CN111102290B

CN111102290B - Safety bearing for a rotor shaft of a textile rotor and bearing arrangement

Info

Publication number: CN111102290B
Application number: CN201911023823.5A
Authority: CN
Inventors: M·劳尔; M·莫拉维; M·库布勒; B·洛斯; 安德里亚斯·约瑟夫·普罗尔; P·迪恩贝格尔; 康斯坦汀·里格; V·克鲁森
Original assignee: Maschinenfabrik Rieter AG
Current assignee: Maschinenfabrik Rieter AG
Priority date: 2018-10-29
Filing date: 2019-10-25
Publication date: 2023-12-19
Anticipated expiration: 2039-10-25
Also published as: CN111102290A; DE102019127837A1

Abstract

Safety bearing (10, 12) for a rotor shaft (3) of a textile rotor (2), which is supported in a magnetic bearing (6), having a bearing element (8) made of a wear-resistant material, which is designed to cooperate with a bearing surface (5, 15) of the textile rotor (2), comprising a damping element (9), in which the bearing element (8) is accommodated. Bearing arrangement for a rotor shaft (3) of a textile rotor (2), which is supported in a magnetic bearing (6), having a bearing housing (16), a front safety bearing (10) and a rear safety bearing (12), having at least one safety bearing (10, 12) as described.

Description

Safety bearing for a rotor shaft of a textile rotor and bearing arrangement

Technical Field

The invention relates to a safety bearing for a rotor shaft of a textile rotor, which is supported in a magnetic bearing, having a bearing element made of a wear-resistant material, which is designed to cooperate with a bearing surface of the textile rotor. The invention further relates to a bearing arrangement for a rotor shaft of a textile rotor, which is supported in a magnetic bearing, having a bearing housing, a front safety bearing and a rear safety bearing.

Background

The textile rotors of today's open-ended textile machines are usually supported in magnetic bearings due to the high rotational speeds well above 100,000 1/min. These magnetic bearings are advantageous at very high rotational speeds compared to purely mechanical bearings, since they have low friction losses and are hardly subject to losses. They can be implemented both as passive bearings with permanent magnets and as active bearings with controlled electromagnets. If passive magnetic bearings are used in an open textile device, they are typically used for radial bearings. In order to maintain the textile rotor also in the axial direction in a predetermined operating position, the axial position of the rotor is continuously controlled by the control device. In contrast, in actively controlled magnetic bearings, depending on the embodiment, the radial position or the axial position of the textile rotor or both positions are permanently detected and correspondingly controlled by the control device. In order to avoid damage to the magnetic bearings and the components of the drive in the presence of power disturbances, when vibrations occur or when unbalance of the textile rotor increases and during starting and stopping, mechanical safety bearings are provided.

An open textile device is known from DE 198 27 A1, which has a textile rotor supported in a magnetic bearing and two mechanical safety bearings, which show radial end stops for the rotor shaft. The safety bearing is embodied as a bearing ring which is fixed in a holder which is connected to the bearing housing. Additionally, an axial safety bearing is provided, which is formed by a support ball, the distance of which from the rear end of the rotor shaft can be adjusted.

Such bearing rings are usually made of a material with good emergency running properties, such as a plastic material or a bearing metal. In many cases, for example in the event of a control failure or in the event of resonance, the rotor shaft falls into the safety bearing without slowing down, which can lead to damage to the safety bearing or a reduction in the service life.

Disclosure of Invention

The object of the present invention is therefore to provide a safety bearing which has an improved service life. Furthermore, a corresponding bearing arrangement should be provided, which has such a safety bearing.

This object is achieved by the features of the independent claims.

A safety bearing for a rotor shaft of a textile rotor is designed to cooperate with a bearing surface of the textile rotor, which is supported in a magnetic bearing, which has bearing elements made of a wear-resistant material.

It is proposed that the safety bearing comprises a damping element in which the bearing element is accommodated. The damping element dampens the impact when the rotor shaft strikes the safety bearing, whereby the emergency running performance of the safety bearing can be used significantly better for carrying and the service life of the safety bearing can be improved. For this purpose, the damping element is made of an elastically deformable material which returns to its original position again after deflection due to an impact. The deformation of the safety bearing or of the actual bearing element due to strong impacts is thereby avoided. At the same time, the safety bearing can however allow a slight axial offset between the axis of the rotor shaft and the bearing axis, which can occur, for example, in the case of problems in the bearing controller or the magnetic bearing or can be caused by vibrations.

