Analysis of tooth stiffness of nutation face gear

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Guangxin Wang ◽  
Lili Zhu ◽  
Peng Wang

Purpose The purpose of this paper is to obtain the single-tooth stiffness, single-tooth time-varying meshing stiffness and comprehensive meshing stiffness of the internal and external face gears and to analyze the influence of the modulus, pressure angle and tooth width of each face gear on the single-tooth stiffness of the gear in nutation face gear transmission. Design/methodology/approach From the point of view of material mechanics, the gear teeth of nutation face gear are simplified as spacial variable cross-section beams. The shear deformation of gear teeth, the bending deformation of tooth root and the additional elastic deformation caused by the base deformation are gotten by simplified trapezoidal section method, thus the stiffness of nutation face gear teeth can be obtained. The comparison with finite element method results verifies the rationality of simplified trapezoidal section method for calculating the tooth stiffness of nutation face gear. Findings The variation of stiffness of internal and external face gears along the meshing line and tooth height in nutation face gear transmission is studied, and the variation laws of single tooth stiffness, single-tooth-pair mesh stiffness and single tooth time-varying meshing stiffness of nutation face gear teeth are obtained. Originality/value Nutation face gear transmission is a new type of transmission. The stiffness of face gear teeth is analyzed, and the variation rules of single tooth stiffness, single-tooth-pair mesh stiffness and single tooth time-varying meshing stiffness of nutation face gear teeth are obtained, which not only enriches the research of nutation face gear transmission but also has important guiding significance for the application of nutation face gear in engineering practice.

2013 ◽  
Vol 834-836 ◽  
pp. 1273-1280
Author(s):  
Ze Hua Hu ◽  
Jin Yuan Tang ◽  
Si Yu Chen

The periodic and chaotic dynamic responses of face gear transmission system considering time-varying mesh stiffness and backlash nonlinearity are studied. Firstly, a nonlinear time-varying dynamic model of face gear pair is developed and the motion equations are presented, the real accurate mesh stiffness is obtained by applying Finite element approach. Then, the dynamic equations are solved using Runge-Kutta numerical integral method and bifurcation diagrams are presented and analyzed. The stability properties of steady state responses are illustrated with Floquet multipliers and Lyapunov exponents. The results show that a process of periodic-chaotic-periodic motion exists with the dimensionless pinion rotational frequency as control parameters. The analysis can be a reference to avoid the chaotic motion and unstable periodic motion through choosing suitable rotational frequency.


2013 ◽  
Vol 135 (7) ◽  
Author(s):  
Zehua Hu ◽  
Jinyuan Tang ◽  
Siyu Chen ◽  
Duncai Lei

The effect of mesh stiffness on the dynamic response of face gear transmission system combining with backlash nonlinearity is studied. First, a nonlinear time-varying (NLTV) and a nonlinear time-invariant (NLTI) dynamic models of face gear transmission system with backlash nonlinearity are formulated. The 6DOF motion equations of the face gear pair considering the mesh stiffness, backlash, contact damping and supporting stiffness are proposed. Second, the effect of mesh stiffness on the dynamic response of the face gear drive system is analyzed with the numerical method, where the mesh stiffness is expressed in two patterns as time-varying form and time-invariant form. According to the comparative study, some significant phenomena as bifurcation, chaos, tooth separation and occurrence of multijump are detected. The results show that different forms of mesh stiffness generate an obvious change on the dynamic mesh force.


2003 ◽  
Vol 56 (3) ◽  
pp. 309-329 ◽  
Author(s):  
Jianjun Wang ◽  
Runfang Li and ◽  
Xianghe Peng

In this paper, the progress in nonlinear dynamics of gear driven systems in the past twenty years is reviewed, especially the gear dynamic behavior, by considering the backlash and time-varying mesh stiffness of teeth. The basic concepts, the mathematical models and the solving methods for the non-linear dynamics of geared systems are then reviewed. The critical issues for further research on the nonlinear vibration in gear transmission systems are also discussed. There are 204 references cited in this review article.


Symmetry ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 609
Author(s):  
Lingli Cui ◽  
Tongtong Liu ◽  
Jinfeng Huang ◽  
Huaqing Wang

This paper investigates the effect of a gear tooth peeling on meshing stiffness of involute gears. The tooth of the gear wheel is symmetric about the axis, and its symmetry will change after the gear spalling, and its meshing stiffness will also change during the meshing process. On this basis, an analytical model was developed, and based on the energy method a meshing stiffness algorithm for the complete meshing process of single gear teeth with peeling gears was proposed. According to the influence of the change of meshing point relative to the peeling position on the meshing stiffness, this algorithm calculates its stiffness separately. The influence of the peeling sizes on mesh stiffness is studied by simulation analysis. As a very important parameter, the study of gear mesh stiffness is of great significance to the monitoring of working conditions and the prevention of sudden failure of the gear box system.


