JP2016171722A - Hub dynamo gear unit, hub dynamo, and bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hub dynamo gear unit, hub dynamo, and bicycle, that are capable of generating high power even when rotational speed of a rotor is low.SOLUTION: A hub dynamo 10 comprises: a first hub cap 31 that receives force from the outside to rotate; a magnet part 20; a coil part 17 that rotates with respect to the magnet part 20; and a gear unit 32 for transmitting rotation of the first hub cap 31 to the magnet part 20. The gear unit 32 comprises a first transmission mechanism and a second transmission mechanism. Provision of at least one of the first transmission mechanism and the second transmission mechanism is sufficient. Speed of rotation of the first hub cap 31 may be increased and transmitted to the magnet part 20.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hub dynamo gear unit, a hub dynamo, and a bicycle.

  A hub dynamo is known as a generator attached to a bicycle. For example, a hub dynamo described in Patent Document 1 is a dynamo that generates three-phase AC power, and is an axle ("hub shaft" in Patent Document 1) fixed to a front fork of a bicycle and rotatable on the axle. A rotating body to be held (“Dynamo Case” in Patent Document 1), a rotor (“Rotor Unit” in Patent Document 1) fixed to the inner peripheral surface of the rotating body with an adhesive, and a stator fixed to the hub axle ("Stator unit" in Patent Document 1) and a rectifier circuit that converts an alternating current into a direct current. In the hub dynamo described in Patent Document 1, the stator has a coil, and the rotor has a magnet.

  The hub dynamo described in Patent Document 1 is attached to a bicycle such that when a wheel rotates during traveling of the bicycle, the rotating body and the rotor integrally rotate with respect to the stator about the hub shaft. Thereby, a three-phase alternating current flows through the coil included in the stator as the bicycle wheel rotates. This three-phase alternating current is converted into a direct current by a rectifier circuit and flows to a load such as a bicycle headlamp.

JP 2012-182961 A

  However, in the hub dynamo described in Patent Document 1, when the rotational speed of the wheel is low, such as when the bicycle is started or pushed by hand, the rotational speed of the rotating body and the rotor of the bicycle is low. Electric power is reduced. For this reason, in the hub dynamo described in Patent Document 1, there is a possibility that it is not possible to generate power enough to operate the load sufficiently when the bicycle is moving at a low speed.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a hub dynamo gear unit, a hub dynamo, and a hub dynamo capable of generating large electric power even when the rotational speed of the rotating body is low. It is to provide a bicycle equipped.

  In order to achieve the above object, a hub dynamo gear unit according to a first aspect of the present invention includes a plurality of gears meshing with each other, and rotates a rotating body that receives a force from the outside and rotates with respect to a stator. A transmission mechanism for transmitting to the rotating rotor.

  In order to achieve the above object, a hub dynamo according to a second aspect of the present invention includes a rotating body that rotates by receiving an external force, a stator, a rotor that rotates relative to the stator, and a plurality of meshing meshes with each other. And a transmission mechanism configured to transmit rotation of the rotating body to the rotor.

  In order to achieve the above object, a bicycle according to a third aspect of the present invention includes a hub dynamo according to the second aspect of the present invention.

  According to the present invention, the hub dynamo gear unit, the hub dynamo and the bicycle can generate large electric power even when the rotational speed of the rotating body is low.

It is sectional drawing of the hub dynamo which concerns on one Embodiment of this invention. It is an exploded front view of the hub dynamo concerning one embodiment of the present invention. 1 is an exploded perspective view of a hub dynamo according to an embodiment of the present invention. 1 is an exploded perspective view of a hub dynamo according to an embodiment of the present invention. It is a perspective view of the transmission mechanism concerning one embodiment of the present invention. It is a perspective view of the rectification | straightening part and coil part which concern on one Embodiment of this invention. It is a disassembled perspective view of the rectification | straightening part and coil part which concern on one Embodiment of this invention. It is a perspective view of the brush part which concerns on one Embodiment of this invention.

  Hereinafter, an embodiment of a hub dynamo to which a hub dynamo gear unit according to the present invention is applied will be described with reference to the drawings.

