JP2016158421A - Dynamo for bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dynamo for bicycle, capable of improving a power generation efficiency.SOLUTION: The dynamo for bicycle includes: a supporter; a rotor which is mounted to be rotatable around a rotational axis to the supporter and whose rotation is input from the outside; a coil supported on the supporter; a yoke supported on the supporter; and a first magnet and a second magnet rotatable around the rotational axis together with the rotor. The yoke includes a magnet opposing part disposed between the first magnet and the second magnet.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bicycle generator.

  2. Description of the Related Art Conventionally, a bicycle generator that is mounted on a bicycle and generates power when the bicycle is driven is known (for example, Patent Document 1).

Japanese Patent No. 5357937

Bicycle generators are required to improve power generation efficiency in order to reduce the weight of bicycles or increase power consumption based on the electrification of bicycle components.
An object of the present invention is to provide a bicycle generator capable of improving power generation efficiency.

  [1] An embodiment of the bicycle generator according to the present invention includes a support, a rotating body that is rotatable about a rotation axis with respect to the support, and the rotation is input from the outside. A coil supported by the support, a yoke supported by the support, and a first magnet and a second magnet that can rotate about the rotation axis together with the rotating body, wherein the yoke includes the first magnet And a magnet facing portion disposed between the second magnet and the second magnet.

[2] According to one embodiment of the bicycle generator, the first magnet and the second magnet are not relatively rotatable.
[3] According to one embodiment of the bicycle generator, the yoke further includes a main body part that is partially disposed between the first magnet and the coil.

[4] According to one embodiment of the bicycle generator, the magnet facing portion does not overlap the coil when viewed from a direction orthogonal to the rotation axis direction.
[5] According to one embodiment of the bicycle generator, the magnet facing portion is located on the outer side in the rotational axis direction than the coil.

  [6] According to one embodiment of the bicycle generator, the first magnet includes a plurality of magnetic poles arranged in the circumferential direction, and the second magnet includes a plurality of magnetic poles arranged in the circumferential direction, The number of magnetic poles of the first magnet and the number of magnetic poles of the second magnet are the same, and the phase of the magnetic pole of the first magnet and the phase of the magnetic pole of the second magnet are shifted by a predetermined angle.

[7] According to one embodiment of the bicycle generator, the predetermined angle is within a range of 15% to 30% with respect to a phase width of one magnetic pole of the first magnet and the second magnet. is there.
[8] According to one embodiment of the bicycle generator, the predetermined angle is within a range of 18% to 20% with respect to a phase width of one magnetic pole of the first magnet and the second magnet. is there.

  [9] According to one embodiment of the bicycle generator, the first magnet includes a plurality of magnetic poles arranged in the circumferential direction, and the second magnet includes a plurality of magnetic poles arranged in the circumferential direction, The number of magnetic poles of the first magnet is the same as the number of magnetic poles of the second magnet, and the phase of the magnetic poles of the first magnet and the phase of the magnetic poles of the second magnet are substantially the same.

[10] According to an embodiment of the bicycle generator, the bicycle generator further includes a positioning mechanism that positions phases of the first magnet and the second magnet with respect to the rotating body.
[11] According to one aspect of the bicycle generator, the yoke includes a first yoke and a second yoke, the first yoke includes a first magnet facing portion, and the second yoke. The yoke includes a second magnet facing portion, and the first magnet facing portion and the second magnet facing portion constitute the magnet facing portion.

[12] According to one embodiment of the bicycle generator, the first yoke is composed of a plurality of first yoke pieces, and the second yoke is composed of a plurality of second yoke pieces. The
[13] According to one embodiment of the bicycle generator, the first yoke pieces and the second yoke pieces are alternately arranged in the circumferential direction, and the first magnet facing portion and the second magnet piece are arranged in the circumferential direction. Magnet facing portions are alternately arranged in the circumferential direction.

