SAF TRAKe: Additional Electric Drive

Emissions, fuel consumption and particle contamination are highly topical in the

commercial vehicles industry. Planned legal regulations additionally motivate

research and development: The new regulations stipulate the further reduction or

complete prevention of environmental contamination and emissions. To allow, for

example, ports and airports to meet their overall emissions balance in future, they

would have to only use zero-emissions vehicles in their internal logistics.

“Partially or fully electric commercial vehicles are a perfect solution for these requirements.

We are starting out with two new electric axles for trailers,” says Olaf

Drewes, Head of Pre-Development at SAF-HOLLAND. With regard to noise and

exhaust emissions, the new axles work towards supporting the legal requirements

of tomorrow. This also applies to the challenges of inner-city deliveries at

night, for example for the transport of chilled goods.

Recuperation as additional power source

Recuperation of energy, as during braking, transforms the motion energy of the

vehicle into electrical energy, for example during thrust phases. The energy is

stored in a lithium-ion battery and then used for auxiliary units in the trailer, such

as heaters, tail lifts, pumps or cooling systems.

With recuperation, almost all of this

energy can be generated during driving.

Recuperation as an additional source of

power generation saves fuel while reducing

noise development and exhaust emissions

of the entire vehicle. If energy is only recuperated

during deceleration, the fuel consumption

of the tractor unit does not increase.

Benefits for vehicle manufacturers

SAF-HOLLAND provides its customers with an overall system that features an

optimum combination of operating strategy and components. In addition to the

electric axle and the power electronics, the package also includes the battery

system and the control unit. “For trailer manufacturers and vehicle operators, this

means that the system operates smoothly without competence problems at interfaces,”

Olaf Drewes explains.

The drive unit does not have to be removed for uninstalling the hub unit and

wheels. Wear parts such as brake pads or brake discs are identical to the nondriven

axle components from SAF-HOLLAND – ensuring and simplifying spare

parts supply. In addition, SAF-HOLLAND will offer a service and training concept

which is specially adapted to the electric axles.

Trailer axles with electric generator and electric drive

SAF TRAKr uses a high-voltage generator module (400 V) for electric recuperation.

The new electric axle is primarily intended for refrigerated vehicles: It allows

cooling units to be temporarily operated with only electric power. This prevents or

reduces noise and exhaust emissions while also extending the service life of the

cooling unit components.

In addition to recuperation, SAF

TRAKe, the trailer axle with auxiliary

electric drive (maximum 147 kW), supports

the main drive of the tractor unit

on hills and on difficult terrain. “Bringing

the electric drive into the trailer as well

has great benefits for traction and stability,”

explains the Head of Pre-

Development at SAF-HOLLAND.

Modular electric axles

The electric axles from SAF-HOLLAND have a modular design and are equipped

with standardised interfaces. This allows them to meet all customer requirements

in the different variants. The axles will be available with the electric modules with

50 kW or 147 kW and also

- with different disc brakes and drum brakes for 19.5” and 22.5” tyres

- with different air suspensions such as SAF INTRA or SAF MODUL

- with different wheel connections and offsets for single and twin tyres.

The two axles are designed for axle loads from nine to twelve tons.

In light of the new emissions regulations and increasing fuel costs, electric axles

are a good investment in the future. SAF TRAKe and SAF TRAKr are designed

for the transport world of tomorrow: The new electric axles from SAF-HOLLAND

use recuperation to use energy efficiently, lower emissions and decrease fuel

consumption. SAF TRAKe uses an integrated additional drive to support the tractor

unit on difficult terrain and poor road conditions.