Features & Interviews

Electric alignment: The rise of eAxles

13 October 2022 #Features & Interviews

Going hand-in-hand with the large number of new electric vehicles available, manufacturers have recently unveiled a variety of new electric axle drives – or eAxles – for a wide range of weight classes.

The systems represent an efficient drive solution for battery-electric vehicles and hybrid applications, with the electric motor, power electronics and transmission combined in a compact unit directly powering the vehicle’s axle.

For example, Saietta recently revealed its high-tech fully integrated, modular eAxle Concept, developed for heavy-duty vehicle manufacturers.

The eAxle Concept benefits from two electric motors and added gearing – strategically placed back-to-back in the middle of the architecture. Both motors are connected to one wheel hub.

This design maintains the axle’s high torque vectoring capabilities while being packaged within the same footprint design as a conventional axle driven by a diesel motor.

As a result, Saietta’s eAxle Concept houses the entire powertrain at the rear of the axle, allowing OEMs the opportunity to make use of the newly acquired space to add extra batteries and battery cells, range-extender systems or optimise cargo capacity.

Edgar Ooijman, Chief Commercial Officer at Saietta HDE, said: “Saietta is working with vehicle manufacturers to apply its eDrive solutions to their products, helping them respond to regulatory and societal drivers to rapidly transition to zero emissions commercial transportation.”

Meanwhile, Allison Transmission has brought to market its the new eGen Power 130S, the latest product to be introduced to the company’s eGen Power family of fully electric axles.

Key components of the 130S include new suspension systems, V-rod brackets, banjo housing, brakes, wheel ends and axle spindle, designed specifically to support the heavier 13-ton gross axle weight rating.

The 130S uses a single motor to generate 225 kilowatts of continuous power, with a peak power of 325 kilowatts, and 26,000 newton meters of torque at the wheels.

It also features a two-speed parallel axis gear architecture, meeting application launch and highway cruise demands, while maximizing energy recovery through 100% regenerative braking capability.

Allison’s eGen Power line-up of e-Axles, which includes the 100D, introduced in 2020, as well as the 130D and 100S introduced in 2021, are modular and designed for installation and easy integration into existing vehicle chassis.

Heidi Schutte, Allison Transmission Vice President EMEA, APAC & South America Sales, said: “We understand that there is no one-size-fits-all approach when it comes to electrification and a variety of products will be needed to address the wide range of markets Allison serves.

“We are pleased to expand our eGen Power family of e-Axles once again in order to deliver an additional electric propulsion solution for European and Asia Pacific markets.”

Cummins recently launched its Meritor 17Xe ePowertrain, designed for heavy-duty trucks in the 4×2 and 6×2 segment, with capacity to support 44 tons of gross combined weight, or more in some applications.

The assembly also features a lithium iron phosphate (LFP) battery pack, a new arrival to Cummins’s battery line-up.

Cummins is integrating Meritor’s ePowertrain with battery and fuel cell electric drivetrains.

Amy Davis, Vice President and President of New Power at Cummins, said: “We are committed to bringing Cummins and Meritor electrified powertrain solutions to market as quickly as possible.

“Cummins and Meritor bring together the industry’s best, most economically viable decarbonised powertrain solutions that are better for people and our planet.”

German firm Bosch markets the eAxle city which is a compact housing unit for the electric motor, inverter, and transmission for smaller EVs.

Its power components utilize superior silicon carbide semiconductor technology to save energy and enhance efficiency.

Another one of its products, the eAxle performance, enables higher performance with scalable voltage levels of 400V and 800V.

Vehicle and trailer manufacturers have also been busy developing their own eAxles.

Volvo Trucks has unveiled a completely new, fully electric rear axle which allows even more batteries on the truck by integrating the electric motors and the transmission into the rear axle.

More batteries mean longer range and the additional space can be used for installing other components.

The manufacturer says it will start serial production of cab over engine trucks with the new e-axle in a few years from now and that it will complement the current line-up of battery electric trucks.

Jessica Sandström, SVP Global Product Management at Volvo Trucks, said: “This is a breakthrough for electric trucks and a clear signal that there will be a huge demand for public fast-chargers for heavy trucks in the near future, not least along highways.

“In a few years, we will add this new rear e-axle for customers covering longer routes than today.”

In addition, Daimler Truck has unveiled its first heavy-duty battery electric truck – the Mercedes-Benz eActros LongHaul – with a new e-axle and a range of 500kms, available in both a tractor unit and a rigid variant.

The new offering has more than 600kWh of battery capacity from three battery packs powering two electric motors as part of a new e-axle which can generate a continuous output of 400kW and a peak output of over 600kW.

Also, Krone has developed a prototype electric axle, supplied by its subsidiary business Gigant, and in collaboration with Trailer Dynamics, fitted to an eMega Liner semi-trailer chassis powered by a 600kW battery.

When the vehicle is moving forward, a sensor at the back of the kingpin activates the battery and electric motor to operate the e-axle.

Krone says this can save between 20% and 40% fuel or energy for the tractor unit and that the e-axle also recovers braking energy through recuperation.

In addition, Dutch moving-floor trailer manufacturer Kraker Trailers has developed a prototype e-axle hybrid trailer which it says has the potential to deliver 10-20% fuel savings.

The E-Force uses a 42kW battery, supplied by Super B, to operate the moving-floor.

Energy generated during braking is stored in a battery and used to power the centre axle during acceleration and when unloading.

Expect to see a greater number of increasingly sophisticated eAxles appear in the marketplace over the next few years as manufacturers look to make electric drives simpler, cheaper, more compact and more efficient.


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