Generative Designed Crankshaft

[dren]

https://www.autodesk.com/customer-stori ... aft-design

This is pretty wild looking.

[gruntguru]

WOW. 50% lighter and yet you can see the strength. I wonder what engine that crank is designed for? Not many engines with 3 main bearings these days.

Crankshaft has not been a focus area for weight saving because the flywheel effect is somewhat useful (this crank will need a slightly heavier flywheel).

No counterweights.

What are the two lugs near the flywheel end?

[J.A.W.]

I'd doubt it has been designed for a practicable* engine, as such.

Most likely a bit of 'blue sky' Honda R & D 'dreamwork', hence its open reveal.

* Bearing journal diameter/width ratio appears too large for realistic rpm, given stroke.

(Could the extra bracketry be a mount for some kind of (not revealed) crank balancer?
Certainly the output flange seems quite hefty for a weight-reduction engineering exercise).

[dren]

That's my guess, some sort of dampener on the output end. I'm assuming this is for a relatively low rpm steady state ICE hooked to a generator. It's a design study either way, but interesting what they computer came up with.

[saviour stivala]

50% lighter for a road going 4 in-line by reverting to just 3 mains, good exercise in designing a lighter crank. An exercise in lightness which there is no hope of achieving for a formula one crankshaft.

[e36jon]

https://www.3dnatives.com/en/honda-3d-p ... 0320205/#!

Figured a few more views might help.

[dash1]

Just wow! Looks great.

[Greg Locock]

It hasn't got crank webs so they can get the journals on, but it would be a pretty useless crankshaft without counterweights. Perhaps the oversized bearings can accommodate the high inertial loads... or maybe clickbait doesn't care.

[vorticism]

MGA crank with similar shapes. Why is it lacking counterweights? (on the OP)

[Greg Locock]

I count two big counterweights and 2 small ones. 3 mains 4 big ends, I wonder if we'll go back to that for fuel consumption? Not being a bearingologist I wonder if you get more friction from 3 big mains or 5 smaller ones?

[vorticism]

Sorry I meant on the original post example. Although you speculated their tall/narrow bearings may tolerate inertia loads. It looks quite small judging by the guy holding it; maybe a motorcycle or kei car 4-cyl. Otherwise a low RPM genset motor as suggested above? With less concern for balance.

It's amusing; knocking off the counterbalances and then claiming a 50% weight reduction. Did they need a computer for that?

[J.A.W.]

Member here 'Manolis' showed a design "Pattakon VRA" which embodied an inertia torque device,
one which that Honda crank might utilize, per the unoccupied bracketry nearest the PTO flange?

See via link below:

http://www.pattakon.com/pattakonVRA.htm

[Tommy Cookers]

1960s etc UK Ford made their future around millions of engines 3 mb engines 1000cc-1500cc with common bore
thousands of FJunior & F3 & touring car race wins - courtesy of Cosworth etc etc
then switched to 5 mb for commonality with (same bore centres) 1100 - 1600cc
iirc the 1100 (and 1300 ?) was able to use cheaper bearing material and cheaper journal surface quality
the MG shown etc etc had uneven bore spacings - presumably unhelpful to the crankshaft design


https://www.triple-mregister.org/forums ... IC_ID=8138
2 main bearings anybody ?
as the sv Austin 7 (even supercharged) and sv & ohc Morris Minor and ohc MG (even supercharged) had till c.1934
the introduction of valve overlap was under consideration by Austin and Morris in those days

of course only these special competition crankshafts had any counterbalancing
notice the Austin one is 2 piece -to allow it to be installable in the crankcase (roller bearing and minimal)
international class ie 'world' speed records were set this way
the 750 MC book told us to allow for pistons 2 and 3 having greater travel (giving variable compression)
I say (was it tried ?) excess centre counterbalance could aid crankshaft survival - but generate a midstroke vibration

the 'good old' British motorcycle engines were 2 mb (twin cylinder)
one Norton had a common bore size and 250 - 400 cc capacity
apparently the 250 cc version was originally intended to be cheap by having an integral iron head/cylinder casting
the valve seats being accessible for machining from below
could the head, 'cylinder block', and 'crankcase' be cast as one piece ?
with this or an Austinish type of engine ?

[J.A.W.]

1960s etc UK Ford made their future around millions of engines 3 mb engines 1000cc-1500cc with common bore
thousands of FJunior & F3 & touring car race wins - courtesy of Cosworth etc etc
then switched to 5 mb for commonality with (same bore centres) 1100 - 1600cc
iirc the 1100 (and 1300 ?) was able to use cheaper bearing material and cheaper journal surface quality
the MG shown etc etc had uneven bore spacings - presumably unhelpful to the crankshaft design


https://www.triple-mregister.org/forums ... IC_ID=8138
2 main bearings anybody ?
as the sv Austin 7 (even supercharged) and sv & ohc Morris Minor and ohc MG (even supercharged) had till c.1934
the introduction of valve overlap was under consideration by Austin and Morris in those days

of course only these special competition crankshafts had any counterbalancing
notice the Austin one is 2 piece -to allow it to be installable in the crankcase (roller bearing and minimal)
international class ie 'world' speed records were set this way
the 750 MC book told us to allow for pistons 2 and 3 having greater travel (giving variable compression)
I say (was it tried ?) excess centre counterbalance could aid crankshaft survival - but generate a midstroke vibration

the 'good old' British motorcycle engines were 2 mb (twin cylinder)
one Norton had a common bore size and 250 - 400 cc capacity
apparently the 250 cc version was originally intended to be cheap by having an integral iron head/cylinder casting
the valve seats being accessible for machining from below
could the head, 'cylinder block', and 'crankcase' be cast as one piece ?
with this or an Austinish type of engine ?

Funnily enough, the loud-piped/high-comp/big-carb/fat-cammed Norton Commando 750 'Combat'
variant in 1972 suffered from main-bearing failures due to its 'ropy' crankshaft flexing under the powerband encouraged by its 'Isolastic' chassis vibration suppression system, & only received 'barrel'
type roller 'Superblend' mains when warranty claims were cruelling Norton as a performance brand.

Incidentally, the 1972 Kawasaki 750 triple used the same sized mains as the Norton, but used a
1/2 dozen mains to support its crankshaft, even though it was revving no higher - despite being
markedly over-square with a stroke of 63mm - compared to the Norton's 89mm...

[johnny comelately]

There is a crankshaft in there that may be of interest
(Really need to be able to copy paste images into here)

https://cdn-ddcfa.nitrocdn.com/JQYfXJOB ... -parts.jpg