Power generation device

Abstract

A power generation device (10) is provided with: a holder (33); a crankshaft (4) accommodated in the bracket (33); one or more bearings (32) that support the crankshaft (4) so as to be rotatable with respect to the bracket (33); and a stator (34) supported by the bracket (33). And a magnet (311) is fixed on the side surface of the crankshaft (4).

Description

Technical Field

[0001] This invention relates to a power generation device. Background Technology

[0002] Patent Document 1 discloses a bottom bracket structure for a bicycle with a power generation mechanism. In this bottom bracket structure, the crankshaft is connected to the rotating part of the power generation mechanism via a planetary gear unit. Under the action of the planetary gear unit, the rotating part of the power generation mechanism can rotate at a higher speed than the crankshaft.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2006-15987 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] To achieve sufficient power generation performance, the central shaft structure in Patent Document 1 incorporates a complex planetary gear unit and a power generation mechanism. This central shaft structure is costly due to its complexity. Furthermore, there are concerns about increased weight resulting from assembling the planetary gear unit and other components.

[0008] Therefore, one example of the technical problem of the present invention is to provide a power generation device that can generate electricity with a simple structure.

[0009] Solution for solving the problem

[0010] The power generation device of the first aspect of the present invention comprises: a bracket; a crankshaft housed in the bracket; one or more bearings supporting the crankshaft so as to be rotatable relative to the bracket; and a stator supported in the bracket, wherein a magnet is fixed to the side of the crankshaft.

[0011] The second aspect of the present invention provides a power generation device comprising: a crank arm; a rotor fixed to the crank arm; a bracket; a stator fixed to the bracket; a bearing; and a crankshaft supported on the bracket via the bearing. Attached Figure Description

[0012] Figure 1 This is a perspective view schematically showing the structure of the crank assembly 1 of the power generation device according to the first embodiment of the present invention.

[0013] Figure 2 This is an exploded perspective view schematically showing the structure of the crank assembly 1 of the power generation device according to the first embodiment of the present invention.

[0014] Figure 3 It is along Figure 1 A sectional view along line 3-3.

[0015] Figure 4 It is along Figure 3 A three-dimensional sectional view of the central axis 3 and crankshaft 4 of the cross section.

[0016] Figure 5 It is an exploded 3D view of the central axis 3 and the crankshaft 4.

[0017] Figure 6 This is a perspective view schematically showing the structure of the crank assembly 1A of the power generation device according to the second embodiment of the present invention.

[0018] Figure 7 This is an exploded perspective view schematically showing the structure of the crank assembly 1A of the power generation device according to the second embodiment of the present invention.

[0019] Figure 8 It is along Figure 6 A sectional view along line 8-8.

[0020] Figure 9 yes Figure 8 A partially enlarged sectional view of a portion of the sectional view.

[0021] Figure 10 It is along Figure 8 A sectional view along line 10-10.

[0022] Figure 11 This is a perspective view schematically showing the structure of the crank assembly 1B assembled with the power generation device according to the third embodiment of the present invention.

[0023] Figure 12 This is an exploded perspective view schematically showing the structure of the crank assembly 1B assembled with the power generation device of the third embodiment of the present invention.

[0024] Figure 13 It is along Figure 11 A sectional view along line 13-13.

[0025] Figure 14 It is along Figure 13 A sectional view along line 14-14. Detailed Implementation

[0026] Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings. Figure 1 This is a perspective view schematically showing the structure of the crank assembly 1 of the power generation device according to the first embodiment of the present invention. Figure 2This is an exploded perspective view schematically showing the structure of the crank assembly 1, which is assembled with the power generation device according to the first embodiment of the present invention. This crank assembly 1 is, for example, mounted to the bottom bracket 2 of the frame of a bicycle (road bike, motocross bike, mountain bike, city bike, etc.). It should be noted that... Figure 1 and Figure 2 For simplicity, only the bottom bracket 2, which has a cylindrical internal space defined in the frame, is shown in the illustration. It should be noted that the bottom bracket 2 is shown with a cylindrical shape, but it is not limited to this shape and may have other shapes.

