The key to this differential is the fact that a worm gear can turn a spur gear but the spur gear cannot turn the worm gear. So it acts like a mechanical diode.
@@erikkovacs3097 when the engine is off and the car is moving, rotation from the wheels is transferred to the defferential then to the disengaged transmission, if I'm correct then the differential has to break or the car stop moving
In many ways, a torsen is often referred to as a fancy open diff. A clutch based limited slip, which is the most common LSD, is capable of locking the left and right axles together. The Torsen LSD is often referred to as a "torque multiplier" because it uses the spur gears to multiply the amount of torque one wheel gets, when the other wheel starts slipping. You can see the torque multiplication effect in the video when one wheel spins faster because the other wheel is stopped. In certain conditions, the Torsen diff won't work when the spinning wheel has zero traction, because it can't multiply zero torque. Because of that, and other reasons such as driver preference, more traditional LSD setups are preferred in racing or off-road applications.
If you want to get technical, it is a limited slip. While it can't solve the zero traction problem, it does try to ensure that 100% of the power is being used between both wheels (barring things like friction in its own operation) while an open diff is always just 50/50 split regardless.
@@markbickford9092 very good video. Once he said “the worm gear can turn the spur gear but not the other way around” it twigged in my head. Very clever. In practice I think the slope of the teeth means that one gear isn’t 100% spur and the other 100% worm, but changing that slope influences the torque threshold.
@@YoRHaAttackerNo2 except that the Torsen diff is not just a torque splitter, it's a torque multiplier. Going back to the open diff, it's commonly said that it always have a 50/50 split. What that means is that if the spinning wheel only can handle 25 ft-lbs of torque before spinning, then the stationary wheel would receive 25 ft-lbs of torque. Now take the Torsen with the same example. If the diff is rated for 3x torque bias ratio, then the stationary wheel would receive 75 ft-lb of torque if the spinning wheel can only handle 25 ft-lbs. This would be a variable 25/75 torque split, depending on the situation. This variability is a major reason why Torsens aren't always used in racing or off-road applications. In comparison, a clutch LSD would be sending up to 100% of the input torque to a single wheel if needed, or a max of a 0/100 torque split.
Very important to mention that this is a torsen differential in my opinion. When someone thinks of a limited slip differential it is not typically this differential, it would most likely be a plated limit slip differential as this is the most common seen in cars today. Not many manufactures use torsen diffs, they see the most use in audi's though.
Torsen was the only limited slip offered in the miata from 94 to 2003, and it is a limited slip in every sense of the word. Seems you lack experience. You don't just get to redefine things as you see fit, amber turd.
I mean, clutch LSDs may be more common overall, but I don't know if any modern car has one of those- helical (like Torsen) and viscous LSDs seem to be the only ones in production vehicles. Yeah there's some things the author could mention, but it's also a heck of a rabbit hole, haha.
I replaced my worn out clutch style with Torsen, drives much better and will never need a rebuild. As far as traction, it performs smoother than my clutch style LSD. Defenetly a bit more expensive and you lose a little efficiency hence the factory not putting them in many vehicles.
This is also referred to as an automatic torque biasing (ATB) differential (Or Torsen, as others have already mentioned), and are a really nice upgrade over an open diff on (fast)road applications, especially on FWD cars! However, in RWD rally/drifting setups, a traditional plate LSD simply can not be beaten in terms of controllability, since you actually want both wheels locked together in those conditions when you're right foot steering so to speak...
It works extremely well with traction control because even if you get a wheel in the air will transfer more torque than an open differential would have
I make gear and pinion blanks for limited slip diffs and other fancy aftermarket and industrial sorts for some folk other than torsen (think select-a-loc). Its really neat to see how diffs and, by extension, the other stuff I make work because I just run cnc and don't really have much actual mechanical knowledge.
For a video titled "how it works", there's absolutely no explanation of how it works. It basically boils down to "This is a limited slip differential. Cool, right?" Yeah, but how does it work? How does it help?
I love the attempt at cinematic camera pans at the end, just a note though. for speed matching a rotation at 3:09 it's better to place the camera so the center of the image is perpendicular to the axis of rotation and you can then handle the rotation in editing later on. Place the camera further back to account for the zoom out and the fact that the image is rectangular. as for the rest, good work!
Cool video. You left me wanting to know more about how and why this design works the way it does, though. As in, what about its unique arrangement leads to the torque being distributed the way it does when the "loose" wheel has at least a small amount of friction, and by contrast, why a "basic" differential DOESN'T do that.
Yep, the video fails to explain the behaviour of the differential, but we can see the construction and behaviour, of which the last seems identical to regular differential as a wheel can be completely halted, making the other wheel spin faster... I'm not convinced that the displayed model works at all as intended. I've seen a video of a Lego-model Torsen differential, that used worm gears, which can't be turned by the main axles, but now I'm thinking that the Lego-model had flawed operation too... :D
Torsion diff take advantage of worm gear effect. You can turn the screw to rotate a gear but turning the gear doesn't want to turn the worm. A small amount of load on the spinning wheel effectively locks up the worm gear which powers both wheels. Normal limited slip is just a clutch between both axles. There is also viscous couplers and automatically locking diffs
He did mention the principal of operation, though breifly. It relies on the helical angle of the "worms" being steep enough that they can only pass motion in one direction i.e. the pinion can not drive the worm gear, but the worm gear can drive the pinion.
