US3633081A - Apparatus for controlling and regulating a cutter hoist - Google Patents

Apparatus for controlling and regulating a cutter hoist Download PDF

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Publication number
US3633081A
US3633081A US47529A US3633081DA US3633081A US 3633081 A US3633081 A US 3633081A US 47529 A US47529 A US 47529A US 3633081D A US3633081D A US 3633081DA US 3633081 A US3633081 A US 3633081A
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United States
Prior art keywords
drive motor
motor
current
advancing
speed
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Expired - Lifetime
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US47529A
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English (en)
Inventor
Karl Heinz Weber
Horst Engelhardt
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Gebr Eickhoff Maschinenfabrik u Eisengiesserei GmbH
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Gebr Eickhoff Maschinenfabrik u Eisengiesserei GmbH
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Priority claimed from DE19691931357 external-priority patent/DE1931357C/de
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    • EFIXED CONSTRUCTIONS
    • E21EARTH OR ROCK DRILLING; MINING
    • E21CMINING OR QUARRYING
    • E21C35/00Details of, or accessories for, machines for slitting or completely freeing the mineral from the seam, not provided for in groups E21C25/00 - E21C33/00, E21C37/00 or E21C39/00
    • E21C35/24Remote control specially adapted for machines for slitting or completely freeing the mineral
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02PCONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P29/00Arrangements for regulating or controlling electric motors, appropriate for both AC and DC motors
    • H02P29/40Regulating or controlling the amount of current drawn or delivered by the motor for controlling the mechanical load

