Power transmission device, power reception device, and system

Abstract

This power transmission device is capable of wirelessly transmitting power to a power reception device along a power transmission direction, and includes a power transmission coil, a first shield member, and a power transmission core positioned between the power transmission coil and the first shield member in the power transmission direction. The first shield member includes: a first member constructed to overlap the power transmission core when viewed along the power transmission direction; and a second member located outside the power transmission core in a direction intersecting the power transmission direction and extending from the first member in a power transmission direction approaching the power transmission core.

Description

Power transmitting device, power receiving device and system

[0001] The present disclosure relates to a power transmitting device, a power receiving device, and a system.

[0002] Patent document 1 discloses a coil unit comprising a coil in which a conducting wire is wound in a spiral shape, a magnetic body arranged on one end side of the coil in the coil axis direction, a first metal shield arranged on the opposite side of the magnetic body facing the coil, and a second metal shield arranged to cover the periphery of the coil.

[0003] Patent No. 6555302

[0004] In the coil unit of Patent Document 1, the WPT (wireless power transmission) efficiency may decrease due to shield loss caused by an overcurrent that occurs when a magnetic field is incident on the first metal shield and the second metal shield.

[0005] An object of the present disclosure is to provide a power transmitting device, a power receiving device, and a system that can reduce leakage magnetic fields while ensuring WPT efficiency.

[0006] A power transmission device according to one aspect of the present disclosure is a power transmission device capable of wirelessly transmitting power to a power receiving device along a power transmission direction, comprising: a power transmission coil; a first shielding member that is positioned farther from the power receiving device in the power transmission direction than the power transmission coil and that positions the power transmission coil between the power receiving device in the power transmission direction; and a power transmission core that is positioned between the power transmission coil and the first shielding member in the power transmission direction, wherein the first shielding member includes: a first member configured to overlap with the power transmission core when viewed along the power transmission direction; and a second member that is positioned outside the power transmission core in a direction intersecting the power transmission direction and extends from the first member in the power transmission direction and in a direction approaching the power transmission core.

[0007] A power receiving device according to one embodiment of the present disclosure is a power receiving device capable of receiving power transmitted wirelessly from a power transmitting device along a power transmission direction, and includes: a power receiving coil; a second shield member that is positioned farther from the power transmitting device in the power transmission direction than the power receiving coil, and between the power receiving coil and the power transmitting device in the power transmission direction; and a power receiving core that is positioned between the power receiving coil and the second shield member in the power transmission direction, wherein the second shield member includes: a third member configured to overlap with the power receiving core when viewed along the power transmission direction; and a fourth member that is positioned outside the power receiving core in a direction intersecting the power transmission direction and extends from the third member in the power transmission direction and in a direction approaching the power receiving core.

[0008] a power transmitting coil; and a power receiving device capable of receiving power wirelessly transmitted from the power transmitting device along a power transmission direction, wherein the power transmitting device includes: a power transmitting coil; and a first shield member located farther from the power receiving device in the power transmission direction than the power transmitting coil, with the power transmitting coil positioned between the power receiving device in the power transmission direction; and a power transmitting core located between the power transmitting coil and the first shield member in the power transmission direction, wherein the first shield member includes: a first member configured to overlap with the power transmitting core when viewed along the power transmission direction; and a second member located outside the power transmitting core in a direction intersecting the power transmission direction and extending from the first member in the power transmission direction and in a direction approaching the power transmitting core, wherein the power receiving device includes: a power receiving coil; and a second shield member located farther from the power transmitting device in the power transmission direction than the power receiving coil, with the power receiving coil positioned between the power transmitting device in the power transmission direction. a receiving core located between the receiving coil and the second shield member in the power transmission direction, wherein the second shield member includes: a third member configured to overlap the receiving core when viewed along the power transmission direction; and a fourth member located outside the receiving core in a direction intersecting the power transmission direction and extending from the third member in the power transmission direction and in a direction approaching the receiving core.

[0009] According to the present disclosure, it is possible to realize a power transmitting device, a power receiving device, and a system that can reduce leakage magnetic fields while ensuring WPT efficiency.

[0010] 1. A block diagram showing a system according to a first embodiment of the present disclosure. 2. A perspective view showing a power transmitting device and a power receiving device of the system of FIG. 1. 3. A cross-sectional view taken along line II-II of FIG. 2. 4. A flowchart for explaining an example of power transmission processing using the power transmitting device of the system of FIG. 1. 5. A perspective view showing a first modified example of the system of FIG. 1. 6. A circuit diagram showing a second modified example of the system of FIG. 1. 7. A cross-sectional view showing a third modified example of the system of FIG. 1. 8. A cross-sectional view taken along line IX-IX of FIG. 8. 9. A perspective view showing a first modified example of the system of FIG. 8. 10. A cross-sectional view taken along line XI-XI of FIG. 10. 11. A perspective view showing a system according to a third embodiment of the present disclosure. 12. A cross-sectional view taken along line XIII-XIII of FIG. 12. 13. A cross-sectional view showing a second modified example of the system of FIG. 8. 14. A cross-sectional view showing a third modified example of the system of FIG. 8. 15. A cross-sectional view showing a fourth modified example of the system of FIG. 8. 16. A cross-sectional view showing a fifth modified example of the system of FIG. 8. 17. A cross-sectional view showing a sixth modified example of the system of FIG. 8. 18. A cross-sectional view showing a first modified example of the system of FIG. 12. 13A-13C are cross-sectional views showing a second modification of the system of Fig. 12. 13B-13C are cross-sectional views showing a third modification of the system of Fig. 12. 13C-13D are cross-sectional views showing a fourth modification of the system of Fig. 12. 13D-13E are cross-sectional views showing a fifth modification of the system of Fig. 12.

[0011] An example of the present disclosure will be described below with reference to the accompanying drawings. The following description is merely exemplary in nature and does not limit the present disclosure, its applications, or uses. The accompanying drawings are schematic drawings, and the illustrated configuration and actual products may differ in dimensional proportions, etc.

[0012] (First embodiment) As shown in Fig. 1 , a system 1 according to a first embodiment of the present disclosure includes a power transmitting device 10 and a power receiving device 20. The power transmitting device 10 is configured to be able to transmit power wirelessly to the power receiving device 20 along a power transmission direction (e.g., Z direction). The power receiving device 20 is configured to be able to receive power transmitted wirelessly from the power transmitting device 10 along the power transmission direction Z. The system 1 can employ any wireless power feeding method.

[0013] 1 , the power transmitting device 10 includes a power transmitting coil 11, a first auxiliary power transmitting coil 12, and a second auxiliary power transmitting coil 13. The power transmitting coil 11 is configured to be able to supply wireless power to a power receiving coil 21.

[0014] 1 , the power receiving device 20 includes a power receiving coil 21, a first power receiving auxiliary coil 22, and a second power receiving auxiliary coil 23. The power receiving coil 21 is configured to be able to receive wireless power supplied from the power transmitting coil 11. The wireless power received by the power receiving coil 21 is supplied to, for example, a battery (not shown) connected to the power receiving coil 21.

[0015] In this embodiment, a current is supplied to the power transmitting coil 11, the first power transmitting auxiliary coil 12, and the second power transmitting auxiliary coil 13 from a power source (e.g., a current source or a voltage source) 30. A current is supplied to the first power receiving auxiliary coil 22 and the second power receiving auxiliary coil 23 from a power source (e.g., a current source or a voltage source) 40. As shown in FIG. 2 , the power source 30 includes a power source 31 that supplies a current to the first power transmitting auxiliary coil 12, and a power source 32 that supplies a current to the second power transmitting auxiliary coil 13. The power source 40 includes a power source 41 that supplies a current to the first power receiving auxiliary coil 22, and a power source 42 that supplies a current to the second power receiving auxiliary coil 23.

[0016] 2 and 3 , the power transmission coil 11 is, for example, annular (for example, a polygonal ring including a square, or a circular ring including a perfect circle and an ellipse) and has a coil axis L1 extending along the power transmission direction Z. The power transmission coil 11 is formed of, for example, a Litz wire or a copper wire.

[0017] As an example, the first power transmitting auxiliary coil 12 has substantially the same annular shape as the power transmitting coil 11 and is positioned around the coil axis L1 of the power transmitting coil 11. The first power transmitting auxiliary coil 12 is formed of, for example, a Litz wire or a copper wire. The first power transmitting auxiliary coil 12 is positioned between the power transmitting coil 11 and the power receiving device 20 in the power transmission direction Z. In this embodiment, the first power transmitting auxiliary coil 12 is positioned substantially coaxially with the coil axis L1 of the power transmitting coil 11, but is not limited to this.

[0018] As an example, the second auxiliary power transmitting coil 13 has a ring shape larger than the power transmitting coil 11 and is positioned around the coil axis L1 of the power transmitting coil 11. The second auxiliary power transmitting coil 13 is formed of, for example, a Litz wire or a copper wire. The second auxiliary power transmitting coil 13 is positioned outside the power transmitting coil 11 in a direction intersecting the power transmitting direction Z (for example, the X direction). In this embodiment, as shown in FIG. 3 , the second auxiliary power transmitting coil 13 is positioned along a center line CL1 that passes through the center of the power transmitting coil 11 in the power transmitting direction Z and extends in a direction intersecting the power transmitting direction Z, but is not limited to this.

[0019] 2 and 3 , the power receiving coil 21 has, as an example, an annular (e.g., rectangular or circular) shape and a coil axis L2 extending along the power transmission direction Z. The power receiving coil 21 is formed of, for example, a Litz wire or a copper wire. In this embodiment, the coil axis L2 of the power receiving coil 21 is positioned approximately coaxially with the coil axis L1 of the power transmitting coil 11, but is not limited to this.

[0020] As an example, the first power-receiving auxiliary coil 22 has substantially the same annular shape as the power-receiving coil 21 and is positioned around the coil axis L2 of the power-receiving coil 21. The first power-receiving auxiliary coil 22 is formed of, for example, a Litz wire or a copper wire. The first power-receiving auxiliary coil 22 is positioned between the power-receiving coil 21 and the power transmission device 10 in the power transmission direction Z. In this embodiment, the first power-receiving auxiliary coil 22 is positioned substantially coaxially with the coil axis L2 of the power-receiving coil 21, but is not limited to this.

[0021] As an example, the second power receiving auxiliary coil 23 has a ring shape that is larger than the power receiving coil 21 and is positioned around the coil axis L2 of the power receiving coil 21. The second power receiving auxiliary coil 21 is formed of, for example, a Litz wire or a copper wire. The second power receiving auxiliary coil 23 is positioned outside the power receiving coil 21 in a direction intersecting the power transmission direction Z. In this embodiment, as shown in FIG. 3 , the second power receiving auxiliary coil 23 is positioned along a center line CL2 that passes through the center of the power receiving coil 21 in the power transmission direction Z and extends in a direction intersecting the power transmission direction Z, but is not limited to this.

[0022] In this embodiment, the power transmitting device 10 and the power receiving device 20 further include control devices 14 and 24. The control devices 14 and 24 include, for example, processors 141 and 241, storage devices 142 and 242, and communication devices 143 and 243. The processors 141 and 241 and the storage devices 142 and 242 constitute, for example, a part of a current control circuit described below. The control device 14 of the power transmitting device 10 includes an inverter, and the control device 24 of the power receiving device 20 includes a rectifier circuit.

[0023] The processors 141 and 241 include, for example, a CPU, an MPU, a GPU, a DSP, an FPGA, an ASIC, or a combination thereof. The storage devices 142 and 242 include, for example, a non-transitory computer-readable storage medium constituted by an internal or external storage medium. The internal storage medium includes a non-volatile memory, etc. The external storage medium includes a hard disk (HDD), a solid-state drive (SSD), an optical disk device, etc. The communication devices 143 and 243 include, for example, a communication circuit or a communication module for transmitting and receiving data to and from an external device such as a server, a mobile terminal device such as a smartphone or a tablet, or an external input device such as a remote controller (remote control device).

