In late February 2018, Toyota revealed a whole range of new technologies that will be used in future vehicles based on the Toyota New Global Architecture (TNGA). One of those technologies is the Direct Shift-CVT, which features a launch gear to increase the efficiency of the belt-driven system.
To better understand how it works, Jason Fenske from Engineering Explained has uploaded a video to explain the purpose of the launch gear, and how it improves the CVT.
In Toyota’s new transmission, the CVT switches to the launch gear when setting off from a stop. This provides direct gear drive, much like starting in first gear in a manual transmission. However, as the vehicle speeds up, the launch gear is dropped and the transmission switches to belt drive and operates like a regular CVT.
The launch gear results in better acceleration when setting off, and helps deal with the “sluggishness” that people find when driving a CVT. With the launch gear taking over accelerating duties from a standstill, Toyota has also been able to fit smaller belt and pulley components, along with a narrower belt angle (9 degrees from 11 degrees), result in shifting speeds that are 20% faster.
