DE102021002523B4 - Device and method for winding and twisting fiber material in ring spinning or ring twisting machines - Google Patents

Abstract

Device for winding and twisting fiber material in ring spinning or ring twisting machines with stators, which have at least one high-temperature superconducting material and a stator cooling system, as well as ring-shaped magnetic field-generating rotors coaxially associated with the rotatable spindles, which together with a connected rotor for guiding and winding the thread on the respective Serve the spindle, characterized in that at least two high-temperature superconducting stators (1) together with their thermally connected cooling devices are arranged without contact and parallel to one another along the course of the row of spindles and in the magnetic field of the continuous intermediate space between the respective adjacent stators (1) which are coaxial to the spindle ( 3) aligned magnetic field generating rotors (2) are introduced magnetically floating.

Description

The invention relates to a device and a method that can be used by means of this device, which are used for winding and twisting yarns in particular in ring spinning and ring twisting machines. The solution created uses arrangements of high-temperature superconducting magnetic bearings to prevent the yarn from being burned at high speeds by the rotation of the permanent-magnetic rotors arranged coaxially to the spindles.

Ring spinning technology is the oldest type of fiber spinning and is still in use. However, due to the high quality of the yarn and its flexibility, the ring spinning process is the dominant technique in yarn production. The ring spinning process is in use worldwide with a number of advantages that are hardly matched by others

1. (i) Herstellung von sowohl feinfädigen als auch hochfesten Garnen;
2. (ii) universelle Anwendung auf eine große Vielfalt sowie auf sehr spezielle Garne;
3. (iii) Ringspinnen ist flexibel in Bezug auf Mengen, Garnqualität und Gleichmäßigkeit;

techniques can be substituted. Basic advantages are:

1. (i) manufacture of both fine filament and high tenacity yarns;
2. (ii) universal application to a wide variety as well as to very specific yarns;
3. (iii) ring spinning is flexible in terms of quantities, yarn quality and uniformity;

Ring spinning can perform the widest range of yarn counts with the highest strength and quality. In contrast, ring spinning is slower than other modern spinning systems such as rotor, friction, jet or vortex spinning and requires more processing steps. The production limitation and productivity is determined by the conventional ring rotor system, which at higher speeds causes mechanical friction in connection with heating of the rotor or yarn guide. As a result, the yarn is burned, burns through and tears.

Is known after CH 396 714 A a ring device by means of which the production efficiency can be increased without using a mechanism affecting the high spindle speed. This ring device is of a simple construction which does not require a traveler-type element which, by contact with other parts, generates friction and subjects the yarn to excessive tension, and also requires lubricating operations. For this purpose, the ring device has a ring which is held in a state of levitation in the space present within an annular ring holder by means of magnetic force. There is an annular air gap between the ring and the ring holder, which the roving must pass through. The ring and the ring holder can be designed as permanent magnets. The disadvantage of this solution, however, is the limited use of the ring traveler system at higher spindle speeds. The limitation of traveler speed means that the performance of ring spinning and ring twisting machines cannot be improved.

Also known after U.S. 5,109,659 A a magnetic ring and method for spinning textile yarn. In this solution, textile yarn is passed under a permanent magnet ring to a driven spool, with a fixed ring supported on a ring rail and an extension projecting inward under the permanent magnet ring providing a physical enclosure around the permanent magnet ring, the a having complementary peripheral surface. The fixed ring provides a repulsive magnetic force that causes the permanent magnetic ring to levitate in a maintained centered relationship therein. The fixed ring can consist of either permanent magnets held in stacked relationship by removable clips, or electromagnets connected by a hinge. Also with this solution an increase in the speed of the spindles is limited by occurring friction.

