Patent Publication Number: US-2022224212-A1

Title: Permanent magnet generator for ocean energy conversion

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a permanent generator, and more specifically, to a permanent magnet generator for ocean energy conversion. 
     2. Description of the Prior Art 
     A permanent magnet generator is provided with permanent magnets disposed on a rotor and utilizes various powers to drive the rotor to rotate relative to a stator to cause a magnetic field variation for electricity generation. However, the conventional permanent magnet generator requires a higher speed and a larger angle of a rotating movement of the rotor for electricity generation. Therefore, the conventional permanent magnet generator is not suitable for ocean energy conversion. 
     SUMMARY OF THE INVENTION 
     Therefore, it is an objective of the present invention to provide a permanent magnet generator for ocean energy conversion for solving the aforementioned problem. 
     In order to achieve the aforementioned objective, the present invention discloses a permanent magnet generator for ocean energy conversion. The permanent magnet generator includes a stator structure and a rotor structure. The stator structure includes a stator body. A plurality of stator slots is formed on the stator body. The rotor structure includes a rotor body. The rotor body is disposed inside the stator body in a swinging manner or a rotating manner. A plurality of rotor slots is formed on the rotor body. A ratio of a number of the plurality of rotor slots to a number of the plurality of stator slots is 8:9. The number of the plurality of rotor slots is at least equal to 64, and the number of the plurality of stator slots is at least equal to 72. 
     According to an embodiment of the present invention, a central axis of the stator body is coincided with a central axis of the rotor body. The plurality of stator slots are arranged along a circumferential direction of the stator body, and the plurality of rotor slots are arranged along a circumferential direction of the rotor body. 
     According to an embodiment of the present invention, each of the stator body and the rotor body is a circular column. 
     According to an embodiment of the present invention, the rotor structure further includes a plurality of permanent magnets respectively disposed inside the plurality of rotor slots, and a number of the plurality of permanent magnets is identical to the number of the plurality of rotor slots. 
     According to an embodiment of the present invention, the stator structure further includes a plurality of stator coils wrapped around the plurality of the stator slots. 
     According to an embodiment of the present invention, the stator structure further includes a shell, and the stator body is fixedly disposed inside the shell. 
     According to an embodiment of the present invention, the rotor structure further includes a connecting shaft coupled to the rotor body, and the connecting shaft passes through the shell. 
     According to an embodiment of the present invention, the stator body is formed by a plurality of silicon steel sheets. 
     According to an embodiment of the present invention, the rotor body is formed by a plurality of silicon steel sheets. 
     In summary, in the present invention, the ratio of the number of the plurality of rotor slots to the number of the plurality of stator slots is 8:9. The number of the plurality of rotor slots and the number of the plurality of stator slots are at least equal to 64 and 72 respectively. Due to the aforementioned configuration, the permanent magnet generator only requires a low speed and a small angle of a rotating movement or a swinging movement of the rotor body relative to the stator body, so as to generate electricity. In other words, in a condition of a low speed and a small angle of the rotating movement or the swinging movement of the rotor body relative to the stator body, a magnetic flux variation of the permanent magnet generator can cause the stator structure to generate an electrical current. Therefore, the present invention is suitable for the ocean energy conversion. 
     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of a permanent magnet generator according to an embodiment of the present invention. 
         FIG. 2  is a partial diagram of the permanent magnet generator according to the embodiment of the present invention. 
         FIG. 3  is a partial exploded diagram of the permanent magnet generator according to the embodiment of the present invention. 
         FIG. 4  is a partial sectional diagram of the permanent magnet generator according to the embodiment of the present invention. 
         FIG. 5  is a diagram of the permanent magnet generator in a used state according to the embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top”, “bottom”, “front”, “back”, etc., is used with reference to the orientation of the Figure (s) being described. The components of the present invention can be positioned in a number of different orientations. As such, the directional terminology is used for purposes of illustration and is in no way limiting. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive. Also, the term “connect” or “couple” is intended to mean either an indirect or direct electrical/mechanical connection. Thus, if a first device is connected to or coupled to a second device, that connection may be through a direct electrical/mechanical connection, or through an indirect electrical/mechanical connection via other devices and connections. 
     Please refer to  FIG. 1  to  FIG. 5 .  FIG. 1  is a schematic diagram of a permanent magnet generator  1  according to an embodiment of the present invention.  FIG. 2  is a partial diagram of the permanent magnet generator  1  according to the embodiment of the present invention.  FIG. 3  is a partial exploded diagram of the permanent magnet generator  1  according to the embodiment of the present invention.  FIG. 4  is a partial sectional diagram of the permanent magnet generator  1  according to the embodiment of the present invention.  FIG. 5  is a diagram of the permanent magnet generator  1  in a used state according to the embodiment of the present invention. As shown in  FIG. 1  to  FIG. 5 , the permanent magnet generator  1  includes a rotor structure  11  and a stator structure  12 . The rotor structure  11  can rotate or swing relative to the stator structure  12 . The permanent magnet generator  1  can utilize a magnetic field variation during a rotating movement or a swinging movement of the rotor structure  11  relative to the stator structure  12  to cause the stator structure  12  to generate an electrical current for electricity generation. 
