CYCLOROTORS

Abstract

A cyclorotor is described that can be used as a propulsor for a marine vessel. The cyclorotor includes a rotary housing comprising a main body and a plurality of blade modules arranged circumferentially around the main body. The cyclorotor also includes a plurality of blade assemblies, each blade assembly being located in a respective blade module and having a blade extending from the rotary housing with a blade axis about which it can be pivoted relative to the rotary housing. Each blade assembly is associated with a blade actuator comprising an electric motor and having a drive shaft, a driving gear mechanically connected to the drive shaft and a driven gear mechanically connected to the respective blade assembly for pivoting the respective blade about its blade axis. Each blade module is preferably adapted to be detached and removed from the main body.

Claims

1. A cyclorotor comprising: a rotary housing comprising a main body and a plurality of blade modules arranged circumferentially around the main body; a plurality of blade assemblies, each blade assembly being located in a respective blade module and having a blade extending from the rotary housing with a blade axis about which it can be pivoted relative to the rotary housing; and a plurality of blade actuators, each blade actuator being associated with a respective one of the blade assemblies; wherein each blade actuator comprises: an electric motor having a drive shaft; a driving gear mechanically connected to the drive shaft; and a driven gear mechanically connected to the driving gear and to the respective blade assembly for pivoting the respective blade about its blade axis.

2. The cyclorotor according to claim 1, wherein each blade assembly comprises exactly one bearing assembly rotatably mounting the respective blade, wherein each bearing assembly includes a stationary ring that is fixed to a blade module housing and a rotating ring that is fixed to a root part of the respective blade.

3. The cyclorotor according to claim 2, wherein the driven gear is formed as an integral part of the rotating ring of the respective bearing assembly and the teeth of the driven gear are formed on a surface of the rotating ring.

4. The cyclorotor according to claim 2, wherein the driven gear is formed as a separate component that is fixed to the rotating ring of the respective bearing assembly.

5. The cyclorotor according to claim 4, wherein the driven gear is formed as a ring and the teeth of the driven gear are formed on a surface of the ring.

6. The cyclorotor according to claim 1, wherein the driving and driven gears of each blade actuator define a transmission gear located in the respective blade module.

7. The cyclorotor according to claim 6, wherein each transmission gear is a bevel gear.

8. The cyclorotor according to claim 7, wherein the driven gear of each blade actuator is a conical gear with an axis of rotation substantially parallel to the respective blade axis, and wherein the driving gear of each blade actuator is a conical gear with an axis of rotation substantially perpendicular to the respective blade axis.

9. The cyclorotor according to claim 1, wherein the driving gear of each blade actuator is disengagable from the drive shaft of the respective electric motor.

10. The cyclorotor according to claim 1, wherein the driving gear of each blade actuator is disengagable from the driven gear.

11. The cyclorotor according to claim 1, wherein the driving gear of each blade actuator is mechanically connected to one or both of the drive shaft of the respective electric motor and the respective driven gear by a respective drivetrain.

12. The cyclorotor according to claim 1, further comprising a plurality of openings, each opening providing access between the interior of the main body and the interior of a respective one of the blade modules, wherein a drivetrain of each blade actuator extends through a respective opening during normal use, and wherein the drivetrain is adapted to be selectively reconfigured so that it does not extend through the opening so that the opening can be sealed for blade module replacement.

13. The cyclorotor according to claim 1, further comprising a plurality of openings, each opening providing access between the interior of the main body and the interior of a respective one of the blade modules.

14. The cyclorotor according to claim 13, wherein each opening is defined by a first opening formed in a structural part of the blade module and an aligned second opening formed in an adjacent structural part of the main body.

15. The cyclorotor according to claim 14, further comprising a first panel removably connected to the structural part of the blade module for sealing the first opening, and a second panel removably connected to the structural part of the main body for sealing the second opening.

16. The cyclorotor according to claim 15, further comprising one or more seals between the first panel and the structural part of the blade module and extending around the first opening, and one or more seals between the second panel and the structural part of the main body and extending around the second opening.

17. The cyclorotor according to claim 1, wherein each blade module is removably connected to the main body by a plurality of mechanical fixings.

