WO2019106532A1

WO2019106532A1 - Rotary machine

Info

Publication number: WO2019106532A1
Application number: PCT/IB2018/059346
Authority: WO
Inventors: Adriaan Francois Roberts
Original assignee: Adriaan Francois Roberts
Priority date: 2017-11-29
Filing date: 2018-11-27
Publication date: 2019-06-06
Also published as: ZA201708104B

Abstract

A rotary machine (10) is disclosed. The rotary machine (10) includes a rotor (12) and a rotor cover (18). The rotor (12) is rotatable relative to the rotor cover (18). The rotor (12) is rotatable about an axis of rotation (X) and defines a rotating surface (16). The rotor cover (18) extends adjacent to and radially spaced from a portion of the rotating surface (16) of the rotor (12). In use, with the rotary machine (10) disposed in a fluid, rotation of the rotor (12) in the fluid causes a pressure drop adjacent to the rotating surface (16) of the rotor (12), resulting in a pressure difference between fluid on one side of the rotor cover (18) and fluid on an opposite side of the rotor (12). This results in a force substantially perpendicular to the axis of rotation (X). The rotary machine (10) may form part of a radial motion arrangement (60) and/or may be installed in a container or vehicle, such as a vessel, aircraft or train.

Description

ROTARY MACHINE

FIELD OF THE INVENTION

The invention relates to a rotary machine. The invention also relates to a radial motion arrangement, a vehicle and a container.

BACKGROUND OF THE INVENTION

The Flettner rotor concept has been applied in the development of so-called "rotor ships". A rotor ship typically includes a Flettner rotor in the form of a smooth cylinder rotatably mounted to the ship in a mast-like fashion. The rotor is configured to be rotated about its longitudinal axis and is mechanically driven, in use, e.g. by an electrical motor.

When positioned in a wind stream, a low pressure region and a high pressure region are generated on either side of the rotor, tangential to the direction of the wind stream. This pressure difference is generated as a result of a difference in the speed of air flow relative to the surface of the rotor on opposite sides of the rotor. As a result, a force (thrust) is generated in a direction perpendicular to the direction of the wind stream, which may assist in propelling the ship towards the lower-pressure side of the rotor.

While Flettner rotors have proven to be relatively effective in propelling a ship in a wind stream by harnessing energy from the wind stream, their effectiveness is dependent on favourable wind speeds and/or wind direction. As a result, water propeller systems have largely remained as the mainstream choice for the propulsion of ships, as their performance does not depend on weather conditions to the same extent. The present invention aims to address the issues identified above, at least to some extent.

SUMMARY OF THE INVENTION

In accordance with one aspect of the invention, there is provided a rotary machine which includes:

a rotor which is rotatable about an axis of rotation and which defines a rotating surface; and

a rotor cover which extends adjacent to and radially spaced from a portion of the rotating surface of the rotor, the rotor being rotatable relative to the rotor cover, wherein, with the rotary machine operatively disposed in a fluid, rotation of the rotor in the fluid and relative rotation between the rotor and the rotor cover causes a pressure drop adjacent to the rotating surface of the rotor, resulting in a pressure difference between fluid on one side of the rotor cover and fluid on an opposite side of the rotor, thereby resulting in a force substantially perpendicular to the axis of rotation being exerted on the rotary machine.

The fluid may be a gas (e.g. air) or a liquid. The fluid may be a combination of gas and liquid, a combination of gases or a combination of liquids.

The rotor may be substantially cylindrical. The rotor cover may have an elongate shape and may be positioned so as to cover a substantial portion or the entire length of the rotor in an axial direction.

The rotating surface of the rotor may be an exterior surface of the rotor. The rotor cover may be positioned outside of the rotor in such a manner that it substantially covers the portion of the exterior surface of the rotor. The portion of the exterior surface may be approximately half of the exterior surface.

The rotor cover may define a substantially concave covering surface which is complementally shaped to the rotating surface of the rotor. In some embodiments, the rotor may be at least partially hollow. The rotating surface may be an interior surface of the rotor. The rotor cover may be positioned inside of the rotor in such a manner that it substantially covers the portion of the interior surface of the rotor. The portion of the interior surface may be approximately half of the interior surface.

