Aspects of Vehicle-Focused Powertrain NVH Development
Powertrain sound quality is an essential feature for today’s automotive customers. It is influenced by powertrain noise and vibration (“source”) as well as airborne and structureborne noise (“path”). Often it is difficult to separate source and path on overall vehicle sound quality.
Real World 3-Element Screening Test for Continuously Variable Transmission Lubricant Applications
Lubricant technology can enable optimized CVT efficiency by providing the appropriate viscosity for pump operation along with the right amount of friction for the variator systems. By increasing the friction at the belt-pulley contact the pulley clamping force can be reduced, thus also reducing the tensile stresses on push belt bands.
Potential and Further Development of the Free Spinning Friction Ring
Requirements for new transmissions comprise higher power density, high overall efficiency, low total cost of ownership and improved shift quality.
Adaptive AWD System for Improved Efficiency and Vehicle Dynamics
All-wheel drive vehicles offer benefits like better mobility, vehicle safety and handling behavior, leading to an increasing customer demand worldwide. On the other hand, AWD to some extent means higher weight ratios and more rotating components, both resulting in lower efficiency.
NVH Technology Developments in Push Belt CVTs
The sound behavior of pushbelt CVTs changes during operation depending on a number of criteria like transmission ratio, pressure etc. Bosch Transmission Technology B.V. has performed a study to optimize the noise performance for future requirements.
Transmission Ghost Noise from Gears and Bearings
At the 9th international transmission Symposium USA, Dr. Scott Yu, Transmission NVH Technical Specialist, is talking about transmission ghost noise from gears or bearings.
A Schaeffler One-way Clutch to Meet Future Powertrain Needs
The demand for one-way clutches in planetary automatic transmissions continues with today’s modern architectures. There is a need for lower drag torque during freewheeling and a need to decrease mass, inertia and package space. There is even a need for a clutch that can freewheel in both directions or neither direction.
CVT as a Versatile Carrier for Multiple Hybridization Levels
Running the powertrain on its best operating points can be achieved best by CVT functionality. Pulley-belt type CVT has been the most affordable and widely adopted technology to date. CVTs also reduce the influence and sensitivity of drive cycle dynamics on fuel economy.