DEVICE FOR CONVERTING WAVE ENERGY INTO ELECTRICAL ENERGY

Abstract

A device for converting wave energy into electrical energy has a sliding mass, a guide for the sliding mass, an electric generator provided with a rotor, a rotor shaft integral with the rotor, a first mechanism that connects the sliding mass to the rotor shaft and can convert the motion of the sliding mass on the guide into a rotational motion of the rotor shaft, and a second mechanism interposed between the first mechanism and the rotor shaft to provide the rotor with an one-way rotation, regardless of the direction of motion of the sliding mass. A floating apparatus may include such a device.

Claims

1. A device for converting wave energy into electrical energy, comprising: a sliding mass; a guide for the sliding mass; an electric generator provided with a rotor; a rotor shaft integral with the rotor; a first mechanism that connects the sliding mass to the rotor shaft and is configured to convert the motion of the sliding mass on the guide into a rotational motion of the rotor shaft; and, a second mechanism interposed between the first mechanism and the rotor shaft to provide the rotor with a one-way rotational motion, regardless of the direction of motion of the sliding mass; the second mechanism comprising: a first toothed wheel having a first free pinion engaged therewith with a first sense of engagement; a second toothed wheel having a second free pinion engaged therewith with a second sense of engagement that is opposite to the first sense of engagement, the second toothed wheel being connected to the first toothed wheel so that the two toothed wheels have opposite rotation senses; a third toothed wheel which is engaged with the first and second free pinions and is connected to the rotor shaft, while the first or second toothed wheel is connected to the first mechanism.

2. A device according to claim 1, comprising a mainspring connected to the rotor shaft.

3. A device according to claim 1, comprising a flywheel connected to the rotor shaft.

4. A device according to claim 23, wherein the flywheel comprising a mainspring.

5. A device according to claim 3, the flywheel being located on the sliding mass.

6. A device according to claim 1, the guide having a circular shape.

7. A device according to claim 6, the rotor being coaxial with the guide.

8. A device according to claim 3, the guide being a straight segment and the flywheel being positioned on the rotor axis.

9. A device according to claim 8, the guide being mounted on a rotating platform.

10. A device according to claim 9, comprising an angular damper for damping the rotation of the platform.

11. A device according to claim 10, the damper being of the fluid-dynamic or of the magnetic type.

12. A device for converting wave energy into electrical energy, comprising: a sliding mass; a guide for the sliding mass; an electric generator provided with a rotor; a rotor shaft integral with the rotor; a first mechanism that connects the sliding mass to the rotor shaft and is configured to convert the motion of the sliding mass on the guide into a rotational motion of the rotor shaft; a second mechanism interposed between the first mechanism and the rotor shaft to provide the rotor with a one-way rotational motion, regardless of the direction of motion of the sliding mass; the first mechanism comprising two pulleys and a closed belt or chain extending between said two pulleys, so that one of these two pulleys is coupled to the rotor shaft and the closed belt or chain is fixed to the sliding mass, the first mechanism also comprising a gear train arranged between the rotor shaft and the pulley coupled thereto, the first mechanism thereby being configured to increase rotor speed.

13. (canceled)

14. A device according to claim 12, the second mechanism comprising two pulleys, each of the two pulleys being integral with one respective pulley of the first mechanism, and a closed belt or chain extending between said pulleys, configured so that one of these two pulleys is coupled to the rotor shaft and the belt or chain is fixed to the sliding mass, the sliding mass being connected to the upper segment of one of the belts or chains and to the lower segment of the other belt or chain, the device further comprising two inverted ratchets, one of which being arranged between a pulley belonging to the first mechanism and the rotor shaft, and the other ratchet being arranged between the corresponding pulley of the second mechanism and the rotor shaft.

15. (canceled)

16. A device according to claim 12, the second mechanism comprising a first toothed wheel having a first free pinion engaged therewith with a first sense of engagement, a second toothed wheel having a second free pinion engaged therewith with a second sense of engagement that is opposite to the first sense of engagement, the second toothed wheel being connected to the first toothed wheel so that the two toothed wheels have opposite rotation senses, a third toothed wheel which is engaged with the first and second free pinions and is connected to the rotor shaft, while the first or second toothed wheel is connected to the first mechanism.

17. A floating apparatus comprising a device according to claim 1.

18. A floating apparatus comprising a device according to claim 6.

19. A floating apparatus comprising a device according to claim 8.

20. A floating apparatus comprising a device according to claim 12.

21. A floating apparatus comprising a device according to claim 14.

22. A floating apparatus comprising a device according to claim 16.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Particular embodiments of the present disclosure will now be described by way of non-limiting examples, with reference to the accompanying drawings, in which:

[0024] FIG. 1 is a schematic elevation view of a mechanism that converts rectilinear motion into rotational motion;

[0025] FIG. 2 is an elevation view of a device having a straight guide;

[0026] FIG. 3 is a perspective view of the device shown in FIG. 2;

[0027] FIG. 4 is a perspective view of a device having a circular guide;

[0028] FIG. 5 is a schematic view of a two-chain mechanism;

[0029] FIG. 6 is a perspective view of a two-chain mechanism;

[0030] FIGS. 7A and 7B are schematic views (in two situations) of a mechanical rectifier; and

[0031] FIGS. 8A and 8B are plan views (in two situations) of a mechanical rectifier.

