Generators and power generation equipment

Abstract

To improve the energy conversion efficiency of generators. [Solution] The generator according to this embodiment is a generator having a rotating shaft, a rotor composed of permanent magnets arranged around the rotating shaft, and a stator composed of coils arranged around the rotor. The rotor has a base arranged around the rotating shaft, the permanent magnets arranged on the outer circumference of the base, and a magnetic material layer arranged between the permanent magnets and the base. The rotating shaft is formed in a pipe-shaped hollow structure. The magnetic material layer is formed from a plate-shaped material having openings.

Description

Technical Field

[0001] Embodiments of the present invention relate to a generator and a power generation device.

Background Art

[0002] A generator has a structure in which a rotor is disposed around a rotating shaft and a stator is disposed around the rotor. A power generation device generates an electric current in a coil forming the rotor or the stator of the generator by rotating the rotating shaft of the generator with a drive motor (a propeller in the case of wind power generation). The cylindrical rotating shaft is formed of a thick iron material or the like because a large force is applied to support the force due to the rotational movement from the drive motor and the loads of the rotor and the stator.

[0003] When the rotor of the generator is formed of a coil, it is necessary to provide a brush to extract the current generated in the coil. In this case, a spark is generated when the rotating coil contacts the brush, resulting in energy loss. In the case of a brushless motor in which the rotor is formed of a permanent magnet, the energy loss due to the generation of a spark can be suppressed. When the rotor is formed of a permanent magnet, a magnetic material layer formed by laminating silicon steel sheets is often provided between the rotating shaft and the permanent magnet in order to strengthen the magnetic field lines.

[0004] However, the cylindrical rotating shaft and the magnetic material layer formed of silicon steel sheets are heavy, which is a factor increasing the weight of the rotor. The heavier the rotor, the more energy is required to rotate the rotor, so the energy conversion efficiency of the generator decreases. In addition, mounting a heavy generator on a vehicle deteriorates the fuel efficiency of the vehicle. Also, mounting a heavy generator on a flying object such as a drone shortens the flight time.

[0005] There are also rotating electrical machines using a thin magnetic material layer, but it is hard to say that the weight reduction of the rotor is sufficient from the viewpoint of improving the energy conversion efficiency of the rotating electrical machine by reducing the weight of the rotor.

Prior Art Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2024-53402 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] This invention was made under the circumstances described above, and aims to improve the energy conversion efficiency of a generator by reducing the weight of the generator's rotor or rotating shaft. [Means for solving the problem]

[0008] A generator according to an embodiment for solving the above problems is a generator having a rotating shaft, a rotor composed of permanent magnets arranged around the rotating shaft, and a stator composed of coils arranged around the rotor. The rotor has a base arranged around the rotating shaft, the permanent magnets arranged on the outer circumference of the base, and a magnetic material layer arranged between the permanent magnets and the base. The rotating shaft is formed in a pipe-shaped hollow structure. The magnetic material layer is formed from a plate-shaped material having openings. [Brief explanation of the drawing]

[0009] [Figure 1] This is a diagram illustrating the configuration of a power generation device according to an embodiment. [Figure 2] This is a perspective view of the generator according to the embodiment. [Figure 3] This is a diagram showing the configuration of the generator according to the embodiment. [Figure 4] This is a diagram illustrating the rotating shaft of a generator according to an embodiment. [Figure 5] This is a diagram illustrating the magnetic material layer of a generator according to an embodiment. [Figure 6] This is a diagram illustrating the output characteristics of the generator according to the embodiment. [Figure 7]This diagram illustrates the connection between the drive motor and the generator according to the embodiment. [Figure 8] This diagram illustrates the connection between the drive motor and the generator according to the embodiment. [Figure 9] This is a diagram illustrating the air cooling effect of the generator according to this embodiment. [Figure 10] This is a diagram illustrating the magnetic material layer of a generator according to an embodiment. [Figure 11] This is a diagram illustrating the magnetic material layer of a generator according to an embodiment. [Modes for carrying out the invention]

[0010] This embodiment will be described below with reference to the drawings. For the purposes of this description, an XYZ coordinate system consisting of mutually orthogonal X, Y, and Z axes will be used as appropriate.

