Yarn return unit for returning a yarn as well as a workstation of a textile machine comprising a yarn return unit

Abstract

A method is provided for identifying a spinning rotor on a rotor spinning machine, wherein the spinning rotor is mounted in a suspended manner in a radially acting magnetic bearing during a spinning operation. At least one system variable that varies between different spinning rotors is identified. The system variable is detected and compared to at least one reference value. The system variable is one or a combination of: an energy consumption of the magnetic bearing; a radial position of the spinning rotor; or a resonant frequency of the spinning rotor. A rotor spinning machine that carries out the method is also provided.

Claims

1. A method for identifying a spinning rotor on a rotor spinning machine from other different types of spinning rotors, wherein the spinning rotor is mounted in a suspended manner in an at least a radially acting magnetic bearing and rotates in the bearing during a spinning operation, the method comprising: identifying at least one system variable that varies between different types of spinning rotors; detecting the system variable; comparing the detected system variable to at least one reference value; wherein the system variable is one or a combination of: an energy consumption of the magnetic bearing; a radial position of the spinning rotor; or a resonant frequency of the spinning rotor; and based on the comparison of the detected system variable and the reference value, one or a combination of the following physical characteristics of the spinning rotor that differentiate one type of spinning rotor from a different type of spinning rotor are determined: a mass of the spinning rotor, a volume of the spinning rotor, a material of the spinning rotor, and dimensions of a size or shape of the spinning rotor.

2. The method as in claim 1, wherein at least the radial position of the spinning rotor is actively influenced by the magnetic bearing.

3. The method as in claim 2, wherein the radial position of the spinning rotor is detected by at least one sensor or by the magnetic bearing.

4. The method as in claim 2, wherein the radial position of the spinning rotor is varied in such a way that the energy consumption of the magnetic bearing is minimized and, thereafter, the radial position is compared to at least one radial position reference value.

5. The method as in claim 2, wherein the spinning rotor is brought into a defined radial position and, thereafter, the energy consumption of the magnetic bearing is compared to at least one energy consumption reference value.

6. The method as in claim 1, wherein the spinning rotor is caused, by the magnetic bearing, to oscillate and the resonant frequency of the spinning rotor is determined from a subsidence behavior of the oscillation and, thereafter, the resonant frequency is compared to at least one resonant frequency reference value.

7. The method as in claim 1, wherein the resonant frequency of the spinning rotor is determined during an acceleration of the spinning rotor based on an increase of an amplitude of an oscillation of the spinning rotor and, thereafter, the resonant frequency is compared to at least one resonant frequency reference value.

8. The method as in claim 1, further comprising establishing a functional scope of the spinning operation based on the comparison of the system variable with the reference value.

9. A rotor spinning machine, comprising: at least one workstation, the workstation comprising a spinning rotor mounted in a suspended manner in a radially acting magnetic bearing such that the spinning rotor rotates within the magnetic bearing during a spinning operation; the workstation further comprising a control system configured to identify of the spinning rotor from other different types of spinning rotors by comparing a system variable that varies between different types of spinning rotors with a reference value; wherein the system variable is one or a combination of: an energy consumption of the magnetic bearing; a radial position of the spinning rotor; or a resonant frequency of the spinning rotor; and based on the comparison of the detected system variable and the reference value, the control system configured to determine one or a combination of the following physical characteristics of the spinning rotor that differentiate the spinning rotor from other different types of spinning rotors: a mass of the spinning rotor, a volume of the spinning rotor, a material of the spinning rotor, and dimensions of a size or shape of the spinning rotor.

10. The rotor spinning machine as in claim 9, wherein the magnetic bearing comprises an electromagnetic bearing with at least one electromagnet.

11. The rotor spinning machine as in claim 9, wherein the control system is connected to a sensor that is configured to detect a position or a movement of the spinning rotor.

12. The rotor spinning machine as in claim 9, wherein the magnetic bearing additionally acts in an axial direction on the spinning rotor.

13. The rotor spinning machine as in claim 9, further comprising an additional axial bearing that acts in an axial direction on the spinning rotor.

14. The rotor spinning machine as in claim 9, wherein the control system is connected to an article management system.

15. The rotor spinning machine as in claim 9, wherein the control system comprises or is connected to a memory that stores the reference values.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages of the invention are described in the following exemplary embodiments. Wherein

(2) FIG. 1 shows a front view of a rotor spinning machine according to the invention,

(3) FIG. 2 shows a spinning rotor of the rotor spinning machine according to the invention, including a bearing and a drive, and

(4) FIG. 3 shows one further exemplary embodiment of a spinning rotor of the rotor spinning machine according to the invention.

DETAILED DESCRIPTION

(5) Reference will now be made to embodiments of the invention, one or more examples of which are shown in the drawings. Each embodiment is provided by way of explanation of the invention, and not as a limitation of the invention. For example features illustrated or described as part of one embodiment can be combined with another embodiment to yield still another embodiment. It is intended that the present invention include these and other modifications and variations to the embodiments described herein.

(6) In the following description of the figures, the same reference signs are utilized for features that are identical and/or at least comparable in each of the various figures. The individual features, their embodiment and/or mode of operation are explained in detail usually only upon the first mention thereof. If individual features are not explained in detail once more, their embodiment and/or mode of operation correspond/corresponds to the embodiment and mode of operation of the features that act in the same way or have the same name and have already been described.