[0024] The control device 14 of the power transmitting device 10 is configured to be able to control at least one of the first current flowing through the first auxiliary power transmitting coil 12 and the second current flowing through the second auxiliary power transmitting coil 13. In this embodiment, the control device 14 is configured to be able to control both the first current and the second current, switches 33 and 34 (shown in FIG. 2 ), and the current flowing through the power transmitting coil 11. The directions of the first current and the second current are controlled by a current control circuit included in the control device 14. The first current and the second current are turned on and off by the switches 33 and 34. The current flowing through the power transmitting coil 11 may not necessarily be controlled by the control device 14, but may also be controlled by, for example, an external device.

[0025] The control device 14 is configured to be able to perform at least one of the following processes (1) and (2). Process (1): The control device 14 controls the first current so that the first current is in phase with the current flowing through the power transmitting coil 11, thereby strengthening the magnetic field in the power transmission direction Z (also referred to as a leakage magnetic field). When a detection target (e.g., a shield or a worker) is present in the strengthened magnetic field, a specific parameter changes compared to when the detection target is not present. From this change in the parameter, the control device 14 detects whether the detection target is present in the power transmission direction Z (in other words, whether the detection target is present in a range or area located in the power transmission direction Z relative to the power transmitting device 10). When the presence of the detection target is detected, the control device 14 identifies the range in which the detection target is present and controls the first current so that the first current is in opposite phase to the current flowing through the power transmitting coil 11, thereby suppressing the magnetic field in the power transmission direction Z of the power transmitting device 10. Process (2) The control device 14 controls the second current so that the second current is in phase with the current flowing through the power transmission coil 11, thereby strengthening the magnetic field in a direction intersecting the power transmission direction Z. When a detection target is present in the strengthened magnetic field, a specific parameter changes compared to when the detection target is not present. From this change in the parameter, the control device 14 detects whether the detection target is present in a direction intersecting the power transmission direction Z (in other words, whether the detection target is present in a range or area located in a direction intersecting the power transmission direction Z relative to the power transmission device 10). When the presence of the detection target is detected, the control device 14 identifies the range in which the detection target is present and controls the second current so that the second current is in opposite phase to the current flowing through the power transmission coil 11, thereby suppressing the magnetic field of the power transmission device 10 in a direction intersecting the power transmission direction Z.

[0026] Simultaneous control of the first current and the second current enables detection of the presence of a detection target and suppression of a magnetic field in a three-dimensional range around the power transmitting device 10. The range of detection targets that can be detected by each auxiliary coil and the range of magnetic fields that can be suppressed can be set by changing the positions of the first auxiliary power transmitting coil 12 and the second auxiliary power transmitting coil 13 relative to the power transmitting coil 11. For example, when the second auxiliary power transmitting coil 13 is positioned between the power transmitting coil 11 and the first auxiliary power transmitting coil 12 in the power transmission direction Z, the control device 14 can detect whether a detection target is present in the lower right and lower left directions of the power transmitting device 10 in FIG. 3 and can suppress the magnetic fields in the lower right and lower left directions of the power transmitting device 10 in FIG. 3.

[0027] The control device 24 of the power receiving device 20 is configured to be able to control at least one of the third current flowing through the first auxiliary power receiving coil 22 and the fourth current flowing through the second auxiliary power receiving coil 23. In this embodiment, the control device 24 is configured to be able to control both the third current and the fourth current, and switches 43 and 44 (shown in FIG. 2 ). The directions of the third current and the fourth current are controlled by a current control circuit included in the control device 24. The third current and the fourth current are turned on and off by the switches 43 and 44.

[0028] The control device 24 is configured to perform at least one of the following processes (3) and (4). Process (3): The control device 24 controls the third current so that the third current is in phase with the current flowing through the power receiving coil 21, thereby strengthening the magnetic field in the power transmission direction Z. When a detection target is present in the strengthened magnetic field, a specific parameter changes compared to when the detection target is not present. From this change in the parameter, the control device 24 detects whether the detection target is present in the power transmission direction Z (in other words, whether the detection target is present in a range or area located in the power transmission direction Z relative to the power receiving device 20). When the presence of the detection target is detected, the control device 24 identifies the range in which the detection target is present and controls the third current so that the third current is in phase with the current flowing through the power receiving coil 21, thereby suppressing the magnetic field of the power receiving device 20 in the power transmission direction Z. Process (4): The control device 24 controls the fourth current so that the fourth current is in phase with the current flowing through the power receiving coil 21, thereby strengthening the magnetic field in a direction intersecting the power transmission direction Z. When a detection target is present in the strengthened magnetic field, a specific parameter changes compared to when the detection target is not present. Based on this change in parameter, the control device 24 detects whether the detection target is present in a direction intersecting the power transmission direction Z (in other words, whether the detection target is present in a range or area located in a direction intersecting the power transmission direction Z relative to the power receiving device 20). When the presence of the detection target is detected, the control device 24 identifies the range in which the detection target is present and controls the fourth current so that the fourth current is in opposite phase to the current flowing through the power receiving coil 21, thereby suppressing the magnetic field of the power receiving device 20 in a direction intersecting the power transmission direction Z.

[0029] Simultaneous control of the third current and the fourth current enables detection of the presence of a detection target and suppression of a magnetic field in a three-dimensional range around the power receiving device 20. Changing the positions of the first power receiving auxiliary coil 22 and the second power receiving auxiliary coil 23 relative to the power receiving coil 21 enables setting the range of detection targets that can be detected by each auxiliary coil and the range of magnetic fields that can be suppressed. For example, when the second power receiving auxiliary coil 23 is positioned between the power receiving coil 21 and the first power receiving auxiliary coil 22 in the power transmission direction Z, the control device 34 can detect whether a detection target is present in the upper right and upper left directions of the power receiving device 20 in FIG. 3 and can suppress the magnetic fields in the upper right and upper left directions of the power receiving device 20 in FIG. 3.

[0030] In processes (1) to (4), "the first to fourth currents are in opposite phase to the current flowing in the power transmitting coil 11 or the power receiving coil 21" means, for example, that when viewed along the power transmission direction Z, the direction in which the Nth current flows is opposite to the direction in which the current flows in the power transmitting coil 11 or the power receiving coil 21. "The first to fourth currents are in phase with the current flowing in the power transmitting coil 11 or the power receiving coil 21" means, for example, that when viewed along the power transmission direction Z, the direction in which the Nth current flows is the same as the direction in which the current flows in the power transmitting coil 11 or the power receiving coil 21.

[0031] In processes (1) to (4), the area where the magnetic field is strengthened is set based on the relative positions of the power transmitting coil 11 (or power receiving coil 21) and each auxiliary coil, and the relative amplitudes of the currents supplied to each coil.

[0032] In processes (1) to (4), the specific parameters include, for example, the degree of coupling between the power transmitting coil 11 (or the power receiving coil 21) and each auxiliary coil, the value of the current flowing through each auxiliary coil, or the input impedance of each auxiliary coil. An example of a method for acquiring the input impedance of each auxiliary coil is shown below. Assume that the power transmitting device 10 or the power receiving device 20 is configured to pass a constant-amplitude current through each auxiliary coil using a constant-current source such as an inverter (DC to AC) (see FIG. 2). In this case, the input impedance of each auxiliary coil is acquired from the voltage measured using a voltmeter connected in parallel to each auxiliary coil as viewed from the current source and the current flowing through each auxiliary coil. Assume that the power transmitting device 10 or the power receiving device 20 is configured to apply a constant-amplitude voltage to each auxiliary coil using a constant-voltage source (see FIGS. 5 and 6). In this case, the input impedance of each auxiliary coil is acquired from the change in current measured using an ammeter connected in series to each auxiliary coil and the voltage source and the voltage applied to each auxiliary coil.

[0033] An example of the power transmission process of the power transmission device 10 will be described with reference to Fig. 4. In the power transmission process of Fig. 4, the control device 14 is configured to be able to perform process (1) and process (2). The power transmission process shown in Fig. 4 is performed, for example, by the processor 141 executing a predetermined program stored in the storage device 142.

[0034] As shown in Figure 4, when the power transmission process is started, the control device 14 controls the first current and the second current to pass a current in phase with the current flowing through the power transmission coil 11 through the first power transmission auxiliary coil 12 and the second power transmission auxiliary coil 13 (step S1), thereby strengthening the magnetic field in the power transmission direction Z and in a direction intersecting the power transmission direction Z (step S2).

[0035] When the magnetic field is strengthened, the control device 14 determines whether or not a detection target exists in the range located in the power transmission direction Z of the power transmitting device 10 and in a direction intersecting the power transmission direction Z (step S3).

[0036] If it is determined that a detection target is present, the control device 14 identifies the range in which the detection target is present (step S4), and selects an auxiliary power transmission coil capable of suppressing the magnetic field in the identified range (step S5). After the auxiliary power transmission coil is selected, the control device 14 causes a current of opposite phase to the current flowing through the power transmission coil 11 to flow through the selected auxiliary coil (step S6), thereby suppressing the magnetic field in the identified range (step S7).

[0037] If it is determined in step S3 that a detection target is not present, or if the magnetic field in the range identified in step S7 is suppressed, the control device 14 determines whether to terminate the power transmission process (step S8). The control device 14 determines to terminate the power transmission process, for example, when the supply of current from the power source 30 to the power transmission coil 11 is stopped, or when a command to terminate the power transmission process is received via the communication device 143 or the like. If it is not determined to terminate the power transmission process, the process returns to step S3, and it is determined whether a detection target is present in the range located in the power transmission direction Z of the power transmission device 10 and in a direction intersecting the power transmission direction Z.

[0038] The power transmission process shown in FIG. 4 can also be applied to the power reception process of the power receiving device 20 that includes the control device 24 that can perform the process (3) and the process (4).

[0039] The power transmission device 10 of the first embodiment can achieve the following effects.

[0040] The power transmitting device 10 is capable of wirelessly transmitting power to the power receiving device 20 along the power transmission direction Z, and includes a power transmitting coil 11, a first auxiliary power transmitting coil 12, and a second auxiliary power transmitting coil 13. The first auxiliary power transmitting coil 12 is configured so that the power transmitting coil 11 is located between the first auxiliary power transmitting coil 12 and the power receiving device 20 in the power transmission direction Z. The second auxiliary power transmitting coil 13 is located outside the power transmitting coil 11 in a direction intersecting the power transmission direction Z. With this configuration, it is possible to realize a power transmitting device 10 that can cancel magnetic flux in accordance with the surrounding environment.

[0041] The power transmitting device 10 includes a control device 14 capable of controlling a first current flowing through the first auxiliary power transmitting coil 12. The control device 14 is configured to control the first current so that the first current is in phase with the current flowing through the power transmitting coil 11, thereby detecting whether or not a detection target is present in the power transmitting direction Z. This configuration more reliably realizes the power transmitting device 10 capable of canceling magnetic flux in accordance with the surrounding environment.

[0042] When the control device 14 detects the presence of a detection target, the control device 14 controls the first current so that the first current is in opposite phase to the current flowing through the power transmitting coil 11, thereby suppressing the magnetic field in the power transmitting direction Z. This configuration more reliably realizes the power transmitting device 10 that can cancel magnetic flux in accordance with the surrounding environment.

[0043] The power transmitting device 10 includes a control device 14 capable of controlling the second current flowing through the second auxiliary power transmitting coil 13. The control device 14 is configured to control the second current so that the second current is in phase with the current flowing through the power transmitting coil 11, thereby detecting whether or not a detection target is present in a direction intersecting the power transmitting direction Z. This configuration more reliably realizes the power transmitting device 10 capable of canceling magnetic flux in accordance with the surrounding environment.