Shortly after the discovery of the high-temperature superconductors (HTS) in 1986/87, the combination of a permanent magnet (PM) with the new superconductors was proposed, demonstrating almost friction-free levitation and rotation. The SMB technology for use in centrifuges was later described in the literature as early as 2001. It could be shown that the new type of magnetic bearing enables extremely high revolutions per minute (rpm) of over 10 ⁵ . The advantages and benefits of the HTS magnetic bearings are useful for many applications, especially in high-tech solutions.

Due to the almost friction-free operation, high speeds without lubrication, no abrasion and no particle formation are possible even under difficult environmental conditions such as heat, cold, steam, vacuum and aggressive chemicals.

At the same time, one learned to understand the rotor dynamics with self-regulating imbalance compensation, overcoming critical speeds in high-speed operation and increasing rotor speeds, as well as the shifting of superconducting magnetic bearings (SMB) into the load range of tons, such as when used in flywheel energy storage systems.

First experiments and applications of the SMB in ring spinning technology started in 2010. Later, the Dresden group of Hussain, de Haas and Schultz investigated in detail the significant advantages of replacing the conventional ring spinning method with the use of a rotating SMB. The SMB design followed the coaxial PM ring-to-HTS ring design integrated into a stainless steel vacuum cryostat. A disadvantage is the great effort involved in the superconductor ring geometry.

From the prior art by the WO 2010/070 562 A2 discloses a device for supporting and rotating a disk-like object, consisting of a first rotor comprising a support for supporting the disk-like object, the first rotor being located in a process chamber. A second rotor connected to a drive mechanism for rotating the second rotor, the second rotor being coupled to the first rotor by magnetic forces without contacting the first rotor. The second rotor is located outside of the process chamber. Disposed between the first rotor and the second rotor is a wall and at least one magnetic pair, the pair including a first coupling portion and a second coupling portion. The first clutch part comprises a clutch magnet (eg permanent magnet) mounted on the first rotor and the second clutch part comprises a high temperature superconducting material (HTS). The magnetic pair(s) are arranged and/or shaped such that no degree of freedom is left between the first rotor and the second rotor, so that the first rotor moves together with the second rotor. An application of this solution to ring spinning or ring twisting machines would require a high level of technical complexity. In addition, the arrangements of the device components are unsuitable for realizing the required maximum speeds of the spindles.

From the WO 2012/100 964 A2 and the WO 2017/178196 A1 winding and ring twisting devices of a ring spinning or ring twisting machine are known. In these devices, the friction between ring and rotor is eliminated by magnetic levitation, which reduces the acting frictional forces. An annular stator made of a superconducting material is used with a corresponding stator cooling device. In addition to the ring-shaped stator, a ring-shaped permanent-magnetic rotor is used, which is rotatable relative to the stator and is arranged coaxially around the spindle with an eyelet-shaped thread guide element. An annular axial gap is formed between the stator and the rotor. When the superconducting material of the stator is cooled below the transition temperature, the magnetic flux of the rotor is coupled into the cooled stator and is magnetically trapped. Due to this coupling, the rotor is inherently stable above or within the stator. The thread is guided through the axial gap between the stator and rotor from the outside around the rotor and wound onto the spool. The stator and the rotor have particularly rounded shapes so that the thread does not find any edges that impede the circulation of the thread in the gap. Prior to the magnetization and cooling of the HTS stator, a mechanical support is used to ensure the optimized working position. The non-contact bearing of the rotating rotor eliminates the classic RingRotor system, which generates frictional heat, as a productivity-limiting component. Advantageously, the entire rotor with the thread-guiding element is now made to rotate rapidly, which is essentially friction-free apart from a small amount of magnetic friction and thus allows significantly higher spindle speeds.

However, the rotor, which is designed as a magnetic ring, has a considerable weight that must also be accelerated when the spindle is started. In addition, the freely floating magnetic ring cannot be encapsulated, so that the rotor, which runs at high speeds of approx. 20,000 to 30,000 revolutions per minute (rpm), poses a safety risk for the operator of the system. Finally, the thread guide element on the magnetic ring rotor represents an imbalance that becomes more and more problematic as the spindle speed increases due to vibration.

