Patent Application
20180035493
The present invention relates to a heat generating apparatus that recovers thermal energy from kinetic energy of a rotary shaft (rotational energy), and more particularly to an eddy current heat generating apparatus employing permanent magnets (hereinafter referred to simply as “magnets”) and utilizing eddy currents generated by the effects of magnetic fields of the magnets.
In recent years, generation of carbon dioxide accompanying burning of fossil fuels is acknowledged as a problem. Therefore, utilization of natural energy, such as solar thermal energy, wind energy, hydro-energy and the like, is promoted. Among the natural energy, wind energy and hydro-energy are kinetic energy of a fluid. Conventionally, electric power has been generated from kinetic energy of a fluid.
For example, in a typical wind electric generating facility, a propeller receives wind and thereby rotates. The rotary shaft of the propeller is connected to the input shaft of a power generator, and along with the rotation of the propeller, the input shaft of the power generator rotates. Thereby, electric power is generated in the power generator. In short, in a typical wind electric generating facility, wind energy is converted to kinetic energy of the rotary shaft of a propeller, and the kinetic energy of the rotary shaft is converted to electric energy.
Japanese Patent Application Publication No. 2011-89492 (Patent Literature 1) suggests a wind electric generating facility with improved energy use efficiency. The electric generating facility disclosed in Patent Literature 1 includes a heat generator (retarder 30 in Patent Literature 1) that generates thermal energy in the process of converting wind energy to electric energy.
In the wind electric generating facility disclosed in Patent Literature 1, wind energy is converted to kinetic energy of the rotary shaft of a propeller, and the kinetic energy of the propeller is converted to hydraulic energy of a hydraulic pump. The hydraulic energy rotates a hydraulic motor. The spindle of the hydraulic motor is connected to the rotary shaft of the heat generator, and the rotary shaft of the heat generator is connected to the input shaft of a power generator. Along with rotation of the hydraulic motor, the rotary shaft of the heat generator rotates, and the input shaft of the power generator rotates, whereby electricity is generated in the power generator.
The heat generator utilizes eddy currents generated by the effects of magnetic fields of permanent magnets to reduce the rotational speed of the rotary shaft of the heat generator. Accordingly, the rotational speed of the spindle of the hydraulic motor is reduced, and the rotational speed of the propeller is adjusted via the hydraulic pump.
In the heat generator, the generation of eddy currents leads to generation of braking force to reduce the rotational speed of the rotary shaft of the heat generator, and generation of heat as well. Thus, a part of wind energy is converted to thermal energy. According to Patent Literature 1, the heat (thermal energy) is collected in a heat storage device, and the motor is driven by the collected thermal energy, whereby the power generator is driven. Consequently, electricity is generated in the power generator.
The wind electric generating facility disclosed in Patent Literature 1 includes a hydraulic pump and a hydraulic motor between a propeller that is a rotary shaft and a heat generator. Thus, the structure of the facility is complicated. Also, multistage energy conversion is necessary, and a large energy loss is caused during the energy conversion. Accordingly, the thermal energy obtained in the heat generator is small.
In the heat generator disclosed in Patent Literature 1, a plurality of magnets are circumferentially arrayed to face the whole circumference of the inner peripheral surface of a cylindrical rotor. The magnetic poles (the north pole and the south pole) of each of the magnets are circumferentially arranged, and the magnetic pole arrangements of adjacent ones of the circumferentially arrayed magnets are the same. Therefore, the magnetic fields of the magnets do not spread, and the magnetic flux density reaching the rotor is low. Then, the eddy currents generated in the rotor by the effects of magnetic fields of the magnets are low, and it is not possible to achieve sufficient heat generation.
The present invention has been made in view of the current situation described above. An object of the present invention is to provide an eddy current heat generating apparatus that is capable of efficiently recovering thermal energy from kinetic energy of a rotary shaft (rotational energy).
An eddy current heat generating apparatus according to an embodiment of the present invention includes:
a rotary shaft rotatably supported by a non-rotative member;
a cylindrical heat generator fixed to the rotary shaft;
a plurality of permanent magnets arrayed in a circumferential direction along a circumference of the rotary shaft to face an outer peripheral surface or an inner peripheral surface of the heat generator with a gap such that magnetic pole arrangements of circumferentially adjacent ones of the permanent magnets are opposite to each other;
a cylindrical magnet holder holding the permanent magnets;
a switching mechanism that switches between a state to generate magnetic circuits between the permanent magnets and the heat generator and a state to generate no magnetic circuits between the permanent magnets and the heat generator; and
a heat recovery system collecting heat generated in the heat generator.
In the eddy current heat generating apparatus according to the present invention, thermal energy can be recovered from kinetic energy of a rotary shaft efficiently.
An eddy current heat generating apparatus according to an embodiment of the present invention includes a rotary shaft, a heat generator, a plurality of permanent magnets, a magnet holder, a switching mechanism, and a heat recovery system. The rotary shaft is rotatably supported by a non-rotative member. The heat generator is cylindrical and is fixed to the rotary shaft. The plurality of permanent magnets are arrayed to face the outer peripheral surface or the inner peripheral surface of the heat generator with a gap. These magnets are arrayed in a circumferential direction along the circumference of the rotary shaft such that the magnetic pole arrangements of circumferentially adjacent ones of the magnets are opposite to each other. The magnet holder is cylindrical and holds the magnets. The switching mechanism switches between a state to generate magnetic fields between the magnets and the heat generator and a state to generate no magnetic fields between the magnets and the heat generator. The heat recovery system collects heat generated in the heat generator.
