Electrostatic rotating-machine employing dielectric substrates with surface conductors
An electrostatic rotating electrical machine employs axially extending electrically conductive electrodes on a rotor interacting with a corresponding set of axially extending electrodes on a stator, where the electrodes are supported at an outer surface of a dielectric sleeve which continues beneath the electrodes to provide a robust support and to minimize electrode weight.
1. An electrostatic machine comprising:
a first and second stator assembly providing an insulating support extending circumferentially about an axis;
a rotor assembly providing an insulating support extending circumferentially about the axis and supported to rotate about the axis with respect to the first and second stator assembly,
wherein the insulating supports of the first and second stator assembly and rotor assembly, respectively, support circumferentially displaced conductive stator electrodes and circumferentially displaced conductive rotor electrodes;
wherein the conductive stator electrodes and conductive rotor electrodes present mutually opposed surfaces across a gap between the first and second stator assembly and rotor assembly without mechanical contact between the opposed surfaces or between the opposed surfaces and intervening solid bearing materials, the surfaces extending along coaxial circular paths having a common axis;
a liquid dielectric positioned in the gap between the opposed surfaces of the first and second stator assembly and rotor assembly and having a dielectric constant of at least five; and
wherein the insulating supports together with the conductive stator electrodes and conducting rotor electrodes of the first and second stator assembly and rotor assembly present substantially smooth and continuous surfaces having uniform separation across the gap and following the coaxial circular paths on opposite sides of the gap; and
wherein a thickness of the conductive rotor electrodes and the conductive stator electrodes is less than a thickness of the insulating support beneath the conductive rotor electrode measured perpendicularly to the mutually opposed surfaces of the first and second stator assembly and rotor assembly;
wherein the insulating supports of the rotor assembly and the first and second stator assembly are tubular sleeves of nonconductive support material concentrically supported on radially extending insulating plates, the tubular sleeves having radially opposed inner and outer surfaces positioned circumferentially about the axis and wherein the plurality of circumferentially spaced conductive stator electrodes are supported on at least one of the inner and outer surfaces to face corresponding conductive rotor electrodes of the rotor; and
wherein the rotor electrodes on opposite sides of the tubular sleeves communicate with other electrodes on the rotor and with power conductors by means of conductive vias passing through the insulating supports and passing through the radially extending insulating plates.
2. The electrostatic machine of claim 1 wherein the tubular sleeve of nonconductive support material provides a low relative permittivity material circumferentially adjacent to the plurality of axially extending conductive rotor electrodes, the low permittivity material having a permittivity less than that of the liquid dielectric.
3. The electrostatic machine of claim 2 wherein the low permittivity material has a permittivity of less than five.
4. The electrostatic machine of claim 3 wherein the liquid dielectric material has a dielectric constant of at least live and a viscosity less than 100 cP.