# US 11,114,930 B2 · Eddy current brake configurations

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- Number: US 11,114,930 B2
- Document ID: US11114930B2
- Status: Granted
- Kind: B2
- Application number: 15/532,975
- Filed: 2015-12-04
- Published: 2018-09-20
- Granted: 2021-09-07
- Earliest claimed: 2014-12-04
- Assignees: Eddy Current Limited Partnership
- Applicants: Eddy Current Limited Partnership
- Inventors: Christopher James Allington; Andrew Karl Diehl; Kevin A. Wright; Weston Hill; Dave Walters
- Web page: https://patentgrep.com/patent/US11114930B2

## CPC

- H02K 49/046: {with an axial airgap}
- A62B 1/08: with brake mechanisms for the winches or pulleys
- B60L 7/28: Eddy-current braking
- F16D 59/02: spring-loaded and adapted to be released by mechanical, fluid, or electromagnetic means
- H02K 7/116: with gears
- H02K 7/12: with auxiliary limited movement of stators, rotors or core parts, e.g. rotors axially movable for the purpose of clutching or braking
- A63B 69/0048: {for mountaineering, e.g. climbing-walls, grip elements for climbing-walls}
- F16D 2121/20: using electromagnets
- Y02T 10/64: Electric machine technologies in electromobility
- H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53})
- A62B: DEVICES, APPARATUS OR METHODS FOR LIFE-SAVING (valves specially adapted for medical use A61M39/00; life-saving devices, apparatus or methods specially adapted for use in water B63C9/00; divers' equipment B63C11/00; specially adopted for use with aircraft, e.g. parachutes, ejector seats, {B64D17/00, B64D25/10}; rescue devices peculiar to mining E21F11/00)
- B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
- F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- A63B: APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT (apparatus for passive exercising, massage A61H)
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

Described herein are eddy current brakes and associated methods of their use, particularly configurations that have a kinematic relationship with at least two rotational degrees of freedom used to tune operation of the brake or apparatus in which the brake is located.

## Claims

### Claim 1

An eddy current brake, comprising:
a magnetic field; and
an electrical conductor;
wherein the magnetic field and electrical conductor can move relative to each other and interact thereby inducing eddy current drag forces; and
wherein the eddy current brake has exactly two rotational degrees of freedom about a first primary axis and a secondary control axis, respectively, and zero linear degrees of freedom, wherein the first primary axis is orthogonal to the secondary control axis, and wherein, during operation, braking action is applied to the first primary axis and the secondary control axis is used to modulate the braking action;
wherein the first primary axis and the secondary control axis intersect.

### Claim 2 (depends on 1)

The eddy current brake as claimed in claim 1, wherein the brake is configured to have a first rotating shaft and an electrical conductor linked to, and rotating with, the shaft.

### Claim 3 (depends on 2)

The eddy current brake as claimed in claim 2, wherein the electrical conductor is located at least partially within the magnetic field when the braking action occurs.

### Claim 4 (depends on 2)

The eddy current brake as claimed in claim 2, wherein relative movement between the electrical conductor and the magnetic field induces eddy current braking forces acting to resist movement of the electrical conductor and in turn acts to resist movement of the shaft.

### Claim 5 (depends on 2)

The eddy current brake as claimed in claim 2, wherein the eddy current brake includes a collar coupled to the shaft, and either one section of the collar, multiple sections of the collar, or the whole collar, is an electrical conductor.

### Claim 6 (depends on 5)

The eddy current brake as claimed in claim 5, wherein the collar is rotatable about the shaft.

### Claim 7 (depends on 6)

The eddy current brake as claimed in claim 6, wherein rotation of the collar rotates the electrical conductor.

### Claim 8 (depends on 7)

The eddy current brake as claimed in claim 7, wherein the shaft, on which the collar and electrical conductor are mounted, is flexible or incorporates a flexible coupling to allow secondary control axis rotation of the collar and electrical conductor thereon.

### Claim 9 (depends on 7)

The eddy current brake as claimed in claim 7, wherein the electrical conductor is rotatable about an axis or axes mounted on the collar and, when shaft rotation occurs, at least part of the electrical conductor rotates outward from the plane of rotation of the collar about another axis or other axes.

### Claim 10 (depends on 1)

The eddy current brake as claimed in claim 1, wherein the magnetic field, within which the electrical conductor moves, is formed by one or more magnets situated on a housing or an external element.

### Claim 11 (depends on 10)

The eddy current brake as claimed in claim 10, wherein the housing or external element defines a cavity inside which the shaft and electrical conductor move.

### Claim 12 (depends on 1)

The eddy current brake as claimed in claim 1, wherein the electrical conductor is linked to a shaft by a line and centrifugal forces acting on the electrical conductor caused by rotation of the shaft urge the electrical conductor to axially rotate away from the shaft.

### Claim 13 (depends on 12)

The eddy current brake as claimed in claim 12, wherein at least one biasing element is used to tune the axial rate of movement of the electrical conductor away from the shaft.

### Claim 14 (depends on 1)

The eddy current brake as claimed in claim 1, wherein the eddy current brake is configured to have a shaft that rotates about a shaft axis of rotation and a collar coupled to the shaft that rotates about the shaft axis of rotation.

### Claim 15 (depends on 14)

The eddy current brake as claimed in claim 14, wherein one or more electrical conductors move rotationally into or out of the magnetic field about a conductor axis of rotation mounted on a circumference of the collar.