Great model and explanation. I've always been fascinated by any type of differential, and my 1995 NA8 Miata has this exact type of Torsen (short for TORque SENsitive) differential, which is a superb diff.
i would have liked to see more on piece by piece how one wheel slipping creates torque to the wheel thats not. but ive spent over a grand installing one of these on my truck so my interest of further explanation might just be above my head of understanding. if that makes sense.... still a well made video.
I think the helical gear arrangement is inherently having greater friction than pinion and spur type. It is this friction that provide some braking force on the side that start spinning freely so you don't need to step on the brake.
@@Tymeshifter no its not friction its gear bias. Friction is a plate LSD which basically is a ramped clutch with multiple disks. For off road trucks you don't want an LSD, but a simple locker, as on dirt the low friction surface gives you the differential action you need while keeping the axles locked. With a LSD off-road and a wheel in the air, you are now stuck as a LSD must have some traction on both wheels or nothing happens. On-road, LSD. Off-road, locker.
@@spinnetti wait really? i always thought the clutch diffs always locked spinning wheel (or as close as the plates can get to “locking”) regardless if the particular wheel’s in the air or on gravel or whatever.
Gears, in general, are a very simple but very clever invention. Using the right gears in the right application makes so many things possible or difficult things easier.
Correct me if I'm wrong, but aren't they supposed to be worm gears, instead of helical gears? I thought the entire point of this type of differential was that no wheel is allowed to 'lose' torque, due to the worm wheel's one-way drive property. As in: one wheel is only allowed to spin slower if the other wheel is being spun faster by the turn, instead of being driven by the differential. And if that is true: holding one wheel in place actually locks the differential, since the worm wheel won't be turned by the axle. While if one wheel is being forced to spin faster (due to turn), THEN the differential starts spinning.
@@markbickford9092 perfectly explained! The fact that the opposite wheel spun faster when he held one still means the worm gear isn't steep enough to actually act as a worm gear. This original vid is just an open diff. without any sort of limited slip at all.
@@didiwin78 Technically it's a type of LSD called a torsion differential. Most LADS are clutch based. This one effectively varies the gear ratio between the two wheels so that if one wheel spins faster the other one gets a higher effective ratio and therefore more torque at the wheel. The only problem is that it still relies on both wheels getting traction like an open diff, so if one wheel gets zero traction, the other gets zero torque. It's an improvement on the open differential, but a true LSD can completely lock the differential if needed. I believe modern ones can also be electronically controlled, like on the Subaru WRX STi I had, which had quite a few settings for different torque splits
@@didiwin78 Technically it's a type of LSD called a torsion differential. Most LSDs are clutch based. This one effectively varies the gear ratio between the two wheels so that if one wheel spins faster the other one gets a higher effective ratio and therefore more torque at the wheel. The only problem is that it still relies on both wheels getting traction like an open diff, so if one wheel gets zero traction, the other gets zero torque. It's an improvement on the open differential, but a true LSD can completely lock the differential if needed. I believe modern ones can also be electronically controlled, like on the Subaru WRX STi I had, which had quite a few settings for different torque splits and could go full diff lock as well.
@@didiwin78 Incorrect. Irrespective of the torque split (helical angle) a torque biasing differential does not provide any limited slip action if one wheel is completely open which is what he demonstrated. This is the weakness of this type of differential, but it offers advantages over plate type diffs that do handle one open wheel (e.g. less tyre wear, no plate wear, no impact on vehicle dynamics when cornering where strong plate diffs can cause understeer).
These Torsen/helical LSDs are pretty good, but when one wheel has essentially zero grip, it gets essentially all the torque. Very noticeable off-road, or negotiating driveways with a weird gutter that allows one wheel to come off the ground. The HMMWV (humvee) has Torsens diffs; the instruction manual explains to apply brakes in slippery conditions - the brakes add artificial grip to the wheel with zero grip - which forces the differential to direct torque that way.
It works extremely well with traction control because even if you get a wheel in the air will transfer more torque than an open differential would have. So basically the torque bias effect will multiply the torque coming from Spinning Wheel win the brake grabs then it would have from the spinning wheel of an open diff. So let's say open diff with 1:1 ratio bias spins and the brake grabs and it sends 50 lb over to the gripping wheel well with this 3:1 ratio it will grab with 50 lb and send 150 over. When you press the brake pedal it's not as effective because you're also adding brake Force to the wheel with grip. That's why ABS traction control works super well with these do you know what the wheel in the air. Especially if you put it on something that has a really strong traction control even with open diffs like Land Rover Disco or Range Rover from the 90s and 2000s
Not saying I know everything but I wish I wasn't a car guy so when I watched these vids it was something new... doesn't mean it's a bad vid, great vid, thumbs up here
I think this video failed to provide the “why”. You said The genius is that it is a mechanical system that transfers the correct amount of torque to the wheel that needs it most. I was expecting you then to explain why it does that, and that was the end. I honestly dont know why these gears aligned in this way perform that function.
The limited slip that has been around since the 60’s is different, it uses clutches. That’s a Gleason. A far cry from a limited slip. But superior and three times the price.
I appreciate what you do to help people understand cool things like this. May I ask that the music track be at a lower volume though? I have trouble focusing on the words being said, especially around the @1:05 mark.
@@3DPrinterAcademy Thank you! For extra clarification, it's worse with some headphones. Cheaper ones make the problem worse, but I still run into this here and there. Thanks for your consideration. :)
You showed how it is built, but not how it works. The geometry of the helical gear is such that the greater load the greater the friction between the helical gears. The ratio between the two is proportional to the angle of the teeth cut in the gear mesh.