In the eddy current heat generating apparatus according to the embodiment, when magnetic circuits are generated between the magnets and the heat generator by operation of the switching mechanism, since the magnetic pole arrangements of adjacent ones of the magnets arrayed to face the heat generator are opposite to each other, the magnetic fields of the magnets spread out, and the magnetic flux density reaching the heat generator becomes high. Accordingly, the eddy currents generated in the heat generator by the effects of magnetic fields of the magnets are high, thereby resulting in achievement of sufficient heat generation. Thus, thermal energy can be recovered from the kinetic energy of the rotary shaft efficiently. It is possible to adjust the magnetic flux density from the magnets to the heat generator by controlling the degree of action of the switching mechanism. This allows for adjustment of the amount of heat generation of the heat generator, thereby leading to adjustment of the amount of recovered heat.
In the heat generating apparatus described above, for example, the following three ways of arrangement (a) to (c) are employable as the magnetic pole arrangement of each of the magnets.
(a) Each of the magnets is laid such that the magnetic poles thereof are arranged in a radial direction from the axis of the rotary shaft. In this case, the magnet holder is ferromagnetic. This way of arrangement will hereinafter be referred to as “radial magnetic pole arrangement”.
(b) Each of the magnets is laid such that the magnetic poles thereof are arranged in a circumferential direction along the circumference of the rotary shaft. Pole pieces are provided between the circumferentially arrayed magnets. In this case, the magnetic holder is non-magnetic. This way of arrangement will hereinafter be referred to as “circumferential magnetic pole arrangement”.
(c) The magnets include primary magnets, and secondary magnets disposed between the circumferentially arrayed primary magnets. Each of the primary magnets is laid such that the magnetic poles thereof are arranged in the radial direction from the axis of the rotary shaft. Each of the secondary magnets is laid such that the magnetic poles thereof are arranged in the circumferential direction along the circumference of the rotary shaft. In this case, the magnet holder is ferromagnetic. This way of arrangement will hereinafter be referred to as “two-directional magnetic pole arrangement”.
In a case in which the radial magnetic pole arrangement is employed in the heat generating apparatus, the magnetic holder may be configured to be movable along the axis of the rotary shaft to serve as the switching mechanism. The switching mechanism having such a configuration will hereinafter be referred to as “axial motion switching mechanism”. The axial motion switching mechanism can be used not only in the case in which the radial magnetic pole arrangement is employed in the heat generating apparatus but also in a case in which the two-directional magnetic pole arrangement is employed in the heat generating apparatus.
In the case in which the radial magnetic pole arrangement is employed in the heat generating apparatus, the switching mechanism may be configured as follows. In the gap between the heat generator and the magnets, a plurality of ferromagnetic plate-shaped switches are arrayed in the circumferential direction along the circumference of the rotary shaft. The placement angles of these switches are the same as the placement angles of the magnets. Either the magnet holder or the array of switches is rotatable around the rotary shaft. The switching mechanism having such a configuration will hereinafter be referred to as “single-row rotation switching mechanism”.
In the case in which the radial magnetic pole arrangement is employed in the heat generating apparatus, the switching mechanism may be configured as follows. The array of magnets is divided into two rows (a first row and a second row), each of the rows extending in the circumferential direction along the circumference of the rotary shaft, and the magnet holder is divided into two sections for the respective rows. In the gap between the heat generator and the magnets, a plurality of ferromagnetic plate-shaped switches are arrayed in the circumferential direction along the circumference of the rotary shaft. The placement angles of these switches are the same as the placement angles of the magnets. Either of the sections of the magnet holder for the first row or the second row is rotatable around the rotary shaft. The switching mechanism having such a configuration will hereinafter be referred to as “two-row rotation switching mechanism”.
In a case in which the circumferential magnetic pole arrangement is employed in the heat generating apparatus, the two-row rotation switching mechanism can be used. In this case, the above-described plate-shaped switches are not necessary.
In the case in which the circumferential magnetic pole arrangement is employed in the heat generating apparatus, the switching mechanism may be configured as follows. The array of magnets is divided into three rows (a first row, a second row and a third row in this order), each of the rows extending in the circumferential direction along the circumference of the rotary shaft, and the magnet holder is divided into three sections for the respective rows. Either the sections of the magnetic holder for the first and the third rows or the section of the magnetic holder for the second row is rotatable around the rotary shaft. The switching mechanism having such a configuration will hereinafter be referred to as “three-row rotation switching mechanism”.
The two-row rotation switching mechanism and the three-row rotation switching mechanism can be used also in a case in which the two-directional magnetic pole arrangement is employed in the heat generating apparatus. In this case, the plate-shaped switches are disposed in the gap between the heat generator and the primary magnets. The placement angles of the switches are the same as the placement angles of the primary magnets.
In the heat generating apparatus, the heat recovery system may include a closed container, pipes, a heat storage device, and a heat medium. The closed container is fixed to a non-rotative member and surrounds the heat generator. The closed container includes a non-magnetic partition wall located in the gap between the heat generator and the magnets. The pipes are connected to an inlet and an outlet, respectively, which lead to the internal space of the closed container. The heat storage device is connected to the pipes. The heat medium circulates in the closed container, the pipes and the heat storage device.