[0027] The crank assembly 1 includes a bottom bracket 3, a crankshaft 4, a right crank arm 5, a left crank arm 6, and a chain link 7. The bottom bracket 3 is mounted to a bottom bracket 2. The interior of the bottom bracket 2 is open through circular openings 21 and 22. The crankshaft 4 is supported on the bottom bracket 3 in a manner that allows it to rotate about the x-axis. Most of the crankshaft 4 is housed within the bottom bracket 3, with one end 41 and the other end 42 protruding from the bottom bracket 3 in a direction along the x-axis (hereinafter referred to as the "rotation axis direction"). It should be noted that the crankshaft 4, the right crank arm 5, and the left crank arm 6 are, for example, made of metal.

[0028] The right crank arm 5 has a body 51, a hole 52 formed in the body 51 along the axis x, a plurality of portions (hereinafter referred to as "protrusions") 53 protruding from the body 51 in a radial direction orthogonal to the axis x, and an arm body 54 that also protrudes radially from the body 51. In this example, a chain link 7 is fitted inside the body 51 in the direction of rotation axis. During assembly, a fastening component, a bolt 72, passes through a hole 71 formed in the chain link 7 and is screwed into a threaded hole 55 formed in the protrusion 53. In this example, four threaded holes 55 and four through holes 71 are formed at predetermined angular intervals around the axis x in the right crank arm 5 and the chain link 7, respectively.

[0029] from Figure 2 As can be seen, a serrated groove 43 is formed on the outer peripheral surface of one end 41 of the crankshaft 4, and a serrated groove (not shown) is also formed on the inner peripheral surface of the mounting hole 52 of the right crank arm 5. The grooves 43 and the mounting hole 52 extend parallel to the axis x. By interlocking these grooves 43, the right crank arm 5 is mounted to one end 41 of the crankshaft 4 in a manner that prevents relative rotation. It should be noted that a mechanism (not shown) for preventing the crankshaft 4 from falling off the right crank arm 5 can also be assembled in the right crank arm 5. In addition, a pedal (not shown) is mounted at the front end of the arm body 54 extending from the base end connected to the main body 51.

[0030] On the other hand, the left crank arm 6 has an arm body 61 and a mounting hole 62 formed at the base end of the arm body 61. A serrated groove 44 is formed on the outer peripheral surface of the other end 42 of the crankshaft 4, and a serrated groove (not shown) is also formed on the inner peripheral surface of the mounting hole 62 of the left crank arm 6. These grooves 44 extend parallel to the axis x. The left crank arm 6 is mounted to the other end 42 of the crankshaft 4 in a manner that prevents relative rotation, by interlocking the grooves 44 with the grooves of the mounting hole 62. It should be noted that a mechanism (not shown) for preventing the crank 4 from detaching from the left crank arm 6 can also be assembled in the left crank arm 6. Furthermore, a pedal (not shown) is mounted at the front end of the arm body 61 extending from the base end where the mounting hole 62 is formed.

[0031] Figure 3 It is along Figure 1 A sectional view along line 3-3. Figure 4 It is along Figure 3 A three-dimensional sectional view of the central axis 3 and crankshaft 4 of the cross section. Figure 5 This is an exploded 3D view of the central axis 3 and crankshaft 4. It should be noted that... Figure 5 The record of Wutong 2 is omitted. Please refer to the following: Figures 3-5 The central shaft 3 has a rotor 31, one or more (two in this example) bearings 32, 32, a bracket 33, and a stator 34. Each bearing 32 is, for example, a ball bearing. The rotor 31 is mounted on the crankshaft 4, while the stator 34 is mounted on the bracket 33. The two bearings 32, 32 support the crankshaft 4 so that it can rotate relative to the central shaft 3. That is, the bearings 32, 32 support the rotor 31 so that it can rotate relative to the bracket 33 and the stator 34.

[0032] The rotor 31 has a magnet 311 fixed to the cylindrical outer peripheral side 45 of the crankshaft 4 centered on the axis x. For example, an adhesive is used for fixing. The magnet 311 is, for example, a permanent magnet. The magnet 311 is integrally formed into a cylindrical shape centered on the axis x. The magnet 311 is assembled to the outer peripheral side 45 by combining, for example, two or more parts divided around the axis x. In this example, the magnet 311 is embedded in a recess 46 formed on the outer peripheral side 45 of the crankshaft 4. The recess 46 is annularly recessed from the outer peripheral side 45 around the axis x.

