Direct Drive: Mechanical issues

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Direct Drive: Mechanical issues

Post by weber » Tue, 17 Feb 2009, 20:52

This topic branches off from approximately here.

viewtopic.php?p=9225&t=585#p9225

Here's what went before:
Johny wrote: Hi weber. Do you know how Ross overcame the problem of lubricating the rear oil seal (around the tail-shaft slip-yoke) without swamping the front motor bearing with oil? This is my current concern with using my tail-shaft housing. Sorry - a bit off topic here.
weber wrote: Not too off topic since one aim of many AC conversions is to eliminate the gearbox. But you can email me direct on d dot keenan at bigpond dot net dot au.

I have emailed him the question and will let you know. But I suspect he didn't solve it. I note, for others who may not be familiar, that the tail end of the gearbox of a front-engine rear-wheel-drive usually has a plain bearing that supports the front end of the propshaft (also called confusingly tailshaft or driveshaft in various countries) which is driven internally by a spline that allows for some misalignment. This plain bearing, and the spline, need lubrication, but you don't want your electric motor filling up with gear oil. 90 grade oil between rotor and stator could be a serious drag.

My own thoughts are to put gear oil into the tail casing, while on level ground, with the propshaft out, until oil just starts to run out the back, and rely on it moving about, as the car accelerates and goes up hills, to get it to the spline and plain bearing. And rely on the motors own oil seal to keep it out on the downhills and decelleration. Sounds a bit risky I admit.

If it did get into the motor, could it be flushed out with a solvent without disassembly?
Johny wrote: I'm impressed that you knew what I was on about. I agree it's too risky. One solution is to place a blanking plate halfway along the tail shaft housing and put yet another oil seal there. The problem may be trying to assemble it all.

My alternative is to NOT use the tail shaft housing and instead use an external slip-yoke as per a4x4kiwi's Electrolux (even my wife laughed at Mal's nickname for the Hilux).

Since AC motors are less expensive with only foot mount (as against foot and face mount) this is also cheaper (at least for the motor). It does require I get the motor as rear-ward as possible to not have an excessive length drive shaft - which is why I seek a 132 frame motor so that it fits in the transmission tunnel.

Anyway - the tail-shaft housing still has appeal if problems can be solved. I just happen to have a spare gearbox...

Hi Johny,

I agree that the problem with the blanking plate and additional oil seal is that the spline on the end of the output shaft is usually bigger than the shaft and so won't pull through the new oil seal. There may also be a speedo takeoff gear to consider.

Here's another idea, in the spirit of brainstorming: Drill a hole through the motor's oil seal (or face plate just below oil seal) and fit a tube so that any gear oil, that makes it past the motor's oil seal, drains outside.

Or an intermediate solution between the above two: Screw and seal a small housing to the motor face-plate, with an additional oil seal in it and a drain tube to outside. The housing could be a small aluminum cup or bowl or lamp reflector, or maybe even the lid off a pickle jar. No disassembly problem then, because it's part of the motor. Just have to make a seal where the drain tube comes out through the gearbox tail casing. Hmm. Maybe you need a tube in the top to let air in too, if it's a skinny drain tube with very viscous oil.

Sounds bad to just let it drip on the road, but there should be hardly any, and ICE's drip all the time. However you could have a trasparent plastic reserviour that you checked and emptied periodically. It would be interesting to see how much there was.

Something else that interests me is how to do the coupling from motor-shaft to sawn-off gearbox-output-shaft or other means of providing the spline coupling to the propshaft.

By the way, I've taken to using the British term "propshaft" for the long heavy thing with the two cardan universal joints, even though my dad taught me it was called the tailshaft when I was a little squib crawling under cars with him. That's because some folks in places other than Oz call the gearbox output shaft the tailshaft and some folks call a shaft between the diff and a wheel a driveshaft.

Coulomb and I are planning to do an AC MX-5 with no gearbox.

