Can a CVT Boost EV Performance?
Bosch says new gearbox can better balance efficiency and peak output
Share
Bosch is developing a continuously variable transmission (CVT) system specifically for electric vehicles, which typically use single-speed units.
How It Works
(Images: Bosch)
The aptly named CVT4EV is teamed with an inverter, electric motor and a final drive ratio tuned to the vehicle application.
Using machine learning, the system takes into account vehicle speed, energy consumption and heat production to optimize the drive ratios of the CVT so the motor can operate at its most efficient point, according to the supplier.
What’s the Advantage?
By controlling the speed and torque of the electric motor, Bosch says the system is able to provide:
- Faster acceleration
- Higher top speeds
- Greater wheel torque for towing and off-road driving
There also are fewer torque and rpm restrictions. This enhances shift smoothness and overall NVH.
Smaller Size or Longer Range
CVT4EV’s lower torque and speed requirements can enable a smaller electric motor to be used.
Or, Bosch notes, OEMs could opt to extend driving range by using the same size motor as current EVs.
Flexibility
To further reduce costs, the scalable design can be used for various EVs, ranging from small and midsize cars to performance models and light commercial vehicle.
At the same time, the supplier says, carmakers can tune the system for multiple driving modes (uphill, off-road, normal) and brand-specific characteristics.
Dutch Connection
The CVT4EV concept was developed by Bosch’s Transmission Technology unit in the Netherlands.
What’s Next?
Bosch says it can adapt many existing components for use in the CVT4EV, and now is working with transmission companies to build prototype models.
The supplier also is in talks with multiple OEMs about the program. No commercialization timeline was provided.
RELATED CONTENT
-
When Automated Production Turning is the Low-Cost Option
For the right parts, or families of parts, an automated CNC turning cell is simply the least expensive way to produce high-quality parts. Here’s why.
-
Global Supply of Automotive Fasteners from a Single Source
PennEngineering offers a global supply for a wide range of fasteners for the automotive industry, including China-based facilities that manufacture standard and custom products to world-class standards of quality at lower cost.
-
The Lexus GX 470: You Want Me To Drive This Where?
According to Kunihiro Hoshi, chief engineer for the GX 470: “Three of my top goals were to create a body-on-frame vehicle with sweeping off-road performance and unibody-like on-road capability, and, of course, it had to meet the Lexus quality standard.” He met his goals. But why would anyone want to bang this vehicle around on rocks?