[0033] In the radial direction, the outer diameter of the cylindrical outer peripheral side surface 311a of the magnet 311, centered on the axis x, coincides with the outer diameter of the outer peripheral side surface 45 of the crankshaft 4. In the crankshaft 4, the portion forming the recess 46 is thicker in the radial direction orthogonal to the axis x than other portions, but this is not a limitation. The portion forming the recess 46 may also be thinner than other portions, or it may have the same thickness as other portions. The outer peripheral side surface 45 of the crankshaft 4 is covered between a pair of bearings 32, 32 by a cylindrical cover 312. This cover 312 prevents the magnet 311 from falling off and ensures the axial strength of the crankshaft 4. The cover 312 is formed of a resin material such as CFRP (carbon fiber reinforced plastic).

[0034] The inner ring of bearing 32 is supported on crankshaft 4. Furthermore, the inner ring of each bearing 32 contacts either the right crank arm 5 or the left crank arm 6 in the direction of rotation. A bracket 33 is fitted onto the outer ring of bearing 32. The bracket 33 has a pair of outer peripheral sleeves (hereinafter referred to as "outer peripheral sleeves") 331, 331 and an inner peripheral sleeve (hereinafter referred to as "inner peripheral sleeve") 332. Both the outer peripheral sleeves 331 and the inner peripheral sleeves 332 are formed into a generally cylindrical shape. The outer peripheral sleeves 331, 331 are fixed to openings 21, 22 of the bottom bracket 2, respectively. Each outer peripheral sleeve 331 has a generally cylindrical portion (hereinafter referred to as "fitting portion") 331a that fits into the inner peripheral surface 23 of the bottom bracket 2 and a generally cylindrical portion (hereinafter referred to as "flange portion") 331b that protrudes radially outward from the fitting portion 331a.

[0035] The fitting portion 331a is formed in a generally cylindrical shape with the axis x as the center. A threaded groove (not shown) is cut into the outer peripheral surface of the fitting portion 331a. Similarly, a threaded groove (not shown) is cut into the inner peripheral surface 23 of the bottom bracket 2 corresponding to the fitting portion 331a. Thus, each outer peripheral sleeve 331 is assembled to the bottom bracket 2 by screwing the fitting portion 331a into the inner peripheral surface 23 of the bottom bracket 2. Each flange portion 331b is positioned adjacent to the openings 21 and 22 at a position further outward than the internal space of the bottom bracket 2. The outer ring of the bearing 32 is assembled to the inner peripheral surface of each flange portion 331b by pressing, adhesive, or the like.

[0036] On the outer peripheral surface of the flange portion 331b, grooves 331c are formed at equal angular intervals around the axis x, parallel to the axis x (see reference). Figure 4 and Figure 5In this example, multiple slots 331c are arranged at equal intervals around axis x. A tool (not shown) for removing the outer peripheral sleeve 331 from the bottom bracket 2 or assembling the outer peripheral sleeve 331 onto the bottom bracket 2 is secured in this slot 331c. The central shaft 3 is fixed to the bottom bracket 2 by tightening the threaded groove of the outer peripheral sleeve 331 into the threaded groove of the bottom bracket 2. That is, the central shaft 3 is a screw-in component. However, a press-fit central shaft that is pressed into the bottom bracket 2 can also be used instead of a screw-in type. In this case, the slots 331c and threaded grooves of the outer peripheral sleeve 331 are unnecessary.

[0037] In the direction of rotation, the end of the inner circumferential sleeve 332 is fitted into the inner end of an outer circumferential sleeve 331. In this example, the outer circumferential surface of the inner circumferential sleeve 332 is fitted into the inner circumferential surface of the fitting portion 331a of the outer circumferential sleeve 331. A sealing member 333 is sandwiched between the inner circumferential surface of the fitting portion 331a and the outer circumferential surface of the inner circumferential sleeve 332. The sealing member 333 seals the internal space of the inner circumferential sleeve 332 with respect to the external space. A recess 332a is formed on the outer circumferential surface of the inner circumferential sleeve 332, which is radially recessed inward. The stator 34 is supported on the recess 332a. In this example, the stator 34 has, for example, a cylindrical coil 341 made of copper wire, a cylindrical magnetic yoke, i.e., a stator core 342, and a stator housing 343.

