KEY DIFFERENCE: This is the CVT transmission CVTech developed for India's Tata Motors Nano micro car. All is in the two pulleys' diameter variation.
MONTREAL, Que. –Forget about the Beatles or the Rolling Stones. The British invasion in the trucking industry takes the form of a brand new generation of automatic transmissions coming from the UK.
Most of us are familiar with Continuously Variable Transmissions, or CVTs, that are becoming more common in passenger cars. As the name suggests, the transmission does not change from one gear to another but continuously varies the diameter difference between two pulleys driving a belt, thus changing the transmission’s ratio in limitless ways instead of being restricted to changing from gear A to gear B.
In addition to working more smoothly with the engine than a traditional automatic transmission, a CVT also offers the advantage of enhancing the fuel economy of the vehicle (roughly 5% in passenger cars), because it always runs at peak performance.
So, why don’t we have CVTs on trucks? Truck News asked Andre Laramee. The man knows a few things about CVTs, since his Drummondville, Que. company CVTech, has been chosen by the Indian Tata Motors to equip its famous Nano micro car with a CVT transmission.
“We use regular belts and absolutely no lube is needed for the transmission. They would not work on a truck with much higher torque,” he says. “In this kind of application, the metal belt needs to be lubricated but, because of the high torque and the metal shearing that occurs, the oil deteriorates very rapidly. There is still a lot of work to be done to find a lube that will handle all that.”
It definitely seems like there are still challenges. Here is what Paul Olexa, vice-president driveline sales and marketing at ZF, had to say: “ZF developed several CVTs and had them in production for passenger cars. In commercial trucks, the torque and cost would be a concern. From a commercial vehicle point of view, we are still focused on conventionally geared transmissions.”
From CVT to IVT: Allison steps in
After years of research and development, a company called Torotrak based in Lancashire, U.K., found the solution to the puzzle and came up with a CVT-derived transmission that’s called an Infinitely Variable Transmission, or IVT.
Truck News got in touch with Torotrak’s marketing manager Lin Collier and asked her what the difference is between a CVT and an IVT. Here’s what she had to say: “The core of any transmission using Torotrak’s technology is the traction drive ‘toroidal variator.’ Unlike conventional manual or automatic gearboxes with their toothed gears, this variator incorporates smooth, saucer-shaped discs and circular rollers. The variator allows the transmission to deliver a stepless range of ratios to meet all driving conditions. The simplest form of transmission using a toroidal variator is a CVT. This offers a ratio spread of approximately seven and requires a starting device such as a clutch or torque converter to launch the vehicle from rest.
“An IVT is a more sophisticated form of transmission where the variator is used in conjunction with an epicyclic gear set to provide a ‘geared neutral’ function with a seamless transition from reverse to forward motion. A typical IVT is configured to provide a ratio spread in excess of seven and provides high levels of overdrive gearing. With an IVT, no starting device is required. A specially-developed oil-like fluid, with unusual lubricating and traction properties, ensures grip between the rotating rollers and discs to transfer torque through the transmission from the engine to the driven wheels. The result is smooth power delivery, faster acceleration, improved fuel economy and reduced emissions.”
Seems complicated? Indeed it is. But the most important thing is that it does work. Enough for Allison to invest a huge amount of money to acquire the right to manufacture and sell these IVTs on the North American market and around the world.
We’re talking big money here, points out Collier: “The total value of the licence fees to be paid to Torotrak under the agreement, should Allison take up all of the licensing and exclusivity options on offer, will be in the region of 18m to 28m (CDN$32 to 50 million). Additionally, royalty payments will be made to Torotrak for every Allison transmission sold under the new arrangement.”
At the signing of the deal, Dick Elsy, Torotrak’s chief executive, said: “This is the most significant endorsement of our technology thus far. Allison is the world leader in commercial vehicle transmissions and the agreement provides us with access to large production volumes in this high value sector. Torotrak will now focus its technical expertise on transferring skills and knowledge to Allison to help it achieve volume production in the shortest possible timescale.”
Lawrence E. Dewey, Allison’s chairman and CEO, added: “We are excited about working with Torotrak to incorporate their unique technology into a new family of products that will offer our customers around the world new features and benefits.”
Major fuel savings on the horizon
Among these benefits will be fuel savings. James Batchelor is the commercial director at Torotrak. He confirms the figures evoked by his colleague when she said: “When applied to a mid-sized bus, Torotrak’s transmission technology has demonstrated fuel savings of 19% (when compared to the standard production model) over the official UK bus cycle.”
But what about trucks? Batchelor says: “Fuel savings depend heavily upon the duty cycle of the vehicle (and, of course, that the transmission in subjected to). For distribution-type trucks, we would expect the fuel saving to be similar to that achieved in our prototype bus application. For heavy haulage applications, the high efficiency of a Torotrak 4-mode IVT combined with the very tall overdrive ratios that the IVT enables is also expected to provide substantive economy gains over today’s technology.”
Better than an AT, at a lower cost than an AMT
When we asked Batchelor to range the price of an IVT transmission (even though the final decision will be made by Allison, since it will be the corporation selling them), he indicates: “The final cost (or selling price) will depend greatly upon the application, the manufacturing/ sales volumes and the cost-to-manufacture performance of our various licensees.”
“However, as a guide, we would expect the manufactured cost of a commercial vehicle IVT to be very much closer to the cost for an equivalent automated manual transmission (AMT) than it would be to the cost of an existing (planetary gear-set based) automatic transmission (AT). In short, all of the benefits -and more -of an AT but a cost close to that of existing, less expensive AMTs. And, of course, as sales volumes of IVTs increase in this sector, then we would expect further unit-cost reduction as a consequence of greater industrialization, scale economies, increasing design experience, commercialization pressures, and so on.”
According to Batchelor, it will take at least a year before Allison is ready to launch the IVT transmission on the market.
Tata Motors and a Euro manufacturer in the race
Allison is not the only licensee of Torotrak’s IVT technology. In fact there are three of them. Torotrak also sold the licence to Tata Motors and to a major European bus and truck manufacturer whose name couldn’t be disclosed for confidentiality reasons.
Truck News asked Tata Motors to elaborate on how it would use the IVT technology in its commercial trucks but the Indian company didn’t want to comment, obviously for competitive reasons.
“Tata Motors does not have any information to share at this stage”, said Debasis Ray, head of corporate communications, yet confirming: “Yes, Tata Motors is a licensee of Torotrak’s IVT technology.”
As for the “mysterious” European truck and bus manufacturer, Daimler doesn’t seem to be the one. “IVT is not a system we offer within our Mercedes-Benz Truck products,” said Uta Leitner, from the Stu
ttgart-based Global Business Communications Daimler Trucks and Buses department.
No official confirmation yet, but all signs tend to point that Volvo is not involved either -the Swedish company invested a lot of time and resources in its I-Shift automated manual transmission.
With the proliferation of truck transmission offerings -Allison already offers fully automatics with torque converters, Eaton has a complete line of manual transmissions, automated manual transmissions from the UltraShift family and now the “almost automatic” UltraShift Plus, Allison is getting ready to market its IVT -one might think that the competition will be fiercer than ever on the transmission front.
And hopefully for fleets and owner/operators, this might translate into price reductions.