With the WO 2019/037 836 A1 discloses a superconducting magnetic bearing as a support system between two relatively moving parts. One of the parts includes a superconducting unit including at least one superconducting element and a cryostat with a housing. The at least one superconducting element is located inside the housing of the cryostat. The other part comprises at least one element that generates a magnetic field. The at least one superconducting unit and the magnetic field generating element are arranged such that one of the superconducting units and the magnetic field generating element can be supported without contact by interaction of the superconducting element and a magnetic field generated by the magnetic field generating element. At least one electrically conductive layer is arranged as an eddy current damper between the at least one superconducting element and the magnetic field generating element in order to dampen vibrations and to reduce heat generation in the superconducting element. In addition to the required high level of technical effort, the rising trend in heat development remains too high for high-speed operation of the rotor.

The object of the invention is therefore to create a device and a method for winding and twisting fibrous material in ring spinning and ring twisting machines, with which the operating speed of the machines is significantly increased, higher productivity is achieved in ring spinning and the time and material expenditure for assembly and service of the device can be lowered.

This object is achieved by the descriptive features of the device according to patent claim 1. Advantageous developments of the device are characterized by the features of patent claims 2 to 12. The created method describes the features of patent claim 13. An efficient embodiment of the method is claimed by patent claim 14.

With the solution according to the invention, a superconducting magnetic bearing (SMB) is proposed, which comprises a permanent magnet (PM) ring as a rotor, which levitates without contact but stably over a superconductor as a stator with cooling. The respective rotor is arranged coaxially to the associated spindle and the thread to be wound up is made to circulate in the gap between the rotor and the stator. An efficient and variably adaptable design of the device is achieved by arranging at least two high-temperature superconducting stators together with their thermally connected cooling devices without contact and parallel to one another along the course of the row of spindles and in the magnetic field of the continuous space between the respective adjacent stators that are aligned coaxially to the spindle Magnetic field generating rotors are introduced magnetically floating. An additional increase in the stabilization of the position in the magnetic bearing is achieved if the rotors that generate the magnetic field are provided with ferromagnetic magnetic flux collectors, which serve to increase the field strength and guide the magnetic field towards the high-temperature superconductor. A cost reduction for the material expenditure is advantageously achieved if the high-temperature superconducting stators each consist of at least two HTS bulk elements, which are formed separately from one another in sections along the length of the stators and are assigned to the respective rotors that generate the magnetic field.

For simple and time-saving assembly, it is advantageous if the high-temperature superconducting stators consist of material joined together in layers and are designed in the form of strips or cables in terms of their length. Effectively, a simple and material-saving construction of the device is achieved by forming the high-temperature superconducting stators from a thermally insulated tube-in-tube configuration, in which the inner "cold" tube connected to the HTS stator has a temperature below that of the superconducting critical temperature and the outer tube assumes the ambient room temperature. The design of the device for the application of high operating speeds proves to be favorable if the outer tube is formed from a material which has a high electrical conductivity suitable for generating eddy currents and thereby causes additional magnetic stabilization during rotary spinning and twisting operations. A stable magnetic bearing of the rotors at a simultaneously low cost is advantageously achieved by the stators each consisting of a YBaCuO crystal of the composition Y ₁ Ba ₂ Cu ₃ O _x (Y123) or a single crystal of the REBaCuO group of the composition RE ₁ Ba ₂ Cu ₃ O _x (RE rare earths) and the superconductor of the bismuth family BiSrCaCuO are formed.

With the present invention, technical and economic improvements in the machines are achieved through the use of new linear, such as superconducting HTS bulk stator assemblies. The device according to the invention allows almost smooth high-speed operation of the rotors. This is achieved through the greatly simplified stator suspension and the possibility of simultaneous cooling of all stators involved.

