Blood, sweat and gears

Torotrak and Antonov have been trying to convince car makers of the merits of their innovative automatic transmissions since the early 1990s. Both claim improved fuel economy, but there the similarity ends.

General Motors’ decision last month not to take out an internal development licence for Torotrak’s innovative infinitely variable transmission seemed like a major setback.

The City certainly saw it that way, not least because of expectations raised by Torotrak itself, and its share price fell by two thirds. But the markets got it wrong, says Torotrak chief executive Maurice Martin. Torotrak, he says, never really expected the big car makers like GM to go into production with the technology themselves.

‘GM conducted the best independent assessment of the technology and concluded it works. They were very complimentary about Torotrak as a company. But they said there’s still work to do on the production engineering side: to reduce in size, cost and weight to make a deliverable product. These are skills we don’t have: we need a car maker or tier one supplier.’

Business risk

GM already manufactures automatic transmissions by the million at very low cost. ‘IVT represents a business risk,’ says Martin. ‘Without customer reaction it would be foolish for GM to manufacture in volume.’ This leaves a tier one supplier, which could offer the technology to a range of car makers, as the only way to get the system into volume production.

Two weeks before the GM announcement Torotrak had signed a licensing agreement with leading Japanese gearbox manufacturer Aisin. GM, it seems, played a behind-the-scenes role in persuading Aisin to sign up. ‘The GM announcement looked like bad news. But we’re overjoyed we’ve got GM to encourage a major tier one supplier to join us,’ says Martin.

The shift of focus to tier ones was always planned, says Martin, but Torotrak was engaged in resolving a ‘chicken and egg conundrum’. ‘We had a strategy to work with tier ones as soon as we could, but they were not prepared to get involved until the big car makers were convinced.’ Convincing the car makers has been the focus of the company’s development activities since the mid-1990s. ‘For 10 years that is the loop we’ve wanted to close,’ says Martin.

A fleet of Torotrak-equipped vehicles is about to be despatched to Ford for assessment. ‘I would be very surprised if Ford made any different decision to GM,’ says Martin. The Premier Automotive Group – which manufactures Ford’s premium brands such as Land Rover, Jaguar and Volvo – is now seen as the most likely division to adopt the technology first, given the troubles the world’s second-biggest car maker is facing globally. A premium German manufacturer has also evaluated the technology and concluded it is ‘concept ready’.

Meanwhile, having signed up Aisin, Torotrak has abandoned contingency plans to go into limited production itself of up to 10,000 units annually for pilot sales trials. In the past month 36 staff who would have been engaged in this process have been made redundant, leaving about 100, including 60-70 engineers.

A third piece of the jigsaw is tier two bearing supplier Koyo Seiko, which is expected to make the variator.

One-to-one basis

Martin remains reluctant to suggest a date when Torotrak is likely to reach the market, but stresses that the firm has enough money to continue to fund development until 2010. In addition, the cash raised in the company’s flotation in 1998 enabled it to fund the most recent, ‘series 3’ phase of development itself.

This means it can go public with the results, and it plans to let the press drive Torotrak-equipped cars for the first time later this spring. In previous phases it had worked on a one-to-one basis with car makers so that the results were confidential.The target market remains, initially, pick-ups and four-wheel drive ‘sport utility vehicles’ in the US. These form 50 per cent of the vehicle market in the States, though they are essentially light trucks.

Because they are heavy on fuel, they are likely to be hit hard if proposals go ahead to tighten regulations that govern car makers’ ‘fleet average’ fuel economy. hence they are likely to benefit from Torotrak’s fuel economy gains, said to be at least 15 per cent. In addition, because such vehicles are built on separate chassis, the problems of packaging which would apply to a typical front-wheel drive saloon do not arise.

Torotrak says series 3 brought about big improvements in the technology, notably on the control software. This can be used to give the transmission different characteristics, says Torotrak licensing director Geoff Soar. Initially it is likely to be designed to mimic the feel of a conventional torque converter type transmission, but once market acceptance has been achieved the control strategy could be changed to gain even better fuel economy by letting the engine run at optimum revs for more of the time.

But the engine will not then respond to pressing the accelerator in the way the driver expects, and it will take some time for the market to get used to this.

How worried is Torotrak about the competition from Antonov? ‘We don’t really see them as a competitor,’ says Martin. ‘We’re looking at different markets; we have different benefits which Antonov doesn’t provide. We both claim improved economy, but in engineering terms Torotrak offers a system that opens the future. Antonov is still a stepped ratio automatic transmission. It’s ingenious and low cost, but unsophisticated.’