Ian Hooper essentially built an open frame replacement for his MX-5 gearbox tail, with a sealed bearing in it. It looks like a lot of work, and paying of professionals.

And you mentioned a4x4kiwi's Electrolux (great name Image). I found the relevant photos at

http://a4x4kiwi.blogspot.com/2008/08/mo ... alled.html

http://a4x4kiwi.blogspot.com/2008/08/driveshaft.html

http://a4x4kiwi.blogspot.com/2008/09/en ... alled.html

In this case, it looks like a lot of work modifying the propshaft.

We plan to use a 132 frame motor as well (most likely one of the new ABB ones, 15 or 18.5 kW). We'd love to put the motor right at the diff, like this one in Kim Ryan's Proton.

uploads/437/proton_EL_motor_to_diff_001.jpg

More on Kim Ryan's Proton in this thread:

viewtopic.php?t=851

The MX-5 has an unusual drivetrain mounting, in that it has a rigid beam (called the PPF or Power Plant Frame) connecting gearbox to diff. This beam runs along one side of the propshaft, while the exhaust pipe is on the other side. The whole setup is hung on only 4 rubber mounts, 2 at the engine and 2 at the diff which has "wings".

By putting the motor at the diff (a rear diff, unlike the Proton) we'd save the weight of the propshaft and PPF. But we'd need to find two solid points in the transmission tunnel to hang the 92 kg motor off, and the motor casing would need to be rigidly coupled to the diff casing by something other than the PPF (e.g. a short tube as in the Proton).

And some people think that the PPF is there not only to resist the gearbox/diff torque reaction, but to stiffen the body in reagard to the suspension's responds to uneven surfaces. So it sounds like it would be difficult to convince an engineer to approve a motor-at-the-diff construction.

The PPF normally attaches to the gearbox tail casing, so if we keep that, and of course the propshaft, it looks a bit easier. We'd still have to have something rigid going forward from the induction motor to the original ICE engine mounts.

Any ideas would be greatly appreciated.

-- weber

[Edit: Fixed yet another link broken by a dumb domain-name/directory-structure change by the forum administrators.]
Last edited by weber on Thu, 12 Jul 2012, 09:44, edited 1 time in total.
One of the fathers of MeXy the electric MX-5, along with Coulomb and Newton (Jeff Owen).

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Direct Drive: Mechanical issues

Post by Johny » Tue, 17 Feb 2009, 21:15

Thanks for starting the new thread.

OK on the terms - propshaft sounds fine.
I like the motor seal idea the most but it probably requires a face mount on the motor or at least not a rough cast front face on the motor.
It may be worth checking if sealed motor bearings are OK for this anyway - save a lot of work

Motor drive to sawn-off-gearbox-output-shaft (SOGOS).
How about this.
Have a coupling made for the motor drive to flat round plate - about 8 to 12cm diameter. Similar to a4x4kiwi's toothed plate (maybe the same for feedback). Then have a flat plate the same size welded to the SOGOS (professional welder required here). Make both with matching holes and bolt the two together. Hmmm. No room for bad alignment here but a good engineering shop should be able to do it.

I really do like the external slip-yoke especially if I don't have to extend my propshaft. I still haven't done the crawling-around-under-car measurements yet to see if the motor REALLY will fit in the tunnel - a lot revolves around that for me.

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Direct Drive: Mechanical issues

Post by fuzzy-hair-man » Tue, 17 Feb 2009, 22:02

I'm trying to stay with this discussion but having a bit of trouble...

So there's a bearing near the slip yoke at the rear of the ICE gearbox this is usually fed oil from the gearbox and is not usually a sealed bearing hence it needs oil.

You can't mount the shaft from the original gearbox (including the yoke) direct to the motor shaft and therefore have no need for the bearing at the rear of the gearbox? Isn't this what Mal's electrolux does?
Presumably you're worried it might stress the motors bearings too much causing failure? The motor bolted directly to the diff works because there's no propshaft stressing the bearings?