[0044] When the control device 14 detects the presence of a detection target, the control device 14 controls the second current so that the second current is in opposite phase to the current flowing through the power transmission coil 11, thereby suppressing the magnetic field in a direction intersecting the power transmission direction Z. This configuration more reliably realizes the power transmission device 10 that can cancel magnetic flux in accordance with the surrounding environment.

[0045] The power receiving device 20 of the first embodiment can achieve the following effects.

[0046] The power receiving device 20 is capable of receiving power wirelessly transmitted from the power transmitting device 10 along the power transmission direction Z, and includes a power receiving coil 21, a first power receiving auxiliary coil 22, and a second power receiving auxiliary coil 23. The first power receiving auxiliary coil 22 is configured so that the power receiving coil 20 is located between it and the power transmitting device 10 in the power transmission direction Z. The second power receiving auxiliary coil 23 is located outside the power receiving coil 21 in a direction intersecting the power transmission direction Z. This configuration makes it possible to realize a power receiving device 20 that can cancel magnetic flux in accordance with the surrounding environment.

[0047] The power receiving device 20 includes a control device 24 capable of controlling the third current flowing through the first auxiliary power receiving coil 22. The control device 24 is configured to control the third current so that the third current is in phase with the current flowing through the power receiving coil 21, thereby detecting whether or not a detection target is present in the power transmission direction Z. This configuration more reliably realizes the power receiving device 20 that can cancel magnetic flux in accordance with the surrounding environment.

[0048] When the control device 24 detects the presence of a detection target, the control device 24 controls the third current so that the third current is in opposite phase to the current flowing through the power receiving coil 21, thereby suppressing the magnetic field in the power transmission direction Z. This configuration more reliably realizes the power receiving device 20 that can cancel magnetic flux in accordance with the surrounding environment.

[0049] The power receiving device 20 includes a control device 24 capable of controlling a fourth current flowing through the second auxiliary power receiving coil 23. The control device 24 controls the fourth current so that the fourth current is in phase with the current flowing through the power receiving coil 21, and is configured to detect whether or not a detection target is present in a direction intersecting the power transmission direction Z. This configuration more reliably realizes the power receiving device 20 that can cancel magnetic flux in accordance with the surrounding environment.

[0050] When the control device 24 detects the presence of a detection target, the control device 24 controls the fourth current so that the fourth current is in opposite phase to the current flowing through the power receiving coil 21, thereby suppressing the magnetic field in a direction intersecting the power transmission direction Z. This configuration more reliably realizes the power receiving device 20 that can cancel magnetic flux in accordance with the surrounding environment.

[0051] The system 1 of the first embodiment can achieve the following effects.

[0052] The system 1 includes a power transmitting device 10 and a power receiving device 20 capable of receiving power wirelessly transmitted from the power transmitting device 10 along a power transmission direction Z. The power transmitting device 10 includes a power transmitting coil 11, a first power transmitting auxiliary coil 12, and a second power transmitting auxiliary coil 13. The first power transmitting auxiliary coil 12 is configured so that the power transmitting coil 11 is located between the power transmitting device 10 and the power receiving device 20 in the power transmission direction Z. The second power transmitting auxiliary coil 13 is located outside the power transmitting coil 11 in a direction intersecting the power transmission direction Z. The power receiving device 20 includes a power receiving coil 21, a first power receiving auxiliary coil 22, and a second power receiving auxiliary coil 23. The first power receiving auxiliary coil 22 is configured so that the power receiving coil 20 is located between the power transmitting device 10 and the first power receiving auxiliary coil 22 in the power transmission direction Z. The second power receiving auxiliary coil 23 is located outside the power receiving coil 21 in a direction intersecting the power transmission direction Z. With this configuration, it is possible to realize a system 1 that can cancel magnetic flux in accordance with the surrounding environment.

[0053] The system 1, the power transmitting device 10, and the power receiving device 20 of the first embodiment can be configured as follows.

[0054] The first, second, third, and fourth currents are not limited to being controlled by a current control circuit. For example, as shown in FIG. 5 , a circuit can be configured by connecting variable capacitors 35, 36, 45, and 46 in series with each auxiliary coil, and the directions of the first, second, third, and fourth currents can be controlled by changing the capacitances of the variable capacitors 35, 36, 45, and 46. By setting the capacitances of the variable capacitors 35, 36, 45, and 46 to values ​​smaller than those in the resonant state, the magnetic fields generated by each auxiliary coil and the magnetic fields generated by the power transmitting coil 11 or the power receiving coil 21 are in phase, thereby strengthening the magnetic fields. On the other hand, by setting the capacitances of the variable capacitors 35, 36, 45, and 46 to values ​​larger than those in the resonant state, the magnetic fields generated by each auxiliary coil and the magnetic fields generated by the power transmitting coil 11 or the power receiving coil 21 are out of phase, thereby suppressing the magnetic fields.

[0055] In the system 1 of Fig. 5, the circuit including the variable capacitors 35, 36, 45, and 46 can be replaced with the circuit shown in Fig. 6. The circuit shown in Fig. 6 includes two capacitors 51 and 52 and two switches 61 and 62, and the capacitors 51 and 52 connected to the respective auxiliary coils can be switched by controlling the two switches 61 and 62.

[0056] As shown in FIG. 7 , the power transmitting device 10 can include a third power transmitting auxiliary coil 15 and a fourth power transmitting auxiliary coil 16 in addition to the first power transmitting auxiliary coil 12 and the second power transmitting auxiliary coil 13. The third power transmitting auxiliary coil 15 is configured so that the first power transmitting auxiliary coil 12 is located between the third power transmitting auxiliary coil 15 and the power transmitting coil 11 in the power transmitting direction Z. The fourth power transmitting auxiliary coil 16 is located outside the second power transmitting auxiliary coil 13 in a direction intersecting the power transmitting direction Z. This configuration widens the range of the magnetic field that can be strengthened and suppressed. The power transmitting device 10 may include only one of the third power transmitting auxiliary coil 15 and the fourth power transmitting auxiliary coil 16. The power transmitting device 10 may include a power transmitting auxiliary coil in which the third power transmitting auxiliary coil 15 is located between the third power transmitting auxiliary coil 15 and the first power transmitting auxiliary coil 12 in the power transmitting direction Z. The power transmitting device 10 may include a power transmitting auxiliary coil located outside the fourth power transmitting auxiliary coil 16 in a direction intersecting the power transmitting direction Z. The currents flowing through all the auxiliary power transmission coils are controlled by, for example, the control device 14 .

[0057] As shown in FIG. 7 , the power receiving device 20, like the power transmitting device 10, can also include a third power receiving auxiliary coil 25 and a fourth power receiving auxiliary coil 26. The third power receiving auxiliary coil 25 is configured so that the first power receiving auxiliary coil 22 is located between the third power receiving auxiliary coil 25 and the power receiving coil 21 in the power transmission direction Z. The fourth power receiving auxiliary coil 26 is located outside the second power receiving auxiliary coil 23 in a direction intersecting the power transmission direction Z. This configuration widens the range of the magnetic field that can be strengthened and suppressed. The power receiving device 20 may include only one of the third power receiving auxiliary coil 25 and the fourth power receiving auxiliary coil 26. The power receiving device 20 may include a power receiving auxiliary coil in which the third power receiving auxiliary coil 25 is located between the third power receiving auxiliary coil 25 and the first power receiving auxiliary coil 22 in the power transmission direction Z. The power receiving device 20 may also include a power receiving auxiliary coil located outside the fourth power receiving auxiliary coil 26 in a direction intersecting the power transmission direction Z. The currents flowing through all of the power receiving auxiliary coils are controlled by, for example, the control device 14.

[0058] The power transmitting device 10 and the power receiving device 20 are not limited to being configured as a single device including the control devices 14 and 24. For example, the control devices 14 and 24 may be distributed across any number of networked computers, or may be provided in each of any number of networked computers. In other words, the control devices 14 and 24 may or may not constitute a part of the power transmitting device 10 and the power receiving device 20.

[0059] The power sources 30 and 40 may or may not constitute a part of the power transmitting device 10 and the power receiving device 20 .

[0060] The power transmitting device 10 may include a power transmitting core 18 located between the power transmitting coil 11 and the first power transmitting auxiliary coil 12 in the power transmission direction Z (see FIGS. 8 and 9). Similarly, the power receiving device 20 may include a power receiving core 28 located between the power receiving coil 21 and the first power receiving auxiliary coil 22 in the power transmission direction Z (see FIGS. 8 to 11).

[0061] A first embodiment of the present disclosure is described below with reference numerals.

[0062] The power transmission device 10 of the first aspect of the first embodiment is a power transmission device 10 capable of transmitting power wirelessly transmitted along a power transmission direction to a power receiving device 20, and includes a power transmission coil 11, a first power transmission auxiliary coil 12 positioned between the power transmission coil 11 and the power receiving device 20 in the power transmission direction, and a second power transmission auxiliary coil 13 positioned outside the power transmission coil 11 in a direction intersecting the power transmission direction.

[0063] The power transmission device 10 of the second aspect of the first embodiment is the power transmission device 10 of the first aspect, further including a third auxiliary power transmission coil 15 between which the first auxiliary power transmission coil 12 is located in the power transmission direction and the power transmission coil 11.

[0064] The power transmission device 10 of a third aspect of the first embodiment is the power transmission device 10 of the first or second aspect, further comprising a fourth auxiliary power transmission coil 16 positioned outside the second auxiliary power transmission coil 13 in a direction intersecting the power transmission direction.

[0065] The power transmission device 10 of a fourth aspect of the first embodiment is the power transmission device 10 of any one of the first to third aspects, and is provided with a control device 14 capable of controlling a first current flowing through the first power transmission auxiliary coil 12, and the control device 14 is configured to control the first current so that the first current is in phase with the current flowing through the power transmission coil 11, thereby being able to detect whether or not a detection object is present in the power transmission direction.

[0066] The fifth aspect of the first embodiment of the power transmission device 10 is the power transmission device 10 of the fourth aspect, wherein the control device 14 is configured, when detecting the presence of the detection object, to control the first current so that the first current is in opposite phase to the current flowing in the power transmission coil 11, thereby suppressing the magnetic field in the power transmission direction.

[0067] The power transmission device 10 of a sixth aspect of the first embodiment is the power transmission device 10 of any one of the first to fifth aspects, and is provided with a control device 14 capable of controlling the second current flowing through the second power transmission auxiliary coil 13, and the control device 14 is configured to control the second current so that the second current is in phase with the current flowing through the power transmission coil 11, and to be able to detect whether or not a detection object is present in a direction intersecting the power transmission direction.

[0068] The seventh aspect of the first embodiment is the power transmission device 10 of the sixth aspect, wherein the control device 14 is configured, when detecting the presence of the detection object, to control the second current so that the second current is in opposite phase to the current flowing in the power transmission coil 11, thereby suppressing the magnetic field in a direction intersecting the power transmission direction.

[0069] The power receiving device 20 of the eighth aspect of the first embodiment is a power receiving device 20 capable of receiving power wirelessly transmitted from the power transmitting device 10 along the power transmission direction, and comprises a power receiving coil 21, a first power receiving auxiliary coil 22 between the power receiving coil 21 and the power transmitting device 10 in the power transmission direction, and a second power receiving auxiliary coil 23 located outside the power receiving coil 21 in a direction intersecting the power transmission direction.

[0070] The power receiving device 20 of a ninth aspect of the first embodiment is the power receiving device 20 of the eighth aspect, further comprising a third auxiliary power receiving coil 25, with the first auxiliary power receiving coil 22 located between it and the power receiving coil 21 in the power transmission direction.

