Spinning Machinery

Abstract

To provide a spinning machine supplying uniform voltage to all loads.SOLUTION: A spinning machine has a plurality of work units with electrical drive parts, in particular DC motors 10, 11, and 19, and at least two DC voltage sources 2.1 and 2.2 of voltages U1 and U2. The at least two DC voltage sources form DC voltage networks N1 and N2 respectively. Among the plurality of drive parts, in particular a current consuming part of the DC motor 19 is connected to a first DC voltage bar 3 and a third DC voltage bar 7, or a second DC voltage bar 4 and the third DC voltage bar 7 selectively. The two DC voltage networks N1 and N2 are operatively connected to a voltage compensation device 18 in order to compensate a voltage difference in the two DC voltage networks N1 and N2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a spinning machine comprising a plurality of working units with electric drives. The electric drives, in particular DC motors, have at least two DC voltage sources U1 and U2, which respectively constitute DC voltage networks N1 and N2. At least three DC voltage bars, which supply the drives, in particular DC motors, are connected to the at least two DC voltage sources in the following way: a first DC voltage bar is electrically operatively connected to the first DC voltage source, a second DC voltage bar is electrically operatively connected to the second DC voltage source, and a third DC voltage bar is electrically operatively connected to both the first and second DC voltage sources. Current consumers of the drives, in particular DC motors, are selectively connected to the first and third DC voltage bars or to the second and third DC voltage bars.

[0002] Background technology EP 1927686 A1 discloses a spinning machine with an electric drive and current supply for an electric motor, which includes a DC voltage source and an AC voltage source. At least one transformer is connected to the AC voltage network. Since many electric motors of very different configurations are used in spinning machines, particular attention must be paid to the individual requirements of each motor and the energy distribution through the machine when configuring the current supply. Therefore, it is proposed that the energy supply in the spinning machine should be designed to achieve an ideal voltage ratio depending on the motor type and its position in the machine. For this purpose, two rectifier groups are connected to the two transformer secondary windings, each of which is connected to two DC voltage bars, where the DC voltage bar is common to the two rectifier groups, resulting in three DC voltage bars. Different DC voltages, specifically 270 volts DC (direct current) and 540 volts DC, are present between these bars. The described energy supply concept allows motors in a spinning machine to be supplied with different voltages and operate efficiently. Thus, motors for driving various function carriers in the spinning machine, such as the drafting shaft or the ring frame lifting drive, can be supplied with, among other things, 540 volts DC. For example, another motor, provided for driving the spindle, can be operated with, among other things, 270 volts DC. Meanwhile, other motors are connected to the AC voltage network, for example, with 400 volts DC. Such motors drive, for example, doffers or suction units. The higher-level control unit is connected to the DC voltage network with 24 volts DC via a voltage converter to the 540 volts DC voltage network.

[0003] In the event of a network fault or a significant voltage drop, a corresponding reduction in the target speed is transmitted via the bus to all motors, whereupon the motors connected to this bus are switched into generator mode, whereby the energy stored in the rotating masses is converted into electrical energy as a result of the speed reduction and supplied to all loads present in the common intermediate circuit.

[0004] Problems arise when the load is asymmetric, i.e., when individual spindles are not operated or when there is a voltage drop. If the voltage drops, the current rises and there is a risk of an insufficient current supply. This must be prevented.

[0005] Disclosure of the Invention Therefore, the object of the present invention is to provide a uniform voltage to all loads.

[0006] The above-mentioned problem is solved by a spinning machine having the features of claim 1.

