Atomically precise gears

Types of atomically precise gears

Single atomic row gears

This has been modeled and MD simulated with rows of sulfur atoms as teeth.
See page: Examples_of_diamondoid_molecular_machine_elements#Gearbox

Suspicion: When heavily overloaded things might bend ans teeth may slip.
Likely no damage beside loss of position reference (loss of machine phase information).
Thus merely a need for re-homeing.

Multi atomic row gears

Multiple rows deep.
Smooth & precise running may be difficult to guarantee.
Case to case analysis needed.

Especially if the base axle is not high rotational symmetry by some means of structural bending.
(strained shell structure or by bond topology bent structure or by atom size bent structure)
but is rather low symmetry, and the teeth work off from that low symmetry
then the resulting structure can become very crude.
A bit like old wooden interlocking peg transitions in wheat mills.
This is probably not desirable in good well designed systems.

Classical gear tooth profile approximating gears

Quasi amorphous structures can approximate classical hear teeth profiles (evolvents, cycloids) a bit larger scales.
In some cases graphene sheet lining may be an option to get more smooth outer surfaces.
It may introduce flex between tack on points though.
As of 2025 no one has tried to even theoretically model such things yet.

Meshing gears that act as pumps

Related are Progressing cavity pumps (PCPs) as …

• PCPs too will need quasi amorphous structures and
  
• PCPs feature full and unbroken cycloid profiles.

PCPs are basically helical gear pairs with a spur gear running in a ring gear with one more tooth.
These meshing gear design choice just happens to make closed progressing chambers with enough of helical twist.
And these chambers can be used to pump gasses and liquids in a positive displacement pump fashion.
Thus PCPs can act as vacuum pumps avoiding the need for high speeds as needed in turbomolecular pumps.
And compared to piston pumps the rotative reciprocative wobble is better compensatable and there are fewer parts.

Vice-versa the pumped medium could actually act as coolant for the meshing pair being used as a gearbox.
Albeit duet to viscosity nos scaling well for the nanoscale this may be more reserved for at least microscale versions or bigger.
Not so much for the nanoscale.

Related

• Atomically precise bearings
• Periodic table of gearbearings
• Machine elements, List of machine elements

---

• Friction in gem-gum technology, Friction
• Superlubricity
• Mesoscale friction

---

• Absence of wear in atomically precise bearings

---

• Generalized gears