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Underground trolley vehicle with brushless D.C. Motor

  • US 5,221,880 A
  • Filed: 10/15/1992
  • Issued: 06/22/1993
  • Est. Priority Date: 10/15/1992
  • Status: Expired due to Fees
First Claim
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1. A mining vehicle for use on a high voltage, D.C. trolley system of the type having an overhead high voltage conductor and a pair of parallel rails at ground potential, said mining vehicle comprising:

  • a vehicle frame;

    a plurality of flanged wheels positioned under said frame and connected thereto so as to support the weight of said vehicle, said wheels adapted to ride along the parallel rails of the trolley system, said vehicle frame carrying the following;

    a brushless D.C. motor having a rotor and a stator, said rotor carrying means for generating a field flux and said stator having a plurality of winding portions each portion capable of generating magnetic flux;

    means for mechanically coupling the rotary motion of said rotor to said plurality of wheels;

    a high voltage bus;

    connection means for contacting the high voltage conductor of the trolley system and for connecting the high voltage conductor to said high voltage bus;

    a switching network connected between said high voltage bus and said portions of said stator winding for delivering current to said portions of said stator winding;

    first transducer means for producing a first group of feedback signals representative of the position and speed of said rotor;

    second transducer means for producing a second group of feedback signal representative of the current delivered to said motor;

    means for producing an input signal representative of the desired speed of the vehicle;

    circuit means responsive to said input signal, said first group of feedback signals, and said second group of feedback signals, for producing control signals, said control signals for input to said switching network to control the application of current to said portions of said stator winding, said control signals causing the vehicle to travel at the desired speed and causing said motor to produce constant torque;

    capacitor means connected to said high voltage bus;

    first resistor means connected between said capacitor means and ground potential for discharging said capacitor means when said connection means loses contact with the high voltage conductor;

    second resistor means;

    detector means connected to said high voltage bus for connecting said bus to said second resistor means in the event of an over-voltage condition on said bus; and

    brakes for acting upon said flanged wheels for bringing said vehicle to a stop when desired.

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