  The hub dynamo 10 is a substantially cylindrical member, and is incorporated into, for example, a hub 15 of a front wheel of a bicycle as shown in FIG. The hub 15 generally has a generally cylindrical body having openings at both ends, and ribs extending from both ends of the body. The rib is provided with a plurality of holes for fixing the spokes of the front wheel.

<Configuration>
As shown in FIGS. 1 to 4, the hub dynamo 10 surrounds the axle 18 of the front wheel of the bicycle, the substantially cylindrical magnet portion 20 fixed substantially at the center of the axle 18, and the outer peripheral surface of the magnet portion 20. Fixed to the hub 15, a cylindrical coil portion 17 provided in the inner side, a gear mechanism 30 provided near one end of the coil portion 17, a rectifying mechanism 40 provided near the other end of the coil portion 17, and the hub 15. The first hub cap 31 and the second hub cap 50 are provided. All parts of the hub dynamo 10 described below are configured so that the axle 18 can be inserted therethrough.

  The vicinity of both ends of the axle 18 is fixed to a fork (not shown) extending from a bicycle handle (not shown). For example, the vicinity of both ends of the axle 18 has a thread and is fixed to the fork by tightening a nut or the like.

  The coil portion 17 is an example of a rotor, and is a cylindrical member provided so as to surround the outer peripheral surface of the magnet portion 20. The coil portion 17 is provided to be rotatable around an axle 18 with respect to a magnet portion 20 which is an example of a stator. The magnet part 20 and the coil part 17 are accommodated in the outer case 16. The magnet unit 20 and the coil unit 17, the gear mechanism 30, and the rectifying mechanism 40 are arranged along the axle 15 and accommodated in the through hole of the hub 15. The first hub cap 31 is provided so as to close the opening of the hub 15 located in the vicinity of the gear mechanism 30. The second hub cap 50 is provided so as to close the opening of the hub 15 located in the vicinity of the rectifying mechanism 40. The first and second hub caps 31 and 50 are an example of a rotating body.

  The coil portion 17 is formed by hardening a coreless coil around which a plurality of conducting wires are wound with resin or the like. A conventional method may be adopted as a method of winding the conductive wire for forming the coreless coil. For example, the winding method disclosed in US Pat. Adopted. In the present embodiment, the coreless coil is formed by winding six conducting wires, and therefore, a total of six connecting wires 17 a extend from the coil portion 17.

  The magnet unit 20 has a plurality of columnar magnets, for example, fixed to the outer peripheral surface of a substantially cylindrical member fixed to the axle 18 with an adhesive or the like. The plurality of magnets are combined so as to form a substantially ring shape when viewed from the axle direction. In this Embodiment, the magnet part 20 has illustrated what consists of four magnets. Specifically, the magnet unit 20 has a configuration in which four magnets are magnetized along the circumferential direction of the magnet unit 20 so that N poles and S poles are alternated. A magnetic field is formed in the space where the coreless coil included in the coil unit 17 is arranged by the plurality of magnets included in the magnet unit 20. Therefore, when viewed from the axle direction, when the coil unit 17 rotates around the magnet unit 20, the interlinkage magnetic flux in each part of the coreless coil included in the coil unit 17 changes, and a back electromotive force is generated in the coreless coil. As a result of the generation of the counter electromotive force, a current flows through each of the conductive wires forming the coreless coil. In addition, the aspect of the magnet part 20 should just generate a back electromotive force in the coil part 17 with rotation of the coil part 17, and is not limited to the said aspect.

  As shown in FIG. 2, the gear mechanism 30 includes a gear unit 32, a central gear 33, and a first hub cap 31.

  As shown in FIG. 3, the first hub cap 31 includes a lid portion that closes the opening of the hub 15 and a short cylindrical portion that is fixed to the lid portion and extends in the axle direction. The cylindrical portion of the first hub cap 31 is provided with a male screw that is screwed with a female screw provided on the hub 15 on the outer peripheral surface, and an internal gear 31a is provided on the inner peripheral surface.

  A bearing 37 into which the axle 18 is inserted is fitted in the lid portion of the first hub cap 31, so that it can rotate smoothly around the axle 18.