[0007] In the present invention, the spinning machine has a plurality of working units with electric drives, in particular DC motors. At least two DC voltage sources with voltages U1 and U2 respectively constitute DC voltage networks N1 and N2. At least three DC voltage bars are connected to the at least two DC voltage sources, which supply power to the drives, in particular DC motors. A first DC voltage bar is electrically operatively connected to the first DC voltage source, a second DC voltage bar is electrically operatively connected to the second DC voltage source, and a third DC voltage bar is electrically operatively connected to both the first and second DC voltage sources. The two DC voltage networks N1 and N2 preferably have different polarities, e.g., a voltage U1 having +270 volts is present in the DC voltage network N1, and a voltage U2 having -270 volts is present in the DC voltage network N2. Current consumers of multiple drives, particularly DC motors, are selectively connected to the first and third DC voltage bars or to the second and third DC voltage bars. The two DC voltage networks N1 and N2 are electrically operatively connected to a voltage compensator to compensate for the voltage difference between the two DC voltage networks N1 and N2. The voltage compensator ensures that substantially the same voltage is applied to the two DC voltage networks N1 and N2 even in the event of a voltage drop in the DC voltage network or when individual loads, such as spindles, are not in operation due to maintenance, etc. The voltage compensator thereby increases the voltage of the DC voltage network with the lower voltage by extracting energy from another DC voltage network with a higher voltage. The energy shift occurs until the difference between the two voltage levels is approximately zero. The sum of the voltages of the two DC voltage networks N1 and N2 remains substantially constant. Therefore, asymmetric loading of the DC voltage networks N1 and N2 does not occur.

[0008] It is particularly advantageous to assign a frequency converter to each DC voltage network N1 and N2 as a voltage compensator, with the frequency converter connected to an isolation transformer on the output side. The unequal voltages U1 and U2 in the two DC voltage networks N1 and N2 are compensated for by both the frequency converter and the isolation transformer. Each output of the frequency converter is connected to an isolation transformer instead of the motor lines on the output side. This allows the two voltages U1 and U2 to be compensated for. If one of the two voltages becomes too high, the voltage compensator shifts energy from U1 to U2 or vice versa. This creates, in a sense, floating intermediate points in the two intermediate circuits with the same voltage. Voltage U1 is applied to one frequency converter, while voltage U2 is applied to the other. The voltage compensator adjusts to eliminate the difference. The higher voltage is lowered, and the lower voltage is raised. The higher voltage is reduced while the lower voltage is increased by the same amount, thus keeping the totals U1 and U2 constant.

[0009] Further advantages are achieved when the spinning machine has operating units with DC motors on both sides, with one DC voltage network N1 or N2 each assigned to one of the operating units or drives, particularly the DC motors. Spinning machines with operating units with drives, particularly DC motors, arranged on both longitudinal sides are particularly advantageous in terms of their space requirements in a spinning factory. Ring spinning machines are typically configured as double-sided spinning machines. However, there are also many other spinning machines, such as air spinning machines, that are configured as single-sided spinning machines. In a particularly advantageous embodiment of the present invention, the two DC voltage networks of the spinning machine can be arranged as follows: the DC voltage network N1 can be assigned to the operating units on one machine side, and the DC voltage network N2 can be assigned to the operating units on the other machine side. This allows voltage compensation to be achieved between the two machine sides. This can be advantageous when different yarns are spun on the two machine sides and, accordingly, different maintenance cycles, such as package changes, are performed. The loads on the two machine sides are therefore different over time. Compensation of the two DC voltage networks N1 and N2 therefore brings advantages with regard to the equality of the two DC voltage networks N1 and N2.

[0010] It is particularly advantageous if the spinning machine is divided into several sections. Several operating units are arranged in each of these sections, with one DC voltage network N1 or N2 alternately assigned to each adjacent section. Many known spinning machines are divided into several sections. Here, the operating units are integrated with respect to their arrangement on the spinning machine. With respect to current supply and control, such operating units in each section can also be operated jointly. Spinning machines often have a large number of sections. For example, 24 operating units are integrated into each section on each side of the machine. In accordance with an advantageous embodiment of the present invention, if the DC voltage networks N1 and N2 alternately serve adjacent sections, a positive DC voltage U1 or a negative DC voltage U2 is applied to the motors of the operating units of each section alternately along the longitudinal direction of the spinning machine. Thus, the spinning machine is distributed in terms of voltage supply in the longitudinal direction. Therefore, unbalanced operation of the motors of the individual operating units of these sections can be compensated for with respect to the voltage supply.