Definitions

  • Att0meyBrown, Murray, Flick & Peckham ABSTRACT Motor control system for a mining machine of the type in which a cutting element is driven by a first electrical motor and the mining machine is advanced into a coal face by a second motor.
  • the system is characterized in that the torque and speed of the second motor are reduced both when the cutter element drive motor is idling as well as when the cutter motor is overloaded.
  • the arrangement is such that as the cutting element approaches the coal seam and is idling, the speed of the advancing drive motor is relatively low; when the cutter enters the coal face and the current to the cutter drive motor increases, the speed of the advancing drive motor is also increased; and when the cutter element drive motor is overloaded, the advancing drive motor is reversed to withdraw the cutting element from the coal face and thereafter again advances the cutting element into the coal face in a pulsing or reciprocating motion.
  • the present invention is particularly adapted for use in controlling the drive motors for a longwall mining machine.
  • a cutting machine is employed that cuts along the longwall face of the coal seam while moving longitudinally along the longwall face on a guideway or track placed therealong.
  • a suitable cutting machine for performing this operation usually consists of a machine body movable along the guideway, and one or more support arms pivotally attached to the body and carrying rotary cutting tools.
  • a longwall mining machine of this type is usually advanced by means of a winch arrangement comprising a chain wheel which is in engagement with a chain looped about a guide chain wheel and anchored at its opposite ends to the ends of the longwall face.
  • a drive motor can be referred to as an advancing drive motor; while the motor or motors which drive the cutting element can be referred to as a cutter drive motor.
  • the load on the cutter drive motor will be a function not only of the hardness of the coal being mined, but also the speed of advance of the cutter into the coal face as determined by the speed and torque of the advancing drive motor.
  • the operation of the two motors must be correlated in order to prevent overloading of the cutter drive motor.
  • the cutting element when it is not engaging a coal face, it should be running at idling speed. As the cutting element approached and engaged the coal face at the idling speed its speed and torque should be increased as well as the speed of advance of the mining machine.
  • the operation of the advancing drive motor must be correlated with the cutter drive motor in order that when the cutting element engages a coal face, the speed of the advancing motor will be increased.
  • the advancing drive motor should be reversed to withdraw the cutting element from the coal seam, followed by advancement of the cutting element back into the coal seam.
  • a motor control system for a mining machine wherein the operation of a cutter drive motor and a mining-machine-advancing motor are correlated such that sudden load increases on the cutter element motor and advancing drive motor, which can occur with an abrupt entering of the cutting element into the working face, are avoided to a great extent. Moreover, the load variations which occur during normal cutting operations and which are caused by the variable hardness of the coal being mined are constantly restored to a manually set nominal value.
  • a motor control servo loop for a direct current advancing drive motor including the usual voltage regulator and current limiter, the output of which drives thyristor firing circuits for a dual-bridge thyristor power supply which supplies driving potential to the advancing drive motor.
  • the current through both the cutter drive motor as well as the advancing drive motor is sensed; and should the current through either motor exceed a predetermined value, indicating an excessive torque on the motor, the current limiter reduces the speed of the advancing motor and, hence, the load on both motors.
  • the control for the advancing motor is such that a nominal predetermined advancing speed is established when no load is on the cutter drive motor.
  • a threshold detector which causes the motor control system to increase the speed of the advancing motor.
  • the cutting element may incur certain obstacles such as props, cross timbers and the like, which act to overload either or both the cutter drive motor and the advancing motor.
  • Such an overloading occurs suddenly and persists for a given time period as contrasted, for example, with a momentary overload which may occur due to various factors.
  • a second current-limiting circuit in the motor control system which, in response to an excessive overload condition for a predetermined period of time, will cause the current to the armature of the direct current advancing motor to become reversed, whereby the cutting element will be withdrawn from the coal face.
  • the speed of the advancing motor is reversed, and the cutter element again caused to approach the coal face.
  • the system of the invention additionally includes over temperature protection systems effective on the current limiter of the main control loop for the advancing motor to reduce its speed.
  • the speed of the advancing motor is monitored; and when it exceeds a maximum permissible value, the firing angle of thyristors supplying power to the field winding of the drive motor is reduced until the speed of the motor is again brought back to a permissible value.
  • FIG. 1 is a schematic illustration of one type of mining machine with which the present invention may be used.
  • FIG. 2 comprises a schematic circuit diagram of the motor control system of the invention.
  • the arrow A denotes the direction in which a mining machine B, movable on tracks or guideways C, advances along the face D of a mineral seam which, in the usual case, is a coal seam.
  • the mining machine B is provided with a rotary cutting element E that cuts and removes the coal and exposes a new coal face F when the mining machine B advances along the coal face D that has been exposed by a preceding cut.
  • the mining machine is driven by means of an advancing direct current drive motor 3 connected to a winch-type chain wheel H around which a chain J passes.
  • the chain J is secured at one end of the longwall coal face D as at K; and its other end is secured at the opposite end of the longwall coal face as at L.
  • the chain J extends from point K, around the driving chain wheel H, thence around a guide wheel M to point L where it is secured.
  • the rotary cutting element E is driven by means of a three-phase alternating-current motor 2.
  • the cutting element E is usually carried on a pivoted arm such that it can be raised or lowered; and in many cases the mining machine will incorporate two cutter elements on pivoted arms, one at the front and one at the back, such that the forward cutting element can work the floor of the seam while the rear element works the upper seam portion. In that case, both cutter elements are driven by the single motor 2.
  • the motor 3 will cause the mining machine to advance to the right along the direction of arrow A; while the cutting element E rotates and removes an entire layer of the longwall face.
  • the cutting element E is pivotally mounted such that it can be raised or lowered; and, thus, two or more excursions of the mining machine can be made to remove the entire height of a coal face, depending upon its height. After the entire face is removed, the tracks C are then moved upwardly as viewed in FIG. 1, whereupon the process is repeated to remove a succeeding layer of coal.
  • the control circuitry for the motors 2 and 3 is shown in FIG. 2 and includes the three conductors or phases R, S, and T of a three-phase power supply, not shown.
  • the conductors R, S and T are connected through master switch 1 to the threephase altemating-current motor 2 which is designed to rotate at a constant rate of speed. This speed can be varied by external control circuitry, not shown, however during a mining operation it will ordinarily rotate at one selected speed.
