Meeting market requirements
The demand for ’A’, ‘B’ and ‘C’ segment front wheel drive (FWD) passenger vehicles will significantly increase in the next decade primarily due to growing demand in the fast developing Asian and Far East economies. Transmissions for these markets must deliver excellent drivability and fuel economy within a small, lightweight package that is also robust and reliable. Furthermore, these transmissions need to be innovative, user friendly and offer value for money as manufacturers look to adopt advanced technology in the new vehicles being developed.
Across the industry, car makers are looking to the next stage in the evolutionary process of transmission development – beyond the traditional manual transmissions, stepped ratio automatic transmissions, belt CVT's and chain CVT's - which fail to meet future requirements in at least one of the above areas.
TCVT solution
To address this opportunity Torotrak has developed the Toroidal Continuously Variable Transmission (TCVT) – based on the proven technology of rolling contact ‘disc and roller’ traction drive, rather than the more expensive belt or chain variators, and offering significant benefits and competitive advantages. TCVT is a low cost, lightweight, fuel efficient, compact transmission with excellent torque capacity which offers high levels of drivability, refinement and fuel economy.
Components of the TCVT
To achieve the package, cost and simplicity targets the TCVT comprises of only four elements:
- The Full Toroidal Traction Drive Variator
- A hydraulic block
- A clutch pack
- A final drive
This has resulted in:
- A stepless automatic transmission - with a wide ratio spread of 6.25
- Overall transmission reduction ratio in forward and reverse of 16:1 – delivering excellent gradeability and low speed performance
- A large overdrive capability – for optimised fuel economy and relaxed cruising
- A transmission weighing less than 50Kg – for example offering a design length of 345mm with torque capacity of 150Nm to satisfy typical 'A', 'B' and 'C' sectors.
