Fuji, Shizuoka – JATCO Ltd has developed a new continuously variable transmission (CVT) for medium to large FWD vehicles that brings a leap in environmental performance and drivability, the “Jatco CVT-X” (JF022E) (hereinafter CVT-X).
Ever since JATCO succeeded in the mass production of the F06A (the world’s first metal-belt CVT for 2-liter-class engines) in 1997, we have produced over 50 million CVTs as a CVT pioneer. The CVT-X is the result of us challenging the utmost limits as a transmission manufacturer to realize a leap in environmental performance and drivability. Moreover, we have overcome the 90% transmission efficiency barrier, a feat considered very difficult for CVTs, and reached a higher level of perfection than ever before. The letter “X” in the name CVT-X reflects this with its meanings of “ultimate,” “challenging the unknown,” and “unlimited possibilities.”
The main features of the CVT-X
- Ideal CVT for even turbocharged engines
Downsized turbocharged engines provide good fuel economy while suppressing CO2 emissions. The CVT-X can be paired perfectly with these engines, actively utilizing the high-efficiency region of the engine while providing responsive oil pressure and torque converter lock-up that instantaneously tracks the torque when turbo boosting.
- Exhaustive friction reduction
We reduced friction by roughly 30% compared to our existing CVT in the same class, the Jatco CVT8, by thoroughly re-examining areas of mechanical friction, such as oil pumps, seal rings, and bearings. In addition, by using a chain pitch 10% shorter than existing models, the newly adopted chain for the gear-shifting mechanism can be used with smaller diameters, achieving a ratio coverage of 8.2. This allows us to run the engine at lower RPMs when in high-speed cruise. Moreover, we re-examined the torque converter’s lock-up mechanism, and by expanding the slip lock-up region, we improved fuel economy by 8% compared to the Jatco CVT8.
- Superior drivability
The CVT-X has excellent acceleration performance from rest due to the 8.2 ratio coverage enabled by using a short-pitch chain and the greatly reduced time to lock-up completion enabled by the use of a multi-plate lock-up mechanism for the torque converter. Moreover, by combining feed-forward and feedback control, we were able to reduce both shift response time and shift shock, utterly minimizing the time between accelerator input and vehicle response, allowing the driver to drive exactly as they please.
- Excellent noise, vibration, and harshness (NVH) performance
By using a random pitch chain with both short and traditional pitch lengths for the pin spacing and a new, highly-rigid chain guide configuration, we keep chain vibrations under control. With this, we can deliver a quiet and comfortable ride, even with a chain-type CVT.
The CVT-X is installed in the Nissan Qashqai, on sale in Europe since June 2021.
About JATCO Ltd
Headquartered in Fuji, Shizuoka, JATCO is a leading automotive transmission manufacturer, specializing in the design, development, and manufacture of automatic transmissions and CVTs. In addition to plants in Japan, JATCO has production facilities in Mexico, China, and Thailand.