EP3739090B1 - Rotor spinning machine and method for identifying a spinning rotor on a rotor spinning machine - Google Patents

Description

The present invention relates to a method for identifying a spinning rotor on a rotor spinning machine, in which the spinning rotor is mounted in a floating manner in an at least radially acting magnetic bearing and rotates in the bearing during spinning operation, and in which at least one variable system variable is compared with at least one reference value. Furthermore, the invention relates to a rotor spinning machine for using the method.

In a rotor spinning machine, textile fibers are compacted into yarns in a known manner by rotating a spinning rotor at high speed. The spinning rotor usually consists of a rotor cup, in which the yarn is produced, and a rotor shaft, which is used for torque transmission and coupling to a bearing. As is known, modern rotor spinning machines have a large number of individual work stations. These machines are able to produce different yarns, for example from different materials. There can be different requirements for the spinning rotors. Therefore, it is common to provide interchangeable spinning rotors of different sizes and/or shapes. In particular, the size and shape of the rotor cup can be varied. Changing the spinning rotors can change the permissible operating parameters of the work station or spinning machine. In order to ensure consistent yarn quality and high operational reliability, there is therefore a need for methods and devices for automatically identifying the installed spinning rotor.

From the DE 10 2007 028 935 A1 a method for detecting contamination or faults in a magnetic bearing of a rotor of an electrical machine is known in which during a lifting of the Rotor variable system variables are determined from different axial end positions and compared with reference values. If the deviation is too large, the machine is prevented from starting, for example. On the one hand, in the known method, only one degree of axial freedom of movement is used to determine the variable system size. On the other hand, errors or contamination are identified with the method and not the built-in spinning rotor. A similar procedure is from DE 44 04 243 A1 known in which to improve the safety of an open-end rotor spinning machine, the electrical energy supplied to the drive is monitored, with the drive being switched off when certain limit values are exceeded.

From the EP 0 922 797 A2 For example, a method is known in which a spinning rotor of an open-end spinning device is guided through the reading of an identification mark arranged on the spinning rotor by means of a sensor. Another method for identifying a spinning rotor is from EP 3 305 952 A1 known. There, an acceleration time required to reach a specific speed or the speed reached in a specific acceleration time is used as a characteristic variable for identifying the spinning rotor.

The object of the present invention is to further develop the known methods in such a way that an alternative identification of an installed spinning rotor is made possible.

The object is achieved by a method and a rotor spinning machine with the features of the independent patent claims.

The inventive method is used to identify a spinning rotor on a rotor spinning machine, wherein the spinning rotor is suspended in an at least radially acting electromagnetic bearing and during of a spinning mill rotates in storage. At least one variable system variable is compared with at least one reference value. It is proposed that the at least one variable system variable is an energy absorption of the bearing, a radial position of the spinning rotor and/or a resonant frequency of the spinning rotor.

The variable system variables mentioned depend directly on the physical properties of the spinning rotor and are therefore particularly suitable for identifying the spinning rotor. The particularly automatic detection of the spinning rotor by the rotor spinning machine can ensure that the spinning machine can only be operated with operating parameters that are adapted to the individual spinning rotor, for example. This restriction can ensure safe and efficient operation of the rotor spinning machine.

The at least one reference value is preferably established during a calibration. Various spinning rotors are installed in the rotor spinning machine and the corresponding variable system variables are determined. The calibration can be carried out, for example, by the manufacturer before delivery of the corresponding rotor spinning machine. However, it is also conceivable that the user of the rotor spinning machine carries out any necessary calibration himself.

The spinning rotor is suspended in an electromagnetic bearing that acts at least radially, with at least the radial position of the spinning rotor being actively influenced by the bearing. On the one hand, an active electromagnetic bearing can dampen undesired vibrations of the spinning rotor during the spinning operation. On the other hand, the active bearing can also contribute to the identification of the spinning rotor by influencing the radial position of the spinning rotor in a specific way and determining the effects of this influence (see below). Conversely, prior identification of the spinning rotor is also for control advantageous for storage. For example, if the mass of the spinning rotor is known, the effects of damping interventions in the bearing can be predicted and dosed accordingly. If the bearing also acts axially, it is of course also conceivable that an axial position of the spinning rotor is also actively influenced by the bearing.