[0011] Figure 1 is a diagram showing the configuration of the power generation device 100 according to this embodiment. The power generation device 100 comprises a drive motor 110 and a generator 10. The drive motor 110 is located on the upper part (+Z side) of the base case 120, and the generator 10 is mounted inside the base case 120. The generator 10 is fixed inside the base case 120 by a fixing member 130 so as not to shift in the X and Y axis directions. The fixing member 130 is made of a light material such as plastic (including expanded polystyrene) or carbon.

[0012] The base case 120 is a case consisting of a top surface 121, a side surface 122, and a bottom surface 123. The shape of the base case is, for example, a rectangular parallelepiped or a cylindrical shape. The base case 120 has a shelf 124 inside for mounting the generator 10. A through hole 1211 is provided in the center of the top surface 121 for inserting the rotating shaft 111 of the drive motor 110 into the base case 120. By inserting the rotating shaft 111 of the drive motor 110 through the through hole 1211 into the inside of the base case 120, the rotating shaft 111 of the drive motor 110 is positioned so that its longitudinal direction is vertical (Z-axis direction). The diameter of the through hole 1211 is formed to be slightly larger than the diameter of the rotating shaft 111 of the drive motor 110. In addition, a recess 1231 is formed in the center of the bottom surface 123 of the base case 120.

[0013] The base case 120 should be as light as possible. The required strength of the base case 120 is sufficient to support the load of the drive motor 110 and the generator 10. The base case 120 is made of, for example, aluminum, carbon, or plastic. To reduce the weight of the base case, the top surface 121, sides 122, and shelves 124 may be made of, for example, a mesh structure or a lattice structure. Also, if the base case 120 is ventilated, the heat generated by the generator 10 can be dissipated to the outside of the base case 120, thereby improving the heat dissipation effect. Furthermore, if the base case is made of a material with a low specific heat, such as aluminum, the heat dissipation effect can be improved.

[0014] The drive motor 110 rotates using a DC power supply (for example, 48V DC, 24V DC) or an AC power supply (for example, 100V AC, 200V AC) as its power source, and rotates the rotating shaft 20 of the generator 10.

[0015] The generator 10 rotates based on the rotation of the drive motor 110 and outputs AC power. Figure 2 is a perspective view of the generator 10. In the case of the generator 10 shown in Figure 2, the rotation of the rotating shaft 20 by the drive motor 110 (not shown in Figure 2) outputs three-phase three-wire AC power to terminals 41a, 41b, and 41c.

[0016] FIG. 3 is a configuration diagram of the generator 10. The generator 10 includes a rotating shaft 20 that rotates by the rotational movement of a drive motor 110, a rotor 30 disposed around the rotating shaft 20, and a stator 40 disposed around the rotor 30. The stator 40 is fixed to the inner wall of the exterior 50, and the exterior 50 does not rotate.

[0017] The rotating shaft 20 protrudes in the Z-axis direction from the exterior 50 that covers the rotor 30 and the stator 40. The rotating shaft 20 is formed in a pipe-shaped hollow structure, and a cavity 21 exists inside the rotating shaft 20. The rotating shaft 20 has a through hole 22 that penetrates from the outer periphery to the inner periphery of the rotating shaft 20.

[0018] FIG. 4 is an example of the through hole 22 provided in the rotating shaft 20. As shown in FIG. 4, the through hole 22 is formed obliquely (for example, approximately 45 degrees) from the outer periphery to the inner periphery of the rotating shaft 20 with respect to the longitudinal direction (Z-axis direction) of the rotating shaft 20. Also, the through hole 22 is formed obliquely (for example, approximately 45 degrees) from the outer periphery to the inner periphery of the rotating shaft 20 with respect to the rotational direction (X-axis or Y-axis direction) of the rotating shaft 20. That is, the through hole 22 is formed obliquely with respect to the X-axis, Y-axis, and Z-axis.

[0019] The rotating shaft 20 is formed to protrude from the exterior 50 that covers the rotor 30 and the stator 40. The through hole 22 formed in the portion not covered by the exterior 50 is formed obliquely in the direction from the portion not covered by the exterior 50 to the portion covered by the exterior 50. In FIG. 3, from one end (+Z side, left end) of the rotating shaft 20 to the right end of the exterior 50, the through hole 22 is formed obliquely in the -Z direction from the outer periphery to the inner periphery of the rotating shaft 20. Also, from the right end of the exterior 50 to the other end (-Z side, right end) of the rotating shaft 20, the through hole 22 is formed obliquely in the +Z direction from the outer periphery to the inner periphery of the rotating shaft 20.