The above-described heat generating apparatus can be mounted in a power-generating facility utilizing kinetic energy of a fluid (for example, natural energy such as wind power, water power or the like), such as a wind electric generating facility, a hydroelectric generating facility or the like. For example, by replacing the power-generating apparatus of a conventional wind electric generating facility or a conventional hydroelectric generating facility with the above-described heat generating apparatus, it becomes possible to generate thermal energy in the facility. Thus, the structure of a conventional power generating facility can be applied to the components of the facility except the heat generating apparatus. The heat generating apparatus can be mounted in a vehicle. In either case, the heat generating apparatus recovers thermal energy from the kinetic energy of the rotary shaft. The collected thermal energy is used, for example, to generate electric energy.
Eddy current heat generating apparatuses according to some embodiments of the present invention will hereinafter be described.
As shown in
The heat generator 4 is fixed to the rotary shaft 3. The heat generator 4 includes a cylindrical heat generating drum 4A that is coaxial with the rotary shaft 3, and a disk-shaped connection member 4B connecting the front edge (right edge in
The magnets 5 are fixed on the outer peripheral surface of the magnet holding ring GA, and face the inner peripheral surface of the heating drum 4A with a gap. In this regard, as shown in
In the case shown by
The heat generator 4, and especially the inner surface layer of the heat generating drum 4A facing the magnets 5, is made of a conductive material. The conductive material may be a ferromagnetic metal material (for example, carbon steel, cast iron or the like), a feebly magnetic material (for example, ferrite stainless steel or the like), or a non-magnetic material (for example, an aluminum alloy, austenite stainless steel, a copper alloy or the like).
Also, as shown in
The partition wall 15 is made of a non-magnetic material (for example, an aluminum alloy, austenite stainless steel, a copper alloy, heat-resistant resin or ceramics). This is to avoid influencing the magnetic fields of the magnets 5 spreading to the heat generator 4. The surface of the partition wall 15 facing the heat generating drum 4A may be a mirror surface with a high degree of smoothness. This suppresses heat transfer from the heat generating drum 4A to the magnets 5.
The heat generating apparatus 1 according to the first embodiment includes an axial motion switching mechanism as the switching mechanism that switches between a state to generate magnetic circuits between the magnets 5 and the heat generator 4 and a state to generate no magnetic circuits between the magnets 5 and the heat generator 4. Specifically, the magnet holding ring GA holding the magnets 5 is configured to be movable along the axis of the rotary shaft 3. For example, a drive source (not shown in the drawings) such as an air cylinder, an electric actuator or the like is connected to the magnet holding ring GA. By operation of the drive source, the magnet holding ring 6A and the magnets 5 are moved together forward or backward in the axial direction. Thereby, the magnets 5 can be put into a state to lie inside the heat generating drum 4A (see
When the rotary shaft 3 rotates, the heat generating drum 4A rotates together with the rotary shaft 3 (see the outlined arrows in
In this state, when the magnets 5 are taken out of the heat generating drum 4A by operation of the axial motion switching mechanism as shown in
On the other hand, when the magnets 5 are placed in the heat generating drum 4A by operation of the axial motion switching mechanism as shown in
Therefore, the magnetic fluxes from the magnets (magnetic fields of the magnets) are as follows (see the solid arrows in
In a state where there is a relative rotational speed difference between the magnets 5 and the heat generating drum 4A, when the magnetic fields of the magnets 5 act on the heat generating drum 4A, eddy currents are generated along the inner peripheral surface of the heat generating drum 4A. Interactions between the eddy currents and the magnetic flux density from the magnets 5 cause braking force acting on the heat generating drum 4A (heat generator 4), which is rotating together with the rotary shaft 3, in the reverse direction to the rotational direction, according to Fleming's left-hand rule.
The generation of eddy currents causes heat generation of the heat generating drum 4A along with the generation of braking force. As described above, the magnetic flux density reaching the heat generating drum 4A is high, and therefore, the eddy currents generated in the heat generating drum 4A by the effects of magnetic fields of the magnets 5 are high, thereby resulting in achievement of sufficient heat generation.
The heat generating apparatus 1 includes a heat recovery system to collect and utilize the heat generated in the heat generating drum 4A (heat generator 4). In the first embodiment, the heat recovery system includes an inlet 11 and an outlet 12 made in the body 2 that forms a closed container together with the cover 8, the partition wall 15. The inlet 11 and the outlet 12 lead to the internal space of the closed container, that is, the space where the heat generating drum 4A lies (the space hereinafter being referred to as “heat generator lying space”). An inlet pipe and an outlet pipe are connected to the inlet 11 and the outlet 12, respectively, that lead to the heat generator lying space though they are not shown in the drawings. The inlet pipe and the outlet pipe are connected to a heat storage device, which is not shown in the drawings. The heat generator lying space (internal space of the closed container), the inlet pipe, the outlet pipe and the heat storage device form a pathway, and a heat medium flows and circulates in the pathway (see the dotted arrows in
The heat medium is, for example, nitrate-based molten salt (for example, mixed salt of sodium nitrate: 60% and potassium nitrate: 40%). Alternatively, heat medium oil, water (steam), air, supercritical CO2 or the like may be used as the heat medium.
The heat generated in the heat generating drum 4A is transferred to the heat medium flowing in the heat generator lying space. The heat medium in the heat generator lying space is discharged therefrom through the outlet 12, and led to the heat storage device via the outlet pipe. The heat storage device receives heat from the heat medium by heat exchange, and stores the heat therein. The heat medium that has passed through the heat storage device flows into the inlet pipe, and returns to the heat generator lying space through the inlet 11. In this way, the heat generated in the heat generating drum 4A is collected.