Accordingly, a bearing arrangement for a rotor shaft of a textile rotor is also proposed, which is supported in a magnetic bearing, which bearing arrangement has a bearing housing, a front safety bearing and a rear safety bearing, at least one of which comprises a damping element as described above.

It is particularly advantageous if the bearing element is configured as a bearing ring. The safety bearing can thus advantageously be configured as a radial safety bearing, which surrounds the rotor shaft in an annular manner.

Furthermore, it is advantageous if the damping element is configured as a damping ring. The damping element with the bearing element can thereby be inserted, for example, into a corresponding bore of the holder for the safety bearing and thereby be mounted in a simple manner.

If the bearing element and the damping element are each configured annularly as a bearing ring and a damping ring, they together form a fastening ring which can be installed in the open textile device or in a corresponding holder for the safety bearing as a whole and can be accommodated in the opening of the rotor shaft.

If the safety bearing is configured as an axial safety bearing, the bearing element can also have a shape other than annular, as is the case for damping elements.

Furthermore, it is naturally also possible that only the bearing element is configured as a bearing ring, while the damping element has other shapes. It is only necessary here that the damping element supports the bearing element against a holder for the safety bearing in order to be able to exert its damping effect.

Furthermore, it is advantageous if the damping element is made of a plastic material. Plastic materials such as Polyetheretherketone (PEEK), PEEK with additives, polyoxymethylene (POM) or polyethylene terephthalate (PET) generally have good damping properties and are therefore very suitable for this purpose. However, polyamides (PA), polyurethanes (PUR), polyethylenes (PE) and silicones are also conceivable. In any case, the material of the damping element has a greater elastic deformability than the material of the bearing element, so that the energy upon impact of the rotor shaft on the safety bearing can be absorbed well.

It is particularly advantageous if the damping element is made of a material having an elastic modulus of less than 3000MPa, preferably less than 2000MPa and particularly preferably less than 1000 MPa. These plastic materials with a low modulus of elasticity have good acoustic damping and correspondingly also good mechanical vibration damping. This is necessary in particular in the event of a drop in the textile rotor, for example in the event of a bearing failure, since different critical frequencies are experienced here, which can lead to undesired resonances.

Particularly advantageously, the damping element is made of Polyoxymethylene (POM) having an elastic modulus of less than 800 MPa.

However, it is particularly advantageous in bearing elements made of bronze or brass material. These materials have good emergency running properties and are sufficiently wear-resistant. Furthermore, these materials are not prone to segregation of metal particles upon input of impact energy, which can also lead to the formation of hot sparks. It is particularly advantageous if the bearing element is made of a copper-tin-zinc alloy. This applies in particular to emergency bearings designed as sliding bearings. Alternatively, but also possible, the bearing element is made of PEEK material (polyetheretherketone), in particular of a graphite composition. It is also conceivable for the bearing element to be made of PTFE material or to be coated with PTFE. These materials also have good emergency running properties and, at the same time, already include damping.

In principle, the damping element and the bearing element can be connected to each other in different ways.

However, it is particularly advantageous if the damping element is injection-molded directly onto the bearing element. In this way, a particularly good transmission of vibrations or excitation from the bearing element to the damping element is achieved. The damping element can be entirely surrounded by damping material or embedded therein, whereby a very uniform damping effect can be achieved in all directions. At the same time, the damping element and the bearing element are fixedly connected to one another, so that the bearing element cannot be accidentally released from the damping element or its position within the damping element can be changed. This prevents both incorrect mounting of the safety bearing and damage during operation of the magnetic bearing. Furthermore, the production of the safety bearing can thus be simple and cost-effective. However, it is also conceivable that the damping element and the bearing element are bonded to one another.

However, according to another embodiment, the damping element can also be detachably connected to the bearing element, for example by means of a press connection, a clamping connection, a bayonet connection or a screw connection.