The solution created paves the way for a modular design and collective cooling using liquid nitrogen LN2. In addition, the HTS material and machine costs are significantly reduced.

• 1: die schematische Vergleichsdarstellung der bisherigen zur neuen Magnetlagerung der Rotoren,
• 2: die perspektivische Darstellung der Magnetlagerung mit drei Statoren,
• 3: die Querschnittsdarstellung der Magnetlagerung mit drei Statoren,
• 4: die perspektivische Darstellung der Magnetlagerung mit zwei Statoren,
• 5: die Querschnittsdarstellung der Magnetlagerung mit zwei Statoren,
• 6: der schematische Innenaufbau des Stators,
• 7: die prinzipielle Darstellung der zusätzlichen Stabilisierung des Rotors und
• 8: die Umfassungsbandage des Rotors zwecks Ausgleich der dynamischen Kräfte.

The invention will be explained in more detail below using an exemplary embodiment. In the reproductions of the drawing show this explanatory

• 1 : the schematic comparison of the previous to the new magnetic bearing of the rotors,
• 2 : the perspective view of the magnetic bearing with three stators,
• 3 : the cross-section of the magnetic bearing with three stators,
• 4 : the perspective view of the magnetic bearing with two stators,
• 5 : the cross-section of the magnetic bearing with two stators,
• 6 : the schematic internal structure of the stator,
• 7 : the basic representation of the additional stabilization of the rotor and
• 8th : the enclosing bandage of the rotor in order to balance the dynamic forces.

With the 1 A schematic comparison is given between conventional ring singles yarn twisting (a) and the HTS high speed ring spinning process using a magnetically suspended winding ring and traveler design (b). For this purpose, the spindles 3 are magnetically mounted together with the yarn wound into coils 5 between two parallel high-temperature superconductor stators 1 . Ring-shaped, magnetically supported rotors 2 that generate a magnetic field are used in both arrangements. The yarn to be wound is fed by the feed system 16 of the machine. The difference between the two solutions is the design of the magnetic bearing and the cooling system required for the high-temperature superconductor. Conventionally, the HTS magnetic bearing is arranged coaxially with each spindle 3 and the cooling system is adapted to each individual bearing in a complex manner. With the magnetic bearing according to the invention, on the other hand, the magnetic bearing takes place between two adjacent HTS stators that extend along the row of spindles. The required cooling system is designed in such a way that simultaneous cooling of all stators is made possible in a simple manner.

In the 2 The perspective view shown shows the superconducting magnetic bearing with three stators 1. The rotors 2 are designed as permanent magnetic rings with an integrated rotor (eg eyelets). The stators 1 provided with high-temperature superconductors (HTS) run parallel to one another and along the row of spindles. In the space between two adjacent stators 1, the rotors 2 are magnetically mounted. Furthermore, there is the possibility of arranging additional stators 1 in parallel as required. A smaller tube 8 with HTS superconductors arranged on it is introduced inside the stators 1 designed as a tube 9 . These superconducting materials 4 are applied in sections along the longitudinal extent of the tube 8 in such a way that they bring about the intended position of the respective rotor 2 . The solution created is adapted to the conventional ring spinning machines in structure and design. Due to the linear structure, the innovation follows the traditional ring spinning machine design and eliminates the need for major ring spinning machine modifications when replacing conventional ring traveler devices with superconducting magnetic bearings (SMB) in series. The system works contact-free and has extremely low rotational friction.

