| 摘要 |
<p>An electromechanical VVA system for controlling the poppet valves (5) in the cylinder head of an internal combustion engine. The system varies valve lift, duration, and phasing in a dependent manner for one or more banks of engine valves. A rocker subassembly for each valve (5) is pivotably disposed in roller bearings on a rocker pivot shaft (609) between the camshaft (2) and a roller follower. A control shaft (625) supports the rocker pivot shaft (609) for controlling a plurality of rocker subassemblies mounted in roller bearings for a plurality of engine cylinders. The control shaft (625) rotates about its axis to displace the rocker pivot shaft (609) and change the angular relationship of the rocker subassembly to the camshaft (2), thus changing the valve opening, closing, lift and duration. An actuator (892) attached to the control shaft (604) includes a worm gear drive for positively rotating the control shaft (625).</p> |
