Compact centrifugal blower with annular stator
AssigneeRobert Bosch GmbH
InventorThomas Chapman
Life of this patent
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Abstract
This invention is characterized by a very compact blower assembly architecture designed to operate at low Reynolds numbers. The assembly includes an impeller with forward-curved blades and a hub that is shaped to minimize the overall package volume of the assembly. The impeller is driven by a low-power, brushed, direct-current motor. A shroud part includes a generally cylindrical inlet that directs the air into the impeller, and a surface that forces the air leaving the impeller to turn from a generally radial and tangential direction to a generally axial and tangential direction. The shroud part directs the air into a single stage of stator blades that reduces the tangential component of the air velocity and produces a static pressure rise.
Claims10
A centrifugal blower assembly comprising an impeller, a stator, a shroud
- and a motor;
- said impeller comprising impeller blades and an impeller hub and being driven by said motor, said shroud comprising an inlet for the impeller;
- said stator and shroud functioning together to guide airflow exiting the impeller, to turn the airflow from a generally radial and tangential direction to a generally axial and tangential direction, and to guide the airflow through a set of stator blades;
- said centrifugal blower assembly being further characterized by:
- a) said impeller blades being forward-curved;
- b) said impeller hub covering at least 30% of the axial extent of the motor;
- c) said stator comprising a single stage of stator blades within an annular flow passage;
- d) said stator blades having a chord length at least 15% of the stator blade diameter;
- e) said stator having a blade diameter of no more than 150 millimeters;
- and
- f) said motor having a power input of less than 25 watts.
A centrifugal blower assembly comprising an impeller, a stator, a shroud and a motor;
- said impeller comprising impeller blades and an impeller hub and being driven by said motor, said shroud comprising an inlet for the impeller;
- said stator and shroud functioning together to guide airflow exiting the impeller, to turn the airflow from a generally radial and tangential direction to a generally axial and tangential direction, and to guide the airflow through a set of stator blades;
- said centrifugal blower assembly being further characterized by:
- a) said impeller blades being forward-curved;
- b) said impeller hub covering at least 30% of the axial extent of the motor;
- c) said stator comprising a single stage of stator blades within an annular flow passage;
- d) said stator blades having a chord length at least 20% of the stator blade diameter;
- e) said a stator having a blade diameter of no more than 90 millimeters;
- f) said motor being a direct-current brushed motor with a power input of less than 5 watts;
- g) said stator comprising features to hold said motor in position without the use of additional fasteners;
- h) said impeller, said stator, and said shroud being constructed from injection molded plastic;
- and
- i) said blower assembly being sized and designed for cooling electronic components positioned in the engine compartment of a vehicle.
Dependencies are inferred from the claim text.