Toyota Hybrid Transmission Operation - 15 Years on YouTube!

Join me as I redo a demonstration of the Toyota Hybrid System (THS) transmission operation I produced fifteen years ago. Explore the components involved and their functions. TIMELINE: 0:00 Introduction 0:18 The internal combustion engine (ICE) crankshaft 0:37 Flywheel and torque-damping/limiting clutch 1:12 The planet carrier, gears, and shaft 1:42 The sun gear and motor/generator one 2:55 The ring gear and motor/generator two 3:25 The completed assembly of parts 3:40 The functions of motor/generator two (MG2) 3:50 The functions of motor/generator one (MG1) 4:01 MG1 starting the ICE 4:28 MG1 as a generator for the high-voltage (HV) battery 4:44 The ICE and MG1 combine to provide variable gear ratios from the crankshaft to the wheels. 5:13 Direct drive 1:1 gear ratio 5:42 Underdrive (greater than a 1:1 gear ratio) for acceleration 6:25 Overdrive (less than a 1:1 gear ratio) for higher vehicle speeds 7:52 Electronic Continuously Variable (eCVT) 8:15 Electric vehicle mode - Forward movement 8:48 Electric vehicle mode - Reverse movement 8:55 Series-Parallel transmission in Series Mode 9:38 Series-Parallel transmission in Parallel Mode 10:35 Regerative Braking 10:57 My 2010 YouTube video on this topic has a few errors, so I decided to reshoot it for its 15th anniversary. ABOUT US Weber State University (WSU) Davis Campus - Automotive Technology Department - Hybrid and Electric Vehicles Lab. We teach current vehicle technologies to our automotive students at Weber State University and online. For more information, visit: https://www.weber.edu/automotive This video was created and edited by Professor John D. Kelly at WSU. For a full biography, see https://www.weber.edu/automotive/J_Kelly.html ADDITIONAL TRAINING FOR YOU Join us for hybrid and electric vehicle training with two online courses and a 5-day on-campus boot camp with Professor John D. Kelly. See https://www.weber.edu/evtraining DONATE TO OUR DEPARTMENT Please consider a donation in my name to the Department of Automotive Technology at Weber State University here: https://advancement.weber.edu/Automotive

Added 15 Jun 2026