JP4448994B2 - Bicycle hub dynamo - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bicycle hub dynamo that is fixed to a bicycle hub shaft and generates electric power by the rotational force of a wheel generated by traveling of the bicycle.
[0002]
[Prior art]
As shown in FIG. 10, a conventional bicycle hub dynamo 90 is arranged such that a casing 92 in which permanent magnets 91 are annularly arranged on an inner peripheral surface and magnetic pole pieces are alternately arranged in parallel in the circumferential direction. Two claw pole type stator yokes 93, 94, a core yoke 95 for magnetically coupling the stator yokes 93, 94, and a coil 96 disposed around the core yoke 95. With the magnet 91 as the outer rotor, the stator yokes 93 and 94, the core yoke 95, and the coil 96 as the inner stator, the permanent magnet 91 is rotated together with the casing 92 around the hub shaft 97 by the rotation of the wheel, and the core yoke 95 is alternated. A magnetic flux is generated, whereby a current flows through the coil 96 to generate power. In such a conventional bicycle hub dynamo 90, the casing 92 includes the inner stator and the like and constitutes a hub of a bicycle wheel, and is made by die casting, for example.
[0003]
In the casing 92, a large diameter portion 92a larger than the diameter of the stator yokes 93, 94 is formed on one end side of the hub shaft 97, and the stator yokes 93, 94 and the permanent magnet 91 are accommodated in the inner space of the large diameter portion 92a. It is disguised. On the other hand, the other end side of the casing 92 is a small diameter portion 92b (see Patent Document 1 and Patent Document 2). Further, flange portions 92c are formed at both ends of the casing 92, and spokes (not shown) are inserted into spoke holes 92d formed in the flange portions 92c.
[0004]
[Patent Document 1]
Japanese Patent No. 2991705 (FIGS. 1 and 2)
[Patent Document 2]
JP 2000-302073 A (FIGS. 1 and 2)
[0005]
However, as in the bicycle hub dynamo 90, the inner stator composed of the stator yokes 93, 94, the core yoke 95, the coil 96, and the like is arranged close to one side of the hub shaft 97 in terms of the balance of the bicycle wheel. It is not preferable. Further, since the large-diameter portion 92a is formed on one end side of the casing 92, the outer diameter of the flange 92c is set to the large-diameter portion 92 for the convenience of work for inserting and stretching the spokes. a I have to make it bigger. Therefore, there is a problem that the design of the casing 92 is limited, and the bicycle hub dynamo 90, particularly the side surface of the casing 92 has a large diameter, which increases weight and impairs the design of the bicycle.
[0006]
The present invention has been made in view of such a problem, and the degree of freedom in designing the hub casing of a bicycle hub dynamo is increased. In particular, the flanges at both ends can be reduced in diameter to improve the appearance and reduce the weight. An object of the present invention is to provide a bicycle hub dynamo that can be easily attached to a spoke.
[0007]
A bicycle hub dynamo according to the present invention has a disk part and a plurality of claw-shaped pole pieces protruding at regular intervals in the circumferential direction of the disk part, and the pole pieces are alternately arranged in the circumferential direction. An inner stator having two stator yokes combined in parallel, a core yoke that magnetically connects the two stator yokes, and a coil disposed around the core yoke is fixed to the hub shaft. A cylindrical hub casing containing the inner stator, and an outer side provided with an inner surface of the hub casing and a permanent magnet disposed in an annular shape so as to face each pole piece of the two stator yokes In a bicycle hub dynamo in which a rotor is rotatably provided on the hub axle, the hub casing has a large diameter portion at one end and a small diameter portion at the other end, and the large diameter portion and the small diameter portion. A taper is formed between And a pair of cylinder However, at the open end of each large-diameter portion, the four magnetic steels constituting the permanent magnet are fixed to the inner peripheral surface in a continuous annular shape, and the outer peripheral surface is pressed against the inner peripheral surface of the large-diameter portion. By joining the back-up rings of the joints at the open ends, both ends have a small diameter and the center is formed with a large diameter. A drum hub and a spoke hub respectively fitted to a small diameter portion of the cylindrical body, and the drum hub has an inner space in the large diameter portion where the pair of cylindrical bodies are joined together. A stator yoke, a core yoke, and a coil of an inner stator are disposed, and the spoke hub is provided so as to protrude in the radial direction of the cylindrical body, and a flange portion in which spoke holes are arranged in a circumferential direction, and the flange portion Near the center of the buttocks protrudes in the axial direction The outer peripheral surface and the inner peripheral surface of the small diameter portion are fixed to the drum hub as press contact surfaces parallel to the axis by being press-fitted into the inner peripheral surface of the circular opening end of the small diameter portion at both ends of the drum hub. It consists of a fitting part, and the flange part is an umbrella shape inclined to the inner side from the center to the periphery of the small diameter part at both ends of the drum hub, which is equal to or smaller than the large diameter part and equal to or larger than the small diameter part, And the said spoke hole is a long hole of the radial direction of this collar part, It is characterized by the above-mentioned.
