The design and calibration of conventional 3- or 4 speed automatic transmission control systems is carried out in most cases according to static hydraulic aspects. These systems work digital by opening or closing "YES/NO" type shift valves to change the ratio. Continuously variable transmissions (CVT) need a control system that continuously changes the ratio by regulating a "ratio control valve". Due to the complex structure and closed loops incorporated in CVT hydraulic control system, there is an increasing demand on adequate development aids like computer simulation systems. Especially for intensive analysis of the dynamic behaviour and determination of influencing parameters such an engineering tool can be very helpful. The objective of this presentation is to show the application of a computer program system that describes the dynamic behaviour of a CVT hydraulic control system and the potential improvements of this system by means of simulation. For the purpose of demonstration, the hydraulic control system of a Ford CVT, called CTX, using the Van Doorne's steel belt principle, will be discussed. The used computer program DSH was developed by the "Institute for Hydraulic and Pneumatic (IHP)" of the Technical Highschool Aachen.

Media Info

  • Features: Figures;
  • Pagination: p. 51-70

Subject/Index Terms

Filing Info

  • Accession Number: 00399881
  • Record Type: Publication
  • Source Agency: National Highway Traffic Safety Administration
  • Report/Paper Numbers: ISATA 84004, HS-038 422
  • Files: HSL, USDOT
  • Created Date: Oct 31 1985 12:00AM