  Further, a retaining portion 36 is fitted into the lid portion of the first hub cap 31 from the outside in order to prevent the bearing 37 from falling off and the position of the bearing 37 from shifting.

  The first hub cap 31, together with the retaining portion 36, is pressed against the gear unit 32 with a predetermined force by tightening bolts 12 c and 12 d that are screwed onto the axle 18, and the position along the axle 18 is fixed. .

  The first hub cap 31 is fixed to the hub 15 by screwing with a female screw provided in the hub 15 described above. Therefore, when the wheel rotates as the bicycle moves, the first hub cap 31 rotates in response to the force from the hub 15 that rotates with the wheel. Such a first hub cap 31 is an example of a rotating body that rotates in response to an external force.

  As shown in FIG. 5, the gear unit 32 includes a first transmission mechanism 32a, a second transmission mechanism 32b, and a substrate 35 on which these are installed. The gears of the gear unit 32 are all spur gears.

  The substrate 35 is a disk-shaped member provided with a hole through which the axle 18 is inserted at the center. The substrate 35 is fixed to the outer case 16 by screws, for example.

  The first transmission mechanism 32a includes first to fourth gear bodies 51 to 54. Each of the first to fourth gear bodies 51 to 54 is provided between the board 35 and the outer case 16 and rotates around a rotation axis parallel to the axle 18.

  The first gear body 51 has a gear that meshes with the internal gear 31 a of the first hub cap 31 and rotates around the rotation axis. The number of teeth of the first gear body 51 is smaller than the number of teeth of the internal gear 31 a of the first hub cap 31. Therefore, when the first hub cap 31 rotates, the first gear body 51 rotates at a higher rotational speed than the first hub cap 31.

  The second gear body 52 includes a small-diameter gear 52a and a large-diameter gear 52b that rotate around a common rotation axis. The small diameter gear 52 a meshes with the first gear body 51, and the number of teeth of the small diameter gear 52 a is smaller than the number of teeth of the first gear body 51. Therefore, when the first gear body 51 rotates, the second gear body 52 rotates at a higher rotational speed than the first gear body 51.

  The third gear body 53 includes a small-diameter gear 53a and a large-diameter gear 53b that rotate around a common rotating shaft. The small diameter gear 53a meshes with the large diameter gear 52b, and the number of teeth of the small diameter gear 53a is smaller than the number of teeth of the large diameter gear 52b. Therefore, when the second gear body 52 rotates, the third gear body 53 rotates at a higher rotational speed than the second gear body 52.

  The fourth gear body 54 includes a small-diameter gear 54a and a large-diameter gear 54b that rotate around a common rotation axis. The small diameter gear 54a meshes with the large diameter gear 53b, and the number of teeth of the small diameter gear 54a is smaller than the number of teeth of the large diameter gear 53b. Therefore, when the third gear body 53 rotates, the fourth gear body 54 rotates at a higher rotational speed than the third gear body 53.

  The large-diameter gear 54 b is inserted through the axle 18 and meshes with the tooth portion 32 b of the central gear 33.

  According to such a first transmission mechanism 32a, the rotational speed of the first hub cap 31 can be increased. Therefore, the central gear 33 can be rotated at a higher rotational speed than the first hub cap 31.

  The second transmission mechanism 32b has substantially the same configuration as the first transmission mechanism 32a, and is disposed symmetrically with respect to the first transmission mechanism 32a and the axle 18 when viewed from the axle direction.

  That is, in the present embodiment, the first transmission mechanism 32 a and the second transmission mechanism 32 b are arranged at 180 ° intervals, that is, equiangular intervals along the rotation direction of the coil portion 17. More specifically, for example, the first gear body 51 of the first transmission mechanism 32a is provided at a position 180 ° away from the first gear body 51 of the second transmission mechanism 32b.

  As shown in FIG. 2, the central gear 33 is a member through which the axle 18 is inserted and rotates around the axle 18. The central gear 33 is provided on the side of the magnet unit 20 via a coil spring 12e and a pair of washers 12f and 12g, and is biased toward the outer case 16 by the coil spring 12e.

