Field

[0001 ] The present disclosure relates to a motion conversion device and an energy harnessing apparatus having the same.

Background

[0002] Ocean energy takes many forms, including tides, waves and currents. These fonns of ocean energy are generated as a result of flowing of sea water. Since it is a renewable energy source, much research effort has been put into harnessing this energy for electricity generation. Many systems have been developed for this purpose. These known systems generally have complex designs, which are prone to failure due to mechanical faults. They also tend to have relatively low conversion efficiencies due to energy loss in the mechanical process.

Summary of Invention

[0003] It is an object of the present disclosure to substantially overcome or at least alleviate one or more disadvantages of known systems.

[0004] According to one aspect of the present disclosure, there is provided a motion conversion device comprising: an axle adapted to be rotatably mounted on a support; a first bearing mounted on the axle, rotatable to dri ve rotation of the axle in a driving rotation direction, and freely rotatable relative to the axle in a free rotation direction opposite to the driving rotation direction; a first gear mounted on the first bearing and rotatable to drive rotation of the first bearing; a first driving member meshed with the first gear and reciprocatingly moveable to drive rotation of the first gear; and a flywheel mounted on and rotatably driven by the axle.

[0005] According to another aspect, there is provided an energy harnessing apparatus comprising: first and second buoyant members pivotally connected to each other and adapted to float on a body of water; first and second support members mounted on said first and second buoyant members, respectively; a connecting member having a first end pivotally connected to said second support member and a second end defining a frame; a motion conversion device of the present disclosure, said axle being rotatably mounted on said first support member, said first driving member being mounted on and moveable with said frame; and means for harnessing energy from rotation of said flywheel.

[0006] According to another aspect, there is provided an energy harnessing apparatus comprising: a support member; a buoyant member adapted to float on a body of water; tether means for restricting movement of said buoyant member relative to said support member; a connecting member having a first end connected to said tether means and a second end defining a frame; a motion conversion device of the present disclosure, said axle being fixed relative to said support member, said first driving member being mounted on and moveable with said frame; and means for harnessing energy from rotation of said flywheel.

Brief Description of Drawings

[0007] Embodiments of the present disclosure will now be described with referen ce to the drawings, in which:

[0008] Figure 1 shows a perspective view of an embodiment of a motion conversion device;

[0009] Figure 2 shows a schematic view of an embodiment of an energy harnessing apparatus comprising the device of Figure 1 ;

[0010] Figure 3A-3D show perspective views of the apparatus of Figure 2 at different time points in a simulation, respectively;

[001 1] Figure 4 shows a schematic view of another embodiment of an energy harnessing apparatus comprising two implementations of the device of Figure 1 ;

[0012] Figure 5 shows a schematic view of one arrangement of a frame of the energy harnessing apparatus of Figure 4;

[0013] Figure 6 shows a schematic view of another arrangement of the frame of the energy harnessing apparatus of Figure 4; [0014] Figure 7 A shows a motion conversion device with an alternative configuration and an energy harnessing apparatus having the same;

[0015] Figure 7B shows a toothed wheel and a chain of the motion conversion device of Figure 7A;

[0016] Figure 7C shows a schematic diagram showing a portion of the device of Figure 7A;

[0017] Figure 8 shows an example application scenario of the apparatus of Figure 2; and

[0018] Figure 9 shows the motion conversion device of Figure 1 mounted relative to a support bearing.

Description of Embodiments

[0019] Detailed description of example embodiments will now be given with reference to the drawings. It should be noted that like elements are denoted by the same reference numerals in the drawings.

[0020] Figure 1 shows a perspective view of an example embodiment of a motion conversion device 100 according to the present disclosure. In this example, a pull and push type system is described.

[0021 ] The device 100 comprises an axle 1 10, first and second bearings 120a, 120b, first and second gears 130a, 130b, first and second driving members 140a, 140b, and a flywheel 150.

[0022] The axle 110 is adapted to be mounted on a support (not shown in Figure 1), which will be described hereinafter with reference to another example embodiment.

