Prob­lem: Audi­ble and per­cep­ti­ble vibra­tions

Goal:  Increase in ride com­fort

The e‑axle dri­ve is becom­ing increas­ing­ly pop­u­lar for use in e‑vehicles: With its low­er weight, it promis­es more pow­er and range.
In the e‑axle dri­ve, the three dri­ve com­po­nents — elec­tric motor, trans­mis­sion and invert­er elec­tron­ics — are com­bined to form a com­pact unit. Due to lim­it­ed space, the indi­vid­ual com­po­nents of the entire dri­ve unit must be opti­mal­ly matched in terms of strength, weight and sound trans­mis­sion. Oth­er­wise, audi­ble and per­cep­ti­ble vibra­tions can occur that affect ride com­fort. The inves­ti­ga­tion of tor­sion­al vibra­tions in the e‑axle dri­ve is there­fore fun­da­men­tal for the analy­sis of noise exci­ta­tion as well as NVH (noise, vibra­tion, harsh­ness) behav­ior.

In the dia­gram, the speeds at the elec­tric motor, at the gear­box out­put and at the inter­me­di­ate shafts are record­ed in high res­o­lu­tion. The clock fre­quen­cy of the ROTEC speed card is 12.3 GHz. Thus, the tor­sion­al vibra­tion of the shafts as well as the tor­sion­al angle between two shafts can be mea­sured in the µrad range. The trans­mis­sion error (TE) of the gears can thus be dis­played with the high­est accu­ra­cy. This para­me­ter is impor­tant for describ­ing the exci­ta­tion of the gear howl­ing (GWN) and indis­pens­able for a deep­er under­stand­ing of NVH behav­ior. At the same time, struc­ture-borne sound sig­nals are record­ed with an accelerom­e­ter and micro­phones and then joint­ly eval­u­at­ed in the order and fre­quen­cy ranges. For the mea­sure­ment of elec­tri­cal quan­ti­ties such as cur­rents and volt­ages, we use the high-pre­ci­sion HV mea­sur­ing probes of our part­ner com­pa­ny KLAR­IC.

The record­ed mea­sured val­ues are eval­u­at­ed in the time domain. At the same time, the acoustic behav­ior is ana­lyzed.

Fur­ther­more ROTEC ENGI­NEER­ING pro­vides you with sup­port and tech­ni­cal engi­neer­ing know-how for prob­lems relat­ed to vibra­tion analy­sis of engines, trans­mis­sions and dri­ve trains. With our know-how, we make a valu­able con­tri­bu­tion to your prod­uct in the areas of tim­ing gear val­i­da­tion, valve train opti­miza­tion, clutch design, trans­mis­sion errors (TE), trans­mis­sion opti­miza­tion, oil sup­ply opti­miza­tion, pow­er­train mea­sure­ment and opti­miza­tion, cur­rent and volt­age analy­sis, and the appli­ca­tion of mea­sure­ment tech­nol­o­gy.