Method and apparatus for preventing hunting between ranges in a continuously variable transmission
US6409628B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 29, 2000 |
| Grant date | Jun 25, 2002 |
| Priority date | — |
| Expiry date | Sep 29, 2020 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2037/0886
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A transmission assembly is disclosed. The transmission assembly includes a continuously variable transmission driven by an input shaft at an input speed, a mechanical transmission coupled to the continuously variable transmission for selecting a first gear range and a second gear range, an output shaft driven by the mechanical transmission at an output speed, and controller operable to receive a speed command and generate a transmission ratio is command which control a ratio of the output speed to the input speed, and generate a shift command which causes the mechanical transmission to shift from the first gear range to the second gear range. An upper transmission ratio limit defined by an engine lug limit. A lower transmission ratio limit is defined by an engine overspeed limit. The controller causes the transmission to execute a shift from the first gear range to the second gear range which causes an instantaneous change in output speed. The engine lug limit or the engine overspeed limit are adjusted to inhibit a subsequent shift from the second gear range to the first gear range. A method for controlling a transmission assembly is also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.