Strategy for controlling ratio changes in a swap-shift automatic transmission
US6370463B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 1, 2001 |
| Grant date | Apr 9, 2002 |
| Priority date | — |
| Expiry date | Nov 1, 2021 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2200/201
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A method for controlling ratio changes in a swap-shift transmission having a first simple planetary gear unit and a second compound planetary gear unit, the two gear units being arranged in series disposition, pressure-operated friction elements for separately braking the reaction member at each of the gear units to establish a change in ratio. The change in ratio consists of a downshift by releasing a reaction friction element for the first gear unit and upshifting the second gear unit by applying a second friction element to anchor a reaction member of the second gear unit in a non-synchronous fashion to achieve a consistent shift quality without precise matching of friction element application and release whereby inertia torque disturbances in the torque output elements of the transmission are avoided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.