  • the direct current advancing motor 3 is powered by means of a pair of balanced thyristor bridges 19 and 19 adapted to supply current through the armature of motor 3 in either direction and, hence, cause its direction of rotation to reverse.
  • the junctions of the diodes in the two thyristor bridges 19 and 19 are connected to the same three-phase power conductors R, S and T as is the altemating-current cutter drive motor 2.
  • the motor control servo loop for the motor 3 includes the usual voltage regulator 14 connected at its output to a current limiter 15.
  • the current limiter 15 is connected through switch 17 to two thyristor firing circuits l8 and 18 for the dual bridge thyristor power supplies l9 and 19', respectively.
  • Connected to the shaft of motor 3 is a tachometer generator 12 connected through lead 13 back to a summation point 11 where it is compared with the output of a voltage reference controller 10.
  • the voltage reference controller 10 in turn, generates a reference voltage which is compared at summation point 11 with the feedback voltage from tachometer generator 12 to produce an error signal for the voltage regulator 14.
  • One of the leads connected to the altemating-current cutter drive motor 2 is provided with a current transformer 5 con nected through rectifier 5' and summation point 31 to lead 7 which, in turn, is connected to an OR-circuit 9.
  • one of the leads connected to the two thyristor units 19 and 19' is provided with a current transformer 6 connected through rectifier 6' and lead 8 to the OR-circuit 9.
  • a third input to the OR-circuit 9 is connected to the output of voltage reference controller 10.
  • the voltage reference controller 10 is provided with a switch, not shown, which initially establishes the rotating speed of the motor 3 when the motor 2 is idling and the cutter elementE is not loaded. Under these circumstances, the mining machine will advance to the right as shown in FIG. 1, for example, until the cutting element E engages the coal face; at which time the current through the motor 2 increases abruptly. This increase in current, in turn, is sensed by a threshold detector 22 which actuates a servomotor control 24 to cause a servomotor 21 to move the moveable wiper on a potentiometer 20 to the left as viewed in FIG. 2, thereby increasing the output of the voltage reference controller 10 and causing a corresponding increase in the speed of advancing motor 3.
  • the thyristor units 19 and 19' are provided with temperature sensing devices 25 which may, for example, comprise solid-state thyristors or other similar devices capable of producing an output signal proportional to temperature.
  • a similar temperature sensing device 25 is provided for the advancing drive motor 3.
  • the temperature sensing elements 25 are connected through leads 26, 27 and 28, respectively, to an OR-circuit 29, the output of the OR-circuit 29 being connected to the current limiter 15. In this manner, should the temperature of the thyristors in units 19 and 19', or the temperature of motor 3 exceed a predetermined value, the current limiter 15 will be actuated to again reduce the speed of the motor and prevent damage thereto because of overheating.
  • the cutter drive motor 2 is also provided with a temperature sensing element 25 which is connected, via lead 30, to the summation point 31.
  • a signal produced by the temperaturesensing device 25 is superimposed on the current signal derived from current transformer 5 on lead 7, thereby acting, through OR-circuit 9 to cause the current limiter 15 to reduce the speed of the motor 3 and, hence, reduce the load on motor 2 until the excessive temperature condition is eliminated.
  • the load current of the advancing motor 3 will normally not reach the nominal value which is preset manually. This is due to the fact that this nominal value is set very high, when the cutter drive motor 2 is switched ON, in order to utilize the capacity of the mining machine fully.
  • a current limiter circuit 32 actuates the switch 17 to interrupt the thyristor firing circuit 18, firing the thyristors in group 19 for example, and causes thyristor firing circuit 18' to fire the thyristors in group 19' whereby the direction of current flow through the motor 3 is reversed, as is its direction of rotation.
  • the switchover from one thyristor firing circuit to the other occurs in a period of about 20 milliseconds; however it is important that the switchover occur when the applied waveform crosses the zero axis. Accordingly, the voltage across the motor armature, appearing across resistors 34, is applied via lead 35 to the switch 17 such that the switchover from one thyristor firing circuit to the other occurs exactly at the zero crossing of the applied waveform.
  • the motor 3 will again reverse and the cutter element will advance toward the coal face.
  • the output of voltage reference controller dictated a relatively high rate of speed of the motor 3; whereas it is desired to reenter the coal face slowly.
  • a signal from switch 17 on lead 36 which occurs when the switch 17 is actuated by holding circuit 33, is applied via lead 37 and through R-C network 38 to the servomotor control 24 which causes the servomotor 21 to rotate potentiometer such that the output of the voltage reference controller again dictates a relatively slow advancing speed of the motor 3. For this reason, the cutting element will move back into the coal face at a slow speed, which is usual.
  • the motor 3 again advances the cutting element back into the coal seam under the control of current limiter 15.
  • the voltage detected by the threshold detector 22 is below the value which actuates servomotor 21 and, hence, the motor 3 advances the mining machine at low speed.
  • the feed speed is again increased as described above when the cutting element enters the coal face and the current through motor 2 increases. This is detected by the threshold detector 22.
  • the signal on lead 36 which is applied to the servomotor control 24 through R-C network 38 is also applied to an AND-circuit 40 through lead 41.
  • time delay circuit 39 is such that when two back and forth motions of the motor 3 occur under the conditions described, simultaneous signals will appear at the input to AND-circuit 40, causing an output signal to appear on lead 42.
  • This signal on lead 42 actuates the voltage reference controller 10 to stop the motor 3 through an R-C network 49.
  • the output of the voltage regulator 14 is also applied to a RPM monitor 43. Also applied to the RPM monitor 43 via lead 44 is the output of the tachometer generator 12 proportional to the actual speed of the motor 3.
  • the RPM monitor 43 will actuate a thyristor firing circuit 46 through lead 45 to decrease the firing angle of thyristor 47, which supplies current to the field winding 48 for motor 3.
  • the filed for motor 3 is reduced.
  • control means includes a voltage reference controller for producing an electrical signal proportional to the desired speed of said cutter drive motor, means for comparing said signal proportional to desired motor speed with a signal proportional to actual motor speed to derive an error signal, a voltage regulator responsive to said error signal, said current-limiting circuit being connected to the output of said voltage regulator, and a controllable power supply for said advancing drive motor connected to the output of said current-limiting circuit.
  • said means responsive to a current surge includes a second current limiter in shunt with said first-mentioned current limiter and is actuable to reverse said cutter drive motor only after said current surge persists beyond a predetermined period of time.
  • controllable power supply is of the reversible thyristor type.
  • said advancing drive motor is a direct current motor having a field winding supplied with power through a thyristor device, and means for reducing the power supplied to said field winding through said thyristor device where the speed of said advancing drive motor exceeds a predetermined limit.

