Planer drive

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In mining, a planer drive is a mechanical device that moves the coal plow .

construction

Chain star

The drive of the coal plow is divided into main drive and auxiliary drive. The main drive is the drive station, which is located in the conveying direction, the auxiliary drive is located at the other end of the strut . Each drive station consists of the motor, the clutch, the gearbox and the chain star . Each drive station is bolted to the extraction system via a planer drive frame. A motor brake is used to brake the motor. The drive stations can be moved with hydraulic rear devices.

Engines

Either air motors or electric motors were used as drive motors in the past . Each drive was equipped with either one or two motors. There were different combinations of both engines. There were drives with only air motors or drives with one air motor and one electric motor each. The engines had outputs of up to 40 kilowatts. Today's drives are only driven by three-phase squirrel cage motors. These motors have an operating voltage of 500 or 1000 volts . The direction of rotation of the motors can be changed using a reversing contactor circuit. The motors have an average output of 160 kilowatts, there are also drives in which motors with 300 kilowatts are used. Pole-changing motors are used in order to be able to drive the planer at different speeds.

Couplings

In the earlier planer drives with an electric motor, multi-plate clutches were used to transmit the torque to the drive shaft. These clutches were operated pneumatically. The lamellae were pressed against each other via an electromagnetically controlled compressed air valve. A minimum pressure of 3.3 bar was required. Flexible pin couplings were used for drives with compressed air motors. Today's drives are equipped with torsionally flexible or hydrodynamic couplings , depending on the motor used . Only torsionally flexible mechanical couplings can be used for drives with pole-changing motors. Hydrodynamic couplings can also be used for drives with three-phase motors without pole changing. Each of these couplings is equipped with an overload protection. This overload protection responds to inadmissibly high loads and is intended to protect the plow chain against chain breakage. In the past, shear pin couplings were used as overload protection. The shear bolt broke under a load of 20 tons. According to more recent findings, shear pin couplings have a detrimental effect on the service life of the plow chain. The abrupt, sudden interruptions in the power flow also have a negative effect on the engine and the transmission. For this reason, safety clutches are used in newer drives that slip in the event of overload.

transmission

Helical gears or bevel helical gears are used as gears . Planetary superposition gears are used in newer drives . These gearboxes have two input shafts. The motor is flanged to one input shaft and hydrostatic units are attached to the other input shaft. These units have the same output as the electric motor and serve as a torque support. A chain star with floating bearing is attached to the output shaft. Gearboxes equipped in this way, in combination with an electrohydraulic clutch, enable the load to be balanced between the main and auxiliary drives.

Power transmission to the plow chain

The chain star , also known as the chain wheel , is used to drive the plow chain . A positive drive of the chain is possible through the chain star. To prevent the same chain links and teeth from always meshing, chain stars have an uneven number of teeth. The chain has an even number of chain links. So that the chain star does not wear out prematurely due to dry running , the plow chain must be moistened with oil . A chain lubrication device can be attached to the planer drive for this purpose.

Individual evidence

  1. ^ A b c d Walter Bischoff , Heinz Bramann, Westfälische Berggewerkschaftskasse Bochum: The small mining encyclopedia . 7th edition, Verlag Glückauf GmbH, Essen 1988, ISBN 3-7739-0501-7 .
  2. a b c d Heinz M. Hiersig (Ed.): VDI-Lexikon Maschinenbau . VDI-Verlag GmbH, Düsseldorf 1995, ISBN 9783540621331 , p. 614.
  3. ^ A b c d e Heinz Kundel: coal production. 6th edition, Verlag Glückauf GmbH, Essen, 1983, ISBN 3-7739-0389-8 .
  4. ^ A b c Carl Hellmut Fritzsche: Textbook of mining science. First volume, 10th edition, Springer Verlag, Berlin / Göttingen / Heidelberg 1961.
  5. Katrin Berger: Continuous conveyor . A terminological study in German and French. Master's thesis at the Institute for Applied Linguistics and Translatology at the University of Leipzig, Leipzig 2014, p. 42.
  6. Horst Roschlau, Wolfram Heintze: Bergmaschinentechnik . VEB Deutscher Verlag für Grundstofftindustrie, Leipzig 1977, p. 37.
  7. ^ Thiele GmbH & Co KG (ed.): Operating instructions for mining . Conveyor chains, chain gauges, plow chains. Iserlohn, pp. 20-23.