[0038] Coil 341 is a so-called coreless coil, wound in the direction of rotation and formed as a ring around axis x. The internal space where coil 341 is wound is, for example, a cavity. Coil 341 is opposed to magnet 311 in the radial direction with a predetermined magnetic gap. Coil 341 is surrounded by a cylindrical stator core 342 centered on axis x. Stator core 342 surrounds crankshaft 4. Stator core 342 is formed by a laminate of multiple annular silicon steel plates stacked in the direction of rotation. A cylindrical stator housing 343 centered on axis x is disposed on the outer circumferential surface of stator core 342. In this example, stator core 342 is fitted onto the inner circumferential surface of stator housing 343. It should be noted that adhesive 344 is applied to the ends of coil 341 and stator core 342 on the left crank arm 6 side within recess 332a.

[0039] At least the crankshaft 4, rotor 31 (magnet 311), bearing 32, support 33 (outer peripheral sleeve 331 and inner peripheral sleeve 332), and stator 34 (coil 341 and stator core 342) constitute the power generation device 10 of the present invention. The power generation device 10 may further include a cover 312, a stator housing 343, or a sealing member 333. In this power generation device 10, the stator 34, i.e., the coil 341 and the stator core 342, is located between two bearings 32, 32 in the direction of rotation axis. Furthermore, the outer diameter of the outer peripheral surface of the stator 34, i.e., the stator housing 343, is set to a size smaller than or equal to the outer diameter of the outer peripheral surface of the fitting portion 331a of the outer peripheral sleeve 331 of the support 33.

[0040] The power generation device 10 has wiring (not shown) that bundles together multiple leads extending from the coils 341. This wiring extends, for example, from a through hole or slot (not shown) formed in the bracket 33 to the outside of the central axle 3, and is electrically connected to, for example, electronic equipment mounted on a bicycle. Examples of electronic equipment include lights, electric gears, electric brakes, a speedometer, and various sensors. These sensors include those capable of communicating with the speedometer using, for example, a specified wireless communication standard. The wiring extending from each coil 341 can also be connected to electronic components such as capacitors with energy storage capabilities.

[0041] When such a crank assembly 1 is assembled on a bicycle, pressing the pedal causes the right crank arm 5 and the left crank arm 6 to swing about axis x. As a result, the crankshaft 4 rotates about axis x. Through this rotation, the rotor 31 and the stator 34 rotate relative to each other. As a result, electrical energy is generated in the coil 341 through the magnetic interaction between the magnet 311 and the coil 341. The generated electrical energy is then transmitted through wiring to electronic equipment mounted on the bicycle. The electronic equipment can be driven by this electrical energy. It should be noted that the electrical energy generated by the power generation device 10 can also be temporarily stored in an energy storage device such as a capacitor.

[0042] In the crank assembly 1 described above, the power generator 10 is assembled within the bottom bracket 2. Specifically, the rotor 31 is fixed to the outer peripheral side 45 of the crankshaft 4, and the stator 34 is fixed to the bracket 33 that houses the crankshaft 4. Thus, the power generator 10 can generate electricity with a simple structure. Since the power generator 10 does not have a complex structure that could increase weight, the weight increase caused by installing the power generator 10 can be suppressed. With such a power generator 10, there is no need to carry a battery on the bicycle. The hassle of battery charging is eliminated. Furthermore, if a battery is already installed, its own weight can be reduced by decreasing its capacity. Alternatively, while keeping the battery capacity constant, the range of the electric bicycle can be increased by dedicating the power stored in the battery specifically for power assist.

[0043] Furthermore, the coil 341 of the stator 34 is a so-called coreless coil, not wound around the stator core 342. As a result, the stator 34 can be made lighter. Moreover, the generation of cogging torque caused by the magnetic interaction between the coil 341 and the magnet 311 can be suppressed. In addition, since the magnet 311 is fixed in the recess 46 formed in the outer peripheral side surface 45 of the crankshaft 4, the outer diameter of the crankshaft 4 is the same as before. Moreover, the coil 341 and the stator core 342 are located between the two bearings 32, 32, and their outer diameter is set to be below the outer diameter of the fitting portion 331a of the outer peripheral sleeve 331. Therefore, when assembling the power generation device 10, there is no need to make design changes to the existing bottom bracket 2.