[0071] The power receiving device 20 of a tenth aspect of the first embodiment is the power receiving device 20 of the eighth or ninth aspect, further comprising a fourth power receiving auxiliary coil 26 positioned outside the second power receiving auxiliary coil 23 in a direction intersecting the power transmission direction.

[0072] The power receiving device 20 of an eleventh aspect of the first embodiment is the power receiving device 20 of any one of the eighth to tenth aspects, and is provided with a control device 24 capable of controlling a third current flowing through the first power receiving auxiliary coil 22, and the control device 24 is configured to control the third current so that the third current is in phase with the current flowing through the power receiving coil 21, thereby being able to detect whether or not a detection object is present in the power transmission direction.

[0073] The power receiving device 20 of the 12th aspect of the first embodiment is the power receiving device 20 of the 11th aspect, wherein the control device 24 is configured to, when detecting the presence of the detection object, control the third current so that the third current is in opposite phase to the current flowing in the power receiving coil 21, thereby suppressing the magnetic field in the power transmission direction.

[0074] The power receiving device 20 of a thirteenth aspect of the first embodiment is a power receiving device 20 of any one of the eighth to twelfth aspects, further comprising a control device 24 capable of controlling a fourth current flowing through the second power receiving auxiliary coil 23, and the control device 24 is configured to control the fourth current so that the fourth current is in phase with the current flowing through the power receiving coil 21, thereby being able to detect whether or not a detection object exists in a direction intersecting the power transmission direction.

[0075] The power receiving device 20 of the 14th aspect of the first embodiment is the power receiving device 20 of the 13th aspect, wherein the control device 24 is configured, when detecting the presence of the detection object, to control the fourth current so that the fourth current is in opposite phase to the current flowing in the power receiving coil 21, thereby suppressing the magnetic field in a direction intersecting the power transmission direction.

[0076] A system 1 of a fifteenth aspect of the first embodiment comprises a power transmission device 10 and a power receiving device 20 capable of receiving power transmitted wirelessly from the power transmission device 10 along the power transmission direction, wherein the power transmission device 10 includes a power transmission coil 11, a first power transmission auxiliary coil 12 between the power transmission coil 11 and the power receiving device 20 in the power transmission direction, and a second power transmission auxiliary coil 13 located outside the power transmission coil 11 in a direction intersecting the power transmission direction, and the power receiving device 20 includes a power receiving coil 21, a first power receiving auxiliary coil 22 between the power receiving coil 21 and the power transmission device 10 in the power transmission direction, and a second power receiving auxiliary coil 23 located outside the power receiving coil 21 in the direction intersecting the power transmission direction.

[0077] 8 and 9 , a power transmitting device 10 of a system 1 of a second embodiment includes a power transmitting coil 11, a first auxiliary power transmitting coil 12 (an example of an auxiliary power transmitting coil), and a first shield member 17. In this embodiment, the power transmitting device 10 further includes a power transmitting core 18. A power receiving device 20 of the system 1 of the second embodiment includes a power receiving coil 21, a first auxiliary power receiving coil 22 (an example of an auxiliary power receiving coil), and a second shield member 27. In this embodiment, the power receiving device 20 further includes a power receiving core 28.

[0078] 9 , the first shield member 17 of the power transmission device 10 is positioned farther from the power receiving device 20 than the power transmission coil 11 is positioned in the power transmission direction Z, and is configured so that the power transmission coil 11 is positioned between the first shield member 17 and the power receiving device 20 in the power transmission direction Z. The first auxiliary power transmission coil 12 is positioned between the power transmission coil 11 and the first shield member 17 in the power transmission direction Z.

[0079] In this embodiment, the first shield member 17 includes a first member 171 having a substantially rectangular plate shape and a first magnetic member 173. The first member 171 is formed, for example, from a non-magnetic conductor (e.g., aluminum or copper). The first magnetic member 173 is formed, for example, from ferrite. The first magnetic member 173 is provided on a portion of the first member 171 that faces the power transmitting coil 11 in the power transmission direction Z and on both ends of the first member 171 in a direction intersecting the power transmission direction Z (e.g., the X direction), but is not limited to this. The first magnetic member 173 may be provided on at least a portion of the portion of the first member 171 that faces the power transmitting coil 11 in the power transmission direction Z.

[0080] As shown in FIG. 9 , the power transmission core 18 is located between the power transmission coil 11 and the first auxiliary power transmission coil 12 in the power transmission direction Z. The power transmission core 18 is formed of a magnetic material such as ferrite. As shown in FIGS. 8 and 9 , the power transmission core 18 includes a first main body 181 configured to overlap the power transmission coil 11 when viewed along the power transmission direction Z. In this embodiment, the first main body 181 has a substantially rectangular plate shape and is formed of a magnetic material such as ferrite. The first main body 181 is configured so that the power transmission coil 11 is located inside the outline of the power transmission core 18 when viewed along the power transmission direction Z. As an example, the first main body 181 has substantially the same shape and size as the first shield member 17.

[0081] In the power transmission direction Z, gaps are formed between the power transmission coil 11 and the power transmission core 18, between the power transmission core 18 and the first auxiliary power transmission coil 12, and between the first auxiliary power transmission coil 12 and the first shield member 17. The size of the gaps can be changed, for example, in units of mm (millimeters). Increasing the gaps makes it easier to achieve the effect of suppressing shielding loss. The gaps may be filled with a material such as resin.

[0082] 9 , the second shield member 27 of the power receiving device 20 is positioned farther from the power transmitting device 10 than the power receiving coil 21 is positioned in the power transmission direction Z, and is configured so that the power receiving coil 21 is positioned between the power receiving coil 21 and the power transmitting device 10 in the power transmission direction Z. The first power receiving auxiliary coil 22 is positioned between the power receiving coil 21 and the second shield member 27 in the power transmission direction Z.

[0083] In this embodiment, the second shield member 27 includes a third member 271 having a substantially rectangular plate shape and a second magnetic member 273. The third member 271 is formed, for example, from a non-magnetic conductor (e.g., aluminum or copper). The second magnetic member 273 is provided on a portion of the third member 271 that faces the power receiving coil 21 in the power transmission direction Z and on both ends of the third member 271 in a direction intersecting the power transmission direction Z (e.g., the X direction), but is not limited to this. The second magnetic member 273 may be provided on at least a portion of the portion of the third member 271 that faces the power receiving coil 21 in the power transmission direction Z.

[0084] As shown in FIG. 9 , the power receiving core 28 is located between the power receiving coil 21 and the first power receiving auxiliary coil 22 in the power transmission direction Z. The power receiving core 28 is formed of a magnetic material such as ferrite. As shown in FIGS. 8 and 9 , the power receiving core 28 includes a second main body 281 configured to overlap the power receiving coil 21 when viewed along the power transmission direction Z. In this embodiment, the second main body 281 has a substantially rectangular plate shape and is formed of a magnetic material such as ferrite. The second main body 281 is configured so that the power receiving coil 21 is located inside the outline of the power receiving core 28 when viewed along the power transmission direction Z. As an example, the second main body 281 has substantially the same shape and size as the second shield member 27.

[0085] In the power transmission direction Z, gaps are formed between the power receiving coil 21 and the power receiving core 28, between the power receiving core 28 and the first auxiliary power receiving coil 22, and between the first auxiliary power receiving coil 22 and the second shield member 27. The size of the gaps can be changed, for example, in millimeters (mm). Increasing the gaps makes it easier to achieve the effect of suppressing shield loss. The gaps may be filled with a material such as resin.

[0086] The power transmission device 10 of the second embodiment can achieve the following effects.

[0087] The power transmitting device 10 is capable of wirelessly transmitting power to the power receiving device 20 along the power transmission direction Z and includes a power transmitting coil 11, a first shield member 17, and a first power transmitting auxiliary coil 12. The first shield member 17 is positioned farther from the power receiving device 20 in the power transmission direction Z than the power transmitting coil 11, and is configured so that the power transmitting coil 11 is located between the first shield member 17 and the power receiving device 20 in the power transmission direction Z. The first power transmitting auxiliary coil 12 is positioned between the power transmitting coil 11 and the first shield member 17 in the power transmission direction Z. With this configuration, for example, the current flowing through the first power transmitting auxiliary coil 12 is opposite in phase to the current flowing through the power transmitting coil 11, thereby suppressing a magnetic field incident on the first shield member 17. As a result, the power transmitting device 10 can be realized, which is capable of suppressing shielding loss caused by eddy currents that are generated when a magnetic field is incident on the first shield member 17.

[0088] The first shield member 17 includes a first magnetic member 173 provided in a portion facing the power transmission coil 11 in the power transmission direction Z. With this configuration, it is possible to realize the power transmission device 10 that can more reliably suppress shield loss.

[0089] The power receiving device 20 of the second embodiment can achieve the following effects.

[0090] The power receiving device 20 is capable of receiving power wirelessly transmitted from the power transmitting device 10 along the power transmission direction Z, and includes a power receiving coil 21, a second shield member 27, and a first power receiving auxiliary coil 22. The second shield member 27 is positioned farther from the power transmitting device 10 in the power transmission direction Z than the power receiving coil 21, and is configured so that the power receiving coil 21 is located between the second shield member 27 and the power transmitting device 10 in the power transmission direction Z. The first power receiving auxiliary coil 22 is positioned between the power receiving coil 21 and the second shield member 27 in the power transmission direction Z. With this configuration, for example, the current flowing through the first power receiving auxiliary coil 22 is opposite in phase to the current flowing through the power receiving coil 21, thereby suppressing a magnetic field incident on the second shield member 27. As a result, the power receiving device 20 can be realized in which shielding loss caused by eddy currents generated when a magnetic field enters the second shield member 27 can be suppressed.

[0091] The second shield member 27 includes a second magnetic member 273 provided in a portion facing the power receiving coil 21 in the power transmission direction Z. With this configuration, it is possible to realize the power receiving device 20 that can more reliably suppress shield loss.

[0092] The system 1 of the second embodiment can achieve the following effects.

[0093] The system 1 includes a power transmitting device 10 and a power receiving device 20 capable of receiving power wirelessly transmitted from the power transmitting device 10 along a power transmission direction Z. The power transmitting device 10 includes a power transmitting coil 11, a first shield member 17, and a first power transmitting auxiliary coil 12. The first shield member 17 is positioned farther from the power receiving device 20 in the power transmission direction Z than the power transmitting coil 11, and is configured so that the power transmitting coil 11 is located between the first shield member 17 and the power receiving device 20 in the power transmission direction Z. The first power transmitting auxiliary coil 12 is positioned between the power transmitting coil 11 and the first shield member 17 in the power transmission direction Z. The power receiving device 20 includes a power receiving coil 21, a second shield member 27, and a first power receiving auxiliary coil 22. The second shield member 27 is positioned farther from the power transmitting device 10 in the power transmission direction Z than the power receiving coil 21, and is configured so that the power receiving coil 21 is located between the second shield member 27 and the power transmitting device 10 in the power transmission direction Z. The first power-receiving auxiliary coil 22 is located between the power-receiving coil 21 and the second shield member 27 in the power transmission direction Z. This configuration makes it possible to realize the system 1 that can suppress shield loss caused by eddy currents that are generated when a magnetic field is incident on the first shield member 17 and / or the second shield member 27.

[0094] The system 1, the power transmitting device 10, and the power receiving device 20 of the second embodiment can be configured as follows.

[0095] 10 and 11 , the power transmitting core 18 may include a first protrusion 182 that protrudes from a first main body portion 181 in the power transmitting direction Z. The first protrusion 182 is located outside the power transmitting coil 11 in a direction intersecting the power transmitting direction Z, and extends from the first main body portion 181 in the power transmitting direction Z and in a direction approaching the power transmitting coil 11. In the system 1 shown in FIGS. 10 and 11 , the first protrusion 182 surrounds the entire circumference of the power transmitting coil 11 around the power transmitting direction Z, but this is not limited to this. The power transmitting core 18 may be configured so that the first protrusion 182 surrounds a portion of the power transmitting coil 11 or so that the first protrusion 182 surrounds the power transmitting coil 11 intermittently.

