Oil cooling your hub- NOT snake oil!

[Merlin]

Yes, I am currently using the motocross valves. They work, but you still have to stop once (after you've heated the oil) to release the pressure. I'm just looking for the ideal solution. This is better, but not the best. I tried the pinhole method at first. It worked ok. I would get about a drop per ride coming out the cover. Not even enough to get on the brake disc. Still had to do a wipe down every couple rides though. I'm looking for a small, automatic release valve. No luck so far.

Also, I'm currently running 650ml of oil (takes a very long time to heat up the motor, and the peak temp is MUCH less). This is exactly half the open volume of my 9c motor, so the oil comes right up the the axle. I've had it squeeze out of the wires. You can actually watch it happen if you stop the bike, and wait a minute for the oil to seep. Once the motor begins to cool, it sucks back inside the axle. I thought I did a pretty good job of sealing within the motor where the wires enter the axle. Guess not. Still trying though!

whats about Gore TEX valves?

 

[izeman]

yes. this was something already thought about. but i don't know if someone tried before.
i don't think there needs to go too much effort in designing the breather. as long as there is little oil in the motor, and the breather is installed in a clever position (like on your picture) it should be working good.
i personally like the idea of a 1cm long plastic tube being flat on the ouside and reaching into the motor a bit. this way only air should be able to go in/out.

 

[Merlin]

think so too, the gore valve i cannot find to buy
the M12 hole will be better to fill the motor but i think a needle will work too.

in the next one or two weeks i want to give it a try. For that try i will dismount my rear brake cos i dont want to buy new brakingpads when oil comes out.
it will suck to refill for test but i want the hole on cassette side.
i will start at 100ml. I have a mountain behind my house (5km uphill)
i will do test with watt limit (4kw) and speed limit(20kph). i think thats the best idea to compare these tests.
after every corner full throttle till next corner.filmed with gopro and GPS logger.
every start with 40° Motor temps. so i dont have to wait till motor has ambient temperature on same day (after hillclimbing) maybe i cool down with water...

I hope i seal the motor right.....iam not that type of beta tester who has fun open a motor everyday ;(

 

[The Stig]

in the next one or two weeks i want to give it a try. For that try i will dismount my rear brake cos i dont want to buy new brakingpads when oil comes out.
it will suck to refill for test but i want the hole on cassette side.
i will start at 100ml. I have a mountain behind my house (5km uphill)
i will do test with watt limit (4kw) and speed limit(20kph). i think thats the best idea to compare these tests.
after every corner full throttle till next corner.filmed with gopro and GPS logger.
every start with 40° Motor temps. so i dont have to wait till motor has ambient temperature on same day (after hillclimbing) maybe i cool down with water...

I hope i seal the motor right.....iam not that type of beta tester who has fun open a motor everyday ;(

What motor are you doing this with? synthetic ATF oil I assume...
According to Marc S it may not be necessary to seal the motor if you don't put to much oil. In which case a breather may not be necassary either because the motor can breath through the wire hole in the axle and the bearings.

Has anyone had leakage through the bearings or are they generally well sealed? Has anyone replaced them with better sealed bearings?

One of these days I'm going to try adding oil to my Ezee motor the way it is. Its has been running at 1.3-1.5kw for a while and the freewheel has gotten stuck. I could up the power more but the lyen Infineon mk1 controller makes the bike kick really hard when I turn the throttle slightly.

Haha! this was my 666th post

 

[itchynackers]

The motor definitely breathes through the wires. I tore down my motor over the winter. Previously, I had no leakage through the original bearings or covers. I put in Japanese bearings and when I pressed them in, I put a skim coating of high temp silicone on the outer bearing surface, and on the surface that the bearing fits into (just to be safe). I also put a thin coat of silicone on the covers. I also globbed silicone around the inside of the motor where the wires feed into the axle. I still don't get any leakage except through the wires. I have a pressure relieve valve (manually operated), however I'm too lazy these days to use it. I just let it come out the axle. Keep in mind, that I've been running 650ml (motor half full), so the fluid is right up to the axle. You may not get any leakage if you use less oil. Ultimately, I'd like a passive pressure relief valve (maybe 0.5psi), but I haven't been been able to find one.

 

[The Stig]

Well I guess it comes down to getting the right amount of oil - how much is needed for adequate cooling... (for a MAC... I guess you wouldn't want too much anyway because it would create drag in the gears)

I have a new idea for a breather: A small tube just stuck slightly into the wire tunnel in the axle on the inside. Then the other end of the tube should be somewhere higher up on the stator pointing downwards. Then silicone and seal the axle's wire tunnel on the inside.