Due to the free suspension of the rotor combination above the HTS stator 1 and its rotation at almost spindle speed, the frictional heat of the rotor 2 can be significantly eliminated even if the rotor speed is further increased. In the dynamic process, only a small amount of friction is generated between the thread and the runner. The generated rotation of the rotor 2 significantly reduces the thread-traveller frictional interaction, as a result of which a large part of the heat source is switched off. The rotor 2 and the stator 1 are designed in such a way that a circular air gap is formed between the rotor 2 and the stator 1 at an axial distance and coaxial to the spindle 3 . The thread is fed through the rotating runner and can be wound onto the rotating bobbin. In contrast to previous bearing solutions, where adjacent spindles 3 run at room temperature conditions in the passage of a cryostat, in the new solution the spindles 3 are not separated and have an open space along the row of spindles. With this construction, common LN2 cooling of a number of respective stators 1 becomes possible with a large clearance. Furthermore, spindles 3 and coils can be serviced or replaced much more easily in this way.

With 3 the schematic cross-sectional structure of the magnetic bearing formed from three stators 1 is reproduced. The arrangement of the inner tubes 8 in the respective outer tube 9 can be seen. The rotors 2 with the respectively associated spindles 3 are magnetically suspended in the space between two adjacent stators 1 in each case. The simultaneous cooling of all superconductors between the tubes (8; 9) is carried out by cooling with liquid nitrogen (LN2).

The representation of 4 shows the perspective view of a magnetic bearing consisting of two stators 1 . In this embodiment, too, the HTS superconductors 4 are applied in sections along the longitudinal course of the stators 1 on the inner tube 8 and positioned in such a way that they bring about the position to be assumed by the spindles 3 magnetically. In addition, the possibility is also provided of designing the HTS superconductor 4 in the form of a strip or cable, which is applied to the inner tube 8 over the entire length of the stator 1 during assembly. At the respective intended magnetic bearing points of the rotor 2, the HTS superconductor, which is usually built up in layers, is already adapted to the magnet strengths to be produced during prefabrication.

A cross-sectional view of the magnetic bearing formed from two stators 1 can be seen in FIG 5 be removed. In addition to the bearings of the rotor 2 already described, the cooling lines 15 leading into and out of the interior of the stators 1 can be seen from the schematic representation.

The structural internal structure of the stator 1 is from the pictorial representation of 6 apparent. The square outer tube 9 represents the vacuum chamber for the inner tube 8 , which is also square. The HTS superconductor 4 is glued to the inner cold tube 8 . Liquid nitrogen is introduced into the inner tube 8 as a coolant. The inner tube 8 connected to the HTS superconductor 4 is mechanically fixed by spacer assemblies 10 made of glass fiber structures. This largely prevents a thermally conductive connection between the “cold” inner tube 8 and the outer tube 9, which is adapted to the room temperature. Since the beams are made of a light Al alloy, the design can be made very compact and light in weight. In addition, a high thermal connection between the inner tube 8 and the HTS superconductor 4 is achieved by the AL alloy material of the cryostat. However, the high thermal expansion coefficient of the Al alloy at room temperature must be taken into account when determining and fixing the exact longitudinal position of the superconducting stators 1 in the 4-5 m long support elements.

The basic representation of an additional stabilization of the position of the rotor 2 is over 7 apparent. In addition to the levitation of the thread-guiding ring-shaped rotor 2 , an additional stabilization is provided by electrical eddy currents 17 , which are induced in the cryostat and the stators 1 . The inner and outer tubes are made of an electrically conductive aluminum alloy. As a result, the rotating rotor 2 will float above a metallic Al sheet. As a result, two effects can contribute to the stabilization of the rotating rotor 2 . According to Lenz's law, the direction of any magnetic induction effect is such that it acts opposite to the cause of the effect. Thus, the direction of the magnetic force on the moving magnet is opposite to its motion. The induced current attempts to maintain the current status quo by counteracting movement or a change in flow. Above the stators 1 there is a lift force in the direction normal to the conductive plane and a drag force opposite to the direction of rotation. Accordingly, both forces contribute to additional holding and stabilization of the rotating rotor 2 during winding and twisting. Another embodiment is the generated braking force, which causes rapid deceleration of the rotating rotor 2 by changing the circumferential magnetization of the annular rotor 2 . At low speed, the drag force is proportional to the speed v= w/r and it is greater than the lift force, which is proportional to v ² .