So if you were to do the SOGOS thing and replace the bearing with a sealed bearing? Ian's uses a sealed bearing right? I take it this what Johnny meant by "checking if sealed bearings are OK"

My other though was depending on the gearbox construction (sandwitch plate? I have the picture of a 1200 gearbox in my head) it might be possible to take the rear section of the gearbox housing off and replace the bearing with a sealed bearing then use the rear section of the gearbox to mount up to the motor. It might make a neat solution similar to Ian's open cage, if you were really lucky there might even be a mount on that part of the gearbox meaning one less engine mount you'd need to fabricate.Image

If you couldn't replace the bearing with a seal one perhaps you could seal up the rear section of the gearbox with another bearing and oil seal and fill the rear section of the gearbox with oil.

BTW Sorry if I entirely missed the point Image

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Post by weber » Tue, 17 Feb 2009, 22:16

But using the gearbox tail casing requires a face mount anyway. Doesn't it?

No need for the toothed flange for feedback. The standard industrial thing is an "encoder" mounted to the shaft at the other end of the motor.

I'm hoping we can couple the motor to the SOGOS with an off-the-shelf precision rigid coupling.

Either a keyed clamp coupling
http://www.ruland.com/ps_couplings_rigid_mspc.asp

or a shrink-disc coupling
http://www.conbear.com/MAV%20Standard%20Series.pdf

The first would require the SOGOS to have a keyway machined into it, and a key fitted.

The shrink-disk coupling looks a bit like a plumbing compression fitting and can't use a key, so you'd have to put a half key in the existing motor-shaft keyway.

They are both available with some stepped diameters, provided both motor shaft and SOGOS are standard sizes.

Has anyone else used either of these, or can point us to other EV conversions that used the gearbox tail for direct drive, or have any thoughts on the matter?
Last edited by weber on Tue, 17 Feb 2009, 11:19, edited 1 time in total.

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Direct Drive: Mechanical issues

Post by fuzzy-hair-man » Tue, 17 Feb 2009, 22:18

So a photo of Zeva's gearbox

Image

Where I mean is there's a join in the gearbox between where the jack is on the left and the brass gearbox drain plug, if you used the housing to the rear of that and mounted a aluminium plate on the front to which mounted to your motor, it might even be possible to use the original speedo drive! although the little plastic cogs probably wouldn't last long unless there was oil running around in there. Image

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Post by Johny » Tue, 17 Feb 2009, 22:23

No, you got the point and ended up at about the same place we are at.
So the big question is can the front bearing of the motor take oil up against it and not flush out all the grease.

The back end of the gearbox was what weber was calling the tail casing and I have called the tail-shaft housing. This is the bit you really have to partly fill with oil. Normally the gearbox oil flows into it at a height just level with the bottom of the rear tail casing seal.

I'll have to look on my car workshop manual tonight and see what they call it. At least we have agreed on the propshaft name...

There is also something deep inside of me that doesn't want ANY oil in my EV.

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Post by Johny » Tue, 17 Feb 2009, 22:30

Someone on DIYElectricCar used a shrink fit coupling and they destroyed themselves but this is no doubt manufacturer and implementation dependent.
I.E. How well were they made and rated and how well were they installed.

(I had to go back to my own post to remind myself what SOGOS meant.)

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Post by fuzzy-hair-man » Tue, 17 Feb 2009, 22:31

weber wrote: But using the gearbox tail casing requires a face mount anyway. Doesn't it?
Yeah, I just hoped (depending on whether you needed to keep oil in there or not) that it might have been considerably simpler (like a flat piece of thick aluminium) which the gearbox tail bolts up to (the holes are there already) it would get more complicated if you needed to keep oil in there though because you'd need an oil seal and bearing? in the face...