[0096] The power receiving core 28 can be configured similarly to the power transmitting core 18. That is, the power receiving core 28 may include a second protrusion 282 protruding from the second main body 281 in the power transmission direction Z. The second protrusion 282 is located outside the power receiving coil 21 in a direction intersecting the power transmission direction Z and extends from the second main body 281 in the power transmission direction Z and in a direction approaching the power receiving coil 21. In the systems 1 shown in FIGS. 10 and 11 , the second protrusion 282 surrounds the entire circumference of the power receiving coil 21 around the power transmission direction Z, but this is not limiting. The power receiving core 28 may be configured so that the second protrusion 282 surrounds a portion of the power receiving coil 21 or so that the second protrusion 282 surrounds the power receiving coil 21 intermittently.

[0097] The power transmitting device 10 is not limited to having only the first power transmitting auxiliary coil 12, but may also have multiple power transmitting auxiliary coils. The multiple power transmitting auxiliary coils are arranged, for example, between the power transmitting coil 11 and the first shield member 17 in the power transmission direction Z and / or outside the power transmitting coil 11 in a direction intersecting the power transmission direction Z. Similarly, the power receiving device 20 is not limited to having only the first power receiving auxiliary coil 22, but may also have multiple power receiving auxiliary coils. The multiple power receiving auxiliary coils are arranged, for example, between the power receiving coil 21 and the second shield member 27 in the power transmission direction Z and / or outside the power receiving coil 21 in a direction intersecting the power transmission direction Z.

[0098] The power transmitting device 10 may include a control device 14 capable of controlling the current flowing through the first auxiliary power transmitting coil 12. Similarly, the power receiving device 20 may include a control device 24 capable of controlling the current flowing through the first auxiliary power receiving coil 22.

[0099] The power transmission core 18 and the power receiving core 28 may be omitted.

[0100] The first shield member 17 may not include the first magnetic member 173. The second shield member 27 may not include the second magnetic member 273.

[0101] The first magnetic member 173 and the second magnetic member 273 can be made of any material, not limited to ferrite. The thickness of the first magnetic member 173 and the second magnetic member 273 can be set to any size depending on the design of the power transmitting device 10 or the power receiving device 20.

[0102] The first magnetic member 173 may be provided on all or part of the portion of the first member 171 of the first shield member 17 that faces the power transmitting coil 11 in the power transmission direction Z. The second magnetic member 273 may be provided on all or part of the portion of the third member 271 that faces the power receiving coil 21 in the power transmission direction Z.

[0103] As shown in Figures 14 to 18, the first shielding member 17 may be configured to include a first member 171 and a second member 172, and the second shielding member 27 may be configured to include a third member 271 and a fourth member 272.

[0104] The first member 171 is configured to overlap the power transmission core 18 when viewed along the power transmission direction Z. In this embodiment, the first member 171 has a substantially rectangular plate shape and is made of, for example, a non-magnetic material (e.g., aluminum or copper). The first member 171 is configured such that the power transmission core 18 is located inside the outline of the first member 171 when viewed along the power transmission direction Z.

[0105] The second member 172 is located outside the power transmission core 18 in a direction intersecting the power transmission direction Z and extends from the first member 171 in the power transmission direction Z toward the power transmission core 18. In this embodiment, the second member 172 is formed of, for example, a non-magnetic material (e.g., aluminum or copper). The second member 172 extends from the first member 171 to a portion of the power transmission coil 11 facing the power receiving device 20. However, this is not limited thereto. The second member 172 may be configured to extend from the first member 171 to a position closer to the power receiving device 20 than the power transmission coil 11, or may be configured to extend from the first member 171 to a position farther from the power receiving device 20 than the power transmission coil 11. The second member 172 surrounds the power transmission coil 11 and the power transmission core 18 around the power transmission direction Z around the entire circumference of the power transmission core 18, but is not limited thereto. The first shield member 17 may be configured so that the second member 172 surrounds a portion of the power transmission coil 11 and the power transmission core 18 , or so that the second member 172 surrounds the power transmission coil 11 and the power transmission core 18 intermittently.

[0106] The third member 271 is configured to overlap the power receiving core 28 when viewed along the power transmission direction Z. In this embodiment, the third member 271 has a substantially rectangular plate shape and is made of, for example, a non-magnetic material (e.g., aluminum or copper). The third member 271 is configured such that the power receiving core 28 is located inside the outline of the third member 271 when viewed along the power transmission direction Z.

[0107] The fourth member 272 is located outside the power receiving core 28 in a direction intersecting the power transmission direction Z and extends from the third member 271 in the power transmission direction Z toward the power receiving core 28. In this embodiment, the fourth member 272 is formed of, for example, a non-magnetic material (e.g., aluminum or copper). The fourth member 272 extends from the third member 271 to a portion of the power receiving coil 21 facing the power transmission device 10, but is not limited to this. The fourth member 272 may be configured to extend from the third member 271 to a position closer to the power transmission device 10 than the power receiving coil 21, or may be configured to extend from the third member 271 to a position farther from the power transmission device 10 than the power receiving coil 21. The fourth member 272 surrounds the power receiving coil 21 and the power receiving core 28 around the power transmission direction Z around the entire circumference of the power receiving core 28, but is not limited to this. The second shield member 27 may be configured so that the fourth member 272 surrounds a portion of the power receiving coil 21 and the power receiving core 28 , or so that the fourth member 272 surrounds the power receiving coil 21 and the power receiving core 28 intermittently.

[0108] In the system 1 of Fig. 14 , the first shield member 17 does not include a first magnetic member 173, and the second shield member 27 does not include a second magnetic member 273. In the system 1 of Fig. 15 , the first magnetic member 173 is provided at the tip portion 175 of the first shield member 17, and the second magnetic member 273 is provided at the tip portion 275 of the second shield member 27. In the system 1 of Fig. 16 , the first magnetic member 173 is provided at the inner portion 174 of the first shield member 17, and the second magnetic member 273 is provided at the inner portion 274 of the second shield member 27. In the system 1 of Fig. 17 , the first magnetic member 173 is provided at the bottom portion 176 of the first shield member 17, and the second magnetic member 273 is provided at the bottom portion 276 of the second shield member 27. In the system 1 of Figure 18, a first magnetic member 173 is provided on a portion of the tip 175 and a portion of the inner portion 174 of the first shield member 17, and a second magnetic member 273 is provided on a portion of the tip 275 and a portion of the bottom 276 of the second shield member 27.

[0109] That is, the first magnetic member 173 does not have to be provided on the first shield member 17, or may be provided on one or more of the inner portion 174, the tip portion 175, and the bottom portion 176 of the first shield member 17. The second magnetic member 273 does not have to be provided on the second shield member 27, or may be provided on one or more of the inner portion 274, the tip portion 275, and the bottom portion 276 of the second shield member 27.

[0110] The first shield member 17, the second shield member 27, the power transmission core 18, and the power receiving core 28 can be applied to the power transmission device 10 and the power receiving device 20 of the first embodiment. The power transmission core 18 and the power receiving core 28 can be applied to the power transmission device 10 and the power receiving device 20 of the third embodiment.

[0111] A second embodiment of the present disclosure is described below with reference numerals.

[0112] The power transmission device 10 of the first aspect of the second embodiment is a power transmission device 10 capable of wirelessly transmitting power to a power receiving device 20 along a power transmission direction, and comprises: a power transmission coil 11; a first shield member 17 that is positioned farther from the power receiving device 20 in the power transmission direction than the power transmission coil 11 and that is positioned between the power transmission coil 11 and the power receiving device 20 in the power transmission direction; and a power transmission auxiliary coil that is positioned between the power transmission coil 11 and the first shield member 17 in the power transmission direction.

[0113] The power transmission device 10 of the second aspect of the second embodiment is the power transmission device 10 of the first aspect, and further comprises a power transmission core 18 located between the power transmission coil 11 and the power transmission auxiliary coil in the power transmission direction, and the power transmission core 18 includes: a first main body portion 181 configured to overlap the power transmission coil 11 when viewed along the power transmission direction; and a first protrusion portion 182 located outside the power transmission coil 11 in a direction intersecting the power transmission direction, and extending from the first main body portion 181 in the power transmission direction and in a direction approaching the power transmission coil 11.

[0114] The third aspect of the second embodiment is the power transmission device 10 of the first or second aspect, wherein the first shield member 17 includes a first magnetic member 173 provided in a portion facing the power transmission coil 11 in the power transmission direction.

[0115] A fourth aspect of the second embodiment of the power transmission device 10 is the power transmission device 10 of the first or second aspect, wherein the first shield member 17 includes a first member 171 configured to overlap the power transmission core 18 when viewed along the power transmission direction, and a second member 172 positioned outside the power transmission core 18 in a direction intersecting the power transmission direction and extending from the first member 171 in the power transmission direction and in a direction approaching the power transmission core 18.

[0116] A fifth aspect of the power transmitting device 10 of the second embodiment is the power transmitting device 10 of the fourth aspect, wherein the first shield member 17 includes a first magnetic member 173 .

[0117] The sixth aspect of the second embodiment is the power transmission device 10 of the fifth aspect, wherein the first magnetic member 173 is provided in a portion of the first member 171 that faces the power transmission coil 11 in the power transmission direction.

[0118] The seventh aspect of the second embodiment of the power transmission device 10 is the power transmission device 10 of the fifth or sixth aspect, wherein the first magnetic member 173 is provided at a portion of the second member 172 that faces the power transmission core 18 in a direction intersecting the power transmission direction.

[0119] The eighth aspect of the second embodiment is a power transmission device 10 of any of the fifth to seventh aspects, wherein the first magnetic member 173 is provided in a portion of the second member 172 that faces the power receiving device 20 in the power transmission direction.

[0120] The power receiving device 20 of the ninth aspect of the second embodiment is a power receiving device 20 capable of receiving power transmitted wirelessly from the power transmitting device 10 along the power transmission direction, and comprises: a power receiving coil 21; a second shield member 27 that is positioned farther from the power transmitting device 10 in the power transmission direction than the power receiving coil 21 and between the power receiving coil 21 and the power transmitting device 10 in the power transmission direction; and a power receiving auxiliary coil that is positioned between the power receiving coil 21 and the second shield member 27 in the power transmission direction.

[0121] The power receiving device 20 of a tenth aspect of the second embodiment is the power receiving device 20 of the ninth aspect, and further comprises a power receiving core 28 located between the power receiving coil 21 and the power receiving auxiliary coil in the power transmission direction, and the power receiving core 28 includes: a second main body portion 281 configured to overlap the power receiving coil 21 when viewed along the power transmission direction; and a second protrusion portion 282 located outside the power receiving coil 21 in a direction intersecting the power transmission direction and extending from the second main body portion 281 in the power transmission direction and in a direction approaching the power receiving coil 21.

[0122] The power receiving device 20 of an eleventh aspect of the second embodiment is the power receiving device 20 of the ninth or tenth aspect, wherein the second shield member 27 includes a second magnetic member 273 provided in a portion facing the power receiving coil 21 in the power transmission direction.

[0123] The power receiving device 20 of a twelfth aspect of the second embodiment is the power receiving device 20 of the ninth or tenth aspect, wherein the second shield member 27 includes a third member 271 configured to overlap the power receiving core 28 when viewed along the power transmission direction, and a fourth member 272 positioned outside the power receiving core 28 in a direction intersecting the power transmission direction and extending from the third member 271 in the power transmission direction and in a direction approaching the power receiving core 28.

[0124] The power receiving device 20 of a thirteenth aspect of the second embodiment is the power receiving device 20 of the twelfth aspect, wherein the second shield member 27 includes a second magnetic member 273 .