(7) FIG. 1 shows a rotor spinning machine 1 according to the invention, comprising multiple workstations 2 in which textile fibers are spun into yarns 3 in the known rotor spinning process. The yarn 3 is wound onto a package 4 in each case. The workstations 2 each comprise a spinning rotor 5 including a magnetic bearing 6 and a control system 7 (see FIG. 2). The control system 7 is designed, in each case, for carrying out an identification of the spinning rotor 5, wherein at least one energy consumption of the bearing 6, a radial position of the spinning rotor 5, and/or a resonant frequency of the spinning rotor 5, as a variable system variable, are/is compared to at least one appropriate reference value.

(8) FIG. 2 shows a view of the spinning rotor 5 installed in one of the workstations 2, comprising the magnetic bearing 6 and the control system 7. The spinning rotor 5 is composed of a rotor cup 8 and a rotor shaft 9, wherein the rotor cup 8 and the rotor shaft 9 are preferably detachably connected to one another. The yarn production takes place in the rotor cup 8 during the spinning operation, wherein the rotor cup 8 has a certain shape, which is particularly suitable for producing certain yarns 3. The entire spinning rotor 5 or at least the rotor cup 8 can be replaced according to demand, which makes it necessary to carry out an identification of the spinning rotor 5, as automatically as possible, with the aid of the control system 7.

(9) The rotor shaft 9 is utilized for the coupling to the bearing 6 and a drive 10. The drive 10 can be designed, for example, as an electric motor, wherein, in this case, the rotor shaft 9 can simultaneously be the rotor of the electric motor. In this example, the bearing 6 comprises two bearing elements 11, which are preferably designed as bearing rings. The bearing elements 11 can comprise electromagnets and, possibly, permanent magnets and are connected to the control system 7.

(10) The control system 7 can, for example, actively control, by way of a closed-loop system, the radial position of the suspended spinning rotor 5 and, for example, dampen unintended vibrations during the spinning operation. The bearing elements 11 can be utilized as position sensors of the spinning rotor 5, since movements of the spinning rotor 5 result in changes of the current and/or of the voltage in the electromagnets of the bearing elements 11.

(11) As described above, multiple 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 consumption of the bearing 6, which is necessary in order to hold the spinning rotor 5 in suspension, is minimized. On the other hand, the energy consumption of the bearing 6 can be determined when the spinning rotor 5 is in a predefined position.

(12) The spinning rotor 5 can also be identified on the basis of its resonant frequency. The resonant frequency is characteristic for the mass and the shape of the spinning rotor 5. On the one hand, the resonant frequency can be determined on the basis of the increase of 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 caused, by the bearing 6, to oscillate and the resonant frequency can be determined on the basis of the subsidence behavior, in particular the decay time, of the oscillation. In each of these cases, a variable system variable is determined, which depends on the physical properties of the spinning rotor 5 and which, with the aid of a comparison to known reference values, allows for an assignment of the spinning rotor 5 installed into the workstation 2 of the rotor spinning machine 1.

(13) FIG. 3 shows the view of one further spinning rotor 5 of the rotor spinning machine 1 according to the invention. In this exemplary embodiment, the shape of the spinning rotor 5, in particular the shape of the rotor cup 8, is changed. The identification of the spinning rotor 5 according to the method according to the invention will therefore yield a different result as compared to the preceding exemplary embodiment. The rotor shaft 9 is connected to an additional axial bearing 12, which is also designed, for example, as a magnetic bearing. In contrast to the preferably active radial bearing 6, the axial bearing 12 can be, for example, passive. The control system 7 in this example is connected, not only to the bearing elements 11 of the radial bearing 6, but also to a sensor 13 for measuring the radial position of the spinning rotor 5. This sensor 13 can, on the one hand, exclusively measure the variable system variable of the position of the spinning rotor 5, or, on the other hand, be used together with the pieces of position and/or movement information of the bearing 6. Of course, movements, such as vibrations, of the spinning rotor 5 can also be measured with the aid of the sensor 13. Further sensors 13 are also conceivable.

(14) Moreover, the control system 7 is connected to an article management system 14, which contains operating parameters and setting values for the rotor spinning machine 1 for manufacturing different yarns 3. With the aid of the method according to the invention for identifying the spinning rotor 5, a preselection of the recipes, made available by the article management system 14, for manufacturing yarns 3 can be carried out, for example, depending on the present spinning rotor 5. It is also conceivable that a recipe selected by an operator is implemented only after a successful identification of the spinning rotor 5, or the operator is prompted to install another spinning rotor 5.

(15) The present invention is not limited to the represented and described exemplary embodiments. Modifications within the scope of the claims are also possible, as is any combination of the features, even if they are represented and described in different exemplary embodiments.

LIST OF REFERENCE NUMBERS

(16) 1 rotor spinning machine 2 workstation 3 yarn 4 package 5 spinning rotor 6 bearing 7 control system 8 rotor cup 9 rotor shaft 10 drive 11 bearing element 12 axial bearing 13 sensor 14 article management system