This is a masterpiece of engineering!! It’s the culmination of the CVT principle, without the friction issues of a CVT, in a smaller/lighter package than any other transmission, incorporating hybrid electrical drive/generation systems, into an extremely reliable transmission… which is scalable, reliable and efficient across any situation you build it up to. This (Toyotas) E-CVT is just at home in a RAV4, as it could be… scaled up into a front end loader used on mining sites.
Hi, Thanks for the comment and concern. You should have seen me try to do this demonstration on a steel bench, everything was sticking to the bench and to each other; it was a disaster. I could not even pick up the MG2 rotor when it was on its side. I had to roll it to the edge and slide it off. It is amazing how strong those magnets are. Cool technology!
Key to understanding how the drive works is the fact that MG1 and MG2 are AC motor-generators and their speed can be controlled exactly by the computer. This is how the ratio between crankshaft, electric motors, and drive shaft speed is controlled, i.e., how the drive acts as a CVT.
Thanks for the comparison. I did not know there were any major changes to the transaxle for the 3rd generation prius. This does explain a lot, especially how the plug-in version can go faster in EV mode. I'd like to see an explanation of the Chevy Volt transaxle!
This was a tremendously helpful video and I want to thank the presenter for all the work in doing it. It helped me to understand a lot about planetary gears and sun gears and ring gears and their arrangements. You have to remember what this system is actually doing (and doing very well) in your car. I own a 2016 Prius C, which I love. I suppose the gear ratios in it are even better. As a former operating engineer, I appreciate the genius of Toyota in building these amazing machines. They are only going to get even better. Again, thanks for the great presentation, WeberAuto!
Mechanically, these are very, VERY simple compared to a typical car transmission. All of the complexity is in the electronics and they're proving to be pretty bulletproof.
This was very detailed and helpful, and now I understand how some hybrid vehicles can drive without the engine on at much higher speeds than others. I bought a 2014 Avalon hybrid just a few months ago and I've been so fascinated by the hybrid transmission system. Only regret was not being able to get a newer car with 4th gen transmission, then I could drive without the engine on st much higher speeds
Thanks for helping me to understand how these ecvt transmissions work. The design is so elegant and robust. So much going on with the torque controlling from the ICE and motors. Mind blowing to think about gearing to change maximum e-only vehicle speed. Very cool!
Hi, the motors are three pase AC synchronous (with permanent magnets on the rotor) . They are not induction motors, they are not DC, and they do not use brushes. The ICE is not held stationary, but it stays stationary when off by the engine's own compression, friction, and lack of momentum. It takes much less energy to turn the MG1 motor while in electric mode. The charge rate is turned down to a low level allowing MG1 to rotate with less effort.
My first model Prius 2001; Second Prius 2011. Now I think I understand how the 2011 cruise control is able to slow the car preventing overspeeding on downhill runs, a feature I didn't discover immediately. Very useful function.
Your explanations filled in a lot of the gaps in understanding I had after watching Niels Blaauw's excellent video. These two together cover the topic well.
A reason for the taller gearing on the Prius C is that it runs a lower voltage hybrid battery. Motor RPM is proportional to voltage and so it can't run the motors as fast meaning it needs taller gearing to get the same roadspeed. Given its a smaller, lighter car it needs less torque which is good because that's also what you get with taller ratios :) Great video, thanks.
True on commutator DC motors speed is proportional to voltage but these are actually 3 phase AC motors. (I am pretty sure). The speed will be a function of the frequency output of the drive inverter and the slip speed required to create the required torque. I suspect the Prius C has taller gearing because its a lighter car and is probably more efficient with taller gears
Wow! This is extremely well prepared, well presented, demonstration. I just bought a Prius and, being an engineer, I need to know how it works. This and the simulation that’s available here are definitely clarifying this fascinating system for me. Thanks for all the hard work that obviously went into this. 👍👍👍
Are those actually the motors or just the rotors from the motors ? Either way when you look at the size of a washing machine motor which is only a couple of HP they are incredibly small.
