Alexander Neubauer | Daimler AG | 09 October 2014
4
2.1 Methodology for NVH-Simulation of DCT Gearbox
SIMPACK- Pre

SIMPACK-Post
• flexible gearbox housing • modal materialdamping • external nodes for evaluation of
Unloaded gears
Idle speed
Coast / Full load
Rattling
source/reason: • Impulsive hits at the gear backlash limits • Loose gear oscillation of unloaded gearwheels
Big models, Low Discretisation
Low frequency range
Vortrag Alexander Neubauer | DAIMLER AG, RD/FNP | 01.10.2014
Compact models, High Discretisation
High frequency range
Content of presentation
1. Gearbox Simulation in Driveline Developement 2. Overview Testrigmodels for NVH-Simulation and Methodology 3. Simulation of Gearwhining in the DCT Gearbox 4. Evaluation of Rattling Sensitivity of DCT Gearbox 5. Conclusion and Future Work
3
1.2 Overview of Noises in Automotive Gearboxes
Gearbox Noises
Loaded gears
Gear whining
source/reason: • Fluctuation in stiffness (transmission error) • Macrogeometry of gear (Spur bevel- and
KS2 X
20
10
0
-10
-20
570 Hz
1600 min-1
-30
1500
2000
Drehzahl
[1/min]
21
KS1 Z
3500
3000
2500
2000
1500
1000 0
1000
2000
•
•
•
940 Hz 2700 min-1
2500
3000
Drehzahl [1/min]
42
• Beschleunigung [dB/(m/s²)] 20
Simulation Methods for NVH-Development of a Double Clutch Transmission Gearbox
SIMPACK User Meeting 2014
Alexander Neubauer Mercedes-Benz Cars Development Daimler AG, Stuttgart
macro- and microgeometry • gearwheels with material data • analytical gearpair contact
simulation (ISO 6336)
• Taper roller bearings with stiffness in 3D-Map from the supplier (BEARINX-MAP)
• bearing properties from KISSSOFT interface (input from CAD)
• transmission error • eigenfrequency analysis • Detailled analysis of mechanism
Beschleunigung [dB/(m/s²)] 30
63
10
•0
-10
-20
-30
Helix Gearwheel) • Microgeometry (Gearteeth flank correction) • High loadtorque (Pretension) • Bending stiffness of the shafts • Structural behavior of housing • Oil viscosity and temperature
(also synchrobodies) because of gear backlash • Torsional vibration excitation of the driven gear • Angular acceleration amplitude is responsible
for taking off loose gear from the driven flank of the fix gear • Oil viscosity and temperature
Alexander Neubauer | Daimler AG | 09 October 2014
2
1.1 Driveline Development - NVH Simulation
Design
Integration
Design Matching
3
Simulationmodels - Design and Developement Driveline
structure borne sound • rigid body elements for
gearshaft mounting
• flexible gearshafts • switchable gears • bearings with 6 DOF • syncrobodies as dummy bodies • rigid gearwheels with detailed