| 摘要 |
<p>A scroll type fluid displacement apparatus includes a pair of scrolls each having a circular end plate from which a spiral element extends. Both spiral elements interfit at an angular and radial offset to make a plurality of line contacts to define at least one pair of sealed off fluid pockets. One scroll, the orbiting scroll, is operatively connected to a driving mechanism and a rotation preventing mechanism, such as a ball coupling device, to effect orbital motion thereof. As the orbiting scroll orbits, the sealed off fluid pockets move along the shifting line contacts of the spiral elements to change the volume of the fluid pockets. According to the present invention, the number of turns of the orbiting and fixed spiral elements are different so that these spiral elements are of different length. As a result, the gas pressure distribution within the fluid pockets is asymmetrical which results in a larger moment of rotation for the orbiting scroll. This larger moment of rotation acts on the balls of the ball coupling device to prevent vibration and reduce noise.</p> |
