1. A device for harnessing wind power using linear motion, the device comprising:
reciprocating aerofoil blades that translate linearly converting wind energy into pressurized hydraulic working fluid that can be used for generating electrical energy or producing mechanical power;
a reciprocating piston and hydraulic cylinder arrangement; and
a hydraulic high pressure accumulator that stores hydraulic energy from the hydraulic working liquid being pushed into the high pressure accumulator,
wherein the aerofoil blades drive the piston to build up hydraulic pressure in the accumulator through the piston and hydraulic cylinder arrangement.
2. The device of claim 1 wherein the aerofoil blades translate linearly along rigid guided rails or supporting columns.
3. The device of claim 1 further comprising a digital controller that senses motion of the aerofoil blades, pressures in the hydraulic system, wind parameters, the speed of the aerofoil blade, and power output from the hydraulic system, and controls orientation of the aerofoil blades with respect to wind.
4. The device of claim 1 wherein the aerofoil blades are pivotably connected to a linkage that directly drives the reciprocating piston inside the hydraulic cylinder.
5. The device of claim 1 further comprising a hydraulic control mechanism to ensure that the pressurized hydraulic working fluid is directed to a correct side of the hydraulic cylinder with respect to the piston, the hydraulic control mechanism includes two-way valves with one set of outlets connected to a low pressure side and another set of outlets connected to the high pressure side to ensure pressurized hydraulic working fluid is pushed in the accumulator.
6. The device of claim 5 further comprising a pressure transformer in the high pressure line adjacent to the accumulator.
7. The device of claim 4 having a plurality of parallel reciprocating aerofoil blades that move in synchronization, wherein the linkage is a common connecting rod.
8. The device of claim 7 wherein the plurality of parallel reciprocating aerofoil blades are built on a reciprocating platform and a mast attached to the platform wherein the aerofoil blades can rotate around the mast.
9. The device of claim 8 wherein the aerofoil blades are supported by a second shaft that passes through a trailing edge of the aerofoil blades to ensure synchronous motion of the aerofoil blades, the second shaft is not rigidly fixed to the platform but is free to move in a circular arc around the mast.
10. The device of claim 8 wherein the platform is attached on a rotating disk that is capable of rotating about a vertical axis, wherein the disk can be rotated so that the aerofoil blades are oriented into the wind at an appropriate angle for yaw control.
11. A device for harnessing wind power using linear motion, the device comprising:
a plurality of parallel reciprocating aerofoil blades that translate linearly in synchronization, converting wind energy into pressurized hydraulic working fluid that can be used for generating electrical energy or producing mechanical power;
a reciprocating piston and hydraulic cylinder arrangement; wherein the aerofoil blades are pivotably connected to a linkage that drives the reciprocating piston inside the hydraulic cylinder;
a hydraulic high pressure accumulator that stores hydraulic energy from the pressurized hydraulic working liquid being pushed into the high pressure accumulator; and
a hydraulic control mechanism to ensure that the pressurized hydraulic working fluid is directed to a correct side of the hydraulic cylinder with respect to the piston; and a hydraulic low pressure accumulator that provides the working fluid to be pressurized.
12. The device of claim 11 wherein the plurality of parallel reciprocating aerofoil blades are built on a reciprocating platform and a mast attached to the platform wherein the aerofoil blades can rotate around the mast.
13. The device of claim 12 wherein the aerofoil blades are supported by a second shaft that passes through a trailing edge of the aerofoil blades to ensure synchronous motion of the aerofoil blades, the second shaft is not rigidly fixed to the platform but is free to move in a circular arc around the mast.
14. The device of claim 12 wherein the platform is attached on a rotating disk that is capable of rotating about a vertical axis, wherein the disk can be rotated so that the aerofoil blades are oriented into the wind at an appropriate angle for yaw control.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
We claim:
1. A precision optical element comprising first and second aspheric surfaces, at least one of which is single point machined.
2. A precision optical element according to claim 1, and wherein both surfaces are single point machined.
3. A precision optical element according to claim 1, and wherein said single point machined surface is produced by means of a diamond tool.
4. A precision optical element according to claim 1, and wherein said element is a lens.
5. A precision optical element according to claim 1, and wherein said element is a double-sided mirror.
6. A precision optical element according to claim 1, and wherein said element comprises an infra-red transparent material.
7. A precision optical element according to claim 1, and wherein said element comprises a material selected from the group comprising germanium, zinc selenide, zinc sulphide, gallium arsenide, silicon and calcium fluoride.
8. A precision optical element according to claim 1, and wherein said element further comprises a diffractive optics pattern turned on at least one of its surfaces.
9. A precision optical element according to claim 1, and wherein the precision of at least one of said first and second surfaces is such that the maximum peak to valley irregularity is less than one wavelength of red Helium Neon laser light.
10. A precision optical element comprising first and second aspheric surfaces, at least one of which is single point machined, and which further comprises a diffractive optics pattern machined on at least one of its surfaces.
11. A precision optical element according to claim 10, and wherein both surfaces are single point machined.
12. A method of producing first and second aspheric surfaces on a precision optical element having a radial size, at least said second aspheric surface being produced by means of single point machining, and comprising the steps of:
forming said first aspheric surface on said element;
forming on a vacuum chuck, a support surface of width in its radial direction significantly smaller than said radial size of said element, and having an aspheric form matching said first aspheric surface formed on said element; and
subsequently machining said second aspheric surface on said element while it is held by said first aspheric surface in said vacuum chuck.
13. A method of producing first and second aspheric surfaces on a precision optical element according to claim 12, and wherein said step of forming said first aspheric surface of said element comprises a machining step.
14. A method of producing first and second aspheric surfaces on a precision optical element according to claim 12, and wherein said step of forming on a vacuum chuck a support surface comprises a machining step.
15. A method of producing first and second aspheric surfaces on a precision optical element according to claim 12, and also comprising the step of machining a diffractive optics pattern on at least one of said surfaces.
16. A method of producing first and second aspheric surfaces on a precision optical element according to claim 12, and wherein the precision of said optical element is such that the maximum peak to valley irregularity of at least one of its first and second surfaces is less than one wavelength of red Helium Neon laser light.
17. An optical system comprising at least one precision optical element comprising two aspheric surfaces, at least one of which is single point machined.
18. An optical system comprising at least one precision optical element according to claim 2.
19. An optical system comprising at least one precision optical element produced by means of the method according to claim 12.
20. An optical system according to claim 17, and wherein said at least one precision optical element also comprises a diffractive optics pattern on at least one surface.
21. An optical system according to claim 17, for use in thermal imaging applications.
22. An optical system according to claim 17, and wherein the precision of said optical element is such that the maximum peak to valley irregularity of at least one of its first and second surfaces is less than one wavelength of red Helium Neon laser light.
23. A vacuum chuck for holding a precision optical element having a radial dimension and a first aspheric surface, for single point machining of a second aspheric surface thereon, and comprising a support surface of width significantly smaller than said radial dimension, said support surface having an aspheric form matching that of said first aspheric surface of said element.
24. A vacuum chuck according to claim 23, and wherein the volume inside of said support surface accommodates a vacuum.
25. A vacuum chuck according to claim 23, and comprising at least one passage within said support surface which accommodates a vacuum.
26. An optical system comprising at least one precision optical element, machined in a vacuum chuck according to claim 23.