A radial position of the spinning rotor is detected by at least one sensor and/or by the bearing. The sensor can be used to determine the radial position of the spinning rotor as a variable system variable. The sensor can also detect vibrations of the spinning rotor and thus serve as a basis for dampening interventions in the bearing, for example. The sensor can be designed as an inductive, capacitive, magnetic or optical displacement sensor. An embodiment as an eddy current sensor is also conceivable. By measuring vibrations, it is also possible to determine the resonance frequency of the spinning rotor (see below).

At least one change in the position of the spinning rotor can also be detected by a signal induced in the bearing. An additional position sensor can thus possibly be dispensed with, or the accuracy of the position detection can be increased by the shared use of at least one sensor and the bearing. It is also conceivable that an axial position of the spinning rotor is detected by a sensor.

It is also an advantage if the position of the floating spinning rotor is varied in such a way that the energy consumption of the bearing is minimal and the position is then compared with at least one position reference value. On the one hand, a minimized energy consumption of the bearing is advantageous for the energy consumption of the rotor spinning machine. On the other hand, the position, in particular the radial position, can allow conclusions to be drawn about the physical properties of the spinning rotor when the energy absorption of the bearing is minimized. This is fundamental to the fact that there is only one position of minimum energy absorption of the bearing for a specific spinning rotor, and this depends, for example, on the mass of the spinning rotor. Varying the position of the spinning rotor and minimizing the energy absorption of the bearing can take place while the spinning rotor is not rotating. On the other hand, it is conceivable to carry out the method with the spinning rotor rotating.

It is advantageous if the spinning rotor is brought into a defined radial position and the energy consumption of the bearing is then compared with at least one energy consumption reference value. In contrast to the procedure described above, it is possible to fix the radial position of the spinning rotor and to determine the energy absorption of the bearing at this position. Accordingly, this energy absorption is again characteristic of the respective spinning rotor, since it depends, for example, on its mass. As before, the process preferably takes place with a non-rotating spinning rotor. However, it is also conceivable to determine the energy absorption of the bearing when the spinning rotor is rotating in a fixed radial position. This then depends on the vibrations or characteristic imbalances of the spinning rotor and can therefore be used for identification.

The spinning rotor is advantageously made to oscillate by the bearing and the resonant frequency of the spinning rotor is determined from a decay behavior of the oscillation. This is then compared with at least one resonant frequency reference value. The resonant frequency of the spinning rotor as a rigid body is also characteristic of a specific shape and mass and is therefore suitable for identification. The active bearing can give the spinning rotor a movement impulse and the decay time of the resulting vibration can be determined with the sensor or via the bearing. The respective spinning rotor can be identified from this vibration behavior.

In addition, it is advantageous if, during an acceleration of the spinning rotor, the resonance frequency of the spinning rotor is determined from an increase in an amplitude of an oscillation of the spinning rotor and this is then compared with at least one resonance frequency reference value. This exploits the fact that the spinning rotor vibrates by itself during rotation. The maximum amplitude of vibration occurs when the spinning rotor rotates at a speed equal to its resonant frequency. This speed is also called the critical speed. However, the spinning rotor does not have to be accelerated to the critical speed for the process. The critical speed can be extrapolated from the increase in the amplitude of the vibration. However, it would be conceivable to accelerate the spinning rotor to above the critical speed and to measure the resonance frequency directly. An extrapolation would then not be necessary. In any case, the amplitude of the vibration can be measured via the sensor already described and/or by signals induced in the bearing.

It is particularly advantageous if a mass, a shape, a volume and/or a material of the spinning rotor is determined from the comparison of the variable system variable with the reference value. The physical properties mentioned are closely related to each other and directly influence the variable system variables described. It is conceivable that one of the listed physical properties is the same for different spinning rotors. For example, it is conceivable that two spinning rotors have the same mass but not the same shape or the same volume. It can therefore make sense to determine several of the properties in order to arrive at a clear identification.

For safe and efficient operation of the rotor spinning machine, it is particularly advantageous if a functional scope of the spinning operation is determined from the comparison of the variable system variable with the reference value.

Different spinning rotors can withstand different loads and are particularly suitable for the production of different yarns. The range of functions of the spinning operation means, on the one hand, general operating parameters of the rotor spinning machine. For example, the maximum speed or a maximum torque can be limited during the acceleration of the spinning rotor, depending on the result of the identification. Cleaning or maintenance intervals can also be adapted to the spinning rotor. On the other hand, it is also conceivable that an operator of the rotor spinning machine, preferably in connection with an article management system, is only offered specific yarns for production depending on the installed spinning rotor. An article management system manages rotor spinning machine settings for the production of specific yarns. It is conceivable that when a specific yarn or recipe is selected from the item management system, the installation of a specific spinning rotor will be suggested.