Weeks after GM declined a development licence from Torotrak, Antonov sealed a deal with Honda which will allow the car maker to go into production with the Antonov transmission across its product range.

Antonov had been working with Honda since 1992; in 1996 Honda began an internal development programme which led to last month’s production licence. But now Honda has committed itself other car makers will not be far behind, expects Antonov managing director Mike Emmerson. ‘All the car makers are looking at every technology. Honda isn’t years ahead of the rest. We expect the Honda licence will cause an acceleration of the evaluation process by other companies.’ Evaluation is also under way by GM, Ford, Suzuki, ZF, Aisin, Matra, and BMW.

In fact, the company now has three production licences out. NZWL, a gearbox supplier to DaimlerChrysler, is expecting to supply the Antonov drive for the Corbin Merlin, a three-wheeled US commuter car which is just going into production. Corbin projects sales of 30,000 vehicles annually by 2005.

A third production licence has been taken by India’s Gajra, potentially for an Indian version of a Suzuki car.

Meanwhile Antonov has set up a strategic alliance with tier one supplier Luk, with the intention of adapting its transmission control systems to the Antonov gearbox.

Easier task

Though Antonov seems to have made much more progress than Torotrak, it also has an easier task. The Antonov transmission is in effect a simplified version of existing technology. All its parts can be made on any existing transmission production line, so manufacturers such as Honda can go into production with little risk.

Unusually for the car market, where new technology is normally introduced first at the top end of the range and filters down, Antonov is targeting the market for cars of less than 2 litres, where there is little take-up of automatic transmission, because existing types take up too much power, space or cost too much. Antonov believes the share of automatic transmissions in this segment could rise from 24 per cent now to 50 per cent.

Royalties for Antonov would be expected to be around $20 (£14) per transmission, so that a five per cent market share would bring in revenues of $56m (£39m). But with a France-based development team of only 20, the break-even point is low.Emmerson also plays down the potential rivalry with Torotrak – for now at least. ‘In the short to medium term we appear to have very different introduction strategies. We were never in a situation where we were competing with Torotrak for a development budget.’

‘In the long term in the car industry there tends to be one domination technology simply because of economies of scale. So in the short term I don’t see us competing, but in the long term we may do.’

Sidebar: How the transmission systems work


Roumen Antonov, inventor of the Antonov gearbox, was studying the blueprints of an old automatic transmission when he made an amazing discovery. For decades gearboxes have used helically cut gears, because they are quieter than straight-cut ones. But this introduces additional forces which try to disengage the gears. These forces have always been seen as having no useful role. ‘Antonov couldn’t believe these forces had never been used,’ says Antonov Automotive Technologies managing director Mike Emmerson.

He saw that the axial force could be utilised to initiate gear changes, eliminating the high-pressure hydraulic system used now, which saps power and adds weight and cost. The axial force is proportional to engine torque, which combined with engine speed information tells the gearbox when to change gear.

The advantage is that the technology is all entirely familiar to automatic gearbox makers, but it results in a significantly simpler transmission that can be smaller, lighter and cheaper. It can be put into any application in which a conventional auto box is used now, and any current electronic control system can also be applied to an Antonov box. No torque converter, another source of energy sapping, is needed.Eliminating the hydraulics has resulted in fuel economy improvements over a conventional automatic box with the same number of ratios of around 13 per cent. Yet the box is estimated to cost $650 (£457) to make compared to a conventional automatic’s $900-$1,000 (£630-£700).


The problem with existing automatic transmissions is that there is a fixed gear ratio between the engine and wheels, so the engine is never running at optimum revs.Torotrak’s toroidal drive has a built-in ability to be used to control torque. In a vehicle equipped with a Torotrak IVT, the driver no longer directly controls the engine through the accelerator pedal. Instead, the control software interprets a given accelerator position as a demand for torque, and this is passed to the variator which adopts a suitable position to provide the required torque with the engine at optimum revs. Fuel economy is improved by at least 15 per cent.

The variator is the heart of the transmission. It consists of two sets of three rollers running within two toroidal (doughnut-shaped) discs. The gear ratio is changed by altering the angle of inclination of the rollers using hydraulics. Forces are transmitted between the rollers and discs using a special oil called traction fluid, which becomes viscous under pressure. The variator uses bearing technology.

The second key feature is an epicyclic geartrain which allows the engine to be connected to the wheels even when the car is not moving, eliminating the need for a clutch and therefore potentially improving driveability.

Though the idea behind Torotrak has been around for 100 years, it has been made possible only by advances in technology: the traction fluid, bearing steels, and drive-by-wire control systems.