18. A method of repairing a cyclorotor according to claim 1, the method comprising: sealing a first opening in a blade module to be replaced and optionally an aligned second opening in the main body; and removing the sealed blade module from the main body.

19. The method according to claim 18, further comprising disengaging the driving gear from one or both of the drive shaft of the respective electric motor and the respective driven gear prior to sealing.

20. The method according to claim 18, further comprising: securing a replacement sealed blade module to the main body; and unsealing a first opening in the replacement blade module and the aligned second opening in the main body if sealed.

21. The method according to claim 18, further comprising reengaging the driving gear with one or both of the drive shaft of the respective electric motor and the respective driven gear after unsealing.

22. A marine vessel comprising one or more cyclorotors according to claim 1 mounted to the hull of the marine vessel as a propulsor.

23. The marine vessel according to claim 22, wherein an access opening is provided in the hull of the marine vessel through which winch cables can be attached to a blade module to be replaced.

24. The marine vessel according to claim 23, wherein the access opening is provided in an annular collar that surrounds the rotary housing and which forms a structural part of the hull of the marine vessel.

25. The marine vessel according to claim 22, further comprising an earthing assembly, wherein the earthing assembly comprises an earthing circuit between each blade assembly and an earthing connection on the hull of the marine vessel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0052] FIG. 1 is a perspective view of a propulsor according to the present invention;

[0053] FIG. 2 is a perspective view of the propulsor shown in FIG. 1 installed in the hull of a marine vessel;

[0054] FIG. 3 is a cross section view of the installed propulsor shown in FIG. 2;

[0055] FIGS. 4 to 7 are schematic views showing a blade module and blade actuator;

[0056] FIGS. 8 and 9 are schematic views showing first and second panels secured using mechanical fixings;

[0057] FIG. 10 is a schematic view showing first and second panels secured using watertight mechanical fixings;

[0058] FIGS. 11 and 12 are schematic views of the propulsor shown in FIG. 1 with a blade module removed;

[0059] FIG. 13 is a schematic view of an earthing assembly for a propulsor according to the present invention; and

[0060] FIG. 14 is a schematic view of the propulsor according to the present invention installed in a marine vessel.

DETAILED DESCRIPTION

[0061] Although the following description describes a cyclorotor that is used as a propulsor for a marine vessel, it will be readily understood that the same principles can be applied to other types of cyclorotor, e.g., for wind or water turbines.

[0062] Referring to FIGS. 1 to 3, a propulsor 1 for a marine vessel includes a rotary housing 2. Six blades 4a, 4b, . . . , 4f extend axially from the lower surface 2a of the rotary housing 2. Each blade 4a, 4b, . . . , 4f has a respective blade axis 6 about which it can be pivoted relative to the rotary housing 2 by a blade actuator 8. The propulsor 1 includes six blade actuators 8. Each blade actuator 8 includes an electric motor 10, a drivetrain 12, and a transmission gear 14 for pivoting the respective blade. Each blade 4a, 4b, . . . , 4f is mounted in a respective blade module 16a, 16b, . . . , 16e, 16f that extends radially outwardly from a main body 18 and is mounted on a single bearing assembly 20 (or slewing bearing).

[0063] In FIG. 3, two of the six blade actuators 8 and two of the six bearing assemblies 20 are shown schematically. FIGS. 4 to 6 show one of the blade modules 16d in more detail, and in particular the construction of the respective blade actuator 8 and the respective blade assembly including the bearing assembly 20. It will be readily understood that the other blade actuators and blade assemblies have the same construction. For the following description, it will be assumed that the blade module 16d is to be replaced, e.g., because it is faulty. But it will be readily understood that the same process can be used to replace any of the blade modules 16a, 16b, . . . , 16f.

[0064] A structural part 22 of each blade module 16a, 16b, . . . , 16f forms part of an outer housing and defines an interior in which the respective blade assembly 20 and part of the respective blade actuator 8 is located. Each bearing assembly 20 includes a stationary ring 24 that is fixed to the blade module housingand in particular to a circular mounting ringby mechanical fixings, e.g., bolts or screws, and a rotating ring 26 that is fixed to a root part of the respective blade 4a, 4b, . . . , 4f by mechanical fixings, e.g., bolts or screws.