The rotor spinning machine according to the invention has at least one work station. The at least one work station in turn comprises a spinning rotor which is mounted in a floating manner in an at least radially acting electromagnetic bearing and which rotates within the bearing during a spinning operation. Furthermore, the at least one work station includes a controller. It is proposed that the controller be designed to identify the spinning rotor, with at least one variable system variable being compared with at least one reference value, with the at least one variable system variable being an energy absorption of the bearing, a radial position of the spinning rotor and/or a resonance frequency of the spinning rotor is. As already described, a preferably automated identification of the built-in spinning rotor based on its physical properties can improve the safety and the efficiency of the operation of the rotor spinning machine. Of course, the spinning rotor or at least parts of the spinning rotor of the rotor spinning machine can be exchanged. In particular, the rotor cup of the spinning rotor is exchangeable.

The rotor spinning machine can have a large number of work stations which, in particular, can be operated at least partially independently of one another. Each job has its own spinning rotor, which is preferably driven by an individual drive. Other features of the workplace of the rotor spinning machine can be, in particular, opening and winding rollers as well as yarn sensors and suction devices. The control of the work station can be connected to controls of other work stations and/or to a higher-level machine control. The controller can be designed as an integrated circuit, for example.

The bearing is an electromagnetic bearing with at least one electromagnet. Such a bearing allows the active regulation of the position of the spinning rotor and thus, for example, an orientation in which the bearing and/or the drive consumes little energy. Vibrations of the spinning rotor can also be dampened by the bearing or minimized by advantageous positioning of the spinning rotor. As already described, the active bearing can be used for the method of identifying the spinning rotor, on the one hand by minimizing the energy consumption of the bearing by varying the position of the spinning rotor, or by determining a characteristic energy consumption of the bearing for a given position. The bearing can have several bearing elements, for example bearing rings. In particular, two bearing elements are provided. The position of the spinning rotor can be regulated via the current flowing in a coil of the at least one electromagnet. The storage can have both electromagnets and permanent magnets. In the event of a failure of the bearing, an additional safety bearing is preferably provided.

The controller is connected to at least one sensor for detecting a position and/or a movement of the spinning rotor. The sensor can be in the form of an inductive, capacitive, magnetic or optical displacement sensor be. An embodiment as an eddy current sensor is also conceivable. In particular, two sensors are provided. As already described, the bearing can be used to detect the movement of the spinning rotor as an alternative or in addition. For this purpose, current and/or voltage changes in the coils of the bearing can be evaluated.

In particular, it is advantageous if the bearing also acts axially or an additional axial bearing is provided. If the bearing has an axial effect, at least one additional axial bearing element may be required. Controlling the position of the spinning rotor in the radial and axial directions together can be beneficial by further reducing power consumption and vibration.

The additional axial bearing can also be magnetic and, in particular, active. The axial bearing preferably has at least one electromagnet. It is also conceivable that the axial bearing has at least one permanent magnet.

A further advantage becomes apparent when the control is connected to an item management system. An article management system can provide an operator of the rotor spinning machine with a database of yarns to be produced with the associated operating parameters and setting values for the rotor spinning machine. The corresponding operating parameters and setting values can preferably be applied automatically to the rotor spinning machine when a yarn to be produced is selected. The selection of possible yarns can depend on the built-in spinning rotor or a successful identification of the spinning rotor. The article management system can be designed as a central computer, integrated into a controller of the rotor spinning machine, or be available from a central location via the Internet. It is conceivable that the database of the parts management system also contains reference values for the variable system variables.

Another great advantage is when the controller has a memory for position reference values, energy consumption reference values and/or resonant frequency reference values. Using the memory, it is particularly easy to make these values available individually for each work station and to use them for the identification of the spinning rotor according to the invention. The reference values can be determined, for example, by the manufacturer of the rotor spinning machine and in particular during initial commissioning and stored in the memory. It is alternatively conceivable for these reference values to be stored in a memory, in particular a central memory, and for the controller to be connected to the memory, or for these reference values to be made available by the manufacturer via the Internet, for example.