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Direct Drive: Mechanical issues

Post by fuzzy-hair-man » Tue, 17 Feb 2009, 22:37

weber wrote:
Has anyone else used either of these, or can point us to other EV conversions that used the gearbox tail for direct drive, or have any thoughts on the matter?
This is as close as I can get to using the gearbox tail for direct drive:
Image

from Birkin S3 kit Electric car

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Post by Johny » Tue, 17 Feb 2009, 22:59

OK. They did an intermediate shaft with a pre-packed grease bearing at the rear end of the tail casing. Since the tail casing isn't filled with oil it doesn't need the rear oil seal. So the answer here is to replace the rear bush (which is what mine has) with a grease fill bearing. The only thing is that the back of the tail casing doesn't look like it's big enough for the bearing they show.

http://www.electric7.com/construction.html

It leaves the speedo drive unlubricated but that's not an issue (for me).

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Post by weber » Tue, 17 Feb 2009, 23:14

fuzzy-hair-man wrote: I'm trying to stay with this discussion but having a bit of trouble...

So there's a bearing near the slip yoke at the rear of the ICE gearbox this is usually fed oil from the gearbox and is not usually a sealed bearing hence it needs oil.

You can't mount the shaft from the original gearbox (including the yoke) direct to the motor shaft and therefore have no need for the bearing at the rear of the gearbox? Isn't this what Mal's electrolux does?
Presumably you're worried it might stress the motors bearings too much causing failure? The motor bolted directly to the diff works because there's no propshaft stressing the bearings?

So if you were to do the SOGOS thing and replace the bearing with a sealed bearing? Ian's uses a sealed bearing right? I take it this what Johnny meant by "checking if sealed bearings are OK"

My other though was depending on the gearbox construction (sandwitch plate? I have the picture of a 1200 gearbox in my head) it might be possible to take the rear section of the gearbox housing off and replace the bearing with a sealed bearing then use the rear section of the gearbox to mount up to the motor. It might make a neat solution similar to Ian's open cage, if you were really lucky there might even be a mount on that part of the gearbox meaning one less engine mount you'd need to fabricate.Image

If you couldn't replace the bearing with a seal one perhaps you could seal up the rear section of the gearbox with another bearing and oil seal and fill the rear section of the gearbox with oil.

BTW Sorry if I entirely missed the point Image


Hi fuzzy-hair-man,

What you've added is the idea of replacing the existing plain bearing with a sealed ball bearing. (By a "plain bearing" we mean just hard surfaces sliding with oil between, no rollers or balls.) That is possible in the MX-5 because of the PPF, a rigid beam joining the diff housing to the gearbox tailshaft housing. In some rear wheel drives the propshaft must be free to slide axially relative to the gearbox as you go over bumps, hence the plain bearing. And yes, we'd like to use the existing speedo takeoff.

Thanks for that photo. It shows the MX-5 with the PPF removed, hence the need for a jack to hold up the back of the gearbox. Yes separating it at that joint is exactly what we had in mind. The speedo cable is exactly hiding the place where the lower flange of the PPF bolts to the gearbox tail, thereby holding up the front of the diff as well as the back of the engine/gearbox combination.

I know what you mean Johny, about not wanting _any_ oil. But there's gonna be some in the diff anyway.
Last edited by weber on Tue, 17 Feb 2009, 12:17, edited 1 time in total.

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Post by Johny » Tue, 17 Feb 2009, 23:36

weber wrote:I know what you mean Johny, about not wanting _any_ oil. But there's gonna be some in the diff anyway.
Damn!

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Post by Johny » Tue, 17 Feb 2009, 23:41

weber wrote:In some rear wheel drives the propshaft must be free to slide axially relative to the gearbox as you go over bumps, hence the plain bearing.
That's mine. The rear tail casing bearing is oil flooded and there is an oil seal to the rear of that. The slip-yoke has a polished outer surface that doesn't wreck the oil seal but can slide back and forth on the spline as the back axle jumps up and down and the hypotenuse changes.