@WeberAuto. Thanks for the video. I was on the fence between getting the 2nd gen & the 3rd gen & now I'm going to pass on the 2nd gen. I also was hesitant on getting a Prius because I thought that it had a belt driven CVT. I feel a lot more comfortable about the decision now. I've also seen high mileage reviews & not one mentioned anything about the transmission or batteries failing.
@@VoiceAlertTexas Oh wow! I've heard that they make very good rebuilt battery kits for around $1,000. I think that beats all the other fails that a regular car could have.
Not really. The Prius is pretty hard to beat. There are thriftier cars to drive but they're almost exclusively tiny, not available in the US, or no longer made - or all of the above.
Very good ! but I have to say, perhaps it is because of this rainy Sunday afternoon, but he threw me in the quickest and deepest sleep I ever experienced in my life...
Great video. I watched an animated video years ago when we bought our 2010 prius. It illustrated the basic concept of how the system worked but left a lot to the imagination as to the actual mechanical setup. For me this video filled in the gap. Good stuff....
Almost no belts or chains. The 1st and 2nd gen had an internal chain link from the output of the planet gears to the differential area of the transaxle. 3rd/4th gen drives the diff directly.
@@alanowa123 thx....now 240000 on it with first battery and i did oil change in the 2 small gear boxes front and rear.. still runs strong ;-) th-cam.com/video/3bSB_TdBA8A/w-d-xo.html
Clutch I think on the 400H might cost thousands, if I don't do it my self. Easy but time consuming. Patience along with all the good info to try swap transfer should be easier specially if I'm not sure what part is wrong like a pin bearing or final drive gear in power split or burnt coils or clutch. Soon as engine comes on its like a broken piston ring bit goes n comes back. Might just be bad gas clogged injector or coil n plugs are toast it looks like. I was driving Ving fast yesterday so I think clutch because it had new oil change. Thanks for the videos top notch
Great video! Watching this because i recently did a hard acceleration onto the freeway with my rav4 hybrid and was worried thinking it had a belt drive cvt.
Weber Inst. Thanks a lot for the videos.. they are very usefull for us, people in the third world where innovations arrive a little late but unfortunely the tecnology for repair it is only for a little groups that prefer to hidden it and be only with the truth. Thanks to you and your org. we can have a better understanding for accomlish the repair labor. In case of electrical vehicles it will be necessary to develop an a very simple way to detect failures with help of a multimeter because other devces are or impossible to get them or innoperable due to lack of escolar education in the electrical area and in the mechanical. thanks once again...
These late versions are much superior to the cone and pulley CVTs which most other cars have. There are no torque converters, gears meshing and un-meshing. None of those wear prone devices. Everything is “tight” at all times. That’s why these transmissions are so reliable.
I have observed and visualised one thing. From 26:38 MG1 is idling in reverse. To run the engine the MG1 field reduces its speed transferring the resisted ring gear motive force to turning the planetary,hence starting the engine which turns in a clockwise direction (in the video the engine is turning in the wrong direction). This confirms the namograph presentations upon running on MG2 and upon MG2 + engine. MG1 changes direction upon the engine running.
Kudzanai MG1 only changes direction with the engine running when the vehicle is stopped, otherwise, it will always rotate the same direction as the engine. Good catch on the entire presentation being shown with the components rotating the opposite direction as they should have been, It makes no difference in the theory of operation though (other than it is backwards). Thanks for watching.
WeberAuto Alright. I had taken it from your P111/P112 presentation, though i now notice MG2 forward has changed owing to the motor speed reduction gearset. You have a wonderful initiative (video lessons).
The IC motor (driving the planetary gear set) must rotate in the opposite direction from the electric motors (both driving sun gears). As the IC motor starts, MG2 must slow down, not speed up. You should re-edit the video to show this, including the IC motor driving the wheels with MG2 stopped.
Thank you for.your explanation was considering purchasing a gen 2 from 2009......but will hold off and purchase a gen 3.....looks like a more efficient and durable design.......
Great explanation. Makes a great piece of engineering understandable One interesting thing is that the IS300h is supposed to have 3rd gen (Lexus info), but since it switches off EV at around 35mph, 40+ if going downhill (if doing just enough power to maintain speed), maybe that doesn't apply to all model years.