[0044] Next, the scenario of attaching the crank assembly 1 to the bottom bracket 2 will be described. First, the bottom bracket 3 is attached to the bottom bracket 2. Specifically, two outer sleeves 331, each fitted with a bearing 32, are fixed to the openings 21 and 22 of the bottom bracket 2, respectively. It should be noted that an inner sleeve 332, pre-fitted with a stator 34, is supported on one of the outer sleeves 331. Then, the crankshaft 4, with a right crank arm 5 pre-fitted with a chain link 7 at one end 41, is attached to the bottom bracket 3 by insertion or other means. Then, the left crank arm 6 is attached to the other end 42 of the crankshaft 4. Thus, the crank assembly 1 is attached to the bottom bracket 2.

[0045] Figure 6 This is a perspective view schematically showing the structure of the crank assembly 1A of the power generation device according to the second embodiment of the present invention. Figure 7 This is an exploded perspective view schematically illustrating the structure of the crank assembly 1A of the power generation device according to the second embodiment of the present invention. The crank assembly 1A includes a central shaft 3A, a crankshaft 4, a right crank arm 5A, a left crank arm 6, and a chain link 7. The structures of the central shaft 3A and the right crank arm 5A differ from those of the central shaft 3 and the right crank arm 5A compared to the crank assembly 1 described above. Furthermore, the same reference numerals are used for structures identical to those in the crank assembly 1 of the first embodiment described above, and repeated descriptions are omitted here.

[0046] Figure 8 It is along Figure 6 The sectional view along line 8-8. See also... Figures 6-8 The stator 8 is fixed to the central shaft 3A adjacent to the body 51 of the right crank arm 5. Specifically, the stator 8 is fixed to the outer peripheral surface 331d of the flange portion 331b of the outer peripheral sleeve 331 of the central shaft 3. The outer peripheral surface 331d is defined, for example, by a cylindrical surface centered on the axis x. This outer peripheral surface 331d faces away from the inner peripheral surface 331e on the crankshaft 4 side. In this example, the side opposite to the crankshaft 4 side is defined as the right crank arm 5A side. That is, the stator 8 is fixed to the outer peripheral surface 331d on the right crank arm 5 side opposite to the crankshaft 4. On the other hand, the bearing 32 is fixed to the inner peripheral surface 331e on the crankshaft 4 side opposite to the right crank arm 5A.

[0047] In this stator 8, a rotor 9 is arranged opposite to the stator 8 in a radial direction orthogonal to the axis x. Specifically, as Figure 7 and Figure 8 As shown, the rotor 9 is fixed to one side of the crankshaft 4, i.e., the inner surface 51a, in the direction of the rotation axis of the main body 51 of the right crank arm 5A. In this example, the inner surface 51a extends, for example, along an imaginary plane orthogonal to the axis x. Figure 9 yes Figure 8 A partially enlarged sectional view of a portion of the sectional view. Figure 10 It is along Figure 8The sectional view along line 10-10. It should be noted that... Figure 10 For simplicity, the descriptions of the right crank arm 5A and chain link 7 have been omitted. Please refer to [the original text]. Figure 9 and Figure 10 The stator 8 has a magnetic body, namely the stator core 81, a coil 82, and an insulator 83.

[0048] The stator core 81 is formed of a laminate of silicon steel sheets or the like, which serve as magnetic materials. The stator core 81 functions as the magnetic yoke of the stator 8. The stator core 81 has a cylindrical portion (hereinafter referred to as the "cylindrical portion") 84 centered on axis x, and a plurality of teeth 85 (e.g., 18 teeth) extending radially outward from the outer circumferential surface of the cylindrical portion 84. The stator core 81 is fitted onto the outer circumferential surface 331d of the outer circumferential sleeve 331 via the inner circumferential surface 84a of the cylindrical portion 84. A coil 82 is wound around each tooth 85 in a manner having a winding axis in the radial direction. An insulator 83 is disposed between the tooth 85 and the coil 82. The insulator 83 insulates the stator core 81 from the coil 82.

[0049] The rotor 9, radially opposed to the stator 8, has a magnet 91, a yoke 92, and a housing 93. The magnet 91 is a cylindrical permanent magnet centered on the axis x. The magnet 91 can be a single cylindrical permanent magnet, or it can be multiple permanent magnets connected circumferentially to form a cylinder. The inner circumferential surface of the cylindrical magnet 91 faces the outer circumferential surface of the teeth 85 of the stator core 81 with a predetermined magnetic gap. The outer circumferential surface of the cylindrical magnet 91 is fixed to the inner circumferential surface of the generally cylindrical yoke 92 centered on the axis x, for example, by an adhesive. The yoke 92 is formed, for example, of a magnetic material.