[0011] It is also advantageous if the spinning machine has operating units on both sides and is divided into several sections. Several operating units are arranged in each of these sections, with one DC voltage network N1 or N2 alternately assigned to each of the opposite and adjacent sections. In this particularly advantageous configuration, not only are adjacent sections alternated, but also, within a section, on both machine sides, the opposite operating units are connected to different DC voltage networks N1 and N2. This allows for better compensation for different voltages that may occur in the individual operating units. This allows the spinning machine to operate with greater compensation for its own voltage supply.

[0012] It is particularly advantageous to connect additional drives, particularly DC motors, to the first and second DC voltage bars. By connecting the additional drives to the first and second DC voltage bars, the drives, particularly DC motors, can be operated at the additional voltage U3 in the spinning machine. This allows the motors to be optimally supplied with voltages appropriate for their specific tasks in the spinning machine. For example, the same motors tapping the first and third DC voltage bars or the second and third DC voltage bars can be operated at 270 volts, while the additional drives connected to the first and second DC voltage bars should be operated at U3 = 540 volts. These drives, particularly DC motors, operated at a higher voltage can be used, for example, for drafting and lifting devices, while the motors can be optimally operated at a lower voltage for spindle operation.

[0013] Likewise, it is advantageous for at least one inverter and / or DC voltage transformer with at least one AC motor to be arranged on two of these DC voltage bars for an additional voltage U4. This allows the voltage supply to supply not only DC motors but also AC motors with AC voltage. Alternatively or additionally, a DC voltage transformer for an additional DC voltage can be provided. This is possible by advantageously arranging the inverters and / or DC voltage transformers on the two DC voltage bars. Here, the inverter can be used, for example, for a doffer for spindle exchange or for the suction part of the spinning machine. The additional DC voltage of the DC voltage transformer, for example 24 volts, is used to power the machine's control unit.

[0014] It is particularly advantageous if the isolation transformer is a high-frequency transformer, which advantageously has a high conversion efficiency and a small size.

[0015] It is also advantageous if the frequency converter has a braking resistor to limit voltage peaks, via which excessive voltages from the DC voltage network N1 or N2 are reduced, thereby ensuring the safety of the entire system.

[0016] Furthermore, it is advantageous for the two DC voltage networks N1 and N2 to have symmetrical resistors to maintain the base level of the DC voltage networks N1 and N2. The symmetrical resistors are provided as a base level compensation, so that the intermediate circuit is not swept when the machine is switched on, for example. This reduces voltage peaks. Between each two of the three DC voltage bars, electrolytic capacitors are arranged in series, which distributes the voltage. To ensure uniform voltage distribution, these symmetrical resistors are connected in parallel with the electrolytic capacitors, which are also connected in series.

[0017] It is likewise advantageous if the two DC voltage networks N1 and N2 are of opposite polarity: for the voltage supply of the machines, a positive voltage, e.g. U1 = +270 volts, alternates with a negative voltage, e.g. U2 = -270 volts, so that in the event of a failure on one machine side, for example, the average voltage nevertheless remains unchanged and a floating midpoint can be maintained.

[0018] The spinning machine is configured in accordance with the above description, wherein the above features may be present individually or in any combination.

[0019] Instead of or in addition to the DC motors mentioned above, AC motors can also be used which are connected to a DC voltage bar by means of an inverter.

[0020] Further advantages of the present invention are described in the examples that follow. [Brief explanation of the drawings]

[0021] [Figure 1]FIG. 2 shows a schematic diagram of the inventive voltage supply of a spinning machine. [Figure 2] FIG. 1 shows a schematic diagram of a voltage compensation device. [Figure 3] 1 shows a schematic diagram of alternative voltage distributions in a spinning machine; [Figure 4] FIG. 10 shows a schematic diagram of another alternative voltage distribution in a spinning machine.

