CS255032B1 - Electric drive of the mine cart's ramming device to the mining cage - Google Patents

Abstract

The present invention relates to an electric drive for a mine cart impact device in a mining cage. The drive motor has a controllable torque, which also allows adjustable acceleration of the drive as well as its rotation according to the operator's choice. The actuator consists of a three-phase asynchronous clamp motor, a three-phase transducer, two rheostats controlled by a single control lever, a disposable rectifier bridge, adjustable resistors, two-pole directional contactors, a single-phase current transformer and a DC power source.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the electric drive of a mining device to a mining cage. Its motor has a controllable torque that allows the drive to accelerate as well as rotate it in both senses of motion at the choice of the operator.

There are two known systems of mining cart impact devices:

1. Pneumatic or hydraulic.

2. Electric, with constant speed motor and one sense of rotation.

The pneumatic or hydraulic assembly uses a piston in the air or hydraulic cylinder to strike, the movement of the piston being effected by controlling the pressure medium. This system has considerable drawbacks; Domestic seals and sleeves of the pressure medium as well as the necessary hoses are etched and considerable leaks of the medium occur. This may interfere with workplace hygiene.

Moreover, both methods of the system require long bursts in the mines, since the pusher roller has a long length.

and

An electric motor with a fixed speed motor and one sense of rotation uses a three-phase electric motor with a cage anchor operating through a mechanical gearbox to a cable drum having a built-in planetary gearbox. The operator controls the two mechanical air-controlled brakes of this planetary gearbox so that the first brake can continuously change thrust in the rope wound on the rope drum and the second brake can achieve the opposite sense of rotation of the rope drum with constant sense of rotation of the electric motor.

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The rope wound on the rope drum controls the chain with a ram, which pushes the mining carts into the draw cage.

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The disadvantage of this second system is that it constitutes a very complex mechanism, which is demanding both in terms of machining precision and correct alignment of both wear brakes.

These disadvantages are overcome by the electric drive of the mining carriage pusher device according to the invention, consisting of a three-phase asynchronous cage motor, a three-phase transducer, two rheostats controlled by a common control lever, a single-phase rectifier bridge, two adjustable resistors, two three-phase and DC power supplies. The principle of the invention is that the three-phase winding of the asynchronous cage motor is connected to the three-phase power supply via an alternating winding of the three-phase transducer and via the first and second three-pole directional contactors. At the same time, the DC winding of the three-phase transducer is connected at one end to the coupling between the first rheostat and the second rheostat.

The other end of the DC winding of the three-phase transducer is connected via a first adjustable resistor to the positive pole of a DC voltage source, the negative pole of which is connected to the conductive portion of the control lever. The positive pole of the DC voltage source is further coupled to the coil connector of the first and second three-pole contactors. The negative pole of the DC voltage source is coupled via a mechanically operated bias contact of the first rheostat, a mechanically operated bias contact of the first rheostat, and an auxiliary bias contact of the second three-pole direction contactor with the second coil end of the first direction contactor. The negative pole of the source is also coupled via a mechanically actuated rest ruptive contact of the second rheostat, a mechanically actuated end working contact of the second rheostat, and an auxiliary rest contact of the first three-pole direction contactor with the second coil end of the second three-pole direction contactor. The mechanically actuated end working contact of the first rheostat is bypassed by 3

235 032 by a powerful working contact of the first three-pole directional contactor, while the mechanically operated end working contact of the second rheostat is bridged by the auxiliary working contact of the second three-pole directional contactor. A second adjustable resistor is connected to the secondary side of the single-phase current transformer and the alternating side of the single-phase rectifier bridge is connected to the DC side of the first adjustable resistor in parallel so that the positive pole of the single-phase rectifier bridge is connected to the positive pole.

The advantage of the electric drive of the mining carriage impact device according to the invention is that it is considerably simpler than the prior art systems, i.e. pneumatic or hydraulic systems and electrical systems with planetary gearboxes and its mechanical air-operated brakes. Simplification leads to higher work reliability, a significant reduction in steel consumption, production and assembly costs and, above all, a reduction in energy consumption.

In the accompanying drawing, FIG. 1 shows an example of an electric drive connection according to the invention and FIG. 2 shows the torque characteristics M = sf (n) of a three-phase asynchronous cage motor at its various terminal voltages.

FIG. 5 illustrates the operation of the single-phase current transformer and the first adjustable resistor for the DC current of the three-phase transducer.

