Milling noise FIX

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asavage said:
I have been told that the Tony's FB group is private. Not a company communication channel, then.
Private groups in Facebook just require a request to join the group. There are usually simple questions so that the group admins and moderators can weed out the spammers and fake users. The information inside the group can only be viewed by members of the group, it usually cannot be seen by non-members and scraping bots. However, as you indicate, it's no substitute for a business web site.
 
Thx for the explanation of how FB Private groups (forums) work.

I've run a phpbb website since 2006. That's forum software, the same as this site actually, though mine is several security versions newer than myrav4ev.com . It has an option for private forums, and I do have one that's just for myself and a couple of friends, for very non-public information sharing about house renovations etc. Nothing nefarious, just stuff I would otherwise use something like Dropbox for.

However, because it's private it is useless for either communication with public or knowledge sharing beyond the circle. I've got thousands of posts and pictures that are publicly searchable and useful to anyone looking for an answer to their question. I welcome 'bots scraping my content, because the forums I run are not a profit center for me. People can get at what they want without becoming data for a corporation whose sole purpose is to sell data about you.

Whatever is posted behind FB's private forums is useless to the wider world unless someone joins their club . . . and becomes data for FB to package and sell.

Sorry, OP, for vectoring so far off topic.
 
Schenkzoola said:
Only one mechanical seal is required to seal the rotating motor shaft. Unfortunately for me, this seal had failed, and I could not find a direct replacement. The seal dimensions are 30x55x8mm. It is a double-lip teflon seal with an excluder. If you happen to know where I could get these, please let me know!

Due to the high surface speed, I do believe that a Teflon seal is the correct choice here. I did my best to find something suitable that I could buy off the shelf.

Without hits: I looked at Garlock, Chicago Rawhide (SKF), and Parker so far. It looks like Parker might have used to have that seal, but as of Dec2020 they've dropped the PTFE product in the FlexiCase (metal case) configuration.

So far, only this Chenming seal:

(wait for it to load)
Tesla_Rotor_Coolant_Seal_30x55x8mm_01b.png


It's dual-lip (in single direction) with excluder (in other direction). But I'm much more comfortable with seal manufacturers whose products I've used or at least heard of before.

Folks who are repairing these are keeping the info close, I suppose.

[later]
Lemming Co./elastoring.eu 48001848, but has no lip configuration info.
Tesla_Rotor_Coolant_Seal_30x55x7mm_02b.png
 
asavage said:
... Folks who are repairing these are keeping the info close, I suppose.
and / or buy there and then resell (IMO).
Note. The Rotor requires 2 teflon seals: 36*67*8 and 30*55*8.

For reference.
https://docs.google.com/document/d/1A6n0bkLowViFNtoD2bjzkL_IHk5RLS-mvYRUpe2qzGA/edit
https://photos.google.com/share/AF1QipNb3tKJYPQpYjbX5qyQYV5crZspYhDeIPlRPkL53tDdflzRYxezu_ypSV4JfflioQ
 
Your last link is a 404.

Nathan/Schenkzoola's pictures do not, unfortunately, show the 36*67*8 seal on the gearbox end of the rotor (though I can just make out the brushes).



He does not mention replacing the seal on that end. Presumably, its function is to keep ATF from the gearbox from infiltrating the brushes and stator cavity.

I haven't seen pictures of that larger seal, nor of the brushes better than those.

He's replaced the original rotor bearings SKF BB1-3793 (assumed ceramic balls) with similar spec 6007-2RZTN9/HC5C3WT (definitely ceramic balls).



Alex UA says he replaced the gearbox pinion (gearbox input) bearings with ceramic ball bearings as well, but to me that implies that if the rotor shaft brushes are not doing their job, and induced current cannot be diverted to case ground via the brushes, and both the two rotor bearings and the gearbox input bearings are electrically isolated by ceramic balls, then the gear input pinion gear teeth become the next least-resistance conductor. I think I'd rather sacrifice the ball bearings.
 
asavage said:
.... I think I'd rather sacrifice the ball bearings.
Where are the brushes in this motor? Please, show their photos?.
3ph_motor_rot_field_an.gif
,
https://youtu.be/AQqyGNOP_3o

Just checked both links and they work.
 