The rotor may be in the form of an at least partially hollow cylinder and the rotor cover may define a substantially convex covering surface inside of the rotor which is complementally shaped to the interior surface of the rotor.

The rotor may be configured to permit fluid communication between an interior of the rotor and an external environment such that, with the rotary machine operatively disposed in the fluid, prior to relative rotation between the rotor and the rotor cover, an interior fluid pressure in the interior is substantially equal to an exterior fluid pressure in the external environment.

The covering surface may be substantially semi-circular in transverse cross-section.

The rotor may be provided by a hollow drum. The rotor cover may be provided by a generally planar shell which is semi-circular in transverse cross-section.

In some embodiments, the rotary machine may include at least two rotor covers.

In some embodiments, the rotary machine may include a first rotor cover positioned outside of the rotor, e.g. in the manner described above, and a second rotor cover positioned inside of the rotor, e.g. in the manner described above. The first rotor cover may be positioned on one side of the rotor and the second rotor cover may be positioned in an opposite side of the rotor.

The rotary machine may include a rotatable drive shaft drivingly connected to the rotor and defining the axis of rotation. The rotor cover may be secured to the drive shaft by a bearing arrangement such that the shaft is rotatable relative to the rotor cover.

The drive shaft may be configured to be drivingly connected to an electrical motor, or to any other suitable rotating device such as a gear arrangement operatively rotated by an electrical motor.

In some embodiments, the rotary machine may include an electrical motor for driving rotation of the drive shaft and thus the rotor. In some embodiments, rotation of the drive shaft may operatively be driven by a radial motion arrangement as described below.

In some embodiments, the rotary machine may be configured to be positioned with the rotor in a generally upright position, in use, such that the axis of rotation defines an operative vertical axis of the rotary machine and the operative pressure difference between fluid on one the side of the rotor cover and fluid on the opposite side of the rotor results in the force being exerted on the rotary machine in a generally horizontal direction.

Alternatively, the rotary machine may be configured to be positioned with the rotor in a generally horizontal position, in use, such that the axis of rotation defines an operative horizontal axis of the rotary machine and the operative pressure difference between fluid on one the side of the rotor cover and fluid on the opposite side of the rotor results in the force being exerted on the rotary machine in a generally vertical direction.

In some embodiments, the rotary machine may be configured to be positioned with the rotor in a slanted orientation, i.e. between the vertical and horizontal.

In accordance with another aspect of the invention, there is provided a radial motion arrangement which includes a rotary machine substantially as described above, wherein the rotary machine is connected to a fixed point by radial attachment means, the fixed point being spaced apart from the rotary machine, such that, in use, the force exerted on the rotary machine causes the rotary machine to be displaced radially about the fixed point.

The radial attachment means may be provided by one or more base on or in which the rotary machine is positioned, the one or more base being rotatable about a central axis of rotation which defines the fixed point. The one or more base may be provided by bases on both ends of the radial motion arrangement.

In accordance with a further aspect of the invention, there is provided a vehicle which includes a rotary machine substantially as described above.

The vehicle may, for example, be a vessel, an aircraft, or a train.

The rotary machine may be positioned in a generally upright position in the vehicle such that the axis of rotation of the rotor defines an operative vertical axis of the rotary machine and the operative pressure difference between fluid on one the side of the rotor cover and fluid on the opposite side of the rotor results in the force being exerted on the rotary machine, and thus on the vehicle, in a generally horizontal direction.

Alternatively, the rotary machine may be positioned in a generally horizontal position in the vehicle, in use, such that the axis of rotation defines an operative horizontal axis of the rotary machine and the operative pressure difference between fluid on one the side of the rotor cover and fluid on the opposite side of the rotor results in the force being exerted on the rotary machine, and thus on the vehicle, in a generally vertical direction.

In some embodiments, the rotary machine may be positioned with in a slanted orientation in the vehicle, i.e. between the vertical and horizontal.

