| 摘要 |
A bypass type vacuum includes a casing constructed of a cover and a motor housing disposed within the cover. A first circular partition of the motor housing defines a main expansion chamber which receives working air that is driven radially through side openings in a fan housing that surrounds a fan impeller and is disposed within the main chamber in a decidedly off-center position. A second circular partition of the cover surrounds the first partition and cooperates therewith to define a ring-like auxiliary chamber having an entrance opening in the first partition and an outlet in the second partition. Diametrically opposed constrictions provided by hand grip formations divide the auxiliary chamber into first and second sections of generally equal length, with the entrance being at the center of the first section and the outlet being at the center of the second section, the entrance also being at the portion of the first partition that is closest to the fan housing. Working air generated by the impeller flows from side openings of the fan housing into the main chamber and exits therefrom through the entrance into the first section where the working air splits and flows in opposite directions through the constrictions into the second section through opposite ends thereof, finally exiting through the outlet. |