[0050] The housing 93 has a first housing 931 disposed on the right crank arm 5A side and a second housing 932 disposed on the left crank arm 6 side. Both the first housing 931 and the second housing 932 are formed in annular shape. The first housing 931 has, for example, a flat plate portion (hereinafter referred to as "flat plate portion") 931a extending annularly along an imaginary plane orthogonal to the axis x, and a sidewall portion (hereinafter referred to as "sidewall portion") 931b extending annularly along the axis x from the outer peripheral end of the flat plate portion 931a toward the second housing 932. The first housing 931 is fixed to the inner surface 51a of the main body 51 by the flat plate portion 931a. When fixing, fastening components such as bolts (not shown) are used, for example.

[0051] The second housing 932 has, for example, a portion of a flat plate extending in a ring along an imaginary plane orthogonal to the axis x (hereinafter referred to as the "flat plate portion") 932a, and a portion of a sidewall extending in a ring along the axis x toward the first housing 931 from the outer peripheral end of the flat plate portion 932a (hereinafter referred to as the "sidewall portion") 932b. The magnetic yoke 92 is fixed to the inner peripheral surface of the sidewall portion 931b of the first housing 931 and the inner peripheral surface of the sidewall portion 932b of the second housing 932 by means of, for example, an adhesive, or the like, through its outer peripheral surface. In this way, the first housing 931 and the second housing 932 together define, for example, a ring-shaped receiving space for accommodating the stator 8.

[0052] At least the aforementioned right crank arm 5A, rotor 9, bracket 33, bearing 32, stator 8, and crankshaft 4 constitute the power generation device 10A of the second embodiment of the present invention. The power generation device 10A has a wiring (not shown) formed by bundling multiple leads extending from coil 82. This wiring is electrically connected to, for example, electronic equipment mounted on a bicycle. Examples of electronic equipment include lights, electric gears, electric brakes, a speedometer, and various sensors. Various sensors include sensors capable of communicating with the speedometer using, for example, a specified wireless communication standard. It should be noted that the wiring extending from coil 82 can also be connected to electrical components such as capacitors with energy storage functions.

[0053] With such a crank assembly 1A assembled in a bicycle, pressing the pedal causes the right crank arm 5A and the left crank arm 6 to swing about axis x. As a result, the crankshaft 4 rotates about axis x. This rotation causes the stator 8 and rotor 9 to rotate relative to each other. Consequently, electrical energy is generated in coil 82 through the magnetic interaction between magnet 91 and coil 82. This generated electrical energy is then transmitted via wiring to electronic devices mounted on the bicycle. The electronic devices can be powered by this electrical energy. It should be noted that the electrical energy generated by the generator 10A can also be temporarily stored in an energy storage device such as a capacitor.

[0054] In the crank assembly 1A described above, a power generation device 10A is assembled adjacent to the bottom bracket 2. Specifically, a stator 8 and a rotor 9 are arranged on the outside of the bottom bracket 3A, adjacent to the inner surface 51a of the right crank arm 5A. The stator 8 is fixed to the bottom bracket 3A, while the rotor 9 is fixed to the right crank arm 5A. In this way, the power generation device 10A can generate electricity with a simple structure. Since the power generation device 10A does not have a complex structure that could increase weight, the weight increase caused by installing the power generation device 10A can also be suppressed. With such a power generation device 10A, there is no need to carry a battery on the bicycle. The hassle of battery charging is eliminated. Furthermore, if a battery is already installed, the battery itself can be made lighter by reducing its capacity. Alternatively, while keeping the battery capacity unchanged, the range of the electric bicycle can be increased by dedicating the power stored in the battery to power assist.

[0055] Next, the scenario of attaching the aforementioned crank assembly 1A to the bottom bracket 2 will be described. First, the bottom bracket 3A is attached to the bottom bracket 2. Specifically, the outer peripheral sleeve 331 on the right crank arm 5A side, which is equipped with the bearing 32 and the stator 8, and the outer peripheral sleeve 331 on the left crank arm 6 side, which is equipped with the bearing 32 and the sealing member 333, are respectively fixed to the openings 21 and 22 of the bottom bracket 2. It should be noted that an inner peripheral sleeve 332 is supported by one of the outer peripheral sleeves 331. Then, the crankshaft 4, which has the chain link 7, the first housing 931, the magnet 91, and the yoke 92 pre-attached to one end 41, is attached to the bottom bracket 3A by insertion or other means. After attaching the second housing 932 to the yoke 92, the left crank arm 6 is attached to the other end 42 of the crankshaft 4. In this way, the crank assembly 1A is attached to the bottom bracket 2.

