Engine Device Helps Emissions Reduction

A UK company has developed a device that enables vehicle engines to run at optimum conditions for fuel economy and emissions reduction, helping the environment worldwide. As well as that, the car's performance is significantly improved.

The Torotrak company's technology is called infinitely variable transmission (IVT) and has the potential to become a direct replacement for all automatic vehicle transmissions worldwide. It is a fully scaleable concept and could work just as well in small cars as in a 40-tonne truck.

The company is the world leader in the design and development of traction drive IVT systems and says the technology offers the automotive industry significant improvements in fuel economy, performance and smoothness combined with innovative driving control features.

Essentially, IVT allows control of the complete vehicle powertrain and enables optimisation of its efficiency. This is unlike conventional vehicles in which the engine and transmission are controlled separately. The IVT's software determines the torque required at the road wheels and then requests the torque from transmission. This ensures that the engine can deliver power at its most efficient point.

The company's IVT is an advanced CVT in that it has a continuous range of ratio that provides a smoother drive and enables the engine to run at optimum conditions. The ratio range is provided not by a system of gears, as found in a conventional automatic transmission, but by a variator that consists of a set of discs and rollers and is termed a full toroidal variator.

Inside the variator are two pairs of discs. The space between each pair of discs forms a doughnut shape - or toroid. Within each toroidal space there are three rollers. These rollers transmit drive from the outer, engine-driven discs to the output discs located in the centre. The rollers transfer power between the input discs and the output discs via a traction fluid.

Each roller is attached to a hydraulic piston. The pressure in the pistons can be increased or decreased to create a range of reaction torque within the variator.

Unlike belt CVTs, the full toroidal variator has no torque limitations and is configured in the IVT to provide a full range of ratio from reverse, through stationary and up to high overdrive, hence the term: infinitely variable. This means there is no need for a starting device such as a torque converter and cruising at about 130 kilometres an hour is possible with an engine speed of around 1,200rpm (the same car fitted with a conventional automatic would have an engine speed of around 2,500rpm at the same conditions).

The Torotrak IVT enables 20 per cent fuel economy compared with a standard four-speed automatic; computer modelling predicts a 10 per cent improvement compared with a six-speed automatic. It achieves this fuel economy improvement by enabling the engine to run at optimum power conditions. There is no compromise to either the driver or the car manufacturer in terms of driveability, vehicle size, performance, functionality and cost. Indeed, there are many enhancements to vehicle driveability and with many added features.

Torotrak has undertaken an extensive programme to develop and test the IVT. Prototypes fitted to vehicles have been demonstrated to all the major car and transmission manufacturers, each of whom said that it exceeded their expectations.

Tests carried out by a vehicle manufacturer show a significant fuel economy improvement and a reduction in CO2 emissions.

The company recently won the Carbon Trust Innovation Award. The Carbon Trust works with UK business and the public sector to cut carbon emissions. Set up by the government to help the UK meet its climate change obligations, the Carbon Trust creates practical, business-focused solutions to carbon emission reductions.

Dick Elsy, chief executive officer of Torotrak, said: "This award is recognition of the significant reduction in the CO2 emissions that Torotrak's game changing technology can provide for the world's vehicles."