Blower
There is provided a blower realizing characteristics in which the pressure is reduced as the flow rate is increased in pressure-flow rate characteristics in a case where an impeller rotates at a fixed rotation speed, while having a simple structure. An impeller includes a main plate formed in a disc shape and a plurality of main blades formed to stand on the main plate, the impeller is extended to a position facing the inside of a discharge flow path formed so as to circle on an outer peripheral side, and auxiliary blades are formed to stand on an extended portion extended inside the discharge flow path.
1. A blower in which an impeller and a motor driving the impeller to rotate are housed in housings, and outside air is sucked from an intake port provided at a central part in the housings in an axial direction by rotation of the impeller and is discharged from a discharge port of a discharge flow path scrolling on an outer side in a radial direction,
wherein the impeller includes a main plate formed in a disc shape, and a plurality of main blades and auxiliary blades,
the main blades are formed to stand on one surface of the main plate and
the auxiliary blades are formed to stand on another surface of the main plate and extend from a vicinity of a shaft hole to a position located in an outer peripheral edge portion of the main plate, wherein the auxiliary blades face an inside of the discharge flow path,
the impeller extends to a position facing the discharge flow path, which is formed in an annular shape and arranged thereunder in the axial direction on the outer peripheral side thereof,
the auxiliary blades include both long blades and short blades which are alternately arranged around the impeller in the circumferential direction,
the long blades extend from a vicinity of the rotor shaft hole in the central portion to an outer peripheral edge portion to a position facing the discharge flow path, wherein the long blades face the inside of the discharge flow path, and the short blades extend from a middle part of the main plate in the radial direction to the outer peripheral edge portion, and
respective standing end surfaces of the auxiliary blades are connected in the circumferential direction to integrally form an auxiliary blade shroud.
2. The blower according to claim 1 , wherein an outer peripheral edge portion of the main plate is formed to be curved toward the inside of the discharge flow path.
3. The blower according to claim 1 , wherein the auxiliary blades are formed on both of the main plate and the main blade shroud.
4. The blower according to claim 1 , wherein a housing-side auxiliary shroud fixed to the housings is formed at a position facing the auxiliary blades inside the discharge flow path provided in the housings.