[0065] A driven gear 28 is formed as a separate component that is fixed to the rotating ring 26 by mechanical fixings, e.g., bolts or screws, so that they rotate together as a unitary rotating component of the bearing assembly 20. The driven gear 28 is a conical gear with an axis of rotation substantially parallel to the respective blade axis 6.

[0066] A driving gear 30 is mechanically connected to the drive shaft 32 of the respective electric motor 10 by the drivetrain 12. The driving gear 30 of each blade actuator 8 is also a conical gear with an axis of rotation substantially perpendicular to the respective blade axis 6. The driven gear 28 and the driving gear 30 together define a bevel gear as a single-stage transmission gear 14 for pivoting the respective blade when the driving gear is rotated by the drive shaft 32 and the drivetrain 12.

[0067] The drivetrain 12 includes a first shaft 12a that is mechanically connected to the drive shaft 32 and a second shaft 12b that is mechanically connected to the driving gear 30 and supported for rotation by a pair of bearings 34. The second shaft 12b is located entirely within the blade module 16f and is fixed (apart from rotation).

[0068] The first shaft 12a includes a radial flange and the second shaft 12b includes a radial flange. The flanges together define a coupling with aligned openings that allow the flanges to be releasably connected together by mechanical fixings, e.g., bolts or screws. The coupling allows the driving gear 30 of each blade actuator 8 to be disengaged from the drive shaft 32 of the respective electric motor 10 as described in more detail below.

[0069] A structural part 36 of the main body 18 forms part of an outer housing and defines an interior in which the six electric motors 10 are located. In another arrangement, each electric motor can be located in a respective blade module. Each driving gear can be mechanically connected to the drive shaft of the respective electric motor and can be mechanically connected directly with the driven gear (i.e., as a single-stage transmission gear) or indirectly by means of a drive belt or drive chain, for example.

[0070] The rotary housing 2 includes six openings 38, each opening providing access from the interior of the main body 18 to the interior of a respective one of the blade modules 16a, 16b, . . . , 16e, 16f. Each opening 38 is defined by a first opening 40 in the structural part 20 of the respective blade module and an aligned second opening 42 formed in the adjacent structural part 36 defining the main body 18.

[0071] During normal use, each drivetrain 12 extends through a respective opening 38 and mechanically connects the drive shaft 32 of the respective electric motor 10 to the driving gear 30. It will be readily understood that if the electric motors 10 are located in the main body 18 and the driving gears 30 are located in a respective blade module 16a, 16b, . . . , 16f, each drivetrain 12 must cross an interface between the main body and the respective blade module, where each interface is effectively defined by the opening 38. If it is necessary to remove one of the blade modules 16a, 16b, . . . , 16f, the respective opening 38 must often be sealed. In order to seal the respective opening, it is necessary to move or reposition the drivetrain 12 so that it does not extend through the opening or cross the interface along which the blade module will be detached from the main body 18.

[0072] The mechanical fixings used to connect the flanges of the first and second shafts 12a and 12b can be removed so that they are no longer connected. As shown in FIG. 5, the electric motor 10 can then be moved backwards on its mounting so that the first shaft 12a is spaced apart from the second shaft 12b-which is fixedand no longer extends through the respective opening 38. The second shaft 12b is now no longer mechanically connected to the drive shaft 32 of the respective electric motor 10 and the disconnected drivetrain 12 will not prevent the blade module 16d from being detached and removed from the main body 18 once the opening 38 is properly sealed. The first shaft 12a can subsequently be removed from the drive shaft 32 as shown in FIG. 6. It will be readily understood that each drivetrain can also be reconfigurable in other ways so that it no longer extends through the opening or across the interface between the main body and the blade module to be replaced. It will also be readily understood that alternative drivetrains can be used, which might include one or more of drive belts, drive chains and gear trains, for example. Such drive belts or drive chains, for example, can be at least partly removed or disconnected if they extend through the opening or across the interface.

