Contactless magnetic couplings for microfluidic devices and nautical propulsion

Patent metadata

Field	Value
Publication number	US-2018172007-A1
Application number	US-201715846565-A
Country	US
Kind code	A1
Filing date	Dec 19, 2017
Priority date	Dec 19, 2016
Publication date	Jun 21, 2018
Grant date	—

Abstract

A device for moving a fluid with magnetic gear includes two first balls each having a shape of sphere, respectively fixed to a rotating first shaft through respective centers of the sphere, each of the first balls having a first magnetic dipole in a direction orthogonal to the first shaft; and a second ball having a shape of sphere attaching a blade structure thereon to move the fluid, fixed to a freely rotatable second shaft through a center of the sphere, and having a second magnetic dipole in a direction orthogonal to the second shaft, wherein the centers of the first and second balls altogether form an isosceles triangle with a vertex angle ψ being defined about the center of the second ball, satisfying

ψ
=

2


arcsin


(

1

3

)

≈

70.53


°
.

First claim

What is claimed is:

1 . A device for moving a fluid with magnetic gear, comprising:
a first shaft that is configured to be rotatable; two first balls each having a shape of sphere, respectively fixed to the first shaft through respective centers of the sphere, each of the first balls having a first magnetic dipole in a direction orthogonal to the first shaft with a center of the first magnetic dipole coinciding with the center of the sphere through which the first shaft penetrates; a second shaft that is freely rotatable and that is disposed in parallel with the first shaft; and a second ball having a shape of sphere, fixed to the second shaft through a center of the sphere of the second ball, the second ball having a second magnetic dipole in a direction orthogonal to the second shaft with a center of the magnetic dipole coinciding with the center of the sphere through which the second shaft penetrates, wherein the respective centers of the first balls and the center of the second ball are arranged so as to form an isosceles triangle with a vertex angle ψ being defined about the center of the second ball and satisfying

ψ
=

2


arcsin


(

1

3

)

≈

70.53

°

and so that the first balls and the second ball form a contactless magnetic gear, transmitting a rotational force of the first shaft to the second shaft, and
wherein at least one of the second shaft and the second ball is physically connected to a blade structure that is placed in a passage of the fluid so that when the first shaft is rotated by an external driving force, the resulting rotation of the second shaft moves the fluid by said blade structure.

2 . The device according to claim 1 ,
wherein a magnitude m 1 of a dipole moment of each of the first magnetic dipoles of the first balls and a magnitude m 2 of a dipole moment of the second magnetic dipole of the second ball satisfy:

μ
≥

μ
c

=

3


3

4

≈
1.299

,

where μ=m 2 /m 1 , and
wherein the first balls are fixed to the first shaft such that an inclination angle δ of a direction of the first magnetic dipole of one of the first balls relative to a direction of the first magnetic dipole of another of the first balls, as seen in a direction of the first shaft, satisfies:

δ
=

±
2


arccos


μ

μ
c

.

3 . The device according to claim 1 ,
wherein a magnitude m 1 of a dipole moment of each of the first magnetic dipoles of the first balls and a magnitude m 2 of a dipole moment of the second magnetic dipole of the second ball satisfy:

μ
≥

μ
c

=

3


3

4

≈
1.299

,

where μ=m 2 /m 1 , and
wherein the first balls are fixed to the first shaft such that the first magnetic dipoles of the first balls are in parallel with each other, thereby making an inclination angle δ of a direction of the first magnetic dipole of one of the first balls relative to a direction of the first magnetic dipole of another of the first balls, as seen in a direction of the first shaft, zero.

4 . A microfluidic device, comprising:
a microfluidic device body having a fluid channel for a fluid to pass through; and the device as set forth in claim 1 , wherein at least the second shaft and the second ball are installed within the microfluidic device body, and wherein a plurality of micro-blades is attached to the second ball, and the second shaft and the second ball with the plurality of micro-blades are disposed in the fluid channel so as to act as a micro-pump for pumping the fluid in the fluid channel.

5 . The microfluidic device according to claim 4 , wherein the first shaft and the first balls are disposed external to the microfluidic device body.

6 . A microfluidic device, comprising:
a microfluidic device body having a fluid channel for a fluid to pass through; and the device as set forth in claim 2 , wherein at least the second shaft and the second ball are installed within the microfluidic device body, and wherein a plurality of micro-blades is attached to the second ball, and the second shaft and the second ball with the plurality of micro-blades are disposed in the fluid channel so as to act as a micro-pump for pumping the fluid in the fluid channel.

7 . The microfluidic device according to claim 6 , wherein the first shaft and the first balls are disposed external to the microfluidic device body.

8 . A microfluidic device, comprising:
a microfluidic device body having a fluid channel for a fluid to pass through; and the device as set forth in claim 3 , wherein at least the second shaft and the second ball are installed within the microfluidic device body, and wherein a plurality of micro-blades is attached to the second ball, and the second shaft and the second ball with the plurality of micro-blades are disposed in the fluid channel so as to act as a micro-pump for pumping the fluid in the fluid channel.

9 . The microfluidic device according to claim 8 , wherein the first shaft and the first balls are disposed external to the microfluidic device body.

10 . A propulsion mechanism for a ship, comprising:
the device as set forth in claim 1 ; and a driving device installed inside a hull of a ship for rotatably driving the first shaft of the device of claim 1 , wherein the first balls and the first shaft are disposed inside the hull of the ship, and wherein the second ball and the second shaft are disposed outsi

Assignees

• Okinawa Inst Science & Tech School Corp

Inventors

• Schoenke Johannes Richard
• Fried Eliot Martin

Classifications

• F04D13/027 Primary

  Details of the magnetic circuit · CPC title

• F04D29/043

  Shafts · CPC title

• H02K49/102

  Magnetic gearings, i.e. assembly of gears, linear or rotary, by which motion is magnetically transferred without physical contact (magnetized gearings with physical contact F16H13/12, F16H49/005) · CPC title

• B63H23/22

  with non-mechanical gearing · CPC title

• B63G2008/004

  autonomously operating · CPC title