Blower

Abstract

A blower includes a casing having an air inlet, an electric motor having a rotor and a stator, an impeller driven by the motor, and a diffuser for directing air from the impeller. The impeller and the diffuser are received in the casing. The impeller has a base and blades supported by the base. The diffuser has a plate like portion with diffuser vanes surrounding the impeller. Inlet angles of the impeller blades is between 20˜30 degrees and outlet angles of the impeller blades is between 26˜38 degrees.

1 . A blower comprising: a casing having an air inlet, an electric motor having a rotor and a stator, an impeller driven by the motor, and a diffuser for directing air from the impeller, the impeller and the diffuser being received in the casing, the impeller having a base and blades supported by the base, the diffuser having a plate like portion with diffuser vanes surrounding the impeller, wherein an inlet angle of the impeller blades is between 20˜30 degrees and an outlet angle of the impeller blades is between 26˜38 degrees. 
     
     
         2 . The blower of  claim 1 , wherein an inlet angle of the diffuser vanes is between 7˜115 degrees. 
     
     
         3 . The blower of  claim 1 , wherein an outlet angle of the diffuser vanes is between 15˜17.5 degrees. 
     
     
         3 . The blower of  claim 2 , wherein an outlet angle of the diffuser vanes is between 15˜17.5 degrees. 
     
     
         4 . The blower of  claim 1 , wherein the rotor comprises: a shaft, a rotor core fixed on the shaft, a commutator fixed on the shaft adjacent the rotor core, and rotor windings wound about poles of the rotor core and electrically connected to the commutator,
 wherein the stator comprises: an axially extending housing, at least one permanent magnet fixed to the inner surface of the housing, electrical terminals, and at least one pair of brushes for making sliding contact with the commutator, and   wherein the motor is operable by applying LVDC power to the rotor windings via the commutator.   
     
     
         5 . The blower of  claim 4 , wherein the stator has two magnetic poles, the rotor core has 5 slots, and the commutator has 5 commutator segments. 
     
     
         6 . The blower of  claim 4 , wherein the housing has an outer diameter of 35.7 mm±3%, the rotor core has an axial length of 25.1 mm±3%, and the permanent magnet has a thickness of 4.9 mm±3%. 
     
     
         7 . The blower of  claim 1 , wherein the casing has an outer diameter of 95 mm±3% 
     
     
         8 . The blower of  claim 1 , wherein the rotor is configured to rotate at a speed between 18,000˜22,000 rpm. 
     
     
         9 . The blower of  claim 1 , wherein the diffuser further comprises return guide vanes formed on one surface thereof remote from the impeller. 
     
     
         10 . A blower comprising: a casing having an air inlet, an electric motor having a rotor and a stator, an impeller driven by the motor, and a diffuser for directing air from the impeller, the impeller and the diffuser being received in the casing, the impeller having a base and blades supported by the base, the diffuser having a plate like portion with diffuser vanes surrounding the impeller, wherein an inlet angle of the diffuser vanes is between 7˜11.5 degrees and an outlet angle of the diffuser vanes is between 15˜17.5 degrees. 
     
     
         11 . A blower comprising: a casing having an air inlet, a low voltage direct current electric motor, an impeller driven by the motor, and a diffuser for directing air from the impeller,
 wherein the casing has an outer diameter of 95 mm±3% and accommodates the impeller and the diffuser;   wherein the impeller has a base, a cover and blades supported between the base and the cover, an inlet angle of the impeller blades being between 20˜30 degrees and an outlet angle of the impeller blades being between 26˜38 degrees;   wherein the diffuser has a plate like portion with diffuser vanes surrounding the impeller and return guide vanes formed on a surface of the plate like portion remote from the impeller, an inlet angle of the diffuser vanes being between 7˜11.5 degrees and an outlet angle of the diffuser vanes being between 15˜17.5 degrees;   wherein the motor comprises: a two pole permanent magnet stator having at least one permanent magnet with a thickness of 4.9 mm±3% and a housing accommodating the at least one permanent magnet and having an outer diameter of 35.7 mm±3%; and a wound rotor disposed within the stator, the rotor having a five slot rotor core with an axial length of 25.1 mm±3% and a five segment commutator, the motor being configured to operate on an electrical power supply having a voltage between 12 and 24 volts and to rotate at a speed between 18,000˜22,000 rpm.