Electric blower

Patent metadata

Field	Value
Publication number	US-9810239-B2
Application number	US-201514747307-A
Country	US
Kind code	B2
Filing date	Jun 23, 2015
Priority date	Jul 31, 2014
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

An electric blower includes a centrifugal impeller, a diffuser including stationary vanes on a discharge side of the centrifugal impeller, a motor configured to drive the centrifugal impeller, a fan case configured to cover the centrifugal impeller and the diffuser, a housing case joined to the fan case, and return guide vanes that guide air which has been guided by the stationary vanes to an inner surface of the fan case radially inward through a space under the diffuser. The housing case includes an annular lower plate portion located axially below the diffuser. Each return guide vane is continuous with an upper surface of the annular lower plate portion. An upper end of each return guide vane is located axially opposite to the diffuser.

First claim

What is claimed is:

1. An electric blower comprising:
a centrifugal impeller that rotates about a central axis extending in a vertical direction;
a diffuser including a plurality of stationary vanes located on a radially outer side of the centrifugal impeller;
a motor that drives the centrifugal impeller;
a fan case that covers the centrifugal impeller and the diffuser, and including an inlet port located axially opposite to a central portion of an upper surface of the centrifugal impeller;
a housing case located radially outside of the motor, and joined to the fan case; and
a plurality of return guide vanes each of which guides air which has been guided by each of the plurality of stationary vanes of the diffuser to an inner surface of the fan case radially inward through a space under the diffuser; wherein
the housing case includes an annular lower plate portion located axially below the diffuser;
each of the plurality of return guide vanes is continuous with an upper surface of the annular lower plate portion;
an upper end of each of the plurality of return guide vanes is located axially opposite to the diffuser; and
at least a partial portion of each of the plurality of the return guide vanes are axially aligned with the plurality of stationary vanes in the vertical direction.

2. The electric blower according to claim 1 , wherein an inner circumferential portion of each of the plurality of return guide vanes extends up to a position radially inward of an inner end of the annular lower plate portion.

3. The electric blower according to claim 2 , wherein
the housing case further includes a tubular portion at an inner circumferential portion of the annular lower plate portion to define an exhaust passage between the tubular portion and an outside of the motor; and
each of the plurality of return guide vanes includes a portion extending between an inner circumferential surface of the tubular portion and the outside of the motor.

4. electric blower according to claim 3 , wherein a junction of the annular lower plate portion and the tubular portion of the housing case includes a smoothly curved inner surface.

5. The electric blower according to claim 4 , further comprising flow control vanes each of which is positioned between adjacent ones of the return guide vanes between the inner circumferential surface of the tubular portion and an outer circumferential surface of the motor.

6. The electric blower according to claim 1 , wherein
the housing case further includes a tubular portion located at an inner circumferential portion of the annular lower plate portion to define an exhaust passage between the tubular portion and an outside of the motor; and
each of the plurality of return guide vanes includes a portion extending between an inner circumferential surface of the tubular portion and the outside of the motor.

7. The electric blower according to claim 6 , wherein a junction of the annular lower plate portion and the tubular portion of the housing case includes a smoothly curved inner surface.

8. The electric blower according to claim 6 , wherein the diffuser further includes an annular inner wall portion located radially inside of the return guide vanes, and including a curved circumferential surface that guides, to the exhaust passage, air which has been guided radially inward by each return guide vane.

9. The electric blower according to claim 6 , wherein
the diffuser further includes an annular inner wall portion located radially inside of the return guide vanes, and including a curved circumferential surface; and
a diameter of a top portion of the diffuser is greater than a diameter of a lower portion of the diffuser.

10. The electric blower according to claim 6 , further comprising flow control vanes each of which is located between adjacent ones of the return guide vanes between the inner circumferential surface of the tubular portion and an outer circumferential surface of the motor.

11. The electric blower according to claim 1 , wherein each return guide vane bends in a circumferential direction at least above the annular lower plate portion.

12. The electric blower according to claim 1 , further comprising an annular portion that joins the return guide vanes to one another at inner ends of the return guide vanes.

Assignees

• Nidec Corp

Inventors

• Hayamitsu Ryosuke

Classifications

• F04D25/06

  the pump being electrically driven (F04D25/08 takes precedence) · CPC title

• F04D29/444

  Bladed diffusers · CPC title

• A47L5/22

  with rotary fans · CPC title

• F04D29/30

  Vanes · CPC title

• F04D29/667

  by influencing the flow pattern, e.g. suppression of turbulence · CPC title