Development of the Ball Toroidal Continuously Variable Transmission

This paper presents a new concept of continuously variable transmission called the Ball Toroidal Continuously Variable Transmission (ball TCVT). The ball TCVT design is derived from the half-toroidal traction drive (Conventional TCVT). It embodies a new construction principle for the friction element engaging with the toroidal discs. The conventional rollers are being replaced by sphere / balls / cage assemblies. This new construction radically improves the transmission capability. Effortless speed ratio control, integrated neutral/clutch/reverse functions, increased versatility and reduced internal loads are the most significant gains. The paper will first describe the ball TCVT construction and explain its mode of operation. A second part will show the advantages and performances of the ball TCVT in comparison with the conventional TCVT. A third part will report the development status of this project.