Forward skewed multi-blade impeller with narrow cavity and integral casting technique thereof

The invention relates to a forward skewed multi-blade impeller with a narrow cavity, which is used for a centrifugal fan and is low in noise, and an integral casting technique thereof. The impeller comprises a base plate and a hollow front plate, and narrow blades are installed along the circumference between the base plate and the front plate. The difference lies in that the blades are arc-shaped; the radial length of each blade is 20mm-30mm; the outlet height H of the meridian plane of each blade is 10mm-20mm; the number of the blades distributed along the circumference is 20-60; and the whole impeller is integrally cast. The impeller is compact in structure, low in noise, light in weight, high in structural strength and simple and convenient in maintenance. By adopting a moveable blademold structure to fabricate an impeller inner core blank removing mold so as to finish the integral casting of the impeller, the invention solves the technical problem of blank removal failure of a closed impeller with a narrow cavity and has the advantages of high casting precision and good quality of the impeller, low casting cost and high production efficiency. The technique is widely applicable for integral casting of various multi-blade impellers, with the effect obviously better than that of similar products.