With increasing speed of the rotor 2, the drag force reaches a maximum and decreases with 1/(v) ^1/2 . The lift force that stabilizes the rotor 2, on the other hand, increases with v ² at low speed and overtakes the drag force with increasing speed. The ratio of buoyancy to drag forces is of great practical importance and is given by f _L /f _D = v/vi, where v and v _i are the velocities of the magnetic dipole across the conductive sheet and the corresponding positive and negative image, the propagates downwards with the velocity v _i .

With the graphic of 8th the basic behavior of the rotors 2 in high-speed ring spinning applications is reproduced. In the solution according to the invention for high speeds, the rotational friction and the dynamic effects of the magnetic bearings are of particular importance. In this area, the fundamental advantages of superconducting bearings over conventional bearings are significant. The superconducting passive-magnetic bearings exhibit significantly lower friction than conventional roller bearings, at least by a factor of four decades. Even compared to pressurized air bearings, the friction of the passive-magnetic HTS bearings is in the per thousand range and is therefore exceptionally low. This extremely low friction is the physical basis for the innovative ring spinning technology up to the highest spindle speeds.

Another critical point of the ring rotor dynamics are the centrifugal forces. In the present invention, the focus is on rotational speeds of the permanent-magnetic rotor 2 with the yarn guide of up to 50,000 rpm. A rotor 2 measuring 60 mm × 40 mm × 10 mm, which serves as a twisting and rotating element, suffers from the enormous centrifugal forces that can destroy the working ring. In a first approach, one should consider the maximum tensile force or force density through the tangential vector at the inner radius r _i . $${\mathrm{\sigma }}_{\text{t}}=\mathrm{<figure-callout\; id="2"\; label="\rho \; v"\; filenames="DE102021002523B4\_0002.png,DE102021002523B4\_0003.png"\; state="\{\{state\}\}">\rho </figure-callout>}{\text{v}}^{}{}^2=\mathrm{<figure-callout\; id="2"\; label="\rho \; \omega "\; filenames="DE102021002523B4\_0002.png,DE102021002523B4\_0003.png"\; state="\{\{state\}\}">\rho </figure-callout>}{\mathrm{\omega }}^{}{\mathrm{}}^2{\text{right}}^2$$

When the ring-shaped rotor 2 rotates, different centrifugal forces arise that can destroy the rotor 2 . The highest mechanical forces occur at the inner radius of a rotating ring. The tensile strength value of sintered NdFeB is about 80 - 90 MPa (12,000 psi). However, at a rotation speed of 50 000 rpm around the spindles, a 60 × 40 × 10 NdFeB PM ring suffers a maximum tangential force density of ~185 MPa, more than a factor of two of the material's intrinsic tensile strength. Accordingly, the dynamic forces must be compensated by a corresponding enclosing bandage 18 in the circumferential direction of the rotor 2 .

The bandage ring 18 should be made of materials with high tensile strength, either metallic such as non-magnetic stainless steel, high-strength Al or Mg alloys, or a non-metallic ring made of glass or carbon fiber compounds. In the best and most optimal case, the safety ring reinforcement provides a pre-pressure on the rotor 2 already at zero speed and then prevents any cracks or defects of the NdFeB magnet ring under the nominal operating speeds. A safety ring thickness of 3 mm Al alloy AL7075 was selected as a practical solution and firmly connected to the rotor 2 by thermal shrinking.