Tiny circumferential brushes are shown in the first picture, my previous post. They surround the shaft. Click on the picture (it’s a link to a larger version) and zoom in. It’s not a great pic, but it’s what I have.

The brushes are not there for motive power transfer.

Your second link is still a 404 here. Both on my phone, and my home network.
 
asavage said:
Tiny circumferential brushes are shown in the first picture, my previous post. They surround the shaft. Click on the picture (it’s a link to a larger version) and zoom in. It’s not a great pic, but it’s what I have.
The brushes are not there for motive power transfer.
Your second link is still a 404 here. Both on my phone, and my home network.
Apparently, after the translation, we have a different understanding of the term "brushes" :(
I understand this
hqdefault.jpg


Try https://photos.google.com/share/AF1QipNb3tKJYPQpYjbX5qyQYV5crZspYhDeIPlRPkL53tDdflzRYxezu_ypSV4JfflioQ?key=TGE5dTlidWtyMXJ4TzNHZEZfdGhoWm4xRzFkWmtB
 
That link works. It's a link to the same photos Nathan posted in the first post of this thread, though. And, that's where I borrowed the two pictures of the rotor drive end bearing and brushes above.

Jack Rickard of EVTV talks about a Helwig Carbon Products rep talking about induction motor bearing protection brushes for safely diverting stray induced rotor current to ground, and Jack mentions that the rep intimated that he consulted with Tesla on this practice.

The general idea looks like this, though the Tesla Model S LRU's brushes don't look anything like this:



Jack talks specifically about the LRU brushes here, but still only fuzzy pictures of the thing, not even as good as Nathan's above.

An interesting article about ceramic ball bearings and EVs: https://chargedevs.com/features/ev-motor-shaft-bearings-one-of-the-few-moving-parts/

----------------------------------------------------------------------

This discussion of bearing protection brushes brought to mind my experience with my '59 Cadillac Eldorado Seville, which I owned in 1980-81.

For many years, Cadillac installed a "radio static collector" spring in the front wheel bearing grease cap. At some point, this spring was discontinued, but I was sufficiently surprised by seeing one installed that the memory remains more than forty years later.

Cadillac_Radio_Static_Collector_01b.png

Cadillac_Radio_Static_Collector_02b.jpg


As shown in the exploded view above, Cadillacs through 1959 used ball bearings on the front wheel hubs. These had a short service life. For 1960, Cadillac finally updated to roller bearings. More friction but also more bearing contact area. After two ball bearing failures on mine, it was upgraded to a pair of junkyard-sourced 1961 DeVille front hubs :) Much improved durability. I sold the car in late 1981, I believe.
 
Thank for Clarification.
For devices that protect against electromagnetic waves, we use the term "ekran" ("shield")
https://en.wikipedia.org/wiki/Electromagnetic_shielding

Video to RAV4EV Ceramic Bearing
https://youtu.be/C8oxv7ILcHU
 
Electromagnetic shielding is placing a barrier between EMF or EMI, and the device to be protected. That is not what the drain brushes on the Tesla rotor are (supposed to be) doing.

If the SKF BB1-3793 rotor bearings have ceramic balls and nylon spacers, does anybody know why they are failing? Theoretically, these ceramic ball bearings should be more robust than the metal ball bearings typically used in lower-speed motor rotors. They can't be failing because of stray rotor current, if the bearings are nominally non-conductive.

Example Tesla Model S LRU rotor bearing wear noise.

Nathan said that the bearing with the most wear was the gearbox input pinion bearing, which is non-ceramic, but Jack Ricard's noisy bearing is the rotor idle end bearing, which should be ceramic (barring running revision changes; it's possible that Jack's example DU is an earlier version that might be pre-ceramic bearing).
 
asavage said:
Electromagnetic shielding is placing a barrier between EMF or EMI, and the device to be protected. That is not what the drain brushes on the Tesla rotor are (supposed to be) doing.

