Search Results

The object of this paper titled “Electronic Shift for Automatic Transmissions” (ESAT), is to describe the latest developments in remote vehicle shifting systems or shift-by-wire for passenger vehicles and light trucks. Also, included in this paper is a description of the system, hardware and software development, testing and vehicle installations. The ESAT system, with its 2 or 3 module concept, provides packaging flexibility and offers the interior designer complete freedom for ergonomic styling. The system prevents the occurrence of shift linkage “PRNDL” misalignment in that it is pre-adjusted. It also improves transmission reliability by providing enhanced features such as; ‘automatic cycle to park’, ‘shift lock’, and ‘speed lockouts’.

Traditionally manual clutch actuation for automobiles was a spinoff from hydraulic brake technology namely heavy steel or cast iron cylinders, steel pipes and rubber hoses. Because of this archaic, inefficient and expensive approach to providing a mechanical advantage, an alternative lower cost system of cable operation gained popularity throughout the industry. However, the 1:1 ratio of a cable plus routing problems, NVH issues, efficiency losses and the need for complex adjustment mechanisms, opened up the opportunity for a rebirth of the old hydraulic concept. The goal was to design a system with a totally new approach that would meet the following criteria: High efficiency, increased temperature resistance, increased durability, reduced package size and weight, cost competitive with cable systems, and finally to take advantage of the latest advances in materials and processes.