[0008]
By locating the large-diameter part for accommodating the stator yoke, core yoke, etc. of the inner stator in the center, the bicycle hub dynamo is symmetrical, improving the left-right balance and increasing the strength against spoke tension. . On the other hand, by setting the diameter of the collar portion to be equal to or less than the diameter of the large diameter portion, the bicycle hub dynamo can be downsized, the appearance can be improved and the weight can be reduced. Furthermore, by making the spoke holes arranged in the circumferential direction of the collar part into a long hole in the radial direction, the spoke is inclined to the outside in the radial direction of the large diameter part of the hub casing while being inserted into the long hole. This makes it easier to install the spokes.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing an overall configuration of a bicycle hub dynamo 100 according to an embodiment of the present invention, and a lower half of the bicycle hub dynamo 100 shows a longitudinal section. The bicycle hub dynamo 100 includes two stator yokes 102L and 102R, a core yoke 103 that magnetically connects the two stator yokes 102L and 102R, and a coil 104 disposed around the core yoke 103. An inner stator is constituted by being fixed to 101, a hub casing 105 containing the inner stator, and a permanent magnet 106 arranged in an annular shape on the inner surface side of the hub casing 105 via a backup ring 109 are rotated outward. This is a so-called claw-pole generator that is rotatably provided on the hub shaft 101 as a child. The configuration of the bicycle hub dynamo 100 is merely an example, and it is of course possible to change the configuration of the inner stator or the like to a known and arbitrary configuration of a claw-pole generator.
[0010]
The bicycle equipped with the bicycle hub dynamo 100 is a known and arbitrary type used for general purposes, and the hub shaft 101 serves as a bicycle frame fork F as a front wheel or rear wheel shaft of the bicycle. In general, a sprocket is incorporated in the rear wheel, and a transmission or the like may be incorporated in the rear wheel. Therefore, it is preferable that the hub axle 101 be the axle of the front wheel of the bicycle. . When a bicycle equipped with the bicycle hub dynamo 100 is run, the bicycle wheel rotates about the hub shaft 101, the hub casing 105 rotates, and the permanent magnet 106 disposed on the inner peripheral surface thereof rotates. To do. The rotation of the permanent magnet 106 generates an alternating magnetic flux G in the stator yokes 102L and 102R and the core yoke 103, and an induced current flows through the coil 104 to generate power.
Hereinafter, each structure of an inner side stator and an outer side rotor is demonstrated in detail.
[0011]
The hub shaft 101 is a rod-shaped member made of steel or the like, and an external thread is formed on the outer peripheral surface thereof. As described above, the stator yokes 102L and 102R, the core yoke 103, and the coil 104 are fixed to the hub shaft 101 to constitute an inner stator. The material of the hub shaft 101 is not particularly limited, and a nonmagnetic material such as stainless steel may be used in addition to the steel material in order to suppress the loss of the alternating magnetic flux G.
[0012]
As shown in FIG. 1, the stator yokes 102 </ b> L and 102 </ b> R are fitted on the hub shaft 101 so as to be positioned inside the permanent magnet 106. Since the stator yoke 102L and the stator yoke 102R have the same shape, their configurations will be described below using the stator yoke 102L as an example. As shown in FIG. 2, the stator yoke 102L includes a disk portion 20L and a plurality of pole pieces 21L extending in the thickness direction of the disk portion 20L at regular intervals from the periphery of the disk portion 20L in the circumferential direction. It will be.
