Deformation and meshing stiffness analysis of cracked helical gear pairs

Planetary gearboxes are extensively used in mechatronic applications due to their compactness and high reduction ratios. The complex kinematic of such systems and the requirement of low-vibration-gears suggest studying these gearboxes with appropriate dynamic models. To this purpose, a planar lumped parameter model with 18 degrees of freedom was implemented. Model parameters such as the stiffness of the bearings and the gear meshes were calculated using dedicated FEM simulations. Two different gearbox configurations were simulated and experimentally tested. The compared results showed a good agreement. The main goal of the research was to assess the validity of such methodology for the prediction of the system eigenfrequencies. Additionally, from a kinematic analysis of the gearbox it was possible to individuate the self-excitation frequencies. The overlapping of these self-excited frequencies with the eigenfrequencies of the system was individuated as the major cause of the gearbox noise.

A mixed FEM and lumped-parameter dynamic model for evaluating the modal properties of planetary gearboxes

A hybrid analytical-numerical method based on Isogeometric Analysis for determination of time varying gear mesh stiffness

An improved mesh stiffness calculation model for cracked helical gear pair with spatial crack propagation path

Investigation on crack failure of helical gear system of the gearbox in wind turbine: Mesh stiffness calculation and vibration characteristics recognition

Time-varying gearmesh stiffness (TVGS) is the main cause of gear vibration, and its accuracy affects the responses of dynamic models. An exponential curve model based on the Saint Venant’s Principle is proposed to calculate the gearmesh stiffness of cracked spur gears in this paper. With the proposed model, the TVGS under the circumstances of healthy condition and four crack cases are computed, whose results have a good agreement with those of finite element method (FEM). Therefore, the exponential curve model can be used to estimate the TVGS and an alternative to FEM in gearmesh stiffness calculation is provided.

https://www.jvejournals.com/article/19139/pdf

A new model for calculating time-varying gearmesh stiffness

A gear pitting modeling method based on probability distribution comprises: first, establishing a tooth face probability pitting plane distribution model, with pitting randomly distributed along toothwidth and normally distributed along tooth height; second, acquiring meshing line length variation by means of image processing; third, establishing one-to-one correspondence relation between the meshing line length variation and pressure angle; fourth, comprehensively considering hertz contact stiffness, bending stiffness, shear stiffness and axial compression stiffness to precisely calculate gear time-varying mesh stiffness and solve internal excitation of a gear system. The gear pitting modeling method based on probability distribution has the advantages that the defects are overcome that,for instance, a traditional pitting model is greatly deviated from the actual and complex pitting distribution is unable to be handled; model calculation precision is improved; internal excitation ofa pitting gear system is precisely calculated; gear pitting modeling based on probability distribution is completed.

Lei Yaguo

Papers

A new model for calculating time-varying gearmesh stiffness

Gear pitting modeling method based on probability distribution