摘要 |
<p>An intake manifold (18) for an engine (10) includes a Roots-type supercharger (26) having a torsion damping mechanism (54) for reducing audible rattle of timing gears (72,74) which prevents contact of meshed lobes (28a,29a) of the supercharger rotors (28,29). The damping mechanism includes torsion springs (98,100) preloaded against each other. Torsion spring (98) has a low spring rate for attenuating torque fluctions or spikes during non-supercharging, low engine speed modes of operation. Spring (100) has a relatively high spring rate and functions as a shock absorber during engine shut down and during rough engine operation.</p> |