[0013]
The disk portion 20L is large enough to fit inside the permanent magnet 106, and its outer diameter is such that the stator yokes 102L and 102R are arranged inside the permanent magnet 106, as shown in FIG. In this case, the pole pieces 21L are set so as to be separated to the extent that the magnetic force of the permanent magnet 106 acts on the pole pieces 21L. Insertion holes 22 for inserting the hub shaft 101 are formed in the center of the disk portion 20L, and core engagement holes 23 for engagement with the core yoke 103 are provided at four locations around the insertion hole 22. Has been. In addition, the shape of the core fitting hole 23 is arbitrary, and is not limited to a rectangle as shown in the drawing, and may be a circle or a slit. The core fitting hole 23 is sufficient if it can be fitted to the core yoke 103, and is not necessarily a perforation, and may be a concave groove.
[0014]
Further, slits 24 are formed in the radial direction from four locations on the outer peripheral edge of the disk portion 20. The slit 24 is for suppressing an eddy current flowing in the circumferential direction of the disk portion 20L due to the alternating magnetic flux. Specifically, when an alternating magnetic flux is generated in the axial direction of the core yoke 103 fitted in the core fitting hole 23, an eddy current is generated around the alternating magnetic flux, that is, in the circumferential direction of the disk portion 20L. By providing the slit 24 in the flow path of the eddy current, it is difficult for the eddy current to flow in the circumferential direction of the disk portion 20L, and the generation of the eddy current is suppressed. Further, a widened portion 24a is formed in the slit 24, and this is for pulling out one end of the coil 104.
[0015]
The pole pieces 21L are provided on the outer peripheral edge of the disk portion 20L, and the pole pieces 21L extend substantially perpendicular to the thickness direction of the disk portion 20L, so that the longitudinal direction thereof is inserted into the insertion hole 22 of the disk portion 20L. It is parallel to the axial direction of the hub shaft 101. The number of pole pieces 21L to be provided on the stator yoke 102L can be arbitrarily set.
[0016]
When the two stator yokes 102L and 102R configured in this way are combined such that the pole pieces 21L and 21R are alternately arranged in parallel in the circumferential direction, and these are arranged inside the permanent magnet 106 Each of the 14 pole pieces 21L and 21R corresponds to the 28 poles of the permanent magnet 106, respectively.
[0017]
FIG. 3 shows the core yoke 103, the coil 104, and the bobbin 107. As shown in the figure, the core yoke 103 is formed by combining a pair of core yoke pieces 30, 31, and the coil 104 is wound. The bobbin 107 is accommodated in the hollow shaft 70. On the other hand, the coil 104 is wound around the outer periphery of the hollow shaft 70 of the bobbin 107, whereby the coil 104 is disposed around the core yoke 103.
[0018]
FIG. 4 is an exploded perspective view of the core yoke 103. The core yoke 103 is composed of a pair of core yoke pieces 30 and a pair of prismatic core yoke pieces 31 of the same type. It is combined in a ring so as to face each other. On both end surfaces of the core yoke pieces 30 and 31, fitting convex portions 30a and 31a that are fitted into the core fitting holes 23 of the stator yokes 102L and 102R are respectively provided so as to project. Note that the shape of the fitting protrusions 30a and 31a is arbitrary, and it is sufficient if it can be fitted to the core fitting hole 23. Further, the core yoke pieces 30 and 31 can be publicly known and have an arbitrary configuration. For example, the core yoke pieces 30 and 31 can be made of a silicon steel plate or an electromagnetic iron material, and the core yoke 103 is not made of a plurality of divided pieces. You may produce as a cylindrical integral thing using a powder sintered material.
[0019]
The bobbin 107 is made of resin for winding the coil 104. As shown in FIG. 5, a donut-shaped disk 71 is coaxially disposed at both ends of the hollow shaft 70. It is. As shown in FIG. 3, the hollow shaft 70 is configured such that the coil 104 is wound around the outer periphery thereof and the core yoke 103 is disposed in the hollow. The coil 104 wound around the hollow shaft 70 is prevented from collapsing so as to be sandwiched between both disks 71, while the core yoke 103 disposed in the hollow shaft 70 is fitted from both disks 71 to the fitting convexity. The parts 30a and 31a are fixed in a protruding state. Further, a slit 72 is formed in the disk 71 in the radial direction from the outer peripheral edge, and one end on the inner peripheral side of the coil 104 wound around the bobbin 107 can be drawn out from the slit 72. ing.
