Power transmission device, power reception device and power transfer system

• US 9,917,478 B2
• Filed: 11/18/2011
• Issued: 03/13/2018
• Est. Priority Date: 11/18/2011
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Ichikawa, Shinji
• Primary Examiner(s): BARNIE, REXFORD N
• Assistant Examiner(s): Mourad, Rasem
• Application Number:
  US14/358,658
• Publication Number:
  US 20150001957A1
• Time in Patent Office: 2,307 Days
• CPC Class Codes: B60L 53/126 Methods for pairing a vehicle and a charging station, e.g. establishing a one-to-one relation between a wireless power transmitter and a wireless power receiver
• CPC Class Codes: H01F 27/363 made of electrically conductive material
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

A power transmission device includes a power transmission unit transmitting electric power in a contactless manner to a power reception unit provided outside; and a power transmission-side shield formed in a hollow shape and provided so as to surround the power transmission unit. An electromagnetic wave can pass through a region on a side opposite to a region where the power reception unit is located across the power transmission-side shield. The power transmission-side shield is provided with a shield member on a side opposite to the power transmission unit across the power transmission-side shield.

Claims

1. A power transmission device comprising:

a power transmission unit transmitting electric power in a contactless manner to a power reception unit provided outside;

a power transmission-side shield formed in a hollow shape and provided so as to surround said power transmission unit, the power transmission-side shield defining a first opening on a first side of the power transmission-side shield facing the power reception unit and a second opening on a second side of the power transmission-side shield opposite the first side,

a cover disposed on the first side of the power transmission-side shield to cover the first opening, the cover being formed of a material without an electromagnetic wave screening effect to permit an electromagnetic wave generated by the power transmission unit to pass through the first opening and the cover, and

a shield member extending outwardly in a radial direction of the hollow shape of the power transmission-side shield,

the power transmission device being configured to permit an electromagnetic wave generated by the power transmission unit to pass through the second opening and

said power transmission-side shield being provided on an outer circumferential surface side thereof with the shield member.

2. The power transmission device according to claim 1, wherein said shield member is electrically connected to said power transmission-side shield.

3. The power transmission device according to claim 2, wherein said shield member is electrically connected to an end of said power transmission-side shield on the second side of the power transmission-side shield.

4. The power transmission device according to claim 1, wherein a difference between a natural frequency of said power transmission unit and a natural frequency of said power reception unit is equal to or less than 10% of the natural frequency of said power reception unit.

5. The power transmission device according to claim 1, wherein a coupling coefficient between said power reception unit and said power transmission unit is equal to or less than 0.1.

6. The power transmission device according to claim 1, wherein said power transmission unit transmits electric power to said power reception unit through at least one of a magnetic field formed between said power reception unit and said power transmission unit and oscillating at a specific frequency, and an electric field formed between said power reception unit and said power transmission unit and oscillating at a specific frequency.

7. A power transfer system comprising:

a power transmission device including a power transmission unit; and

a power reception device including a power reception unit receiving electric power from said power transmission unit in a contactless manner,

said power transmission device including

a power transmission-side shield formed in a hollow shape and provided so as to surround said power transmission unit the power transmission-side shield defining a first opening on a first side of the power transmission-side shield facing the power reception unit and a second opening on a second side of the power transmission-side shield opposite the first side, and

a cover disposed on the first side of the power transmission-side shield to cover the first opening, the cover being formed of a material without an electromagnetic wave screening effect to permit an electromagnetic wave generated by the power transmission unit to pass through the first opening and the cover, and

a shield member extending outwardly in a radial direction of the hollow shape of the power transmission-side shield and

said power transmission device being configured such that

an electromagnetic wave generated by the power transmission unit is permitted to pass through the second opening, and

said power transmission-side shield is provided on an outer circumferential surface side thereof with the shield member.

8. The power transfer system according to claim 7, wherein said shield member is electrically connected to said power transmission-side shield.

9. The power transfer system according to claim 8, wherein said shield member is electrically connected to an end of said power transmission-side shield on the second side of the power transmission-side shield.

10. A power reception device comprising:

a power reception unit receiving electric power in a contactless manner from a power transmission unit provided outside;

a power reception-side shield formed in a hollow shape and provided so as to surround said power reception unit, the power reception-side shield defining a first opening on a first side of the power reception-side shield facing the power transmission unit and a second opening on a second side of the power reception-side shield opposite the first side,

a cover disposed on the first side of the power reception-side shield to cover the first opening the cover being formed of a material without an electromagnetic wave screening effect to permit an electromagnetic wave generated by the power transmission unit to pass through the first opening and the cover, and

a shield member extending outwardly in a radial direction of the hollow shape of the power reception-side shield,

the power reception device being configured to permit an electromagnetic wave generated by the power transmission unit to pass through the second opening, and

said power reception-side shield being provided on an outer circumferential surface side thereof with the shield member.

11. The power reception device according to claim 10, wherein said shield member is electrically connected to said power reception-side shield.

12. The power reception device according to claim 11, wherein said shield member is electrically connected to an end of said power reception-side shield on the second side of the power reception-side shield.

13. The power reception device according to claim 10, wherein a difference between a natural frequency of said power transmission unit and a natural frequency of said power reception unit is equal to or less than 10% of the natural frequency of said power reception unit.

14. The power reception device according to claim 10, wherein a coupling coefficient between said power reception unit and said power transmission unit is equal to or less than 0.1.

15. The power reception device according to claim 10, wherein said power reception unit receives electric power from said power transmission unit through at least one of a magnetic field formed between said power reception unit and said power transmission unit and oscillating at a specific frequency, and an electric field formed between said power reception unit and said power transmission unit and oscillating at a specific frequency.

16. A power transfer system comprising:

a power transmission device including a power transmission unit; and

a power reception device including a power reception unit receiving electric power from said power transmission unit in a contactless manner,

said power reception device including

a power reception-side shield formed in a hollow shape and provided so as to surround said power reception unit, the power reception-side shield defining a first opening on a first side of the power reception-side shield facing the power transmission unit and a second opening on a second side of the power reception-side shield opposite the first side,

a cover disposed on the first side of the power reception-side shield to cover the first opening the cover being formed of a material without an electromagnetic wave screening effect to permit an electromagnetic wave generated by the power transmission unit to pass through the first opening and the cover, and

a shield member extending outwardly in a radial direction of the hollow shape of the power reception-side shield, and

said power reception device being configured such that

an electromagnetic wave is permitted to pass through the second opening, and

said power reception-side shield is provided on an outer circumferential surface side thereof with the shield member.

17. The power transfer system according to claim 16, wherein said shield member is electrically connected to said power reception-side shield.

18. The power transfer system according to claim 17, wherein said shield member is electrically connected to an end of said power reception-side shield on the second side of the power reception-side shield.