A suspected cooing sound was identified in the hybrid
powertrain under the idle charging condition. Data collection and analysis
confirmed that this abnormal sound was a cooing sound exhibiting engine half-order
characteristics. Analysis of the generation mechanism revealed that the cooing
sound originated from excitation by high harmonic components of shaft system
torsional vibration, which was then amplified through the coupling of hybrid
powertrain bending-torsional mode and EGR mode.
Consequently, three optimization schemes were put forward, including replacing
the flexible flywheel, adding a DHT connection bracket, and adding an EGR bolt
support point. These schemes successfully eliminated the abnormal cooing sound.
The analysis methodology and countermeasures provide significant reference
value for addressing similar NVH problems.
LI Qian, WANG Tianxiu, GAO Hui, HUANG Yuanyi, LUO Deyang
. Analysis and Control of Hybrid Powertrain Cooing Sound[J]. Vehicle Engine, 2025
, 0(3)
: 32
-39
.
DOI: 10.3969/j.issn.1001-2222.2025.03.005
