BALL SPLINE AXLES

[GEARS]

HERE ARE BALL SPLINE AXLE SHOTS.

[GEARS]

ON CAR

[ntsqd]

The splines themselves don't appear to be out of ordinary. Thot "Ball" meant the shape of the spline OD ?

Be interesting to see what their lifespan is. Those changes in cross section have got to shorten it up.

[KitRacer]

what kind of travel r u gettin??? did you gain travel with them???
whats all the details on these guys???
are these the same as John Markings????

[GEARS]

TRAVEL=28"

[GEARS]

YES,TRAVEL WAS GAINED.
USES A FIXED JOINT 70 DEG INCLUDED ANGLE,
THE AXLE DOSE ALL THE PLUNGE

[GEARS]

NO BALL REFERS TO THE BALL ROLLERS IN THE AXLE CANESTER THAT RIDE IN THE
SPLINED GROVE WITH IN THE CANASTER.

[GEARS]

THESE ARE ON MARKINGS AND ARE BUILT BY MCKENZIES,BUT
MENDEOLA HAS A SET BEING BUILT ALSO.

[FABRICATOR]

Think of several precision-ground longitudinal half-round grooves in both the inner and outer (or male and female) axle parts. Line these inner and outer grooves up to create a series of round holes. Fill each hole part way up with a bunch of bearing balls. Axle plunge causes the balls to roll in the grooves even while transmitting tremendous torque. This setup is very strong and durable. If you size them right, keep the dirt and water out and the lubrication in, the lifespan can be nearly unlimited. These have been around for industrial use for many decades and in limited automotive use since at least the sixties. A very close cousin to these can be found in most common worm-and-sector steering boxes (Saginaw, etc.) and ball screws in milling machines.

[ntsqd]

Yah, once it was explained that the balls were in the 'slip-yoke' I understood how it worked. Very much like a ball-type linear bearing except for no recirculation.

My comment about durability stems from the massive and seemingly awkwardly executed section changes in the shaft.

Someone in the Import Drag Racing spectrum has come up with a Ball shaped spline for use as a CV joint as they appearently keep blowing up CV's. Which is what piqued my interest when I saw this thread.

[BA_DirtDriver]

I think that they do recirculate. Or they could / should . How much plunge is required? What is the torque rating? I hope this works.

[GEARS]

no recirculation

[GEARS]

I hope this works also.

[GEARS]

pic

[GEARS]

pic *

[Raceworks]

Whoever did the Aluminum work in that car did a incredibl job.

[Mike_HKmtrsprts]

oh Ian's in trouble showing off John's top secret axels!!! LOL I talked with John today they arent ball type axels they are some crazy triagulated brass bushing type???, he tore them up 100 mi now they are changing some stuff inside and should be good to go for Henderson but the car acually get 26" of travel not 28" but hope fully the new design wont bind the cv up under load and the intenals of the axels will hold together!....Mike

[KitRacer]

has he been able to fix the problem with the car tryin to squat from all the horsepower?

[GEARS]

NOW THAT THE AXLES ARE CLOSER TO BEING,THE BACK HAS BEEN REDONE TO SIT HIGHER AND RIDE BETTER
THAN BEFORE.HORSEPOWER SITS IN THE HIGH 300 NOT THAT BIG OF A #.BUT POWER ISN'T
BEING ROBBED BY A CONVERTER.NOW LET SEE IF THE TIRES LIVE AT HENDERSON.

[partybarge_pilot]

All right, I gotta ask. Whats the deal with the twin stick shifter?

[BitorPerformance]

The car uses the mendeola sequential if i rember correctly the one on the right is for the reverse, the one on the left does the foward gears.pull to go faster push to go slower(i think) i asked that question at plaster city once a while back ago i could be wrong Ian for sure knows

[desertracer]

I thought Marking was getting way more than a high 300hp rating from his motor. Maybe I mis-read that, but could you let us know what type of motor he is running. That is a lot of car to push, he needs all the power he can get.

[michael_loomis]

the # 's i heard were 750hp + with a big PLUS

[Dave_G]

RE: "Be interesting to see what their lifespan is. Those changes in cross section have got to shorten it up."

Thom,
Not so much the change in cross section because there isn't much. The root diameter of the axle spline appears to be in perspective to the axle diameter. Where this type of setup will fail is the poor surface area contact between the ball and the axle spline and outer sleeve. On a round ball like that how wide do you think the surface area contact under torque load really is. Maybe .001 or less per ball?? What will probably happen is the balls will beat small dimples along the spline and not roll so swift after a period of time. A regular type axle spline has massive surface area contact for each tooth that's why it doesn't slip when the axle plunges. Drive shaft splines have the same problem when the rearend cycles up and down.

Dave

[ntsqd]

Dave, I'm looking at the outer sleave that has a significant & sharp step up from the nominal shaft diameter. I wouldn't expect the inner shaft to have much trouble.
Good point about the Brinnelling. I hadn't thot about it that far. Been a lot of distractions around here lately. Once the balls have started to make their divots their progression should be a flattening log curve (or nearly so) because the contact surface area will be increasing as the divot depth increases. Obviously, once there are divots the part is junk as a variable length device. Danged if you do or don't.