  [14] According to one embodiment of the bicycle generator, the first yoke piece includes a U-shaped first main body part and the U-shaped one end of the first main body part from the U-shaped one end. A first magnet-facing portion that is a portion extending toward a letter-shaped opening side, and the second yoke piece includes a U-shaped second body portion and the second body portion. And a second magnet facing portion which is a portion extending from the U-shaped bottom to the side opposite to the U-shaped opening.

  [15] According to one embodiment of the bicycle generator, the first yoke piece and the second yoke piece are formed in the U-shape of the first main body portion and the second main body portion. It arrange | positions so that the direction in the said rotating shaft direction of opening may become reverse.

  [16] According to one embodiment of the bicycle generator, the coil is disposed inside the U shape of the first main body portion and inside the U shape of the second main body portion. The portions of the first main body portion and the second main body portion between the coil and the support are magnetically connected to each other.

  [17] According to one embodiment of the bicycle generator, the number of magnetic poles of the first magnet is equal to the total number of the first yoke pieces and the second yoke pieces, and the magnetic poles of the second magnets. The number is equal to the total number of the first yoke pieces and the second yoke pieces.

  [18] According to one embodiment of the bicycle generator, the first yoke piece and the second yoke piece have a surface facing the first magnet and a surface facing the second magnet. Is displaced in the circumferential direction of the support.

[19] According to one embodiment of the bicycle generator, the first yoke piece and the second yoke piece are formed by laminating plate-like magnetic bodies in the circumferential direction of the support. .
[20] According to an embodiment of the bicycle generator, the first magnet is disposed radially outward with respect to the magnet facing portion, and the second magnet is radially with respect to the magnet facing portion. Arranged inside.

[21] According to one embodiment of the bicycle generator, the first magnet is longer than the second magnet in the direction of the rotational axis.
[22] According to an embodiment of the bicycle generator, the rotating body is disposed on an outer peripheral portion provided on an outer periphery of the support and on an outer side in the rotational axis direction than the second magnet. A wall portion, wherein the first magnet is provided on an inner surface of the outer peripheral portion, and the second magnet extends from the wall portion of the rotating body toward the inside in the rotational axis direction. Is provided.

  [23] According to one embodiment of the bicycle generator, the bicycle generator is a hub dynamo.

  The bicycle generator can improve power generation efficiency.

The fragmentary sectional view of the generator for bicycles of one embodiment. The disassembled perspective view of the generator for bicycles of FIG. Sectional drawing of the generator for bicycles of FIG. Sectional drawing of the generator for bicycles along line 4-4 in FIG. Sectional drawing which shows the relationship between the 1st magnet of FIG. 4, and a 2nd magnet. The graph which shows the torque ripple of the generator for bicycles of FIG. Sectional drawing of the generator for bicycles of a modification. The fragmentary sectional view of the generator for bicycles of a modification.

A hub dynamo that is a bicycle generator will be described with reference to FIG.
The hub dynamo 10 is a so-called claw-pole generator, and includes a support 12, a rotating body 14, a coil 16, a first magnet 18, a second magnet 20, and a yoke 22.

The support 12 includes a hub axle of the front wheel, and both ends thereof are supported by the front fork F of the bicycle B so as not to rotate.
The rotating body 14 includes a hub shell, and is provided on the outer periphery of the supporting body 12 so as to be rotatable around a rotation axis C that is a central axis of the supporting body 12. Therefore, the rotating body 14 is provided so as to be rotatable with respect to the support body 12. The rotating body 14 includes a main body 24 having one end opened in the direction of the rotation axis C and a lid 26 screwed into the opening of the main body 24. The main body 24 includes a cylindrical outer peripheral portion 28, a wall 30 provided on the opposite side of the outer peripheral portion 28 from the opening in the direction of the rotation axis C, and the outer peripheral portion 28 at both axial ends of the outer peripheral portion 28. Is also provided with a flange portion 32 protruding outward in the radial direction of the rotating body 14.