My es300h will use just electric even on the freeway if the load is low enough. It can do full electric, the electric motor is 116hp but the battery doesnt have the capacity.
@@CrazyForCooCooPuffs , that's great, it just needs the bigger battery from the Nx450+. If it had that power train and fully foldable seats, it'd be close to perfect. They don't fold to force people to buy SUVs. A real shame
Excellent video! Question: Does an eCVT require any maintenance like fluid changes? If the car is high mileage (e.g. over 300,000km) and the fluid had never been changed, do you recommend to change it or at this point leave it as is? Thanks in advance.
@@WeberAuto Dear Professor Kelly, I have 2 questions please: How is the lubrication implemented? Is it splash lubrication? I see several caged, open deep groove ball bearings and I assume the planet gears use needle bearings. 2) I know Toyota WS (World Standard) ATF is used. How well does the lubrication work at cold temperatures? With the car stationary and the ICE idling high (1300rpm because warm-up), MG1 spins at ~4750rpm. When moving at 50mph, MG2 already spins at ~6000rpm. What if the car sat outside in winter at 5-10°F? Does the lubrication still work reliably? Would it maybe be a good idea to drive a bit slower during the first few miles? I could not find a PID for ATF temperature to monitor how long it takes to warm up. Thank you! Regards Dan
As a neophyte to this design, I was looking for how the vehicle changes gears. Is it correct to say that gears don't need to be changed because the electric motors can operate at widely variable RPM, and the gas engine just helps out by charging the battery, and when needed for a power boost?
Excellent presentation. It looks like planetary gears are becoming the norm on new designs of automatic transaxles (e.g. the 9-gear ZF 9HP, etc.) - perhaps the eCVT is the inspiration or are there other early examples of such planetary gear transmissions in automobile application?
Planetary gear set equipped automatic transmissions have been in mass produced vehicles since 1940. They are great to use because they are compact and can give many different gear ratios. Thanks for your feedback!
Wow, great illustration of hybrid synergy drive. I have the Prius Plugin. Now I understand how this works,it gives me a piece of mind that it will last for a long long time! With this explanation, I can see why the Prius Prime evolved the same pathway to even higher electric only speed with the same concept. No wonder it is so reliable. By evolution road proven approach, you have real life test runs already done instead of revolutionary method that needs to be take a good time proven initially to get it right.
Thanks for the feedback. Here is a new series on all four generations of Toyota hybrid transaxles. th-cam.com/play/PLIn3FrDiB1lyzmzZNBM24V_FsyuDx8ow_.html Have a good day!
Great video as usual. I was a bit scared for your fingers there at times.... might want to move this to a flat solid steel bench in the future. Sfety first ;-)
So, just two main changes, aside from various sizing changes: 1- unitized, clutch assembly (non-serviceable friction plate) 2-dual plane planetary, with independent ratios for MG1/MG2 Did I miss anything?
Thanks for those great videos about hybrid system .please sir can you tell me which video I should start I want to know everything about hybrid God bless you sir
In reference to ToyotaKTM, possibly Toyota Engineering wanted to use a starter motor on the original ICE. So, they ordered the ring gear on the flywheel. Then, at some later point, the starter was eliminated. The other theory could be that this flywheel is a multi-purpose flywheel that can be used in another vehicle, not propriety to Prius. I saw the ring gear on the flywheel and questioned the same thing.
Thanks for the very informative video! I have a couple questions if you don't mind... What kind of motors are MG1 and MG2? DC brushless? Also, what holds the ICE stationary when in pure electric mode? Is there some sort of brake band?
Thanks for this great video. This makes many things clear! I think you made a mistake in the description of the transition of MG2 drive to ICE drive (27:00): You turn the ICE clutch damper in the wrong direction so that MG1 will turn faster (obviously too fast if it´s already a bit quicker than MG2). Actually MG1 will turn slower (breaking as a generator) to start moving the ICE in the SAME direction as the wheelgear already rotates. At eahart.com/prius/psd/ this is well demonstrated with the shown nomograph. Moreover at higher speeds there is a point where MG1 stops spinning and reverses direction. Remarkable difference to 2nd generation PSD: In normal forward drive the ICE and MG2 rotate in reverse directions! This is caused by the additional planetary gear set in gen. 3.