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Post by weber » Tue, 17 Feb 2009, 23:55

Johny wrote: OK. They did an intermediate shaft with a pre-packed grease bearing at the rear end of the tail casing. Since the tail casing isn't filled with oil it doesn't need the rear oil seal. So the answer here is to replace the rear bush (which is what mine has) with a grease fill bearing. The only thing is that the back of the tail casing doesn't look like it's big enough for the bearing they show.

I think you've got that intermediate shaft back-to-front. The motor has a recessed female spline, and I'd say the bearing on the intermediate shaft fits inside the adaptor plate near the motor. I'd say they have kept the original plain-bearing/bush for the propshaft and I'd say there's oil in there.
Johny wrote: Someone on DIYElectricCar used a shrink fit coupling and they destroyed themselves but this is no doubt manufacturer and implementation dependent.
I.E. How well were they made and rated and how well were they installed.

(I had to go back to my own post to remind myself what SOGOS meant.)


Good acronym. I'll repeat it here for other readers: SOGOS = Sawn Off Gearbox Output Shaft.

There's a basic rule that you don't put more than 3 bearings on the same shaft and a rigid coupling makes it the same shaft. If you need to support it a third time or more, then you have to have a non-rigid coupling, such as a spline. Could that be why the DIYElectricCar one destroyed something. In our case, the motor shaft has two bearings and we are extending it rigidly but we are not supporting it again. Its male spline is free to float inside the female spline of the propshaft. It is the propshaft that has the next bearing/bush.

Mind you, the misalignment allowed by that spline is very small so the rigid coupling will still have to be very accurate, and if the motor, with this shaft extension, is not dynamically balanced, then it will wreck the motor bearings. Maybe that was the problem?
Last edited by weber on Tue, 17 Feb 2009, 12:59, edited 1 time in total.

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Post by fuzzy-hair-man » Tue, 17 Feb 2009, 23:56

Johny wrote:
weber wrote:In some rear wheel drives the propshaft must be free to slide axially relative to the gearbox as you go over bumps, hence the plain bearing.
That's mine. The rear tail casing bearing is oil flooded and there is an oil seal to the rear of that. The slip-yoke has a polished outer surface that doesn't wreck the oil seal but can slide back and forth on the spline as the back axle jumps up and down and the hypotenuse changes.
Thanks that explains it I was trying to remember from a while back, then got confused because I for some reason thought the MX5 had beam axle suspension and was wondering how the diff and gearbox were rigidly attached to each other. Image

I also didn't read the description of Mal's drive-shaft correctly Image

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Post by EV2Go » Wed, 18 Feb 2009, 00:34

A little hard to follow with a few wrong terms being used but I think I have worked out what is going on...

Firstly the correct terms for the bits in question starting at the back working forward.

The bit on the end of the tail shaft / prop shaft (if you like the Eng / US term) is a yoke or slip yoke
The alloy housing bit that yoke slips into is called a gearbox extension housing
The shaft that protrudes from the gearbox extension housing which the yoke slips onto is called the gearbox output shaft
The bush (not bearing) that sits inside the gearbox extension housing is called a output shaft bush (and seal)
The bearing located roughly where the gearbox extension housing bolts on is called the rear gearbox bearing and the one in the middle is the intermediate gearbox bearing

Ok from what I can see of the pics you are trying to emulate the same thing the TransWarp motors which uses the short GM TH400 gearbox extension housing, bush and yoke, but you want to do it with a different gearbox extension housing.

I wonder if on the TransWarp motor they replaced the rear bush with a sealed bearing... I digress

Firstly you will need to keep oil in that rear section for two reasons. The first being the yoke will chew out or fuse onto output shaft bush in no time without lubrication and two the speedo gears will definitely chew out in no time flat without oil.