  The inner periphery of the wall portion 30 and the lid portion 26 are rotatably supported by the support body 12 via bearings 34. The rotating body 14 is formed between the support 12 and the outer peripheral portion 28 in a direction along the rotation axis C from the wall 30 and on the center side of the rotation axis C (hereinafter referred to as “inner side in the axial direction of the rotation axis C”). ”) Is provided with a cylindrical support portion 30A. The flange portion 32 includes a bolt hole 32A for attaching to a spoke of a front wheel (not shown). In addition, although 30 A of support parts are formed integrally with the wall part 30, you may be fixed to the wall part 30 separately and non-rotatably. Further, the support portion 30A may be provided so as to extend from the lid portion 26 in the direction along the rotation axis C and to the center side of the rotation axis C. However, in that case, a positioning mechanism between the lid portion 26 and the main body portion 24 is required to position the relative positions of the first magnet 18 and the second magnet 20 in the circumferential direction. 24 is preferably provided on the wall 30 formed integrally with the wall 24.

  The coil 16 is disposed between the support 12 and the outer peripheral portion 28 in the radial direction of the rotating body 14. The coil 16 is wound around a bobbin 36 shown in FIG. The coil 16 is supported by the support 12 via a bobbin 36 so as not to rotate. Note that the bobbin 36 in FIG. 2 omits the tooth portions at both ends in the direction of the rotational axis C.

  The first magnet 18 shown in FIG. 1 can rotate around the rotation axis C together with the rotating body 14. The first magnet 18 is attached to the inner peripheral surface of the first holding member 38 having a cylindrical shape. As shown in FIG. 2, the first magnet 18 includes a plurality of magnetic poles 18A arranged in the circumferential direction. The number of the plurality of magnetic poles 18A is 32, for example.

  As shown in FIG. 3, the first magnet 18 is attached to the inner surface 28 </ b> A of the outer peripheral portion 28 via the first holding member 38. The first holding member 38 and the first magnet 18 are supported so as not to rotate with respect to the outer peripheral portion 28. Therefore, the first magnet 18 can rotate integrally with the rotating body 14. For example, the first holding member 38 is press-fitted into the outer peripheral portion 28. A convex portion 38 </ b> A extending in the direction of the rotation axis C is formed on the outer periphery of the first holding member 38. The convex portion 38A is fitted into a concave portion 28B formed in the inner surface 28A and extending in the direction of the rotation axis C. The convex portions 38 </ b> A and the concave portions 28 </ b> B constitute a positioning mechanism that positions the first magnet 18 in the circumferential direction with respect to the rotating body 14. The positioning mechanism may be configured by forming a concave portion in the first holding member 38 and forming a convex portion engaging with the concave portion on the inner surface 28A.

  The second magnet 20 can rotate around the rotation axis C together with the rotating body 14. The second magnet 20 is attached to the outer peripheral surface of the second holding member 40 having a cylindrical shape. As shown in FIG. 2, the second magnet 20 includes a plurality of magnetic poles 20A arranged in the circumferential direction. The number of the plurality of magnetic poles 20A is 32, for example. The number of magnetic poles 20A is the same as the number of magnetic poles 18A of the first magnet 18.

  As shown in FIG. 3, the second magnet 20 is attached to the outer surface 30 </ b> B of the support portion 30 </ b> A via the second holding member 40. The second holding member 40 and the second magnet 20 are supported so as not to rotate with respect to the support portion 30A. Therefore, the second magnet 20 can rotate integrally with the rotating body 14. The second holding member 40 is press-fitted into the support portion 30A, for example. On the outer periphery of the second holding member 40, a recess 40A extending in the direction of the rotation axis C is formed. The recess 40A is fitted into a protrusion 30C formed in the outer surface 30B and extending in the direction of the rotation axis C. The concave portion 40A and the convex portion 30C constitute a positioning mechanism for positioning in the circumferential direction with respect to the rotating body 14 of the second magnet 20. The positioning mechanism may be configured by forming a convex portion on the second holding member 40 and forming a concave portion engaging with the convex portion on the outer surface 30B. Thereby, the relative position in the circumferential direction of the first magnet and the second magnet can be easily positioned.

