Cush drive unit

[artie on edge]

With regards to oil levels, I had intended running mine fairly high thinking that this would absorb and transfer heat to the housing better, your thoughts guys?

I know the more oil the more difficult it is to control (breather waste etc) but the short chain and the resultant heat is the issue, im thinking I may be in overkill mode here.

I also intended to use a 50/50 mix of hypoid gear oil and atf, this was common in the late 80's as fine mesh front wheel drive trans started to become common, again your thoughts as mine is old school thinking and there is most likely a better alternative.

My reasoning is the properties of the hypoid oil will reduce the highly loaded wear points and the atf will reduce foaming and oil escaping from the breather while giving a lower viscosity lubricant.

Incidentally Rick, as we are using the same bearings would this cad file be of use to you? [Or anyone else who wants it, drop me a line]


You may be able to mod to suit your needs, if so drop me a pm with your email address and ill zip it over to you.

[artie on edge]

IF you could go with a slightly larger sprocket why not make the sprocket in the above pics a simple sprocket mount? (remove the teeth and drill mounting holes) Then take common sprockets and machine out the center and drill it to bolt to the mount? One round cut on the new sprockets. Have spare handy easy.

Im with nutz here, mine are off the shelf items and flame hardened, probably never wear them out, cost was about $15 bucks aussie for the larger unit, its also oversized and its called (at least here in Oz) 10B size (sounds like a bra... more boobies.... ).

[fabr]

I'm of the mindset that ATF will be fine I could very well be wrong also.I used ATF in the first silent chain case I ran.No issues at all. 

[Admin]

I'm of the mindset that ATF will be fine I could very well be wrong also.I used ATF in the first silent chain case I ran.No issues at all.

Probbaly atf will be less likely to burp out the vent as well... I have a lot of gear lube blown out of the vent hole, and its at the top...

[artie on edge]

Thats why the blending, gear lube actually foams up (being thick it holds the bubbles introduced by the action of the gearset). ATF includes an anti-foam agent.

[Rick S.]

So I should toss this design in the trash and start over? .....Just kidding.

Thanks Artie, but I'm using type 4 cv's and I've got most of this modeled in UG at work.
I've been in UG training for about 3 weeks now. (1 1/2 days a week) The past couple of days I'm really getting the hang of it. This morning I modeled up everything that I have built here so far, and the bronze bushings. I'll post up some exploded views of everything next week. So far I'm really liking the UG program. The seat is expensive as hell, but my employer pays for it, so I'm not complaining.

I really don't think I'll wear this out. Especially if I never use it on a build.
I have zero $ into it so far (except time) and have WJ access as many sprockets a I need. Even the case hardening is at no cost to me. I'll just throw it in with other work items that we send out every week.
I was thinking about making a breather baffle. Similar to what Ive seen in a firearm suppressor. Also a small tube going high and then back to the bottom. This might help keep the oil from escaping through the breather.

[Rick S.]

Here's what I've modeled up so far. I got the Polyurethane rod today but I accidentally ordered the wrong dia. Not a bad thing because now I see that I'll want the harder 80 durometer. Seals and bronze for the bushings will be here this week too.
then it's on to the cv flanges. I'll ad these to the model after I turn them up.
I'm starting a model on my eccentric cv rear too. it's a snap to extrude the autocad dxf's in UG.

[SPEC]

Wow Rick  That looks great

[Boostinjdm]

How's the drive coming? 

[Rick S.]

It's on hold until I get out some other side work.
I have the bronze for the bushings and the bearings and oil seals.
I still need to order more polyurethane. I hope to turn the cv flanges and bronze flange bush'gs. within the next few weeks.

[Camel]

Excellent work Rick.  I like it.

[trojan]

Rick, how does the sprocket stay "true"?

[artie on edge]

Troj, im thinking that it will self align to a degree much like the cush drive on a bike (which normally uses rubber (well, my Duke does) and the hard duro of the cushion material should also hold it in alignment.

The fact that the chain is (or should be) perfectly aligned means it wont have a torsional bias at all. Near the ball park Rick?

[Rick S.]

Actually no.
the blue plates are doweled to the sprocket and the bronze flange bushings are pressed into the blue plates. The blue plate id's were opened up on the lathe with everything assembled and indicated between operations.
If you look closely at the grey drive gear you can see that it has a shallow pilot bored into each end. The model is missing the spacers that pilot into the grey drive gear. These spacers step up to 3" od and they are the surface that the bushings ride on.
The bronze bushings keep it true.
This is unlike the one that Yoshi posted the picture of.
That one actually relied on the fit of the housing and driver to keep everything running true.
It had no replaceable wear item like this design does.
Probably why the write up said it was important to keep it well greased.
That one wears on itself and eventually the entire unit would need to be replaced.

[Boostinjdm]

Damn it Rick, every time I go to make a suggestion, it dawns on me that you already thought of it.  I keep deleting the whole paragraph and then go back to staring at the pics.  I have a few suggestions I am keeping under my hat till you are finished though. I don't want to step on any toes.  Looks like what you got is working.  Am anxious to see finished product, case and all.