Transmission Design of Bevel Gear with Arbitrary Crossed Axes and Its Application in the Knotter

The bevel gear transmission with crossed axes is widely used, but there are the difficulty of tooth profile calculation and modeling in the design and manufacturing process. This paper analyzes firstly the parameter solving equation of the bevel gear pair with arbitrary crossed axes. Based on the meshing principle of the bevel gear pair and numerical analysis method, the meshing equations of the bevel gear pair with crossed axes are derived, which provide the calculation models for the design of spatial bevel gear tooth surface. Taking the bevel gear pair with crossed axes in two kinds of the knotter as two design examples, the geometric parameters of the bevel gear pair in the knotter are solved, and the mathematical models of the tooth surface are programmed and calculated by using MATLAB. Through the graphic display of the tooth surface point set under MATLAB software and the 3D modeling function of Pro/Engineering software, the accurate 3D models of the bevel gear tooth surface are established. The meshing transmission simulations of the established bevel gear pair are respectively carried out by using ADAMS, and their physical prototype and transmission tests are also implemented. The test results showed that the transmission of the designed bevel gear pair is accurate and stable, which proves the correctness of the derived calculation model of the tooth surface of the bevel gear with crossed axes.

Social nudges for vaccination: How communicating herd behaviour influences vaccination intentions

Objectives: This Registered Report attempted to conceptually replicate the finding that communicating herd immunity increases vaccination intentions (Betsch, et al., 2017, Nat. Hum. Behav., 0056). An additional objective was to explore the roles of descriptive social norms (vaccination behaviour of others) and the herd-immunity threshold (coverage needed to stop disease transmission).Design: An online experiment with a 2 (herd-immunity explanation: present vs. absent) x 3 (descriptive norm: high vs. low vs. absent) x 2 (herd-immunity threshold: present vs. absent) between-subjects fractional design.Methods: Sample consisted of 543 people (aged 18–64) residing in the United Kingdom. Participants first received an explanation of herd immunity emphasising social benefits (protecting others) in both textual and animated-infographic form. Next, they were faced with fictitious information about the disease, the vaccine, their country’s vaccination coverage (80% or 20%), and the herd-immunity threshold (90%). Vaccination intention was self-rated.Results: Compared to the control, communicating social benefits of herd immunity was effective in increasing vaccination intentions (F(1,541) = 6.97, p = .009, Partial Eta-Squared = 0.013). Communicating the descriptive norm or the herd-immunity threshold alongside the herd-immunity explanation demonstrated no observable effect.Conclusion: Communicating social benefits of herd immunity increased self-reported vaccination intentions against a fictitious disease, replicating previous findings. Although this result is positive, the practical relevance may be limited. Further research into the effect of social nudges to motivate vaccination is required, particularly with respect to the recent pandemic context and varying levels of vaccine hesitancy.