This is an awesome model and I’d like to print it using my homemade PET filament made from recycled water bottles. Is this model available to download from somewhere?
@@spinnetti Well I'm no expert and I'm not tryna discredit you, but isn't the whole thing with torsen diffs is that they lock up mechanically in situations where one wheel has less traction?
It works extremely well with traction control because even if you get a wheel in the air will transfer more torque than an open differential would have
Yes imagine if the blue gears were made with tiny rollers like a steering rack then it would just be a very complicated diff. But similar to worm gears they lock against each other when the torque is unequal Like having rubbish gear box that keeps locking up. But if they were more aggressively pitched like worm gears then they would be locked all the time and have no differential action under normal loads. but in the mud the vehicle is still loaded a little on the wheel that wants to slip. If you had a hanging wheel (rock crawling) then it would also fail as there would be no resistance to activate locking. The solution there is to touch the brakes a little and then you would get moving again.
Thanks for the video. In my car I have a Quaife helical geared LSD, your video shows why it feels the way it does. It really works like magic! Flooring it around a corner the power just goes to whichever wheel needs it more, blows me away every time. Quaife call it "automatic torque biasing" (ATB). It certainly was more expensive than welding the diff, but it is amazing!
@@krisg822 it does do good for FWD. My dad and I do lanes rallies in a Vauxhall Nova. We have a torque bias in it and it's an amazing job. Most LSDs that go in FWD cars give it a lot of understeer in tight corners but the torque bias doesn't do that and it pulls so well
@@jackstewart7664 not sure how it's called, but there is a thing like 'Xdif' , it uses ABS to brake one wheel in order for the diff to do the rest of the job. Some cars that claim AWD use it too, altho, AWD is only real with with either torsen or locked differentials. Anyway, for FWD the xdif does not a bad job, it lags somewhat behind, and won't get the car out of mud or snow, but once tha car is moving , it does it's magic.
Eaton makes these for a wide range of applications. The Detroit TruTrac. It's an amazing upgrade for vehicles that see a lot of mud, dirt, gravel, or snow. I run one in the rear of my Jeep Wrangler.
Torsen diffs can potentially make traction control systems work much better by multiplying the torque sent to the non slipping wheel. If setup correctly, they can provide even more traction than locked differentials in certaim scenarios.
this just reminds me, i need a new front diff for my ftx rokatan....i blew up my front diff, at least thats what i suspect, gonna get a better look in a few hours....
Could i pay you to print a gearbox for a windmill generator but i would like to have it to when the props moves say 4 or 6 times the connection to the generator is spinning very very fast i want to maximize the most rpms in the generator. If you could print individual parts ill have them cast in iron .or do you know where i can find such a gearbox in a scrapyard or junkyard and whats it's connected to. Im hoping for 6ft prop blades .any help would be appreciated thankyou.
I don’t think they wear at all because it is essentially the worst gear box ever. By designed to run true with equal load but locks up when the load is unequal So there is no moving parts under pressure when controlling the torque.
It runs in oil just like the bevel gears of a regular open diff, why would wear be a problem? Wear _is_ a problem for plate type LSDs which require special oil and rebuilds when the plates wear.
Nice explanation of limited slip with a open diff. You could've gone deeper though into how the car knows when to apply the brake on the wheel that's slipping.
The rendering you have at @0:55 is actually more confusing that you give it credit for: what's rendered does not work as a differential! The two halves are symmetric, so you can spin both wheels in the same direction and they will happily spin together without the carrier moving, and conversely the carrier can spin freely without wheels moving. Thankfully, your 3D print is correct, but you'll note that it's not symmetric the way the rendering is. The symmetrical design in the rendering can be made into a proper differential by separating the two halves and adding a third spur gear between each pair being separated. This makes the two original spur gears rotate the same direction rather than counter rotate. The third spur gear in between serves the same purpose as the spider gear in an open differential.
So neither the Torson, or the Trutrac, are actual Lockers. They need some kind of resistance from the spinning wheel to bind up the gears to make them work
Fantastic, is it possible to build this differential system with Lego pieces, say with Spike prime or else? If yes, please share a link. Thank you so much.
I understand the concept, however I didn't get the quote "send power to the wheel that needs it", shouldn't that be "send more power to the wheel that can use it". (other wheels spinning ) ???????
This is actually more than limited slip, because the locking action is instantaneous, so the limited slip differential allows one wheel to slip for a limited time and then lock, so a limited slip differential is a lot complicated than a torsen differential.
@@Matt_10203 build quality seems really good as well. got mine as a handmedown, dad hasnt been having fun setting up his crazy 2 nozzle setup. apparently the frame (not bed) of the thing was assembled do dickheadishly it would just never zero properly. id definitely say ender 3 is a great starting printer. remove the bowden system if you wanna upgrade, or go crazy on a resin printer or whatever when you figure shit out. but still keep the ender. it always works for whater reason
Felt like it ended half way through the video, definitely a good video but more explanation seems necessary for the consept to sink in properly. I think I understand but I don't feel confident with the amount of information provided.
when the differential uses a worm gear, if the vehicle is going fast, then the engine speed decreases while the potential energy of the vehicle is still high, will the wheels not lock and then slip?
Makes no sense that you did not construct this like an ACTUAL differential. Over-complicated and just ads confusion due to the increased part count. Why????
Thank you for good video for understanding Torsen differential. But to my eyes the teeth direction of the red helical gears and blue worm gears in the 3D graphic are opposite direction and this is weird, they should have the same direction left to right to work properly as the way you made them in real.