 

[spinningmagnets]

I had a thought today, what about using a standard Schrader valve (bicycle tube air-fill stem) as a check valve? Drill a hole and and tap threads into the sideplate near the axle. Use Locktite fluid to prevent loosening, insert a cut off stem. heated air can escape, but when cooling, a partial vacuum forms inside the hub.

Only concern I can think of is difference of internal/external air pressure would pull off internal silicone on the joints?

The standard Schrader valve has the following threads:
External thread
• Metric: 7.7 mm OD, thread root diameter is 6.9 mm × 0.794 mm pitch.
• Imperial: 0.305 in OD, thread root diameter 0.271 in × 32 tpi (threads per inch)

 

[The Stig]

Hows the heat resistance of the plastic and rubber parts in a valve stem?

 

[spinningmagnets]

The metal shell that is threaded is typically brass (I expect the internal coil-spring to be steel, while the valve parts might also be brass). I expect the rim of the motor shell to become the hottest part due to centripetal spinning action of the hot oil. Near the axle shouldn't be very hot, although I suspect all the rubber parts of a tube valve stem can be cut off.

The hole diameter that would be required in the side-plate should be small, so it wouldn't be a disastrous experiment, and the future substitution of an alternative vent would still be possible.

 

[teklektik]

I had a thought today, what about using a ... check valve? ... heated air can escape, but when cooling, a partial vacuum forms inside the hub.

As Justin mentioned, the reduced pressure on cooling is a primary cause of water ingress. Corrosion is probably less of a concern with the oil bath, but it seems the solution should preferentially incorporate a vent, not a one-way valve.

 

[spinningmagnets]

The benefit of Gore-Tex in clothing is that humidity from sweating and exertion can pass through, but liquid (like rain) cannot get in. So, water vapor can be pulled into a hub with a Gore-Tex valve, then condense into liquid after cooling off inside the hub. The Gore-Tex would keep dirt and water from getting in, and it would keep the internal and external pressures equal. Of course the oil would be kept inside.

One thing I learned when studying automatic transmissions in cars; it is possible to cool the oil too much. Condensed humidity will turn the oil milky, and the solution is to add a thermostatically-controlled bypass valve to allow the oil to get hot enough to "boil off" the moisture by maintaining the design temps above 180F / 82C. Allowing the hub to regularly get up to 140F / 60C should rid the interior of any moisture.

Gore-Tex website snap-in vent specs:
http://www.gore.com/en_xx/products/venting/protective/products/snap-in_holder.html

A seller in Australia:
http://www.shapers.com.au/categories/Vents-&-Air-Breathers/Gore%2dTex-Breather-Values/

 

[teklektik]

The benefit of Gore-Tex in clothing is that humidity from sweating and exertion can pass through, but liquid (like rain) cannot get in. So, water vapor can be pulled into a hub with a Gore-Tex valve, then condense into liquid after cooling off inside the hub. The Gore-Tex would keep dirt and water from getting in, and it would keep the internal and external pressures equal. Of course the oil would be kept inside.

Possible issues with GoreVents in Justin's thread: Definitive Tests on the Heating and Cooling of Hub Motor

• 
  http://endless-sphere.com/forums/viewtopic.php?f=2&t=48753&p=744316#p744104
  http://endless-sphere.com/forums/viewtopic.php?f=2&t=48753&p=744316#p744201

No point in speculating on this here - just await evaluation results from Justin & Robbie in the other thread....

 

[Sancho's Horse]

I have been puzzling over this for awhile. Clearly the answer is reusable pop up turkey thermometers...185 Fahrenheit or 85 Celsius...metal melts...pop! pressure release.

Just kidding...somewhat.

I have found centrifugal valves, valves of various materials, lots of programmable temperature release valves, but aaah, just cannot find the one. Cost, size, complexity. But I feel like I am at least in the right part of the industrial complex, and maybe getting closer/talking to the right people. The natural gas industry has lots of temperature release valves, but for those guys money is not much of an object. Just finding the right size/cost is the trick.

 

[The Stig]

Yeah something like that would be good. Something that will block water and still take the heat

 

[Sancho's Horse]

Yeah they are exactly what is needed performance wise, except for the price (and maybe the dimensions...although with a little creativity...a fine size). The AMOT 2230/4430 2-way valve may be the cheapest...not sure...but the cheapest I have found it for is $39 on ebay (although I have not contacted a dealer).
http://www.amot.com/products/pneuma...260/22304430-2-way-temperature-sensing-valves
Essentially a stainless steel enclosed wax, which when heated expands and moves a valve at the factory set-temp...it begins bleeding pressure at 1-2 degrees from the set-temp. It cannot take sustained operation above 129C, but below that it is fine. They have others which you can set the temp on yourself, and have a much wider range of operating temps, but I am guessing they are more expensive and involved operationally.

