| 摘要 |
Apparatus and methods for varying valve lift in an internal combustion engine are disclosed. The apparatus include a rocker arm having an elongate aperture and a shaft configured to pass through the aperture. The height of the shaft with respect to the aperture is variable to effect different rocker arm ratios when in combination with a fixed fulcrum point. When the shaft is located in a lower position with respect to the aperture in the rocker arm, the rocker arm pivots around the rocker arm shaft producing full valve lift. Alternatively, when the rocker arm shaft is positioned at a height above the lower position, an upper surface of the rocker arm becomes engageable to varying degrees with the fixed fulcrum point, allowing the rocker arm to pivot around the fixed fulcrum point, thereby reducing the rocker arm ratio, and corresponding valve lift dependent on the rocker arm shaft position. Corresponding methods are also disclosed.
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