In the heat generating apparatus 1 according to the first embodiment, as described above, sufficient heat generation is achieved by the heat generating drum 4A. Therefore, it is possible to recover thermal energy from kinetic energy of the rotary shaft 3 efficiently.
Moreover, when the degree of action of the axial motion switching mechanism is controlled to place part of the magnets 5 inside the heat generating drum 4A, the magnetic flux density of the magnets 5 reaching the heat generating drum 4A is different from that when the magnets 5 are entirely placed inside the heat generating drum 4A. Thus, controlling the degree of action of the axial motion switching mechanism allows for adjustment of the amount of heat generation in the heat generating drum 4A, thereby resulting in adjustment of the amount of collected heat. The control of the degree of action of the switching mechanism is carried out under an order from a control unit (not shown) to maintain a constant amount of collected heat, for example. Specifically, the control unit detects the number of rotations of the rotary shaft 3 by a rotary encoder or any other sensor, and controls the degree of action of the switching mechanism depending on the detected number of rotations. For example, when the number of rotations of the rotary shaft 3 decreases, the control unit controls the switching mechanism so that the magnetic flux density from the magnets 5 to the heat generating drum 4A will be higher. When the number of rotations of the rotary shaft 3 increases, the control unit controls the switching mechanism so that the magnet flux density from the magnets 5 to the heat generating drum 4A will be lower.
Switching to the state to generate no magnetic circuits between the magnets 5 and the heat generating drum 4A is carried out under an order from a control unit (not shown) when the amount of heat stored in the heat storage device has reached the capacity, for example. Specifically, the control unit detects the temperature inside the heat storage device, and judges from the detected temperature whether or not the amount of heat stored therein has reached the capacity. When the amount of stored heat has reached the capacity, the control unit controls the switching mechanism so that no magnetic circuits will be generated between the magnets 5 and the heat generating drum 4A. Thereafter, when the amount of heat stored in the heat storage device falls below the capacity along with consumption of heat stored therein, the control unit controls the switching mechanism so that magnetic circuits will be generated between the magnets 5 and the heat generating drum 4A.
The heat generating apparatus 1 according to the first embodiment is mounted in a wind electric generating facility. As shown in
In the wind electric generating facility, the propeller 20 receives wind and rotates (see the outlined arrow in
The rotation of the rotary shaft 3 of the heat generating apparatus 1 causes generation of heat in the heat generator 4 and generation of braking force in the rotary shaft 3 to decrease the rotational speed. Thereby, the rotational speed of the propeller 20 is adjusted via the accelerator 24 and the clutch 23. The clutch 23 has the following functions. When heat generation in the heat generating apparatus 1 is needed, the clutch 23 connects the rotary shaft of the propeller 20 to the rotary shaft 3 of the heat generating apparatus 1. Thereby, the rotating force of the propeller 20 is transmitted to the heat generating apparatus 1. When heat generation is no longer necessary because heat is stored in the heat storage device to capacity or when the heat generating apparatus 1 needs to be stopped for maintenance, the clutch 23 disconnects the rotary shaft of the propeller 20 from the rotary shaft 3 of the heat generating apparatus 1. Thereby, the rotating force of the propeller 20 is not transmitted to the heat generating apparatus 1. In order to prevent the propeller 20 from rotating freely by wind on the occasion, it is preferred that a brake system of a frictional type, an electromagnetic type or the like to stop the rotation of the propeller 20 is provided between the propeller 20 and the clutch 23.
As described above, the eddy currents generated in the heat generating drum 4A cause heat generation in the heat generating drum 4A. Therefore, the magnets 5 may rise in temperature by heat from the heat generating drum 4A (for example, radiant heat), thereby decreasing the magnetic force of the magnets 5. Therefore, it is preferred to take a measure to inhibit the temperature rise of the magnets 5.
On this point, in the heat generating apparatus 1 according to the first embodiment, the partition wall 15 of the closed container blocks the heat from the heat generating drum 4A. Therefore, it is possible to prevent the magnets 5 from rising in temperature.
Buffer layers 4e are provided between the base 4a and the first layer 4b, between the first layer 4b and the second layer 4c and between the second layer 4c and the oxidation resistant coating 4d. Each of the buffer layers 4e has a linear expansion coefficient that is greater than the linear expansion coefficient of one of its adjacent materials and smaller than the linear expansion coefficient of the other of its adjacent materials. This is for prevention of delamination. The buffer layers 4e are, for example, NiP (nickel-phosphorus) plated layers.
This layered structure increases the eddy currents generated in the heat generating drum 4A by the effects of magnetic fields of the magnets 5, thereby resulting in achievement of great braking force and sufficient heat generation. However, the second layer 4c may be omitted, and further, the buffer layers 4e may be omitted.
As shown in
The outer surfaces of the pole pieces 9 project from the outer surfaces of the magnets 5 toward the inner peripheral surface of the heat generating drum 4A. Meanwhile, the inner surfaces of the pole pieces 9 are located farther on the outer side than the inner surfaces of the magnets 5. A gap is kept between each of the pole pieces 9 and the magnet holding ring 6A. In
As in the first embodiment, the heat generating apparatus according to the second embodiment includes an axial motion switching mechanism as the switching mechanism that switches between a state to generate magnetic circuits between the magnets 5 and the heat generator 4 and a state to generate no magnetic circuits between the magnets 5 and the heat generator 4.