[0056] Figure 11 This is a perspective view schematically showing the structure of the crank assembly 1B assembled with the power generation device according to the third embodiment of the present invention. Figure 12 This is an exploded perspective view schematically showing the structure of the crank assembly 1B assembled with the power generation device of the third embodiment of the present invention. See also... Figure 11 and Figure 12 The crank assembly 1B includes a central shaft 3A, a crankshaft 4, a right crank arm 5B, a left crank arm 6, and a chain link 7. That is, the construction of the right crank arm 5B differs from that of the right crank arm 5A compared to the crank assembly 1A described above. Furthermore, structures identical to those in the crank assembly 1A of the second embodiment are marked with the same reference numerals, and repeated descriptions are omitted here.

[0057] Compared to the structure of the crank arm 5A in the second embodiment, specifically, in the second embodiment, the housing 931 of the rotor 9 of the crank assembly 1 is integrally formed with the right crank arm 5B. For example... Figure 12Specifically, a recess 56 for accommodating the stator 8 and rotor 9 is formed in the main body 51 of the right crank arm 5B. In this example, the recess 56 defines a flat, cylindrical accommodating space centered on the axis x. On the inner circumferential surface of the side wall 57 of the main body 51 forming the recess 56, a magnet 91 and a yoke constituting the rotor 9 are fixed.

[0058] Figure 13 It is along Figure 11 A sectional view along line 13-13. Figure 14 It is along Figure 13 The sectional view along line 14-14. See also... Figures 11-13 Similar to the second embodiment, the stator 8 is fixed to the outer peripheral surface 331d of the outer peripheral sleeve 331 of the central shaft 3A. The stator 8 has a stator core 81, a coil 82, and an insulator 83. In the radial direction, a magnet 91 fixed to the side wall 57 of the recess 56 of the main body 51 is opposed to the stator 8 with a predetermined magnetic gap.

[0059] The rotor 9 has a housing 94 covering the recess 56. The housing 94 has a flat, annular portion (hereinafter referred to as the "flat portion") 941 that is flat around the axis x and a protrusion 942 that protrudes radially from the outer periphery of the flat portion 941. A through hole 943 extending parallel to the axis x is formed in the protrusion 942. A fastening member, namely a bolt 95, passes through the through hole 943 and is screwed into a threaded hole 58 formed in the protrusion 53 of the body 51, thereby fixing the housing 94 to the right crank arm 5B. The flat portion 941 of the housing 94 covers the recess 56 around the central shaft 3A.

[0060] At least the aforementioned right crank arm 5B, rotor 9, bracket 33, bearing 32, stator 8, and crankshaft 4 constitute the power generation device 10B of the third embodiment of the present invention. In such a crank assembly 1B, the power generation device 10B is assembled adjacent to the bottom bracket 2, similar to the crank assembly 1A. Specifically, the stator 8 and rotor 9 are disposed in the recess 56 of the right crank arm 5B on the outside of the central shaft 3A. The stator 8 is fixed to the central shaft 3A, while the rotor 9 is fixed to the right crank arm 5B. Thus, the power generation device 10B can generate electricity with a simple structure.

[0061] Next, the scenario of attaching the crank assembly 1B to the bottom bracket 2 will be described. First, the bottom bracket 3A is attached to the bottom bracket 2. Specifically, the outer sleeve 331 on the right crank arm 5B side, which is equipped with the bearing 32 and the stator 8, and the outer sleeve 331 on the left crank arm 6 side, which is equipped with the bearing 32, are respectively fixed to the openings 21 and 22 of the bottom bracket 2. It should be noted that an inner sleeve 332 is supported by one of the outer sleeves 331. Then, the crankshaft 4, which has the right crank arm 5B, which is pre-equipped with the chain link 7, magnet 91, and yoke 92, at one end 41, is attached to the bottom bracket 3A by insertion or other means. After attaching the housing 94 to the right crank arm 5B, the left crank arm 6 is attached to the other end 42 of the crankshaft 4. In this way, the crank assembly 1B is attached to the bottom bracket 2.