[0073] Once the drivetrain 12 no longer extends through the opening 38 between the interior of the main body and the interior of the blade module 16d to be replaced, the opening can be sealed. In particular, both the first and second openings 40 and 42 can be sealed by respective panels 44a and 44b (see FIG. 7). A first panel 44a is used to temporarily seal the first opening 40 in the structural part 22 of the blade module 16d so that water will not enter the interior of the blade module through the first opening when it is removed. A second panel 44b is used to temporarily seal the second opening 42 in the structural part 38 of the main body 18 so that, when the blade module 16d is removed, water will not enter the interior of the main body and the remaining blade modules through the second opening. The first and second panels 44a and 44b are installed from inside the main body of the rotary housing. As shown schematically in FIGS. 8 to 10, the first opening 40 is slightly smaller than the second opening 42. The first opening 40 can therefore be closed and sealed by securing the first panel 44a to the structural part 22 of the blade module to be replaced that surrounds the first opening and which is accessible through the larger second opening 42. The first panel 44a can be fitted from inside the main body 18 and is received through the second opening 42. Once the first panel 44a has been secured, the second opening 42 can be closed and sealed by securing the second panel 44b to the structural part 36 of the main body 18 that surrounds the second opening 42. The first and second panels 44a and 44b are removably connected to the respective structural part of the blade module or the main body by a plurality of mechanical fixings, e.g., bolts or screws.

[0074] In FIGS. 8 and 9, only the mechanical fixings 46 that are used to secure the first panel 44a to the blade module 16d are shown. The mechanical fixings 46 are received through openings in the first panel 44a and are screwed into aligned openings in the structural part 22 of the blade module 16d to be removed. FIGS. 8 and 9 also show how the blade module 16d is removably connected to the main body 18 by a plurality of mechanical fixings 48, e.g., bolts or screws. The mechanical fixings 48 are received through openings 50 in the second panel 44b. Additional openings (not shown) in the second panel receive the mechanical fixings that secure the second panel to the structural part 36 of the main body 18. The mechanical fixings for securing the second panel 44b to the main body 18 are received through the openings in the second panel and are screwed into aligned openings in the structural part 36 of the main body. The openings 50 in the second panel 44b provide access to the mechanical fixings 48, which are received through openings 52 in the structural part 36 of the main body 18 and are screwed into aligned openings 54 in the structural part 22 of the blade module 16d.

[0075] Once the main body 18 and the blade module 16d to be replaced have been made watertight by securing the first and second panels 44a and 44b, the mechanical fixings 48 that secure the main body and the blade module together can be removed, preferably from inside the main body 18. The openings 52 in the structural part 36 of the main body 18 are then filled with plugs or caps 56 so that the main body remains watertight. Alternatively, as shown in FIG. 10, watertight mechanical fixings 58 can be used. Such watertight mechanical fixings 58 are released from the structural part 22 of the blade module 16d but not removed from the structural part 36 of the main body 18. One or more o-ring seals 60 are provided between the shaft of each mechanical fixing 58 and the respective opening 52 in the structural part 22 of the main body 18 to maintain a watertight seal. In FIGS. 8 to 10, other o-rings are also shown that provide a watertight seal between facing surfaces.

[0076] Once the mechanical fixings 48 or 58 have been untightened and removed or released, the blade module 16d is able to be detached from the rest of the rotary housing and can be moved away from the main body 18 in a controlled manner.

[0077] FIGS. 11 and 12 show the blade module 16d after being detached from the main body 18. Adjacent side plates can also be detached before the blade module 16d is detached as shown.

[0078] After a replacement blade module has been installed and secured to the main body 18 by inserting and tightening the mechanical fixings 48 or 58 from inside the main body, the first and second panels 44a and 44b can be removed by untightening and removing the mechanical fixings. It will be readily understood that the first panel 44a will have been secured to the replacement blade module to seal the opening in the casing or housing of the replacement blade module prior to it being installed in place of the removed blade module. The blade module is therefore maintained in a watertight condition during blade module replacement.

[0079] After the opening 38 between the interior of the main body 18 and the interior of the replacement blade module has been opened, the first shaft 12a can be reconnected to the drive shaft 32 and the electric motor 10 can be moved forwards on its mounting so that the flanges of the first and second shafts 12a and 12b are in abutment. The flanges can then be reconnected together such that the drive shaft 32 is mechanically connected to the driving gear 30 of the replacement blade module by the drivetrain 12. It will be readily understood that each drivetrain can also be reconfigurable in other ways so that it extends through the opening and mechanically connects the drive shaft with the driving gear.