In the second embodiment, when the magnets 5 are taken out of the heat generating drum 4A by operation of the axial motion switching mechanism, no magnetic circuits are generated between the magnets 5 and the heat generating drum 4A as shown in
As shown in
Accordingly, the heat generating apparatus according to the second embodiment has the same effects as the heat generating apparatus according to the first embodiment.
As shown in
As shown in
As in the first embodiment, the heat generating apparatus according to the third embodiment includes an axial motion switching mechanism as the switching mechanism that switches between a state to generate magnetic circuits between the magnets 5A, 5B and the heat generator 4 and a state to generate no magnetic circuits between the magnets 5A, 5B and the heat generator 4.
In the third embodiment, when the magnets 5A and 5B are taken out of the heat generating drum 4A by operation of the axial motion switching mechanism, no magnetic circuits are generated between the magnets 5A, 5B and the heat generating drum 4A as shown in
As shown in
With regard to a first primary magnet 5A and a second primary magnet 5A that are adjacent to each other, the magnetic flux outgoing from the north pole of the first primary magnet 5A through the pole piece 10 fixed thereon reaches the heat generating drum 4A facing the first primary magnet 5A. On the magnetic flux, the magnetic flux outgoing from the north pole of the secondary magnet 5B that is in contact with the first primary magnet 5A is superimposed. The magnetic flux that has reached the heat generating drum 4A reaches the south pole of the second primary magnet 5A through the pole piece 10 fixed thereon. The magnetic flux outgoing from the north pole of the second primary magnet 5A reaches the south pole of the first primary magnet 5A via the magnet holding ring 6A. Thus, the circumferentially adjacent primary magnets 5A form a magnetic circuit across the adjacent primary magnets 5A, the magnet holding ring 6A holding the magnets 5A and 5B, and the heat generating drum 4A. Such magnetic circuits are formed throughout the whole circumference such that adjacent magnetic fluxes are in opposite directions. Then, the magnetic fields of the magnets 5A and 5B spread out, and the magnetic flux density reaching the heat generating ring 4A (heat generator 4) becomes high.
Therefore, the heat generating apparatus according to the third embodiment has the same effects as the heat generating apparatus according to the first embodiment.
The heat generating apparatus according to the fourth embodiment includes a single-row rotation switching mechanism as the switching mechanism that switches between a state to generate magnetic circuits between the magnets and the heat generator and a state to generate no magnetic circuits between the magnets and the heat generator. Specifically, as shown in
Both sides of the respective switches 30 are held by a switch holding ring (not shown). The switch holding ring is in the shape of a cylinder that is coaxial with the rotary shaft 3, and is fixed to the body 2. The magnetic holding ring 6A holding the magnets 5 is rotatable around the rotary shaft 3. For example, a drive source (not shown in the drawings) such as an air cylinder, an electric actuator or the like is connected to the magnetic holding ring 6A. By operation of the drive source, the magnet holding ring CA and the magnets 5 are rotated together. Thereby, the switches 30 can be put into a state where each of the switches 30 entirely overlaps the magnet 5 immediately below (see
In the heat generating apparatus according to the fourth embodiment, the partition wall 15 (see
In the fourth embodiment, when the single-row rotation switching mechanism puts the switches 30 into a state where each of the switches 30 lies across two adjacent magnets 5, the magnetic fluxes from the magnets 5 (magnetic fields of the magnets 5) are as follows (see the solid arrows in
On the other hand, when the single-row rotation switching mechanism puts the switches 30 into a state where each of the switches 30 entirely overlaps the magnet 5 immediately below, the magnetic fluxes from the magnets 5 (magnetic field of the magnet 5) are as follows (see the solid arrows in
Therefore, the heat generating apparatus according to the fourth embodiment has the same effects as the heat generating apparatus according to the first embodiment. Moreover, the single-row rotation switching mechanism employed in the fourth embodiment allows for a reduction in the entire length of the apparatus, and accordingly is effective for downsizing of the apparatus.
When the degree of action of the single-row rotation switching mechanism is controlled to put the switches 30 into a state where each of the switches 30 partly overlaps the magnet 5 below without lying across two adjacent magnets 5, the magnetic flux density of the magnets 5 reaching the heat generating drum 4A is different from that when each of the switches 30 entirely overlaps the magnet 5 below. Thus, controlling the degree of action of the single-row rotation switching mechanism allows for adjustment of the amount of heat generation in the heat generating drum 4A, thereby resulting in adjustment of the amount of collected heat.
The heat generating apparatus according to the fifth embodiment includes a two-row rotation switching mechanism as the switching mechanism that switches between a state to generate magnetic circuits between the magnets and the heat generator and a state to generate no magnetic circuits between the magnets and the heat generator.
Specifically, as shown in
In the gap between the heat generating drum 4A (heat generator 4) and the magnets 5, a plurality of ferromagnetic plate-shaped switches 30 are arrayed in the circumferential direction along the circumference of the rotary shaft 3 throughout the whole circumference. Unlike the array of magnets 5 and the magnetic holding ring 6A, the array of switches 30 is not divided. The placement angles of the switches 30 are the same as the placement angles of the magnets 5. Each of the switches 30 has a size as follows. The dimension of the switch 30 in the circumferential direction along the circumference of the rotary shaft 3 is nearly equal to that of each of the magnets 5 (see
Both sides of the respective switches 30 are held by a switch holding ring (not shown in the drawings). The switch holding ring is in the shape of a cylinder that is coaxial with the rotary shaft 3, and is fixed to the body 2.