2 and 3 indicate:

M = torque n = speed

U _n = nominal line voltage K) = reduced motor voltage

U2 = voltage at the motor greater than but less than U _R = DC side current of the single-phase rectifier bridge 16 at motor short-circuit state = excitation current in DC winding 14 of three-phase transducer 14A; current passage 1 ^ –14B = excitation current of DC winding 14 of three-phase transducer at zero current

Rj4 = resistance of DC winding 14 of three-phase transducer R _1? = resistance of the first adjustable resistor 17 Ug = constant voltage of DC power source 9 = natural torque characteristic of three-phase asynchronous cage motor 12 at its rated voltage —n = torque characteristic of three-phase asynchronous cage motor 12 at voltage <U _n = characteristic against mine truck torque = torque characteristics of the asynchronous cage motor 12 at voltage

The electric drive of the mining carriage pusher device comprises a three-phase asynchronous cage motor 12, a three-phase transducer, first and second rheostats 15A and 15B operated by a common control lever 11, a single-phase rectifier bridge 16, first and second adjustable resistors 17 and 18, a second three-pole directional contactor, a single-phase current transformer 15, and a DC voltage source 9.

The stator winding of the three-phase asynchronous cage motor 12 is connected via the AC winding 11 of the three-phase transducer and through the first and second three-pole direction contactors to the three-phase power supply 10. The DC winding 14 of the three-phase transducer is The other end of the DC winding 14 is via a first adjustable resistor 17 connected

2SS 032 only to the positive pole of the DC power supply 9, the negative pole of which is connected to the conductive part of the control lever 1. The positive pole of the DC power supply 9 is further coupled to the coil connector 5C and 6C of the first and second direction contactors. The negative pole of the DC power supply 9 is connected via a mechanically actuated terminal bias contact 2 of the first rheostat 13A, a mechanically actuated terminal bias contact 3 of the first rheostat 13A, and an auxiliary bias contact 6E of the second three-pole directional contactor.

The negative pole of the DC power supply 9 is also connected via a mechanically actuated terminal rest contact 7 of the second rheostat 13B, a mechanically actuated terminal operational contact 8 of the second rheostat 13B and an auxiliary rest contact 5B of the first three-pole direction contactor with the second end of the coil 6C of the second three-pole direction contactor. The mechanically operated end working contact 3 of the first rheostat 13A is bridged by the auxiliary working contact 5A of the first three-pole direction contactor. The mechanically operated end working contact 8 is bypassed by the auxiliary working contact 6A of the second three-pole direction contactor. A second adjustable resistor 18 is connected to the secondary side of the single-phase current transformer 13 and a alternating side of the single-phase rectifier bridge 16 is connected to the DC side and the first adjustable resistor 17 is connected in parallel with the positive pole of the single-phase rectifier bridge 16 connected to the positive pole. DC power supply 9.

The function of the electric drive of the bogie ram according to the invention is as follows:

If the control lever is deflected FORWARD, eg to the left from the neutral position, the temporarily mechanically operated end rest contact 2 is interrupted. If the control lever is further deflected to the left from the neutral position, the temporarily mechanically operated end working contact is closed. Thus, the closed trip auxiliary contact 6B of the second three-pole directional contactor for the reverse direction energizes the coil 5C of the first three-pole directional contactor for the FORWARD direction from the DC voltage source 9 shown in FIG. 1 as a battery.

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The closed auxiliary normally closed contact 6B allows the first three-pole directional contactor to be closed only when the second three-pole directional contactor is open. Thus, the auxiliary normally closed contact 6B blocks the simultaneous closing of both three-pole directional contactors which would cause a short-circuit on the three-phase mains 10.

By closing the first three-pole directional contactor with the main working contacts 5, its auxiliary working contact 5A closes and keeps the first three-pole directional contactor in the closed state even if the control lever 1 has left the mechanically actuated end working contact ^

Closing the first three-pole direction contactor is brought to the stator winding three-phase asynchronous squirrel-cage motor 12. The voltage U ^ is less than the nominal voltage U _R network 10, or in front of a three-phase asynchronous squirrel-cage motor 12 is connected in the alternating coil 11 of the three-phase transducer, which has a large reactance since the so-called deflection of the control lever 1 from the neutral position so far, the DC winding 14 of the three-phase transducer is only slightly excited, since the first rheostat 13 operated by the control lever in the FORWARD position still has a high resistance. Thus, the three-phase transducer is closed.

It can be seen from FIG. 2 that the natural torque characteristic 20, i.e. Msf (n) of a three-phase asynchronous cage motor 12, applied to the nominal voltage U _n , changed at a voltage U? To a characteristic 21 giving torque less than the counter torque characteristic 22. mining trucks when hitting them into the mining cage.

Only by further deflecting the control lever in the FORWARD direction does the resistance of the first rheostat 15A decrease continuously, and thus the three-phase transducer opens continuously and the engagement torque increases continuously. Once it is greater than counter-torque 22, the impacted mining carriages move.