Why not just use a traditional plate style lsd and save the extra moving parts and size? Also I doubt this design will be very strong depending on the cost. Although the title is correct. The mechanism is seriously cool.
2:48 "... instantaneously transfers the correct amount of torque to the wheel that needs it the most" That's exactly what it DOES NOT do. It's even proven by your own very demo. If one wheel is free-spinning in the mud and the other has all the traction to the road it would just keep spinning in the mud.
As he said, even on ice you have some traction/resistance that would be enough to trigger the locking mechanism. The problem is when one tyre is not touching the ground, then it acts as an open diff.
You should pay more attention. It biases torque to the wheel that needs it the most, but it requires that some torque still go through the wheel with the least traction. If one wheel is completely open then it works like an open diff, which is the only real disadvantage of this type of diff. However there is a workaround for low speed low grip situations e.g. trying to pull away with one tyre on mud or ice, by lightly applying the vehicles brakes you provide some torque resistance on the open wheel allowing the diff to apply torque to the wheel with more traction.
@@ferrumignis Fair enough. Your explanation makes more sense. I just feel like it wasn't clearly explained in the video or requires prior knowledge of the operation of the diff to get it. I had to look up Torsen diff to fully understand it.
This video feels AI generated. Hits all the notes but hits some too many times, and hits some too early. Purely from a film design/editing perspective this is third year stuff, keep improving 👍
Yes and no. Electronics can be used as a crutch and often are, but mechanical parts have their properties set in steel when they're made so to speak. If you need the diff to behave differently to account for different road conditions or driving style, you'll have to build and install a new one (the relative sizes of the blue and red gears change the exact minimum torque required to initiate the locking behavior, for instance). An electronic diff can be re-mapped for track/off-road/regular use with the flip of a switch. Also lets you account for steering wheel angle and suspension state along with lateral loads and a bunch of other things. If it's an all-wheel-drive car, this includes the gearbox changing how much power is going front to back as well.
The key to this differential is the fact that a worm gear can turn a spur gear but the spur gear cannot turn the worm gear. So it acts like a mechanical diode.
Which in a car is generally a bad thing
@@gizelle-s How is that a bad thing?
"Mechanical diode" is a very good analogy, I'll be stealing that, thank you.
@@erikkovacs3097 when the engine is off and the car is moving, rotation from the wheels is transferred to the defferential then to the disengaged transmission, if I'm correct then the differential has to break or the car stop moving
where is the worm gear in this differential?
Great print, did not explain why a torsen is limited slip instead of just a fancy open
In many ways, a torsen is often referred to as a fancy open diff. A clutch based limited slip, which is the most common LSD, is capable of locking the left and right axles together. The Torsen LSD is often referred to as a "torque multiplier" because it uses the spur gears to multiply the amount of torque one wheel gets, when the other wheel starts slipping. You can see the torque multiplication effect in the video when one wheel spins faster because the other wheel is stopped.
In certain conditions, the Torsen diff won't work when the spinning wheel has zero traction, because it can't multiply zero torque.
Because of that, and other reasons such as driver preference, more traditional LSD setups are preferred in racing or off-road applications.
If you want to get technical, it is a limited slip. While it can't solve the zero traction problem, it does try to ensure that 100% of the power is being used between both wheels (barring things like friction in its own operation) while an open diff is always just 50/50 split regardless.
@@markbickford9092 very good video. Once he said “the worm gear can turn the spur gear but not the other way around” it twigged in my head. Very clever. In practice I think the slope of the teeth means that one gear isn’t 100% spur and the other 100% worm, but changing that slope influences the torque threshold.
@@YoRHaAttackerNo2 except that the Torsen diff is not just a torque splitter, it's a torque multiplier.
Going back to the open diff, it's commonly said that it always have a 50/50 split. What that means is that if the spinning wheel only can handle 25 ft-lbs of torque before spinning, then the stationary wheel would receive 25 ft-lbs of torque.
Now take the Torsen with the same example. If the diff is rated for 3x torque bias ratio, then the stationary wheel would receive 75 ft-lb of torque if the spinning wheel can only handle 25 ft-lbs. This would be a variable 25/75 torque split, depending on the situation.
This variability is a major reason why Torsens aren't always used in racing or off-road applications. In comparison, a clutch LSD would be sending up to 100% of the input torque to a single wheel if needed, or a max of a 0/100 torque split.
@@patx35
That and the clutch LSD can force a 50/50 split in a zero traction situation.
Very important to mention that this is a torsen differential in my opinion. When someone thinks of a limited slip differential it is not typically this differential, it would most likely be a plated limit slip differential as this is the most common seen in cars today. Not many manufactures use torsen diffs, they see the most use in audi's though.
Torsen was the only limited slip offered in the miata from 94 to 2003, and it is a limited slip in every sense of the word. Seems you lack experience.
You don't just get to redefine things as you see fit, amber turd.
That is in part due to a patent on this design if I recall correctly. Not sure if that's expired yet.
This type of diff is generally used in WRC and other rally categories
I mean, clutch LSDs may be more common overall, but I don't know if any modern car has one of those- helical (like Torsen) and viscous LSDs seem to be the only ones in production vehicles.
Yeah there's some things the author could mention, but it's also a heck of a rabbit hole, haha.
I replaced my worn out clutch style with Torsen, drives much better and will never need a rebuild. As far as traction, it performs smoother than my clutch style LSD. Defenetly a bit more expensive and you lose a little efficiency hence the factory not putting them in many vehicles.