The vehicle may include a plurality of the rotary machines arranged in the same or in different axial orientations. In accordance with a further aspect of the invention, there is provided a container which includes a rotary machine substantially as described above.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be further described, by way of example, with reference to the accompanying drawings.

In the drawings:

FIG. 1 shows a three-dimensional view of a first embodiment of a rotary machine according to the invention;

FIG. 2 shows a side view of the rotary machine of FIG. 1;

FIG. 3 shows a different side view of the rotary machine of FIG. 1;

FIG. 4 shows a top view of the rotary machine of FIG. 1;

FIG. 5 shows a three-dimensional view of a second embodiment of a rotary machine according to the invention;

FIG. 6 shows a side view of the rotary machine of FIG. 5;

FIG. 7 shows a different side view of the rotary machine of FIG. 5;

FIG. 8 shows a top view of the rotary machine of FIG. 5; and

FIG. 9 shows a top view of an exemplary radial motion arrangement according to the invention.

DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS

The following description of the invention is provided as an enabling teaching of the invention. Those skilled in the relevant art will recognise that many changes can be made to the embodiments described, while still attaining the beneficial results of the present invention. It will also be apparent that some of the desired benefits of the present invention can be attained by selecting some of the features of the present invention without utilising other features. Accordingly, those skilled in the art will recognise that modifications and adaptations to the present invention are possible and can even be desirable in certain circumstances, and are a part of the present invention. Thus, the following description is provided as illustrative of the principles of the present invention and not a limitation thereof.

A first embodiment of a rotary machine 10 (hereinafter referred to as "the machine 10") according to the invention is illustrated in FIGs 1 to 4.

The machine 10 includes a solid, cylindrical rotor 12 which is rotatable about an axis of rotation "X" by way of a drive shaft 14 which extends centrally and longitudinally through the rotor 12 and which defines the axis of rotation X. The drive shaft 14 is configured to be drivingly connected to a suitable electrical motor (not shown).

The rotor 12 defines a rotating surface in the form of an exterior surface 16 of the rotor 12.

The machine 10 further includes a thin, elongate rotor cover 18 extending adjacent to and radially spaced from the exterior surface 16 of the rotor 12. The rotor cover 18 is substantially semi-circular in transverse cross-section and is slightly longer than the rotor 12 such that it covers the entire length of the rotor 12 in the axial direction.

The rotor cover 18 defines a concave covering surface 20 that faces the rotor 12 and covers approximately one half of the exterior surface 16 of the rotor 12, as is most clearly illustrated in FIG. 4. The rotor cover 18 is complementally shaped to the exterior surface 16.

The rotor cover 18 is secured to the shaft 14 by way of bearing arrangements on both ends of the shaft 14. Each bearing arrangement includes a bearing (a housing of which is labelled with numeral 22) permitting the shaft 14 to rotate relative to the rotor cover 18 and two arms 24 in the form of flat plates extending in opposite transverse directions from the bearing housing 22, mechanically securing the rotor cover 18 to the bearing housing 22. In this way, the shaft 14 and rotor 12 are rotatable relative to the rotor cover 18, i.e. the shaft 14 and rotor 12 can be rotated about the axis X while the rotor cover 18 does not rotate relative to the axis X.

In use, when the machine 10 is disposed in a fluid (a gas or liquid), the electrical motor referred to above can be used to rotate the shaft 14 and thus the rotor 12 about the axis X, while the rotor cover 18 does not rotate.

Rotation of the rotor 12 relative to the rotor cover 18 causes a pressure drop adjacent to the exterior surface 16 of the rotor, resulting in a pressure difference between fluid on one side of the rotor cover 18 and fluid on an opposite side of the rotor 12. This opposite side is indicated by the arrow "Y" in FIG. 4. Due to the fact that the rotor cover 18 does not rotate, a pressure difference is generated between the fluid surrounding the rotor 12 and fluid adjacent to an outer surface 23 of the rotor cover 18, resulting in a force acting on the outer surface 23. The higher pressure of the fluid surrounding outer surface 23 of the rotor cover 18 and the lower pressure on the "exposed" or "open" side (Y) of the rotor 12 causes the rotor 12 to move linearly in the direction of the exposed side of the rotor 12. A force "F" (see the arrow in FIG. 4) perpendicular to the axis of rotation X is exerted on the rotary machine 10. This force is linear and is exerted in the direction of the "open" side of the rotor cover 18, as indicated by the arrow F.