[0020] The size of the through-hole 22 opening is determined by considering the air cooling effect (amount of air flowing through the cavity 21) caused by the air flowing through the cavity 21 within the through-hole 22. If the opening is too large, the velocity of the air flowing through the cavity 21 may decrease. For example, the size of the through-hole 22 opening on the outside of the exterior 50 may be larger than the size of the through-hole 22 opening inside the exterior 50.

[0021] A protrusion 26 is formed at the +Z end of the rotating shaft 20. The -Z end of the rotating shaft 20 is formed in a conical shape (with a rounded tip).

[0022] The rotor 30 is composed of a permanent magnet 31, a base 32, and a magnetic material layer 33. The base 32 is mounted around the rotating shaft 20, and the permanent magnet 31 is arranged on the outer circumference of the base 32. The magnetic material layer 33 is placed between the permanent magnet 31 and the base 32. To prevent the permanent magnet 31 from being scattered by centrifugal force, a scattering prevention tube may be provided around the outer circumference of the permanent magnet 31. The scattering prevention tube is preferably made of a light material such as aluminum or plastic. Alternatively, the permanent magnet 31 may be fixed with rubber or tape instead of a scattering prevention tube.

[0023] The permanent magnet 31 can be made of, for example, ferrite, neodymium, or samarium-cobalt, but a lightweight and strong magnetic material is preferred. The base 32 is a component that adjusts the distance between the permanent magnet 31 and the coil of the stator 40, and also fixes the permanent magnet 31 and the magnetic material layer 33 to the rotating shaft 20. It is desirable that the base 32 be made of a lightweight material that is heat resistant and does not deform. For example, the base 32 is made of plastic or a carbon-containing resin. The base 32 may also be made of thin and lightweight aluminum or ceramic. Since the base 32 is made of a hollow structure, a cavity 35 is formed between the rotating shaft 20 and the magnetic material layer 33.

[0024] The magnetic material layer 33 is a component for reinforcing magnetic field lines. As shown in Figure 5, the magnetic material layer 33 is a plate-shaped material with openings 331 and is formed in a pipe shape. In the example shown in Figure 5, the openings 331 are formed by a plurality of circular holes. The magnetic material layer 33 is made of a material with high magnetic susceptibility, such as iron or silicon steel plate, with a plate thickness of 1 mm or less.

[0025] The stator 40 is composed of coils. The stator 40 is positioned on the inner wall of the casing 50. As shown in Figure 1, the casing 50 is fixed to the base case 120. The coils forming the stator 40 are arranged so that the magnetic field formed by the permanent magnet 31 winds around and penetrates the coils. Although not shown in Figure 3, the ends of the coils are connected to terminals 41a, 41b, and 41c as shown in Figure 2.

[0026] As shown in Figure 3, the distance in the X-axis direction between the permanent magnet 31 and the stator 40 is approximately 3 mm to 5 mm for small motors where the length of the rotor 30 in the X-axis direction is 10 cm or less. Generally, this distance is set to the limit where the rotor and stator do not come into contact (for example, 1 mm or less). However, if the distance between the rotor and stator is too short, the electromagnet formed by the current flowing through the coils of the stator 40 and the permanent magnet 31 of the rotor 30 attract each other, thereby absorbing rotational energy from the rotating shaft 20 and the rotor 30, and reducing the energy conversion efficiency of the generator 10. On the other hand, if the distance between the rotor 30 and the stator 40 is too large, the strength and amount of magnetic flux passing through the coils of the stator 40 decreases, so the power output of the generator 10 decreases. In other words, as shown in Figure 6, there is an optimal distance between the rotor 30 and the stator 40 from the viewpoint of the power generation efficiency of the generator 10. This optimal distance is determined according to the size, shape, etc., of the generator 10.

[0027] Returning to Figure 1, the rotating shaft 20 of the generator 10 is positioned so that its longitudinal direction is vertical (Z-axis). The rotating shaft 20 of the generator 10 is connected to the rotating shaft 111 of the drive motor 110. The -Z end of the rotating shaft 20 of the generator 10 is positioned to be in the recess 1231 of the bottom surface 123 of the base case 120.