2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Faysal Andary ◽  
Joerg Berroth ◽  
Georg Jacobs

This study introduces a new potential energy-based design method for simplifying elastic gear bodies in low- to mid-range frequency applications by bridging over the gear teeth with external stiffness elements. The advantage of the introduced method over more traditional approaches, which are either based on rigid gears or on replacing the teeth, is that the complex gear body and its dynamic behavior are preserved, albeit with fewer degrees of freedom. The method is demonstrated on a gear by replacing a single tooth under load and then validated numerically against a typical flexible gear model. The simulation results show good accuracy within the chosen frequency range and with a clear reduction in calculation time compared to the unreduced model. Furthermore, the extension and optimization potential of the results is discussed.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Duncai Lei ◽  
Xiannian Kong ◽  
Siyu Chen ◽  
Jinyuan Tang ◽  
Zehua Hu

Purpose The purpose of this paper is to investigate the dynamic responses of a spur gear pair with unloaded static transmission error (STE) excitation numerically and experimentally and the influences of the system factors including mesh stiffness, error excitation and torque on the dynamic transmission error (DTE). Design/methodology/approach A simple lumped parameters dynamic model of a gear pair considering time-varying mesh stiffness, backlash and unloaded STE excitation is developed. The STE is calculated from the measured tooth profile deviation under the unloaded condition. A four-square gear test rig is designed to measure and analyze the DTE and vibration responses of the gear pair. The dynamic responses of the gear transmission are studied numerically and experimentally. Findings The predicted numerical DTE matches well with the experimental results. When the real unloaded STE excitation without any approximation is used, the dynamic response is dominated by the mesh frequency and its high order harmonic components, which may not be result caused by the assembling error. The sub-harmonic and super-harmonic resonant behaviors are excited because of the high order harmonic components of STE. It will not certainly prevent the separations of mesh teeth when the gear pair is under the condition of high speed and heavy load. Originality/value This study helps to improve the modeling method of the dynamic analysis of spur gear transmission and provide some reference for the understanding of the influence of mesh stiffness, STE excitation and system torque on the vibration behaviors.


Author(s):  
Xinpeng Hu ◽  
Xi Wu ◽  
Jixin Wang ◽  
Jim Meagher

Although tremendous effort has been applied to develop reliable strategies for detecting tooth cracks of gearboxes, these methods have generally fallen short of the required performance. Cracks are usually initiated at the root of a tooth and are very difficult to be identified from time-domain measurement. The vibration signal transformed by wavelet is sensitive to energy change. In this study, the transient vibration variations induced by different sizes of cracks at the tooth root are captured using wavelet. Firstly, as the main parametric excitation, the time-varying gear meshing stiffness caused by the alternating of engaged gear teeth is accurately calculated based on energy method, in which comprehensive deformations including Hertz contact, axial compression, bending, shearing and fillet-foundation deflection are taken into consideration. Moreover, a sophisticated dynamic theoretical model is used to simulate a practical gear system. Unique vibration signatures are captured through the comparison of cracked and perfect gear system.


Author(s):  
Jing Wei ◽  
Shaoshuai Hou ◽  
Aiqiang Zhang ◽  
Chunpeng Zhang

Abstract Time-varying mesh stiffness (TVMS) is one of the important internal excitations of gear transmission systems. Accurate solution of meshing stiffness is the key to research the vibration response of gear transmission system. In the traditional analytical method (TAM), the TVMS of single-teeth engaged region consist of bending, shearing, axial compression deformation stiffness, fillet-foundation stiffness, and Hertzian contact stiffness, the TVMS of double-tooth engaged region is the sum of the single-tooth engaged region, which will lead to repeated calculation of the fillet-foundation stiffness. In order to overcome this shortcoming, considering the coupling effect between two pairs of meshing tooth, an improved method of fillet-foundation is adopted to calculate to TVMS of each slice gear. According to the ‘slicing method’, the helical gear is divided into slice gear. Considering the coupling effect of each slice gear, the TVMS of helical gear can be obtained. The improved analytical method (IAM) is verified by comparing with finite element method (FEM) and TAM. Based on the IAM, the effects of the helical angle, face width, the number of gear, and modification coefficient on the mesh characteristics are analyzed. The results show that the IAM is consistent with the FEM and also consistent with TAM in single-tooth engagement. However, there is obviously error with the TAM in double-tooth or multi-tooth engagement.


2018 ◽  
Vol 211 ◽  
pp. 17002
Author(s):  
Guanghu Jin ◽  
Wei Ren ◽  
Rupeng Zhu

A dynamic model of power split transmission system with face gear and cylindrical gear is established. The factors including time-varying mesh stiffness, torsional stiffness, supporting stiffness, and clearance are considered in the model. The influence of the torsional stiffness of compound gear shaft on the load sharing coefficient is analyzed. The results show that the influence of the torsional stiffness of the compound gear shaft is obvious. Because the torsional stiffness of the output gear components is larger and the torsional stiffness of the input gear is smaller, so the input stage's deformation coordination ability is strong. Therefore, with the increase of the torsional stiffness of the compound gear shaft, the load sharing coefficient of the power input stages is improved, but the load sharing coefficient of the split torque stages and power confluence stages is worse. Hence, the torsional stiffness ratio of the transmission shaft should be rationally allocated under the condition that the torsional stiffness of the compound shaft is small.


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