A second embodiment of a rotary machine 30 (hereinafter referred to as "the machine 30") according to the invention is illustrated in FIGs 5 to 8.

The machine 30 includes a substantially hollow, cylindrical rotor 32 with an open top 50 and a closed bottom. A disc-shaped end plate 36 is provided so as to close the bottom of the rotor 32. The rotor 32 is rotatable about an axis of rotation "Z" by way of a drive shaft 34 which is secured to the end plate 36 at one end of the rotor 32. The drive shaft 34 is drivingly connected to the rotor 32 by way of the end plate 36 of the rotor 32 and is configured to be drivingly connected to a suitable electrical motor (not shown) for operative rotation. The rotor 32 defines a first rotating surface in the form of an interior surface 38 of the rotor 32 and a second rotating surface in the form of an exterior surface 39, as indicated in FIGs 5 to 8.

The machine 30 further includes a thin, elongate rotor cover 40 extending adjacent to and radially spaced from the interior surface 38 of the rotor 32. The rotor cover 40 is substantially semi-circular in transverse cross-section. In this embodiment, the rotor cover 40 is positioned inside of the rotor 32, as shown in FIGs 5 and 8. This embodiment thus differs from the machine 10 described with reference to FIGs 1 to 4, in which the rotor cover 18 is positioned outside of the rotor 32. The rotor cover 40 is slightly shorter than the rotor 32, but covers the majority of the length of the rotor 32 in the axial direction.

The rotor cover 40 defines a convex covering surface 42 (see FIG. 8) that covers approximately one half of the interior surface 38 of the rotor 32, as is most clearly illustrated in FIG. 8. The rotor cover 40 is complementally shaped to the interior surface 38.

The rotor cover 40 is secured to the shaft 34 by way of a connecting arm 46, which connects the rotor cover 40 to the shaft 34 via a bearing (a housing of which is labelled with numeral 48). In this way, the shaft 34 and the rotor 32 are rotatable relative to the rotor cover 40, i.e. they can be rotated about the axis of rotation Z while the rotor cover 40 does not rotate relative to the axis Z.

In use, when the machine 30 is disposed in a fluid (a gas or liquid), the electrical motor referred to above can used to rotate the shaft 34 and thus the rotor 32 about the axis Z, while the rotor cover 40 does not rotate. Relative rotation between the rotor 32 and the rotor cover 40 causes a pressure drop adjacent to the surface 39 (see the arrows "Q" in FIG. 8) with the pressure adjacent to an internal surface 41 of the rotor cover 40 being higher than the pressure adjacent to the surface 39. This results in a force "G" being exerted on the machine 30, in a direction perpendicular to the axis Z, as shown in FIG. 8. The open top 50 of the rotor 32 permits fluid communication between the interior of the rotor 32 and an external environment such that, with the machine 30 operatively disposed in fluid, prior to relative rotation between the rotor 32 and the rotor cover 40, an interior fluid pressure in the interior of the rotor 32 and the interior of the rotor cover 40 is substantially equal to an exterior fluid pressure in the external environment.

It is envisaged that a machine according to embodiments of the invention, e.g. the machine 10 or the machine 30, may be used in any suitable object which is required to be moved or to provide movement. Particularly, the machine 10 or 30 may be installed in a vehicle or container to propel the vehicle or container or to assist with the propulsion thereof. The vehicle may, for example, be a vessel, an aircraft, a train, or any other suitable vehicle.

