Sensitivity predictions of geometric parameters on engagement impacts of face gear drives

Face gear dynamics is one of study focuses of face gear drives, and addressed by many scholars. However, an engagement impact force calculation solution of face gear drives is not to be constructed, and some design suggestions for face gear drives considered engagement impact effects are also not to be extracted. Thus, in this study, an engagement impact force calculation solution of face gear drives is constructed, and a conversion solution between engagement impact energy and static transmission errors is proposed. Furthermore, based on a four DOF dynamic model formulated, the dynamic behavior difference of face gear drives between without and with engagement impacts is simulated, and sensitivity predictions of geometric parameters on engagement impacts are discussed. According to the limited analytic results in the issue, some design suggestions for face gear drives associated with lower engagement impacts are obtained. These contributions should improve the design of face gear drives in the future

Constructed solutions of face gear dynamics associated with engagement impact energy decay

Face gear drives are focused by many researchers, due to several strong-points versus traditional spiral bevel gear drives. However, calculation solutions of face gear dynamics associated with engagement impact energy decay are not to be constructed, according to the limited published issues. Thus, in the study, a calculation solution of engagement impact energy decay of face gear drives is proposed, a face gear dynamic model is established, and the dynamic mesh forces of an example case of face gear drives without engagement impacts as well as with engagement impacts and engagement impact suppressions are simulated. The results indicate the fidelity of the proposed calculation solutions of face gear dynamics associated with engagement impact energy decay could be accepted. These contributions would improve the developments of face gear drive modifications and engineering applications of face gear drives in the future

Analytical impact of the sliding friction on mesh stiffness of spur gear drives based on Ishikawa model

Mesh stiffness always is a studying focus of gear dynamics. In the issue, a solution for the calculation of mesh stiffness considering the sliding friction effect is constructed, and the influence of the sliding friction on mesh stiffness is analyzed. Further, the analytical results indicate mesh stiffness is sensitive to the sliding friction in poorly lubricating conditions specially. These contributions would not only simplify the calculation of mesh stiffness associated with the sliding friction but also be good for assessing the dynamic behaviors of spur gear drives in some special operating condition

Calculation of static transmission errors associated with thermo-elastic coupling contacts of spur gears

The static transmission error is one of the key incentives of gear dynamics and addressed by many scholars. However, the traditional calculation method of static transmission errors of spur gears does not take into account the influence of thermo-elastic coupling caused by the gear temperature field, and it limits the accuracy of the dynamic characteristic analysis. Thus, in this study, the calculation method of static transmission errors associated with thermo-elastic coupling is proposed. Furthermore, the differences between static transmission errors associated with thermo-elastic coupling contacts and traditional method of gear is discussed. The study is helpful to improve the accuracy of dynamic analysis of gear transmission system

Differences of dynamic behaviors of face gear drives between time varying and average mesh stiffness

Face gear dynamics is one of important studies of face gear drives. However, differences of dynamic behaviors of face gear drives between time varying and average mesh stiffness are not to be discussed. Thus, in this study, a mesh stiffness calculation solution of face gear drives is constructed, which is based on the proposed equivalent face gear teeth, and a four DOF dynamic model of face gear drives is formulated. Furthermore, differences of dynamic behaviors of face gear drives between time varying and average mesh stiffness are investigated. The result indicates instantaneous impacts are existed at start engagement points of face gear drives

Solutions of active vibration suppression associated with web structures on face gear drives

Vibration suppression of face gear drives is always one of study focuses of face gear dynamics. Thus, in the study, a solution of active vibration suppression associated with web structures on face gear drives is proposed, and an example case of face gear drives associated with the proposed solution is simulated. The results indicate effects of the proposed solution on face gear dynamic behaviors are significant. These contributions would benefit to improve face gear vibration suppression studies

Effect predictions of star pinion geometry phase adjustments on dynamic load sharing behaviors of differential face gear trains

Face gear drives, which are suggested to be used in input stage gear drives of helicopter main gear boxes, are focused by many scholars. However, differential face gear trains, which can be employed in output stage gear drives of coaxial helicopter main gear boxes, are not to be addressed by researchers, and dynamic load sharing design solutions of differential face gear trains are yet to be investigated. Thus, in the study, a star pinion geometry phase adjustment solution, which is not to change drive ratios of differential face gear trains versus traditional geometry parameter adjustment solutions, is proposed, and a six DOF torsion dynamic model associated with four star pinions is established. Furthermore, dynamic load sharing behaviors of two version differential face gear trains are discussed, and the effects of star pinion geometry phase adjustments on two version differential face gear trains are predicted. The analytic results indicate the effects of the proposed star pinion geometry phase adjustments on dynamic load sharing behaviors of two version differential face gear trains are significant. These contributions would benefit to improve dynamic load sharing designs and engineering applications of differential face gear trains in the future

An improved mesh stiffness calculation model of spur gear pair under mixed EHL friction with spalling effect

Based on the “Potential energy method”, the improved mesh stiffness calculation model of spur gear pair with actual involute and transition curve is proposed. Furthermore, the spalling effect, nonlinear contact stiffness, improved fillet-foundation stiffness, time-varying friction coefficient under mixed elasto-hydrodynamic lubrication (EHL) condition are assimilated into the model. Then the results of the improved mesh stiffness model are obtained by numerical simulation, in which the mesh stiffness under mixed EHL friction and the effect of height for spalled area on the mesh stiffness are comprehensively investigated

Nonlinear dynamic analysis of GTF gearbox

Considering multiple nonlinear parameters, a nonlinear dynamic model of star gear-rotor-bearing transmission system of GTF (Geared Turbofan Engine) gearbox is established. The dynamic responses are obtained through Runge-Kutta numerical integration method, and the responses with the variation of input rotational speed are analyzed and illustrated. The abundant nonlinear characteristics are presented in the results, which could be guidance to avoid undesirable nonlinear motion, and provide a reference for the design and control of the transmission system in GTF gearbox

Construction of 12 DOFs spur gear coupling dynamic model

A 12-degree-of-freedom (DOF) spur gear dynamic model is constructed, which is coupled by the mesh gear pair and the gearbox. The construction method of spur gear coupling dynamic model, based on lumped mass method, is better than finite element method, due to higher modeling efficiency. The work would be benefit to spur gear coupling dynamic modeling and analyses