| 摘要 |
A cover 222 for a drive assembly of an internal combustion engine, at least partially defining a chamber 224 for accommodating the drive assembly, comprising two or more acoustic resonators arranged to be in fluidic communication with the chamber, wherein first and second resonators 230, 250 are provided in series, the second resonator being in fluidic communication with the chamber via the first resonator. At least a portion of at least one of the resonators may be provided inside or outside of the chamber. The first and second resonators may be tuned so as to dampen oscillations with first and second frequencies respectively. At least one of the resonators may be formed by one or more reinforcing ribs 226 provided on a wall of the cover. Preferably the resonators comprise a cavity 232 and an opening 234 with a neck portion 236 extending from the opening and into the cavity. The cover reduces the noise emitted between the crankshaft and camshaft of the drive assembly. |