[0023] The first and second bearings 120a, 120b are spaced from each other, mounted on the axle 1 10, rotatable to drive rotation of the axle 1 10 in a driving rotation direction "D", and freely rotatable relative to the axle 1 10 in a free rotation direction "F" opposite to the driving rotation direction "D". Such bearings are sometimes referred to as "freewheel bearings", "one-way bearings" or ratchets. [0024] The first and second gears 130a, 130b are mounted on the first and second bearings 120a, 120b and rotatable to drive rotation of the first and second bearings 120a, 120b, respectively.

[0025] The first and second driving members 140a, 140b are meshed with the first and second gears 130a, 130b and are reciprocatingly moveable to drive rotation of the first and second gears 130a, 130b, respectively. In this embodiment, each of the driving members 140a, 140b is a toothed bar or a gear rack. In addition, the first and second driving members 140a, 140b are arranged on opposite sides of the axle 110. More specifically, with respect to an imaginary plane (not shown) coinciding with and extending along a longitudinal axis of the axle 1 10, the first driving member 140a is arranged on a first side of the imaginary plane while the second driving member 140b is arranged on a second side of the imaginary plane opposite to the first side. Such an arrangement allows the first driving member 140a to contribute to rotation of the axle 1 10 when moving in a first stroke direction "I", and the second driving member 140b to contribute to rotation of the axle 1 10 when moving in a second stroke direction "II" opposite to the first stroke direction "I".

[0026] Specifically, when the first and second driving members 140a, 140b move in the first stroke direction "I": the first driving member 140a causes the first gear 130a and the first bearing 120a to rotate in the driving rotation direction "D", thereby causing the axle 1 10 and the flywheel 150 to rotate in the driving rotation direction "D"; and the second driving member 140b causes the second gear 130b to rotate freely relative to the second bearing 120b in the free rotation direction "F".

[0027] Moreover, when the first and second driving members 140a, 140b move in the second stroke direction "II": the second driving member 140b causes the second gear 130b and the second bearing 120b to rotate in the driving rotation direction "D", thereby causing the axle 1 10 and the flywheel 150 to rotate in the driving rotation direction "D"; and the first driving member 140a causes the first gear 130a to rotate freely relative to the first bearing 120a in the free rotation direction "F".

[0028] In this embodiment, the first and second driving members 140a, 140b are configured to reciprocatingly move in unison with respect to each other to drive the first and second gears 130a, 130b, respectively. In other embodiments (not shown), the first and second driving members 140a, 140b may be configured to move in a non-unison manner. For example, the driving members 140a, 140b may be independently driven by respective sources of reciprocating motion to reciprocate in the stroke directions "I", "II".

[0029] However, the driving members 140a, 140b may be otherwise configured. For example, where each of the gears 130a, 130b is in the form of a toothed wheel, each of the driving members 140a, 140b may take the form of a chain meshed with the corresponding toothed wheel 130a, 130b.

[0030] In this embodiment, the flywheel 150 is mounted on and rotatably driven by the axle 110. In other embodiments, the flywheel may be replaced with other mechanical means with inertia suitable for storing rotational energy of the axle 1 10. Alternatively, means for energy generation may be operatively associated with the axle 1 10 for generating electrical energy from rotation of the axle 110. For example, the means may comprise a generator or a gearbox to which the axle 1 10 is directly connected. The mechanical means may be replaced with weights, for example, a weighted wheel or a set of pulleys with weights at the ends.

[0031 ] An alternative embodiment (not shown) similar to the embodiment of Figure 1, but with only one of the bearings 120a, 120b, the corresponding gear 130a, 130b and the corresponding driving member 140a, 140b, is also envisaged. With such an embodiment, only movement of the corresponding driving member 140a, 140b in one of the stroke directions "I", "II" contributes to rotation of the flywheel 150 in the driving rotation direction "D". In terms of operation, this embodiment is similar to that shown in Figure 1 and will hence not be reiterated herein for the sake of brevity.