2SS 032

At the greatest deflection of the control lever 1 in the direction of VP1? ED, a voltage U ₂ , substantially greater than the voltage but at a so-called residual reactance of the open three-phase transducer somewhat less than the nominal voltage U _{n of the} grid 10 This will achieve a characteristic of 25 ·

The possibility of continuously increasing the engagement torque has the advantage that there is no violent shock associated with any unwanted tipping of the mining trolley.

As soon as the bump hits the guide stop, its movement and thus the three-phase asynchronous cage motor 12 are stopped. In order to prevent the motor from consuming a large short-circuit current at a voltage U ₂ and not to overheat unnecessarily in the DC winding 14 of the three-phase transducer, and thus it automatically closes, so that on the three-phase asynchronous cage motor 12 only the voltage will be approximately equal to the voltage. This also reduces the short-circuit current drawn from the mains 10.

The self-closing of the transducer is caused by a voltage drop on the first adjustable resistor 17 _{y by a} direct current 3 ', from a single-phase rectifier bridge 16 connected by its alternating side to the secondary side of the single-phase current transformer 15>. .

The required voltage drop across the first adjustable resistor 17 can be adjusted once and for all by adjusting the resistance of the first adjustable resistor 17. The effect of the single phase rectifier bridge 16 and the single phase current transformer 15 can be adjusted once and for all by the second adjustable resistor 18 parallel connected to the alternating side of the single phase rectifier bridge 16 .

AND

2SS 032

In order for the three-phase transducer to close automatically, it is necessary to meet the condition that the positive terminal of the single-phase rectifier bridge is connected to the positive terminal of the DC power supply 9.

The function can be seen in Fig. 5 »from which it can be seen that under the given condition the excitation line (R ^ + R ^ y) · Σ14» where R ^ is the dc winding resistance of the three-phase transducer U and is the resistance of the first adjustable resistor 17 _Ijj- stream ejects · Ex voltage drop ^{to <^} 0 the coordinate origin and intersects the constant level voltage source 9 υθ at lower excitation current, and N ^ HB 'stream _Ι ·) 4ρ would dc winding three-phase transducer 14 is energized if not current. 1 ^ -> proportional current of three-phase asynchronous cage motor.

Upon returning the control lever 1 towards the neutral position, the end bias contact 2 opens and thus the first three-pole direction contactor is switched off, since the current in its coil 5C has been interrupted.

When the control lever 11 is deflected, i.e. to the right of the neutral position, the three-phase asynchronous cage motor 12 is reversed, or the rearward movement is not affected in a manner similar to that described in the FORWARD operation. The function will then be a mechanically operated terminal break contact 2 ^{and a} mechanically operated terminal break contact 8, instead of the terminal break contact 2 and the terminal break contact 5, the auxiliary break contact 5B and the auxiliary break contact 6A.

Claims (2)

OBJECT OF THE INVENTION 2SS 032 Electric propulsion of the mining carriage pusher, consisting of a three-phase asynchronous cage motor, a three-phase transducer, two rheostats operated by a common control lever, a single-phase rectifier bridge, two adjustable resistors, two three-pole directional contactors, a single-phase current transformer, wherein the three-phase winding of the asynchronous cage motor (12) is connected to the three-phase mains power supply (10) via the alternating winding (11) of the three-phase transducer and the first and second three-pole direction contactors. the coupling between the first rheostat (13A) and the second rheostat (13B), the second end of the DC winding (14) of the three-phase transducer is connected to the positive pole of the source (9) via a first adjustable resistor (17) ) a DC voltage whose negative pole is connected to the conductive part of the control lever (1), the positive pole of the DC voltage source (9) is further connected to the coil connector (5C, 6C) of the first and second three-pole direction contactors; the DC voltage is coupled via a mechanically actuated end bias contact (2) of the first rheostat (13A), a mechanically actuated end bias contact (3) of the first rheostat (13A) and an auxiliary bias contact (6B) of the second three-pole direction contactor with the second end of the coil (5C) of the first direction contactor, the negative pole of the source (9) is also connected via a mechanically operated idle contact (7) of the second rheostat (13B), a mechanically operated end working contact (8) of the second rheostat (13B) and an auxiliary idle contact (5B) of the first three-pole directional contactors with second coil end (6C) of second three-pole directional contactor, mechanically operated contact (3) is bypassed working auxiliary contact (5A) of the first directional three-pole contactors, mechanically operated while the terminal contact (8) is bypassed working auxiliary contact (6A) of the second three-pole contactor direction, on the secondary side of the single-phase current transformer (15) The second adjustable resistor (18) and the alternating side of the single-phase rectifier bridge (16) are connected to the DC side and the first adjustable from the porch (17) is connected in parallel with the positive side of the single-phase rectifier bridge (16). the DC voltage source (9).