Fan with EMI absorbent blades

Patent metadata

Field	Value
Publication number	US-10779449-B1
Application number	US-201916381615-A
Country	US
Kind code	B1
Filing date	Apr 11, 2019
Priority date	Apr 11, 2019
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

An air-moving device with electromagnetic interference (EMI) reduction is provided. The air moving device, which may be embodied as a fan, includes a motor, one or more blades coupled to the motor, and each of the one or more blades comprising EMI absorbent material.

First claim

What is claimed is:

1. A fan, for electromagnetic interference (EMI) reduction, comprising:
a motor;
an impeller attached to the motor; and
the impeller comprising a hub and at least one blade arranged as a screw thread, the impeller configured as an auger and comprising an EMI absorbent material, wherein the at least one blade wraps around the hub for at least half a rotation.

2. The fan of claim 1 , wherein the impeller is coated with the EMI absorbent material.

3. The fan of claim 1 , further comprising:
the EMI absorbent material comprising ferrite material having magnetic domains of an order of microscale or nanoscale.

4. The fan of claim 1 , further comprising:
the EMI absorbent material comprising ferrite material having unaligned dipoles.

5. The fan of claim 1 , further comprising:
the EMI absorbent material comprising powdered iron with at least one of a filler, bonding agent, glue or resin.

6. The fan of claim 1 , further comprising:
the impeller comprising electrically conductive metal with an EMI absorbent coating.

7. The fan of claim 1 , further comprising:
the impeller is electrically insulated or electrically connected relative to an enclosure of the fan.

8. The fan of claim 1 , wherein the EMI absorbent material comprises a magnetic field attenuation material.

9. The fan of claim 1 , wherein the fan is configured to be housed in an enclosure of a computing device.

10. The fan of claim 1 , wherein the at least one blade is gapless.

11. A fan-cooled enclosure with electromagnetic interference (EMI) reduction, comprising:
an electrically grounded enclosure, having an aperture to support airflow, wherein the aperture is of sufficient size to admit EMI;
a motorized fan coupled to the aperture to support the airflow; and
the motorized fan having an impeller comprising a hub and at least one blade arranged as a screw thread, the impeller configured as an auger and comprising an EMI absorbent material, wherein the at least one blade wraps around the hub for at least half a rotation.

12. The fan-cooled enclosure of claim 11 , further comprising:
electrical connection of the one or more blades to the enclosure.

13. The fan-cooled enclosure of claim 11 , further comprising:
the one or more blades electrically isolated from or floating relative to the enclosure.

14. The fan-cooled enclosure of claim 11 , wherein the one or more blades comprising EMI absorbent material are each coated with ferrite material.

15. The fan-cooled enclosure of claim 11 , wherein the EMI absorbent material comprises powdered ferrite.

16. An air-moving device with electromagnetic interference (EMI) reduction, comprising:
a motor;
one or more blades arranged as screw threads coupled to a hub, wherein the one or more blades and the hub are configured as an auger and the hub is coupled to the motor, and wherein the one or more blades wrap around the hub for at least half a rotation; and
each of the one or more blades and the hub consisting of EMI absorbent material.

17. The air-moving device of claim 16 , further comprising:
the one or more blades arranged to rotate, driven by the motor.

18. The air-moving device of claim 16 , further comprising:
the one or more blades arranged to reciprocate, driven by the motor.

19. The air-moving device of claim 16 , wherein the EMI absorbent material comprises ferrite in powdered form in at least one of a filler, bonding agent, glue or resin.

Assignees

• Arista Networks Inc

Inventors

• Cananzi David A

Classifications

• H05K9/0041 Primary

  Ventilation panels having provisions for screening · CPC title

• H05K7/20172

  Fan mounting or fan specifications · CPC title

• F05D2300/507

  Magnetic properties · CPC title

• F04D29/181

  Axial flow rotors (F04D29/185 take precedence) · CPC title

• F04D19/002

  Axial flow fans · CPC title