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I am having a bit of a debate with a buddy of mine that claims that the internal combustion engine in the RAV4 is directly connected to the axles and thus directly powers the wheels. Based on my reading, however, it seems that the engine is connected to MG1 (generator) that then powers MG2 (electric drive motor).

So which is it exactly and, is there any collateral to confirm one or the other?
 

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I am having a bit of a debate with a buddy of mine that claims that the internal combustion engine in the RAV4 is directly connected to the axles and thus directly powers the wheels. Based on my reading, however, it seems that the engine is connected to MG1 (generator) that then powers MG2 (electric drive motor).

So which is it exactly and, is there any collateral to confirm one or the other?
This video (
) shows you how the Toyota Hybrid system works on the Prius which is nearly identical to how it works on the Rav4 Hybrid. The way i understand it MG2 turns at the same RPM as the wheel drive, and the power split device is able to basically combine MG2 and Engine Torque to flow to the wheels.
 

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I am having a bit of a debate with a buddy of mine that claims that the internal combustion engine in the RAV4 is directly connected to the axles and thus directly powers the wheels. Based on my reading, however, it seems that the engine is connected to MG1 (generator) that then powers MG2 (electric drive motor).

So which is it exactly and, is there any collateral to confirm one or the other?
Either or Both...Through the eCVT.
 

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The drivetrain uses the motor generator's magnets and coils as a clutch so even though the engine does not physically connect to the drivetrain it directly powers it through magnetic force if that makes any sense. This allows it to more directly drive energy to the drivetrain without converting to elecricity and back, which is lossy.
 

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My monroney window sticker says I have an electronically controlled variable ratio transmission. What is the eCVT if it’s not a transmission? Maybe I’m misinformed.
 

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My monroney window sticker says I have an electronically controlled variable ratio transmission. What is the eCVT if it’s not a transmission? Maybe I’m misinformed.
The short video that somewhat explains it is here:
The long video that fully explains it is here (Applicable to Rav4 system as well even if actual part numbers differ):

Short story Engine, Electric Motor (MG2) and Electric Generator (MG1) are all connected to a 3 way mechanical power splitter called the power split device. Thus depending on Engine RPM, MG2 RPM and Rotation direction and MG1 RPM and Rotation direction the system can generate near infinite "Gears". Thats where the "e" comes from in the "eCVT", its all electronically controlled using Engine RMP, MG1 RPM and Rotation Direction, and MG2 RPM and Rotation direction. Its quite complex and is explained in the long video above.
 

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My monroney window sticker says I have an electronically controlled variable ratio transmission. What is the eCVT if it’s not a transmission? Maybe I’m misinformed.
The main electric motor acts as a huge clutch and sends power to the wheels, to the battery, and sometimes uses the electric motor to add extra power to the battery in addition to the engine based on what the computer thinks the car needs. There is no band or gears that change like a cvt or traditional transmission. There is a planetary gearset involved that allows the system to work, which is one of toyotas main patents if I understand correctly.

The video explains it better than I. 🙂
 

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Discussion Starter #13
Thanks all - so based on the toyota hybrid system video, it looks like the crankshaft connects directly to the power split device and thus the variable power source flow.
 

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Pretty much the same except the RAV4 hybrid has a standalone electric motor in the
rear.

 

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My monroney window sticker says I have an electronically controlled variable ratio transmission. What is the eCVT if it’s not a transmission? Maybe I’m misinformed.
I do think that the origin of the term transmission is that it transmits power from the ICE to the wheels. So the eCVT does do that. A conventional transmission changes gear ratios in the process and people have come to think of a transmission as a device that changes gears which the eCVT does not.

So, call it what you want but try to understand the brilliance of the design.
 
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