As an example, the machine 10 or 30 may be positioned in a generally upright position in the vehicle or container (e.g. in the positions as shown in FIGs 1 to 3 and FIGs 5 to 7) such that the axis of rotation X or Z of the rotor 12 or 32 defines an operative vertical axis of the machine 10 or 30 and the operative pressure difference between fluid on one the side of the rotor cover 18 or 40 and fluid on the opposite side of the rotor 12 or 32 results in a force being exerted on the machine 10 or 30 in a generally horizontal direction, thereby driving or assisting with propulsion. This force may propel the vehicle or container towards the "lower pressure" side of the machine 10 or 30 and the vehicle or container can be directed to ensure that the "lower pressure" side faces the intended direction of travel.

The machines 10 and 30 may also be installed in a radial motion arrangement, an example of which is illustrated in FIG. 9 with reference to the machine 10 of FIGs 1 to

4.

In the radial motion arrangement 60 of FIG. 9, a large, disc-shaped base plate 62 is configured to rotate about a central axis of rotation, i.e. a "fixed point" 64. The machine 10 is positioned on the base plate 62 and is radially spaced apart from the fixed point 64. In use, the machine 10 may be driven, e.g. by an electrical motor as described above, to generate a force perpendicular to the axis of rotation X of the machine 10. This force causes the machine 10 to be displaced radially about the fixed point 64, as indicated by the broken lines and arrows 66 in FIG. 9, thus producing torque about the fixed point 64.

It should be appreciated that rotation of the rotary machine described herein may be driven by any suitable device or system, including a radial motion arrangement. Accordingly, aforementioned references to an electric motor may be replaced with references to a radial motion arrangement such as the one described with reference to FIG. 9.

The Inventor believes that embodiments of the present invention may address issues associated with conventional Flettner rotors. The Inventor has found that embodiments of the present invention are not dependent on favourable wind speeds and/or wind direction, as the required pressure drop may be generated through relative rotation between the rotor, or drum, and one or more "stationary" rotor cover, or shell.

The Inventor therefore believes that embodiments of the invention may be effectively applied for generating linear motion, particularly (but not limited to) linear motion for the propulsion of ships. The Inventor has further found that embodiments of the invention may be applied to generate radial ortorsional motion, e.g. as described with reference to FIG. 9.

Claims

1. A rotary machine which includes:

a rotor cover which extends adjacent to and radially spaced from a portion of the rotating surface of the rotor, the rotor being rotatable relative to the rotor cover,

wherein, with the rotary machine operatively disposed in a fluid, rotation of the rotor in the fluid and relative rotation between the rotor and the rotor cover causes a pressure drop adjacent to the rotating surface of the rotor, resulting in a pressure difference between fluid on one side of the rotor cover and fluid on an opposite side of the rotor, thereby resulting in a force substantially perpendicular to the axis of rotation being exerted on the rotary machine.

2. The rotary machine according to claim 1, wherein the rotor cover has an elongate shape and is positioned so as to cover a substantial portion of a length of the rotor in an axial direction.

3. The rotary machine according to claim 1 or claim 2, wherein the rotating surface of the rotor is an exterior surface of the rotor, and wherein the rotor cover is positioned outside of the rotor in such a manner that it substantially covers the portion of the rotating surface of the rotor.

4. The rotary machine according to claim 3, wherein the rotor is substantially cylindrical and the rotor cover defines a substantially concave covering surface which is complementally shaped to the rotating surface of the rotor.

5. The rotary machine according to claim 4, wherein the covering surface is substantially semi-circular in transverse cross-section and wherein the portion of the rotating surface of the rotor is approximately one half of the exterior surface of the rotor.

6. The rotary machine according to claim 1 or claim 2, wherein the rotor is at least partially hollow, wherein the rotating surface of the rotor is an interior surface of the rotor, and wherein the rotor cover is positioned inside of the rotor in such a manner that it substantially covers the portion of the rotating surface of the rotor.

7. The rotary machine according to claim 6, wherein the rotor is in the form of an at least partially hollow cylinder and the rotor cover defines a substantially convex covering surface which is complementally shaped to the rotating surface of the rotor.

8. The rotary machine according to claim 7, wherein the covering surface is substantially semi-circular in transverse cross-section and wherein the portion of the rotating surface of the rotor is approximately one half of the interior surface of the rotor.

