The new EQS SUV: quiet-running and vibration comfort

Apr 19, 2022
Stuttgart

The EQS SUV is designed to meet the highest standards of quiet-running. The performance specifications therefore already defined a number of measures, including special acoustic foams in some of the profiles of the body shell as well as the encapsulation of the eATS at the front and rear. The drive units are doubly insulated using rubber mounts. Ramps in the underbody panelling reduce noise from chippings thrown up in the wheel arches.

Even the design of the electric powertrains (eATS) takes quiet-running and vibration comfort (NVH - Noise, Vibration, Harshness) into account. The magnets are arranged inside the rotors in an NVH-optimised way (known as 'lamination'). This also reduces the use of rare earths. The shape of the winding, what is known as the stator tilt, also supports vibration comfort, especially at low speeds. The coils in the stator are at an angle in relation to the permanent magnets of the rotor. This reduces the occurrence of what is known as detent torques. They would lead to slight but unpleasant vibrations when driving very slowly.

In addition, the cover of the inverter has a sandwich design of three metal and plastic layers. The eATS are double-decoupled from the body via elastomer bearings.

The 4MATIC versions are equipped with an innovative supporting frame at the front axle. What is known as injection bonding is used as the joining technique. This involves joining the four main components - forged aluminium parts and extruded profile - to form a component with optimised vibration characteristics.

Highly effective spring/mass components provide continuous sound insulation from the cross-member under the windscreen to the floor of the boot. Acoustic foams are inserted into many members during construction of the body shell.

In addition, the main floor is designed with beads for NVH reasons. These prevent resonance of the surface and thus the occurrence of a corresponding structure-borne sound. Ramps in the underbody panelling reduce noise from chippings thrown up in the wheel arches.

Two acoustic dividers in the very large tailgate reduce booming noises. These could be caused by roadway excitations and are favoured by the large volume of the cabin including the luggage compartment. As in all Mercedes-Benz estate cars and SUVs, the tailgate's catch is decoupled.

In addition, there are the aeroacoustics measures, more on this in the specific chapter.

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