Abstract: Acceptable automatic shifting – with all benefits of a manual transmission

Abstract: Acceptable automatic shifting – with all benefits of a manual transmission

A New Automatic Transmission Approach – a Suitable MT Replacement?

Driver’s comfort and safety, reduced fuel-consumption and emission as environment requirements and the wish of connectivity are demanding automatic shifting transmissions. Solutions are known: AT, DCT, … not suitable to replace a MT – being cheap, simple, robust, producible anywhere with common production technology – new, even unusual ideas are needed!

  • Günther Priwitzer, Chief Engineer Driveline and Transmission System, Ricardo Deutschland

Requirements

On one side we can see a clear demand / wish for an automatic shifting transmission. From legal side for emission (efficiency powertrain, base for more gears and higher spread), from driver side for fuel consumption and comfort with high expectations for shift performance. We still had a similar approach with an AMT as “cheap” solution but this was not accepted by the end user because of long shift-times and long torque interruption and cost as well.

On the other side automotive products need to fulfill strong commercial demands. The MT still is the cheapest existing transmission type. Even a „cheap“ AMT nearly doubles the costs for the vehicle. AT and DCT approximately triple costs. And last but not least nobody can ignore the demand of emerging nations to produce, maintain and repair these automotive products local. The general need of a cheap and robust vehicle as entrance to a “mobile” life will be valid for the next decades. Technology should be able to create a competitive “automised” solution for cleaner and more comfortable vehicles to replace the MT (also light trucks for distribution function can benefit) – creating new ideas, using new ways and unusual thinking.

Targets

  • No on-costs for the vehicle compared with a MT solution
  • Producible with common MT production technology
  • Mechanical efficiency equal or better than a comparable MT solution
  • Automatic shifting with an acceptable shift performance – short shift time, no or short torque interruption, smooth shifts
  • optimised power train efficiency equal or better than a comparable dry DCT solution

Günther Priwitzer, Chief Engineer Driveline and Transmission System Ricardo Deutschland