I think what you are prosing is doable but there are a couple of things you need to consider... the TransWarp has a beefed up rear bearing to cope with the loads of the slip yoke. Using the rear half of the box might not be the easiest way to do the middle section... instead I would leave the rear section as is up to the rear gearbox bearing (so keep yoke, bush, rear seal, gearbox extension housing and a good portion of the gearbox output shaft) and fabricate the part in the middle.

It would far easier to get that section right if you build from scratch, if you use the factory housing you face having the intermediate bearing (front in this case) up against the motor bearing plate, but if you build the centre out of some sturdy alloy you could sit that bearing further back and allow for the drain idea that was discussed earlier. Also this would make it easier to couple the motor output shaft to the gearbox output shaft (which would become an input shaft).

If someone can tell me how to post a pic I could probably knock up a paint version of what I am talking about.

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Post by weber » Wed, 18 Feb 2009, 02:53

Johny wrote: That's mine. The rear tail casing bearing is oil flooded and there is an oil seal to the rear of that. The slip-yoke has a polished outer surface that doesn't wreck the oil seal but can slide back and forth on the spline as the back axle jumps up and down and the hypotenuse changes.
The MX-5 is constructed exactly the same at the gearbox end, with the slip-yoke able to slide in and out, although it barely needs to, except due to flexing of the the PPF (Power Plant Frame: the alloy truss beam connecting gearbox housing to diff housing). The diff is mounted to the underside of the rear subframe and the drive-axles have CV joints at the diff and wheels. I understand that in your case the diff moves with the wheels.

But if we solve your problem, we also solve Coulomb's and mine.

Here's a better version of the extra-oil-seal-and-drain-at-the-motor idea: The adapter plate is made thick enough that you can drill a long drain-hole vertically through it. i.e. the big hole in its centre is made to take a standard oil seal and the cavity left between oil-seal and motor is drained by a hole drilled vertically through the adapter plate. There could be another hole at the top to let air in. Alternatively a vertical groove could be milled in the adapter plate, on the side that goes against the motor flange.

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Post by weber » Wed, 18 Feb 2009, 04:33

Thanks EV2Go,

You have understood the situation. But we can't replace the rear bush with a sealed bearing because:
(a) there doesn't seem room for anything other than a bush, except maybe a needle roller bearing, and
(b) then the slip yoke couldn't slip axially. Or at least, if it could still slip axially, it would still need oil from the inside.

I agree we have to keep oil in there.

I don't understand why the motor bearing would need beefing up, as the bush, not the output-shaft, should take the weight of the slip yoke.

The idea is to cut the gearbox output shaft to the right length, somewhere between the rear gearbox bearing and the speedo gear, and couple it to the motor shaft.

Why do we need an intermediate bearing at all? Why can't we use a precision rigid coupling to make the SOGOS (sawn off gearbox output shaft) into a balanced extension of the motor shaft? So the two existing motor bearings take the place of the two bearings that supported the output shaft in the gearbox.

To post a pic, when you reply (or quote) there is an Insert Image button and an Upload Image button (with pictures of trees in them) at the top of the edit field. Love to see your sketch.

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Post by Johny » Wed, 18 Feb 2009, 04:53

I would have thought that a standard ACIM can handle the axial load of the weight of half a prop shaft. That is the way a4x4kiwi did it and it's my fallback if the extension housing idea gets too difficult.

Back to using an extension housing.
If I don't use a face mount motor, how about making up a rear plate with oil seal for the extension housing and mounting it on the same mounting bars as the foot mount motor but with a gap to accommodate the coupling between them.
Basically a strong L shaped plate (looking from the side). The vertical part is the rear plate and the horizontal part is the mounting for the motor - maybe reinforced.

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Post by weber » Wed, 18 Feb 2009, 05:45

Johny,

If you did that, you'd definitely have to have a bearing in that plate, supporting the SOGOS, and a flexible coupling such as a gear coupling
http://www.daltonbearing.com/viewproduc ... idadd=1084
between the motor shaft and the SOGOS, to allow for the inevitable movement between the motor and the gearbox tail housing.