     As shown in  FIG. 2  to  FIG. 4 , the stator structure  12  includes a stator body  121 , a plurality of stator coils  122  and a shell  123 . The stator body  121  is fixedly disposed inside the shell  123 . A plurality of stator slots  1211  are formed on the stator body  121 . The plurality of stator coils  122  are wrapped around the plurality of stator slots  1211  and for generating the electrical current. Preferably, the stator body  121  can be a circular column and made of magnetically conductive material, such as silicon steel. Specifically, the stator body  121  can be formed by a plurality of stacked ring-shaped silicon steel sheets. 
     The rotor structure  11  includes a rotor body  111  and a plurality of permanent magnets  112 . The rotor body  111  is disposed inside the stator body  121  in a swinging manner or a rotating manner. A plurality of rotor slots  1111  are formed on the rotor body  111 . The plurality of permanent magnets  112  are disposed inside the plurality of rotor slots  1111  respectively and configured to cause a magnetic flux variation when the rotor body  111  rotates or swings. Preferably, a number of the plurality of permanent magnets  112  can be identical to a number of the plurality of rotor slots  1111 , that is, each of the plurality of permanent magnets  112  is installed inside the corresponding rotor slot  1111 . However, in another embodiment, the number of the plurality of permanent magnets can be less than the number of the plurality of rotor slots. Preferably, the rotor body  111  can be a circular column and made of magnetically conductive material, such as silicon steel. Specifically, the rotor body  111  can be formed by a plurality of stacked ring-shaped silicon steel sheets. 
     A central axis of the stator body  121  is collided with a central axis of the rotor body  111 . The plurality of stator slots  1211  are arranged along a circumferential direction C 1  of the stator body  121 , and the plurality of rotor slots  1111  are arranged along a circumferential direction C 2  of the rotor body  111 . Preferably, the plurality of stator slots  1211  can be arranged along the circumferential direction C 1  of the stator body  121  at equal intervals, and the plurality of rotor slots  1111  can be arranged along the circumferential direction C 2  of the rotor body  111  at equal intervals. 
     It should be noticed that, in the present invention, as shown in  FIG. 4 , a ratio of the number of the plurality of rotor slots  1111  to a number of the plurality of stator slots  1211  is 8:9. Preferably, the number of the plurality of rotor slots  1111  is at least equal to 64, and the number of the plurality of stator slots  1211  is at least equal to 72. Due to the aforementioned configuration, the permanent magnet generator  1  of the present invention not only can generate electricity stably even in a condition of a low speed and a small angle of the rotating movement or the swinging movement of the rotor body  111  relative to the stator body  121  but also has better efficiency of electricity generation, which facilitates ocean energy conversion. In other words, in the condition of the low speed and the small angle of the rotating movement or the swinging movement of the rotor body  111  relative to the stator body  121 , the magnetic flux variation of the permanent magnet generator  1  still can cause the stator structure  12  to generate the electrical current. Therefore, the present invention is suitable for the ocean energy conversion. Specifically, for example, when the number of the plurality of the rotor slots  1111  and the number of the plurality of the stator slots  1211  are equal to 64 and 72, respectively, the stator coils  122  can generate the electrical current as long as the angle of the rotating movement or the swinging movement of the rotor body  111  relative to the stator body  121  reaches 22.5 degrees. Therefore, even if the rotor body  111  is driven by the waves to swing relative to the stator body  121  at a small angle back and forth instead of rotating relative to the stator body  121  along a fixed direction, the permanent magnet generator  1  still can generate electricity. Furthermore, understandably, when the number of the plurality of the rotor slots  1111  and the number of the plurality of the stator slots  1211  are greater than 64 and 72, respectively, the angle of the rotating movement or the swinging movement of the rotor body  111  relative to the stator body  121  which is required for the stator coils  122  to generate the electrical current is less than 22.5 degrees, which allows the permanent magnet generator  1  to generate electricity when the rotor body  111  is driven by the waves to swing relative to the stator body  121  at a smaller angle back and forth. 
     However, the structure of the permanent magnet generator is not limited to the aforementioned embodiment. It depends on practical demands. For example, in another embodiment, each of the rotor body and the stator body can be formed by a plurality of stacked sector-shaped silicon steel sheets. 
     Besides, as shown in  FIG. 1  to  FIG. 3  and  FIG. 5 , the rotor structure  11  further includes a connecting shaft  113  coupled to the rotor body  111 . The connecting shaft  113  passes through the shell  123  and is connected to a driving component  2 . The driving component  2  can be driven by ocean currents or waves to drive the rotor body  111  to swing relative to the stator body  121  back and forth along two opposite directions or to rotate relative to the stator body  121  along a fixed direction. Specifically, in this embodiment, the driving component  2  can be a floating component, such as a buoy. However, the present invention is not limited thereto. For example, in another embodiment, the driving component can be an impeller. 
     In summary, in the present invention, the ratio of the number of the plurality of rotor slots to the number of the plurality of stator slots is 8:9. The number of the plurality of rotor slots and the number of the plurality of stator slots are at least equal to 64 and 72 respectively. Due to the aforementioned configuration, the permanent magnet generator only requires a low speed and a small angle of a rotating movement or a swinging movement of the rotor body relative to the stator body, so as to generate electricity. In other words, in a condition of a low speed and a small angle of the rotating movement or the swinging movement of the rotor body relative to the stator body, a magnetic flux variation of the permanent magnet generator can cause the stator structure to generate an electrical current. Therefore, the present invention is suitable for the ocean energy conversion. 
     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.