[0020]
The thus configured core yoke 103, coil 104, and bobbin 107 are assembled. As shown in FIG. 6, the hub shaft 101 is inserted into the core yoke 103, and the stator yokes 102L, 102R are inserted at both ends of the core yoke 103. The core yoke 103 magnetically couples the stator yokes 102L and 103R. 1 and FIG. 6, these are integrally held by a mounting nut 108 via a washer 80 and fixed to the hub shaft 101, and become an inner stator of the bicycle hub dynamo 100.
[0021]
In the present embodiment, the stator yokes 102L and 102R and the core yoke 103 are fitted and magnetically connected by the fitting unevenness of the core fitting 23 and the fitting protrusions 30a and 31a. The fitting irregularities are not necessarily required, and other known configurations such as magnetic connection by bringing the disk portions 20L and 20R of the stator yokes 102L and 102R into contact with the end surfaces of the core yoke 103 can be taken. is there. Further, it is preferable that the washer 80 is made of a non-magnetic material because loss of the alternating magnetic flux G generated in the stator yokes 102L and 102R and the core yoke 103 can be prevented, and the power generation efficiency can be improved.
[0022]
Next, the hub casing 105, the permanent magnet 106, and the backup ring 109 constituting the outer rotor will be described.
The hub casing 105 includes a drum hub 50 and a spoke hub 51, and the drum hub 50 includes a pair of cylindrical bodies 52 as shown in FIGS. 7 and 8, and the spoke hub 51 is attached to the cylindrical body 52. Each is fitted. The cylindrical body 52 has a large diameter portion 52a on one end side, a small diameter portion 52b on the other end side, and a tapered portion 52c formed between the large diameter portion 52a and the small diameter portion 52b. The cylindrical body 52 is joined at the large diameter portions 52a, thereby forming a cylindrical body in which the small diameter portions 52b are arranged at both ends and the large diameter portions 52a are arranged at the center. As shown in FIG. 1, the stator yokes 102 </ b> L and 102 </ b> R of the inner stator, the core yoke 103, and the coil 104 are arranged in the inner space of the large-diameter portion 52 a of the drum hub 50. The left and right shapes and weights of the bicycle hub dynamo 100 are substantially equal, and the wheels are well balanced when attached to the bicycle. In addition, the left-right symmetry increases the strength by balancing the left and right with respect to the spoke tension.
[0023]
On the other hand, the diameter of the small diameter portion 52b can be appropriately set in consideration of the dimensions of the bearing 56 and the like for rotatably providing the hub casing 105 on the hub shaft 101. In addition, by configuring the drum hub 50 from a pair of left and right cylindrical bodies 52, for example, the cylindrical body 52 can be manufactured by drawing a stainless steel plate or the like, and the manufacturing cost can be reduced compared to a conventional die-cast casing. Can be achieved.
[0024]
As shown in FIGS. 7 and 8, the spoke hub 51 includes a flange portion 53 in which spoke holes 53a are arranged in the circumferential direction, and a fitting portion 54 in which the vicinity of the center of the flange portion 53 protrudes in the axial direction. And an insertion hole 55 for inserting the hub shaft 101 is formed in the center thereof. As shown in the figure, the flange 53 has an umbrella shape that is inclined inward from the center toward the periphery in accordance with the extending direction of the spoke S. By matching the protruding direction of the flange portion 53 with the extending direction of the spoke S in this manner, the strength against the tension of the spoke S is further improved, which is preferable. Further, as shown in FIG. 7, the diameter R1 of the flange portion 53 is larger than the diameter R2 of the small diameter portion 52b of the drum hub 50 and slightly smaller than the diameter R3 of the large diameter portion 52a. As described above, the center of the drum hub 50 is the large-diameter portion 52a and both ends are the small-diameter portions 52b, so that the design of the diameter of the flange portion 53 of the spoke hub 51 can be made flexible. The diameter can be equal to or smaller than 52a. Thereby, the hub dynamo 100 for bicycles is reduced in size, and the appearance is improved and the weight is reduced.
