motor

When I-Shift was launched in 2001 it was something that had never been seen before. Back then, few people believed in a transmission system designed exclusively for automatic gear-changing. Today, however, I-Shift is one of Volvo Trucks� most highly appreciated products worldwide.

This year, I-Shift is celebrating its 10th anniversary. Today no fewer than 80 per cent of Volvo�s FH trucks are equipped with the system, making I-Shift virtually a standard feature. At its launch in 2001, however, things looked very different. There were already a number of so-called AMTs (Automated Mechanical Transmissions) on the market, but they were all based on manual gearboxes adapted to permit automatic gear-changing. They were often not entirely reliable and customers complained. Vehicle manufacturers were forced to face angry customers who had paid a great deal of money for a transmission that caused problems.



Tailored for long-distance operations
However, Volvo Trucks believed in the concept of a transmission system designed from the very outset for automatic gear-changing. The first target was to adapt it for long-distance transport.

The company succeeded and in 2002, just one year after the system�s launch, 14 per cent of all Volvo trucks sold were equipped with I-Shift. This can be compared with its predecessor, Geartronic, Volvo Trucks� first AMT, which was only fitted to one per cent of all trucks sold by the company.

Sven-Erik Tibb was the main project manager throughout the development of I-Shift. �We created a totally new unsynchronised basic transmission and an integral control unit with all the electronics, sensors and so on. We then added software that was fully tailored for long-distance traffic. This gave us total control of the engine and gear-changing,� he recalls.


The new I-Shift was thus a combination of fairly straightforward, uncomplicated mechanics along with electronic control. �There are many benefits with I-Shift. In addition to lower fuel consumption, the system contributes to safer driving, which benefits everyone," says Ricard Fritz, Senior Vice President Strategic Planning and Business Development, Volvo Trucks.

�The driver is free to fully concentrate on the traffic and does not become tired from all the gear-changing by the end of the working day. I-Shift is also very easy to drive, and this is appreciated by both experienced drivers and those who are not so experienced," he adds.

Other advantages of I-Shift are that it changes gears very quickly compared with other systems on the market, there is no need for a clutch pedal, and there is software optimised for different types of driving.

Second generation
In 2005, when the second generation I-Shift made its appearance, the front and rear parts of the transmission had been redesigned to include a new clutch system and a new range-change unit. This provided greater capacity for higher gross combination weights and, consequently, I-Shift could now be fitted to trucks used for some heavier construction and forestry transport duties. As a result, the transmission also found its way into trucks with the 16-litre engine and not just vehicles with 9- and 12-litre power units.


Launch of third generation
The third generation was launched in 2009 and was tailored to match Euro-5. It featured a number of hardware improvements, together with new software which made the transmission suitable for additional, even more demanding assignments. It was now possible, for example, to rock heavily laden trucks free if necessary.

�From the very start, we had developed programs for different types of operation and customers were able to choose between the various programs. Each new generation added new applications and now even really heavy-duty construction vehicles like the Volvo FMX can be equipped with I-Shift,� says Sven-Erik Tibb, who today is section manager for drivelines and hybrids at Volvo.

�ke Zander, technical director at Volvo Powertrain, was also involved from the start. According to him, I-Shift can keep fuel consumption at the same level as the best driver on his best day with a manual transmission. The electronics make sure that the correct gear is always selected to enable the engine to work as economically as possible.

�The advantage when it comes to I-Shift is that it doesn�t have bad or good days. It provides the same fuel-efficient progress, regardless of who is driving or how the driver feels. What�s more, the driver does not need to apply any force to shift gear,� says �ke Zander.

So what does the future look like?
Euro 6 will soon be making its entrance, and transmission systems will need to be adapted to the new engines. �The next generation will be even more fuel-efficient. What�s more, we are going to consolidate, refine and stabilise what we have already achieved and further expand the applications for I-Shift,� promises �ke Zander.

| Volvo

Volvo Car Corporation is now taking the next step in the company's electrification strategy by producing test cars with Range Extenders - electric cars that are fitted with a combustion engine to increase their effective range.

The projects, supported by the Swedish Energy Agency and the EU, encompass three potential technology combinations. Tests of the various concepts will get under way in the first quarter of 2012.

"This is an exciting expansion of our increasing focus on electrification. Battery cost and size mean that all-electric cars still have a relatively limited operating range. With the Range Extender, the electric car has its effective range increased by a thousand kilometres - yet with carbon dioxide emissions below or way below 50 g/km," says Derek Crabb, Vice President Powertrain Engineering at the Volvo Car Corporation.



The company's technological developments in this area currently encompass three different technology combinations, with three-cylinder petrol engines being installed to complement electric drive to the front wheels. All the variants feature brake energy regeneration. The engines can run on both petrol and ethanol (E85).

Two of the solutions are based on the Volvo C30 Electric. In both cases, the standard battery pack has been somewhat reduced in size to make room for the combustion engine and its fuel tank.


Technical concept I: Volvo C30 with series-connected Range Extender
This is based on a C30 Electric with a three-cylinder combustion engine producing 60 horsepower (45 kW) installed under the rear load compartment floor. The car also has a 40 litre fuel tank.

The combustion engine is connected to a 40 kW generator. The power it generates is used primarily to drive the car's 111 horsepower (82 kW) electric motor, but the driver can also choose to let the generator charge the battery, thus increasing the car's operating range on electricity.

The Range Extender increases the electric car's range by up to 1,000 km - on top of the 110 km range provided by the car's battery pack.


Technical concept II: Volvo C30 with parallel-connected Range Extender
Here the car gets a more powerful three-cylinder combustion engine at the rear and a 40 litre fuel tank. The difference between this and the first solution is the parallel connection, whereby the turbocharged 190 horsepower engine primarily drives the rear wheels via a six-speed automatic transmission. This gives a better fuel efficiency rating when driving with the combustion engine cruising on the highway. Via a 40kW generator the battery can also be charged to give the car increased range on electricity alone.

Here too the electric motor is a 111 hp (82 kW) unit. The two power sources give the car more than 300 hp in total, and acceleration from 0-100 km/h of less than six seconds.

The Range Extender increases the electric car's range by more than 1,000 km - in addition to the range of up to 75 km provided by the car's battery pack.

Technical concept III: Volvo V60 with parallel-connected Range Extender
This is a solution whereby the entire drive package is installed under the bonnet at the front. The 111 hp (80 kW) electric motor is supplemented with a three-cylinder petrol turbo engine producing 190 hp (140 kW), a two-stage automatic transmission and a 40 kW generator. Power from the combustion engine drives the front wheels via the gearbox and recharges the battery pack whenever needed.

Up to 50 km/h, the car is always powered solely by electricity. The combustion engine is activated at higher speeds. What is more, it charges the battery pack when its charge drops below a predetermined level.

The battery pack is located under the rear load floor and it gives the driver a range of 50 km on electricity alone. The car also has a 45 litre tank for petrol or E85.

With this technology, the Range Extender increases the car's total range by more than 1,000 kilometres.

CO2-lean driving pleasure and comfort
The series-hybrid Range Extender in the C30 is part of an EU project in which the Volvo Car Corporation is the only car manufacturer among eight partners. The company's two parallel-hybrid Range Extender solutions are being developed with a grant of SEK 10.8 million (EUR 1.2 million) from the Swedish Energy Agency.

"These three projects allow us to evaluate the Range Extender's various possibilities. As with the C30 Electric and V60 Plug-in Hybrid, the goal is to make the cars exceptionally CO2-lean without compromising on customer requirements such as comfort, driving pleasure and practicality," explains Derek Crabb.

| Volvo