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  • Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Mechanical Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Geology (AREA)
  • Power Engineering (AREA)
  • Control Of Direct Current Motors (AREA)
  • Earth Drilling (AREA)
  • Drilling And Exploitation, And Mining Machines And Methods (AREA)
US47529A 1969-06-20 1970-06-18 Apparatus for controlling and regulating a cutter hoist Expired - Lifetime US3633081A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19691931357 DE1931357C (de) 1969-06-20 Verfahren zum Steuern und Regeln einer Schrammaschinenwinde, die mit einem in seiner Drehzahl steuerbaren elektrischen Windenmotor ausgestattet ist

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JP (1) JPS5013722B1 (cs)
FR (1) FR2046932B1 (cs)
GB (1) GB1317045A (cs)

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3809975A (en) * 1973-01-22 1974-05-07 J Bartels Motor speed control apparatus for an electrically powered vehicle
US3988578A (en) * 1974-06-04 1976-10-26 Gebr. Eickhoff, Maschinenfabrik Und Eisengiesserei M.B.H. Method and apparatus for controlling the steplessly variable cutting rate and feed rate of mining machines
US4031437A (en) * 1975-07-10 1977-06-21 Concrete Cutting Equipment Inc. Work and feed control system for cutting machines
US4269448A (en) * 1976-11-11 1981-05-26 Anderson Strathclyde Limited Mineral mining machine cutter driving mechanism having a load sensing device to regulate the haulage speed of the machine when the cutter driving mechanism is overloaded
FR2475112A1 (fr) * 1980-02-02 1981-08-07 Gewerk Eisenhuette Westfalia Dispositif d'abattage pour exploitation miniere de fond avec regulation de la commande d'avance
US4639650A (en) * 1984-02-17 1987-01-27 Citizen Watch Co., Ltd. Control system for a cooling fan in an impact printer
US4698566A (en) * 1983-07-29 1987-10-06 Canon Kabushiki Kaisha Apparatus for controlling motor speed
US4828326A (en) * 1986-08-16 1989-05-09 Gebr. Eickhoff Maschinenfabrik U. Eisengiesserei Mbh Shearer loader for underground mining operation
EP0893199A2 (de) * 1997-07-23 1999-01-27 Elektra Beckum Aktiengesellschaft Stationäre Werkzeugmaschine, insbesondere Kreissägemaschine oder Fräsmaschine
EP2536536A1 (en) * 2010-02-17 2012-12-26 GARDENA Manufacturing GmbH Power tools
CN102943672A (zh) * 2012-11-19 2013-02-27 北方重工集团有限公司 采用自动修型的硬岩掘进机采煤机电控装置
CN103982181A (zh) * 2014-05-27 2014-08-13 重庆大学 一种采煤机高可靠性机电液短程截割传动系统及控制方法
US20140223926A1 (en) * 2011-09-30 2014-08-14 Mitsubishi Electric Corporation Heat pump device, heat pump system, and method for controlling inverter
CN106351656A (zh) * 2016-10-21 2017-01-25 南京六合佳源矿山设备有限公司 一种基于液压闭式传动系统无级变速采煤机截割部
CN109630110A (zh) * 2019-01-18 2019-04-16 天地科技股份有限公司 一种综采工作面煤层厚度自适应截割控制方法及电子设备

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3939546B2 (ja) * 2001-12-06 2007-07-04 パナソニック・イーブイ・エナジー株式会社 電動車両の電池電源装置

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2129049A (en) * 1938-04-18 1938-09-06 Gray & Co G A Means for regulating the rate of feed of a milling machine or other machine tool
US2809333A (en) * 1952-10-07 1957-10-08 Giddings & Lewis Constant chip thickness motor control system for machine tools