9. The rotary machine according to any one of claims 6 to 8, wherein the rotor is configured to permit fluid communication between an interior of the rotor and an external environment such that, with the rotary machine operatively disposed in the fluid, prior to relative rotation between the rotor and the rotor cover, an interior fluid pressure in the interior is substantially equal to an exterior fluid pressure in the external environment.

10. The rotary machine according to any one of claims 3 to 5 in combination with any one of claims 6 to 9, wherein the rotary machine includes at least two rotor covers, wherein at least one of the at least two rotor covers is positioned outside of the rotor and at least one of the at least two rotor covers is positioned inside of the rotor.

11. The rotary machine according to claim 10, which includes a first rotor cover positioned outside of the rotor and a second rotor cover positioned on the inside of the rotor, wherein the first rotor cover is positioned on one side of the rotor and the second rotor cover is positioned in an opposite side of the rotor.

12. The rotary machine according to any one of the preceding claims, which includes a rotatable drive shaft drivingly connected to the rotor and defining the axis of rotation.

13. The rotary machine according to claim 12, wherein the rotor cover is secured to the drive shaft by a bearing arrangement such that the drive shaft is rotatable relative to the rotor cover.

14. The rotary machine according to claim 12 or claim 13, wherein the drive shaft is configured to be drivingly connected to an electrical motor.

15. The rotary machine according to claim 12 or claim 13, which includes an electrical motor which is drivingly connected to the drive shaft.

16. The rotary machine according to claim 12 or claim 13, wherein the drive shaft is configured to be drivingly connected to a radial motion arrangement.

17. The rotary machine according to any one of the preceding claims, which is configured to be positioned with the rotor in a generally upright position, in use, such that the axis of rotation defines an operative vertical axis of the rotary machine and the pressure difference between fluid on one the side of the rotor cover and fluid on the opposite side of the rotor results in the force being exerted on the rotary machine in a generally horizontal direction.

18. The rotary machine according to any one of claims 1 to 16, which is configured to be positioned with the rotor in a generally horizontal position, in use, such that the axis of rotation defines an operative horizontal axis of the rotary machine and the pressure difference between fluid on one the side of the rotor cover and fluid on the opposite side of the rotor results in the force being exerted on the rotary machine in a generally vertical direction.

19. The rotary machine according to any one of claims 1 to 16, which is configured to be positioned with the rotor in a slanted orientation.

20. A radial motion arrangement which includes a rotary machine according to any one of the preceding claims, wherein the rotary machine is connected to a fixed point by radial attachment means, the fixed point being spaced apart from the rotary machine, such that, in use, the force exerted on the rotary machine causes the rotary machine to be displaced radially about the fixed point.

21. The radial motion arrangement according to claim 20, wherein the radial attachment means is provided by one or more base on or in which the rotary machine is positioned, the one or more base being rotatable about a central axis of rotation which defines the fixed point.

22. A vehicle which includes a rotary machine according to any one of claims 1 to 16.

23. The vehicle according to claim 22, wherein the rotary machine is positioned in a generally upright position in the vehicle such that the axis of rotation of the rotor defines an operative vertical axis of the rotary machine and the pressure difference between fluid on one the side of the rotor cover and fluid on the opposite side of the rotor results in the force being exerted on the rotary machine, and thus on the vehicle, in a generally horizontal direction.

24. The vehicle according to claim 22, wherein the rotary machine is positioned in a generally horizontal position in the vehicle such that the axis of rotation of the rotor defines an operative horizontal axis of the rotary machine and the pressure difference between fluid on one the side of the rotor cover and fluid on the opposite side of the rotor results in the force being exerted on the rotary machine, and thus on the vehicle, in a generally vertical direction.

25. The vehicle according to claim 22, wherein the rotary machine is positioned in a slanted orientation in the vehicle.

26. The vehicle according to claim 22, wherein the vehicle is a vessel, an aircraft, or a train.

27. A container which includes a rotary machine according to any one of claims 1 to 19.