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Direct Drive: Mechanical issues

Post by mjcrow » Wed, 18 Feb 2009, 05:57

Johny wrote:
weber wrote:I know what you mean Johny, about not wanting _any_ oil. But there's gonna be some in the diff anyway.
Damn!


Who needs oil? Link

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Post by Johny » Wed, 18 Feb 2009, 16:07

Yes, I realised that I had described a fairly normal way of coupling a motor to a driven device on the same plane once I had posted. Given all the problems I have read about to do with motor and coupling misalignment destroying motor bearings - probably best to avoid.

EV2Go. You said "The first being the yoke will chew out or fuse onto output shaft bush in no time...". How does a4x4kiwi's external slip yoke get lubricated? Is it just a greased spline?

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Post by EV2Go » Wed, 18 Feb 2009, 17:03

Hi Weber, sorry you must have miss understood I wasn’t proposing replacing the rear bush with a bearing of sorts, as you rightly point out there is extremely limited space back there, as it was designed with a bush in mind. Some housings may have sufficient material to machine out and fit a needle roller bearing but it wouldn’t bother.

The purpose of the bush is not to provide a bearing surface, but rather to stop the yoke from getting too much sideways movement on the output shaft. Think of it this way... remember the bad old days when cars had leaf springs in the rear suspension, when you hit a pot hole or went over a sharp bump the diff would go up or down altering the tail shaft angle and rotate the diff itself slightly, and if the car dropped or rose on one side only it would also cause a slight twist. It was back in these days that a slip yoke really needed to slip backwards and forwards.

If you think of the tail shaft as being a straight line, any movement at the diff would alter the angle of the front uni of the front slip yoke, while the uni will absorb a great deal of that twist, some of it is transmitted via the slip yoke to the output shaft. The purpose of the bush was not to provide a bearing surface but rather limit the amount of slip yoke sideways movement on the output shaft. The slip yoke doesn’t even touch the bush there is a thin film of oil that sits between them, without that oil present the because the bush is static it will chew out very quickly.

Many of the modern cars with independent rear suspension have the diff firmly mounted to the chassis reducing that flex enormously. The use of a centre joint (basically gives you two tail shafts) to reduce vibration reduces that vibration load on the output shaft even further. So you really shouldn’t consider that bush as load bearing. I will try and put together a picture of what I had in mind when I get a chance.

The TransWarp uses a beefed up end plate bearing to help cope with this load, as the motor bearing is the last point that supports the output shaft of the motor. If you have another beefy bearing parallel to the motor end plate bearing, it can carry the load on behalf of the end plate motor bearing, but it needs to be far enough back from the motor bearing to be of benefit.

Johny: I took a look at a picture of the TransWarp last night and it has grease nipples on it, so it looks like the TH400 Netgain sell is a modified version of the factory one which only has a bush and relies on oil.
Last edited by EV2Go on Wed, 18 Feb 2009, 06:13, edited 1 time in total.

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EV2Go
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Direct Drive: Mechanical issues

Post by EV2Go » Wed, 18 Feb 2009, 17:49

Ok it is a bit rough as paint gernerally is...

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Johny
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Direct Drive: Mechanical issues

Post by Johny » Wed, 18 Feb 2009, 18:10

Looks good.
So if I assume motor to gearbox output shaft uses a splined to key-way coupling. Spline on gearbox output side, key-way on motor side.

Does this sound right - you would assemble it as follows.

1/ Attach the coupling to the motor
2/ Attach the red housing to the motor
3/ Slide the gearbox output shaft into the splined coupling and bolt the yellow section to the gearbox extension housing.

The red section could be open as per one of my previous posts. Maybe a 4 or 5 sided box (top and bottom or just top missing - or removable). That way it would be easy to get at the coupling if you decided to use shortened gearbox output shaft with no spline.

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