Variable camshaft timing system
US4878461A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1988 |
| Grant date | Nov 7, 1989 |
| Priority date | — |
| Expiry date | Jun 30, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S474/90
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A variable camshaft timing system for an internal combustion engine varies the relative angular position between the intake camshaft and the exhaust camshaft by controlling the path of the timing belt means. A first belt means is interconnected at one end of the engine between the crankshaft and the exhaust camshaft. At the other end of the engine the intake camshaft and the exhaust camshaft are connected by a second belt means for rotating the intake camshaft from the rotational drive supplied via exhaust camshaft. Idler arms are positioned for controlling the path and tension in the second belt means for varying the timing of the intake camshaft relative to the exhaust camshaft. A motor means operates to position the idler arms through a positioning cam means. The motor is controlled from an electronic control unit which receives signals indicating the engine operating characteristics and through a look-up table steps the positioning cam means to pivot the idler arms to rotate the intake camshaft relative to the exhaust camshaft thereby changing the intake valve timing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.