[0032] In alternative embodiments, each gear 130a, 130b may take the form of a star, a trapezoid, a pulley, etc.

[0033] Figure 2 illustrates an example embodiment of an energy harnessing apparatus 200 using the motion conversion device 100 of Figure 1. The apparatus 200 further includes first and second buoyant members 210a, 210b, first and second support members 220a, 220b, a connecting member 230, and an energy harnessing means 240 for harnessing energy from rotation of the flywheel 150 resulting from ocean energy. [0034] The buoyant members 210a, 210b are pivotally connected to each other by a hinged connecting mechanism 212, and are adapted to float on a body of water. Each buoyant member 210a, 210b may take the form of a pontoon, a boat or any other floating object with sufficient buoyancy.

[0035] The first and second support members 220a, 220b are mounted on the first and second buoyant members 210a, 210b, respectively. Each support member 220a, 220b is in the fonn of a pylon. However, in other embodiments, each support member 220a, 220b may take any other suitable form, such as a column or a mast.

[0036] The connecting member 230 has one end pivotally connected to an upper end 222b of the second support member 220b, and another end defining or forming a frame 232. In this embodiment, the connecting member 230 comprises in part a bull-push bar arranged midway between the two ends.

[0037] The axle 1 10 is rotatably mounted on an upper end 222a of the first support member 220a. The first and second dri ving members 140a, 140b are mounted on and moveable with the frame 232.

[0038] With such a configuration, the buoyant members 210a, 210b pivotally move with respect to each other via a hinge in response to movement of the body of water. The frame 232 is responsive to relative movement of the buoyant members 210a, 210b to alternately and reciprocatingly move the driving members 140a, 140b in the first and second stroke directions "I", "II". By virtue of th e opposite arrangement of the driving members 140a, 140b with respect to the axle 1 10, more particularly with respect to the imaginary plane, the unison reciprocating movement of the first and second driving members 140a, 140b in the stroke directions "I", "II" causes the first and second gears 130a, 130b to rotate opposite to each other in alternating ones of the driv ing and free rotation directions "D", "F". The first and second bearings 120a, 120b are respectively dri ven by the first and second gears 130a, 130b to alternately drive rotation of the axle 1 10 and the flywheel 150 in the driving rotation direction "D".

[0039] The energy harnessing means 240 may take any fonn suitable for harnessing energy from rotation of the flywheel 150. For example, the energy harnessing means 240 may include a generator arranged to generate electricity from rotation of the flywheel 150. Where the means 240 is connected directly to the axle 1 10, the generator generates electricity from rotation of the axle 110. A battery system conversion system may be provided for storage of electricity thus generated.

[0040] Each of Figures 3A-3D illustrates the apparatus 200 at a respective time point during a simulation in which the apparatus 200 is arranged to float on a body of water, similar in arrangement to the embodiment of Figure 2.

[0041] Figure 3A illustrates the apparatus 200 at a first time point where movement of the driving members 140a, 140b by the frame 232 transitions from the second stroke direction "Π" to the first stroke direction "I". At this time point, the gears 130a, 130b are not driven to rotate by the respective driving members 140a, 140b.

[0042] Figure 3B illustrates the apparatus 200 at a second time point after the first time point, where the driving members 140a, 140b move in the first stroke direction "I". At this time point, the first gear 130a is driven by the first driving member 140a to rotate in the driving rotation direction "D" while the second gear 130b is driven by the second driving member 140b to rotate in the free rotation direction "F".

[0043] Figure 3C illustrates the apparatus 200 at a third time point after the second time point, where movement of the driving members 140a, 140b by the frame 232 transitions from the first stroke direction "I" to the second stroke direction "II". At this time point, the gears 130a, 130b are not driven to rotate by the respective driving members 140a, 140b.

[0044] Figure 3D illustrates the apparatus 200 at a fourth time point after the third time point, where the driving members 140a, 140b move in the second stroke direction "II". At this time point, the second gear 130b is driven by the second driving member 140b to rotate in the driving rotation direction "D" while the first gear 130a is driven by the first driving member 140a to rotate in the free rotation direction "F".