Just want to say, your 3D print color combos recently have been terrific.
Thanks! :)
this type of LSD is known as a torsen differential 🤠
That's right!
Exactly what I was about to say. Strange how they didn't mention this in the video
I like LSD
I took a torsen differential in a party
I'll have to ask my dealer about it next time i see them
This is also referred to as an automatic torque biasing (ATB) differential (Or Torsen, as others have already mentioned), and are a really nice upgrade over an open diff on (fast)road applications, especially on FWD cars!
However, in RWD rally/drifting setups, a traditional plate LSD simply can not be beaten in terms of controllability, since you actually want both wheels locked together in those conditions when you're right foot steering so to speak...
It works extremely well with traction control because even if you get a wheel in the air will transfer more torque than an open differential would have
We live in age where computers can do so much. We’ve lost appreciation for how ingenious - and reliable - mechanical devices can be
I make gear and pinion blanks for limited slip diffs and other fancy aftermarket and industrial sorts for some folk other than torsen (think select-a-loc). Its really neat to see how diffs and, by extension, the other stuff I make work because I just run cnc and don't really have much actual mechanical knowledge.
For a video titled "how it works", there's absolutely no explanation of how it works. It basically boils down to "This is a limited slip differential. Cool, right?" Yeah, but how does it work? How does it help?
I love the attempt at cinematic camera pans at the end, just a note though. for speed matching a rotation at 3:09 it's better to place the camera so the center of the image is perpendicular to the axis of rotation and you can then handle the rotation in editing later on. Place the camera further back to account for the zoom out and the fact that the image is rectangular. as for the rest, good work!
Cool video. You left me wanting to know more about how and why this design works the way it does, though. As in, what about its unique arrangement leads to the torque being distributed the way it does when the "loose" wheel has at least a small amount of friction, and by contrast, why a "basic" differential DOESN'T do that.
Me too. I still don't understand why this one is so special compared to a normal diff
Yep, the video fails to explain the behaviour of the differential, but we can see the construction and behaviour, of which the last seems identical to regular differential as a wheel can be completely halted, making the other wheel spin faster... I'm not convinced that the displayed model works at all as intended.
I've seen a video of a Lego-model Torsen differential, that used worm gears, which can't be turned by the main axles, but now I'm thinking that the Lego-model had flawed operation too... :D
Torsion diff take advantage of worm gear effect. You can turn the screw to rotate a gear but turning the gear doesn't want to turn the worm.
A small amount of load on the spinning wheel effectively locks up the worm gear which powers both wheels.
Normal limited slip is just a clutch between both axles.
There is also viscous couplers and automatically locking diffs
Engineering explained has a decent breakdown of torsion diffs
He did mention the principal of operation, though breifly. It relies on the helical angle of the "worms" being steep enough that they can only pass motion in one direction i.e. the pinion can not drive the worm gear, but the worm gear can drive the pinion.
I’ve always wondered how these worked, your animations and model made it all make sense. Thanks
Great model and explanation. I've always been fascinated by any type of differential, and my 1995 NA8 Miata has this exact type of Torsen (short for TORque SENsitive) differential, which is a superb diff.
i would have liked to see more on piece by piece how one wheel slipping creates torque to the wheel thats not. but ive spent over a grand installing one of these on my truck so my interest of further explanation might just be above my head of understanding. if that makes sense.... still a well made video.
I think the helical gear arrangement is inherently having greater friction than pinion and spur type. It is this friction that provide some braking force on the side that start spinning freely so you don't need to step on the brake.
With a small enough helical angle on the worm gear, the worm can drive the pinion but the pinion cannot drive the worm.
@@Tymeshifter no its not friction its gear bias. Friction is a plate LSD which basically is a ramped clutch with multiple disks. For off road trucks you don't want an LSD, but a simple locker, as on dirt the low friction surface gives you the differential action you need while keeping the axles locked. With a LSD off-road and a wheel in the air, you are now stuck as a LSD must have some traction on both wheels or nothing happens. On-road, LSD. Off-road, locker.
Found a UA-cam video explain how it works: ua-cam.com/video/JEiSTzK-A2A/v-deo.html
@@spinnetti wait really? i always thought the clutch diffs always locked spinning wheel (or as close as the plates can get to “locking”) regardless if the particular wheel’s in the air or on gravel or whatever.
Being a Miata driver of over 22 years now, I recognized the Torsen differential immediately from the thumbnail.
Torsen differential was a genius invention and you implementation excellent!
Great video!
Gears, in general, are a very simple but very clever invention. Using the right gears in the right application makes so many things possible or difficult things easier.
This is the type channel i been looking for since i leanred about 3d printing, thank you for your effort and time
Where are the files for this design? I clicked the link in the description and it brings me to a 404 page…
*Finally* after all these years, a video demonstrating the Torsen differential thoroughly 👍 Thank you
...but not explaining how it works!
@@altair7001 yeah thats pretty strange not to do when you first make a video like this
nah. "thoroughly" is not the word you were searching for ;) "just a bit" fits much better.
Thanks for the clip!!!! I think the most important parts is operations at 2:02 which shown how this type of LSD response.
Great video! Just found your channel! Very excited! Subbed!
Around The Corner - How Differential Steering Works (1937)
It's the video all of us have already watched or need to watch.