[0025]
The spoke hole 53a is a long hole in the radial direction of the flange 53 as shown in the figure. The spokes S are inserted into the respective spoke holes 53a, whereby the spoke hub 51 and the wheel rim (not shown) are connected by the spokes S. The spoke S generally has a shape in which a fastening portion T is formed at one end of a wire-like steel material, and the vicinity of the fastening portion T is bent at a right angle, and the tip of the spoke S is substantially from the outside or the inside of the spoke hub 51. The catch portion T is locked and attached to the spoke hole 53a by being inserted through the spoke hole 53a in the horizontal direction and directed toward the wheel rim in the vicinity of the catch portion T. In this way, a plurality of spokes S are alternately inserted into the spoke holes 53a of the spoke hub 51 from the outside and the inside and pasted. By making the spoke hole 53a a long hole in the radial direction, in the installation work of the spoke S, the tip of the spoke S is placed in a substantially horizontal direction from the outside of the flange portion 53 to the spoke hole 53a as shown in FIG. When inserting, since the tip end side of the spoke S can be inclined radially outward of the large-diameter portion 52a of the drum hub 50, the spoke S is attached to the large-diameter portion 52a of the drum hub 50 in the attaching operation of the spoke S. There is no contact. On the other hand, when the tip end of the spoke S is inserted from the inside of the flange portion 53 into the spoke hole 53a in a substantially horizontal direction, the fastening portion T side of the spoke S is inclined outward in the radial direction of the large diameter portion 52a of the drum hub 50. Thus, similarly, the spoke S does not come into contact with the large diameter portion 52a of the drum hub 50. Therefore, even if the collar portion 53 has a diameter equal to or smaller than that of the large diameter portion 52a, the attachment workability of the spoke S is not impaired.
[0026]
The circumferential width of the spoke hole 53a is preferably slightly larger than the thickness of the spoke S, and it is preferable that the width of the spoke S can be locked. Further, the length of the spoke hole 53a in the radial direction needs to be increased as the spoke S is largely inclined during the mounting operation. The diameter of the large diameter portion 52a and the diameter of the flange portion 53, the drilling position of the spoke hole 53a, Considering the thickness of the flange 53, the thickness of the spoke S, etc., the spoke S can be inclined so as not to contact the large diameter portion 52a of the drum hub 50 in a state where the spoke S is inserted into the spoke hole 53a. Set as appropriate. Further, as shown in FIG. 7, if a recess 53 b is formed on the outer peripheral surface and inner peripheral surface of the flange portion 53, the portion where the peripheral edge of the spoke hole 53 a contacts the fastening portion T of the spoke S, This is preferable because the fastening portion T is well received. The insertion hole 55 is sufficiently large with respect to the hub shaft 101 in consideration of attachment of the bearing 56 and the like.
[0027]
As shown in FIG. 8, the spoke hub 51 configured in this manner is fitted by fitting the fitting portion 54 into the opening end of the small diameter portion 52 b of the drum hub 50. The opening end of the small diameter portion 52b of the drum hub 50 is circular, and its inner peripheral surface 50d is formed substantially parallel to the shaft, and the inner peripheral surface 50d is a pressure contact surface. On the other hand, the fitting portion 54 of the spoke hub 51 has a cylindrical shape protruding in the axial direction so as to be coaxial with the flange portion 53, and its outer diameter is substantially equal to the inner diameter of the opening end of the small diameter portion 52b. They are the same or slightly larger in diameter, and the outer peripheral surface 54a of the fitting portion 54 is a pressure contact surface. As shown in the figure, the fitting portion 54 of the spoke hub 51 is press-fitted into the opening end of the small diameter portion 52b of the drum hub 50, and the outer peripheral surface 54a of the fitting portion 54 and the inner peripheral surface 52d of the small diameter portion 52b are pressed against each other. Thus, the spoke hub 51 is fixed to the drum hub 50. In this way, the inner peripheral surface 52d of the small-diameter portion 52b of the drum hub 50 and the outer peripheral surface 54a of the fitting portion 54 of the spoke hub 51 are pressed against each other in parallel with the axis O of the hub casing 105. The connection strength of the spoke hub 51 increases, and in particular, the resistance against the axially outward (thrust direction) force F caused by the extension of the spoke S increases. In addition, the fitting portion 54 of the spoke hub 51 is press-fitted into the opening end of the small diameter portion 52b of the drum hub 50 and fitted, thereby simplifying the shapes of the opening ends of the fitting portion 54 and the small diameter portion 52b. When the drum hub 50 and the spoke hub 51 are made by drawing a stainless steel plate or the like, the processing becomes easy. It is of course possible to increase the fixing strength by using an adhesive or the like at the connecting portion between the drum hub 50 and the spoke hub 51.