[0028] Figures 7 and 8 illustrate the connection between the drive motor 110 and the generator 10. For example, a recess 112 is formed on the -Z end of the rotating shaft 111 of the drive motor 110 (see Figure 1), as shown in Figure 7. Also, for example, a protrusion 26 is formed on the +Z end of the rotating shaft 20 of the generator 10 (see Figure 1), as shown in Figure 8. By engaging the protrusion 26 of the rotating shaft 20 of the generator 10 with the recess 112 of the rotating shaft 111 of the drive motor 110, the rotating shaft 20 of the generator 10 is connected to the rotating shaft 111 of the drive motor 110, and the rotating shaft 20 of the generator 10 rotates in conjunction with the rotation of the rotating shaft 111 of the drive motor 110.

[0029] Next, the operation of the power generator 100 will be described. The magnetic field formed by the permanent magnets 31 that make up the rotor 30 is reinforced by the magnetic material layer 33. The magnetic field formed by the permanent magnets 31 penetrates the coils that form the stator 40 in a winding manner. The rotating shaft 20 of the generator 10 rotates in conjunction with the rotation of the rotating shaft 111 of the drive motor 110. As the rotating shaft 20 of the generator 10 rotates, the rotor 30 rotates around the rotating shaft 20 as its axis of rotation. As the rotating shaft 20 rotates, the magnetic field of the permanent magnets 31 that penetrate the coils that form the stator 40 in a winding manner changes, and a current is generated in the coils that form the stator 40 according to Fleming's rule. The generated current is output to terminals 41a, 41b, and 41c shown in Figure 2, and three-phase three-wire AC power is output to terminals 41a, 41b, and 41c.

[0030] Figure 9 is a diagram illustrating the air cooling effect of the generator 10 according to this embodiment. When the generator 10 generates electricity, current flows through the coils forming the stator 40, generating heat due to the resistance of the coils. In addition, the temperature of the rotating shaft 20 rises due to frictional heat generated as the rotating shaft 20 rotates. As the temperatures of the stator 40 and the rotating shaft 20 rise, the temperature of the air inside the casing 50 also rises.

[0031] As shown by the dotted line in Figure 9, the low-temperature air surrounding the outer casing 50 flows into the cavity 21 of the rotating shaft 20 through a through-hole 22 located on the upper side of the outer casing 50 (the +Z side of the outer casing 50). The through-hole 22 is formed at an angle (for example, approximately 45 degrees) to the longitudinal direction (Z-axis direction) and rotational direction (X-axis or Y-axis) of the rotating shaft. Because the through-hole 22 is formed at an angle to the rotational direction, the airflow accompanying the rotation hits the side of the through-hole 22, increasing the amount of air introduced into the cavity 21. Also, because the through-hole 22 is formed at an angle (for example, approximately 45 degrees) to the longitudinal direction (Z-axis direction) of the rotating shaft, the flow velocity in the -Z direction of the air that has flowed into the cavity 21 increases, improving the circulation of air passing through the cavity 21. The high-temperature rotating shaft 20 is cooled by dissipating heat into the air in the cavity 21. Because the airflow in the cavity 21 is fast, the air cooling effect is large.

[0032] Furthermore, the hot air inside the outer casing 50 and the cavity within the base 32 flows into the cavity 21 of the rotating shaft 20 through the through hole 22 provided in the rotating shaft 20 inside the outer casing 50. Because the through hole 22 is formed at an angle (for example, approximately 45 degrees) to the longitudinal direction (Z-axis direction) of the rotating shaft, the flow velocity in the -Z direction of the air that flows into the cavity 21 increases, improving the circulation of air passing through the cavity 21.

[0033] The hot air inside the cavity 21 flows out through the through-hole 22 on the -Z side of the outer casing 50 into the space inside the base case 120, replacing the cooler air inside the base case 120. The rising air inside the base case 120 is then dissipated to the outside of the power generator 100 through the gaps in the mesh structure of the base case 120, replacing the cooler air outside the power generator 100. This repeated air circulation suppresses the temperature rise of the generator 10.

[0034] As described above, the generator 10 and power generation device 100 according to the embodiment reduce the weight of the rotating shaft 20 by forming the rotating shaft 20 of the generator 10 into a pipe-shaped hollow structure and further forming a magnetic material layer 33 with a thin plate-shaped material having an opening. By reducing the weight of the rotating shaft 20, the energy conversion efficiency of the generator 10 can be improved.

[0035] Furthermore, the generator 10 and power generation device 100 according to this embodiment further reduce the weight of the rotor 30 by making the base 32 of the rotor 30 of the generator 10 a hollow structure. This makes it possible to further improve the energy conversion efficiency of the generator 10.

