Impact of V-apex misalignment in herringbone gears on transmission performance and measurement

To accurately predict the axial vibration displacement of herringbone gears and control their manufacturing quality. Focusing on herringbone gears for aircraft engines, this research developed a finite element method-based approach to predict axial vibration displacement accounting for alignment deviations, and subsequently measured the deviations. First, the geometric characteristics of the V-apex of the herringbone gear and its deviation were characterized using the concept of tooth flank characteristic lines and V-iron, and a mathematical model of the tooth surface including this deviation was constructed. Secondly, a geometric model and FEA model of a herringbone gear considering the V-apex deviation were established, thereby investigating the influence mechanism of this deviation on the static-dynamic behaviors of aircraft herringbone gear drive trains. Finally, methods for measuring the axial alignment deviation of the V-apexes were proposed, and the alignment deviation was evaluated with experimental verification through precision measurement tests. Research shows that: The axial alignment deviation had a direct impact on the load distribution and the axial vibration of the herringbone gear system, and the total axial alignment deviation F A = 0.0221 mm. This study furnishes systematic theoretical support for the low-vibration optimization design and processing quality control of herringbone gears used in aircraft propulsion systems.