Steerable, Inboard shaft drive?

[powerabout]

I seen off road CV joints handle 850 HP and 42" tall tires or thousands of miles. BUT I said new high angle joint not CV joint!! I started with 4340 and 300m BUT I can get unotanium it's call Domex. It will need seals and lube. is that the best you can do?

OCB

How big are they?

 

[whitepointer23]

A stern-drive is a steerable propshaft . Can't accuse volvo of not thinking outside the box.

 

[FAST FRED]

"Interesting Fred but please expand the explanation on the offset the engine and shaft 3deg solution."

The concept is the prop blades that are in the deepest water are also in the densest.

So offsetting the engine and drive shaft a few deg can compensate for the prop walk.

The Atkin site has many power boats shown with this feature , take a look.

 

[BMcF]

I seen off road CV joints handle 850 HP and 42" tall tires or thousands of miles. BUT I said new high angle joint not CV joint!! I started with 4340 and 300m BUT I can get unotanium it's call Domex. It will need seals and lube. is that the best you can do?

OCB

The tricky bit you've maybe skipped: In most applications, CV and Double-cardan joints are only required to handle torque, not thrust (high axial load). Complicates the situation just a bit.

 

[OCB]

How big are they?

3 1/8 in it's round.

 

[OCB]

Puller prop

A stern-drive is a steerable propshaft . Can't accuse volvo of not thinking outside the box.

Reverse inboard V drive is one of my best ideas. I will need a prop hub to deal with the 3 1/8 joint IMO.

 

[OCB]

The tricky bit you've maybe skipped: In most applications, CV and Double-cardan joints are only required to handle torque, not thrust (high axial load). Complicates the situation just a bit.

The axial and shock loads with a 42" 200 pound tire comes to a sudden stop brings very high axial loads IMO.
Pfaff racing Huntington beach Ca. used Series 30 CV joints to get over the motors in off shore racing boats.

 

[BMcF]

The axial and shock loads with a 42" 200 pound tire comes to a sudden stop brings very high axial loads IMO.
Pfaff racing Huntington beach Ca. uses Series 30 CV joints are used get over the motors in off shore racing boats.

I've built and raced offroad trucks, including mug boggers with 44" tires, as a hobby for about 25 years..in the interest of full disclosure. Gave it up back in 2004 after an accident in my MX Bronco put me out of the drivers seat forever.

But how are large axial loads created in axle or drive shafts of a truck? The source of radial loads is obvious, of course.

I am aware of at least one marine CV joint product that can take - is designed to take - full propulsion thrust loads. Used them in a couple yacht projects, in fact. But they are completely inside the vessel and are fixed in place;

http://www.aquadrive.com/

Might also be worth a good look at how the gimbal on the Arneson surface drives is made...since they are a steerable shaft drive device.


As an aside, we've (my marine engineering company) recently been requested to help with the development of an advanced vessel concept that requires a "retractable" propeller shaft line and to do that will almost certainly require a submersible CV joint capable of reacting bot the axial (thrust) and radial (torque) from the engine.

 

[OCB]

I've built and raced offroad trucks, including mug boggers with 44" tires, as a hobby for about 25 years..in the interest of full disclosure. Gave it up back in 2004 after an accident in my MX Bronco put me out of the drivers seat forever.

But how are large axial loads created in axle or drive shafts of a truck? The source of radial loads is obvious, of course.

I am aware of at least one marine CV joint product that can take - is designed to take - full propulsion thrust loads. Used them in a couple yacht projects, in fact. But they are completely inside the vessel and are fixed in place;

http://www.aquadrive.com/

Might also be worth a good look at how gimbal on the Arneson surface drives is made...since they are a steerable shaft drive device.


As an aside, we've (my marine engineering company) recently been requested to help with the development of an advanced vessel concept that requires a "retractable" propeller shaft line and to do that will almost certainly require a submersible CV joint capable of reacting bot the axial (thrust) and radial (torque) from the engine.

BMcF,

Sorry to hear about your accident, I started in the off-road scene in the mid 80's mudding Azuza canyon Ca. I had Bronco with a Big Block Ford, 44" tires, 60/14 bolt rear. Now I have a TY Jeep with IFS/IRS, LS3 480HP , Atlas, 10" TT ring gears. I have been working with some of the top TT, Dakar, ultra 4 teams.
I have seen and researched the Aquadrive, The low max angle on the Aquadrive won't do the job . I have seen the the gimble on the Arneson surface.
I think the thrust load is one of the things that will need to addressed.
BMcF if you are interested talking more about your "retractable" development project please send me a pm.

 

[Barry]

"Interesting Fred but please expand the explanation on the offset the engine and shaft 3deg solution."

The concept is the prop blades that are in the deepest water are also in the densest.

So offsetting the engine and drive shaft a few deg can compensate for the prop walk.

The Atkin site has many power boats shown with this feature , take a look.

Thanks, I was not sure which direction the offset was and what was trying to be achieved

 

[tom kane]

Steerable,Inboard shaft drive

We just need a cv joint made from unobtanium so it can take the load and run underwater without any seals or lubrication

Why on earth would you want to run anything in salty water when you can put it safely inside the boat.

Some old outboards had open lower bear boxes with no oil and were water lubricated, new material may make that possible.
I discovered that and old outboard in my collection had been run with no grease/oil in the box for quite a while and showed little damage.

 

[tom kane]

Steerable,Inboard shaft drive

Thanks, I was not sure which direction the offset was and what was trying to be achieved

If you build a boat that has motor or anything offset or different you can guarantee that it will be pointed out to you that it is not in the right place or does not "look" right.
Asymmetric design has many practical advantages, it could have prevented the deaths of many powerful WW2 fighter pilots because of the high rotational torque involved.

 

[OCB]

High axial load

The tricky bit you've maybe skipped: In most applications, CV and Double-cardan joints are only required to handle torque, not thrust (high axial load). Complicates the situation just a bit.

My new joint will do high Axial loads.

I forgot to correct my answer on post # 19 before posting #24 .

OCB

 

[tom kane]

You can combine standard adjustable thrust bearings in a conventional inboard shaft drive with C/V joints and also twin U/V joints with a spline and that gives you a Retractable shaft drive if you make provisions for the propeller shaft to be raise or lowered. There are many ways to build a retractable shaft adjustable from the helm.

 

[powerabout]

Why on earth would you want to run anything in salty water when you can put it safely inside the boat.

Some old outboards had open lower bear boxes with no oil and were water lubricated, new material may make that possible.
I discovered that and old outboard in my collection had been run with no grease/oil in the box for quite a while and showed little damage.

Low load /rpm stuff you can get away with lots of fudges.