[0036] Furthermore, the generator 10 according to this embodiment has through holes 22 that penetrate from the outer circumference to the inner circumference of the rotating shaft 20, which is formed in a pipe-shaped hollow structure. The through holes 22 are formed at an angle from the outer circumference to the inner circumference of the rotating shaft 20 with respect to the longitudinal direction (Z-axis direction) of the rotating shaft 20. Also, the through holes 22 are formed at an angle from the outer circumference to the inner circumference of the rotating shaft 20 with respect to the rotation direction (X-axis or Y-axis direction) of the rotating shaft 20. In addition, the through holes 22 formed in the part not covered by the outer casing 50 are formed at an angle from the part not covered by the outer casing 50 toward the part covered by the outer casing 50. By forming the through holes 22 at an angle with respect to the longitudinal direction and rotation direction of the rotating shaft, the amount of air flowing into the cavity 21 inside the rotating shaft 20 is increased, and the speed of the air flowing inside the cavity 21 is increased. By making the through holes 22 in this way, the air cooling effect can be enhanced, and the temperature rise of the generator 10 can be suppressed. Furthermore, by providing a through hole 22 in the rotating shaft 20, the weight of the rotating shaft 20 can be further reduced, thereby improving the energy conversion efficiency of the generator 10.

[0037] As shown in Figure 1, the load of the drive motor 110 is supported by the base case 120. The load of the stator 40 and casing 50 of the generator 10 is supported by the shelf 124 of the base case 120. Since the longitudinal directions of the rotating shaft 111 of the drive motor 110 and the rotating shaft 20 of the generator 10 are perpendicular, the load of the drive motor 110 and the stator 40 of the generator 10 does not act on the rotating shaft 20 of the generator 10. Therefore, the required specifications for the strength of the rotating shaft 20 in the vertical direction (Z-axis direction in Figure 1) can be reduced. Also, since the rotating shaft 20 is long in the vertical direction (Z-axis direction in Figure 1), it has a large vertical load capacity. Therefore, the thickness of the pipe-shaped rotating shaft 20 (thickness in the X-axis and Y-axis directions in Figure 1) can be reduced, and the weight of the rotating shaft 20 can be reduced, thereby improving the energy conversion efficiency of the generator 10.

[0038] Furthermore, the rotating shaft 20 of the generator 10 rotates around its centerline. The weight of the rotating shaft 20 itself is applied in the Z-axis direction in Figure 1. Therefore, the rotating shaft 20 is not subjected to loads (excluding rotational torque) in the X-axis and Y-axis directions in Figure 1. Consequently, the required strength specifications for the rotating shaft 20 in the X-axis and Y-axis directions in Figure 1 can be reduced compared to when the drive motor 110 and the generator 10 are connected horizontally. As a result, the thickness of the pipe-shaped rotating shaft 20 (thickness in the X-axis and Y-axis directions in Figure 1) can be reduced, and the weight of the rotating shaft 20 can be reduced, thereby improving the energy conversion efficiency of the generator 10.

[0039] In the above explanation, Figures 7 and 8 were used as examples to describe the case in which the rotating shaft 111 of the drive motor 110 and the rotating shaft 20 of the generator 10 are joined together. However, the method of joining the rotating shaft 111 of the drive motor 110 and the rotating shaft 20 of the generator 10 is not limited to these. For example, the rotating shaft 111 of the drive motor 110 and the rotating shaft 20 of the generator 10 may be joined by welding. Alternatively, the rotating shaft 111 of the drive motor 110 and the rotating shaft 20 of the generator 10 may be joined using connecting fittings or the like. Furthermore, the rotating shaft 111 of the drive motor 110 and the rotating shaft 20 of the generator 10 may be configured as a single rotating shaft.

[0040] Furthermore, the above explanation described the case where the rotating shaft 111 of the drive motor 110 and the rotating shaft 20 of the generator 10 are directly coupled, but it is not necessary to limit the coupling between the two to direct coupling. For example, they may be coupled indirectly using gears or the like. In this case, the load of the rotating shaft 111 of the drive motor 110 being applied to the rotating shaft 20 of the generator 10 can be eliminated, but it is likely that the load applied to the rotating shaft 20 of the generator 10 in the direction of rotation (X-axis and Y-axis direction) will increase.

