How about instead of a physical-contact gear meshing, a magnetic meshing by permanent magnets?
4-layer & 6-layer PCBs and more: https://www.pcbway.com
Artillery Sidewinder X2: https://tidd.ly/3ueWsPg
Discount code(-$49): HEKKA3DX2

Magnetic gears has an engagement that is completely non-contact through magnetic forces, which gives them many advantages, such as much quieter(!) and lubrication-free operation.