[0045] Figure 4 illustrates another example of an energy harnessing apparatus 300 according to the present disclosure. The energy harnessing apparatus 300 comprises a support member 310, which may be formed from a metal structure, a buoyant member 320, which is anchored at one end, tether means 330, first and second connecting members 340, first and second motion conversion devices 100 that are similar in configuration to that of Figure 1 , and means 360 for harnessing energy from rotation of the flywheel 150. The means 360 may include a generator.

[0046] The support member 310 is shown to be in the form of a pylon. However, the support member 310 may be of any other suitable forms, such as columns or masts, in other

embodiments.

[0047] The buoyant member 320 is adapted to float on a body of water.

[0048] The tether means 330 takes the form of a rope having a middle section and first and second end. The middle section is supported by an upper end 312 of the support member 310. The first end is connected to a first end of the buoyant member 320. The second end is connected to a second end of the buoyant member 320. With such a configuration, the rope serves to restrict movement of the buoyant member 320 on the body of water relative to the support member 310. The rope has a length such that the buoyant member 320 floats on the body of water and that the rope has a sufficient tension for causing movement of the driving members 140a, 140b in response to ocean energy (e.g., waves, currents and tides). However, length of the rope may be otherwise configured depending on configuration of the buoyant member 320 and the tether means 330.

[0049] The first connecting member 340 is connected the rope proximate to the first end thereof. The second connecting member 340 is connected to the rope proximate to the second end thereof. Each of the connecting members 340 has a first end connected to the rope and a second end forming a frame 342. The frame 342 thus formed is similar in function to the frame 232 illustrated in Figure 2.

[0050] In this embodiment, the axle 1 10 is fixed relative to the support member 310. The driving members 140a, 140b of each of the motion conversion devices 100 are mounted on and moveable with the frame 342 of a respective one of the connecting members 340.

[0051] In this embodiment, the apparatus 300 further comprises a guide member 350 mounted on the support member 310 and extending along the body of water. More particularly, the guide member 350 is in the form of an elongated beam extending parallel to the body of water in the direction of reciprocation of the frames 342. The guide member 350 serves to guide movement of the frames 342 therealong.

[0052] Referring to Figure 5, in one arrangement, each frame 342 is provided with a plurality of guide wheels 344. In the arrangement of Figure 5, the guide member 350 is formed with at least one guide groove 352 for guiding movement of the guide wheels 344. Referring to Fi gure 6, in another arrangement, each frame 342 is provided with a plurality of eccentric wheels 346. The guide groove 352 may also be formed in the embodiment of Figure 6 to guide movement of the eccentric wheels 346. Other means (e.g., slides) suitable for facilitating movement of the frames 342 with respect to the guide member 350 may also be employed.

[0053] The eccentric wheels 346 shown in Figure 6 serve to alternately engage and disengage each driving member 140a, 140b with and from the respective gear 130a, 130b. In particular, where movement of the first driving member 140a in the first stroke direction "I" corresponds to rotation of the first gear 130a in the driving rotation direction "D", movement of the second driving member 140b in the second stroke direction "II" corresponds to rotation of the second gear 130b in the driving rotation direction "D". With such an arrangement, the eccentric wheels 346 can be configured: to engage the first driving member 140a with the first gear 130a and to disengage the second driving member 140b from the second gear 130b when the frame 342 moves in the first stroke direction "I"; and to engage the second driving member 140b with the second gear 130b and to disengage the first driving member 140a from the first gear 130a when the frame 342 moves in the second stroke direction "II". Such a configuration is useful in preventing or reducing rotation of the gears 130a, 130b and the bearings 120a, 12b in the free rotation direction "F" where such rotation would not contribute to rotation of the flywheel 150 via the axle 1 10 in the driving rotation direction "D".