  As shown in FIG. 1, the first magnet 18 is longer than the second magnet 20 in the direction of the rotational axis C. The position of the end of the first magnet 18 on the wall 30 side in the direction of the rotation axis C and the position of the end of the second magnet 20 on the side of the wall 30 in the direction of the rotation axis C substantially coincide. Yes. The position of the end portion on the lid portion 26 side in the rotation axis C direction of the first magnet 18 is closer to the lid portion 26 side than the position of the end portion on the lid portion 26 side in the rotation axis C direction of the second magnet 20. Located in.

  Both the first magnet 18 and the second magnet 20 are supported so as not to rotate with respect to the rotating body 14. For this reason, the first magnet 18 and the second magnet 20 are not relatively rotatable. That is, the first magnet 18 and the second magnet 20 are supported so as to be integrally rotatable with the support body 12 together with the rotating body 14. As shown in FIG. 5, the phase around the rotation axis C of the magnetic pole 18A of the first magnet 18 and the phase around the rotation axis C of the magnetic pole 20A of the second magnet 20 are shifted by a predetermined angle D. . The predetermined angle D is preferably within a range of 15% to 30% with respect to the phase width H of one magnetic pole 18A, 20A of the first magnet 18 and the second magnet 20, and more preferably 18% to 20%. %.

  As shown in FIG. 3, the yoke 22 is disposed between the support 12 and the outer peripheral portion 28 in the radial direction of the rotating body 14. The yoke 22 is supported by the support 12 so as not to rotate. At both ends of the yoke 22 in the direction of the rotational axis C, annular positioning members 12A are arranged. The positioning member 12 </ b> A is attached to the outer periphery of the support 12. The yoke 22 is restricted from moving in the direction of the rotational axis C by the two positioning members 12A. The yoke 22 includes a main body portion 42 that faces the coil 16 in the radial direction of the support 12, and a magnet facing portion 44 that faces the magnets 18 and 20. The magnet facing portion 44 is disposed at a position that does not overlap with the coil 16 when viewed from a direction orthogonal to the direction of the rotation axis C (for example, the vertical direction in FIG. 3). The magnet facing portion 44 is located outside the coil 16 in the direction of the rotation axis C (on the wall portion 30 side).

As shown in FIG. 2, the yoke 22 includes a first yoke 46 and a second yoke 48.
The first yoke 46 is composed of a plurality of first yoke pieces 50. As shown in FIG. 3, the first yoke piece 50 includes a U-shaped first main body portion 52 and a first magnet facing portion 54. The first magnet facing portion 54 is a portion extending from one end of the first main body portion 52 to the U-shaped opening 56 side. The first yoke piece 50 is formed by laminating plate-like magnetic bodies in the circumferential direction of the support 12.

  The first main body 52 is partially disposed between the first magnet 18 and the coil 16. The first magnet facing portion 54 is disposed between the first magnet 18 and the second magnet 20. The first magnet facing portion 54 is disposed at a position that does not overlap with the coil 16 when viewed from a direction orthogonal to the rotation axis C direction (for example, the vertical direction in FIG. 3). The first magnet facing portion 54 is located outside the coil 16 in the direction of the rotation axis C (on the wall portion 30 side).

  As shown in FIG. 2, the second yoke 48 includes a plurality of second yoke pieces 58. As shown in FIG. 3, the second yoke piece 58 includes a U-shaped second body portion 60 and a second magnet facing portion 62. The second magnet facing portion 62 is a portion that extends from the bottom of the second main body portion 60 to the side opposite to the U-shaped opening 64. The second yoke piece 58 is formed by laminating plate-like magnetic bodies in the circumferential direction of the support 12.

  The second main body portion 60 is partially disposed between the first magnet 18 and the coil 16. The second magnet facing portion 62 is disposed between the first magnet 18 and the second magnet 20. The second magnet facing portion 62 is disposed at a position that does not overlap with the coil 16 when viewed from the direction orthogonal to the direction of the rotation axis C. The second magnet facing portion 62 is located outside the coil 16 in the direction of the rotation axis C (on the wall portion 30 side). That is, the second magnet facing portion 62 is disposed on the same side as the first magnet facing portion 54 with respect to the coil 16 in the direction of the rotation axis C.