If the SKF BB1-3793 rotor bearings have ceramic balls and nylon spacers, does anybody know why they are failing? Theoretically, these ceramic ball bearings should be more robust than the metal ball bearings typically used in lower-speed motor rotors. They can't be failing because of stray rotor current, if the bearings are nominally non-conductive.

Example Tesla Model S LRU rotor bearing wear noise.

Nathan said that the bearing with the most wear was the gearbox input pinion bearing, which is non-ceramic, but Jack Ricard's noisy bearing is the rotor idle end bearing, which should be ceramic (barring running revision changes; it's possible that Jack's example DU is an earlier version that might be pre-ceramic bearing).
One possible reason for the noise of non-ceramic bearings under a microscope
https://youtu.be/VW4_ICHFTM0

Ceramic rotor bearings (usually / more often on the outside / right side of the motor) are noisy due to the ingress of coolant through the seal.

Update.
_2041s.jpg
 
I believe the recommendation is to replace the coolants at 50K miles. I wonder if replacing the coolants sooner would better protect the seals from leaking? Perhaps water content in the coolant is causing the seals to fail.

This issue seems to be 0ne 0f our biggest issue going forward. Would it be possible to modify the speed sensor with a sensor to catch this problem quickly before catastrophic damage? Also, who, other than Tesla, can replace the seals?

thanks
James
 
james said:
I believe the recommendation is to replace the coolants at 50K miles. I wonder if replacing the coolants sooner would better protect the seals from leaking? Perhaps water content in the coolant is causing the seals to fail.
This issue seems to be 0ne 0f our biggest issue going forward. Would it be possible to modify the speed sensor with a sensor to catch this problem quickly before catastrophic damage? Also, who, other than Tesla, can replace the seals?
thanks
James
I plan to install such a device in my RAV4EV for timely indication of coolant leakage into the engine
https://youtu.be/ps2gha4w5YE

In Ukraine, replacement with the installation of teflon (PTFE) seals* and ceramic bearings* (and others) is done in a dozen adequate services.
*
20210810_173508.jpg
 
alflash said:
asavage said:
.... I think I'd rather sacrifice the ball bearings.
Where are the brushes in this motor?
It took a few months, but there's my reply:



[Sep2022: BTW, not a nice trick, you taking my pictures above, editing them, and inserting them months later into your own post above. That changes the reading of this thread quite a bit.]

james said:
I believe the recommendation is to replace the coolants at 50K miles. I wonder if replacing the coolants sooner would better protect the seals from leaking? Perhaps water content in the coolant is causing the seals to fail.
Hazarding a guess, it's the speed of the rotor (the feet-per-minute spec of the seal). But, I am not a seal engineer by a long stretch, so this is only a guess.

Particulates (in particular, yuk yuk) plus that high rate of f/min could lead to unreasonable wear from an durability engineering perspective.

james said:
This issue seems to be one of our biggest issue going forward. Would it be possible to modify the speed sensor with a sensor to catch this problem quickly before catastrophic damage?
The speed sensor is located at nearly the highest place in the motor that could sense stray moisture, though of course that's where people check because it can be unbolted easily. Removing the speed sensor as a spot check is great, but I'd rather sense moisture at the low end, where gravity can assist, and which would yield an earlier warning. I rather like alflash's low location at the bottom of the motor case, just to one side of the internal lateral water passage from the rotor end housing to the inverter.



The OP's drain location in the rotor end housing:



That location would likely catch a leak in the seal quickly, but might miss a leak at the inverter end for quite a while. While I've not heard reports of an internal leak in other areas of the old Tesla DUs, there are a few more coolant joints (inverter heat sinks have some) and I'd like to install one sensor that covers everything.