Out of the first and the second sections of the magnetic holding ring 6A, the first section of the magnetic holding ring GA for the first row is fixed to the body 2. The second section of the magnetic holding ring 6A for the second row is rotatable around the rotary shaft 3. For example, a drive source such as an air cylinder, an electric actuator or the like is connected to the second section of the magnetic holding ring GA though it is not shown in the drawings. By operation of the drive source, the second section of the magnet holding ring 6A and the second row of magnets 5 are rotated together. Thereby, the magnets 5 can be put into a state where magnets that have the same magnetic pole arrangement are positioned completely in alignment with each other in the axial direction along the axis of the rotary shaft 3 as two adjacent magnets 5 that are located in the first row and in the second row respectively (see
In the heat generating apparatus according to the fifth embodiment, the partition wall 15 (see
In the fifth embodiment, when the two-row rotation switching mechanism puts the magnets 5 into a state where magnets that have opposite magnetic pole arrangements are positioned completely in alignment with each other in the axial direction as two adjacent magnets 5 that are located in the first row and in the second row respectively, the magnetic fluxes from the magnets 5 (magnetic fields of the magnets 5) are as follows (see the solid arrows in
On the other hand, when the two-row rotation switching mechanism puts the magnets 5 into a state where magnets that have the same magnetic pole arrangement are positioned completely in alignment with each other in the axial direction as two adjacent magnets 5 that are located in the first row and in the second row respectively, the magnetic fluxes from the magnets 5 (magnetic fields of the magnets 5) are as follows (see the solid arrows in
Accordingly, the heat generating apparatus according to the fifth embodiment has the same effects as the heat generating apparatus according to the first embodiment. Moreover, the two-row rotation switching mechanism employed in the fifth embodiment allows for a reduction in the entire length of the apparatus, and accordingly is effective for downsizing of the apparatus.
When the degree of action of the two-row rotation switching mechanism is controlled to put the magnets 5 into a state where magnets that have the same magnetic pole arrangement are positioned partly in alignment with each other in the axial direction as two adjacent magnets 5 that are located in the first row and in the second row respectively, the magnetic flux density of the magnets 5 reaching the heat generating drum 4A is different from that when these magnets 5 are positioned completely in alignment with each other. Thus, controlling the degree of action of the two-row rotation switching mechanism allows for adjustment of the amount of heat generation in the heat generating drum 4A, thereby resulting in adjustment of the amount of collected heat.
As in the fifth embodiment, the heat generating apparatus according to the sixth embodiment includes a two-row rotation switching mechanism as the switching mechanism that switches between a state to generate magnetic circuits between the magnets and the heat generator and a state to generate no magnetic circuits between the magnets and the heat generator. Specifically, as shown in
Out of the first and the second sections of the magnetic holding ring 6A, the first section of the magnetic holding ring 6A for the first row is fixed to the body 2. The second section of the magnetic holding ring 6A for the second row is rotatable around the rotary shaft 3. For example, a drive source such as an air cylinder, an electric actuator or the like is connected to the magnetic holding ring GA for the second row though it is not shown in the drawings. By operation of the drive source, the second section of the magnet holding ring 6A, and the second row of magnets 5 and pole pieces 9 are rotated together. Thereby, the magnets 5 can be put into a state where magnets that have the same magnetic pole arrangement are positioned completely in alignment with each other in the axial direction along the axis of the rotary shaft 3 as two adjacent magnets 5 that are located in the first row and in the second row respectively (see
In the heat generating apparatus according to the sixth embodiment, the partition wall 15 (see
In the sixth embodiment, when the two-row rotation switching mechanism puts the magnets 5 into a state where magnets that have opposite magnetic pole arrangements are positioned completely in alignment with each other in the axial direction as two adjacent magnets 5 that are located in the first row and in the second row respectively, the magnetic fluxes from the magnets 5 (magnetic fields of the magnets 5) are as follows (see the solid arrows in
On the other hand, when the two-row rotation switching mechanism puts the magnets 5 into a state where magnets that have the same magnetic pole arrangement are positioned completely in alignment with each other in the axial direction as two adjacent magnets 5 that are located in the first row and in the second row respectively, the magnetic fluxes from the magnets 5 (magnetic fields of the magnets 5) are as follows (see the solid arrows in
Accordingly, the heat generating apparatus according to the sixth embodiment has the same effects as the heat generating apparatuses according to the second and the fifth embodiments.
As in the fifth embodiment, the heat generating apparatus according to the seventh embodiment includes a two-row rotation switching mechanism as the switching mechanism that switches between a state to generate magnetic circuits between the magnets and the heat generator and a state to generate no magnetic circuits between the magnets and the heat generator. Specifically, as shown in
In the gap between the heat generating drum 4A (heat generator 4) and the primary magnets 5A, a plurality of ferromagnetic plate-shaped switches 30 are arrayed in the circumferential direction along the circumference of the rotary shaft 3 throughout the whole circumference. Unlike the array of magnets 5A and 5B and the magnet holding ring 6A, the array of switches 30 is not divided. The placement angles of the switches 30 are the same as the placement angles of the primary magnets 5A. Each of the switches 30 has the following dimensions. The dimension in the circumferential direction along the circumference of the rotary shaft 3 is nearly equal to that of each of the primary magnets 5A (see
Both ends of the respective switches 30 are held by a switch holding ring (not shown). The switch holding ring is in the shape of a cylinder that is coaxial with the rotary shaft 3, and is fixed to the body 2.
