Magnetic levitation transport system with non-contact inductive power supply and battery charging

• US 5,467,718 A
• Filed: 07/19/1993
• Issued: 11/21/1995
• Est. Priority Date: 07/20/1992
• Status: Expired due to Term

• Current Assignee: Daifuku Company Limited
• Original Assignee: Daifuku Company Limited
• Inventors: Shibata, Satoru, Murayama, Shigeto
• Primary Examiner(s): Oberleitner, Robert J.
• Assistant Examiner(s): MORANO IV, SAMUEL J
• Application Number:
  US08/093,791
• Time in Patent Office: 855 Days
• Field of Search: 104/281, 104/284, 104/286, 104/290, 104/293, 104/294, 191/10, 336/115, 336/117, 336/118, 336/129, 336/178, 323/347
• US Class Current: 104/284
• CPC Class Codes: B60L 13/10 Combination of electric propulsion and magnetic suspension or levitation
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 7/00304 Overcurrent protection

Abstract

A magnetic levitation transport system includes magnetic levitation vehicles each driven by a linear motor to run along a track. Induction lines extend through predetermined blocks of the running track to transmit a high frequency sine-wave current. Each vehicle includes electromagnets to attract levitating magnetic members extending along the running track, a pickup coil resonant with a frequency of the induction lines to generate an electromotive force, and a battery chargeable by the pickup coil. The electromagnets receive power from the pickup coil and/or the battery.

Claims

1. A magnetic levitation transport system comprising:

a magnetic levitation vehicle;

lines extending through predetermined blocks of a running track of said vehicle to transmit a high frequency sine-wave current therethrough;

wherein said vehicle is driven by a linear motor, and includes levitating magnetic force generating means to attract levitating magnetic members extending along said running track, a pickup coil resonant with a frequency of said lines to generate an electromotive force, a power receiving unit connecting said pickup coil to said levitating magnetic force generating means, and a battery connected to said power receiving unit,

with said power receiving unit receiving power from only said pickup coil and both charging said battery and supplying power to said levitating magnetic force generating means when said pickup coil is generating an electromotive force,

with said power receiving unit receiving power from only said battery and supplying power to said levitating magnetic force generating means when said pickup coil is generating no electromotive force.

2. A magnetic levitation transport system as defined in claim 1, wherein said lines are included in induction line units installed in said predetermined blocks and extending along inner walls of a guide rail.

3. A magnetic levitation transport system as defined in claim 2, wherein each of said induction line units includes, besides one of said lines, an elongated bracket extending along said guide rail, and pairs of upper and lower horizontal hangers supported by said bracket and arranged at predetermined intervals along said guide rail, and a pair of plastic ducts attached to distal ends of said hangers and extending along said guide rail.

4. A magnetic levitation transport system as defined in claim 3, wherein each of said lines is a strand wire formed of thin insulated wires and connected to one of said ducts, and covered with an insulator.

5. A magnetic levitation transport system as defined in claim 1, wherein said levitating magnetic force generating means comprises electromagnets, said battery supplying power to said electromagnets in portions of said running track destitute of said lines.

6. A magnetic levitation transport system as defined in claim 1, wherein said levitating magnetic force generating means includes electromagnets and permanent magnets.

7. A magnetic levitation transport system as defined in claim 6, wherein said electromagnets and said permanent magnets are arranged opposite said levitating magnetic members, respectively.

8. A magnetic levitation transport system as defined in claim 7, wherein each of said permanent magnets is formed cylindrical to surround one of said electromagnets.

9. A magnetic levitation transport system as defined in claim 1, wherein said levitating magnetic force generating means includes a plurality of electromagnets, and said levitating magnetic members are magnetized substantially at right angles to a running direction of said vehicle, said vehicle further including control means for controlling magnetic forces of said electromagnets, said control means being operable to control electrification of said electromagnets such that magnetic forces acting between said electromagnets and said levitating magnetic members are switched between attractive forces and repulsive forces.

10. A magnetic levitation transport system as defined in claim 9, wherein each of said electromagnets includes a gap sensor mounted centrally thereof to detect a gap between said vehicle and said guide rail.

11. A magnetic levitation transport system as defined in claim 1, further comprising levitated state detecting means for detecting a difference between a predetermined proper levitated state and an actual levitated state provided by a levitating force of said levitating magnetic force generating means, levitation control means operable in response to detection information received from said levitated state detecting means to control the levitating force of said levitating magnetic force generating means, thereby to maintain said predetermined proper levitated state, propelling force generating means for applying a forward or backward propelling force to said vehicle along a guide rail, and propelling force control means for controlling said propelling force generating means.

12. A magnetic levitation transport system as defined in claim 11, further comprising state value detecting means for detecting a state value variable with variations in weight of said vehicle, said propelling force control means being operable in response to detection information received from said state value detecting means to control said forward or backward propelling force.

13. A magnetic levitation transport system as defined in claim 12, wherein said levitated state detecting means is operable to detect a difference between a predetermined proper value and energy supplied to said levitating magnetic force generating means, and variations in a gap between said vehicle and said guide rail, said levitation control means is operable to control the levitating force of said levitating magnetic force generating means to bring said energy supplied to said levitating magnetic force generating means to said predetermined proper value in the absence of variations in said gap, and said state value detecting means is operable to detect said gap.

14. A magnetic levitation transport system as defined in claim 11, wherein said levitated state detecting means is operable to detect a difference between a predetermined proper gap and an actual gap between said vehicle and said guide rail, said levitation control means is operable to control the levitating force of said levitating magnetic force generating means to bring said actual gap to said proper gap, and said state value detecting means is operable to detect the levitating force of said levitating magnetic force generating means.

15. A magnetic levitation transport system as defined in claim 11, wherein said levitated state detecting means includes current detecting circuits and gap sensors, the levitating force of said levitating magnetic force generating means being controllable based on detection information from said gap sensors.

16. A magnetic levitation transport system comprising:

a magnetic levitation vehicle;

lines extending through predetermined blocks of a running track of said vehicle to transmit a high frequency sine-wave current therethrough;

a station installed on said lines;

a first communication means provided on said vehicle; and

a second communication means provided on said station;

wherein said vehicle is driven by a linear motor, and includes levitating magnetic force generating means to attract levitating magnetic members extending along said running track, a pickup coil resonant with a frequency of said lines to generate an electromotive force, a power receiving unit connecting said pickup coil to said levitating magnetic force generating means, and a battery connected to said power receiving unit;

with said power receiving unit receiving power from only said pickup coil and both charging said battery and supplying power to said levitating magnetic force generating means when said pickup coil is generating an electromotive force, and with said power receiving unit receiving power from only said battery and supplying power to said levitating magnetic force generating means when said pickup coil is generating no electromotive force; and

with said first communication means and said second communication means communicating information, by means of optical communication, regarding identification, movement and load conditions of said vehicle, and charge of said battery.