Electrostatic motor

Patent metadata

Field	Value
Publication number	US-11863086-B2
Application number	US-202117186986-A
Country	US
Kind code	B2
Filing date	Feb 26, 2021
Priority date	Feb 15, 2018
Publication date	Jan 2, 2024
Grant date	Jan 2, 2024

Abstract

An electrostatic motor includes a cylindrical rotor and a stator. Electrodes are disposed on an inside cylindrical surface of the stator. Electrets and/or electrically conductive electrodes are disposed on the cylindrical rotor and a dielectric fluid fills space between the rotor and the stator to prevent discharge of the electrets. A mask is used to charge portions of an electret cylinder or other curved surface.

First claim

What is claimed is:

1. An electrostatic motor, comprising:
a rotor, rotatable about a rotation axis and defining a first cylindrical surface having a longitudinal axis coincident with the rotation axis and having a first plurality of elongated charge members disposed circumferentially on the first cylindrical surface, each first charge member extending parallel to the longitudinal axis;
a stator defining a second cylindrical surface counterfacing, and spaced apart from, the first cylindrical surface and having a second plurality of elongated charge members disposed circumferentially on the second cylindrical surface, each second charge member extending parallel to the longitudinal axis; wherein:
one surface of the first and second cylindrical surfaces is an outside cylindrical surface, and the other surface of the first and second cylindrical surfaces is an inside cylindrical surface, the first and second cylindrical surfaces define a cylindrical shell therebetween, and a dielectric fills the cylindrical shell;
one plurality of charge members of the first and second pluralities of charge members comprises a plurality of electrets arranged such that adjacent electrets are of opposite charge;
the other plurality of charge members of the first and second pluralities of charge members comprises a first plurality of electrodes; the electrostatic motor further comprising:
a plurality of first charging electrodes, one first charging electrode of the plurality of first charging electrodes for each respective electret of the plurality of electrets, each first charging electrode being disposed below, and in intimate contact with, the respective electret.

2. An electrostatic motor according to claim 1 , further comprising:
a first electrically conductive circuit disposed within the rotor or the stator and electrically connecting every other first charging electrode of the plurality of first charging electrodes; and
a second electrically conductive circuit, electrically isolated from the first electrically conductive circuit, disposed within the rotor or the stator and electrically connecting intermediate first charging electrodes of the plurality of first charging electrodes.

3. An electrostatic motor according to claim 1 , further comprising a plurality of second charging electrodes, one second charging electrode of the plurality of second charging electrodes for each respective electret of the plurality of electrets, each second charging electrode being disposed on an opposite side of the respective electret from the corresponding first charging electrode, and in intimate contact with the electret.

4. An electrostatic motor according to claim 3 , further comprising:
a third electrically conductive circuit disposed within the rotor or the stator and electrically connecting every other second charging electrode of the plurality of second charging electrodes; and
a fourth electrically conductive circuit, electrically isolated from the third electrically conductive circuit, disposed within the rotor or the stator and electrically connecting intermediate second charging electrodes of the plurality of second charging electrodes.

5. A method of manufacturing a rotor of an electrostatic motor, the method comprising:
depositing a layer of electrically conductive material on a surface of a cylinder of electret material;
patterning the electrically conductive material to form a plurality of discrete electrodes; and
depositing a layer of electret material on top of the plurality of discrete electrodes to bury a portion, not all, of the electrically conductive material.

Assignees

• Charles Stark Draper Laboratory Inc

Inventors

• Kratchman Louis Beryl
• Bickford James A

Classifications

• H02N1/004 Primary

  in which a body is moved along a path due to interaction with an electric field travelling along the path · CPC title

• H01G7/02

  Electrets, i.e. having a permanently-polarised dielectric · CPC title

• H02N2/10

  producing rotary motion, e.g. rotary motors · CPC title