Yes, when the vehicle is in good forward motion and the Internal Combustion Engine (ICE) is to be started, the rotational speed of MG1 is decreased by applying a breaking force by means of electric current to MG1 from an electric converter. At low forward (or reverse) motion of the vehicle, or high rotational speed (RPM) of the ICE, MG1 reverses rotational direction. In 4th. generation Prius, MG2 is no longer coaxial with MG1 and the ICE. I'm unsure as to whether MG2 employs a planetary gear set or not in 4th. generation Prius.
good work Weber, this is hard information to find. I watched your whole video at regular speed and found it informative but i wish you'd work on your presentation a bit better as i didn't think to use 2x speed.
+Lakshmanan Palaniappan Hi, it is very similar to the Pruis transaxle except is has some clutch packs to prevent their MG1 from overspeed problems. The Volt also has a clutch pack to connect and disconnect the engine from the transaxle. Thanks for watching!
This is a masterpiece of engineering!! It’s the culmination of the CVT principle, without the friction issues of a CVT, in a smaller/lighter package than any other transmission, incorporating hybrid electrical drive/generation systems, into an extremely reliable transmission… which is scalable, reliable and efficient across any situation you build it up to.
This (Toyotas) E-CVT is just at home in a RAV4, as it could be… scaled up into a front end loader used on mining sites.
I'm super amazed to see that 1.2 MILLION people expressed interest in learning about these transmission from your video 😳
These are literally the most reliable transmission systems in the world right now, and you can see why.
I wonder how much less reliable 2nd Gen are compared to the 3rd Gen.
@@MaximC They aren’t less reliable.
@@afcgeo882
You sure? I've read the chain may fail. Why they changed it to direct then, for other reasons?
@@MaximC It has NO chain! Did you watch the video? Toyota’s eCVT are planetary gear sets, not CVTs.
@@afcgeo882
He did mention it, a chain in 1st and 2nd generation of Toyota's PSD/eCVT.
Hi, Thanks for the comment and concern. You should have seen me try to do this demonstration on a steel bench, everything was sticking to the bench and to each other; it was a disaster. I could not even pick up the MG2 rotor when it was on its side. I had to roll it to the edge and slide it off. It is amazing how strong those magnets are. Cool technology!
Key to understanding how the drive works is the fact that MG1 and MG2 are AC motor-generators and their speed can be controlled exactly by the computer. This is how the ratio between crankshaft, electric motors, and drive shaft speed is controlled, i.e., how the drive acts as a CVT.
Great feedback!
Great explanation
@@WeberAuto does the lexus gs450h hybrid gearbox have the same mechanism and work in the same manor?
Thanks for the comparison. I did not know there were any major changes to the transaxle for the 3rd generation prius. This does explain a lot, especially how the plug-in version can go faster in EV mode. I'd like to see an explanation of the Chevy Volt transaxle!
Wow, you commented this way before you made it big.
Hi!
wow
I love this eCVT on my Sienna! There's basically no lag in acceleration at any speed!
This was a tremendously helpful video and I want to thank the presenter for all the work in doing it. It helped me to understand a lot about planetary gears and sun gears and ring gears and their arrangements. You have to remember what this system is actually doing (and doing very well) in your car.
I own a 2016 Prius C, which I love. I suppose the gear ratios in it are even better. As a former operating engineer, I appreciate the genius of Toyota in building these amazing machines. They are only going to get even better.
Again, thanks for the great presentation, WeberAuto!
Thank you!
Watch these videos all the time this guy is a transmission PRO!!!
Great explanation! I can’t believe how small it all is and that there is no cvt belt. It’s nice to understand my car more.
Mechanically, these are very, VERY simple compared to a typical car transmission. All of the complexity is in the electronics and they're proving to be pretty bulletproof.
This was very detailed and helpful, and now I understand how some hybrid vehicles can drive without the engine on at much higher speeds than others.
I bought a 2014 Avalon hybrid just a few months ago and I've been so fascinated by the hybrid transmission system. Only regret was not being able to get a newer car with 4th gen transmission, then I could drive without the engine on st much higher speeds
Nice to see this graphically illustrated. Thank you.