  The first magnet 18 is disposed outside the support 12 in the radial direction with respect to the magnet facing portions 54 and 62. The second magnet 20 is disposed inside the support 12 in the radial direction with respect to the magnet facing portions 54 and 62.

  The number of first yoke pieces 50 and the number of second yoke pieces 58 are preferably equal. The number of first yoke pieces 50 and the number of second yoke pieces 58 are the same. The total number of first yoke pieces 50 and second yoke pieces 58 is preferably equal to the number of magnetic poles 18A of the first magnet 18. The total number of the first yoke pieces 50 and the second yoke pieces 58 is preferably equal to the number of magnetic poles 20A of the second magnet 20.

  As shown in FIG. 2, the yoke 22 is configured by alternately arranging the first yoke pieces 50 and the second yoke pieces 58 in the circumferential direction. As shown in FIG. 3, the first yoke piece 50 and the second yoke piece 58 are formed in the direction of the rotation axis C of the U-shaped opening 64 of the first main body portion 52 and the second main body portion 60. It is arranged so that the directions at are opposite. The first main body portion 52 and the second main body portion 60 constitute a main body portion 42. As shown in FIG. 4, the first magnet facing portions 54 and the second magnet facing portions 62 are alternately arranged in the circumferential direction. The first magnet facing portion 54 and the second magnet facing portion 62 constitute a magnet facing portion 44.

  The coil 16 is disposed inside the U shape of the first main body portion 52 and inside the U shape of the second main body portion 60. Of the first main body portion 52 and the second main body portion 60, portions between the coil 16 and the support 12 are magnetically connected to each other. The magnetic connection means that the first main body portion 52 and the second main body portion 60 are in direct contact with each other, and the first main body portion 52 and the second main body portion 60. This includes a state in which the air gap formed between them is sufficiently small.

The operation of the hub dynamo 10 will be described.
When the bicycle B shown in FIG. 1 is driven, the first magnet 18 rotates on the outer peripheries of the magnet facing portions 54 and 62 as the rotating body 14 rotates. Further, as the rotating body 14 rotates, the second magnet 20 rotates on the inner circumferences of the magnet facing portions 54 and 62. When the first magnet 18 and the second magnet 20 are rotated with respect to the magnet facing portions 54 and 62, the magnetic flux whose magnetic force is increased by the magnet facing portions 54 and 62 passes through the coil 16, and the coil 16 has a current. Flows. In the hub dynamo 10, since the magnetic fluxes of both the first magnet 18 and the second magnet 20 affect the magnet facing portions 54 and 62, the magnetic force passing through the coil 16 is increased as compared with the case where only one is provided. be able to. Further, as the rotating body 14 rotates, the first magnet 18 rotates with respect to the main body 42, so that the magnetic flux from the first magnet 18 passes through the coil 16 through the main body 42.

  As shown by a two-dot chain line L1 in FIG. 6, in the case of a hub dynamo in which the phase of the magnetic pole 18A of the first magnet 18 and the phase of the magnetic pole 20A of the second magnet 20 are matched, only the first magnet 18 is used. Compared with the case where only the second magnet 20 is provided (solid line L4 in FIG. 6) and the case where only the second magnet 20 is provided (dotted line L3 in FIG. 6), the torque ripple becomes large.

  In the hub dynamo 10, the phase of the magnetic pole 18A of the first magnet 18 and the phase of the magnetic pole 20A of the second magnet 20 are shifted by a predetermined angle D. For this reason, a deviation occurs in the waveform of the cogging torque caused by the first magnet 18 and the second magnet 20. For this reason, as indicated by a broken line L2 in FIG. 6, a hub dynamo in which the phase of the magnetic pole 18A of the first magnet 18 and the phase of the magnetic pole 20A of the second magnet 20 indicated by the two-dot chain line L1 in FIG. As compared with a hub dynamo including only the first magnet 18 indicated by a solid line L4, torque ripple can be reduced.