[0125] The power receiving device 20 of a fourteenth aspect of the second embodiment is the power receiving device 20 of the thirteenth aspect, wherein the second magnetic member 273 is provided in a portion of the third member 271 that faces the power receiving coil 21 in the power transmission direction.

[0126] The seventh aspect of the second embodiment is a power receiving device 20 of the fifth or sixth aspect, in which the second magnetic member 273 is provided in a portion of the fourth member 272 that faces the power receiving core 28 in a direction that intersects the power transmission direction.

[0127] The power receiving device 20 of the eighth aspect of the second embodiment is a power receiving device 20 of any of the fifth to seventh aspects, in which the second magnetic member 273 is provided in a portion of the fourth member 272 that faces the power transmitting device 10 in the power transmission direction.

[0128] The system 1 of the seventeenth aspect of the second embodiment comprises a power transmission device 10 and a power receiving device 20 capable of receiving power transmitted wirelessly from the power transmission device 10 along the power transmission direction, wherein the power transmission device 10 includes a power transmission coil 11, a first shield member 17 positioned farther from the power receiving device 20 in the power transmission direction than the power transmission coil 11 and between the power transmission coil 11 and the power receiving device 20 in the power transmission direction, and a power transmission auxiliary coil positioned between the power transmission coil 11 and the first shield member 17 in the power transmission direction, and the power receiving device 20 includes a power receiving coil 21, a second shield member 27 positioned farther from the power transmission device 10 in the power transmission direction than the power receiving coil 21 and between the power receiving coil 21 and the power transmission device 10 in the power transmission direction, and a power receiving auxiliary coil positioned between the power receiving coil 21 and the second shield member 27 in the power transmission direction.

[0129] 12 and 13 , a power transmission device 10 of a system 1 of a third embodiment includes a power transmission coil 11, a first shield member 17, and a power transmission core 18. The first shield member 17 is positioned farther from the power receiving device 20 in the power transmission direction Z than the power transmission coil 11, and is configured so that the power transmission coil 11 is positioned between the power receiving device 20 in the power transmission direction Z. The power transmission core 18 is positioned between the power transmission coil 11 and the first shield member 17 in the power transmission direction Z.

[0130] The first shield member 17 includes a first member 171 , a second member 172 , and a first magnetic member 173 .

[0131] The first member 171 is configured to overlap the power transmission core 18 when viewed along the power transmission direction Z. In this embodiment, the first member 171 has a substantially rectangular plate shape and is made of, for example, a non-magnetic material (e.g., aluminum or copper). The first member 171 is configured such that the power transmission core 18 is located inside the outline of the first member 171 when viewed along the power transmission direction Z.

[0132] The second member 172 is located outside the power transmission core 18 in a direction intersecting the power transmission direction Z and extends from the first member 171 in the power transmission direction Z toward the power transmission core 18. In this embodiment, the second member 172 is formed of, for example, a non-magnetic material (e.g., aluminum or copper). The second member 172 extends from the first member 171 to a portion of the power transmission coil 11 facing the power receiving device 20, but is not limited to this. The second member 172 may be configured to extend from the first member 171 to a position closer to the power receiving device 20 than the power transmission coil 11, or may be configured to extend from the first member 171 to a position farther from the power receiving device 20 than the power transmission coil 11. The second member 172 surrounds the power transmission coil 11 and the power transmission core 18 around the power transmission direction Z around the entire circumference of the power transmission core 18, but is not limited to this. The first shield member 17 may be configured so that the second member 172 surrounds a portion of the power transmission coil 11 and the power transmission core 18 , or so that the second member 172 surrounds the power transmission coil 11 and the power transmission core 18 intermittently.

[0133] The first magnetic member 173 is provided on the first member 171 and the second member 172. Specifically, the first magnetic member 173 is provided on a portion of the first member 171 facing the power transmission core 18 in the power transmission direction Z (hereinafter referred to as a bottom portion 176 of the first shield member 17), a portion of the second member 172 facing the power transmission core 18 in a direction intersecting the power transmission direction Z (hereinafter referred to as an inner portion 174 of the first shield member 17), and a portion facing the power receiving device 20 in the power transmission direction Z (hereinafter referred to as a tip portion 175 of the first shield member 17). In this embodiment, the first magnetic member 173 is provided over the entire bottom portion 176, the inner portion 174, and the tip portion 175, but is not limited to this. The first magnetic member 173 may be provided on parts of the bottom portion 176, the inner portion 174, and the tip portion 175.

[0134] In this embodiment, the first magnetic member 173 has a thickness smaller than that of the power transmission core 18. For example, the thicknesses of the first magnetic member 173 provided at the bottom portion 176 and the tip portion 175 are the dimensions of each portion of the first magnetic member 173 in the power transmission direction Z. The thickness of the power transmission core 18 is the dimension of the power transmission core 18 in the power transmission direction Z. The thickness of the first magnetic member 173 provided at the inner portion 174 is the dimension of the inner portion 174 in a direction intersecting the power transmission direction Z (for example, the X direction).

[0135] The power receiving device 20 of the system 1 of the third embodiment includes a power receiving coil 21, a second shield member 27, and a power receiving core 28. The second shield member 27 is positioned farther from the power transmitting device 10 in the power transmission direction Z than the power receiving coil 21, and is configured so that the power receiving coil 21 is located between the power receiving coil 21 and the power transmitting device 10 in the power transmission direction Z. The power receiving core 28 is positioned between the power receiving coil 21 and the second shield member 27 in the power transmission direction Z.

[0136] The second shield member 27 includes a third member 271 , a fourth member 272 , and a second magnetic member 273 .

[0137] The third member 271 is configured to overlap the power receiving core 28 when viewed along the power transmission direction Z. In this embodiment, the third member 271 has a substantially rectangular plate shape and is made of, for example, a non-magnetic material (e.g., aluminum or copper). The third member 271 is configured such that the power receiving core 28 is located inside the outline of the third member 271 when viewed along the power transmission direction Z.

[0138] The fourth member 272 is located outside the power receiving core 28 in a direction intersecting the power transmission direction Z and extends from the third member 271 in the power transmission direction Z toward the power receiving core 28. In this embodiment, the fourth member 272 is formed of, for example, a non-magnetic material (e.g., aluminum or copper). The fourth member 272 extends from the third member 271 to a portion of the power receiving coil 21 facing the power transmission device 10, but is not limited to this. The fourth member 272 may be configured to extend from the third member 271 to a position closer to the power transmission device 10 than the power receiving coil 21, or may be configured to extend from the third member 271 to a position farther from the power transmission device 10 than the power receiving coil 21. The fourth member 272 surrounds the power receiving coil 21 and the power receiving core 28 around the power transmission direction Z around the entire circumference of the power receiving core 28, but is not limited to this. The second shield member 27 may be configured so that the fourth member 272 surrounds a portion of the power receiving coil 21 and the power receiving core 28 , or so that the fourth member 272 surrounds the power receiving coil 21 and the power receiving core 28 intermittently.

[0139] The second magnetic member 273 is provided on the third member 271 and the fourth member 272. Specifically, the second magnetic member 273 is provided on a portion of the third member 271 facing the power receiving core 28 in the power transmission direction Z (hereinafter referred to as a bottom portion 276 of the second shield member 27), a portion of the fourth member 272 facing the power receiving core 28 in a direction intersecting the power transmission direction Z (hereinafter referred to as an inner portion 274 of the second shield member 27), and a portion facing the power transmitting device 10 in the power transmission direction Z (hereinafter referred to as a tip portion 275 of the second shield member 27). In this embodiment, the second magnetic member 273 is provided over the entire bottom portion 276, inner portion 274, and tip portion 275, but is not limited thereto. The first magnetic member 273 may be provided on parts of the bottom portion 276, inner portion 274, and tip portion 275.

[0140] In this embodiment, the second magnetic member 273 has a thickness smaller than that of the power receiving core 28. For example, the thicknesses of the second magnetic member 273 provided at the bottom portion 276 and the tip portion 275 are the dimensions of each portion of the second magnetic member 273 in the power transmission direction Z. The thickness of the power receiving core 28 is the dimension of the power receiving core 28 in the power transmission direction Z. The thickness of the second magnetic member 273 provided at the inner portion 274 is the dimension of the inner portion 274 in a direction intersecting the power transmission direction Z (for example, the X direction).

[0141] The power transmission device 10 of the third embodiment can achieve the following effects.

[0142] The power transmitting device 10 is capable of wirelessly transmitting power to the power receiving device 20 along the power transmission direction Z, and includes a power transmitting coil 11, a first shield member 17, and a power transmitting core 18. The first shield member 17 is positioned farther from the power receiving device 20 in the power transmission direction Z than the power transmitting coil 11, and is configured so that the power transmitting coil 11 is positioned between the power transmitting coil 11 and the power receiving device 20 in the power transmission direction Z. The power transmitting core 18 is positioned between the power transmitting coil 11 and the first shield member 17 in the power transmission direction Z. The first shield member 17 includes a first member 171, a second member 172, and first magnetic members 173 provided on the first member 171 and the second member 172. The first member 171 is configured to overlap with the power transmitting core 18 when viewed along the power transmission direction Z. The second member 172 is located outside the power transmission core 18 in a direction intersecting the power transmission direction Z and extends from the first member 171 in the power transmission direction Z toward the power transmission core 18. The first magnetic member 173 is provided on a portion of the first member 171 facing the power transmission core 18 in the power transmission direction Z, and on a portion of the second member 172 facing the power transmission core 18 in a direction intersecting the power transmission direction Z and facing the power receiving device 20 in the power transmission direction Z. With this configuration, the first member 171 and the second member 172 reduce the leakage magnetic field, while the first magnetic member 173 guides the magnetic flux toward the inside of the power transmission coil 11, thereby improving the coupling coefficient. As a result, a power transmitting device 10 can be realized that can reduce the leakage magnetic field while maintaining WPT (wireless power transmission) efficiency.

[0143] The first magnetic member 173 has a thickness smaller than that of the power transmission core 18. With this configuration, the manufacturing cost of the power transmission device 10 can be reduced.

[0144] The power receiving device 20 of the third embodiment can achieve the following effects.

[0145] The power receiving device 20 is capable of receiving power wirelessly transmitted from the power transmitting device 10 along the power transmission direction, and includes a power receiving coil 21, a second shield member 27, and a power receiving core 28. The second shield member 27 is positioned farther from the power transmitting device 10 in the power transmission direction Z than the power receiving coil 21, and is configured so that the power receiving coil 21 is located between the second shield member 27 and the power transmitting device 10 in the power transmission direction Z. The power receiving core 28 is positioned between the power receiving coil 21 and the second shield member 27 in the power transmission direction Z. The second shield member 27 includes a third member 271, a fourth member 272, and second magnetic members 273 provided on the third member 271 and the fourth member 272. The third member 271 is configured to overlap with the power receiving core 28 when viewed along the power transmission direction Z. The fourth member 272 is located outside the power receiving core 28 in a direction intersecting the power transmission direction Z and extends from the third member 271 in the power transmission direction Z toward the power receiving core 28. The second magnetic member 273 is provided on a portion of the third member 271 facing the power receiving core 28 in the power transmission direction Z and on a portion of the fourth member 272 facing the power receiving core 28 in a direction intersecting the power transmission direction Z and facing the power transmitting device 10 in the power transmission direction Z. With this configuration, the third member 271 and the fourth member 272 reduce the leakage magnetic field, while the second magnetic member 273 guides the magnetic flux toward the inside of the power transmitting coil 11, thereby improving the coupling coefficient. As a result, a power transmitting device 10 can be realized that can reduce the leakage magnetic field while maintaining WPT efficiency.

