Light activated rotor

Patent metadata

Field	Value
Publication number	US-9822786-B1
Application number	US-201615093047-A
Country	US
Kind code	B1
Filing date	Apr 7, 2016
Priority date	Mar 22, 2016
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

Provided is a light activated rotor comprising typically a plurality of vanes affixed to a hub rotatable around the longitudinal axis of an axle. Each vane comprises a planar surface oriented generally perpendicular to the longitudinal axis of the axle with each vane separated into a first surface and a second surface. The first and second surface are adjacent and share a common boundary generally perpendicular to the longitudinal axis of the axle. Additionally, the first and second surfaces have differing emissivities. When the light activated rotor is illuminated with a radiant flux, the differing emissivities of the first and second surfaces produce a temperature gradient across the vane and generally perpendicular to the longitudinal axis, and a thermal creep force across the planar surface of the vane generates a revolution of the vane and the affixed hub around the longitudinal axis of the axle.

First claim

What is claimed is:

1. A light activated rotor comprising:
an axle having a longitudinal axis and fixably attached to a foundation;
a hub surrounding the axle and rotatable about the longitudinal axis; and
a vane coupled to the hub where the vane comprises:
a first section, where the first section comprises a first surface, and where the first surface has a first emissivity; and
a second section, where the second section comprises a second surface, and where the second surface has a second emissivity where the second emissivity is less than the first emissivity, and where the second surface and the first surface have a common boundary, where the second surface borders the first surface over a portion of the common boundary, and where the second surface is co-planer with the first surface over the portion of the common boundary, and where a reference plane is parallel with the second surface and the first surface over the portion of the common boundary and an acute angle between the longitudinal axis of the axle and a normal vector of the reference plane is less than 45 degrees.

2. The light activated rotor of claim 1 , where the first section and the second section are in thermal conductive communication through an area A CON , where the portion of the common boundary comprises some portion of the area A CON .

3. The light activated rotor of claim 2 , where a total width W is equal to a first section width added to a second section width, where the first section width is a dimension of the first surface perpendicular to the portion of the common boundary and the second section width is a dimension of the second surface perpendicular to the portion of the common boundary, and where an area of the first surface added to an area of the second surface is equal to an area A EXP , and a length L is equal to the area A EXP divided by the total width W, and where a height H is equal to the area A CON divided by the length L, and where the total width W is greater than 5 times the height H.

4. The light activated rotor of claim 3 , where the total width W is greater than 10 times the height H.

5. The light activated rotor of claim 2 , further comprising an atmosphere surrounding the vane and a radiant flux impinging the first surface and the second surface, and the radiant flux generating a first temperature on the first surface and a second temperature on the second surface, where the first temperature is greater than the second temperature, and the first temperature and the second temperature generating a temperature gradient and generating a thermal creep force in a direction from the first surface to the second surface, and the thermal creep force generating a revolution of the vane around the longitudinal axis of the axle.

6. The light activated rotor of claim 5 , where the atmosphere surrounding the vane comprises air at a pressure of at least 80 kPa, and where a total width W is equal to a first section width added to a second section width, where the first section width is a dimension of the first surface perpendicular to the portion of the common boundary and the second section width is a dimension of the second surface perpendicular to the portion of the common boundary, and where the total width is less than 100 microns.

7. The light activated rotor of claim 6 , where the first emissivity minus the second emissivity is equal to at least 0.1.

8. The light activated rotor of claim 2 , where ε H is the first emissivity and ε C is the second emissivity, and where the first section has a first section width perpendicular to the portion of the common boundary and the second section has a second section width perpendicular to the portion of the common boundary, and where a total width W is equal to the first section width added to the second section width, and where an area of the first surface added to the area of the second surface is equal to an area A EXP and a length L is equal to the area A EXP divided by the total width W, and where a height H is equal to the area A CON divided by the length L, and where k t is a thermal conductivity between the first section and the second section at the area A CON and σ SB is the Stephan-Boltzmann constant, and where a ΔT 1 and a ΔT 2 are defined by the expressions

Δ
⁢

⁢

T
1

=

(

ɛ
H

-

ɛ
C

)

⁢

(

T
ENV
4

-

T
C
4

)

4
⁢

ɛ
H

⁢

T
C
3

and

Δ
⁢

⁢

T
2

=

σ
SB

⁡

(

ɛ
H

-

ɛ
C

)

⁢

W
2

⁡

(

T
ENV
4

-

T
C
4

Assignees

• Us Navy

Inventors

• Larraza Andres
• Wolfe David M

Classifications

• Y02E10/46

  Conversion of thermal power into mechanical power, e.g. Rankine, Stirling or solar thermal engines · CPC title

• F04D29/388

  characterised by construction · CPC title

• F05D2300/50212

  dissimilar · CPC title

• F04D29/023 Primary

  especially adapted for elastic fluid pumps · CPC title

• F05D2300/502

  Thermal properties · CPC title