We need the air bearing equivelent of a spline for this application.

[Dave_G]

RE:"Danged if you do or don't."

Yep. There's no free lunch. I would imagine that the balls are made from 9310 and case hardened to about Rc 60-62. In order to keep the axle spline groove from brinnelling you'd need that to be in the same rockwell range. I just can't picture a shaft that sees a lot of torque being carburized to that hardness and living. The ideal axle material for maximum strength and cycles would be 300m or Maraging 300 but that stuff will only see a Rockwell of about 54 at best. Not hard enough to keep from Brinnelling.

Dave

[partybarge_pilot]

"brinelling"

Small tapered roller bearings.......................

[BA_DirtDriver]

henderson???

[ntsqd]

</font><blockquote><font class="small">In reply to:</font><hr />
Small tapered roller bearings.......................

[/ QUOTE ]

Self defeating. You'd actually want cylindrical, not tapered rollers. Now you've got line contact instead of point contact (which is better), but as you suggest the size of the rollers would have to be small which reduces the contact area. So you're essentially back where you started.

[FABRICATOR]

Actually, CV’s, ball bearings, and most gears only contact on a few thousands of an inch of surface area. These all have similar pressures applied to just as small an area. The key to longevity in every case is the rolling motion of the areas of contact and proper metalurgy. The ball spline is no more or less than a series of angular contact ball bearings. A single 2” angular contact ball bearing has a capacity of thousands of pounds of pure thrust load. As with most ball bearings, there is much more than a small point of contact at work. One example of ball contact area is the many split race ball bearings in use. These have a chamfered parting line right down the middle of the inner or outer race (usually not both) and work just fine. 36 balls should easily do the job. If this spline arrangement proves to be fast wearing it would be from metallurgy not contact area.

[ntsqd]

My point was that there would be no real gain in load bearing over round balls.

Something I should have said was that using cylindrical rollers makes making the parts much more difficult because now there is a roller alignment issue to deal with where all you needed for balls was a groove of the right size.

[Dirtracer]

any updates on these axles...did the bugs ever get worked out on them??

[Triaged]

http://www.race-dezert.com/forum/showpost.php?p=152192&postcount=22

[gawdodirt]

Think of several precision-ground longitudinal half-round grooves in both the inner and outer (or male and female) axle parts. Line these inner and outer grooves up to create a series of round holes. Fill each hole part way up with a bunch of bearing balls. Axle plunge causes the balls to roll in the grooves even while transmitting tremendous torque. This setup is very strong and durable. If you size them right, keep the dirt and water out and the lubrication in, the lifespan can be nearly unlimited. These have been around for industrial use for many decades and in limited automotive use since at least the sixties. A very close cousin to these can be found in most common worm-and-sector steering boxes (Saginaw, etc.) and ball screws in milling machines.

Great idea! Datsun Z axles used this in the 'Z' series for years. All the way into the 80's. Their achilles heal was that for mass production, they had to use ductile iron and that had material limitations. Also, the torsional load capacity was decreased due to static diameter.
Palmers Custom Speed tried to use multiple balls to increase the load surface. Again, the parent material had hardening limitations. Down side was that with increased surface load capacity/increase, there was an equal increase in friction that limited their free movement under loading. Dupont Krytox lube could've been the answer, but it is still very expensive.

No one tried a hard cylindrical plastic insert, that I know of. Or a friction coating like wrist pins on a cylindrical steel load roller and run them wet or submerged...

Glad to see the idea find a renewed interest.

GD

[gawdodirt]

Dave, I'm looking at the outer sleave that has a significant &amp; sharp step up from the nominal shaft diameter. I wouldn't expect the inner shaft to have much trouble.
Good point about the Brinnelling. I hadn't thot about it that far. Been a lot of distractions around here lately. Once the balls have started to make their divots their progression should be a flattening log curve (or nearly so) because the contact surface area will be increasing as the divot depth increases. Obviously, once there are divots the part is junk as a variable length device. Danged if you do or don't.

We need the air bearing equivelent of a spline for this application.

A precision ground and hardened spline alone would work with superior lube. Nascar has been using a round (ball) spline on their cambered axles for years. But again they use Krytox and have a known lifespan.

How expensive is it to grind an internal spline?!?? $$$$$$$$$$$$$$

GD

[mebuildit]

I like the idea of the shafts, I'll be curious to see the longevity of these.


I'm getting ready to pack my CV's and noticed that someone said use Krytox. What is the best grease to use? What are the best benefits to using krytox?

[Jess@HighAngle]

On grease- I have some neo -and at 350 degree's that's stuff turns to ash- but pro long sits in 550 degree's and does not lose its shape or go away- Jess

[gawdodirt]

What equipment did you use to measure drop point?

Or did you just let it sit on a hot piece of steel and measure the temp with an IR gun?

GD