  The central gear 33 is a holding gear 33a accommodated in the outer case 16, and a spur gear provided so as to protrude from the holding portion 33a toward the gear unit 32 through a hole provided in the outer case 16. And a certain tooth portion 33b.

  As shown in FIG. 2, the holding portion 33 a includes a disk-shaped portion, and this portion is fixed to one end portion of the coil portion 17.

  The tooth portion 32b meshes with the large-diameter gear 54b of the fourth gear body 54 of both transmission mechanisms 32a and 32b.

  As shown in FIG. 2, the rectifying mechanism 40 is disposed on the opposite side of the gear mechanism 30 with the magnet unit 20 interposed therebetween. Specifically, the rectifying mechanism 40 includes a brush part 41 and a rectifying part 42.

  As shown in FIG. 8, the brush portion 41 includes a pair of brushes 41 a disposed symmetrically with respect to a plane including the central axis of rotation of the coil portion 17 and a pair of brushes 41 a so as to be disposed in the outer case 16. Holding part 41b to hold.

  A conductive wire (not shown) that is electrically connected to a load such as a headlight is connected to each of the pair of brushes 41a.

  The holding portion 41b is a disk-shaped member having a hole through which the axle 18 is inserted. The holding portion 41b is fitted into the outer case 16 so as to close the opening side (the left end portion in FIG. 2) of the outer case 16. The holding portion 41b is fixed to the outer case 16 with screws or the like. The holding part 41 b holds a pair of brushes 41 a on the surface facing into the outer case 16.

  As shown in FIGS. 6 and 7, the rectifying unit 42 includes a commutator 42 a and a coil holder 42 b.

  The coil holder 42 b is a substantially disk-shaped member provided with a hole through which the axle 18 is inserted at the center, and is fixed to one end of the coil portion 17. The coil holder 42 b has a bearing 44 in the center, and the axle 18 is inserted through the bearing 44.

  Thus, one end of the coil part 17 is supported by the coil holder 42b, and the other end of the coil part 17 is supported by the central gear 33 as described above. For this reason, the coil unit 17 is configured to be rotatable around the axle 18 together with the rectifying unit 42 and the central gear 33.

  The coil holder 42b holds the commutator 42a on the surface of the coil portion 17 facing outward.

  The commutator 42a includes a plurality of electrodes 42c having a uniform arc shape when viewed from the axle direction, and the plurality of electrodes 42c are held by a coil holder 42b so as to form a cylindrical shape centered on the axle 18. Yes.

  In the present embodiment, six electrodes 42 c are provided, and each is electrically connected to six connection lines 17 a extending from the coil portion 17.

  The pair of brushes 41 a are provided at positions that are symmetrical with respect to the plane including the central axis of rotation of the coil portion 17 and abut against the plurality of first electrodes. Accordingly, any two of the six electrodes 42c are in contact with different brushes 41a. Along with the rotational position of the coil portion 17, the combination of the electrodes 42c that contact each brush 41a is switched. Thereby, the brush part 41 can output the electric current induced by the coil part 17 as a direct current.

  As shown in FIG. 1, the outer case 16 houses the coil portion 17, the rectifying mechanism 40, and the magnet portion 20. In this accommodated state, the opening of the outer case 16 is closed by the second hub cap 50. As shown in FIG. 2, the second hub cap 50 is fastened to the brush portion 41 side through the bolt 12 b and the washer 13. A bearing 37 is provided inside the second hub cap 50. The bicycle hub 15 is fixed between the first hub cap 31 and the second hub cap 50.

  As shown in FIG. 1, a connector 55 is provided outside the second hub cap 50 in the extending direction of the axle 18 (on the side opposite to the outer case 16). The connector 55 is fastened to the second hub cap 50 side through the bolt 12a. An electrical wire (not shown) extending from the brush 41a is connected to the connector 55. The connector 55 is connected to a load such as a headlight via a cable (not shown).

  So far, the configuration of the hub dynamo 10 according to the present embodiment has been described. From here, operation | movement of the hub dynamo 10 which concerns on this embodiment is demonstrated.

