Device for contactless power supply to moving body

• US 5,709,291 A
• Filed: 05/28/1996
• Issued: 01/20/1998
• Est. Priority Date: 05/22/1992
• Status: Expired due to Term

• Current Assignee: Daifuku Company Limited
• Original Assignee: Daifuku Company Limited
• Inventors: Iwama, Michio, Imanaka, Tomomi, Nishino, Shuzo
• Primary Examiner(s): Le, Mark T.
• Application Number:
  US08/335,867
• Time in Patent Office: 602 Days
• Field of Search: 191/2, 191/3, 191/4, 191/5, 191/6, 191/7, 191/10, 191/14-21, 246/187 R, 246/187 A, 246/187 B, 320/2, 320/21
• US Class Current: 191/10
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 5/005 without mechanical contact between the collector and the power supply line
• CPC Class Codes: B60M 1/34 in slotted conduits

Abstract

A device for contactlessly supplying power to a moving body (2) such as a pallet being transported in a predetermined transport passage and carrying a device to be supplied with power while supplying power to the last-mentioned device. An induction wire (14) is laid along the transport passage (1) and a high frequency sine wave current is passed through the induction wire (14). The moving body (2) is provided with a coil (16) in which an electromotive force is produced by the action of the magnetic flux produced by the induction wire (14), a capacitor (31) cooperating with the coil (16) to form a resonance circuit adapted to resonate at the frequency of the current flowing through the induction wire (14), and a power switch circuit connected to the resonance circuit and supply power to the device to be supplied with power.

Claims

1. A transport system comprising:

a magnetic field shielding member having a C-shaped cross-section, which has a concave portion formed therein and is disposed along a transport passage guiding a moving body, said moving body being arranged in a non-guiding relationship with said shielding member;

an induction wire laid out in said concave portion of the magnetic field shielding member and a power source supplying said induction wire with a high frequency sine wave current;

a coil disposed in said moving body and caused to produce an electromotive force by a magnetic flux of said induction wire, said coil extending into said concave portion;

a capacitor disposed in said moving body and cooperating with said coil to form a resonance circuit which resonates at the frequency of a current flowing through said induction wire; and

a power source circuit provided in said moving body and connected to said resonance circuit so as to supply power to a power receiving device provided on said moving body.

2. A transport system as set forth in claim 1, wherein the induction wire is in the form of a loop with its initial and terminal ends connected to a power source and is so arranged in the concave portion of the magnetic field shielding member as to be in the form of a pair of wires differing from each other in the direction of current flow, and the coil is positioned substantially in the middle between said pair of wires in said concave portion.

3. A transport system as set forth in claim 1, wherein a switch and the power source circuit are connected in parallel with the coil of the moving body.

4. A transport system as set forth in claim 1, wherein the induction wire and the coil are each in the form of a twisted wire composed of thin insulated strands.

5. A transport system as set forth in claim 1 or 2 wherein the moving body is a pallet, and the magnetic field shielding member is suspended toward said pallet with its concave portion directed downward and the coil is positioned on the upper surface of said pallet opposed to said magnetic field shielding member.

6. A transport system as set forth in claim 1 or 2, wherein the moving body is a pallet, and the magnetic field shielding member is suspended toward said pallet with its concave portion directed upward and the coil is positioned on the lower surface of said pallet opposed to said magnetic field shielding member.

7. A transport system as set forth in claim 1 or 2, wherein the magnetic field shielding member is positioned toward the moving body with its concave portion directed horizontally, and the coil is positioned on a lateral surface of said moving body opposed to said magnetic field shielding member.

8. A transport system as set forth in claim 1, wherein the moving body is a carriage and the power-receiving device is a lifter mounted on said carriage, said lifter being capable of lifting and lowering while supporting the body of a vehicle transported by said carriage.

9. A transport system as set forth in claim 1, further comprising a self-propelled traveling body as the moving body, a battery mounted on said traveling body as the power-receiving device, and a charging circuit to said battery as the power source circuit, wherein

the traveling body is provided with a motor for traveling itself by employing the battery as its drive power source;

a single or a plurality of work stations each having a work stand are disposed on the transport passage of the traveling body;

the induction wire is laid out along a lateral surface of each said work stand; and

the coil is positioned to a lateral surface of said work stand opposed to said lateral surface laid out with said induction wire.

10. A transport system as set forth in claim 9, wherein the traveling body travels at a lower speed in each said work station than outside each said work station.