Compact fan assembly with thrust bearing

Patent metadata

Field	Value
Publication number	US-9341192-B2
Application number	US-201314061682-A
Country	US
Kind code	B2
Filing date	Oct 23, 2013
Priority date	Mar 4, 2011
Publication date	May 17, 2016
Grant date	May 17, 2016

Abstract

A fan assembly for a computing device is disclosed. The fan assembly can include an impeller having a number of blades and a motor for turning the blades. The motor can turn the blades via a magnetic interaction between the impeller and the motor. A fluid dynamic thrust bearing can be used to control a position of the impeller relative to the motor. In particular, the impeller can be configured to rotate around an axis and the thrust bearing can be used to control movement of the impeller in a direction aligned with the rotational axis. In one embodiment, the thrust bearing can be configured to stabilize the impeller when vibratory forces act upon the fan assembly. More particularly, parameters associated with the thrust bearing can be selected to counteract vibratory forces emitted by a speaker system.

First claim

What is claimed is:

1. A blower assembly suitable for operation in proximity to a vibration source, the blower assembly comprising:
a housing including an inlet for receiving air and an outlet for expelling the air; and
a rotational fan assembly, comprising:
an impeller having a plurality of fan blades,
a shaft having a first end coupled to a central portion of the impeller,
a sleeve surrounding at least a portion of the shaft,
a thrust ring surrounding the shaft and located between the first end of the shaft and a first end of the sleeve, wherein the thrust ring is spaced apart from where the first end of the shaft couples to the central portion of the impeller, and

a dual-thrust bearing comprising a first grooved fluid dynamic bearing at located where the first end of the sleeve abuts the thrust ring, and a second grooved fluid dynamic bearing at a second end of the sleeve opposite the first end and acting in an axial direction opposite an axial direction of the first grooved fluid dynamic bearing, wherein the dual-thrust bearing is configured to limit relative axial motion between the impeller and the housing during operation of the rotational fan assembly.

2. The blower assembly as recited in claim 1 , further comprising a thrust plate disposed at a second end of the shaft, wherein the thrust plate is surround by a fluid.

3. The blower assembly as recited in claim 1 , wherein the blower assembly is a centrifugal flow fan configured to exhaust air directed in a substantially centrifugal direction.

4. The blower assembly of claim 1 , wherein the impeller includes a central hub with a hollow portion and wherein the thrust bearing is disposed within the central hub such that it is at least partially surrounded by the central hub.

5. A fan assembly configured to operate in proximity to a vibration source, the fan assembly comprising:
a housing including an inlet for receiving air and an outlet for expelling the air;
an impeller mounted within the housing and configured to rotate around an axis, the impeller including a shaft extending from a central portion of the impeller;
a sleeve surrounding the shaft;
a thrust ring surrounding the shaft between the sleeve and where the shaft extends from the central portion of the impeller; and
an axial control mechanism comprising a first grooved fluid dynamic bearing at a first end of the sleeve and a second grooved fluid dynamic bearing at a second end of the sleeve acting in an axial direction opposite an axial direction of the first grooved fluid dynamic bearing, wherein the first grooved fluid dynamic bearing includes a first spiral groove and the second grooved fluid dynamic bearing includes a second spiral groove, wherein during an operation of the impeller, the first spiral groove and the second spiral groove combine to increase a pressure of a fluid in the first spiral groove and the second spiral groove to limit relative axial motion between the impeller and the housing.

6. The fan assembly as recited in claim 5 , wherein the vibration source is a speaker system, and wherein the axial control mechanism is configured to axially stabilize the impeller throughout an output range of the speaker system.

7. A computing device fan, comprising:
a housing;
a shaft located within the housing;
an impeller having a plurality of impeller blades secured to the shaft;
a sleeve surrounding at least a portion of the shaft;
a first ring surrounding the shaft proximate a first end of the sleeve, the first ring being separate from the shaft and the sleeve;
a first thrust bearing disposed at the first end of the sleeve and including a first groove; and
a second thrust bearing disposed at a second end of the sleeve opposite the first end and including a second groove, wherein during operation of the impeller the first groove and the second groove combine to increase a pressure of a fluid in the first thrust bearing and the second thrust bearing, the pressure countering an axial force of the impeller relative to the housing.

8. The computing device fan of claim 7 , further comprising a second ring disposed at an end of the shaft and proximate the second end of the sleeve, the second ring being separate from the shaft and the sleeve, wherein the second thrust bearing is disposed at a surface of the second ring.

9. The computing device fan of claim 8 , wherein the second groove is disposed on the surface of the second ring.

10. The computing device fan of claim 7 , further comprising a flange integrally formed at an end of the shaft and proximate the second end of the sleeve, wherein the second thrust bearing is disposed at a surface of the flange.

11. The computing device fan of claim 10 , wherein the second groove is disposed on the surface of the flange.

12. The computing device fan of claim 7 , further including at least one magnet and at least one stator core component that together drive the operation of the impeller and create the axial force thereby, wherein the pressure counters the axial force without requiring any magnetic preloaded force.

13. The computing device fan of claim 7 , wherein the first ring is pressed onto the shaft.

Assignees

• Apple Inc

Inventors

• Aiello Anthony Joseph
• Dybenko Jesse T
• Degner Brett W

Classifications

• H02K7/09

  with magnetic bearings · CPC title

• F04D29/0513

  hydrostatic; hydrodynamic thrust bearings · CPC title

• F16C17/107

  with at least one surface for radial load and at least one surface for axial load · CPC title

• H02K5/1675

  radially supporting the rotary shaft at only one end of the rotor (H02K5/1677 takes precedence) · CPC title

• F04D29/30

  Vanes · CPC title