<Operation>
As shown in FIG. 1, the hub 15 rotates around the axle 18 as the bicycle wheel rotates. As the hub 15 rotates, both the first and second hub caps 31 and 50 rotate. The rotation of the first and second hub caps 31 and 50 is accelerated and transmitted to the central gear 33 via the first transmission mechanism 32a and the second transmission mechanism 32b. The central gear 33 rotates together with the coil unit 17 and the rectifying unit 42. At this time, the coil part 17 rotates on the outer periphery of the magnet part 20, and the coil part 17 induces a current in accordance with a change in magnetic flux generated thereby. This current is taken out as a direct current through the rectifying mechanism 40. This direct current is supplied to the load via the connector 55 and a cable (not shown).

<Effect>
According to the hub dynamo 10 which concerns on one Embodiment demonstrated so far, there exist the following effects.

  (1) The first transmission mechanism 32 a and the second transmission mechanism 32 b (gear unit 32) increase the rotational speed of the first hub cap 31 that rotates together with the hub 15 and transmits it to the coil unit 17. Thus, even when the rotation speed of the first hub cap 31 is low because the bicycle is moving at a low speed, such as when the rider starts to pedal the bicycle or when the bicycle is pushed by hand, the coil The part 17 can be rotated at high speed. Therefore, even when the rotation speed of the first hub cap 31 is low, it is possible to generate a large amount of power.

  (2) By providing the first transmission mechanism 32a and the second transmission mechanism 32b, it is possible to reduce the load applied to the transmission mechanisms 32a and 32b. Therefore, not only the durability of the hub dynamo 10 can be improved, but also the size of each transmission mechanism 32a, 32b and consequently the size of the hub dynamo 10 can be reduced. Furthermore, the design of the bicycle can be improved through downsizing of the hub dynamo 10.

  (3) The first transmission mechanism 32 a and the second transmission mechanism 32 b are arranged at intervals of 180 ° along the rotation direction of the coil portion 17. For this reason, the first transmission mechanism 32a and the second transmission mechanism 32b can rotate the central gear 33 and the coil portion 17 in a well-balanced manner. Therefore, variation in the rotation center axis of the coil portion 17 is suppressed, and stable generated power can be obtained.

  (4) The coil part 17 is formed by sealing a coreless coil with resin. Here, as in the prior art, in the configuration in which the coil is provided with the core, cogging torque is generated due to the magnetic attractive force acting between the core and the magnet. This cogging torque inhibits smooth rotation of the rotor. In this respect, in this embodiment, since a coreless coil is employed, cogging torque generated in the coil portion 17 can be suppressed. Therefore, it is possible to smoothly rotate the coil portion 17 that is a rotor. As a result, it becomes possible to drive a load such as a headlight more stably.

  (5) The coreless coil portion 17 is wound with a turtle shell winding. This tortoiseshell winding is a winding method that can increase the number of turns of the coil for a certain volume. For this reason, the coil part 17 can be comprised compactly, maintaining the electric power generation efficiency of the hub dynamo 10. FIG.

  (6) The magnet unit 20 is fixed to the axle 18, and the coil unit 17 rotates with respect to the magnet unit 20. In this way, the iron loss can be suppressed by suppressing the rotation of the magnet portion 20 and rotating the coil portion 17 by this fixing.

  (7) In this Embodiment, the coil part 17 is formed so that the outer periphery of the magnet part 20 may be enclosed, the coil part 17 is employ | adopted as a rotor, and the magnet part 20 is employ | adopted as a stator. On the other hand, even if the magnet portion 20 is employed as the rotor and the coil portion 17 is employed as the stator, the cogging torque can be suppressed as described above, and the magnet portion 20 as the rotor can be smoothly rotated. is there. However, according to the embodiment, the diameter of the coil portion 17 can be made larger than the case where the coil portion 17 is housed in the magnet portion 20 as a stator. Therefore, even if the hub dynamo 10 has the same size, it is possible to generate a large amount of power.

  (8) The hub dynamo 10 according to the present embodiment includes a brush part 41 and a rectifying part 42. Thereby, a direct current can be output from the hub dynamo 10 without providing a circuit for converting alternating current power into direct current power. Therefore, the configuration for supplying power to the load can be simplified and reduced in size.