Thank you!
Thanks for helping me to understand how these ecvt transmissions work. The design is so elegant and robust. So much going on with the torque controlling from the ICE and motors. Mind blowing to think about gearing to change maximum e-only vehicle speed. Very cool!
Hi, providing various amounts of resistance causes the overall gear ratio vary. It makes the transmission act like a CVT.
Hi, the motors are three pase AC synchronous (with permanent magnets on the rotor) . They are not induction motors, they are not DC, and they do not use brushes. The ICE is not held stationary, but it stays stationary when off by the engine's own compression, friction, and lack of momentum. It takes much less energy to turn the MG1 motor while in electric mode. The charge rate is turned down to a low level allowing MG1 to rotate with less effort.
My first model Prius 2001; Second Prius 2011. Now I think I understand how the 2011 cruise control is able to slow the car preventing overspeeding on downhill runs, a feature I didn't discover immediately. Very useful function.
Your explanations filled in a lot of the gaps in understanding I had after watching Niels Blaauw's excellent video. These two together cover the topic well.
A reason for the taller gearing on the Prius C is that it runs a lower voltage hybrid battery. Motor RPM is proportional to voltage and so it can't run the motors as fast meaning it needs taller gearing to get the same roadspeed. Given its a smaller, lighter car it needs less torque which is good because that's also what you get with taller ratios :)
Great video, thanks.
True on commutator DC motors speed is proportional to voltage but these are actually 3 phase AC motors. (I am pretty sure). The speed will be a function of the frequency output of the drive inverter and the slip speed required to create the required torque. I suspect the Prius C has taller gearing because its a lighter car and is probably more efficient with taller gears
Wow! This is extremely well prepared, well presented, demonstration. I just bought a Prius and, being an engineer, I need to know how it works. This and the simulation that’s available here are definitely clarifying this fascinating system for me. Thanks for all the hard work that obviously went into this. 👍👍👍
Thank you!
Excellent - thank you! Those gear sets are works of art. Amazing to see how compact the electric motors are compared to an internal combustion engine.
Hm
Hm
Are those actually the motors or just the rotors from the motors ?
Either way when you look at the size of a washing machine motor which is only a couple of HP they are incredibly small.
Yes likely just the rotors shown there. Would be nice to see the entire assembly.
Excellent explanation of the gen 3 gear set in the transaxle
Thank you!
Great breakdown of the e-CVT!
@WeberAuto. Thanks for the video. I was on the fence between getting the 2nd gen & the 3rd gen & now I'm going to pass on the 2nd gen. I also was hesitant on getting a Prius because I thought that it had a belt driven CVT. I feel a lot more comfortable about the decision now. I've also seen high mileage reviews & not one mentioned anything about the transmission or batteries failing.
Thanks, The 3rd gen is a great car
Batteries shot after 200,00 for sure.. I know.....I have a 2013 with 206,000
@@VoiceAlertTexas Oh wow! I've heard that they make very good rebuilt battery kits for around $1,000. I think that beats all the other fails that a regular car could have.
@Paul Stejskal No it can't, the whole point is the batteries powering the vehicle half of the time, it is more an electric vehicle with ICE assist.
07 Camry, 380000 miles, original battery still going
If people knew how insane geniously this is and work, everyone would buy toyota hybrid. It works just amazingly great.
its neat but if fuel economy is your game there might be better choices.
Not really. The Prius is pretty hard to beat. There are thriftier cars to drive but they're almost exclusively tiny, not available in the US, or no longer made - or all of the above.
either way, they are a bit "optimistic" with their mileage ratings.
My wife's 2010 gets 50 mpg +/- 3 mpg all year long, even though most of her driving is short trips.
My wife still gets the rated 47 MPG in her 2008 with 160,000 miles on it.
Very good ! but I have to say, perhaps it is because of this rainy Sunday afternoon, but he threw me in the quickest and deepest sleep I ever experienced in my life...
The third generation is a better output flow with less rotational speed of MG1 and much more torque overall. Very good description!