[0022] How to carry out the invention In the following description of the illustrated alternative embodiment, the same reference numerals are used for features whose construction and / or mode of operation are the same as those of the embodiments shown in the other figures. Unless otherwise stated, their construction and / or mode of operation correspond to the construction and / or mode of operation of the features described elsewhere. For clarity, similar components are only partially and sporadically referenced.

[0023] FIG. 1 shows a schematic diagram of the voltage supply according to the invention for a spinning machine, for example a ring, air or rotor spinning machine.

[0024] The spinning machine is connected to a primary three-phase AC voltage source 1, each having, for example, 400 volts. A DC voltage U3 of 540 volts is generated in a DC voltage network N3 by a storage unit 2. On the output side of the storage unit 2, a first DC voltage bar 3 is connected to a first DC voltage source 2.1, and a second DC voltage bar 4 is connected to a second DC voltage source 2.2. Two electrolytic capacitors 5 and 6 are connected in series between the two DC voltage bars 3 and 4. A third DC voltage bar 7 between the two electrolytic capacitors 5 and 6 distributes the voltage U3 between the two DC voltage bars 3 and 4. As a result, a voltage U1 = +270 volts is applied between the first DC voltage bar 3 and the third DC voltage bar 7 in the first DC voltage network N1. Similarly, a voltage U2 = -270 volts is present between the second DC voltage bar 4 and the third DC voltage bar 7, here in the second DC voltage network N2. It must be ensured that these two 270 volt voltages are approximately equal in value, so that even in the presence of unequal loads, there are no uneven voltages in the two DC voltage networks N1 and N2, and therefore the same basic level can be maintained. Therefore, two symmetrical resistors 8 and 9, similarly connected in series, are arranged in parallel with the two electrolytic capacitors 5 and 6.

[0025] A third DC voltage network N3, operating at 540 volts, is connected between the first DC voltage bar 3 and the second DC voltage bar 4. Loads are connected to this DC voltage network N3, the efficiency of which decreases with increasing voltage. For this purpose, a DC motor 10 is provided, for example, for the drafting device of the spinning machine and also for the lifting device for the ring rail or spindle rail. A further DC motor 11 can be used, for example, for the machine's suction device. These motors are protected by safety devices 12 and 13, respectively. Further overload protection of the DC voltage network N3 is provided by a thermostat 14, which disconnects the two DC voltage bars 3 and 4 in the DC voltage network N3 from the voltage supply in the event of excessive heating.

[0026] A DC voltage transformer 15 is arranged on the further extension of the two DC voltage bars 3 and 4 of the DC voltage network N3. The DC voltage transformer 15 converts the 540 V DC voltage into a 24 V DC voltage. This lower 24 V DC voltage is used, for example, for machine control via a safety device 16. Instead of or in addition to the DC voltage transformer 15, an inverter may be provided, to which an AC motor is connected.

[0027] The two DC voltage networks N1 and N2 are again protected against thermal overload via a thermostat 17. A positive voltage U1 = +270 volts is applied to the first DC voltage network N1, and a negative voltage U2 = -270 volts is applied to the second DC voltage network N2. To maintain the two DC voltage networks N1 and N2 at substantially the same voltage level despite the different loads present, a voltage compensator 18 is connected to the three DC voltage bars 3, 4 and 7. The voltage compensator 18 is shown in detail in FIG. 2.

[0028] A number of DC motors 19 are connected to the two DC voltage networks N1 and N2 for driving the spindles of the spinning machine. In addition to or as an alternative to the DC motors 19, AC motors can also be used which are connected to the DC voltage bars 3, 4, 7 by means of inverters.

[0029] The voltage supply is effected via a connecting element 20 and a DC voltage bus 21. The DC voltage bus 21 is used to distribute the voltage supply of the DC motors 19 along the spinning machine. The spinning machine has two sides 22 and 23. Each side 22 and 23 is provided with a number of sections 24' to 24n. The spindles or DC motors 19 are grouped into individual sections 24' to 24n. Thus, for example, ten spindles and DC motors 19 may be provided per section 24, 24' to 24n.