DETAILED DESCRIPTION

[0032] With reference to FIG. 1, a mass 2 is integral with a closed belt (or chain) 4 which is connected to respective pulleys (or chainrings, in the case of a chain) 5 and 5. The mass 2 can slide on a straight guide 1 through use of connectors 3 which also connect the mass 2 to the belt 4. The pulley 5 is integral with the rotor (not shown) of an electric generator 6. Throughout this disclosure the term belt can also be interpreted as chain (and vice versa), and the term pulley as chainring (for a chain), and vice versa.

[0033] The rectilinear motion of the mass 2 on the guide 1 pulls the belt 4 along, which in turn drives the pulleys 5 and 5 in rotation, thus causing the rotor of the generator 6 to rotate, which consequently produces electricity.

[0034] With reference to FIGS. 2 and 3, a device 10 for converting wave energy into electrical energy may include a straight guide 11, a mass 12 that slides on the guide 11 by a linear ball bearing 13 and is integral with a closed belt 14 that extends parallelly to the guide 11 between two pulleys, one of which (reference 15) is mechanically connected to the rotor (not shown) of an electric generator 16, while the other pulley (reference 15) is arranged in the other end of the belt 14. The device may also have a gear train (or transmission) 17 connecting the pulley 15, the generator rotor, and a flywheel 18 also mechanically connected to the generator rotor. A second flywheel 18 is shown in FIG. 3.

[0035] In sum, the device 10 may include a mechanism similar to that of FIG. 1 for converting the rectilinear motion of the mass 11 into a rotational motion of the rotor of the generator 16, although it presents the difference of the flywheel 18 (and 18, when present).

[0036] The flywheel 18 (or 18) provides kinetic energy, in the form of rotational motion, to the rotor shaft when the latter starts decreasing its speed because of a slowdown of the mass 12.

[0037] FIG. 2 shows springs 19 and 19 arranged at and on the ends of the guide 11, whose function is to dampen the impacts of the sliding mass 12 against said ends and to return a part of the energy dissipated in these impacts as a momentum acting in the opposite direction. The mass 12 itself may also incorporate similar springs.

[0038] The above-described elements are mounted on a frame 20 which fastens and secures the assembly.

[0039] The device 10 can be placed in a floating body (not shown), through a plate 30 (FIG. 2) integral thereto, in which the wave action causes successive and varied inclinations of the guide 11, which causes the sliding of the mass 12 on the guide and, consequently, the rotation of the rotor of the generator 16.

[0040] The frame 20 is mounted on a platform 21 which is rotatable with respect to the plate 30. As seen in FIG. 2, the platform 21 can rotate around a shaft 22, so that the device 10 has freedom of rotation on the plate 30, more precisely in the horizontal plane parallel to the plate 30, in the floating body in which it is installed. This configuration allows the platform 21, and hence the device 10, to be oriented in the direction of the dominant wave, that is, perpendicularly to the incident wave front, in order to maximize the wave energy.

[0041] The rotation of the platform 21 is dampened by an angular damper 23 (FIG. 2) in order to prevent such rotation from accelerating too much and averting the platform from the optimal or almost optimal orientation. The angular damper 23 may be of the fluid-dynamic type or of the magnetic type.

[0042] With a two-chain mechanism like that shown in FIGS. 5 and 6, the rotor of the generator (6 or 16) must follow a single sense of rotation (or, in other words, a one-way rotation), whether the mass (2 or 12) moves in one direction or in the opposite direction. This can also be achieved with the mechanical rectifier of FIGS. 7 and 8. A mechanism of this kind (to provide the rotor with a one-way rotation) causes the rotor speed to always be greater than or equal to the speed the rotor would have (by virtue of the motion of the sliding mass) if there were no such mechanism. More specifically, there is no such speed difference when the sliding mass is being accelerated or kept at a constant speed, but it might occur when the sliding mass is decelerating (whether or not it occurs depends, in this case, on the damping provided by the generator and the moment of inertia of the assemblyrotor, rotor shaft, gear train, flywheel, pulleys, etc.).

