Rubber-tire gantry crane with shore power

• US 20090127048A1
• Filed: 11/20/2007
• Published: 05/21/2009
• Est. Priority Date: 11/20/2007
• Status: Active Grant

• Current Assignee: Paceco Corporation (Tsuneishi Holdings Company Limited)
• Original Assignee: Paceco Corporation (Tsuneishi Holdings Company Limited)
• Inventors: Ichimura, Kinya
• Granted Patent: US 8,061,495 B2
• Time in Patent Office: Days
• US Class Current: 191/33.R
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 2210/20 AC to AC converters
• CPC Class Codes: B60L 5/005 without mechanical contact between the collector and the power supply line
• CPC Class Codes: B60L 9/16 using ac induction motors
• CPC Class Codes: B60M 1/34 in slotted conduits
• CPC Class Codes: B66C 13/12 Arrangements of means for transmitting pneumatic, hydraulic, or electric power to movable parts of devices
• CPC Class Codes: B66C 19/007 for containers
• CPC Class Codes: H02G 11/02 using take-up reel or drum
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

An apparatus for coupling power from shore power to a rubber tire gantry (RTG) crane comprises a power junction trolley and optionally an RTG crane. The power junction trolley receives power through a high voltage cable or alternatively through an inductive power coupling and alternatively outputs a low AC or a low DC voltage through a flexible power cable for connection to an RTG crane. A guiding apparatus directs the power junction trolley along a selected path so as to reduce a control accuracy requirement for the RTG crane. The RTG crane may move from a selected path to another selected path without interrupting a high voltage connection. The power junction trolley optionally determines its position relative to a selected path comprising a guide rail in some embodiments and a guide wire in others. Embodiments of the power junction trolley are alternately self-propelled or towed by the RTG crane.

Claims

1. An apparatus for coupling power from a high voltage electrical network to a low voltage power input on a mobile crane, comprising:

a trolley;

a guiding apparatus attached to said trolley;

a transformer attached to said trolley, wherein said transformer comprises a high voltage input and a low voltage output and said low voltage output has a value selected for powering the crane; and

a power input coupler adapted to receive power from the high voltage electrical network, said power input coupler connected to said high voltage input of said transformer.

2. The apparatus of claim 1, wherein said power input coupler is adapted to receive power inductively.

3. The apparatus of claim 1, wherein said power input coupler is adapted to connect to a high voltage cable.

4. The apparatus of claim 1, further comprising a rubber tire gantry crane having a low voltage input, wherein said low voltage input of said rubber tire gantry crane is connected to said low voltage output of said trolley.

5. The apparatus of claim 4, further comprising:

a flexible signal cable connecting said trolley to said rubber tire gantry crane;

a position signal representative of a position of said trolley, wherein said position signal is carried by said flexible signal cable; and

a position of said rubber tire gantry crane, wherein said rubber tire gantry crane is adapted to modify said position of said rubber tire gantry crane in response to said position signal.

6. The apparatus of claim 5, further comprising a power conversion circuit having an alternating current (AC) input and a direct current (DC) output, wherein said power conversion circuit is inserted in series between said low voltage output of said transformer and said low voltage input, and said rubber tire gantry crane is adapted to operate from a DC current.

7. The apparatus of claim 3, further comprising:

a cable reel rotationally coupled to said trolley;

an electrical connection between said power input coupler and said cable reel; and

an electrical connection between said cable reel and said high voltage input of said transformer.

8. The apparatus of claim 7, further comprising:

a selected path for said trolley; and

a guide rail located a selected separation distance from said selected path.

9. The apparatus of claim 8, further comprising:

a first guide rail side;

a second guide rail side;

said guiding apparatus further comprising a guide roller assembly attached to said power junction trolley; and

said guide roller assembly further comprising;

a guide roller assembly bracket;

a first guide roller axle attached to said guide roller assembly bracket;

a second guide roller axle attached to said guide roller assembly bracket;

a first guide roller rotatably assembled to said first guide roller axle, wherein said first guide roller rolls along said first guide rail side; and

a second guide roller rotatably assembled to said second guide roller axle, wherein said second guide roller rolls along said second guide rail side.

10. The apparatus of claim 8, further comprising:

a first position sensor attached to said trolley;

a first position sensor output signal representing a first distance of said trolley from said guide rail; and

a position controller attached to said trolley, wherein said position controller has a first input connected to said first position sensor output signal and a first output value representing said first distance from said guide rail.

