Patent · US Expired

Error recognition process for automatic gear boxes transmission

US6081760A · kind A · utility

6Cited by

4References

2Claims

0Family size

Assignee

ZF FRIEDRICHSHAFEN AG · DE

Inventors

Ralf Dreibholz · Meckenbeuren, DE
Gerd Frotscher · Friedrichshafen, DE
Kai Staiger · Friedrichshafen, DE

Key dates

Filing date	Jan 9, 1998
Grant date	Jun 27, 2000
Priority date	—
Expiry date	Jan 9, 2018

Classification

Technology area (CPC F)Mechanical Engineering; Lighting; Heating
CPC primaryF16H2061/1276
WIPO fieldMechanical elements
WIPO sectorMechanical engineering

Abstract

The invention concerns a method of monitoring the gearshift process in an automatic transmission. In order to be able to recognize fault conditions, the invention proposes in one embodiment that the actual change in transmission ratio is compared with a required change in transmission ratio. In another embodiment the change in the difference in the speed of the rotation of the engaging shift element is examined. It is also possible to analyze the gradient of the difference in the speed of rotation of the engaging shift element. A further possibility is to monitor the gradient of the transmission input speed. In addition, the gradient of the speed at the transmission output can be monitored. As result of the analysis, the transmission ratio is either retained or a predetermined safety condition is brought about.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.