Figur 1

eine Frontansicht einer erfindungsgemäßen Rotorspinnmaschine,

Figur 2

einen Spinnrotor der erfindungsgemäßen Rotorspinnmaschine mit Lagerung und Antrieb, und

Figur 3

ein weiteres Ausführungsbeispiel eines Spinnrotors der erfindungsgemäßen Rotorspinnmaschine.

Further advantages of the invention are described in the following exemplary embodiments. It shows:

figure 1

a front view of a rotor spinning machine according to the invention,

figure 2

a spinning rotor of the rotor spinning machine according to the invention with storage and drive, and

figure 3

another embodiment of a spinning rotor of the rotor spinning machine according to the invention.

In the following description of the figures, the same reference symbols are used for features that are identical and/or at least comparable in the various figures. The individual features, their design and/or mode of action are usually only mentioned when they are first mentioned explained in detail. If individual features are not explained in detail again, their design and/or mode of action corresponds to the design and mode of action of the features already described that have the same effect or have the same name.

figure 1 shows a rotor spinning machine 1 according to the invention with several work stations 2, in which textile fibers are spun into yarns 3 in the known rotor spinning process. The yarn 3 is wound onto a spool 4 in each case. The work stations 2 each have a spinning rotor 5 with a magnetic bearing 6 and a control 7 (see FIG figure 2 ). The controller 7 is designed in each case to identify the spinning rotor 5, with at least one energy absorption of the bearing 6, a radial position of the spinning rotor 5 and/or a resonance frequency of the spinning rotor 5 being compared as a variable system variable with at least one corresponding reference value.

figure 2 shows a view of the spinning rotor 5 installed in one of the work stations 2 with the magnetic bearing 6 and the controller 7. The spinning rotor 5 consists of a rotor cup 8 and a rotor shaft 9, with the rotor cup 8 and rotor shaft 9 preferably being detachably connected to one another. In the spinning operation, yarn production takes place in the rotor cup 8 , the rotor cup 8 having a specific shape that is particularly suitable for the production of specific yarns 3 . Depending on requirements, the entire spinning rotor 5 or at least the rotor cup 8 can be exchanged, which makes it necessary for the controller 7 to identify the spinning rotor 5 as automatically as possible.

The rotor shaft 9 is used for coupling to the bearing 6 and a drive 10. The drive 10 can be designed, for example, as an electric motor, in which case the rotor shaft 9 can be the rotor of the electric motor at the same time. In this example, the bearing 6 has two bearing elements 11 which are preferably designed as bearing rings. The storage elements 11 can have electromagnets and possibly permanent magnets and are connected to the controller 7 .

The controller 7 can, for example, actively regulate the radial position of the floating spinning rotor 5 and, for example, dampen unwanted vibrations during the spinning operation. The bearing elements 11 can serve as position sensors for the spinning rotor 5 since movements of the spinning rotor 5 lead to changes in the current and/or the voltage in the electromagnets of the bearing elements 11.

As already described, several procedures are conceivable for identifying the spinning rotor 5 . For example, the position of the spinning rotor 5 can be varied in such a way that the energy absorption of the bearing 6, which is necessary to keep the spinning rotor 5 in suspension, is minimal. On the other hand, the energy absorption of the bearing 6 can be determined at a predetermined position of the spinning rotor 5.

The spinning rotor 5 can also be identified based on its resonant frequency. The resonance frequency is characteristic of the mass and the shape of the spinning rotor 5. On the one hand, the resonance frequency can be determined from the increase in the amplitude of the vibration of the spinning rotor 5 during the accelerated rotation. On the other hand, the spinning rotor 5 can also be made to vibrate by the bearing 6 and the resonant frequency can be determined on the basis of the decay behavior, in particular the decay time, of the vibration. In each of these cases, a variable system variable is determined which depends on the physical properties of the spinning rotor 5 and which allows the spinning rotor 5 installed in the work station 2 of the rotor spinning machine 1 to be assigned by means of a comparison with known reference values.

figure 3 shows the view of another spinning rotor 5 of the rotor spinning machine 1 according to the invention. In this embodiment, the shape of the Spinning rotor 5, in particular the shape of the rotor cup 8 changed. The identification of the spinning rotor 5 according to the method according to the invention will therefore lead to a different result compared to the previous exemplary embodiment. The rotor shaft 9 is connected to an additional axial bearing 12, which is also designed as a magnetic bearing, for example. In contrast to the preferably active radial bearing 6, the axial bearing 12 can be passive, for example. In this example, the controller 7 is connected to a sensor 13 for measuring the radial position of the spinning rotor 5 in addition to the bearing elements 11 of the radial bearing 6 . On the one hand, this sensor 13 can only measure the variable system variable of the position of the spinning rotor 5, or on the other hand it can be used together with the position or movement information of the bearing 6. Of course, the sensor 13 can also be used to measure movements, such as vibrations, of the spinning rotor 5 . Other sensors 13 are also conceivable.