[0146] The second magnetic member 273 has a thickness smaller than that of the power receiving core 28. With this configuration, the manufacturing cost of the power receiving device 20 can be reduced.

[0147] The system 1 of the third embodiment can achieve the following effects.

[0148] The system 1 includes a power transmitting device 10 and a power receiving device 20 capable of receiving power wirelessly transmitted from the power transmitting device 10 along a power transmission direction Z. The power transmitting device 10 includes a power transmitting coil 11, a first shield member 17, and a power transmitting core 18. The first shield member 17 is positioned farther from the power receiving device 20 in the power transmission direction Z than the power transmitting coil 11, and is configured so that the power transmitting coil 11 is positioned between the power transmitting coil 11 and the power receiving device 20 in the power transmission direction Z. The power transmitting core 18 is positioned between the power transmitting coil 11 and the first shield member 17 in the power transmission direction Z. The first shield member 17 includes a first member 171, a second member 172, and first magnetic members 173 provided on the first member 171 and the second member 172. The first member 171 is configured to overlap with the power transmitting core 18 when viewed along the power transmission direction Z. The second member 172 is located outside the power transmission core 18 in a direction intersecting the power transmission direction Z and extends from the first member 171 in the power transmission direction Z toward the power transmission core 18. The first magnetic member 173 is provided on a portion of the first member 171 facing the power transmission core 18 in the power transmission direction Z, and on a portion of the second member 172 facing the power transmission core 18 in a direction intersecting the power transmission direction Z and facing the power receiving device 20 in the power transmission direction Z. The power receiving device 20 includes a power receiving coil 21, a second shield member 27, and a power receiving core 28. The second shield member 27 is located farther from the power transmitting device 10 in the power transmission direction Z than the power receiving coil 21, and is configured so that the power receiving coil 21 is located between the second shield member 27 and the power transmitting device 10 in the power transmission direction Z. The power receiving core 28 is located between the power receiving coil 21 and the second shield member 27 in the power transmission direction Z. The second shield member 27 includes a third member 271, a fourth member 272, and a second magnetic member 273 provided on the third member 271 and the fourth member 272. The third member 271 is configured to overlap the power receiving core 28 when viewed along the power transmission direction Z. The fourth member 272 is located outside the power receiving core 28 in a direction intersecting the power transmission direction Z, and extends from the third member 271 in the power transmission direction Z in a direction approaching the power receiving core 28.The second magnetic member 273 is provided on a portion of the third member 271 facing the power receiving core 28 in the power transmission direction Z, and on a portion of the fourth member 272 facing the power receiving core 28 in a direction intersecting the power transmission direction Z and facing the power transmitter 10 in the power transmission direction Z. This configuration makes it possible to realize a system 1 that can reduce leakage magnetic fields while ensuring WPT efficiency.

[0149] The system 1, the power transmitting device 10, and the power receiving device 20 of the third embodiment can be configured as follows.

[0150] The power transmitting device 10 may include a first auxiliary power transmitting coil 12 (see FIG. 11 ) located between the first shield member 17 and the power transmitting core 18 in the power transmission direction Z. This configuration makes it possible to realize the power transmitting device 10 that can suppress shield loss caused by eddy currents that are generated when a magnetic field is incident on the first shield member 17.

[0151] The power transmitting device 10 may include a plurality of auxiliary power transmitting coils. The auxiliary power transmitting coils are arranged, for example, between the power transmitting coil 11 and the first shield member 17 in the power transmitting direction Z and / or outside the power transmitting coil 11 in a direction intersecting the power transmitting direction Z.

[0152] The power receiving device 20 may include a first power receiving auxiliary coil 22 (see FIG. 11 ) located between the second shield member 27 and the power receiving core 28 in the power transmission direction Z. This configuration makes it possible to realize the power receiving device 20 that can suppress shield loss caused by eddy currents that are generated when a magnetic field enters the second shield member 27.

[0153] The power receiving device 20 may include a plurality of auxiliary power receiving coils. The auxiliary power receiving coils are arranged, for example, between the power receiving coil 21 and the second shield member 27 in the power transmission direction Z and / or outside the power receiving coil 21 in a direction intersecting the power transmission direction Z.

[0154] The power transmitting device 10 may include a control device 14 (see FIG. 1 ) capable of controlling the current flowing through the auxiliary power transmitting coil. Similarly, the power receiving device 20 may include a control device 24 (see FIG. 1 ) capable of controlling the current flowing through the auxiliary power receiving coil.

[0155] The first magnetic member 173 does not necessarily have a thickness smaller than the power transmission core 18, but may have a thickness the same as or greater than the power transmission core 18. Similarly, the second magnetic member 273 does not necessarily have a thickness smaller than the power receiving core 28, but may have a thickness the same as or greater than the power receiving core 28.

[0156] The first shield member 17 and the second shield member 27 can be applied to the power transmitting device 10 and the power receiving device 20 of the first and second embodiments.

[0157] 19 to 23 , the first shield member 17 may not include the first magnetic member 173, or may include one or more of the inner portion 174, the tip portion 175, and the bottom portion 176 of the first shield member 17. The second shield member 27 may not include the second magnetic member 273, or may include one or more of the inner portion 274, the tip portion 275, and the bottom portion 276 of the second shield member 27.

[0158] In the system 1 of Fig. 19, the first shield member 17 does not include a first magnetic member 173, and the second shield member 27 does not include a second magnetic member 273. In the system 1 of Fig. 20, the first magnetic member 173 is provided at the tip portion 175 of the first shield member 17, and the second magnetic member 273 is provided at the tip portion 275 of the second shield member 27. In the system 1 of Fig. 21, the first magnetic member 173 is provided at the inner portion 174 of the first shield member 17, and the second magnetic member 273 is provided at the inner portion 274 of the second shield member 27. In the system 1 of Fig. 22, the first magnetic member 173 is provided at the bottom portion 176 of the first shield member 17, and the second magnetic member 273 is provided at the bottom portion 276 of the second shield member 27. In system 1 of Figure 23, a first magnetic member 173 is provided on a part of the inner portion 174 and a part of the bottom portion 176 of the first shield member 17, and a second magnetic member 273 is provided on a part of the inner portion 274, a part of the tip portion 275, and a part of the bottom portion 276 of the second shield member 27.

[0159] A third embodiment of the present disclosure is described below with reference numerals.

[0160] a power transmission device (10) according to a first-1 aspect of the third embodiment, which is capable of wirelessly transmitting power to a power receiving device (20) along a power transmission direction, and which includes: a power transmission coil (11); a first shield member (17) positioned farther from the power receiving device (20) than the power transmission coil (11) in the power transmission direction, and between which the power transmission coil (11) is positioned and the power receiving device (20) in the power transmission direction; and a power transmission core (18) positioned between the power transmission coil (11) and the first shield member (17) in the power transmission direction, wherein the first shield member (17) includes: a first member (171) configured to overlap with the power transmission core (18) when viewed along the power transmission direction; a second member (172) positioned outside the power transmission core (18) in a direction intersecting the power transmission direction, and extending from the first member (171) in the power transmission direction and in a direction approaching the power transmission core (18); and a first magnetic member (173) provided on the first member (171) and the second member (172), The first magnetic member 173 is provided on a portion of the first member 171 that faces the power transmission core 18 in the power transmission direction, and on a portion of the second member 172 that faces the power transmission core 18 in a direction intersecting the power transmission direction and that faces the power receiving device 20 in the power transmission direction.

[0161] The power transmission device 10 of the second-first aspect of the third embodiment is the power transmission device 10 of the first-first aspect, further comprising a first auxiliary power transmission coil 12 positioned between the first shield member 17 and the power transmission core 18 in the power transmission direction.

[0162] The power transmission device 10 of a 3-1 aspect of the third embodiment is the power transmission device 10 of the 1-1 or 2-1 aspect, wherein the first magnetic member 173 has a thickness smaller than that of the power transmission core 18 .

[0163] a power receiving device 20 according to a fourth-1 aspect of the third embodiment, which is capable of receiving power wirelessly transmitted from a power transmitting device 10 along a power transmission direction, and includes: a power receiving coil 21; a second shield member 27 located farther from the power transmitting device 10 in the power transmission direction than the power receiving coil 21, and between which the power receiving coil 21 is located and the power transmitting device 10 in the power transmission direction; and a power receiving core 28 located between the power receiving coil 21 and the second shield member 27 in the power transmission direction, wherein the second shield member 27 includes: a third member 271 configured to overlap with the power receiving core 28 when viewed along the power transmission direction; a fourth member 272 located outside the power receiving core 28 in a direction intersecting the power transmission direction, and extending from the third member 271 in the power transmission direction and in a direction approaching the power receiving core 28; and second magnetic members 273 provided on the third member 271 and the fourth member 272. The second magnetic member 273 is provided on a portion of the third member 271 facing the power receiving core 28 in the power transmission direction, and on a portion of the fourth member 272 facing the power receiving core 28 in a direction intersecting the power transmission direction and facing the power transmitting device 10 in the power transmission direction.

[0164] The power receiving device 20 of the 5-1 aspect of the third embodiment is the power receiving device 20 of the 4-1 aspect, and further includes a first power receiving auxiliary coil 22 positioned between the second shield member 27 and the power receiving core 28 in the power transmission direction.

[0165] The power receiving device 20 of a 6-1 aspect of the third embodiment is the power receiving device 20 of the 4-1 or 5-1 aspect, wherein the second magnetic member 273 has a thickness smaller than that of the power receiving core 28 .

[0166] A system 1 of a 7-1 aspect of the third embodiment comprises: a power transmission device 10; and a power receiving device 20 capable of receiving power transmitted wirelessly from the power transmission device 10 along a power transmission direction, wherein the power transmission device 10 comprises: a power transmission coil 11; a first shield member 17 located farther from the power receiving device 20 in the power transmission direction than the power transmission coil 11 is, and between the power transmission coil 11 and the power receiving device 20 in the power transmission direction; and a power transmission core 18 located between the power transmission coil 11 and the first shield member 17 in the power transmission direction, wherein the first shield member 17 comprises: a first member 171 configured to overlap with the power transmission core 18 when viewed along the power transmission direction; and a second member 172 located outside the power transmission core 18 in a direction intersecting the power transmission direction, and extending from the first member 171 in the power transmission direction and in a direction approaching the power transmission core 18; and a first magnetic member 173 provided on the first member 171 and the second member 172, wherein the first magnetic member 173 is provided on a portion of the first member 171 facing the power transmission core 18 in the power transmission direction, and on a portion of the second member 172 facing the power transmission core 18 in a direction intersecting the power transmission direction and facing the power receiving device 20 in the power transmission direction, wherein the power receiving device 20 comprises: a power receiving coil 21; a second shield member 27 located farther from the power transmitting device 10 in the power transmission direction than the power receiving coil 21 and between the power receiving coil 21 and the power transmitting device 10 in the power transmission direction; and a power receiving core 28 located between the power receiving coil 21 and the second shield member 27 in the power transmission direction, wherein the second shield member 27 is configured to overlap with the power receiving core when viewed along the power transmission direction; a fourth member (272) positioned outside the power receiving core (28) in a direction intersecting the power transmission direction and extending from the third member (271) in the power transmission direction and in a direction approaching the power receiving core (28); and a second magnetic member (273) provided on the third member (271) and the fourth member (272),The second magnetic member 273 is provided on a portion of the third member 271 that faces the receiving core 28 in the power transmission direction, and on a portion of the fourth member 272 that faces the receiving core 28 in a direction intersecting the power transmission direction and that faces the power transmission device 10 in the power transmission direction.