Correct me if I'm wrong, but aren't they supposed to be worm gears, instead of helical gears? I thought the entire point of this type of differential was that no wheel is allowed to 'lose' torque, due to the worm wheel's one-way drive property. As in: one wheel is only allowed to spin slower if the other wheel is being spun faster by the turn, instead of being driven by the differential.
And if that is true: holding one wheel in place actually locks the differential, since the worm wheel won't be turned by the axle. While if one wheel is being forced to spin faster (due to turn), THEN the differential starts spinning.
@@markbickford9092 perfectly explained! The fact that the opposite wheel spun faster when he held one still means the worm gear isn't steep enough to actually act as a worm gear. This original vid is just an open diff. without any sort of limited slip at all.
@@didiwin78 Technically it's a type of LSD called a torsion differential. Most LADS are clutch based. This one effectively varies the gear ratio between the two wheels so that if one wheel spins faster the other one gets a higher effective ratio and therefore more torque at the wheel. The only problem is that it still relies on both wheels getting traction like an open diff, so if one wheel gets zero traction, the other gets zero torque. It's an improvement on the open differential, but a true LSD can completely lock the differential if needed. I believe modern ones can also be electronically controlled, like on the Subaru WRX STi I had, which had quite a few settings for different torque splits
@@didiwin78 Technically it's a type of LSD called a torsion differential. Most LSDs are clutch based. This one effectively varies the gear ratio between the two wheels so that if one wheel spins faster the other one gets a higher effective ratio and therefore more torque at the wheel. The only problem is that it still relies on both wheels getting traction like an open diff, so if one wheel gets zero traction, the other gets zero torque. It's an improvement on the open differential, but a true LSD can completely lock the differential if needed. I believe modern ones can also be electronically controlled, like on the Subaru WRX STi I had, which had quite a few settings for different torque splits and could go full diff lock as well.
@@didiwin78 Incorrect. Irrespective of the torque split (helical angle) a torque biasing differential does not provide any limited slip action if one wheel is completely open which is what he demonstrated. This is the weakness of this type of differential, but it offers advantages over plate type diffs that do handle one open wheel (e.g. less tyre wear, no plate wear, no impact on vehicle dynamics when cornering where strong plate diffs can cause understeer).
These Torsen/helical LSDs are pretty good, but when one wheel has essentially zero grip, it gets essentially all the torque. Very noticeable off-road, or negotiating driveways with a weird gutter that allows one wheel to come off the ground. The HMMWV (humvee) has Torsens diffs; the instruction manual explains to apply brakes in slippery conditions - the brakes add artificial grip to the wheel with zero grip - which forces the differential to direct torque that way.
It works extremely well with traction control because even if you get a wheel in the air will transfer more torque than an open differential would have. So basically the torque bias effect will multiply the torque coming from Spinning Wheel win the brake grabs then it would have from the spinning wheel of an open diff. So let's say open diff with 1:1 ratio bias spins and the brake grabs and it sends 50 lb over to the gripping wheel well with this 3:1 ratio it will grab with 50 lb and send 150 over. When you press the brake pedal it's not as effective because you're also adding brake Force to the wheel with grip. That's why ABS traction control works super well with these do you know what the wheel in the air. Especially if you put it on something that has a really strong traction control even with open diffs like Land Rover Disco or Range Rover from the 90s and 2000s
Oh no did you remove the STL files? I wanted to print this! Can you upload again? The link gives 404.
Not saying I know everything but I wish I wasn't a car guy so when I watched these vids it was something new... doesn't mean it's a bad vid, great vid, thumbs up here
I think this video failed to provide the “why”. You said The genius is that it is a mechanical system that transfers the correct amount of torque to the wheel that needs it most. I was expecting you then to explain why it does that, and that was the end. I honestly dont know why these gears aligned in this way perform that function.
Had this diff on my b6 a4 1.9 tdi. It was the Quattro Sport Version. So much fun I’m the snow haha.
Man, that one very Genius design. Nice man good job.
The limited slip that has been around since the 60’s is different, it uses clutches. That’s a Gleason. A far cry from a limited slip. But superior and three times the price.
Nifty idea. Liked the clip and the explanation.
I recommend the video "Spinning levers" and "Around the corner" an old Chevrolet commercial that outranks any modern car ad in being a good lesson.
I appreciate what you do to help people understand cool things like this. May I ask that the music track be at a lower volume though? I have trouble focusing on the words being said, especially around the @1:05 mark.
Thank you for the time stamp! I will adjust for future videos!
@@3DPrinterAcademy Thank you! For extra clarification, it's worse with some headphones. Cheaper ones make the problem worse, but I still run into this here and there. Thanks for your consideration. :)
Great video! Music is a tad to intrusive for my taste. Thanks for the very understandable explanation :D
You showed how it is built, but not how it works. The geometry of the helical gear is such that the greater load the greater the friction between the helical gears. The ratio between the two is proportional to the angle of the teeth cut in the gear mesh.
Yeah, the video lacked any kind of explanation
This is an awesome model and I’d like to print it using my homemade PET filament made from recycled water bottles. Is this model available to download from somewhere?
You can download it on my website www.3DPrinterAcademy.com search for 'Torsen'
@@3DPrinterAcademy thanks! If I make this, I’ll be sure to share my success (or failure perhaps) with you.
tolles beispiel , man kann sich so sehr gut vorstellen wie ein zentral torsen bei belastung selbstätig sperrt .
"How does a LSD work?"
"Because it can send torque to a wheel with no grip?"
"But how does it do that?"
"Because it is a LSD"
it actually can't send torque to the wheel with no grip..it will just spin like an open diff in that case.