[0080] As shown in FIG. 3, the propulsor 1 includes a slewing bearing 62 for rotatably mounting the rotary housing 2. The slewing bearing 62 includes a rotating ring fixed to the rotary housing 2 and a stationary ring. The stationary ring is adapted to be fixed to the hull of the marine vessel by means of a mounting plate 64.

[0081] The slewing bearing 62 includes a driven gear that is fixed to the rotating ring.

[0082] A plurality of rolling elements (not shown) are positioned between the driven and stationary rings.

[0083] FIGS. 2 and 3 show the propulsor 1 mounted within an annular collar H that forms a structural part of the hull of the marine vessel. The annular collar includes an upper annular surface H1, a first inner cylindrical surface H2, an inner frustoconical surface H3, and a second inner cylindrical surface H4. The inner surface H2 is adjacent the slewing bearing 62 and the inner surfaces H3 and H4 define an inner profile of the collar that conforms generally to the outer profile of the rotary housing 2. The rotary housing 2 and the inner surfaces H3 and H4 of the collar are separated by a gap G that allows the rotary housing to rotate freely. The gap G has an open end at the lower surface 2a of the rotary housing 2 and a closed end adjacent the slewing bearing 62. One or more static or dynamic seals (not shown) can be provided at the closed end to provide a watertight seal and prevent the ingress of water into the interior of the rotary housing 2 past the slewing bearing 62.

[0084] During blade module replacement, the weight of the removed blade module 16d must be supported by a support structure (not shown). In one arrangement, the blade module 16d is attached to winch cables that can be used to lower or lift the blade module after it has been detached from the main body. Winch cables can also be used to lower or lift the replacement blade module. The winch cables can be secured to a suitable part of the blade module and can pass through an opening O in the annular collar H that surrounds the propulsorsee FIG. 2. The propulsor 1 can be rotated so that the blade module 16d to be replaced is arranged underneath the opening O and the winch cables can be passed through the opening and secured to the blade module. It will be readily understood that other ways of supporting a blade module can also be used.

[0085] The mounting plate 64 is fixed to the collar H by means of an intermediate fixing structure (not shown) that is positioned between the lower surface of the mounting plate and the upper annular surface H1 of the collar. In an alternative arrangement, the stationary part of the slewing bearing 62 can be fixed directly to the hull of the marine vessel, e.g., to the inner surface H2 of the collar.

[0086] Two driving gears 66a and 66b (or pinion gears) are located radially inside the driven gear of the slewing bearing 62. The first driving gear 66a is mechanically connected to a drive shaft 68a of a first main electric motor 70a. The second driving gear 66b is mechanically connected to a drive shaft 68b of a second main electric motor 70b.

[0087] The driven gear of the slewing bearing 62 and the first driving gear 66a define a first single-stage transmission gear. The driven gear of the slewing bearing 62 and the second driving gear 66b define a second single-stage transmission gear in parallel with the first single-stage transmission gear.

[0088] The first and second main electric motors 70a and 70b are mounted on the mounting plate 64.

[0089] The drive shafts 68a and 68b of the first and second main electric motors 70a and 70b are aligned substantially parallel to the axis of rotation of the rotary housing 2.

[0090] FIG. 13 shows an earthing assembly 100. The earthing assembly 100 provides an electrical earthing circuit 102 between each blade assembly 104 and the hull 106 of the marine vessel. (In FIG. 13 only one blade assembly 104 is shown to be connected to an earthing connection 108 on the marine vessel by a respective earthing circuit 102, but it will be readily understood that all of the blade assemblies are preferably connected to the earthing connection in a similar manner.) Each earthing circuit 102 can include means such as a brush 110 for interfacing the fixed earthing circuit to the blade root which can pivot about the respective blade axis. The brush 110 may be in sliding contact with an annular track 112 on the blade root. A slip ring or other suitable coupling 114 can be used to connect the part of the earthing circuit that rotates with the rotary housing with the part of the earthing circuit that is stationary relative to the hull of the marine vessel. In FIG. 13 a power unit P is shown for generating the circulating currents that protect the marine vessel as part of an impressed current cathodic protection (ICCP) system. The earthing assembly 100 provides a low impedance electrical path for these circulating currents from each blade assembly 104 to the earthing connection 108.