Application of Face-Gear Drives in Helicopter Transmissions

In order to solve the load-sharing characteristics of face-gear four-branching split-torque transmission system (FGFBSTTS), the static load-sharing mechanical analysis model was established. In the model, the deformation coordination conditions of torsional angle and torque balance condition were considered. By using Loaded Tooth Contact Analysis (LTCA) technology of face gear and herringbone gear, the time-varying meshing stiffness was calculated. The influences of manufacturing errors, installation errors, I-stage pinion floating, II-stage pinion spline clearance floating, and radial limit ring clearance floating on the load-sharing characteristics are analyzed. The results show that the LTCA technology is more accurate to reflect the load-sharing characteristics of each meshing position. When the I-stage pinion and the II-stage pinion floated at the same time, the best load-sharing characteristics can be obtained. The load-sharing characteristics affected by manufacturing errors showed obvious periodic change. The radial limit ring plays a better auxiliary role in load-sharing characteristics. The theoretical results were compared with the experiments to verify the correctness of the theoretical analysis. The research results can provide a theoretical basis for the optimal design of the load-sharing structure, error control, and assembly of the face gear four branch transmission system.

Section: Introductionmentioning

confidence: 99%

Study on the load-sharing characteristics of face-gear four-branching split-torque transmission system

Hao

Zhang

Zhao

et al. 2021

“…Face gear drives are a new type of gear transmission consisting of a cylindrical pinion and a conjugated face gear with the advantages of low noise, light weight and convenient installation compared with bevel gear drives. 1,2 When machining the face gear, according to the position relationship between the cutter and the machined face gear, the two axes can be divided into vertical intersection, non-vertical intersection, vertical staggered and non-vertical staggered for four types of situation. The corresponding face gears are called an orthogonal face gear, non-orthogonal face gear, offset orthogonal face gear and offset non-orthogonal face gear.…”

Section: Introductionmentioning

confidence: 99%

Modelling, design and analysis of offset, non-orthogonal and profile-shifted face gear drives

Fang

Cui

et al. 2018

This article proposes the application of a profile-shifted grinding disc to generate an offset, non-orthogonal and profile-shifted face gear. A detailed investigation of the modelling, tooth geometry and contact characteristics of the offset, non-orthogonal and profile-shifted face gear has been conducted. The mathematical models of the profile-shifted shaper cutter, profile-shifted pinion, profile-shifted grinding disc and offset, non-orthogonal and profile-shifted face gear are established. Considering the topological modification, the tooth surface equation of the offset, non-orthogonal and profile-shifted face gear is deduced. Based on the undercutting and pointing of the tooth surface, the limiting tooth width of the offset, non-orthogonal and profile-shifted face gear is determined, and a mathematical model of tooth contact analysis of the offset, non-orthogonal and profile-shifted face gear drive is established with the alignment errors. Using the approach presented in this article, an example of an offset, non-orthogonal and profile-shifted face gear drive and analytical results are presented.

“…Zanzi and Pedrero 7 probed the impact of modifications on TCA of face gear drives. According to study achievements of face gear drives, Litvin et al 8 suggested that face gear drives could be used in first-stage gear drives of helicopter main gear boxes. Due to high rotation speed characteristics of first-stage gear drives in helicopter main gear boxes, face gear dynamics becomes one of the study focuses of face gear drives.…”

Section: Introductionmentioning

confidence: 99%

Study of low-noise face gear drives associated with micro-punch webs

Chen

Zhu

2016

Face gear dynamics is addressed by many scholars. However, design solutions of low-noise face gear drives without gear tooth modifications are not to be constructed. Thus, in this study, a design solution of low-noise face gear drives associated with micro-punch webs is proposed. A calculation procession of geometric parameters of micro-punch webs is constructed, an example case of a micro-punch web for a low-noise face gear drive is calculated, which is based on the proposed calculation procession, and the noise elimination effect of the example case is predicted. Meanwhile, the impacts of geometric parameters of micro-punch webs on sound resonant frequencies are discussed. Furthermore, an experiment of the example case is conducted to check the effect of micro-punch webs on noise reductions and the proposed calculation procession and design solution. The experimental results indicate that the noise reductions of face gear drives can be accomplished by micro-punch webs under the almost same dynamic response conditions, and the fidelity of the proposed calculation procession of geometric parameters of micro-punch webs and design solution of low-noise face gear drives can be accepted. These contributions would improve engineering applications of low-noise face gear drives.