The replacement of internal combustion engines (ICEs) with electric drive units (EDUs) has led to new, unprecedented NVH challenges. In EVs using planetary gearboxes, high-frequency excitations – like torque ripple – and vibrations are transmitted from e-motors into the gearbox housing. These, in turn, can lead to comfort and refinement issues within the cabin.

To resolve NVH issues caused by EDUs and planetary gearboxes, Vibracoustic has developed an Elastic Ring Gear. This novel solution sits between the housing and the actual ring gear and has been proven through extensive simulation and material evaluation.

Vibracoustic’s Elastic Ring Gear is a tunable rubber component that offers multi-directional decoupling (radial, axial and torsional) to significantly reduce the transmission of vibrations. Extensive Finite Element Analysis (FEA) conducted by Vibracoustic’s engineering team demonstrated a wide range of sound-pressure reductions.

The Elastic Ring Gear provides high-frequency NVH optimization for EV powertrain systems with planetary gearboxes. It is extremely effective – potentially even making the additional acoustic encapsulations obsolete – due to its wide frequency working range.

For greater occupant comfort, the Elastic Ring Gear is an innovative and effective solution to manage EV NVH.

About Dampers & Decoupling Systems

Isolators and mass dampers are ideal for solving a wide variety of vibration-related challenges transmitted into the chassis from the road surface. Linear dampers are a strategic design element to counteract unwanted noise and vibrations – especially in lightweight structures.


Mass dampers are ideal for use in applications where vibrations need to be balanced with opposing inertial forces. In these configurations, an additional spring-mass system with the same frequency, but opposite amplitude, acts on the vibrating structure, effectively eliminating its vibrations. The way mass dampers work means they can be used in a wide variety of scenarios: transmissions, steering wheels, and even whole convertibles are just some of the applications that make use of this indispensable system to prevent Noise, Vibration and Harshness issues.

Active mass dampers are another way of improving comfort even further. They use a sensor placed on the vibrating structure and an ECU (Electric Control Unit) that controls a solenoid which is able to accelerate the absorber mass. This way, active mass dampers not only come with a design that weighs less and takes up less space than their conventional counterparts, but they are also able to adjust to variables such as additional cargo load, road surface excitation, and temperature.

Decoupling solutions for auxiliary components can address new NVH challenges especially in electric vehicles. Here auxiliary systems like coolers, pumps and compressors are not belt-driven anymore and auxiliary noise and vibrations are significantly more noticeable due to the lack of the masking noises of the combustion engine.