Abstract: Modular and Scalable Layshaft Transmission Design
For today’s worldwide applications, scalability of transmissions has a vertical as well as a horizontal dimension. Getrag pursues several modular and scalable design approaches that reflect typical market and OEM requirements.
- Dr-Ing. Jörg Willert, Director Central Core Engineering, GETRAG, Magna Powertrain
- Dr-Ing. Carsten Bünder, Senior Manager Product Engineering, GETRAG, Magna Powertrain
Not too long ago, transmissions were mostly closed solutions with little potential for being adapted to different applications. The major concern was to design a universal product that enables largest possible economies of scale with the whole transmission. Currently, the boundary conditions for transmission development are significantly changing, Figure 1. Many vehicles are intended for different global use cases, resulting in much more complex and diverse requirement profiles. Efficient Transmission designs should on one hand enable large production numbers, on the other hand be suitable for different performance levels and market-specific requirements. After all, future fleet consumption and CO2 regulations do not allow any compromises with regard to package, weight and efficiency.
These new requirements lead to a new understanding of modularity, where a universal “closed system” would be replaced by a functionally scalable system, while maintaining economies of scale. The task is to resolve this seeming contradiction.
Benefits of Modularity and Scalability
Generally spoken, the requirements for modular and scalable transmissions are economies of scale of whole transmissions and functional components as well as scalability for market-specific functions, different performance levels and improved quality assurance.
In practice, these requirements often correlate. Functional modules are on one hand necessary to enable economies of scale. For example, these can be shift and clutch actuation modules that are used across a whole family of transmissions. On the other hand, functional modules can be the basis for scaling market specific features or product performance. The latter is for example represented by scalable e-machines, which allow for mild, full or plug-in hybrids within the same base transmission. Another advantage of defining functional modules is enhanced quality assurance: The more integrated components can be used across different transmissions, the easier it is to control quality and to transfer improvements or even new generations of functional modules to every application affected.
Generally spoken, the intrinsic high efficiency of layshaft transmissions, plus the high potential to define functional modules, Figure 2, allows for efficient products with high economies of scale and functional scalability. This applies for MTs as well as for AMTs and DCTs as well as their hybrid derivate.
Dr-Ing. Jörg Willert, Director Central Core Engineering GETRAG, Magna Powertrain
Dr-Ing. Carsten Bünder, Senior Manager Product Engineering, GETRAG, Magna Powertrain