Patent ID: 8747071
Filing Date: 2014-06-10
Classification: F04D

Abstract:
1. A drain pump for an indoor unit of an air-conditioner comprising: a motor; a rotary impeller connected to an output shaft of the motor; and a housing that includes an inlet formed at a lower end portion thereof and an outlet formed at a side portion thereof, the rotary impeller being rotatably received in the housing, wherein the rotary impeller includes a shaft portion connected to the output shaft of the motor, a plurality of plate-like large-diameter blades that extends from the shaft portion in a radial direction, a plurality of plate-like small-diameter blades connected to lower edge portions of the large-diameter blades and is received in the inlet, and a ring member connected to outer peripheral portions of the large-diameter blades, each of the large-diameter blades is divided into an inner blade that extends outward from the shaft portion with a leading end thereof being separated from the ring member, and a corresponding outer blade that extends inward from the ring member with a leading end thereof being separated from the shaft portion, and the inner and outer blades of the large-diameter blades are alternately disposed around the shaft portion, the rotary impeller further includes plate-like auxiliary blades, which extend in the radial direction, between the large-diameter blades that are adjacent to each other in a circumferential direction of the shaft portion, each of the auxiliary blades is divided into an inner auxiliary blade that extends in the radial direction between the shaft portion and the ring member, and an outer auxiliary blade that extends inward from the ring member, and the inner blades and the inner auxiliary blades, and the outer blades and the outer auxiliary blades are alternately disposed around the shaft portion, each auxiliary blade is disposed between two adjacent large-diameter blades, and each outer blade of the large-diameter blade is arranged, with respect to the corresponding inner blade of the large-diameter blade, at a position displaced around the shaft portion by ½ of the angle between the inner blade of the large-diameter blade and the inner auxiliary blade adjacent thereto in the circumferential direction of the shaft portion.