[0030] As can be seen from the schematic diagram of FIG. 1, DC voltage networks N1 and N2, with their own voltages U1 and U2, are alternately assigned to the machine side 22 of sections 24′ to 24m. Similarly, on another machine side 23, each section 24″ to 24n is alternately supplied with DC voltage networks N1 and N2, with their own voltages U1 and U2. Furthermore, mutually opposing sections 24′ and 24″, up to sections 24m and 24n, are alternately assigned to DC voltage networks N1 and N2, with their own voltages U1 and U2. This has the important advantage of ensuring approximately uniform loading of the DC voltage networks N1 and N2. Events occurring in individual DC motors 19 that cause voltage drops should often be assigned to individual machine sides 22 or 23. Accordingly, even utilization of the two DC voltage networks N1 and N2 is achieved by means of the other machine side 22 or 23, even if one of the machine sides 22 or 23 fails, so that voltage peaks in one of the DC voltage networks N1 or N2 are substantially prevented.

[0031] FIG. 2 shows a schematic diagram of the voltage compensation device 18 in more detail. The voltage compensation device 18 is connected to two DC voltage networks N1 and N2. As can be seen from FIG. 1, a DC voltage network N1 with a positive voltage U1 = +270 volts exists between the first supply voltage bar 3 and the third supply voltage bar 7. A second DC voltage network N2 with a negative voltage U2 = -270 volts exists between the second DC voltage bar 4 and the third DC voltage bar 7. The voltage of 540 volts applied between the second DC voltage bar 3 and the second DC voltage bar 4 is divided accordingly by two capacitors 5 and 6. The symmetry of the divided voltage is ensured by symmetrical resistors 8 and 9.

[0032] The voltage compensation device 18 has two frequency converters 25 and 26. On the output side, the two frequency converters 25 and 26 are connected to a high-frequency isolation transformer 27. To prevent overloading of the two frequency converters, braking resistors 28 and 29 are assigned to them, respectively. This allows the two voltages U1 and U2 of the two DC voltage networks N1 and N2 to be compensated. If one of the two voltages U1 or U2 is higher than the other voltage U2 or U1, this voltage is reduced and the other voltage is increased. This eliminates the difference between the two voltages, which allows the spinning machine to operate extremely stably.

[0033] FIG. 3 shows a schematic diagram of an alternative voltage distribution in a spinning machine. While in the voltage distribution according to FIG. 1 the voltage distribution in the individual sections 24'-24n alternates with respect to the DC voltage networks N1 and N2 or voltages U1 and U2, in the configuration of FIG. 3 the voltage distribution is alternately assigned to the operating units or sections 24'-24n on the two sides 22 and 23 of the spinning machine. Thus, sections 24'-24m are connected to the DC voltage network N2 with a voltage U2 = -270 volts. Sections 24''-24n are supplied from the DC voltage network N1 with a voltage U1 = +270 volts. Such an assignment of the voltage distribution can be advantageous when different loads on the two sides 22 and 23 are expected, which would result in voltage changes. Such voltage changes would load the two DC voltage networks N1 and N2 differently and must be compensated for by the voltage compensation device 18.

[0034] FIG. 4 shows a schematic diagram of another alternative voltage distribution in a spinning machine. Opposite sections 24'-24n here have the same voltage U1 or U2. Accordingly, sections 24' and 24'' are connected to a DC voltage network N1 with a voltage U1 = +270 volts. Adjacent sections 24m and 24n are connected to a DC voltage network N2 with a voltage U2 = -270 volts. Similar to the voltage distribution in FIG. 1, an alternating voltage distribution in the individual sections 24'-24n occurs here. However, mutually opposite sections 24'-24n are connected to the same DC voltage network N1 or N2. This has similar advantages to the voltage distribution in FIG. 1, but may have additional advantages when wiring a spinning machine.