[0028]
In the present embodiment, the hub casing 105 is composed of the drum hub 50 and the spoke hub 51 including a pair of cylindrical bodies 52. The configuration of the hub casing 105 is an example of the present invention. The hub casing 105 does not change the gist of the present invention, such that each cylindrical body 52 and the spoke hub 51 are integrally formed so that the flange portion 53 protrudes from the end of the small diameter portion 52b of the cylindrical body 52. Of course, other configurations are possible within the scope. Further, the shape of the drum hub 50 and the like is not limited to a cylindrical body, and may be a polygonal cylinder such as a hexagon or an octagon.
[0029]
The permanent magnet 106 is fixed to the inner peripheral surface of the large-diameter portion 52a at the center of the drum hub 50 of the hub casing 105 via a backup ring 109. As shown in FIG. 9, the backup ring 109 is an annular frame, and four magnetic steels constituting the permanent magnet 106 are fixed to the inner peripheral surface in a continuous annular shape. The permanent magnets 106 arranged in an annular shape are magnetized so that there are a total of 28 poles in which N and S poles alternate in the circumferential direction. Further, the backup ring 109 functions as a joint of a pair of cylindrical bodies 52 constituting the drum hub 50. Specifically, the outer diameter of the backup ring 109 is substantially the same as or slightly larger than the inner diameter of the large-diameter portion 52a of the drum hub 50. As shown in FIG. 8, each large-diameter portion 52a of the pair of cylindrical bodies 52 is provided. The cylindrical body 52 is connected by the open ends of the large-diameter portion 52a by press-fitting into the open ends of the backup ring 109 and the outer peripheral surface of the backup ring 109 and the inner peripheral surface of each large-diameter portion 52a. Thus, by connecting the pair of cylindrical bodies 52 with the backup ring 109 as a joint, the connection strength of the cylindrical bodies 52 is increased, and the resistance against the axially outer force F is increased as described above. Further, the shape of the opening end of the large diameter portion 52b can be simplified, and the processing of the drum hub 50 is facilitated. Furthermore, by using the backup ring 109 as a connection joint between the holding carrier of the permanent magnet 106 and the cylindrical body 52, the configuration of the hub casing 105 can be made simple and small in diameter.
[0030]
Such a hub casing 105 is rotatably attached to the hub shaft 101 via a bearing 56, and the permanent magnet 106 and the hub casing 105 constitute an outer rotor of the bicycle hub dynamo 100. Further, a terminal 56 for taking out the electric power of the bicycle hub dynamo 100 is projected outward from the hub casing 105. As a result, the hub casing 105 contains the inner stator, the permanent magnet 106 is annularly arranged so as to face the pole pieces 20L, 20R of the two stator yokes 102L, 102R, and the bicycle wheel is connected to the hub axle. By rotating about the axis 101, the hub casing 105 rotates and the permanent magnet 106 arranged in an annular shape on the inner peripheral surface thereof also rotates to generate an alternating magnetic flux G in the stator yokes 102L, 102R and the core yoke 103. Inductive power flows through the coil 104.
