Transmission & Driveline Mechanics

FEV offers comprehensive transmission development resources, CAE and testing activities for the development and troubleshooting of a variety of transmission types. This development activity comprises:

Driveline and Shaft Component CAE

• 1D Driveline layout / vehicle simulation
• 3D Driveline dynamic vibration / resonance
• Dynamic operation and abuse loads
• Specific and unique dynamic gear stress and lifetime simulation (Contact surface-based differential simulation technique)
• Stresses and HCF/durability and lifetime of shafts, bearings, joints/links

Powertrain Housing Assembly / Brackets

• Stresses and deformation under assembly and operational loads
• High cycle fatigue
• Bearing gutter alignment
• Tightness / sealing
• Bolt pattern layout and optimization

Inner and Outer Gear Shift Mechanism

• Shift mechanism durability (shift fork and joints)
• Shift efficiency
• Shift force characteristic / synchronizing simulation

Automatic Structure Optimization

• Linear topology optimization
• Nonlinear shape optimization considering thermo-mechanical load history

Functionality and Durability Testing

• Oil-level / oil distribution test
• Oil / bearing temperature measurement
• Synchronization and inner shift mechanism test
• Shift force measurement
• Static / dynamic tooth backlash test
• Gear load measurement and tooth contact pattern test
• Dynamic driveline vibration / resonance test
• Power dissipation / efficiency measurement
• Structure vibration test
• Typical vehicle load cycle measurement
• Overload / abuse test
• Durability tests (dynamometer and fired powertrain)

One of the most challenging tasks presented during transmission development is the gear and tooth profile layout. This profile layout is based on the appropriate lifetime and minimized parameter excitation during the overall lifetime of the transmission. To handle these tasks and balancing the opposing requirements, FEV developed a new differential simulation technique describing each pair of gears in contact with local flank topology and mechanical properties within a Multi-body Analysis (MBS) environment. The engaging and disengaging procedure, combined with the local tooth load under dynamic operation conditions are simulated with a high degree of accuracy. The detailed description of the flank topology, including profile corrections and deviations, provides an accurate parameter excitation characteristic and the possibility to optimize the tooth surface topology for minimizing excitation and tooth load. In principal, each load and speed would require a specific flank topology. The optimization can be effectively completed for all operating conditions. FEV has the capability to efficiently predict and optimize several measurements (flank topology, gear tooth/body forces and accelerations) of new and worn gear sets.