[0035] The invention is not limited to the embodiments shown and described: variations within the scope of the claims are possible, as are combinations of features, even if these features are shown and described in different embodiments. [Explanation of symbols]

[0036] 1 AC voltage source 2 storage units 2.1 First DC voltage source 2.2 Second DC voltage source 3 First DC voltage bar 4 Second DC voltage bar 5 electrolytic capacitors 6 electrolytic capacitors 7. Third DC voltage bar 8 Symmetrical Resistors 9 Symmetrical Resistors 10 DC motor 11 DC motor 12 Safety equipment 13 Safety equipment 14 Thermostat 15 DC voltage transformer 16 Safety equipment 17 Thermostat 18 Voltage Compensator 19 DC motor 20 Connecting Elements 21 DC voltage bus 22 Machine side 23 Machine side 24 Sections 25 Frequency Converter 26 Frequency converter 27 High Frequency Isolation Transformer 28 Braking resistor 29 Braking resistor U1 Voltage U2 Voltage U3 Voltage U4 Voltage N1 DC voltage network N2 DC voltage network N3 DC voltage network

Claims

1. a plurality of working units each equipped with an electric drive, in particular a DC motor (10, 11, 19); At least two DC voltage sources (2.1, 2.2) of voltages U1 and U2; and At least two DC voltage sources (2.1, 2.2) constitute DC voltage networks N1 and N2, respectively; at least three DC voltage bars (3, 4, 7) supplying at least two of said DC voltage sources (2.1, 2.2) to a number of said drives, in particular said DC motors (10, 11, 19), a first DC voltage bar (3) is operatively connected to a first DC voltage source (2.1); a second DC voltage bar (4) in operative connection with a second DC voltage source (2.2); The third DC voltage bar (7) is operatively connected to the first DC voltage source (2.1) and the second DC voltage source (2.2). It is connected as follows: a plurality of said drive units, in particular current consumers of said DC motors (19), are selectively connected to said first DC voltage bar (3) and said third DC voltage bar (7) or to said second DC voltage bar (4) and said third DC voltage bar (7), the two DC voltage networks N1 and N2 are operatively connected to a voltage compensation device (18) for compensating for the voltage difference in the two DC voltage networks N1 and N2; Spinning machinery.

2. 2. The spinning machine according to claim 1, wherein a frequency converter (25, 26) is assigned to each of the DC voltage networks N1 and N2 as a voltage compensation device (18), and the frequency converters (25, 26) are connected on the output side to an isolation transformer (27).

3. 3. The spinning machine according to claim 1, wherein the spinning machine has operating units on both sides, and each of the operating units on one side (22, 23) is assigned to a DC voltage network N1 or N2.

4. 4. The spinning machine according to claim 1, wherein the spinning machine is divided into a plurality of sections (24'-24n), each of which is equipped with a plurality of operating units, and wherein one DC voltage network N1 or N2 is alternately assigned to adjacent sections (24'-24n).

5. 5. The spinning machine according to claim 1, wherein the spinning machine has operating units on both sides and is divided into a plurality of sections (24'-24n), each of which is arranged with a plurality of operating units, and wherein one DC voltage network N1 or N2 is alternately assigned to one side (22, 23) and the adjacent section (24'-24n).

6. 6. Spinning machine according to claim 1, characterized in that further drives, in particular DC motors (10, 11), are connected to the first DC voltage bar (3) and to the second DC voltage bar (4).

7. 7. The spinning machine according to claim 1, wherein at least one inverter and / or DC voltage transformer (15) with at least one AC motor is arranged on two of the DC voltage bars (3, 4, 7) for a further voltage U4.

8. 3. A spinning machine according to claim 2, wherein the isolation transformer (27) is a high frequency transformer.

9. 3. A spinning machine according to claim 2, wherein the frequency converters (25, 26) have braking resistors (28, 29) for limiting voltage peaks.

10. 10. Spinning machine according to claim 1, characterized in that the two DC voltage networks N1 and N2 have symmetrical resistors (8, 9) for maintaining a base level of the DC voltage networks N1 and N2.

11. 11. Spinning machine according to claim 1, wherein the two DC voltage networks N1 and N2 are of opposite polarity.

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