# US 2021/0175772 A1 · Techniques for sub-micron radial alignment of electric motor components and air flow management to extend motor lifespan

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- Number: US 2021/0175772 A1
- Document ID: US20210175772A1
- Status: Published application
- Kind: A1
- Application number: 17/112,482
- Filed: 2020-12-04
- Published: 2021-06-10
- Earliest claimed: 2019-12-05
- Assignees: SharkNinja Operating LLC
- Applicants: Sharkninja Operating LLC
- Inventors: Reza AINI
- Web page: https://patentgrep.com/patent/US20210175772A1

## CPC

- H02K 9/06: with fans or impellers driven by the machine shaft
- H02K 15/16: Centring rotors within the stators
- H02K 5/161: {radially supporting the rotary shaft at both ends of the rotor (H02K5/165, H02K5/167, H02K5/173 take precedence)}
- H02K 5/207: {with openings in the casing specially adapted for ambient air}
- H02K 7/083: {radially supporting the rotary shaft at both ends of the rotor (H02K7/086, H02K7/09 take precedence)}
- H02K 2213/03: Machines characterised by numerical values, ranges, mathematical expressions or similar information
- H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53})

## Abstract

The present disclosure is generally directed to techniques for radial alignment of motor components relative to each other to achieve a motor with a rotor bore having sub-micron end-to-end deviation. In an embodiment, a rotor bore alignment tool is disclosed herein that can be inserted between motor components, and more particularly, apertures/through holes defined by each of the motor components such as housing sections and a stator assembly. The rotor bore alignment tool includes expandable members that can be selectively transitioned to an extended position to cause each of the motor components to be radially aligned prior to securely coupling the same in a so-called “stack” to form a motor. Once the motor components are coupled together, the resulting motor includes a rotor shaft extending from end-to-end that preferably includes a sub-micron deviation of less than 10 microns, and more preferably less than or equal to 5 microns, for example.

## Claims

### Claim 1

An electric motor, the electric motor comprising:
a first housing portion defining a first rotor receptacle to receive and couple to a first end of a rotor assembly;
a second housing portion defining a second rotor receptacle to receive and couple to a second end of the rotor assembly, the first and second housing portions configured to couple together and collectively provide a rotor bore to receive the rotor assembly; and
a rotor assembly disposed within the rotor bore, the rotor assembly comprising a shaft and at least a first bearing coupled concentrically along the shaft, the first bearing being disposed within the first rotor receptacle of the first housing portion or within the second rotor receptacle of the second housing portion, and wherein the shaft and first bearing are radially aligned with each other based on the rotor bore collectively provided by the first and second housing portions having an end-to-end offset deviation of less than 10 microns.

### Claim 2 (depends on 1)

The electric motor of claim 1, wherein each of the first and second housing portions couple to each other based on first and second interlocking portions, respectively, and wherein the first and second interlocking portions have an offset alignment tolerance of at least 50 microns such that the first and second housing portions slidably couple together and allow for at least 50 microns of radial displacement relative to each other.

### Claim 3 (depends on 2)

The electric motor of claim 2, wherein the rotor bore includes the end-to-end offset deviation of less than 10 microns based on the first and second housing portions being coupled together and radially displaced by virtue of the offset alignment tolerance of the first and second interlocking portions.

### Claim 4 (depends on 1)

The electric motor of claim 1, wherein the first and second housing portions couple to each other using an adhesive.

### Claim 5 (depends on 1)

The electric motor of claim 1, wherein the first and second housing portions couple to each other based on a locking device.

### Claim 6 (depends on 5)

The electric motor of claim 5, wherein the locking device comprises a self-tapping screw.

### Claim 7 (depends on 5)

The electric motor of claim 5, wherein the locking device comprises a metal bolt.

### Claim 8 (depends on 1)

The electric motor of claim 1, further comprising a stator assembly disposed between the first and second housing portions and defining at least a portion of the rotor bore.

### Claim 9 (depends on 1)

The electric motor of claim 1, further comprising a third housing portion configured to couple to the second housing portion, the third housing portion defining an aperture to communicate air into the electric motor.

### Claim 10 (depends on 9)

The electric motor of claim 9, wherein the third housing portion includes at least one pressure regulator valve in fluid communication with an impeller windage chamber defined at least in part by the third housing portion.

### Claim 11 (depends on 10)

The electric motor of claim 10, further comprising a first seal device disposed adjacent the aperture to form an airtight seal with surfaces of an impeller disposed in the impeller windage chamber.

### Claim 12 (depends on 11)

The electric motor of claim 11, wherein the first seal device includes at least one annular projection, and wherein third housing portion defines at least one groove to receive the at least one annular projection to form the airtight seal.

### Claim 13 (depends on 11)

The electric motor of claim 11, wherein the first seal device is formed of material comprising foam, Polytetrafluoroethylene, rubber, and/or nylon.