[0031]
【The invention's effect】
As described above, according to the bicycle hub dynamo according to the present invention, a small-diameter portion is formed at both ends in the axial direction, and the large-diameter portion is formed at both ends of a cylindrical body having a large-diameter portion at the center. A hub in which flanges having the same diameter or less are provided so as to protrude in the radial direction of the cylindrical body, and radial long holes for inserting the spokes are arranged in the circumferential direction in the flanges, respectively. Since it is a casing, the large-diameter part for accommodating the stator yoke, core yoke, etc. of the inner stator can be placed in the center, and the bicycle hub dynamo is symmetrical, improving the left-right balance Strength against spoke tension is also increased. On the other hand, by setting the diameter of the collar portion to be equal to or less than the diameter of the large diameter portion, the bicycle hub dynamo can be downsized, the appearance can be improved and the weight can be reduced. Furthermore, by making the hole for inserting the spoke a long hole in the radial direction of the flange portion, the spoke can be inserted while being inclined radially outward of the large diameter portion of the hub casing. It becomes easy.
[Brief description of the drawings]
FIG. 1 is a front view showing an appearance and a partial cross section of a bicycle hub dynamo 100. FIG.
2A is a front view of a stator yoke 102L, and FIG. 2B is a side view.
3A is a front view of the core yoke 103, the coil 104, and the bobbin 107, and FIG. 3B is a side view showing a partial cross section thereof.
4 is an exploded perspective view of a core yoke 103. FIG.
FIG. 5 is a perspective view of a bobbin 107. FIG.
FIG. 6 is a front view for explaining the assembly of the inner stator.
7A is a front view showing the appearance of a hub casing 105, a permanent magnet 106, and a backup ring 109 that constitute the outer rotor, and FIG. 7B is a side view thereof.
FIG. 8 is a cross-sectional view of the hub casing 105, the permanent magnet 106, and the backup ring 109 that constitute the outer rotor.
9 is a side view of the permanent magnet 106 and the backup ring 109. FIG.
10 is a longitudinal sectional view showing a schematic configuration of a conventional bicycle hub dynamo 90. FIG.
[Explanation of symbols]
100 Hub dynamo for bicycle
101 Hub axle
102L, 102R Stator yoke
103 core yoke
104 coils
105 Hub casing
106 Permanent magnet
20L, 20R disk part
21L, 21R pole piece
50 Drum hub (tubular body)
51 spoke hub
52a Large diameter part
52b Small diameter part
53a Spoke hole (long hole)
53 Buttocks

Claims (1)

Two pieces each having a disc portion and a plurality of claw-like pole pieces projecting at regular intervals in the circumferential direction of the disc portion, wherein the pole pieces are alternately arranged in parallel in the circumferential direction. A cylinder that includes a stator yoke, a core yoke that magnetically connects the two stator yokes, and a coil that is disposed around the core yoke, and is fixed to the hub axle and includes the inner stator. An outer rotor having a ring-shaped hub casing and a permanent magnet arranged in an annular shape so as to face each pole piece of the two stator yokes on the inner surface side of the hub casing. In the bicycle hub dynamo that is provided freely,
The hub casing has a pair of cylindrical bodies each having a large diameter portion formed at one end and a small diameter portion formed at the other end and a tapered portion formed between the large diameter portion and the small diameter portion. At the opening end of the part, four magnetic steels constituting the permanent magnet are fixed to the inner peripheral surface in a continuous annular shape, and a cylindrical backup ring whose outer peripheral surface is in pressure contact with the inner peripheral surface of the large-diameter portion is used as a joint. It is composed of a drum hub having both ends having a small diameter and a large diameter near the center by being joined at the open ends, and a spoke hub fitted to each of the small diameter portions of the cylindrical body. The stator yoke, the core yoke, and the coil of the inner stator are disposed in the inner space of the large-diameter portion where the pair of cylindrical bodies are joined at the large-diameter portions, and the spoke hub has a diameter of the cylindrical body. Circumferential direction provided to protrude in the direction Near the center of the flange portion and the collar portion which spoke holes are string set protrude axially, are pressed into the inner peripheral surface of the circular open end of the small diameter portion at both ends of the drum hub inner and the outer peripheral surface of the small diameter portion The peripheral surface is formed of a fitting portion fixed to the drum hub as a pressure contact surface parallel to the axis , and the flange portion is equal to or smaller than the large diameter portion at the small diameter portion at both ends of the drum hub and the same as the small diameter portion. A bicycle hub dynamo characterized in that it has an umbrella shape inclined inward from the center toward the periphery, and the spoke hole is a long hole in the radial direction of the flange.

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