Drive shaft angle

[xpensive]

...
Slight quibble with numbers (20mm sounds a bit shy, and the yokes of the UJ are significant, but a lot will be carbon not steel) - it is an oscillating torque, not an absolute torque decrement. The reason i said you'd be sad if you tried a 30 degree articulation on the UJ is that these high amplitude high frequency torques are actually enough to break things.

Perhaps so, but that's what engineers do when dealing with a potential problem. Please note that I doubled the estimated inertia and even if I had been one decimal off, the oscillating torque would still be zip in relation to the nominal 2200 Nm.

The 30 degree xample was obviously not mentioned in relation to an F1 application.

[PhillipM]

Nonsense. Many powerful RWD cars with pretensions of civility use CVs (typically tripod inboard, rzeppa outboard). I have a sneaking feeling that other than off roaders CVs rather than Hookes for the rear axle are in the majority.

CV's are a majority off road too!
Yokes don't take kindly to 30* of angle the associated plunge forces.

[Greg Locock]

Sorry, I've been wracking my brain thinking of an example where inertial intermediate forces have caused a durability problem, and I think I've over- egged that pudding. The usual problems with Hookes joints is that you can't maintain parallel input and output shafts. The speed variations then generated create large torques and they break things.

[Tommy Cookers]

Nonsense. Many powerful RWD cars with pretensions of civility use CVs (typically tripod inboard, rzeppa outboard). I have a sneaking feeling that other than off roaders CVs rather than Hookes for the rear axle are in the majority.

CV's are a majority off road too!
Yokes don't take kindly to 30* of angle the associated plunge forces.

either type of joint will accomodate angles or plunge/plunge forces that it's designed for, neither is special in this

CV joints were always designed for big angles (and plunge?) for FWD (typically Hooke type UJs weren't?)

Hooke UJ use always had the potential to generate noise/vibration (eg prop shafts)


so I can now see why many car makers use CVs in situations that could be covered (and were) by Hookes
(off-road tyres somewhat cushion the joints torquewise over road discontinuities, relative to tyres in the old days?)

and I stand informed


BTW surely with any type of joint a permanent 10 degree offset (as per the OP) is undesirable ? (for long term use)

[autogyro]

Of course one could always design a diff with bevel gear output to account for the base angle.
Just to add another aspect.

[hardingfv32]

Would that be a net benefit in your estimation?

Brian

[Tommy Cookers]

Of course one could always design a diff with bevel gear output to account for the base angle.
Just to add another aspect.

but there would still be the 10 deg on the outer joints ?


so no-one has thought of/heard of/ seen ? a negative camber 'live axle'(Hotchkiss drive, to be clear) ?

(just a bit of remachining reqd on a standard axle, including flexure functionality adequate for 2-3 deg neg camber?)

[Greg Locock]

I know of at least one live rear axle that was in production with a bit of toe in. No UJ required, the halfshaft bends, or the splines work like a cheap CV. Either way it got through durability!

[autogyro]

The bi-motor Alfa had two strait eight engines a central gearbox and a v drive, two drive shafts from the gearbox one to each rear wheel.
The shaft gearing on that worked well.
When looked at during a rebuild we realised that getting the engines lined up in the chassis was a major problem though.