@@spinnetti Well I'm no expert and I'm not tryna discredit you, but isn't the whole thing with torsen diffs is that they lock up mechanically in situations where one wheel has less traction?
It works extremely well with traction control because even if you get a wheel in the air will transfer more torque than an open differential would have
this is gold
But HOW or WHY does adding a tiny bit of friction make all the power go to the tire that needs it most?
Yes imagine if the blue gears were made with tiny rollers like a steering rack then it would just be a very complicated diff.
But similar to worm gears they lock against each other when the torque is unequal
Like having rubbish gear box that keeps locking up.
But if they were more aggressively pitched like worm gears then they would be locked all the time and have no differential action under normal loads.
but in the mud the vehicle is still loaded a little on the wheel that wants to slip.
If you had a hanging wheel (rock crawling) then it would also fail as there would be no resistance to activate locking.
The solution there is to touch the brakes a little and then you would get moving again.
Thanks for the video. In my car I have a Quaife helical geared LSD, your video shows why it feels the way it does. It really works like magic! Flooring it around a corner the power just goes to whichever wheel needs it more, blows me away every time.
Quaife call it "automatic torque biasing" (ATB). It certainly was more expensive than welding the diff, but it is amazing!
@@jeremyroper7273 Holden Gemini.
ua-cam.com/users/clipUgkx6lmbH14j8DiW18L1RJNmrn9WtSo3YRjC
1:22.. that didn't actually explain the reason one wheel spins faster. It seems like there was some missing info there.
I've heard it been called a torque bias differential. It's a great option for FWD cars
nope, this will not do anything good in FWD, it was made for AWD, specifically for AUDI Quattro
@@krisg822 it does do good for FWD. My dad and I do lanes rallies in a Vauxhall Nova. We have a torque bias in it and it's an amazing job. Most LSDs that go in FWD cars give it a lot of understeer in tight corners but the torque bias doesn't do that and it pulls so well
@@jackstewart7664 not sure how it's called, but there is a thing like 'Xdif' , it uses ABS to brake one wheel in order for the diff to do the rest of the job. Some cars that claim AWD use it too, altho, AWD is only real with with either torsen or locked differentials.
Anyway, for FWD the xdif does not a bad job, it lags somewhat behind, and won't get the car out of mud or snow, but once tha car is moving , it does it's magic.
@@krisg822 I think the gold gti uses that system. Or atleast something similar. Our Vauxhall Nova is far too old for something like that however
@@krisg822😂 just because Audi puts one of those in the transfer case you get excited and think that that's the only place it works
Eaton makes these for a wide range of applications. The Detroit TruTrac. It's an amazing upgrade for vehicles that see a lot of mud, dirt, gravel, or snow. I run one in the rear of my Jeep Wrangler.
for the center diff im sure, not the front or rear lol
@@theinsivibleman5309 you need to do some research. The example shown in this video is not the only form of a Torsen limited slip.
@@wvjeepguy8178 ah i see, my bad then.
Cheers for the upload
I finally learnt how an lsd works. Very cool.
"It's actually really simple" - proceeds to demonstrate a Torsen diff operating identically to an open differential
This is one of those things that sounds cool even though you don't understand what it's for, and then when you get it you go "Woah..."
Torsen diffs can potentially make traction control systems work much better by multiplying the torque sent to the non slipping wheel. If setup correctly, they can provide even more traction than locked differentials in certaim scenarios.
Cool!
Can you upload the STL file again, please?
this just reminds me, i need a new front diff for my ftx rokatan....i blew up my front diff, at least thats what i suspect, gonna get a better look in a few hours....
Cool model. Thank you.
The Music behind ist so great, i cant understand a singel word, thanks.
I’ve always loved your videos, but you didn’t explain how it works, just what it does. ???
Could i pay you to print a gearbox for a windmill generator but i would like to have it to when the props moves say 4 or 6 times the connection to the generator is spinning very very fast i want to maximize the most rpms in the generator. If you could print individual parts ill have them cast in iron .or do you know where i can find such a gearbox in a scrapyard or junkyard and whats it's connected to. Im hoping for 6ft prop blades .any help would be appreciated thankyou.
I’ve definitely seen a design like this in a LEGO when i was a kid
This design is really cool. I want to print one for my child. How can I buy stl?❤
Solid print!
How about wear of the gears?
I would also love to know the answer to this question, and many more, but I would be happy to start here
I don’t think they wear at all because it is essentially the worst gear box ever.
By designed to run true with equal load but locks up when the load is unequal
So there is no moving parts under pressure when controlling the torque.
It runs in oil just like the bevel gears of a regular open diff, why would wear be a problem? Wear _is_ a problem for plate type LSDs which require special oil and rebuilds when the plates wear.
Hello, can you please update the STL file?
Nice explanation of limited slip with a open diff. You could've gone deeper though into how the car knows when to apply the brake on the wheel that's slipping.
Could you upload the files? I'd really like to print it
Are you based in Orange County? Looks like the Microcenter in Tustin
Your explanations are always so straightforward keep up the good work
Are the STL files no longer available?
can you make an air powered engine 3d printed? with a 3 speed transmission and electric starter
The rendering you have at @0:55 is actually more confusing that you give it credit for: what's rendered does not work as a differential! The two halves are symmetric, so you can spin both wheels in the same direction and they will happily spin together without the carrier moving, and conversely the carrier can spin freely without wheels moving.
Thankfully, your 3D print is correct, but you'll note that it's not symmetric the way the rendering is.
