Difference between revisions of "Suitable mechanisms"

Revision as of 16:22, 17 May 2023

This page is basically just a list of mechanisms that
could be useful for future advanced diamondoid gemstone based nanosystems.

Unlike in macroscale machinery with machine parts at the lowermost possible size limit
there is no space for tiny screws that are much more tiny than the parts (housings like gearboxes and such) to clamp together.
Thus there is a need for designs that differ quite a bit from the conventional.
See the design principles listed on the page: RepRec pick-and-place robots (GemGum).

Under the lens of these constrains a particular set of
mechanisms/machine-elements emerges as especially promising.
This page is a collection of such mechanisms.

These mechanisms also allows for interesting 3D printable mechanics that
can cope without any metal screws whatsoever. A few big 3D printable screws suffice.

Related

• Gear-bearings. Peculiarly the periodic table of gearbearings
• The design principles listed on page RepRec pick-and-place robots (GemGum)

External links

Bearings and Gearings

• conical/tapered gearbeaings
• conical/tapered ravigneaux gearboxes: https://www.flickr.com/photos/65091269@N08/51163799216
• Wobblemotors: Moineau PCP pumps run partially in reverse with the core only rotating and the outside only wobbling
• PCP gearboxes
• ( Coupled cycloid wobble-rotors like this: https://twitter.com/Kuu3_Mechanics/status/1657680117680979969 – 9,10,11,12 )

Couplings

• https://en.wikipedia.org/wiki/Coupling#Oldham
• Oldham coupling inspired gear coupling
  Two linear-rack-gearbearings with each two rollers sandwiched atop each other.
  Their rolling direction is are arranged 90° to each other. Thus they act the same as an Oldham coupling. But with rolling rather than sliding.
• (Schmidt coupling - this needs a lot of pins (ideally gear-bearings) thus listed in the likely unsuitable section further below)

Joints

• Hirth joints: https://en.wikipedia.org/wiki/Hirth_joint
• Spline joints: https://en.wikipedia.org/wiki/Spline_(mechanical)

• fir-tree joints (generalization/optimization of dovetail joints) https://en.wikipedia.org/wiki/Dovetail_joint
• rotate extruded fir-tree-joints allowing for torsion or bending around a virtual axis

For quick-release:

• Panic snap: https://en.wikipedia.org/wiki/Panic_snap
• Snap shackle: https://en.wikipedia.org/wiki/Shackle

Joints are useful for:

• self centering
• positive locking
• connection by form closure

Chains

• Sprockets: https://en.wikipedia.org/wiki/Sprocket
• Roller chains: https://en.wikipedia.org/wiki/Roller_chain
• Gear teethed chains
• Attachment chains
• Rigid chains: https://en.wikipedia.org/wiki/Rigid_chain_actuator

For end-effectors and preceding

• Chucks https://en.wikipedia.org/wiki/Chuck_(engineering)
• Parallel plane fast acting grippers
• Vise like grippers: https://en.wikipedia.org/wiki/Vise

• Whippletree: https://en.wikipedia.org/wiki/Whippletree_(mechanism)
• Classical mechanical differential (for robot wrists): https://en.wikipedia.org/wiki/Differential_(mechanical_device)
• SCARA geomerty: https://en.wikipedia.org/wiki/SCARA
• Parallel manipulator: https://en.wikipedia.org/wiki/Parallel_manipulator
  The general principle. Not just the given example. Parallel SCARA, CoreXY, ... all parallel.
• successive onion shell peel-off tube-axle and bevel-gear serial mechanics principle

Special screwdrivers end-effector mechanisms that:

• put zero torque on the manipulated structure ("space screwdriver")
• decouple tensioning from unloaded screwing structure ports (wiki-TODO: explain that principle more clearly with sketch)

These screwdrivers end-effector mechanisms shall operate on "tension-force hydrants".
See ReChain frame systems.

Likely useful for tensioning and other things

• Turnbuckle: (but rather for length adjustment when load is displaced) https://en.wikipedia.org/wiki/Turnbuckle
• Differential screws: https://en.wikipedia.org/wiki/Differential_screw

• Rolamite (but modified to gearbearings): https://en.m.wikipedia.org/wiki/Rolamite

Positive displacement pumps

• PCP pumps: https://en.wikipedia.org/wiki/Progressing_cavity_pump
• conventional piston pump: https://en.wikipedia.org/wiki/Piston_pump
  but operated like described on page vacuum handling
• ( Roots blower: https://en.wikipedia.org/wiki/Roots-type_supercharger )

Probably too many small pins, too low stiffness, and better solutions present

• Sarrus linkage: https://en.wikipedia.org/wiki/Sarrus_linkage
• Paucellier linkage: https://en.wikipedia.org/wiki/Peaucellier%E2%80%93Lipkin_linkage
• Schmidt coupling: https://en.wikipedia.org/wiki/Schmidt_coupling