[0062] The present invention has been described above through the above embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications or improvements can be made to the above embodiments. According to the claims, it is evident that such modifications or improvements can also be included within the technical scope of the present invention.

[0063] The embodiments described above are for the purpose of facilitating understanding of the present invention and are not intended to limit the scope of the invention. The components, their configuration, materials, conditions, shapes, and dimensions, etc., in the above embodiments are not limited to those shown in the examples and can be appropriately modified. Furthermore, within the scope of technical consistency, the components shown in different embodiments can be partially substituted or combined with each other.

[0064] Explanation of reference numerals in the attached figures

[0065] 1, 1A, 1B: Crankset; 2: Bottom bracket; 21: Opening; 22: Opening; 23: Inner circumferential surface; 3: Central shaft; 31: Rotor; 311: Magnet; 311a: Outer circumferential side; 312: Cover; 32: Bearing; 33: Bracket; 331: Outer circumferential sleeve (outer circumferential sleeve); 331a: Fitting part (fitting part); 331b: Protruding part (flange part); 331c: Groove; 331d: Outer circumferential surface; 331e: Inner circumferential surface; 332: Inner circumferential surface Side sleeve (inner circumferential sleeve); 332a: Recess; 333: Sealing component; 34: Stator; 341: Coil; 342: Magnetic yoke (stator core); 343: Stator housing; 344: Adhesive; 4: Crankshaft; 41: One end; 42: The other end; 43: Groove; 44: Groove; 45: Outer circumferential side; 46: Recess; 5: Right crank arm; 51: Body; 51a: One side (inner surface); 52: Hole (assembly hole); 53: Protruding part (protrusion) 54: Arm body; 55: Hole (threaded hole); 56: Recess; 57: Side wall; 58: Hole (threaded hole); 6: Left crank arm; 61: Arm body; 62: Hole (assembly hole); 7: Chain link; 71: Hole (through hole); 72: Bolt; 8: Stator; 81: Magnetic body (stator core); 82: Coil; 83: Insulator; 84: Cylindrical part (cylindrical section); 84a: Inner circumferential surface; 85: Tooth; 9: Rotor; 91: Magnet; 92: Magnetic 93: yoke; 931: first shell; 931a: flat plate portion (flat plate section); 931b: side wall portion (side wall section); 932: second shell; 932a: flat plate portion (flat plate section); 932b: side wall portion (side wall section); 94: shell; 941: flat plate portion (flat plate section); 942: protrusion; 943: hole (through hole); 95: fastening component (bolt); 10, 10A, 10B: power generation device; x: axis.

Claims

1. A power generation device, comprising: support; The crankshaft is housed in the bracket; One or more bearings support the crankshaft so that it can rotate relative to the bracket; and The stator is supported by the bracket. A magnet is fixed to the side of the crankshaft.

2. The power generation device according to claim 1, The stator comprises: a cylindrical magnetic yoke surrounding the crankshaft; and a cylindrical coil surrounded by the magnetic yoke.

3. The power generation device according to claim 2, The coil is formed by winding it along the axis of rotation.

4. The power generation device according to any one of claims 1 to 3, The magnet is fixed to the outer peripheral side of the crankshaft.

5. The power generation device according to any one of claims 1 to 3, The magnet is fixed to a recess on the outer peripheral side of the crankshaft.

6. The power generation device according to any one of claims 1 to 5, The power generation device includes multiple of the aforementioned bearings. In the direction of rotation, the magnet and the stator are located between the plurality of bearings.

7. A power generation device, comprising: Crank arm; The rotor is fixed to the crank arm; support; The stator is fixed to the bracket; Bearings; and The crankshaft is supported on the bracket via the bearing.

8. The power generation device according to claim 7, The rotor has a magnet.

9. The power generation device according to claim 7 or 8, The stator has a magnetic body and a coil wound around the magnetic body.

10. The power generation device according to any one of claims 7 to 9, The rotor is fixed to the crankshaft-side surface of the crank arm.

11. The power generation device according to any one of claims 7 to 10, wherein, The stator is fixed to the side of the crank arm of the bracket.

12. The power generation device according to any one of claims 7 to 11, wherein, The bearing is fixed to the crankshaft side of the bracket.

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