Out of the first and the second sections of the magnetic holding ring 6A, the first section of the magnetic holding ring 6A for the first row is fixed to the body 2. The second section of the magnetic holding ring 6A for the second row is rotatable around the rotary shaft 3. For example, a drive source such as an air cylinder, an electric actuator or the like is connected to the magnetic holding ring 6A for the second row though it is not shown in the drawings. By operation of the drive source, the second section of the magnet holding ring 6A and the second row of magnets 5A and 5B are rotated together. Thereby, the magnets 5A and 5B can be put into a state where magnets that have the same magnetic pole arrangement are positioned completely in alignment with each other in the axial direction along the axis of the rotary shaft 3 as two adjacent primary magnets 5A that are located in the first row and in the second row respectively and where magnets that have the same magnetic pole arrangement are positioned completely in alignment with each other in the axial direction as two adjacent secondary magnets 5B that are located in the first row and in the second row respectively (see
In the heat generating apparatus according to the seventh embodiment, the partition wall 15 (see
In the seventh embodiment, when the two-row switching mechanism puts the magnets 5A and 5B into a state where magnets that have opposite magnetic pole arrangements are positioned completely in alignment with each other in the axial direction as two adjacent primary magnets 5A that are located in the first row and in the second row respectively and where magnets that have opposite magnetic pole arrangements are positioned completely in alignment with each other in the axial direction as two adjacent secondary magnets 5B that are located in the first row and in the second row respectively, the magnetic fluxes from the magnets 5A and 5B (magnetic fields of the magnets 5A and 5B) are as follows (see the solid arrows in
On the other hand, when the two-row switching mechanism puts the first and the second rows of magnets 5A and 5B into a state where magnets that have the same magnetic pole arrangement are positioned completely in alignment with each other in the axial direction as two adjacent primary magnets 5A that are located in the first row and in the second row respectively and where magnets that have the same magnetic pole arrangement are positioned completely in alignment with each other in the axial direction as two adjacent secondary magnets 5B that are located in the first row and in the second row respectively, the magnetic fluxes from the magnets 5A and 5B (magnetic fields of the magnets 5A and 5B) are as follows (see the solid arrows in
Therefore, the heat generating apparatus according to the seventh embodiment has the same effects as the heat generating apparatuses according to the third and the fifth embodiments.
The heat generating apparatus according to the sixth embodiment includes a three-row rotation switching mechanism as the switching mechanism that switches between a state to generate magnetic circuits between the magnets and the heat generator and a state to generate no magnetic circuits between the magnets and the heat generator. Specifically, as shown in
Out of the first to the third sections of the magnetic holding ring 6A, the first and the third sections of the magnetic holding ring 6A for the first and the third rows are fixed to the body 2. The second section of the magnetic holding ring 6A for the second row is rotatable around the rotary shaft 3. For example, a drive source such as an air cylinder, an electric actuator or the like is connected to the second section of the magnetic holding ring 6A though it is not shown in the drawings. By operation of the drive source, the second section of the magnet holding ring 6A and the second row of magnets 5 and pole pieces 9 are rotated together. Thereby, the magnets 5 can be put into a state where magnets that have the same magnetic pole arrangement are positioned completely in alignment with one another in the axial direction along the axis of the rotary shaft 3 as three adjacent magnets 5 located in the first, the second and the third rows respectively (see
In the heat generating apparatus according to the eighth embodiment, the partition wall 15 (see
In the eighth embodiment, when the three-row switching mechanism puts the magnets 5 into a state where magnets that each have a magnetic pole arrangement opposite to the magnetic pole arrangement of its adjacent magnet 5 are positioned completely in alignment with one another in the axial direction as three adjacent magnets 5 located in the first, the second and the third rows respectively, the magnetic fluxes from the magnets 5 (magnetic fields of the magnets 5) are as follows (see the solid arrows in
On the other hand, when the three-row switching mechanism puts the magnets 5 into a state where magnets that have the same magnetic pole arrangement are positioned completely in alignment with one another in the axial direction as three adjacent magnets 5 located in the first, the second and the third rows respectively, the magnetic fluxes from the magnets 5 (magnetic fields of the magnets 5) are as follows (see the solid arrows in
Therefore, the heat generating apparatus according to the eighth embodiment has the same effects as the heat generating apparatus according to the sixth embodiment.
The heat generating apparatus according to the ninth embodiment includes a three-row rotation switching mechanism as the switching mechanism that switches between a state to generate magnetic circuits between the magnets and the heat generator and a state to generate no magnetic circuits between the magnets and the heat generator. Specifically, as shown in
In the gap between the heat generating drum 4A (heat generator 4) and the primary magnets 5A, a plurality of ferromagnetic plate-shaped switches 30 are arrayed in the circumferential direction along the circumference of the rotary shaft 3 throughout the whole circumference. Unlike the array of magnets 5A and 5B and the magnet holding ring GA, the array of switches 30 is not divided. The placement angles of the switches 30 are the same as the placement angles of the primary magnets 5A. Each of the switches 30 has the following dimensions. The dimension in the circumferential direction along the circumference of the rotary shaft 3 is nearly equal to that of each of the primary magnets 5 (see
Both sides of the respective switches 30 are held by a switch holding ring (not shown). The switch holding ring is in the shape of a cylinder that is coaxial with the rotary shaft 3, and is fixed to the body 2.