Great video. I watched an animated video years ago when we bought our 2010 prius. It illustrated the basic concept of how the system worked but left a lot to the imagination as to the actual mechanical setup. For me this video filled in the gap. Good stuff....
Glad to hear. Thanks for watching
Love these Hybrid transaxle videos
Thank you
This was absolutely fascinating
Thank you
That was so relaxing to watch for some reason. Oh, and really informative. We have a 3rd gen Prius and 3rd gen Highlander hybrid. Thx!
Excellent piece of engineering.
Hi, the design is more compact, lightweight, and allows for increased torque through the gear reduction with a lighter-smaller motor.
So, no chain, no belt, all geared.
This should be more durable than the CVT in the background that's belt driven.
Very true!
Almost no belts or chains. The 1st and 2nd gen had an internal chain link from the output of the planet gears to the differential area of the transaxle. 3rd/4th gen drives the diff directly.
@@Driver6M what does my RX450h from 2010/11 have ?
@@kubanskiloewe only gears, no moving parts expect gears
@@alanowa123 thx....now 240000 on it with first battery and i did oil change in the 2 small gear boxes front and rear.. still runs strong ;-) th-cam.com/video/3bSB_TdBA8A/w-d-xo.html
Very nice way of demonstration , easy to understand the functions..... thank you so much.......
Thank you!
Weber' your are only one i can get this information.. its is very important you to train or teach your knowledge to more people..
Ingenious design...great presentation!
Please keep making videos, very helpful and educational. Thank you!
Thank you!
Clutch I think on the 400H might cost thousands, if I don't do it my self. Easy but time consuming. Patience along with all the good info to try swap transfer should be easier specially if I'm not sure what part is wrong like a pin bearing or final drive gear in power split or burnt coils or clutch. Soon as engine comes on its like a broken piston ring bit goes n comes back. Might just be bad gas clogged injector or coil n plugs are toast it looks like. I was driving Ving fast yesterday so I think clutch because it had new oil change. Thanks for the videos top notch
"Very strong magnets" *sticks hand between them.
感恩了解，謝謝分享！
very good explanation. that was a very good demo. I haven't a clue how it works. very good for Prius owners.
justin sincoise Thank you!
Thank you John Kelly and Weber State University - a first class explanation.
Thank you!
Great video. Nothing that can fail here. Compare to Hyundai ioniq hybrid where many things can fail.
Great video! Watching this because i recently did a hard acceleration onto the freeway with my rav4 hybrid and was worried thinking it had a belt drive cvt.
Glad it helped! Thanks for watching
whats the problem of your rav4? i have same issues
OUTSTANDING! BRAVO! CAPITAL!
Thank you!
Very concise explanation
Great video! One item to note: at 26:09, you were pointing to MG2, but you said MG1.
Good catch, you are correct.
Weber Inst. Thanks a lot for the videos.. they are very usefull for us, people in the third world where innovations arrive a little late but unfortunely the tecnology for repair it is only for a little groups that prefer to hidden it and be only with the truth. Thanks to you and your org. we can have a better understanding for accomlish the repair labor.
In case of electrical vehicles it will be necessary to develop an a very simple way to detect failures with help of a multimeter because other devces are or impossible to get them or innoperable due to lack of escolar education in the electrical area and in the mechanical. thanks once again...
Thank you for your teaching. 👋👋👋💜🌈🙏 I love Toyota 💖
Absolutely great video! I've got P314 in my Toyota Harrier 2015. This helps a lot to understand what is going on under the hood! Huge thanks!
Very nice explanation. And a very reliable design compared to automatic and cvt transmissions.
Great video. Excellent explanation.
Thank you!
Great explanation, excellent information to understand how to work the e-cvt transmission. Congratulations!!
you did a very good presentation! thank you!
Thank you!
EXCELLENT videos thanks a lot for taking the time to make them
very appreciated for this explanation. I like it.
Thanks for all your awesome videos!
Nice presentation.
Thank you!
These late versions are much superior to the cone and pulley CVTs which most other cars have. There are no torque converters, gears meshing and un-meshing. None of those wear prone devices. Everything is “tight” at all times. That’s why these transmissions are so reliable.
Awesome video!