[0041] Furthermore, while the above explanation described the case where the rotating shaft 20 of the generator 10 is rotated by a drive motor 110, the power source for rotating the rotating shaft 20 of the generator 10 is not limited to a drive motor. For example, the rotating shaft 20 of the generator 10 may be rotated by the rotation of a propeller powered by hydraulics. Alternatively, the rotating shaft 20 of the generator 10 may be rotated using the power of a turbine powered by thermal or nuclear energy.

[0042] Furthermore, although the above explanation described the case where the magnetic material layer 33 is formed from an iron or silicon steel sheet with a thickness of 1 mm or less, the thickness of the magnetic material layer 33 should be determined by considering the balance of the magnetic force strength of the permanent magnet 31, the required magnetic field strength formed by the rotor 30, the conditions of the stator 40 coils, the required power output specifications of the generator 10, and the weight of the generator 10.

[0043] Furthermore, although the above explanation described the case in which the load of the generator 10 is supported by the shelf 124 of the base case 120, the method of supporting the load of the generator 10 is not limited to this. For example, the generator 10 may be fixed to the side 122 of the base case 120 with metal fittings or the like. In this case, the fixing material 130 is not necessary.

[0044] (Variation 1) In the above explanation using Figure 5, the case in which multiple circular holes are provided as the openings 331 in the magnetic material layer 33 was described. However, the shape of the openings 331 is not limited to circular holes. The purpose of providing the openings 331 in the magnetic material layer 33 is to reduce the weight of the magnetic material layer 33. Therefore, the openings 331 provided in the magnetic material layer 33 may be, for example, a mesh structure as shown in Figure 10, or a lattice structure as shown in Figure 11.

[0045] (Modification 2) The above description describes a case where the through hole 22 is formed at an angle with respect to the longitudinal direction of the rotation axis 20 (the Z-axis direction in Figure 4), and also at an angle with respect to the rotation direction of the rotation axis 20 (the X-axis or Y-axis in Figure 3). As a modification, the through hole 22 may be formed at an angle with respect to the longitudinal direction of the rotation axis 20 (the Z-axis direction in Figure 4), but not at an angle with respect to the rotation direction of the rotation axis 20 (the X-axis or Y-axis in Figure 4).

[0046] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0047] 10…Generator 20…Rotation axis 21...Cavity 22…Through hole 26…Convex part 30... Rotor 31…Permanent magnet 32... Pedestal 33...Magnetic material layer 331…Aperture 35...Cavity 41a, 41b, 41c... terminals 50…Exterior (case) 100... Power generation device 110…Drive motor 111... Rotation axis of the drive motor 112…recess 120...Base case 121... Top surface of the base case 1211... Through hole 122... Side of the base case 123...Bottom of the display case 1231…recess 124... Shelf of the display case 130…Fixing material

Claims

1. A generator having a rotating shaft, a rotor composed of permanent magnets arranged around the rotating shaft, and a stator composed of coils arranged around the rotor, The rotor comprises a base arranged around the rotating shaft, a permanent magnet arranged on the outer circumference of the base, and a magnetic material layer arranged between the permanent magnet and the base. The aforementioned rotating shaft is formed in a pipe-shaped hollow structure. The magnetic material layer is formed of a plate-shaped material having an opening. Generator.

2. The magnetic material layer is formed from an iron, silicon steel plate, or ferrite plate with a thickness of 1 mm or less. The generator according to claim 1.

3. The aforementioned base is formed in a hollow structure. The generator according to claim 1.

4. The base is made of plastic or resin. The generator according to claim 3.

5. The rotating shaft has a through hole that penetrates from the outer circumference to the inner circumference, The through hole is formed at an angle to the longitudinal direction of the rotation shaft, from the outer circumference to the inner circumference of the rotation shaft. The generator according to claim 1.

6. The through hole is formed at an angle from the outer circumference to the inner circumference of the rotating shaft with respect to the rotational direction of the rotating shaft. The generator according to claim 5.

7. The rotating shaft is formed to protrude from the outer casing covering the rotor and the stator, The through-hole formed in the portion not covered by the exterior is formed at an angle in the direction from the portion not covered by the exterior toward the portion covered by the exterior. The generator according to claim 5.

8. The distance between the rotor's permanent magnet and the stator's coil is 3 mm to 5 mm. The generator according to claim 1.

9. The drive motor and A generator according to any one of claims 1 to 8, A power generation device having the following features.

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