Reference List

1

stator

2

rotor

3

spindle

4

HTS superconductor

5

Kitchen sink

6

yarn

7

runner

8th

inner tube

9

outer tube

10

spacer assembly

11

punctiform support

12

punctiform support

13

bandage

14

Working gas N2

15

cooling lines

16

feeding system

17

Electrical eddy current

18

bandage

Claims (14)

Device for winding and twisting fiber material in ring spinning or ring twisting machines with stators, which have at least one high-temperature superconducting material and a stator cooling system, as well as ring-shaped magnetic field-generating rotors coaxially associated with the rotatable spindles, which together with a connected rotor for guiding and winding the thread on the respective spindle, characterized in that at least two high-temperature superconducting stators (1) together with their thermally connected cooling devices are arranged without contact and parallel to one another along the course of the row of spindles and in the magnetic field of the continuous intermediate space between the respective adjacent stators (1) which are coaxial to the spindle ( 3) aligned magnetic field generating rotors (2) are introduced magnetically floating. device after claim 1 , characterized in that the magnetic field generating rotors (2) are provided with ferromagnetic magnetic flux collectors, which are used to increase the field strength and guide the magnetic field to the high-temperature superconductor (4). device after claim 1 , characterized in that the high-temperature superconducting stators (1) each consist of at least two HTS bulk elements, which are formed separately from one another in sections and are assigned to the respective rotors (2) that generate a magnetic field. device after claim 1 , characterized in that the high-temperature superconducting stators (1) consist of material assembled in layers and are designed in the form of strips or cables in their length extension. device after claim 1 , characterized in that the high-temperature superconducting stators are formed from a thermally insulated tube-in-tube configuration in which the inner "cold" tube (8) connected to the HTS stator (1) has a temperature below the superconducting critical Temperature is and the outer tube (9) assumes the ambient room temperature. Device according to claims 1 and 5 , characterized in that the outer tube (9) is formed from a material which has a high electrical conductivity suitable for generating eddy currents and thereby brings about additional magnetic stabilization during rotary spinning and twisting operations. device after claim 1 , characterized in that the stators (1) each consist of a YBaCuO crystal of the composition Y _i Ba ₂ Cu ₃ O _x (Y123) or a single crystal of the REBaCuO group of the composition RE ₁ Ba ₂ Cu ₃ O _x (RE rare earth) and the superconductor of the bismuth family BiSrCaCuO. device after claim 1 , characterized in that the stators (1) each consist of a plurality of single crystals lined up or grown together. device after claim 1 , characterized in that the magnetic field generating rotors (2) each have a surrounding bandage (13) for the purpose of compensating their centrifugal forces, which consists of a material with high tensile strength. device after claim 1 , characterized in that in the stator-cryostat arrangement, for the purpose of additional stabilization, an electrodynamically supported levitation is effected by means of a material with a high electrical conductivity and due to an eddy current generation in the metallic surface of the cryostat. Device according to claims 1 and 5 , characterized in that the inner tube (8) is cooled by supplying liquid nitrogen and between the inner and outer tube (8; 9) a thermal vacuum insulation and by punctiform supports (11; 12) from between the tubes (8; 9 ) introduced mechanical spacer assemblies (10) thermal heat conduction between the inner and outer tube (8; 9) is prevented. Device according to claims 1 and 5 , characterized in that the inner tube (8) is cooled by connection to a cryocooler. A method for winding and twisting fiber material in ring spinning or ring twisting machines, in which the permanent magnetic rings serving as rotors are stored in high-temperature superconductor magnetic bearings, characterized in that a device according to one of patent claims 1 until 12 is provided, and that the rotors (2) coaxially assigned to the spindles (3) are magnetically suspended within a continuous intermediate space between two stators (1) connected to cryostats and arranged parallel and without contact along the row of spindles, with the 1) connected cryostats that also extend along the row of spindles, a simultaneous cooling of all stators (1) is carried out. procedure after Claim 13 , characterized in that the stators (1) are cooled by the supply of liquid nitrogen via the inner tube (8) extending along the row of spindles of a tube-in-tube connection of the cryostat, the thermal insulation between the inner and outer tube (8;9) is carried out by vacuum insulation and the returned "cold" working gas N2 (14) is condensed and liquefied by means of continuous mechanical recooling and fed back into the cooling circuit.

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