The symmetrical design in the rendering can be made into a proper differential by separating the two halves and adding a third spur gear between each pair being separated. This makes the two original spur gears rotate the same direction rather than counter rotate. The third spur gear in between serves the same purpose as the spider gear in an open differential.
this style is torque biasing, so if one wheel is in the air, you still have no traction.
Yes so touch the brakes a little and you get moving again.
You should submit this design for the Printables Contest Mechanical Marvels. This could be the winner. First price is a Prusa i3 MK3S+ kit.
What is the purpose of the blue gears coming in 3 sets?
So neither the Torson, or the Trutrac, are actual Lockers.
They need some kind of resistance from the spinning wheel to bind up the gears to make them work
Fantastic, is it possible to build this differential system with Lego pieces, say with Spike prime or else? If yes, please share a link. Thank you so much.
I love Torsen diffs.
I understand the concept, however I didn't get the quote "send power to the wheel that needs it", shouldn't that be "send more power to the wheel that can use it". (other wheels spinning ) ???????
My '95 NA Miata M-Edition has this Torsen differential.
This is actually more than limited slip, because the locking action is instantaneous, so the limited slip differential allows one wheel to slip for a limited time and then lock, so a limited slip differential is a lot complicated than a torsen differential.
But if the other tire is not touching the ground this would act as a open differential? But ive sen torsen doesnt so that.
As the owner of and ender 3 I use it as my go-to printer even over my $700 printers
It’s very customisable that’s for sure.
@@Matt_10203 build quality seems really good as well. got mine as a handmedown, dad hasnt been having fun setting up his crazy 2 nozzle setup. apparently the frame (not bed) of the thing was assembled do dickheadishly it would just never zero properly. id definitely say ender 3 is a great starting printer. remove the bowden system if you wanna upgrade, or go crazy on a resin printer or whatever when you figure shit out. but still keep the ender. it always works for whater reason
Felt like it ended half way through the video, definitely a good video but more explanation seems necessary for the consept to sink in properly. I think I understand but I don't feel confident with the amount of information provided.
when the differential uses a worm gear, if the vehicle is going fast, then the engine speed decreases while the potential energy of the vehicle is still high, will the wheels not lock and then slip?
Nope, It behaves indistinguishable from an open diff in that regard. This version is harder to visualize then earlier versions.
Can you share the parameters that you have taken ,it's helps a lot.
Makes no sense that you did not construct this like an ACTUAL differential. Over-complicated and just ads confusion due to the increased part count. Why????
I dont understand how the power gets equally distrbuted(and why will the red gear spin if u stop a wheel)
3:00 i remember this music from chernobil izotopium game it used to play in background it was pc only game but i played it on phone lol
Thank you for good video for understanding Torsen differential.
But to my eyes the teeth direction of the red helical gears and blue worm gears in the 3D graphic are opposite direction and this is weird, they should have the same direction left to right to work properly as the way you made them in real.
Anyone know what the song is? (great video too btw thanks)
Why not just use a traditional plate style lsd and save the extra moving parts and size? Also I doubt this design will be very strong depending on the cost. Although the title is correct. The mechanism is seriously cool.
Cool video
2:48 "... instantaneously transfers the correct amount of torque to the wheel that needs it the most" That's exactly what it DOES NOT do. It's even proven by your own very demo. If one wheel is free-spinning in the mud and the other has all the traction to the road it would just keep spinning in the mud.
As he said, even on ice you have some traction/resistance that would be enough to trigger the locking mechanism. The problem is when one tyre is not touching the ground, then it acts as an open diff.
You should pay more attention. It biases torque to the wheel that needs it the most, but it requires that some torque still go through the wheel with the least traction. If one wheel is completely open then it works like an open diff, which is the only real disadvantage of this type of diff. However there is a workaround for low speed low grip situations e.g. trying to pull away with one tyre on mud or ice, by lightly applying the vehicles brakes you provide some torque resistance on the open wheel allowing the diff to apply torque to the wheel with more traction.
@@ferrumignis Fair enough. Your explanation makes more sense. I just feel like it wasn't clearly explained in the video or requires prior knowledge of the operation of the diff to get it. I had to look up Torsen diff to fully understand it.
Great video, but the background music makes it difficult to understand you.
Your mechanical vocabulary is atrocious, but your principals are spot on
Torque converter baby. I’ll be printing the shit out of this in resin. Just because.
Where can I find the print files
Its not his design. It is from thingiverse and he doesn't credit he creator.
the 1950s video is much simpler and easier to understand
This video feels AI generated. Hits all the notes but hits some too many times, and hits some too early. Purely from a film design/editing perspective this is third year stuff, keep improving 👍
Thank you 🙏🏽
So very awesomely explained, thank you!
Mechanical parts are pretty reliable when well designed. I've always seen electronics as a way to compensate for non-ideal designs.
Yes and no. Electronics can be used as a crutch and often are, but mechanical parts have their properties set in steel when they're made so to speak. If you need the diff to behave differently to account for different road conditions or driving style, you'll have to build and install a new one (the relative sizes of the blue and red gears change the exact minimum torque required to initiate the locking behavior, for instance).
An electronic diff can be re-mapped for track/off-road/regular use with the flip of a switch. Also lets you account for steering wheel angle and suspension state along with lateral loads and a bunch of other things. If it's an all-wheel-drive car, this includes the gearbox changing how much power is going front to back as well.
@@DFX2KX That's the point. If it can be mechanical and needs no change, why make it electronic if it will requiremore maintenance?