Bosch claims 9,000 litres of diesel savings through electrified axles for semitrailers

At the IAA commercial vehicles in Hannover, Bosch will be presenting an electrified axle that can be integrated into semitrailers. The electrical machine will be integrated into the semitrailer’s axles which would enable them to generate electricity during braking and feed it into the trailer’s power units. A cooling unit, if operated through this generated power could lead to a fuel-saving of 9,000 litres of diesel a year, according to Bosch. Bosch claims that this leads to reduced CO2 emissions and significantly less noise.

A primitive step towards automated trailers

Dr Markus Heyn, member of the Robert Bosch GmbH board of management said, “Bosch is making trucks’ rear axles electric and smart. Our electrification solution for trucks makes economic sense and shows how electromobility can work even in today’s trucks.” According to Bosch, the electrical axle is an important step toward automated trailer parking on logistics companies’ parking lots. Adding a powertrain to the axle means that the trailer can be shunted around the parking lot without a tractor.

The system also allows for remote-controlled electric driving on private property. The electric motor makes the trailer into an independent vehicle that can travel short distances and with the help of additional sensors attached to the trailer and installed at various points in the depot, it would be possible for these trailers to park themselves.

Smart electric motors for smart energy recuperation

Unlike in electric cars, the motors in the electrified axle work only intermittently, starting only if they can recuperate energy. This may be the case when driving downhill or braking, for example. As a result of this recuperation, which is an established technology in passenger cars, energy is no longer lost when braking, but is stored in a high-voltage battery. The electricity can be fed into the motors during hill starts, or power the trailer’s refrigeration unit, and in this way save a lot of fuel. 

This way, significantly less expensive production parts from passenger cars can be used in this trailer application as the electric motors are inactive most of the time, recuperating energy or providing assistance when starting or on ascents for only a few seconds or minutes every hour.

Electrified Semitrailer Axle

Bosch offers this technology either for new trailers or as a retrofit solution. According to sources, in Europe alone, roughly a quarter of a million trailers with a gross vehicle weight of more than 10 metric tons are newly registered every year. One in five of these is equipped with a refrigeration unit.