[0043] FIG. 5 shows a first chain 4 between two pulleys 5 and 5, and a second chain between two pulleys 5 and 5 The pulleys 5 and 5 are connected to the rotor of the generator 6. The sliding mass 2 is integral with the chains 4 and 4, to which it is connected by a connector 3. The connector 3 has two legs, 3a and 3b; the leg 3a is attached to the lower segment of the chain 4 and the leg 3b is attached to the upper segment of the chain 4. With this configuration, the rotation of the pulleys 5 and 5 is opposite to that of the pulleys 5 and 5. By inverted ratchets (not shown), it is possible for just one of the pulleys 5 and 5 to transmit torque to the rotor of the generator at any given moment, and for said transmission to have the same (single) sense of rotation in both cases.

[0044] The mechanism of FIG. 6 is similar to that of FIG. 5 but is shown in more detail. Said mechanism may include a first chain 14 between two pulleys 15 and 15, a second chain 14 between two pulleys 15 and 15, and the mass 12 that can slide on the guide 11, which is installed in the frame 20. The mass 12 is attached to the upper segment of the chain 14 by a leg 26a, and is also attached to the lower segment of the chain 14 by a leg 26b. The legs 26a and 26b belong to a connector 26 that passes through a slot 25 made in the frame 20 above the mass 12. A transmission 27 may include two inverted ratchets (not shown) that are analogous to those described in the previous paragraph. The flywheel 18 is arranged between the transmission 27 and the rotor of the generator 16.

[0045] FIGS. 7A and 7B schematically show a mechanical rectifier, which is the same in both figures but shown in different situations. A first toothed wheel 51 has a first free pinion 52, and a second toothed wheel 51 has a second free pinion 52. The wheels 51 and 51 are engaged, but the senses of engagement of the first free pinion 52 and the second free pinion 52 with their respective wheels (51 and 51, respectively) are opposite. A third toothed wheel 53 is engaged to the two free pinions, 52 and 52. The torque to be transmitted comes from an input wheel 50, which is engaged to the first toothed wheel 51.

[0046] When the input wheel 50 is rotated counterclockwise (FIG. 7A), the first wheel 51 rotates clockwise and the first pinion 52 also, since this is its sense of engagement, and engages with the third wheel 53, which then rotates counterclockwise and drives the second pinion 52 clockwise, which is the sense opposite of its sense of engagement, whereby the second pinion 52 rotates freely and is not an obstacle for the second wheel 51 to rotate counterclockwise in accordance with its sense of engagement with the first wheel 51.

[0047] When the input wheel 50 rotates clockwise (FIG. 7B), the first wheel 51 rotates counterclockwise and the second wheel 51 rotates clockwise. The second pinion 52 also rotates clockwise and drives the third wheel 53 counterclockwise. Thus, the third wheel always rotates counterclockwise and can be connected to the generator rotor.

[0048] FIGS. 8A and 8B show a similar configuration but with different geometry and as seen from above. A first toothed wheel 151 incorporates a first free pinion 152, and a second toothed wheel 151 incorporates a second free pinion 152. The engaging senses of the first free pinion 152 and the second free pinion 152 with their respective wheels (151 and 151, respectively) are opposite. A gear 155 (i.e., an assembly of at least two engaged gears) ensures that the sense of rotation of the wheel 151 is opposite to that of the wheel 151. The gear 155 may assume any arrangement suitable for the wheels 151 and 151 to rotate in opposite senses. The wheel 53 of FIG. 7 is herein divided into two integral wheels 153 and 153, engaged to the pinions 152 and 152, respectively.

[0049] The belt 14 represents the inlet (analogous to reference 50 in FIGS. 7A and 7B) to the mechanism. When the sense of the various movements is the one indicated by the arrows in FIG. 8A, the wheel 153 is driven by the pinion 152 and the pinion 152 rotates idly driven by the wheel 153. When the direction of the various movements is the one indicated by the arrows in FIG. 8B, the wheel 153 is driven by the pinion 152 and the pinion 152 rotates idly driven by the wheel 153. Accordingly, the assembly of wheels 153 and 153 always rotates in the same sense and can be connected to the generator rotor.

[0050] Referring now to FIG. 4, in another embodiment a device 100 comprises a circular guide 111, a mass 112 sliding on the guide 111 by connectors 113, an electric generator 116 provided with a rotor (not shown), a shaft (not shown) integral with the rotor and a flywheel 118 connected to said rotor shaft. The mass 112 is integral with a closed belt 114 which is connected to two pulleys (not shown). A transmission 117 is arranged between one of the pulleys and the generator rotor; the transmission 117 may include a multiplier mechanism and/or a one way mechanism for the generator rotor. The flywheel 118 is located at the same position as the sliding mass 112, in order to increase the total weight of the sliding mass. The generator 116 is located at the center of the circle 111 and is attached to the assembly by a reinforcement 124.

[0051] Although only a number of examples have been disclosed herein, other alternatives, modifications, uses and/or equivalents thereof are possible. Furthermore, all possible combinations of the described examples are also covered. Thus, the scope of the present disclosure should not be limited by particular examples, but should be determined only by a fair reading of the claims that follow.