What would be the simplest mechanical way of combining two deflections of two cogs into a deflection in another cog?
Eg over here there is an external torque being applied to a rod that deflects it by 30 degrees, over there is an external torque being applied to a rod that deflects it by 22 degrees, and we want this to cause a deflection in a third rod of 52 degrees, by gears or some other mechanical means.
A differential.
Kingy said:
A differential.
Were diffs around before cars?
The first description of a device which could integrate differential equations of any order was published in 1876.
https://en.wikipedia.org/wiki/Differential_analyser
apologies for loss of some formatting
https://en.wikipedia.org/wiki/Differential_(mechanical_device)
There are many claims to the invention of the differential gear, but it is possible that it was known, at least in some places, in ancient times. Confirmed historical milestones of the differential include:
100 BC–70 BC: The Antikythera mechanism has been dated to this period. It was discovered in 1902 on a shipwreck by sponge divers, and modern research suggests that it used a differential gear to determine the angle between the ecliptic positions of the Sun and Moon, and thus the phase of the Moon. c. 250 AD: Chinese engineer Ma Jun creates the first well-documented south-pointing chariot, a precursor to the compass that uses differential gears to discern direction rather than a magnet. 1720: Joseph Williamson uses a differential gear in a clock. 1810: Rudolph Ackermann of Germany invents a four-wheel steering system for carriages, which some later writers mistakenly report as a differential. 1827: modern automotive differential patented by watchmaker Onésiphore Pecqueur (1792–1852) of the Conservatoire National des Arts et Métiers in France for use on a steam wagon. 1832: Richard Roberts of England patents “gear of compensation”, a differential for road locomotives. 1874: Aveling and Porter of Rochester, Kent list a crane locomotive in their catalogue fitted with their patent differential gear on the rear axle. 1876: James Starley of Coventry invents chain-drive differential for use on bicycles; invention later used on automobiles by Karl Benz. 1897: first use of differential on an Australian steam car by David Shearer. 1958: Vernon Gleasman patents the Torsen dual-drive differential, a type of limited-slip differential that relies solely on the action of gearing, instead of a combination of clutches and gears.dv said:
What would be the simplest mechanical way of combining two deflections of two cogs into a deflection in another cog?Eg over here there is an external torque being applied to a rod that deflects it by 30 degrees, over there is an external torque being applied to a rod that deflects it by 22 degrees, and we want this to cause a deflection in a third rod of 52 degrees, by gears or some other mechanical means.
I’m no expert, but wouldn’t that be just sun and planet gears rather than a differential?
Sun and planet gears look like this:
A differential has bevelled gears and looks like this:
Wouldn’t mind knowing what kind of mechanism Williamson used.
Electromagnetic viscous coupling, anybody?
dv said:
What would be the simplest mechanical way of combining two deflections of two cogs into a deflection in another cog?Eg over here there is an external torque being applied to a rod that deflects it by 30 degrees, over there is an external torque being applied to a rod that deflects it by 22 degrees, and we want this to cause a deflection in a third rod of 52 degrees, by gears or some other mechanical means.
Too early in the morning for me, can you draw a quite picture of that please?
You’ll get extra points for colouring withing the lines.
Rule 303 said:
Electromagnetic viscous coupling, anybody?
How does that work? Like a reversible laminar Couette flow?
mollwollfumble said:
Rule 303 said:
Electromagnetic viscous coupling, anybody?
How does that work? Like a reversible laminar Couette flow?
Picture spinning plates with oil between them. The oil is full of iron filings, so that when electricity is applied to one plate, an electromagnet is created and the plates bond.
I was thinking that a really low-tech and clunky way to do it would be to use pulleys
dv said:
I was thinking that a really low-tech and clunky way to do it would be to use pulleys
Spiny Norman said:
dv said:
What would be the simplest mechanical way of combining two deflections of two cogs into a deflection in another cog?Eg over here there is an external torque being applied to a rod that deflects it by 30 degrees, over there is an external torque being applied to a rod that deflects it by 22 degrees, and we want this to cause a deflection in a third rod of 52 degrees, by gears or some other mechanical means.
Too early in the morning for me, can you draw a quite picture of that please?
You’ll get extra points for colouring withing the lines.
yeah need a picture
get out your favorite crayon, dv
Rule 303 said:
mollwollfumble said:
Rule 303 said:
Electromagnetic viscous coupling, anybody?
How does that work? Like a reversible laminar Couette flow?
Picture spinning plates with oil between them. The oil is full of iron filings, so that when electricity is applied to one plate, an electromagnet is created and the plates bond.
Thanks, got the picture.
> I was thinking that a really low-tech and clunky way to do it would be to use pulleys
I know that that has to work, because anything that can be done with gears can be done with pulleys. But how to arrange the pulleys to make a differential engine?