The hub dynamo 10 has the following operations and effects.
(1) The hub dynamo 10 includes a first magnet 18 and a second magnet 20 that are disposed with the magnet facing portions 54 and 62 of the yoke 22 interposed therebetween. For this reason, since the yoke 22 can receive the magnetic flux of the two magnets 18 and 20, the power generation efficiency can be improved.

  (2) The phase of the magnetic pole 18A of the first magnet 18 and the phase of the magnetic pole 20A of the second magnet 20 are shifted by a predetermined angle D. Therefore, torque ripple can be reduced as compared with a hub dynamo in which the phase of the magnetic pole 18A of the first magnet 18 and the phase of the magnetic pole 20A of the second magnet 20 are matched.

  (3) The hub dynamo 10 includes a concave portion 28B and a convex portion 38A for positioning the phase of the first magnet 18 with respect to the rotating body 14, and a convex portion 30C and a concave portion 40A for positioning the phase of the second magnet 20 with respect to the rotating body 14. And. For this reason, the phase determination when attaching the magnets 18 and 20 to the rotating body 14 can be easily performed. Further, the phase of the magnetic pole 18A of the first magnet 18 and the phase of the magnetic pole 20A of the second magnet 20 are difficult to shift.

  (4) The portions between the coil 16 and the support 12 in the first main body portion 52 and the second main body portion 60 are magnetically connected to each other. For this reason, for example, compared with the case where a big air gap is formed between the 1st main-body part 52 and the 2nd main-body part 60, since the magnetic force given to the coil 16 becomes large, electric power generation efficiency can be made high. .

  (5) The first yoke piece 50 and the second yoke piece 58 are formed by laminating plate-like magnetic bodies in the circumferential direction of the support 12. For this reason, generation | occurrence | production of the eddy current inside the yoke pieces 50 and 58 can be suppressed compared with the case where the yoke piece which shape | molded the single material using the press etc. is used. For this reason, it can suppress that power generation efficiency falls by an eddy current.

  (6) The first magnet 18 is longer than the second magnet 20. For this reason, a part of the first magnet 18 can be arranged at a position that coincides with the coil 16 in the radial direction of the support 12, and the portion where the first magnet 18 and the yoke 22 face each other can be enlarged. For this reason, compared with the case where the 1st magnet 18 is shorter than the 2nd magnet 20, electric power generation efficiency can be made high.

  (7) The lid part 26 is screwed into the main body part 24. For this reason, the phase of the cover part 26 and the main-body part 24 is easy to shift | deviate. The magnets 18 and 20 are positioned on the side of the wall 30 in the direction of the rotation axis C, and a positioning mechanism is formed on the outer peripheral portion 28 and a support 30 </ b> A extending from the wall 30. For this reason, a phase shift between the first magnet 18 and the second magnet 20 hardly occurs.

  The specific form that the bicycle generator can take is not limited to the form exemplified in the above embodiment. The bicycle generator can take various forms different from the above embodiment. The modifications of the above-described embodiment shown below are examples of various forms that the bicycle generator can take.

The phase of the magnetic pole 18A of the first magnet 18 and the phase of the magnetic pole 20A of the second magnet 20 can be substantially matched.
As shown in FIG. 7, the first yoke piece 66 and the surfaces 66D and 68D facing the first magnet 18 and the surfaces 66E and 68E facing the second magnet 20 are shifted in the circumferential direction of the 30 support. The second yoke piece 68 may be used. In this case, since the first yoke piece 66 and the second yoke piece 68 have different phase relationships between the yoke pieces 66 and 68 and the magnets 18 and 20, torque ripple can be suppressed. In this modification, it is preferable that the phase of the magnetic pole 18A of the first magnet 18 and the phase of the magnetic pole 20A of the second magnet 20 substantially coincide as shown in FIG.

  The length of the first magnet 18 in the direction of the rotation axis C can be made substantially equal to the length of the second magnet 20. In this case, as shown in FIG. 8, the outer circumferences of the first main body portion 52 and the second main body portion 60 can be changed to a shape closer to the inner surface 28 </ b> A of the rotating body 14. Thereby, since the inside of the U shape of the first main body portion 52 and the inside of the U shape of the second main body portion 60 can be increased, the number of turns of the coil 16 can be increased.

