Calibration method for transmission control clutches
US5224577A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 9, 1992 |
| Grant date | Jul 6, 1993 |
| Priority date | — |
| Expiry date | Jul 9, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T74/1926
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
The hydraulically operated brake and clutch elements (controlled by proportional control valves) of a vehicle powershift transmission have fill pressures which are calibrated by a method wherein the output shaft of the transmission is disconnected from the vehicle drive shaft so that the transmission output shaft is free to rotate and certain ones of the plurality of the control elements other than the control element being calibrated are fully pressurized in order to prevent rotation of a part of the control element being calibrated. The engine is run at a predetermined speed and the pressure applied to the control element being calibrated is gradually increased while engine speed is monitored. When the monitored engine speed changes by predetermined amount, a value is saved corresponding to the calibration pressure. The transmission is automatically shifted to neutral if vehicle motion is sensed. The volume of hydraulic fluid required to initially engage the control element may be calibrated in a similar manner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.