Why Has Nvh Become A Paramount Factor?
Electrification has already started to have a noticeable impact on the global automotive industry.
As a result, the drivetrains of hybrid (HEV) and full electric vehicles (EV) are facing many challenges, like increased requirements for NVH in high speed e-Drives and the need for performance improvements to deal with recuperation requirements.
In EVs and HEVs noise from ICE is intermittent or no longer present, and the contribution of transmission noise to overall vehicle noise becomes dominant. Noise has thus become not only a mechanical issue for the performance of the transmission, but also a comfort issue for the driver.
What is true is that the number of gear wheels is significantly reduced in electric vehicles due to the use of one or two-speed reducers instead of the classic manual, automatic or twin-clutch gearboxes. In return, these are loaded with torque and rpm not previously found in high-volume production.
Marposs Nvh: Noise Testing Of Individual Gears
In more general terms, Noise Vibration and Harshness (NVH) is a method of investigating the vibro-acoustical behavior of a single component or of an assembly. Typically, this method of analysis is used to objectify the assessment of the vibrational behavior of mechanical groups, especially due to mechanical power transmission.
Marposs NVH gear tester, that works on the Single Flank testing principle of one master gear meshing with the component under inspection, is able to detect macro-geometry (nicks, runout etc.) and micro-geometry (gear mesh excitation, ghost orders) defects that are responsible of gear whine and noise phenomena.
The ability of achieving high values of torque and rotational speed and the possibility to adjust them at will during testing, is one of the major benefits of the application, which allows testing the gears at operating conditions almost comparable to those found in the final e-Drive.
A very stiff structure to become non-sensitive to external interferences and a highly configurable software make Marposs NVH gear tester at the forefront of technology in the sector, capable of correlating data with the End Of Line test rig.
Why Testing Gears At Component Level?
Why evaluating NVH on component level could represent a benefit than making the analysis directly on the final assembly?
Because identifying defects (like tooth micro-geometry errors) on the single component could avoid issues hard to solve at the assembly stage, when it might be too late to recover the whole assembly unit.
This represent an invaluable benefit in terms of time and money saved for our customers.
Learn more about Marposs NVH