[0167] The power transmission device 10 of the first-2 aspect of the third embodiment is a power transmission device 10 capable of wirelessly transmitting power to a power receiving device 20 along a power transmission direction, and comprises: a power transmission coil 11; a first shield member 17 that is positioned farther from the power receiving device 20 in the power transmission direction than the power transmission coil 11 and between the power receiving device 20 in the power transmission direction, and a power transmission core 18 that is positioned between the power transmission coil 11 and the first shield member 17 in the power transmission direction, wherein the first shield member 17 includes: a first member 171 configured to overlap with the power transmission core 18 when viewed along the power transmission direction; and a second member 172 that is positioned outside the power transmission core 18 in a direction intersecting the power transmission direction and extends from the first member 171 in the power transmission direction and in a direction approaching the power transmission core 18.

[0168] The power transmitting device 10 of a second-second aspect of the third embodiment is the power transmitting device 10 of the second-first aspect, wherein the first shield member 17 includes a first magnetic member 173 .

[0169] The power transmission device 10 of aspect 3-2 of the third embodiment is the power transmission device 10 of aspect 2-2, in which the first magnetic member 173 is provided in a portion of the first member 171 that faces the power transmission coil 11 in the power transmission direction.

[0170] The power transmission device 10 of the 4-2 aspect of the third embodiment is the power transmission device 10 of the 2-2 or 3-2 aspect, in which the first magnetic member 173 is provided at a portion of the second member 172 that faces the power transmission core 18 in a direction that intersects the power transmission direction.

[0171] The power transmission device 10 of the 5-2 aspect of the third embodiment is a power transmission device 10 of any of the 2-2 to 4-2 aspects, in which the first magnetic member 173 is provided in a portion of the second member 172 that faces the power receiving device 20 in the power transmission direction.

[0172] The power transmission device 10 of the 6-2 aspect of the third embodiment is the power transmission device 10 of any of the 2-2 to 5-2 aspects, wherein the second magnetic member 273 has a thickness smaller than that of the power receiving core 28.

[0173] The power transmission device 10 of the 7-2 aspect of the third embodiment is a power transmission device 10 of any of the 1-2 to 6-2 aspects, which is provided with a first power receiving auxiliary coil 22 positioned between the second shield member 27 and the power receiving core 28 in the power transmission direction.

[0174] The power receiving device 20 of the 8-2 aspect of the third embodiment is a power receiving device 20 capable of receiving power transmitted wirelessly from a power transmitting device 10 along a power transmission direction, and comprises: a power receiving coil 21; a second shield member 27 that is positioned farther from the power transmitting device 10 in the power transmission direction than the power receiving coil 21, and between which the power receiving coil 21 is positioned and the power transmitting device 10 in the power transmission direction; and a power receiving core 28 that is positioned between the power receiving coil 21 and the second shield member 27 in the power transmission direction, wherein the second shield member 27 includes: a third member 271 configured to overlap with the power receiving core 28 when viewed along the power transmission direction; and a fourth member 272 that is positioned outside the power receiving core 28 in a direction intersecting the power transmission direction and extends from the third member 271 in the power transmission direction and in a direction approaching the power receiving core 28.

[0175] The power receiving device 20 of a 9-2 aspect of the third embodiment is the power receiving device 20 of the 8-2 aspect, wherein the second shield member 27 includes a second magnetic member 273 .

[0176] The power receiving device 20 of aspect 10-2 of the third embodiment is the power receiving device 20 of aspect 9-2, in which the second magnetic member 273 is provided in a portion of the third member 271 that faces the power receiving coil 21 in the power transmission direction.

[0177] The power receiving device 20 of the 11-2 aspect of the third embodiment is the power receiving device 20 of the 9-2 or 10-2 aspect, in which the second magnetic member 273 is provided at a portion of the fourth member 272 that faces the power receiving core 28 in a direction that intersects the power transmission direction.

[0178] The power receiving device 20 of aspect 12-2 of the third embodiment is a power receiving device 20 of any of aspects 9-2 to 11-2, in which the second magnetic member 273 is provided in a portion of the fourth member 272 that faces the power transmitting device 10 in the power transmission direction.

[0179] The power receiving device 20 of a 13-2 aspect of the third embodiment is the power receiving device 20 of any one of the 9-2 to 12-2 aspects, wherein the second magnetic member 273 has a thickness smaller than that of the power receiving core 28 .

[0180] The power receiving device 20 of aspect 14-2 of the third embodiment is a power receiving device 20 of any of aspects 8-2 to 13-2, which is provided with a first power receiving auxiliary coil 22 positioned between the second shield member 27 and the power receiving core 28 in the power transmission direction.

[0181] A system 1 of a 15-2 aspect of the third embodiment comprises: a power transmission device 10; and a power receiving device 20 capable of receiving power transmitted wirelessly from the power transmission device 10 along a power transmission direction, wherein the power transmission device 10 comprises: a power transmission coil 11; a first shield member 17 located farther from the power receiving device 20 in the power transmission direction than the power transmission coil 11 and between the power transmission coil 11 and the power receiving device 20 in the power transmission direction; and a power transmission core 18 located between the power transmission coil 11 and the first shield member 17 in the power transmission direction, wherein the first shield member 17 comprises: a first member 171 configured to overlap with the power transmission core 18 when viewed along the power transmission direction; and a second member 172 located outside the power transmission core 18 in a direction intersecting the power transmission direction and extending from the first member 171 in the power transmission direction and in a direction approaching the power transmission core 18, and wherein the power receiving device 20 comprises: a receiving coil (21); a second shielding member (27) positioned farther from the power transmitting device (10) than the receiving coil (21) in the power transmission direction, with the receiving coil (21) positioned between the receiving coil (21) and the power transmitting device (10) in the power transmission direction; and a receiving core (28) positioned between the receiving coil (21) and the second shielding member (27) in the power transmission direction, wherein the second shielding member (27) includes: a third member (271) configured to overlap with the receiving core when viewed along the power transmission direction; and a fourth member (272) positioned outside the receiving core (28) in a direction intersecting the power transmission direction, and extending from the third member (271) in the power transmission direction and in a direction approaching the receiving core (28).

[0182] Any of the various embodiments or modifications described above can be combined appropriately to achieve the effects of each. In addition, combinations of embodiments, combinations of examples, or combinations of embodiments and examples are possible, and combinations of features from different embodiments or examples are also possible.

[0183] Although the present disclosure has been described in each embodiment with a certain degree of detail, the disclosed contents of these embodiments may vary in structural details, and changes in the combination and order of elements in each embodiment may be made without departing from the scope and spirit of the claimed disclosure.

[0184] The present disclosure is applicable to slip rings used in, for example, moving bodies such as AGVs (automated guided vehicles) or EVs (electric vehicles), pallets used in conveyor lines, and robot arms.

[0185] REFERENCE SIGNS LIST 1 System 10 Power transmitting device 11 Power transmitting coil 12 First auxiliary power transmitting coil 13 Second auxiliary power transmitting coil 14 Control device 15 Third auxiliary power transmitting coil 16 Fourth auxiliary power transmitting coil 17 First shield member 18 Power transmitting core 20 Power receiving device 21 Power receiving coil 22 First auxiliary power receiving coil 23 Second auxiliary power receiving coil 24 Control device 25 Third auxiliary power receiving coil 26 Fourth auxiliary power receiving coil 27 Second shield member 28 Power receiving core 30, 31, 32, 40, 41, 42 Power source 33, 34, 43, 44, 61, 62 Switch 35, 36, 45, 46 Variable capacitor 40, 41, 42 Power source 51, 52 Capacitor 141 Processor 142 Storage device 143 Communication device 171 First member 172 Second member 173 First magnetic member 174 Inner portion 175 Tip portion 176 Bottom portion 181 First main body portion 182 First protrusion portion 241 Processor 242 Storage device 243 Communication device 271 Third member 272 Fourth member 273 Second magnetic member 274 Inner portion 275 Tip portion 276 Bottom portion 281 Second main body portion 282 Second protrusion portion

Claims

1. A power transmission device capable of wirelessly transmitting power to a power receiving device along a power transmission direction, comprising: a power transmission coil; a first shielding member that is positioned farther from the power receiving device in the power transmission direction than the power transmission coil and between the power transmission coil and the power receiving device in the power transmission direction; and a power transmission core that is positioned between the power transmission coil and the first shielding member in the power transmission direction, wherein the first shielding member comprises: a first member configured to overlap with the power transmission core when viewed along the power transmission direction; and a second member that is positioned outside the power transmission core in a direction intersecting the power transmission direction and extends from the first member in the power transmission direction and in a direction approaching the power transmission core.

2. The power transmission device according to claim 1, wherein the first shielding member includes a first magnetic member.

3. The power transmission device according to claim 2, wherein the first magnetic member is provided at a portion of the first member that faces the power transmission coil in the power transmission direction.

4. A power transmission device as described in claim 2 or 3, wherein the first magnetic member is provided at a portion of the second member that faces the power transmission core in a direction intersecting the power transmission direction.

5. A power transmission device according to any one of claims 2 to 4, wherein the first magnetic member is provided on a portion of the second member that faces the power receiving device in the power transmission direction.

6. The power transmission device according to any one of claims 2 to 5, wherein the first magnetic member has a thickness smaller than that of the power transmission core.

7. A power transmitting device according to any one of claims 1 to 6, further comprising a first auxiliary power transmitting coil located between the first shield member and the power transmitting core in the power transmitting direction.

8. A power receiving device capable of receiving power transmitted wirelessly from a power transmitting device along a power transmission direction, comprising: a receiving coil; a second shielding member positioned farther from the power transmitting device in the power transmission direction than the receiving coil, with the receiving coil positioned between the power transmitting device in the power transmission direction; and a receiving core positioned between the receiving coil and the second shielding member in the power transmission direction, wherein the second shielding member includes: a third member configured to overlap with the receiving core when viewed along the power transmission direction; and a fourth member positioned outside the receiving core in a direction intersecting the power transmission direction and extending from the third member in the power transmission direction and in a direction approaching the receiving core.

9. The power receiving device according to claim 8, wherein the second shielding member includes a second magnetic member.

10. The power receiving device according to claim 9, wherein the second magnetic member is provided at a portion of the third member that faces the power receiving coil in the power transmission direction.

11. A power receiving device as described in claim 9 or 10, wherein the second magnetic member is provided at a portion of the fourth member that faces the power receiving core in a direction intersecting the power transmission direction.

12. A power receiving device according to any one of claims 9 to 11, wherein the second magnetic member is provided on a portion of the fourth member that faces the power transmitting device in the power transmission direction.

13. The power receiving device according to any one of claims 9 to 12, wherein the second magnetic member has a thickness smaller than that of the power receiving core.

14. A power receiving device according to any one of claims 8 to 13, further comprising a first auxiliary power receiving coil located between the second shield member and the power receiving core in the power transmission direction.

15. A power transmitting device comprising: a power receiving device capable of receiving power wirelessly transmitted from the power transmitting device along a power transmission direction, wherein the power transmitting device comprises: a power transmitting coil; a first shielding member located farther from the power receiving device in the power transmission direction than the power transmitting coil, and with the power transmitting coil positioned between the power receiving device in the power transmission direction; and a power transmitting core located between the power transmitting coil and the first shielding member in the power transmission direction, wherein the first shielding member comprises: a first member configured to overlap with the power transmitting core when viewed along the power transmission direction; and a second member located outside the power transmitting core in a direction intersecting the power transmission direction and extending from the first member in the power transmission direction and in a direction approaching the power transmitting core, wherein the power receiving device comprises: a power receiving coil; and a second shielding member located farther from the power transmitting device in the power transmission direction than the power receiving coil, and with the power receiving coil positioned between the power transmitting device in the power transmission direction. a receiving core located between the receiving coil and the second shield member in the power transmission direction, wherein the second shield member includes: a third member configured to overlap the receiving core when viewed along the power transmission direction; and a fourth member located outside the receiving core in a direction intersecting the power transmission direction and extending from the third member in the power transmission direction and in a direction approaching the receiving core.

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