The first yoke piece 50 and the second yoke piece 58 can be formed by pressing or the like.
-The positioning mechanism with respect to the rotary body 14 of the 1st magnet 18 can also be comprised by a spline. In short, any configuration can be adopted as long as the mechanism can position the phase of the first magnet 18 with respect to the rotating body 14. Note that the positioning mechanism can be omitted, and the phase of the first magnet 18 with respect to the rotating body 14 can be determined by visual observation or the like during manufacturing.

  -The positioning mechanism with respect to the rotary body 14 of the 2nd magnet 20 can also be comprised by a spline. In short, any configuration may be employed as long as the mechanism can position the phase of the second magnet 20 with respect to the rotating body 14. In addition, a positioning mechanism is abbreviate | omitted and the phase with respect to the rotary body 14 of the 2nd magnet 20 can also be determined by visual observation etc. at the time of manufacture.

-At least one of the 1st magnet 18 and the 2nd magnet 20 can also be comprised by magnetizing the holding members 38 and 40 or a rotary body.
The number of magnetic poles 18A of the first magnet 18 and the number of magnetic poles 20A of the second magnet 20 can be made different.

The one magnet facing portions 54 and 62 of the first yoke 46 and the second yoke 48 can be omitted.
The position of the end on the wall 30 side in the direction of the rotation axis C of the first magnet 18 is different from the position of the end on the side of the wall 30 in the direction of the rotation axis C of the second magnet 20. You can also. In this case, a portion of the yoke 22 that is disposed between the first magnet 18 and the second magnet 20 in the radial direction is the magnet facing portion 44.

  The present invention can also be applied to a bicycle generator in which the rotating body 14 is disposed on the inner periphery of the cylindrical support 12. In this case, the bicycle generator includes, for example, a roller generator in which the rotating body 14 rotates by contact with a tire or a wheel rim. Further, the present invention can also be applied to a bicycle generator that is attached around a crankshaft and generates power by rotation of the crankshaft as a rotating body. Further, the present invention can also be applied to a bicycle generator that generates power by rotation of a guide pulley as a rotating body of a rear derailleur.

B bicycle 10 hub dynamo 12 support 14 rotating body 16 coil 18 first magnet 18A magnetic pole 20 second magnet 20A magnetic pole 22 yoke 28 outer peripheral portion 28A inner surface 28B concave portion (positioning mechanism)
30 Wall part 30A Support part 30B Outer surface 30C Convex part (positioning mechanism)
38A Convex part (positioning mechanism)
40A recess (positioning mechanism)
42 Main body portion 44 Magnet facing portion 46 First yoke 48 Second yoke 50 First yoke piece 52 First main body portion 54 First magnet facing portion 56 Opening 58 Second yoke piece 60 Second main body portion 62 Second magnet facing portion 64 Opening

Claims (23)

