa spur gear pair.

The method for quickly calculating the time-varying meshing stiffness of the helical gear pair under the actual working condition comprises the following steps: firstly, calculating the length of a contact line on gear teeth participating in meshing in the helical gear at a certain moment according to the overlap ratio of the helical gear under the specific working condition and the meshing position of the helical gear pair at the certain moment, therefore, each gear tooth participating in meshing in the helical gear pair at the moment is decomposed into countless independent straight tooth slices with the same thickness along the tooth width direction; calculating the meshing radius of a straight tooth slice on the end surface of the helical gear pair at the moment; calculating the meshing stiffness of all straight tooth slice meshing pairs of each gear tooth participating in meshing in the helical gear pair at the moment by considering the gear pair displacement coefficient, the overlap ratio and the like, and calculating the meshing stiffness of each meshing gear tooth of the helical gear pair at the moment and the total meshing stiffness of the helical gear pair; and finally, by analogy, calculating the meshing stiffness of the helical gear pair at each discrete moment under the actual working condition, thereby quickly calculating the time-varying meshing stiffness of thehelical gear pair under the actual working condition.

The invention discloses a method for solving the time-varying meshing rigidity of a planetary gear based on an improved energy method. In the case of considering the relationship between a base circleand a tooth root circle, the invention establishes an improved cantilever beam model considering the deformation of a wheel body by taking 42 teeth as a limit. The time-varying meshing stiffness of each pair of planetary gears is discussed. Based on the consideration of gear deformation, the potential energy method is used to solve the more accurate time-varying meshing stiffness of gear teeth, and compared with the traditional potential energy method. The accuracy of the method is verified by comparing the results with those of finite element method.

The invention discloses a multi-data acquisition FZG gear box test device capable of adjusting meshing rigidity. The device comprises a test supporting seat, a test gear box, a motor supporting plateand a trial gear box are arranged at the top of the test supporting seat, and a driving motor is arranged at the top end of the motor supporting plate. The center distance is changed through a gap adjusting mechanism, so that the gear backlash is changed, the meshing rigidity of the test gear box is changed, the gear backlash of the gear is located under the critical compensation gap, when the gapworks, the rigidity of the gear is not affected by external loads, and the gear can stably work due to the fact that the rigidity is stably changed and does not change suddenly, the accuracy of testdata is ensured. By arranging multiple groups of temperature sensors and vibration sensors in the gear box and integrating data to be transmitted to the data acquisition system, the measurement of a real-time temperature field in the operation process can be increased, a basis is provided for calculating a gear transient temperature field, and meanwhile, the data acquired by the test has diversity; and wide popularization in scientific research is facilitated.

The invention provides a method for controlling anisotropic vibration of a torsional vibration shaft system. The mechanism of the torsional vibration and anisotropic vibration of shaft system mainly explains that the reason of generating anisotropic vibration is that symmetric branch structures exist in the torsional vibration shaft system and is provided with a plurality of same inherent frequencies, in the corresponding modes of vibration with same inherent frequencies, the amplitudes of the symmetrical structures are far greater than that of other parts of the torsional vibration shaft system. A method of implementing specific control measure is that the torsional vibration shaft system is designed to be a nonsymmetrical torsional vibration structure, so that different torsional dampers can be configured for the torsional vibration shaft system, and the inertia or torsional rigidity can be changed. In order to guarantee that the system is provided with enough torsional strength and the weight is not increased, the shapes of parts of same weights can be changed to obtain different inertias, so that the anisotropic vibration of the torsional vibration shaft system can be conveniently and effectively controlled. In a concentric symmetric gear system, a load regulating method is adopted to change the meshing stiffness so as to change torsional rigidity, so that the inherent frequency of the anisotropic vibration is adjusted to achieve an aim of controlling the anisotropic vibration.