Idiot question: Why can't you use a cv axle as a driveshaft?

[tacoma2002]

Why do Freight Trucks that weigh 10X+ more than cars have driveshafts instead of solid shafts with more torque?
I was going to make the same conclusion, then I thought about stake trucks and Uhauls.

What? Maybe you misread my post.

They don't have solid shafts. They have drive shafts. As torque increases so does the size of the shaft. They're all hollow...

 

[White Stripe]

Can any of it be related to safety? i.e. during a severe impact the hollow driveshaft will collapse and not penetrate the passenger compartment, whereas a solid one would likely come up and penetrate the passenger compartment (and perhaps a few passengers?)...ouch.

No nothing to do with safety it's just a mechanical design.

 

[Hornd]

A Tube is stronger then a solid rod.

What? Maybe you misread my post.

They don't have solid shafts. They have drive shafts. As torque increases so does the size of the shaft. They're all hollow...

You said:

"Drive shafts don't need the strength that axle shafts have...plain and simple"

With your logic, all Large Trucks should have Axle Shafts.

Corvettes make 3X the power of a Land Cruiser and they use a Solid Shaft to drive the front wheels.

Maybe it comes down to length & angle vs Torque that determines application of each.

 

[Hornd]

No nothing to do with safety it's just a mechanical design.

Your logic is sound with steering linkage, but I have never heard of a driveshaft penetrating the passenger cabin. This may be due to the fact that it would need to make it pass the transaxle/differential which is no small hunk of metal.

 

[mct75]

I thought that all the forces tend to be on the outside of the cylinder, thus adding metal in the center was a waste of weight. Kinda like how high power RF feedlines are copper pipes.

At any rate, I'm more curious about the joints on the end instead of the tube/rod itself. However, if there was a way to buy a COTS CV axle and use it as a drive shaft that would be cool too! I don't know what application would be long enough for an 80, but maybe it could be lengthened?

 

[tacoma2002]

A Tube is stronger then a solid rod.


You said:

"Drive shafts don't need the strength that axle shafts have...plain and simple"

With your logic, all Large Trucks should have Axle Shafts.

Corvettes make 3X the power of a Land Cruiser and they use a Solid Shaft to drive the front wheels.

Maybe it comes down to length & angle vs Torque that determines application of each.

Not my logic at all.

I've never seen a 4wd Corvette?

Drive shafts can be hollow because the torque on them isn't as great as torque on the axle shaft.

That's my logic...