### Claim 14

A rotor bore alignment device for radial alignment of a bore collectively provided by a plurality of housing portions of an electric motor, the rotor bore alignment device comprising:
a shaft, the shaft having at least one extendable member disposed at a predefined location along the shaft, the at least one extendable member to selectively transition from a retracted orientation to an extended orientation, the retracted orientation causing the at least one extendable member to radially extend from the shaft to a first distance D1, and the extended orientation causing the at least one extendable member to radially extend from the shaft to a second distance D2, the second distance D2 being greater than the first distance D1; and
wherein the shaft is configured to slidably couple into the bore to a predefined position, the predefined position to align the at least one extendable member with at least a first motor component of the electric motor such that transitioning of the at least one extendable member to the extended orientation causes radial alignment of the first motor component with a second motor component of the electric motor.

### Claim 15 (depends on 14)

The rotor bore alignment device of claim 14, wherein the at least one extendable member is a plurality of extendable members, and the bore is collectively defined by at least first and second housing portions of the plurality of housing portions and a stator assembly disposed therebetween, and wherein the predefined position is configured to cause first, second and third extendable members of the plurality of extendable members to align with and engage the first housing portion, the stator assembly, and the second housing portion, respectively, such that transitioning of the plurality of extendable members to the extended orientation causes radial alignment of the bore collectively provided by the first housing portion, the stator assembly, and the second housing portion.

### Claim 16 (depends on 15)

The rotor bore alignment device of claim 15, wherein the bore has an end-to-end offset deviation of less than 10 microns.

### Claim 17 (depends on 14)

The rotor bore alignment device of claim 14, further comprising a flange disposed at an end of the shaft, the flange extending substantially transverse relative to a longitudinal axis of the shaft, and wherein the flange is configured to engage a sidewall of the first or second housing portions and prevent further insertion of the shaft into the bore, the flange configured to engage the sidewall when the shaft gets slidably inserted to the predefined position within the bore.

### Claim 18 (depends on 14)

The rotor bore alignment device of claim 14, wherein the at least one extendable member comprises an annular ring, the annular ring configured to increase in diameter and extend radially outwards from the shaft in response to the at least one extendable member transitioning to the extended orientation.

### Claim 19 (depends on 14)

The rotor bore alignment device of claim 14, wherein the rotor bore alignment device is configured to introduce a clamping force, the clamping force extending substantially parallel to the bore and causing the plurality of housing portions to be displaced towards each other and prevent angular and axial shift of the plurality of housing portions relative to each other.

### Claim 20 (depends on 14)

The rotor bore alignment device of claim 14, further comprising a sleeve disposed on the shaft to slidably engage and disengage the at least one extendable member, the sleeve defining at least one V-groove to selectively displace the at least one extendable member based on linear movement of the sleeve.

### Claim 21 (depends on 20)

The rotor bore alignment device of claim 20, further comprising a threaded bolt within a cavity of the shaft, the threaded bolt to rotate and cause the sleeve to be displaced.

### Claim 22 (depends on 20)

The rotor bore alignment device of claim 20, wherein the sleeve is configured to displace the at least one extendable member away from the shaft and transition the same to the extended orientation.

### Claim 23 (depends on 20)

The rotor bore alignment device of claim 20, wherein the sleeve is configured to be drawn away from the at least one extendable member to allow the at least one extendable member to transition to the retracted orientation.

### Claim 24 (depends on 14)

The rotor bore alignment device of claim 14, wherein the at least one extendable member comprises a material with an elasticity that allows for the at least one extendable member to increase in diameter to extend to the second distance D2 when transitioned to the extended orientation and retract to return to the first distance D1 when transitioned back to the retracted orientation.

### Claim 25 (depends on 14)

The rotor bore alignment device of claim 14, wherein the at least one extendable member comprises Nitrile Butadiene Rubber (NBR), Carboxylated Nitrile Butadiene Rubber (XNBR), and/or Fluroelastomers.

### Claim 26

A diffuser for use with an electric motor, the diffuser comprising:
a cylindrical body defining an opening to allow a shaft of a rotor assembly to extend therethrough; and
a plurality of curved air displacement fins extending radially from the cylindrical body.

### Claim 27 (depends on 26)

The diffuser of claim 26, further comprising a rim coupled to the cylindrical body by way of the plurality of curved air displacement fins.

### Claim 28 (depends on 27)

The diffuser of claim 27, wherein the plurality of curved air displacement fins each include a distal end opposite of the cylindrical body that couples the rim to the cylindrical body.

### Claim 29 (depends on 26)

The diffuser of claim 26, wherein the plurality of curved air displacement fins each include a distal end opposite of the cylindrical body that is exposed to air.

### Claim 30 (depends on 26)

The diffuser of claim 26, wherein the plurality of curved air displacement fins each include a distal end opposite of the cylindrical body that is fully exposed to air.