[0054] The apparatuses 200, 300 may be further provided with means for harnessing other forms of energy. For example, the apparatuses 200, 300 may be provided with at least one solar panel (not shown) to enhance the efficiency of energy generation. Means for harnessing wind energy may also be provided to the apparatuses 200, 300. With such a configuration, the apparatus 300 is operable to generate electricity from ocean energy. In particular, the buoyant member 320 tethered to the support member 3 10 by the tether means 330 is responsive to ocean energy to move about, imparting via the tether means 330 through the connecting members 340 a reciprocating movement to the frames 342 and driving members 140a, 140b mounted thereon. Operation of the driving member 140a, 140b with respect to the gears 130a, 130b, the bearings 120a, 120b, the axle 110 and the flywheel 150 for energy generation is similar to that described in relation to Figures 1 and 2, and will not be described again herein for the sake of brevity.

[0055] Referring to Figures 7A-7C, in an alternative embodiment of the device 100', each gear 130a', 130b' takes the form of a toothed wheel, and each driving member 140a', 140b' takes the form of a chain driven by the corresponding toothed wheel. Configuration in relation to the bearings 120a', 120b', the axle 1 10 and the flywheel 150 is similar to that shown in Figure 1. The device 100' of this embodiment is installed at a top end of a post, which is mounted on a buoyant member in the form of a pontoon.

[0056] The driving members may also take other forms, such as V-belts and toothed bars. Where the driving members need to be tensioned, the driving members may be biased by a biasing component (e.g., a spring). This may be useful in ensuring that rotation is in the same direction.

[0057] Multiple such apparatuses 200, 300 may be used together for increased energy harnessing efficiency. Figure 8 illustrates one such example arrangement. In the example of Figure 8, a plurality of apparatuses 200 similar in configuration to that of Figure 2 are deployed together, where a plurality of buoyant members 210a'-210e' are configured such that each of the buoyant members 210a'-210e' is pivotally (e.g., hingedly) connected to an adjacent one of the buoyant members 210a'-210e'. The buoyant members 210a'-210e' may be otherwise pivotally connected to perform the same function.

[0058] With such a configuration, each of the apparatuses 200 generates energy in response to ripples or waves passing therethrough. Size, shape and weight of each of the buoyant member may be configured to adjust the amount of force imparted on the driving members 140a, 140b to thereby adjust movement thereof, which results in an adjustment of energy generation.

[0059] Anchors may be provided to ensure that the apparatuses 200, 300 remain located substantially in the same place during use. For example, an anchor may be attached centrally to reduce or restrict loss of movement. Alternatively, as can be seen from the example of Figure 4, the anchor is attached to one side of the buoyant member 320, allowing a wider movement range. [0060] In the example of Figure 4, the apparatus 300 is shown to be constructed to form a single unit by means of a single stack with two columns or spars joined at their ends by a shaft.

[0061] In an alternative arrangement, the axle 1 10, the bearings 120a, 120b, the gears 130a, 130b, and the flywheel 150 may be configured to be reciprocatingly moveable in the stroke directions "I", "II" relative to fixed driving members 140a, 140b. Such a relative movement causes rotation of the gears 130a, 130b in a manner similar to that in the aforementioned embodiments. In other words, relative movement of the driving members 140a, 140b can be achieved by moving instead the other components 1 10, 120a, 120b, 130a, 130b, 150.

[0062] The flywheel may be replaced with other component or mechanism with a suitable inertia for storing rotational energy imparted thereon by the axle 1 10.

[0063] The connecting member may be otherwise configured. For example, in an embodiment where neither of the ends thereof defines a frame, the driving members may still be connected directly to the connecting member.

[0064] The motion conversion devices of the present disclosure have relatively simpl e mechanisms for converting reciprocating motion into rotational motion where such rotational motion is useable for generating electrical energy. By virtue of the devices, the apparatuses of the present disclosure have relatively improved efficiency of harnessing energy from, for example, the ocean.

[0065] Figure 9 shows an example arrangement where the motion conversion device 100 of Figure 1 is mounted relative to a support bearing and on a guide member.