| 摘要 |
A camshaft 101 for an engine comprises a first cam 103 to control a first cylinder valve and a second cam 105 to control a second cylinder valve of the same cylinder, the valves being both inlet valves or both outlet valves and the profiles (107, 109, figs 1b,1c) of the cams 103, 105 differing in shape, size or angular orientation. The cams 103, 105 may have different base circle diameters, overall heights, lobe angles, nose radii, dwell angles, opening ramps, closing ramps, opening flanks and/or closing flanks. The valves thus have different amounts of lift, different opening periods or different timings which may determine the swirl pattern. The first and second valves may differ in diameter. The first and second valves may be selectively deactivatable. |
