Once You Understand it, You Will Think Everything Else is Silly - Toyota E-CVT

Support the channel by shopping through this link: https://amzn.to/4fatbMb Become a member:    / @d4a   Patreon:   / d4a   This is a Toyota E-CVT used in pretty much all Toyota hybrid and plug-in hybrid vehicles. It is a transmission that has an infinite number of speeds while at the same time being more compact and lightweight than any conventional transmission. It has virtually no wear parts, it never shifts and it has bulletproof reliability. The number of moving parts on my model is almost the same as in any actual Toyota hybrid car and is dramatically lower than the number of moving parts inside any conventional transmission. This car has no shift forks, no clutches or clutch packs, no pulley, no belts, no chains, no sleeves, no synchros, no valve bodies, no torque converters. No nothing. It’s literally just a bunch of gears. The only catch is that this transmission can only be operated by a hybrid, and that’s because it needs two inputs, an internal combustion engine alone cannot run this. At the heart of the transmission, we have this which is a planetary gear set aka power split device. It’s called a planetary gear set because the central green gear is sort of like the sun, the red gears are like planets because they rotate around it and the outer blue part is called the ring gear. On this side we have the motor generator 1 and motor generator 2. Motor generator 1 is connected to the sun gear. Motor generator 2 is connected to the ring gear. Now, both MG1 and MG2 are three phase AC permanent magnet motors which means that they can act both as a motor, in which case they turn electrical energy into motion or torque and they can do this in both directions, OR they can act as generators in which case they turn motion into electricity; this too they can do in both directions of rotation. On the other side we have the internal combustion engine which is as you can see connected to the planet gears. So let’s start in EV only mode. In this mode there is only one thing happening and that is that MG2 is consuming electricity stored in the battery in order to turn the the wheels, via the ring gear, that’s it. The engine is doing nothing, 0 rpm turned off. The planets gears simply freewheel on their shafts without any rotation of the engine itself. Ok now let’s imagine we are merging onto the highway and the EV mode alone is no longer able to provide sufficient power to attain highway speeds. In that case the engine starts and joins the party which means that we are now in hybrid mode. The first question we must ask is how does the engine even start? Because all Toyota and other hybrid vehicles using this anatomy have no starter motor. The duty of starting the engine is handled by MG1, which being a big three-phase AC motor is an extremely robust and reliable engine starting solution. But it’s not just reliable, it can spin up the engine to any required RPM, which builds the required oil pressure and then the ECU just fires the spark plugs and injects the fuel to start combustion at that particular RPM. At the same time the anatomy of the planetary gearset means that engine torque doesn’t just abruptly jump in like in other hybrid systems which are basically just electrified conventional automatics. In an e-cvt the engine torque is smoothly blended into the drivetrain. You will never actually feel the engine come on, you will only hear it. There is no jolt or drivetrain shock of any kind. But here’s the real magic. As we said this is a CVT. So let’s imagine that what my hand is doing right now is something like 2500 rpm, or peak efficiency RPM for the engine. Wheel speed will keep increasing while engine rpm will remain the same. This is the beauty of a planetary gearset. By changing the speed and direction of MG1 we can continuously and infinitely vary the gear ratio to change the wheel speed while engine rpm remains perfectly constant. The only downside is a disconnection between engine rpm and vehicle speed which feels strange to most people, leading to a somehwat boring and indirect driving experience. So, it's not fun but it is extremely well-engineered. A special thank you to my patrons: Daniel Peter Della Flora valqk Dave Westwood Zwoa Meda Beda Cole Philips Allan Mackay Sam Lutfi Alex 00:00 The Problem With Geared Manuals and Automatics 03:14 The Problem With CVTs 05:36 Toyota E-CVT - The Solution to Both Problems 08:16 EV only mode 09:15 Smooth Torque Blending in Hybrid mode (parallel) 10:40 Changing Vehicle Speed Without Changing Engine RPM 11:54 Engine as Battery Charger 12:32 Wheels as Battery Charger (Regen Braking) 13:18 Reversing 13:41 Overview of 4 E-CVT Propulsion modes 15:02 Advanced Class - EV Speed Limit Why? 16:31 Preventing Reverse Engine Rotation on Toyota E-CVT PHEVs 17:26 Fake Neutral 18:22 What does B do? 19:34 Quiz Question 20:39 Electrical Cost of Changing the Gear Raatio 22:22 Why is it Boring? #d4a #ecvt #toyota