Thanks Professor Kelly. Regards, Ramish.
Thank you!
I have observed and visualised one thing. From 26:38 MG1 is idling in reverse. To run the engine the MG1 field reduces its speed transferring the resisted ring gear motive force to turning the planetary,hence starting the engine which turns in a clockwise direction (in the video the engine is turning in the wrong direction). This confirms the namograph presentations upon running on MG2 and upon MG2 + engine. MG1 changes direction upon the engine running.
Kudzanai MG1 only changes direction with the engine running when the vehicle is stopped, otherwise, it will always rotate the same direction as the engine. Good catch on the entire presentation being shown with the components rotating the opposite direction as they should have been, It makes no difference in the theory of operation though (other than it is backwards). Thanks for watching.
WeberAuto Alright. I had taken it from your P111/P112 presentation, though i now notice MG2 forward has changed owing to the motor speed reduction gearset. You have a wonderful initiative (video lessons).
The IC motor (driving the planetary gear set) must rotate in the opposite direction from the electric motors (both driving sun gears). As the IC motor starts, MG2 must slow down, not speed up. You should re-edit the video to show this, including the IC motor driving the wheels with MG2 stopped.
Thank you for.your explanation was considering purchasing a gen 2 from 2009......but will hold off and purchase a gen 3.....looks like a more efficient and durable design.......
I agree, Thanks for your feedback
Thanks a lot for this great Video, very, very illustrative.. Them no dudes !!
Thank you!
Best videos! I understand the prius transaxle better. Thanks.
Thank you so much for your video
Genius mechanism
Thank you professor.
Great explanation. Makes a great piece of engineering understandable
One interesting thing is that the IS300h is supposed to have 3rd gen (Lexus info), but since it switches off EV at around 35mph, 40+ if going downhill (if doing just enough power to maintain speed), maybe that doesn't apply to all model years.
My es300h will use just electric even on the freeway if the load is low enough. It can do full electric, the electric motor is 116hp but the battery doesnt have the capacity.
@@CrazyForCooCooPuffs , that's great, it just needs the bigger battery from the Nx450+. If it had that power train and fully foldable seats, it'd be close to perfect. They don't fold to force people to buy SUVs. A real shame
Excellent video! Question: Does an eCVT require any maintenance like fluid changes? If the car is high mileage (e.g. over 300,000km) and the fluid had never been changed, do you recommend to change it or at this point leave it as is? Thanks in advance.
Yes, every 193,000 km, change the fluid with Toyota WS fluid. Best wishes!
WeberAuto Is it safe to do even though it’s never been changed after clocking a high number of miles?
Thank you for doing this video. Great info!
great explination well done job
Thank you
Keep doing a job u seems to enjoy
u are welcome sir
@@WeberAuto
Dear Professor Kelly, I have 2 questions please:
How is the lubrication implemented? Is it splash lubrication? I see several caged, open deep groove ball bearings and I assume the planet gears use needle bearings.
2) I know Toyota WS (World Standard) ATF is used. How well does the lubrication work at cold temperatures? With the car stationary and the ICE idling high (1300rpm because warm-up), MG1 spins at ~4750rpm. When moving at 50mph, MG2 already spins at ~6000rpm. What if the car sat outside in winter at 5-10°F? Does the lubrication still work reliably? Would it maybe be a good idea to drive a bit slower during the first few miles?
I could not find a PID for ATF temperature to monitor how long it takes to warm up.
Thank you!
Regards
Dan
Thanks for the video! I love my Gen II and my C. Amazing feats of engineering IMO.
As a neophyte to this design, I was looking for how the vehicle changes gears. Is it correct to say that gears don't need to be changed because the electric motors can operate at widely variable RPM, and the gas engine just helps out by charging the battery, and when needed for a power boost?
Great review, thanks.
Thanks for the education! That is quite the mechanism! Enlightening even to a neophyte like me.
Awesome! Thankyou!
Thank you!
Great video !! Thanks
THANK YOU JOHN.HAVE A NİCE DAY
Thank you!
excellent!!!! greetings from mexico!!!