  Hereinafter, modified examples included in the present invention will be described.

(Modification)
In the embodiment, the coreless coil of the coil portion 17 is wound by turtle shell winding (K winding), but other winding methods such as rhombus winding, honeycomb winding, etc. may be adopted as long as it is a coreless coil.

  In the embodiment, the first transmission mechanism 32a and the second transmission mechanism 32b are arranged at intervals of 180 ° along the rotation direction of the coil portion 17, but the number of transmission mechanisms can be changed as appropriate. The angular interval of the transmission mechanism can be changed according to the number of transmission mechanisms. For example, in the configuration in which the hub dynamo 10 includes three transmission mechanisms, the transmission mechanisms are arranged at 120 ° intervals along the rotation direction of the coil portion 17. That is, in order to arrange a plurality of transmission mechanisms at equal angular intervals, it is necessary to arrange the transmission mechanisms at angular intervals obtained by dividing 360 ° by the number of transmission mechanisms.

  Further, the transmission mechanisms do not have to be arranged at equiangular intervals. Even in this case, by providing a plurality of transmission mechanisms, when transmitting the rotation between the first and second hub caps 31 and 50 and the central gear 33, the load applied to each transmission mechanism can be reduced. it can.

  In the embodiment, a plurality of first transmission mechanisms 32a and second transmission mechanisms 32b are provided, but one transmission mechanism may be provided. Even in this case, the rotation of the first hub cap 31 is transmitted to the coil unit 17 with its rotational speed increased. Therefore, as described as the effect (1) above, even when the rotation speed of the first hub cap 31 is low, it is possible to generate a large amount of power.

  In the embodiment, an example in which the hub dynamo 10 is applied to a normal bicycle (a normal bicycle that travels by a rider pedaling) has been described. Such a fixed bicycle may be applied. The bicycle described in this specification and the like includes not only a normal bicycle that travels by a rider pedaling, but also a stationary bicycle. The bicycle described in this specification and the like includes not only two-wheeled bicycles but also three-wheeled bicycles and four-wheeled bicycles.

In the embodiment, the magnet unit 20 is fixed to the axle 18 and the coil unit 17 is configured to be rotatable with respect to the magnet unit 20. However, the coil unit 17 is fixed to the axle 18 and the magnet unit 20 is connected to the coil unit 17. May be configured to be rotatable. This configuration also has the effects (1) to (5).
In the embodiment, the magnet portion 20 which is an example of the stator is formed in a columnar shape, but may be formed in a prismatic shape. Moreover, although the coil part 17 which is an example of a rotor was formed in the cylindrical shape, if it is a cylinder shape, you may form in a polygonal cylinder shape.

  Various embodiments and modifications can be made to the present invention without departing from the broad spirit and scope of the present invention. The above-described embodiments are for explaining the present invention and do not limit the scope of the present invention. In other words, the scope of the present invention is shown not by the embodiments but by the claims. Various modifications within the scope of the claims and within the scope of the equivalent invention are considered to be within the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Hub dynamo 16 Outer case 17 Coil part 20 Magnet part 30 Gear mechanism 31 1st hub cap 32a 1st transmission mechanism 32b 2nd transmission mechanism 40 Rectification mechanism 41 Brush part 41a Brush 42 Rectification part 42a Commutator 50 2nd Hub cap

Claims (5)

  A hub dynamo gear unit including a transmission mechanism that includes a plurality of gears that mesh with each other, and that transmits a rotation of a rotating body that receives a force from the outside and rotates to a rotor that rotates with respect to the stator. The hub dynamo gear unit according to claim 1, wherein a plurality of the transmission mechanisms are arranged along a rotation direction of the rotor. The hub dynamo gear unit according to claim 2, wherein the plurality of transmission mechanisms are arranged at equal angular intervals along the rotation direction of the rotor. A rotating body that rotates by receiving an external force;
A stator,
A rotor that rotates relative to the stator;
A hub dynamo comprising a plurality of gears meshing with each other, and a transmission mechanism for transmitting the rotation of the rotating body to the rotor.   A bicycle comprising the hub dynamo according to claim 4.

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