An extra-
dose of

Better mileage: Fuel savings of up to 15 percent

Less consumption – less noise: Electric drives offer considerable advantages, not only for the truck but also for the trailer. With the ­development of a family of electric axles, SAF-HOLLAND is preparing for the paradigm shift in transportation.

Better mileage: Fuel savings of up to 15 percent

Every liter of diesel saved counts. For freight forwarders, fuel represents the second largest cost after the driver’s salary. It’s no wonder that truck manufacturers today are all trying to determine whether electrified tractors have a positive cost-benefit ratio. So far, there has been little attention on the trailer, which still usually lacks its own drive. However, with the development of two electrified trailer axles, SAF-HOLLAND is now demonstrating that electric drives can also be worthwhile in a trailer. The commercial vehicle supplier has developed two concepts. The first is the SAF TRAKr, which has a ­capacity of 30 kWh and briefly up to 50 kWh and works as a generator during braking. The electricity obtained can be used to power electrical equipment in the trailer, such as a refrigeration unit. This differs from the second concept – the SAF TRAKe – which temporarily relieves the tractor and has a maximum capacity of 120 kWh.

Even the small e-machine in the SAF TRAKr can achieve considerable savings. Until now, diesel generators have been used for refrigerated trailers, which must also run while stationary, so that temperature-sensitive cargo does not spoil. If these generators were temporarily replaced with battery-­powered electric machines, not only would the forwarder benefit, but also the environment. Battery-powered electric machines emit no exhaust fumes and significantly lower noise. This is not a niche application either: every fifth newly registered trailer in ­Europe today is equipped with a cooling unit. The amount of fuel saved when using the TRAKr ­depends on the respective application. “There are several factors involved,” explains Olaf Drewes, who is responsible for Advanced Research & Technology at SAF-HOLLAND. “The cooling capacity required can differ considerably, depending on the region and the season.” The more powerful SAF TRAKe is always the option used when a particularly powerful drive is required, for example when a truck is driving ­uphill and has to accelerate. The electric motor provides up to 4,100 Nm additional torque to the wheels at lightning speed. The additional support is also welcome when a truck and trailer combination is in the inner city and needs to operate purely electrically to protect residents from the noise of delivery trucks. SAF Holland sees some interesting applications not only for food but also for automotive transporters. In the latter, the electric drive in the trailer could also quietly power the hydraulics for the lift pump.

This is an advantage when loading and unloading the transporter in the city because deliveries can then take place at night. LOHR Industrie is working together with SAF-HOLLAND and the SAF TRAKe to make these types of applications a reality.

  • 1Wheel head without changes to series model at wear parts and brakes
  • 2Modular design enables high flexibility
  • 3Engine-transmission unit with 50 kilowatts of maximum power

The SAF TRAKr supplies energy to the refrigeration unit, for example

Olaf Drewes, Director Advanced Research & Technology
A modular family of axles

SAF-HOLLAND’s electrified axles form a family of axles whose basic construction is identical. For example, the engine-transmission unit is located in the middle of the axles and is connected to the wheels via the axle shaft. “This gives us a high degree of flexibility in matching various customer needs,” says Drewes. The transmission housing is even part of the load-bearing axle housing, which saves weight and also makes it possible to keep the same bolting points as with conventional axles.

In the future, SAF-HOLLAND would like to be able to calculate which axle represents the right solution for which customer by using a simulation program. This program is currently under development in cooperation with the Technical University of Braunschweig. The software takes into account the typical routes, including any slopes that occur and calculates the ultimate fuel savings expected for a specific battery size. “Our goal is to advise the customer on the optimal configuration,” says Drewes. “An average savings of 15 percent is quite realistic.” The additional weight of the trailer is expected to range between 500 kg and 1,000 kg, depending on the version of the axle and battery size. There are however efforts to expand the current regulations to take into account the use of electrical systems in the trailer. Trucks and tractors may be allowed to weigh up to 1,000 kg more due to the electrical components that do not reduce the permissible payload.

The first hardware tests are also currently underway. There is one thing SAF-HOLLAND is sure of and that is it will be a system provider for electrified axles in the future, which include the parts for the battery, thermal management and electronic control system. “All components are coordinated,” assures Drewes. “That’s why we’re constantly expanding our team and our know-how.” When the time comes to IAA 2020, this work will have paid off: SAF-HOLLAND’s e-axles should be ready to start production.

Three questions for Marie-José Navarre, LOHR Industrie S.A.

LOHR Industrie has been active in the design, production and sale of freight transportation systems for more than 50 years. The LOHR Group, headquartered in Alsace, has around 2,000 ­employees worldwide. LOHR Industrie works together with SAF-HOLLAND in the ­development of electric trailer axles.

Marie-José Navarre is Deputy Managing
Director of LOHR Industrie S.A

What is LOHR Industrie’s motivation for the application of e-axles to its trailers?

LOHR Industrie: Axeal (AXle Electric Assist Lohr) is totally independent from the tractor, providing power ­assist during acceleration and regenerative braking. It improves driving comfort and increases performance by reducing fuel consumption.

The central mechanical system includes a differential, a reduction gear and a power take-off which can be coupled when halted to drive a peripheral (e. g. hydraulic pump). When halted, the electric motor can be disconnected from the transmission to drive a peripheral (e. g. a hydraulic pump) required to operate the trailer for example.

What does LOHR Industrie’s roadmap for the ­introduction of this technology look like?

LOHR Industrie: We will equip 3 car-trailers in the first quarter of 2019 and gradually our new range of car-carriers in the middle of this year. They will be delivered for three operators, one in South Africa, one in the United States and one in Europe. Three different uses in terms of loading’s performance and complex urban environments in order to get a lot of experience feedback.

Why did you choose SAF-HOLLAND as a partner for the realization of your vision?

LOHR Industrie: SAF Holland has been working with LOHR Industrie for over 20 years. Its international alignment and its ­commitment to develop different e-mobility solutions naturally made us choose SAF-HOLLAND as a partner for Axeal ­development.