 

[Martin A]

To prevent the problems associated with hub pressurisation due to temperature rise why not have a vent into a sealed balloon or plastic bag inside a vented protective canister. It inflates as the temperature and pressure rise and then returns to normal as the temperature and pressure drops. Someone could do the maths but I'd be surprised if the increase in volume due to temperature would require much of an expansion bag. A syringe could also be used but then there's the problem of stiction of the seal.

This way the hub remains sealed negating any worries about moisture ingress or loss of coolant.

 

[speedmd]

Found some Mini check valves that may work.http://www.industrial-microhydraulics.co.uk/check_valves.htm

 

[The Stig]

yeah I like the expansion bag idea, but not sure what parts to use.
I have some pipe from an auto parts store that I could silicone into both ends of the wire channel(in the motor axle). So on the inside of the motor I would just mount the breather tube opening facing downwards and on the outside I would mount an expansion bag to.


A small oiled filter might work like this one that is used by 4x4 drivers for their transmission breathers etc.

You can also find them in your local automotive store too.

I found a nice small air breather from AutoZone, $9.95 It’s made by “Spectre” Part number 3992, they come in different colors, Silver, Blue, Red, Yellow,etc. The following are pictures of the small colored Filters, they are very similar to a K&N filter. I used a little oil on mine to keep it water proof too.

I went ahead and did the leg work for everyone for the small colored breathers.

Here is the following part numbers for the colored filters

Specter Part number # 3992 Red Breather

Specter Part number # 3994 Yellow Breather

Specter Part number # 3995 Silver Breather

Specter Part number # 3996 Blue Breather

Specter Part number # 3998 White Breather

 

[sabongi]

Have you tried using transfomer oil?

 

[Martin A]

yeah I like the expansion bag idea, but not sure what parts to use.
I have some pipe from an auto parts store that I could silicone into both ends of the wire channel(in the motor axle). So on the inside of the motor I would just mount the breather tube opening facing downwards and on the outside I would mount an expansion bag to.


A small oiled filter might work like this one that is used by 4x4 drivers for their transmission breathers etc.

You can also find them in your local automotive store too.

I found a nice small air breather from AutoZone, $9.95 It’s made by “Spectre” Part number 3992, they come in different colors, Silver, Blue, Red, Yellow,etc. The following are pictures of the small colored Filters, they are very similar to a K&N filter. I used a little oil on mine to keep it water proof too.

I went ahead and did the leg work for everyone for the small colored breathers.

Here is the following part numbers for the colored filters

Specter Part number # 3992 Red Breather

Specter Part number # 3994 Yellow Breather

Specter Part number # 3995 Silver Breather

Specter Part number # 3996 Blue Breather

Specter Part number # 3998 White Breather

Put a balloon inside this filter. It looks ideal and hi tech too

 

[The Stig]

Thats actually a pretty small filter, I don't think there is enough room in that filter for a bag to expand. You would want a bag rather than a baloon because you wouldn't want any pressure to build up in the motor, negative or positive.

I'm not sure what kind of oil I would put on this filter to make it water resistant...

Heres a pic of the filter under the hood of an FJ cruiser:

 

[The Stig]

The axle in my Ezee motor keeps leaking oil. I didn't put silicone in it before adding oil because it was already installed on the bike.

Would it make a big difference to flip the Axle 180? The opening in the axle is on the flat side so as it sits in my dropouts, it faces slightly upwards, if I were to twist it 180 it would face slightly downwards, so maybe the opening on the inside wouldn't catch as much oil...

Does anyone know of any sealant that would do the job of silicone, but work on an oily surface?

 

[-dg]

The axle in my Ezee motor keeps leaking oil.

How much oil did you put in?

 

[The Stig]

About 60ml. But it still drips even when most of it has dripped out

 

[GCinDC]

The axle in my Ezee motor keeps leaking oil.

which motor? which side? so it's either leaking through the inside of the bearing or around the bearing or the wire slot/wire hole if it's wire side...

Would it make a big difference to flip the Axle 180? The opening in the axle is [what opening is that? where wires come out?] on the flat side so as it sits in my dropouts, it faces slightly upwards, if I were to twist it 180 it would face slightly downwards, so maybe the opening on the inside wouldn't catch as much oil...

sure, try flipping it. if it's not properly sealed tho, it's gonna leak. i used a generous amount of sealant under the bearing, over the bearing, in a giant mount around the wires before they exited, but i used a clear sealant, not ATF. it lasted for several weeks and eventually leaked through the bearing. i'm considering doing it again with permatex this time so we'll see.

Does anyone know of any sealant that would do the job of silicone, but work on an oily surface?

omg, i doubt it. however, if you spray some of this on the area to seal:

you'll be able to have the sealant adhere like it were dry, cause it will be dry.

good luck.