Excellent presentation. It looks like planetary gears are becoming the norm on new designs of automatic transaxles (e.g. the 9-gear ZF 9HP, etc.) - perhaps the eCVT is the inspiration or are there other early examples of such planetary gear transmissions in automobile application?
Planetary gear set equipped automatic transmissions have been in mass produced vehicles since 1940. They are great to use because they are compact and can give many different gear ratios. Thanks for your feedback!
Wow, great illustration of hybrid synergy drive. I have the Prius Plugin. Now I understand how this works,it gives me a piece of mind that it will last for a long long time! With this explanation, I can see why the Prius Prime evolved the same pathway to even higher electric only speed with the same concept. No wonder it is so reliable. By evolution road proven approach, you have real life test runs already done instead of revolutionary method that needs to be take a good time proven initially to get it right.
Thanks for the feedback. Here is a new series on all four generations of Toyota hybrid transaxles. th-cam.com/play/PLIn3FrDiB1lyzmzZNBM24V_FsyuDx8ow_.html Have a good day!
Brilliant video! Loved it very informative
Great video as usual. I was a bit scared for your fingers there at times.... might want to move this to a flat solid steel bench in the future. Sfety first ;-)
You seem very excited about what you do
Thank you! Yes, I love my job!
Great video, thank you!
So, just two main changes, aside from various sizing changes:
1- unitized, clutch assembly (non-serviceable friction plate)
2-dual plane planetary, with independent ratios for MG1/MG2
Did I miss anything?
good video. thanks. excellent video
Thanks for those great videos about hybrid system .please sir can you tell me which video I should start I want to know everything about hybrid God bless you sir
Hi this is a great video, one thing I’m curious about is what happens when you over speed the motors, such as what harm does it do?
You risk beating failure from overheating and inadequate lubrication
Great explanation.
good description
In reference to ToyotaKTM, possibly Toyota Engineering wanted to use a starter motor on the original ICE. So, they ordered the ring gear on the flywheel. Then, at some later point, the starter was eliminated. The other theory could be that this flywheel is a multi-purpose flywheel that can be used in another vehicle, not propriety to Prius. I saw the ring gear on the flywheel and questioned the same thing.
Thanks for the very informative video!
I have a couple questions if you don't mind... What kind of motors are MG1 and MG2? DC brushless? Also, what holds the ICE stationary when in pure electric mode? Is there some sort of brake band?
Thanks for this great video. This makes many things clear!
I think you made a mistake in the description of the transition of MG2 drive to ICE drive (27:00): You turn the ICE clutch damper in the wrong direction so that MG1 will turn faster (obviously too fast if it´s already a bit quicker than MG2). Actually MG1 will turn slower (breaking as a generator) to start moving the ICE in the SAME direction as the wheelgear already rotates. At eahart.com/prius/psd/ this is well demonstrated with the shown nomograph. Moreover at higher speeds there is a point where MG1 stops spinning and reverses direction.
Remarkable difference to 2nd generation PSD: In normal forward drive the ICE and MG2 rotate in reverse directions! This is caused by the additional planetary gear set in gen. 3.
seriously ! chump
Yes, when the vehicle is in good forward motion and the Internal Combustion Engine (ICE) is to be started, the rotational speed of MG1 is decreased by applying a breaking force by means of electric current to MG1 from an electric converter. At low forward (or reverse) motion of the vehicle, or high rotational speed (RPM) of the ICE, MG1 reverses rotational direction. In 4th. generation Prius, MG2 is no longer coaxial with MG1 and the ICE. I'm unsure as to whether MG2 employs a planetary gear set or not in 4th. generation Prius.
good work Weber, this is hard information to find. I watched your whole video at regular speed and found it informative but i wish you'd work on your presentation a bit better as i didn't think to use 2x speed.
Thanks for watching!
Hi ! Thanks for the in depth explanation....Can you explain the chevy volt hybrid transmisson?..it looks quite different than the Prius system
+Lakshmanan Palaniappan Hi, it is very similar to the Pruis transaxle except is has some clutch packs to prevent their MG1 from overspeed problems. The Volt also has a clutch pack to connect and disconnect the engine from the transaxle. Thanks for watching!
Thank you very much!
You're welcome!
priceless video. Thanks a lot