11. The apparatus of claim 10, further comprising:

said trolley further comprising four wheels;

said position controller having a first control output;

an electric motor controller having a control input connected to said position controller first control output and a motor control output; and

an electric motor having a rate of rotation wherein said electric motor is cooperatively connected to at least one of said wheel on said trolley and said rate of rotation of said electric motor is controlled by said electric motor controller motor control output.

12. The apparatus of claim 11, further comprising:

a second position sensor attached to said trolley;

a second position sensor output signal representing a second distance of said trolley from said guide rail; and

said position controller having a second input connected to said second position sensor output signal and a second output value representing said second distance from said guide rail.

13. The apparatus of claim 12, further comprising:

said trolley having a direction of travel;

said position controller having a second control output;

a second electric motor controller having a control input connected to said position controller second control output and a motor control output; and

a second electric motor having a rate of rotation cooperatively connected to at least one of said wheel on said trolley, wherein said rate of rotation of said second electric motor is controlled by said second electric motor controller motor control output.

14. The apparatus of claim 13, further comprising:

a selected direction of travel of said trolley; and

a deviation angle output signal from said position controller, wherein said deviation angle output signal represents an angle between said direction of travel of said trolley and said selected direction of travel of said trolley.

15. The apparatus of claim 14, wherein said position controller controls said first electric motor and said second electric motor to change said direction of travel of said trolley in response to a value of said deviation angle output signal.

16. A method for connecting shore power to a rubber tire gantry crane, comprising:

connecting a shore power cable to a high voltage power input on a power junction trolley; and

connecting a flexible power cable from a low voltage power output on the power junction trolley to a low voltage power input on the rubber tire gantry crane.

17. The method of claim 16, further comprising:

disconnecting the rubber tire gantry crane from the flexible power cable; and

connecting the rubber tire gantry crane to a second flexible power cable from a second power junction trolley, without disconnecting a shore power connection.

18. The method of claim 16, further comprising:

selecting a position for the shore power cable;

selecting a path for the power junction trolley relative to the position for the shore power cable; and

moving the power junction trolley along the selected path in response to a corresponding movement of the rubber tire gantry crane.

19. The method of claim 18, further comprising:

communicating a position of the shore power trolley to the rubber tire gantry crane; and

adapting a position of the rubber tire gantry crane in response to the position of the power junction trolley.

20. A rubber tire gantry crane powered from an external electrical power source, comprising:

a power junction trolley having a high voltage input terminal and a low voltage output terminal;

a low voltage input terminal on the rubber tire gantry crane; and

a flexible power connection from said low voltage output terminal on said power junction trolley to said low voltage input terminal on the rubber tire gantry crane.

21. The rubber tire gantry crane of claim 20, wherein disconnecting the rubber tire gantry crane from the external power source does not interrupt a high voltage connection.

22. The rubber tire gantry crane of claim 21, wherein said power junction trolley further comprises a transformer having a high voltage input connected to said high voltage input terminal on said power junction trolley and a low voltage output connected to said low voltage output terminal on said power junction trolley.

23. The rubber tire gantry crane of claim 22, further comprising:

a selected path for said power junction trolley;

a guide rail having a position relative to said selected path for said power junction trolley; and

a guide roller assembly attached to said power junction trolley, wherein said guide roller assembly further comprises;

a guide roller assembly bracket;

a first guide roller axle attached to said guide roller assembly bracket;

a second guide roller axle attached to said guide roller assembly bracket;

a first guide roller rotatably assembled to said first guide roller axle; and

a second guide roller rotatably assembled to said second guide roller axle,

wherein said first and second guide rollers roll along said guide rail, thereby causing said power junction trolley to follow said selected path for said power junction trolley.

24. The rubber tire gantry crane of claim 22, further comprising a power conversion circuit having an alternating current (AC) input and a direct current (DC) output, wherein said power conversion circuit is inserted in series between said low voltage output of said transformer and said low voltage input, and said rubber tire gantry crane is adapted to operate from a DC current.

25. The rubber tire gantry crane of claim 22, wherein said power junction trolley further comprises:

a first position sensor having an output signal representing a first position of said power junction trolley;

a second position sensor having an output signal representing a second position of said power junction trolley;

a motor having a rate of rotation;

a motor controller having a control input and an output connected to said motor;

a position controller having a control output connected to said control input on said motor controller, a first input connected to said first position sensor output, and a second input connected to said second position sensor output;

a selected direction of travel; and

a measured direction of travel related to said first and second position sensor output signals,

wherein said position controller changes said rate of motor rotation in response to a difference between said measured direction of travel and said selected direction of travel.