Patent Application
20230034992
The present disclosure relates to a power feeding device attached to a rotary body.
As this type of power feeding circuit, there is known a power feeding circuit fixed to a wheel (see, for example, Patent Document 1).
However, in a power feeding device attached to the rotary body as in the above-described example, the power feeding device receives a centrifugal force due to rotation; therefore, the durability of the circuit board is sometimes a problem. Therefore, the present disclosure provides a technique for improving durability of a power feeding device attached to a rotary body.
The invention of claim 1 made to solve the above problem is a power feeding device including: a generator, the generator including a stator fixed to a wheel and a cylindrical rotor that rotates around a rotation axis of the wheel; an inertial member that is fixed to the cylindrical rotor and maintains a constant attitude by its own weight; a circuit board that is fixed to the stator and is mounted with a power feeding circuit to supply an output of the generator to a load; and a circuit receiving space that is provided inside the cylindrical rotor and receives a whole of the circuit board or an element that is mounted on the circuit board and protrudes from the circuit board.
A power feeding device 10A according to a first embodiment of the present disclosure will be described with reference to
As illustrated in
A front end opening of the cylinder wall 24 is closed by the lid body 22, and a space between the lid body 22 and the cylinder wall 24 is waterproof-processed. An emblem 22A is formed on an outer surface of the lid body 22. In addition, for example, the portion where the emblem 22A is formed has translucency, and the emblem 22A emits light when LEDs 82 to be described later are turned on.
A stepped surface 24D is formed at a position near the rear end of an outer surface of the cylinder wall 24, and the rear side with respect to the stepped surface 24D is a smaller diameter portion 24S. A plurality of locking pieces 25 protrudes from positions slightly displaced inward from the outer surface of a rear surface of the cylinder wall 24. The locking pieces 25 each have a structure including a locking projection 26 at a tip of a cantilever beam extending rearward. A plurality of detent projections 27 protrudes from an outer edge part of a rear surface of the housing 20. The plurality of locking pieces 25 and the plurality of detent projections 27 are dispersedly arranged in the circumferential direction of the cylinder wall 24, and a center of gravity of a whole of the housing 20 is located on the central axis of the cylinder wall 24.
A support wall 23 having an annular shape projects inward from a position near the front end inside the cylinder wall 24, and the generator 30 is fixed to the rear surface of the support wall 23. The generator 30 includes a cylindrical rotor 32 inside a stator 33 having a cylindrical shape, for example. As shown in
The generator 30 is, for example, an AC motor, in which a plurality of magnets 32J is provided on an outer surface of the cylindrical rotor 32 and in which a plurality of teeth 33T is provided on the stator 33, and an electromagnetic coil 33C is wound around each of the teeth 33T. In addition, a pair of ends of a winding wire 33M of the electromagnetic coils 33C are drawn sideward from a side surface of the stator 33, and terminal metal fittings are connected to the ends and housed in a connector 37C.
The generator 30 of the present embodiment includes a pair of output electrodes 37A and 37B to output an alternating current, but may instead include, for example, three output electrodes to output a three-phase alternating current.
As illustrated in
An inertial member 40 is fixed to a front end inside the cylindrical rotor 32. The inertial member 40 has a semicircular shape, and the inertial member 40 is fixed to the cylindrical rotor 32 such that a semicircular arc surface, which is an outer surface of the inertial member 40, is overlapped with a half of an inner peripheral surface of the cylindrical rotor 32. As a result, a center of gravity of the combined portion of the inertial member 40 and the cylindrical rotor 32 is disposed at a position shifted from the rotation axis J1 (see
The circuit board 50 is fixed to a rear end face of the stator 33. The circuit board 50 has, for example, a disk shape that just overlaps the rear end face of the stator 33. An outer edge part of the circuit board 50 is overlapped with the rear end face of the stator 33 interposing therebetween an annular spacer 59 having a diameter substantially the same as the outer diameter of the circuit board 50, and screws inserted through a plurality of through-holes 50J and 59J respectively formed in the circuit board 50 and the spacer 59 are fastened to the plurality of screw holes 33N at the rear end of the stator 33, so that the circuit board 50 is fixed to the stator 33.