Out of the first to the third sections of the magnetic holding ring GA, the first and the third sections of the magnetic holding ring 6A for the first and the third rows are fixed to the body 2. The second section of the magnetic holding ring 6A for the second row is rotatable around the rotary shaft 3. For example, a drive source such as an air cylinder, an electric actuator or the like is connected to the second section of the magnetic holding ring 6A though it is not shown in the drawings. By operation of the drive source, the second section of the magnet holding ring GA and the second row of magnets 5A and 5B are rotated together. Thereby, the magnets 5A and 5B can be put into a state where magnets that have the same magnetic pole arrangement are positioned completely in alignment with one another in the axial direction along the axis of the rotary shaft 3 as three adjacent primary magnets 5A located in the first, the second and the third rows respectively and where magnets that have the same magnetic pole arrangement are positioned completely in alignment with one another in the axial direction as three adjacent secondary magnets 5B located in the first, the second and the third rows respectively (see
In the heat generating apparatus according to the ninth embodiment, the partition wall 15 (see
In the ninth embodiment, when the three-row switching mechanism puts the magnets 5A and 5B into a state where magnets that each have a magnetic pole arrangement opposite to the magnetic pole arrangement of its adjacent magnet are positioned completely in alignment with one another in the axial direction as three adjacent primary magnets 5A located in the first, the second and the third rows respectively and where magnets that each have a magnetic pole arrangement opposite to the magnetic pole arrangement of its adjacent magnet are positioned completely in alignment with one another in the axial direction as three adjacent secondary magnets 5B located in the first, the second and the third rows respectively, the magnetic fluxes from the magnets 5A and 5B (magnetic fields of the magnets 5A and 5B) are as follows (see the solid arrows in
On the other hand, when the three-row switching mechanism puts the magnets 5A and 5B into a state where magnets that have the same magnetic pole arrangement are positioned completely in alignment with one another in the axial direction along the axis of the rotary shaft 3 as three adjacent primary magnets 5A located in the first, the second and the third rows respectively and where magnets that have the same magnetic pole arrangement are positioned completely in alignment with one another in the axial direction as three adjacent secondary magnets 5B located in the first, the second and the third rows respectively, the magnetic fluxes from the magnets 5A and 5B (magnetic fields of the magnets 5A and 5B) are as follows (see the solid arrows in
Therefore, the heat generating apparatus according to the ninth embodiment has the same effects as the heat generating apparatus according to the seventh embodiment.
The present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit and scope thereof. For example, the single-row rotation switching mechanism employed in the fourth embodiment may be modified such that the magnet holding ring 6A is fixed to the body 2, while the switch holding ring holding the switches 30 is rotatable. In sum, it is required that either the magnet holding ring 6A or the array of switches 30 is rotatable around the rotary shaft 3.
The two-row rotation switching mechanism employed in the fifth to the seventh embodiments may be modified such that the second section of the magnet holding ring GA is fixed to the body 2, while the first section of the magnet holding ring 6A is rotatable. In short, it is required that either the first section or the second section of the magnet holding ring 6A is rotatable around the rotary shaft 3.
The three-row rotation switching mechanism employed in the eighth and the ninth embodiments may be modified such that the second section of the magnet holding ring 6A is fixed to the body, while the first and the third sections of the magnet holding rings 6A are rotatable. In short, it is required that either the first and the third sections of the magnet holding rings 6A or the second section of the magnet holding ring GA is rotatable around the rotary shaft 3.
In the above-described embodiments, the magnets 5 and the magnet holding ring 6A are surrounded by the heat generating drum 4A, and the magnets 5 face the inner peripheral surface of the heat generating drum 4A. However, the magnets 5 and the magnet holding ring 6A may be configured to surround the heat generating drum 4A, and the magnets 5 may face the outer peripheral surface of the heat generating drum 4A. In this case, the magnets 5 are held by the inner peripheral surface of the magnet holding ring 6A.
The heat generating apparatuses described above may be mounted not only in wind electric generating facilities but also in hydroelectric generating facilities and other power generating facilities that utilize kinetic energy of a fluid.
Further, the heat generating apparatuses described above can be mounted in vehicles (for example, trucks, buses and the like). In such a case, any of the heat generating apparatuses may be provided in a vehicle as a component separate from an eddy current decelerator serving as an auxiliary brake or alternatively may be provided in a vehicle to double as an auxiliary brake. In a case where any of the heat generating apparatuses doubles as an auxiliary brake, a switch mechanism shall be provided for switching between braking and non-braking. When any of the heat generating apparatuses is used as an auxiliary brake (decelerator), the apparatus reduces the rotational speeds of the rotary shafts such as the propeller shaft, the drive shaft and the like. Thereby, the running speed of the vehicle is controlled. In this regard, along with the generation of braking force to reduce the rotational speeds of the rotary shafts, heat is generated. The heat recovered by the heat generating apparatus mounted in the vehicle is utilized, for example, as a heat source for a heater for heating the inside of the vehicle or as a heat source for a refrigerator for refrigerating the inside of a container.
The eddy current heat generating apparatuses according to the present invention can be effectively employed in power-generating facilities utilizing kinetic energy of a fluid, such as wind electric generating facilities, hydroelectric generating facilities and the like, and in vehicles, such as trucks, busses and the like.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015-033606 | Feb 2015 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2016/055159 | 2/23/2016 | WO | 00 |
