Increasing bearing area to decrease friction: Difference between revisions
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Created page with " Unlike friction in macroscale bearings, <br> friction in atomically precise diamondoid slide bearings ... * is dominated by dynamic friction <br>(which scales quadratica..." |
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Friction in [[atomically precise diamondoid slide bearing]]s ... | |||
* is dominated by dynamic friction <br>which scales quadratically with speed: <br>1/2x speed => 1/4x friction | 1/10x speed => 1/100x friction | |||
* is proportional to the bearing area (2x area => 2x friction) | |||
For details see: [[Friction]] | |||
Side-note: <br> | |||
friction in | Low speed friction in macroscale bearings is quite different as it is <br> | ||
speed independent, area independent, load dependent. | |||
== The trick == | == The trick == | ||
| Line 10: | Line 13: | ||
* Halving speed and | * Halving speed and | ||
* doubling machinery | * doubling machinery | ||
(this keeps the total throughput constant) leads to | |||
* quartering friction losses due to reduced bearing speed | * quartering friction losses due to reduced bearing speed | ||
* doubling friction losses due to increased bearing area | * doubling friction losses due to increased bearing area | ||
| Line 16: | Line 19: | ||
'''Q:''' But isn't doubling the amount of machinery a problem? <br> | '''Q:''' But isn't doubling the amount of machinery a problem? <br> | ||
'''A:''' No! | '''A:''' No! There is exceptionally little machinery needed to <br> | ||
There is | |||
get practical levels of throughput (aka product production rate). <br> | get practical levels of throughput (aka product production rate). <br> | ||
This is to the [[scaling law]] of [[higher throughput of smaller machinery]]. | This is due to the [[scaling law]] of [[higher throughput of smaller machinery]]. | ||
=== Math === | |||
* P … (wearless) frictive losses – in W | |||
* A … bearing area – in m² | |||
* n … number of [[sub layers]] – an integer | |||
* v … speed of assembly … in m/s | |||
* gamma … dynamic friction coefficient – W/(m²*(m/s)²) | |||
<math> P = \gamma A n v^2 </math> <br> | |||
Applying the trick: <br> | |||
<math> P' = \gamma A (x n) (v/x)^2 </math> <br> | |||
<math> P' = \gamma A n v^2 /x </math> | |||
Related: [[Compenslow]] | |||
This has limits though! | |||
== Limits to the trick == | == Limits to the trick == | ||
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At some point assembly motions reach become similarly slow as the assembly motions. <br> | At some point assembly motions reach become similarly slow as the assembly motions. <br> | ||
At this point adding further [[sub- | At this point adding further [[sub-layer]]s there is no further reduction of frictive losses but rather frictive losses ride again. (eventually linearly). | ||
== Applications cases == | == Applications cases == | ||
| Line 38: | Line 57: | ||
== Related == | == Related == | ||
* '''[[Optimal sublayernumber for minimal friction]]''' | |||
* '''[[Deliberate slowdown at the lowest assembly level]]''' | |||
* [[Friction]], [[Superlubricity]] | * [[Friction]], [[Superlubricity]] | ||
* [[Infinitesimal bearings]] | * '''[[Infinitesimal bearings]]''' | ||
* [[Higher throughput of smaller machinery]] | * [[Higher throughput of smaller machinery]] | ||
* [[Mesoscale friction]] | |||
* [[Higher bearing surface area of smaller machinery]] | |||
[[Category:Surprising facts]] | |||
Latest revision as of 22:36, 29 March 2026
Friction in atomically precise diamondoid slide bearings ...
- is dominated by dynamic friction
which scales quadratically with speed:
1/2x speed => 1/4x friction | 1/10x speed => 1/100x friction - is proportional to the bearing area (2x area => 2x friction)
For details see: Friction
Side-note:
Low speed friction in macroscale bearings is quite different as it is
speed independent, area independent, load dependent.
The trick
This allows for a neat trick:
- Halving speed and
- doubling machinery
(this keeps the total throughput constant) leads to
- quartering friction losses due to reduced bearing speed
- doubling friction losses due to increased bearing area
Overall a halving of friction.
Q: But isn't doubling the amount of machinery a problem?
A: No! There is exceptionally little machinery needed to
get practical levels of throughput (aka product production rate).
This is due to the scaling law of higher throughput of smaller machinery.
Math
- P … (wearless) frictive losses – in W
- A … bearing area – in m²
- n … number of sub layers – an integer
- v … speed of assembly … in m/s
- gamma … dynamic friction coefficient – W/(m²*(m/s)²)
<math> P = \gamma A n v^2 </math>
Applying the trick:
<math> P' = \gamma A (x n) (v/x)^2 </math>
<math> P' = \gamma A n v^2 /x </math>
Related: Compenslow
This has limits though!
Limits to the trick
See math on main page: Limits to lower friction despite higher bearing area
- assembly motions can be slowed down by adding more sub layers.
- transport motions can not be slowed by adding more sub layers.
At some point assembly motions reach become similarly slow as the assembly motions.
At this point adding further sub-layers there is no further reduction of frictive losses but rather frictive losses ride again. (eventually linearly).
Applications cases
- This can be applied in the design of gem-gum on-chip factories to
optimize thickness of assembly layers of gem-gum factories
or just to get estimates for likely system geometries - This is the theoretical basis for infinitesimal bearings.