A support;
A rotating body that is provided so as to be rotatable about a rotation axis with respect to the support, and from which rotation is input from the outside;
A coil supported by the support;
A yoke supported by the support;
A first magnet and a second magnet that can rotate about the rotation axis together with the rotating body;
The yoke includes a bicycle generator including a magnet facing portion disposed between the first magnet and the second magnet.   The bicycle generator according to claim 1, wherein the first magnet and the second magnet are not relatively rotatable.   The bicycle generator according to claim 2, wherein the yoke further includes a main body part that is partially disposed between the first magnet and the coil.   The bicycle generator according to claim 2 or 3, wherein the magnet facing portion does not overlap with the coil when viewed from a direction orthogonal to the rotation axis direction.   The bicycle generator according to any one of claims 2 to 4, wherein the magnet facing portion is located on the outer side in the rotational axis direction than the coil. The first magnet includes a plurality of magnetic poles arranged in the circumferential direction,
The second magnet includes a plurality of magnetic poles arranged in the circumferential direction,
The number of magnetic poles of the first magnet and the number of magnetic poles of the second magnet are the same,
The bicycle generator according to any one of claims 2 to 5, wherein a phase of the magnetic pole of the first magnet and a phase of the magnetic pole of the second magnet are shifted by a predetermined angle.   The bicycle generator according to claim 6, wherein the predetermined angle is in a range of 15% to 30% with respect to a phase width of one magnetic pole of the first magnet and the second magnet.   The bicycle generator according to claim 4, wherein the predetermined angle is in a range of 18% to 20% with respect to a phase width of one magnetic pole of the first magnet and the second magnet. The first magnet includes a plurality of magnetic poles arranged in the circumferential direction,
The second magnet includes a plurality of magnetic poles arranged in the circumferential direction,
The number of magnetic poles of the first magnet and the number of magnetic poles of the second magnet are the same,
The bicycle generator according to any one of claims 2 to 5, wherein a phase of the magnetic pole of the first magnet and a phase of the magnetic pole of the second magnet substantially coincide with each other.   The bicycle generator according to any one of claims 2 to 9, further comprising a positioning mechanism that positions phases of the first magnet and the second magnet with respect to the rotating body. The yoke includes a first yoke and a second yoke;
The first yoke includes a first magnet facing portion,
The second yoke includes a second magnet facing portion;
The bicycle generator according to any one of claims 2 to 10, wherein the first magnet facing portion and the second magnet facing portion constitute the magnet facing portion. The first yoke is composed of a plurality of first yoke pieces,
The bicycle generator according to claim 11, wherein the second yoke is composed of a plurality of second yoke pieces. The first yoke pieces and the second yoke pieces are alternately arranged in the circumferential direction,
The bicycle generator according to claim 12, wherein the first magnet facing portions and the second magnet facing portions are alternately arranged in a circumferential direction. The first yoke piece is a U-shaped first main body portion and a portion extending from one end of the U-shaped portion of the first main body portion to the U-shaped opening side. With a magnet facing part,
The second yoke piece is a U-shaped second main body portion and a portion extending from the U-shaped bottom portion of the second main body portion to the side opposite to the U-shaped opening. The bicycle generator according to claim 12 or 13, comprising the second magnet facing portion.   The first yoke piece and the second yoke piece are arranged so that directions of the U-shaped openings of the first main body portion and the second main body portion in the direction of the rotation axis are opposite to each other. The bicycle generator according to claim 14, which is arranged. The coil is disposed inside the U-shape of the first body portion and inside the U-shape of the second body portion,
The bicycle generator according to claim 14 or 15, wherein portions of the first main body portion and the second main body portion between the coil and the support are magnetically connected to each other. The number of magnetic poles of the first magnet is equal to the total number of the first yoke piece and the second yoke piece,
The bicycle generator according to any one of claims 12 to 16, wherein the number of magnetic poles of the second magnet is equal to the total number of the first yoke pieces and the second yoke pieces.   The surface of the first yoke piece and the second yoke piece facing the first magnet and the surface facing the second magnet are shifted in the circumferential direction of the support. The bicycle generator according to any one of claims 12 to 17, wherein   The bicycle according to any one of claims 12 to 18, wherein the first yoke piece and the second yoke piece are formed by laminating plate-like magnetic bodies in a circumferential direction of the support. Generator. The first magnet is disposed radially outside the magnet facing portion,
The bicycle generator according to any one of claims 1 to 19, wherein the second magnet is disposed radially inward with respect to the magnet facing portion.   21. The bicycle generator according to claim 20, wherein the first magnet is longer than the second magnet in the rotation axis direction. The rotating body includes an outer peripheral portion provided on an outer periphery of the support, and a wall portion disposed on the outer side in the rotational axis direction than the second magnet,
The first magnet is provided on an inner surface of the outer peripheral portion,
The bicycle generator according to claim 20 or 21, wherein the second magnet is provided in a support portion that extends from the wall portion of the rotating body toward an inner side in the rotation axis direction.   The bicycle generator according to any one of claims 1 to 22, wherein the bicycle generator is a hub dynamo.