The controller 7 is also connected to an article management system 14 that contains operating parameters and setting values for the rotor spinning machine 1 for producing different yarns 3 . With the method according to the invention for identifying the spinning rotor 5, a preselection of the recipes provided by the article management system 14 for the production of yarns 3 can be made, for example, depending on the current spinning rotor 5. It is also conceivable for a recipe selected by an operator to be executed only after the spinning rotor 5 has been successfully identified, or for the operator to be prompted to install a different spinning rotor 5 .

Reference List

1

rotor spinning machine

2

place of work

3

yarn

4

Kitchen sink

5

spinning rotor

6

storage

7

steering

8th

rotor cup

9

rotor shaft

10

drive

11

bearing element

12

axial bearing

13

sensor

14

item management system

Claims (11)

1. A method for identifying a spinning rotor (5) on a rotor spinning machine (1), wherein the spinning rotor (5) is mounted in a suspended manner in an at least radially acting electromagnetic bearing (6) and rotates in the bearing (6) during a spinning operation, wherein at least one radial position of the spinning rotor (5) is actively influenced by the bearing (6), and wherein at least one variable system variable is compared to at least one reference value,
   characterized in that
   the at least one variable system variable is an energy consumption of the bearing (6), the radial position of the spinning rotor (5), detected by at least one sensor (13) and/or by the bearing (6) and/or a resonant frequency of the spinning rotor (5).
2. The method as claimed in claim 1, characterized in that the radial position of the suspended spinning rotor (5) is varied in such a way that the energy consumption of the bearing (6) is minimized and, thereafter, the position is compared to at least one position reference value.
3. The method as claimed in one of the preceding claims, characterized in that the spinning rotor (5) is brought into a defined radial position and, thereafter, the energy consumption of the bearing (6) is compared to at least one energy consumption reference value.
4. The method as claimed in one of the preceding claims, characterized in that the spinning rotor (5) is caused, by the bearing (6), to oscillate and the resonant frequency of the spinning rotor (5) is determined from a subsidence behavior of the oscillation and, thereafter, the resonant frequency is compared to at least one resonant frequency reference value.
5. The method as claimed in one of the preceding claims, characterized in that the resonant frequency of the spinning rotor (5) is determined during an acceleration of the spinning rotor (5) on the basis of an increase of an amplitude of an oscillation of the spinning rotor (5) and, thereafter, the resonant frequency is compared to at least one resonant frequency reference value.
6. The method as claimed in one of the preceding claims, characterized in that a mass, a shape, a volume, and/or a material of the spinning rotor (5) are/is determined from the comparison of the variable system variable with the reference value.
7. The method as claimed in one of the preceding claims, characterized in that a functional scope of the spinning operation is determined on the basis of the comparison of the variable system variable with the reference value.
8. A rotor spinning machine (1) comprising at least one workstation (2) including a spinning rotor (5), which is mounted in a suspended manner in an at least radially acting electromagnetic bearing (6), having at least one electromagnet, which rotates within the bearing (6) during a spinning operation, wherein the workstation (2) also comprises a control system (7), wherein the control system (7) is designed for carrying out an identification of the spinning rotor (5), wherein at least one variable system variable is compared with at least one reference value, characterized in that the at least one variable system variable is an energy consumption of the bearing (6), a radial position of the spinning rotor (5), wherein the control system (7) is connected to at least one sensor (13) for detecting the position and/or a movement of the spinning rotor (5) and/or a resonant frequency of the spinning rotor (5).
9. The rotor spinning machine (1) as claimed in claim 8, characterized in that the bearing (6) additionally acts in an axial direction or an additional axial bearing (12) is provided.
10. The rotor spinning machine (1) as claimed in claim 8 or 9, characterized in that the control system (7) is connected to an article management system (14).
11. The rotor spinning machine (1) as claimed in one of the claims 8, 9 or 10, characterized in that the control system (7) comprises a memory or that the control system (7) is connected to a memory, in particular to a central memory, in order to store position reference values, energy consumption reference values, and/or resonant frequency reference values.

Images