### Claim 16

A method of generating an eddy current drag force using an eddy current brake comprising:
a magnetic field;
a shaft; and
a collar coupled to the shaft, wherein at least a portion of the collar is an electrical conductor;
wherein the magnetic field and electrical conductor can move relative to each other and interact thereby inducing eddy current drag forces; and
wherein the eddy current brake has exactly two rotational degrees of freedom and zero degrees of linear freedom, wherein a first primary axis of rotation is orthogonal to a secondary control axis of rotation, and wherein, during operation, braking action is applied to the first primary axis of rotation and the secondary control axis of rotation is used to modulate the braking action;
wherein the first primary axis of rotation and the secondary control axis of rotation intersect;
the method comprising:
applying a driving force to cause varying relative movement between the magnetic field and the at least one electrical conductor; and
by causing movement, making the at least one electrical conductor and magnetic field interact, thereby inducing eddy current drag forces and acting to resist relative motion between the magnetic field and the at least one electrical conductor.

### Claim 17

An eddy current brake, comprising:
a magnetic field; and
an electrical conductor;
wherein the magnetic field and electrical conductor can move relative to each other and interact thereby inducing eddy current drag forces; and
wherein the eddy current brake has exactly two rotational degrees of freedom about a first primary axis and a secondary control axis, respectively, and zero linear degrees of freedom, wherein the first primary axis is orthogonal to the secondary control axis, and wherein, during operation, braking action is applied to the first primary axis and the secondary control axis is used to modulate the braking action;
wherein the eddy current brake is configured to have a first rotating shaft and an electrical conductor linked to, and rotating with, the shaft;
wherein the eddy current brake includes a collar coupled to the shaft, and either one section of the collar, multiple sections of the collar, or the whole collar, is an electrical conductor;
wherein the collar is rotatable about the shaft;
wherein rotation of the collar rotates the electrical conductor;
wherein the shaft, on which the collar and electrical conductor are mounted, is flexible or incorporates a flexible coupling to allow secondary control axis rotation of the collar and electrical conductor thereon.

### Claim 18 (depends on 17)

The eddy current brake as claimed in claim 17, wherein the electrical conductor is located at least partially within the magnetic field when the braking action occurs.

### Claim 19 (depends on 17)

The eddy current brake as claimed in claim 17, wherein relative movement between the electrical conductor and the magnetic field induces eddy current braking forces acting to resist movement of the electrical conductor and in turn acts to resist movement of the shaft.

### Claim 20 (depends on 17)

The eddy current brake as claimed in claim 17, wherein the magnetic field, within which the electrical conductor moves, is formed by one or more magnets situated on a housing or an external element.

### Claim 21 (depends on 20)

The eddy current brake as claimed in claim 20, wherein the housing or external element defines a cavity inside which the shaft and electrical conductor move.

### Claim 22 (depends on 17)

The eddy current brake as claimed in claim 17, wherein at least one biasing element is used to tune the axial rate of movement of the electrical conductor away from the shaft.

### Claim 23 (depends on 17)

The eddy current brake as claimed in claim 17, wherein the shaft and the collar rotate about a shaft axis of rotation.

### Claim 24 (depends on 23)

The eddy current brake as claimed in claim 23, wherein one or more electrical conductors move rotationally into or out of the magnetic field about a conductor axis of rotation mounted on a circumference of the collar.

### Claim 25

An eddy current brake, comprising:
a magnetic field; and
an electrical conductor;
wherein the magnetic field and electrical conductor can move relative to each other and interact thereby inducing eddy current drag forces; and
wherein the eddy current brake has exactly two rotational degrees of freedom about a first primary axis and a secondary control axis, respectively, and zero linear degrees of freedom, wherein the first primary axis is orthogonal to the secondary control axis, and wherein, during operation, braking action is applied to the first primary axis and the secondary control axis is used to modulate the braking action;
wherein the eddy current brake is configured to have a first rotating shaft and an electrical conductor linked to, and rotating with, the shaft;
wherein the eddy current brake includes a collar coupled to the shaft, and either one section of the collar, multiple sections of the collar, or the whole collar, is an electrical conductor;
wherein the collar is rotatable about the shaft;
wherein rotation of the collar rotates the electrical conductor;
wherein the electrical conductor is rotatable about an axis or axes mounted on the collar and, when shaft rotation occurs, at least part of the electrical conductor rotates outward from the plane of rotation of the collar about another axis or other axes.

### Claim 26 (depends on 25)

The eddy current brake as claimed in claim 25, wherein the electrical conductor is located at least partially within the magnetic field when the braking action occurs.

### Claim 27 (depends on 25)

The eddy current brake as claimed in claim 25, wherein relative movement between the electrical conductor and the magnetic field induces eddy current braking forces acting to resist movement of the electrical conductor and in turn acts to resist movement of the shaft.

### Claim 28 (depends on 25)

The eddy current brake as claimed in claim 25, wherein the magnetic field, within which the electrical conductor moves, is formed by one or more magnets situated on a housing or an external element.

### Claim 29 (depends on 28)

The eddy current brake as claimed in claim 28, wherein the housing or external element defines a cavity inside which the shaft and electrical conductor move.

### Claim 30 (depends on 25)

The eddy current brake as claimed in claim 25, wherein at least one biasing element is used to tune the axial rate of movement of the electrical conductor away from the shaft.

### Claim 31 (depends on 25)

The eddy current brake as claimed in claim 25, wherein the shaft and the collar rotate about a shaft axis of rotation.

### Claim 32 (depends on 31)

The eddy current brake as claimed in claim 31, wherein one or more electrical conductors move rotationally into or out of the magnetic field about a conductor axis of rotation mounted on a circumference of the collar.