A few months back, I was scouting for the perfect place to drill a ~10mm hole, in which to insert an adapter and tiny drain line (or just a probe adapter), to which I could attach a moisture probe (essentially, a pair of electrodes). Once that mechanical tap is in place, a variety of ways to trigger alarms, bells, whistles, indicators, or automated email alerts every time you open your phone, could be deployed.

Going in blind, I'd want two pieces of information: the location to drill, and the depth. Lacking that, I'd need a donor motor case and the rotor end casting to take measurements myself. Since I have neither, I put my own personal project on back burner status until some other projects around here get sorted. It's on my To-Do list. I suppose if nobody else posts the info, I should go scouting for a junk half-motor. I don't need any of the expensive bits (inverter, gearcase). I've got a couple bookmarked, but again it's too far down my list right now.

james said:
Also, who, other than Tesla, can replace the seals?

According to a "EV Repair Technician at QC Charge", QC Charge (QC Power on Twitter) in far SoCal does it. I no longer work with Tony/QCP -- I've fired him as an approved vendor after three strikes -- but they are an available resource.

Rich Rebuild's shop, Electrified Garage have not replied to my multiple emails on this topic, so I assume that they're also not seriously in business. If you don't communicate with your customers, you're not a business. Having a nice web page isn't being in business.

I'd like to know of other vendors in the continental US who are conversant with this process, as opposed to a general EV shop that has seen the pictures and thinks it looks easy. If I'm paying for someone to do the work, I'd prefer they broke other people's hardware first, to acquire the knowledge of how to not break mine. BTDT.

20210810_173508.jpg


I'd sure like to know how to buy that "Made in USA" Tesla-branded seal.
 
This well-known illustration of the place of drilling a hole has long been on the Internet
2021-09-06_023033.png


And for a liquid sensor, a hole less than 5 mm is enough.
Any "seals" have been made in China for a long time :(

https://www.skf.com/us/products/rolling-bearings/engineered-products/hybrid-bearings/productid-6007-2RZTN9%2FHC5C3WT
 
[I was updating my post above as you were typing your reply.]

The OP posted his PDF 06Mar2019, and he had his DU out and disassembled. While drilling in that location is easy with the DU removed, perhaps not so much when a working DU is still in-situ. And, that location is good for detecting a seal leak, but there are other places internal to the DU that may leak in future.

The rotor housing low point, just to one side of the lateral water passage that travels to the gearcase, looks to be a good low point for sensing, and can be drilled easily without having to, for example, remove the DU.



alflash said:
Any "seals" have been made in China for a long time :(

https://www.skf.com/us/products/rolling-bearings/engineered-products/hybrid-bearings/productid-6007-2RZTN9%2FHC5C3WT

That link is to the bearing, unrelated to seals.

The seal shown in your picture is marked, "Made in USA". Seals are still manufactured in the US. I'd like to know how to purchase that one specifically.
 
Over on YT (youtu.be/W9ql5mo-QBQ *), Tony says they have a "kit", and it seems to have two low sensor locations. I think checking the inverter side would be nice, but if any significant amount of leakage occurs (say, a teaspoon's worth), with the heat generated by the DU it'll steam up everywhere. Hmmm. Maybe I just talked myself into a speed sensor hygrometer probe after all . . .



I would not think that the covers would need to be removed to drill holes the width of the castings, but then again I don't have the castings in front of me, and they do.

* Damned bbCode add-ons . . . always (frequently, anyway) doing something unwanted, like interpreting a link to YT and "helpfully" providing a static preview of the opening video shot.
 
1. I showed a link where you can buy a non-fake ceramic bearing in the USA what can be useful to others. Since the theme name is "Milling noise FIX".
2. Chinese "masters of counterfeiting" are capable of many things. For example, and this
seal_u.jpg

But the main thing is that Teflon must be used in the oil seal, and not ordinary / familiar rubber.

3. I have seen Tony's way of checking for fluid leaks in an assembly motor
photo in https://www.facebook.com/photo/?fbid=10220396285927967&set=g.2444294535613184 or
file.php


4. I'm a supporter of installing an electronic device, with the placement of a buzzer and LED in the vehicle.
 
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