TCVT is a highly efficient, power dense, lightweight transmission with a low parts count. It is based on a simple arrangement within a small ‘package’ that provides a wide ratio spread, leading to excellent fuel economy. TCVT incorporates many aspects of innovative design to deliver low cost and simple operation.
Direct Connection To The Engine
One of the innovative aspects of TCVT is the direct connection of the engine to the input side of the variator with the clutch pack being located on the output side. This layout gives two key benefits:
- The variator rotates whenever the engine is rotating – even in neutral. This results in a robust variator that cannot be damaged by ‘shock loading’ on launch
- The clutch pack has two clutches - one for forward and one for reverse – with a drive chain for forward drive and a gear drive for reverse. This results in the elimination of a separate reversing mechanism.
Fixed Ratio Reverse
When the reverse clutch is engaged the variator ratio is maintained at a low ratio, thereby providing a fixed ratio reverse capability with the vehicle speed changing with engine speed. Therefore, unlike alternative variable drive transmissions, there is no need for additional gearing, thereby providing simplification, a reduction in components, cost savings and weight benefits.
A Stepless Automatic Transmission
Fixed ratio automatic transmissions and dual-clutch transmissions operate within the limitations of their fixed gearing, meaning that the engine seldom operates at its most efficient point.
In the TCVT, transmission ratio is continuously varied independent of engine speed. It has a large ratio spread of 6.25 that enables optimised engine operation and performance at the optimum fuel economy point, whilst also delivering efficient engine operation with high transmission efficiency – a key difference to traditional CVT designs.
Reduced Parts and Weight
TCVT utilises a simple mechanical ‘end-load’ device to clamp the variator together. This system reacts automatically to provide the necessary clamping load within the variator and is more efficient than other methods employed in other transmission designs.
In addition, the rollers are controlled by a simple, single hydraulic actuator – eliminating the need for independent hydraulic control of each roller. These innovations have reduced significantly the parts count, complexity and cost.