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1233356B (de) * 1965-08-02 1967-02-02 Eickhoff Maschinenfabrik Geb Elektrisch angetriebene Schraemmaschine
DE1534650A1 (de) * 1966-03-31 1969-02-20 Habegger Maschf Verfahren und Vorrichtung zur Regelung der Fraestrommelrotation und des Laengsvorschubs fuer Maschinen zum Vortrieb unterirdischer Strecken

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2129049A (en) * 1938-04-18 1938-09-06 Gray & Co G A Means for regulating the rate of feed of a milling machine or other machine tool
US2809333A (en) * 1952-10-07 1957-10-08 Giddings & Lewis Constant chip thickness motor control system for machine tools

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3809975A (en) * 1973-01-22 1974-05-07 J Bartels Motor speed control apparatus for an electrically powered vehicle
US3988578A (en) * 1974-06-04 1976-10-26 Gebr. Eickhoff, Maschinenfabrik Und Eisengiesserei M.B.H. Method and apparatus for controlling the steplessly variable cutting rate and feed rate of mining machines
US4031437A (en) * 1975-07-10 1977-06-21 Concrete Cutting Equipment Inc. Work and feed control system for cutting machines
US4269448A (en) * 1976-11-11 1981-05-26 Anderson Strathclyde Limited Mineral mining machine cutter driving mechanism having a load sensing device to regulate the haulage speed of the machine when the cutter driving mechanism is overloaded
FR2475112A1 (fr) * 1980-02-02 1981-08-07 Gewerk Eisenhuette Westfalia Dispositif d'abattage pour exploitation miniere de fond avec regulation de la commande d'avance
US4367900A (en) * 1980-02-02 1983-01-11 Gewerkschaft Eisenhutte Westfalia Mineral mining installation with electronic control
US4698566A (en) * 1983-07-29 1987-10-06 Canon Kabushiki Kaisha Apparatus for controlling motor speed
US4639650A (en) * 1984-02-17 1987-01-27 Citizen Watch Co., Ltd. Control system for a cooling fan in an impact printer
US4828326A (en) * 1986-08-16 1989-05-09 Gebr. Eickhoff Maschinenfabrik U. Eisengiesserei Mbh Shearer loader for underground mining operation
EP0893199A3 (de) * 1997-07-23 1999-06-16 Elektra Beckum Aktiengesellschaft Stationäre Werkzeugmaschine, insbesondere Kreissägemaschine oder Fräsmaschine
EP0893199A2 (de) * 1997-07-23 1999-01-27 Elektra Beckum Aktiengesellschaft Stationäre Werkzeugmaschine, insbesondere Kreissägemaschine oder Fräsmaschine
EP2536536A1 (en) * 2010-02-17 2012-12-26 GARDENA Manufacturing GmbH Power tools
US20130020102A1 (en) * 2010-02-17 2013-01-24 Gardena Manufacturing Gmbh Power Tools
US20140223926A1 (en) * 2011-09-30 2014-08-14 Mitsubishi Electric Corporation Heat pump device, heat pump system, and method for controlling inverter
US9829234B2 (en) * 2011-09-30 2017-11-28 Mitsubishi Electric Corporation Heat pump device, heat pump system, and method for controlling inverter
CN102943672A (zh) * 2012-11-19 2013-02-27 北方重工集团有限公司 采用自动修型的硬岩掘进机采煤机电控装置
CN102943672B (zh) * 2012-11-19 2015-01-07 北方重工集团有限公司 采用自动修型的硬岩掘进机采煤机电控装置
CN103982181A (zh) * 2014-05-27 2014-08-13 重庆大学 一种采煤机高可靠性机电液短程截割传动系统及控制方法
CN103982181B (zh) * 2014-05-27 2016-06-15 重庆大学 一种采煤机高可靠性机电液短程截割传动系统及控制方法
CN106351656A (zh) * 2016-10-21 2017-01-25 南京六合佳源矿山设备有限公司 一种基于液压闭式传动系统无级变速采煤机截割部
CN109630110A (zh) * 2019-01-18 2019-04-16 天地科技股份有限公司 一种综采工作面煤层厚度自适应截割控制方法及电子设备

Also Published As

Publication number Publication date
DE1931357A1 (de) 1970-12-23
DE1931357B2 (de) 1972-11-02
FR2046932B1 (cs) 1975-09-26
GB1317045A (en) 1973-05-16
JPS5013722B1 (cs) 1975-05-22
FR2046932A1 (cs) 1971-03-12

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