As illustrated in
As illustrated in, for example,
As shown in
The housing 20 is fixed to the wheel 11 in the following manner. Specifically, the plurality of detent projections 27 of the housing 20 and the plurality of engaging recesses 14K (see
The configuration of the power feeding device 10A of the present embodiment has been described above. The power feeding device 10A is stopped and does not generate power while the vehicle 100 is stopped. However, as a diode 85A that is included in the charging circuit 85 of the electric decoration circuit 80, which is a load, is included, power is not supplied from the secondary battery 84 of the electric decoration circuit 80 to the power feeding device 10A.
When the vehicle 100 travels, the stator 33 of the generator 30 fixed to the wheel 11 of the wheel 101 rotates with respect to a road surface together with the wheel 11; however, the inertial member 40's own weight restricts rotation of the cylindrical rotor 32 of the generator 30 with respect to the road surface, and the cylindrical rotor 32 therefore rotates relatively to the stator 33. As described above, in the power feeding device 10A of the present embodiment, the rotation of the wheel 11 and an inertia of the inertial member 40 are used to rotate the cylindrical rotor 32 relatively to the stator 33 of the generator 30, thereby generating power, and the power can be supplied to the electric decoration circuit 80. In the generator 30, the elements mounted on the circuit board 50 are received in the circuit receiving space 39 inside the cylindrical rotor 32, the plurality of elements can therefore be gathered in the vicinity of the center of the rotation axis J1, and a centrifugal force applied to the circuit board 50 is accordingly reduced; therefore, durability of the power feeding device 10A is improved, and, at the same time, the generator 30 and the power feeding device 10A are made compact in the axial direction of the rotation axis J1. In addition, the electric decoration board 89 on which the electric decoration circuit 80 serving as an electric load of the power feeding device 10A is mounted is also housed in the circuit receiving space 39; therefore, the entire power feeding device 10A including the load is also made compact in this respect. In addition, in the circuit board 50 and the electric decoration board 89, the plurality of elements is disposed such that the center of gravity of the whole of the circuit board and the electric decoration board is disposed at the center of rotation. Therefore, this also improves the durability of the power feeding device 10A.
A power feeding device 10B of the present embodiment is illustrated in
(1) The generators 30 and 30V of the first and second embodiments may have the same structure as a brushed DC motor. In this case, a direct current is output from the generator 30 or 30V; therefore, the power feeding circuit 60 only has to include an electric path for relaying between the pair of output electrodes 37A and 37B of the generators 30 or 30V and the electric decoration circuit 80, or only has to include a voltage dividing circuit for adjusting a voltage to be applied to the electric decoration circuit 80.
(2) In the first and second embodiments, the load that receives power from the power feeding device 10A or 10B is the electric decoration circuit 80, but the load is not limited thereto, and may be a tire monitoring device for monitoring a state of a tire mounted on the wheel 11.
(3) In the power feeding devices 10A and 10B of the first and second embodiments, the load includes the secondary battery 84, and the power feeding devices 10A and 10B do not include a secondary battery. However, the power feeding devices 10A and 10B themselves may include a secondary battery. In that case, power can be supplied from the power feeding device 10A to the load also when the vehicle 100 is stopped.
(4) Furthermore, the inertial member 40 is not limited to the above shape, and may have any shape and any material as long as the inertial member has a center of gravity at a position shifted from the rotation axis J1, and does not have to be disposed inside the cylindrical rotor 32.
Although the present specification and the drawings disclose specific examples of the techniques included in the claims, the techniques according to the claims are not limited to these specific examples, and include various variations and modifications of the specific examples and, in addition, include a part alone taken out from the specific examples.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2021/013021 | 3/26/2021 | WO |