Alternatively, it is proposed that the bearing element is made of ceramic material or comprises ceramic materialIs made of a composite material of (a). Preferably, the ceramic material comprises a material selected from the group consisting of: al (Al) ₂ O ₃ 、ZrO ₂ 、TiO ₂ Or Si (Si) ₃ N ₄ . Ceramic materials are very suitable for the current use purposes with high impact energy due to their good mechanical strength and good wear resistance. Furthermore, they reduce the risk of damaging the rotor shaft and the bearing elements due to their good sliding properties and high temperature resistance. Another advantageous feature of the ceramic material is a high wear resistance even at high temperatures, which also increases the service life of the ring. The embodiment of the bearing element made of ceramic material is thus also of independent inventive significance.

According to an advantageous development, the bearing element contains particles of a lubricating material, in particular nickel or graphite. Nickel is advantageous in particular in ceramic materials or in composite materials comprising ceramic materials. The lubricating material prevents the formation of metallic particles, which can lead to the formation of sparks, when the rotor shaft is strongly impacted by the ceramic material. However, graphite can be advantageously used for bearing elements made of plastic materials such as PEEK.

Advantageously, the bearing element made of ceramic material is also surrounded by the damping element as described above. However, it is also possible for the bearing element to be accommodated directly (i.e. without damping elements) in the holder of the bearing housing.

In such a bearing element made of ceramic material, it is furthermore advantageous if it has a relatively high, ra 1.6 or higher surface roughness, which prevents the so-called "dry friction backspin effect (dry friction backward whirl effect)". The same or similar results are achieved by: the inner opening of the ceramic ring is interrupted by at least one groove extending from one side of the ceramic ring to the other.

Furthermore, it is advantageous if the safety bearing has a fastening device for detachable fastening to the bearing housing of the magnetic bearing, in particular to the holder of the bearing housing. In the simplest case, the fastening means can comprise an active surface, in particular an outer circumferential surface, for connection to the bearing housing by means of a press connection. Such an embodiment can be produced simply and cost-effectively. However, it is also conceivable that the fastening means comprise part of a screw thread of the bayonet closure or clamping means.

If the bearing element is surrounded by a damping element, it is advantageous if the fastening means are provided on the damping element. The bearing element is thus fastened to the bearing housing by means of the damping element.

According to a particularly advantageous embodiment, the damping element, in particular the damping ring, has a fastening hole for detachable fastening to the bearing housing. Preferably, the fastening hole is provided in the annular abutment surface of the damping element. The safety bearing or the damping ring with the bearing ring can thereby be screwed onto the bearing housing from the outside on the end side in a simple manner. This allows easy replacement, if necessary.

Furthermore, it is advantageous if the safety bearing has a centering device. By means of the centering device, the safety bearing can be arranged precisely centered with respect to the axis of the magnetic bearing when fastened in the bearing housing. The centering device can comprise a centering surface, for example a centering diameter on a centering pin. This then cooperates with the centering surface of the bearing housing or of the holder of the bearing housing, in particular the centering hole. Thereby, the rotor shaft is also positioned with respect to the magnetic bearing by the safety shaft in the loaded inactive state (starting position).

In the case of a bearing arrangement, it is accordingly advantageous if the front safety bearing is fastened, in particular screwed, directly to the bearing housing, in particular to the front wall of the bearing housing.

Furthermore, in the bearing arrangement, it is advantageous if the rear safety bearing is fastened, in particular screwed, to the rear wall of the bearing housing, in particular to a bearing cap, which is arranged on the rear wall.

Thereby, it is not necessary to provide an additional retainer for the safety bearing on the bearing housing.

In the case of a damping element, in particular a damping ring, it is furthermore advantageous if it is embodied in two parts with an inner damping element and an outer damping element. The inner damping element and the outer damping element can be made of materials having different damping properties and/or different elastic properties.

Drawings

Other advantages of the present invention are described in the following examples. The drawings show:

fig. 1 shows a schematic cross-sectional side view of an open textile device with a textile rotor supported in a magnetic bearing and a bearing device with a safety bearing;

fig. 2 shows a schematic cross-sectional side view of a bearing arrangement with a front safety bearing and a rear safety bearing;

fig. 3 shows a front safety bearing for a rotor shaft according to a first embodiment in a front view;

FIG. 4 shows the safety bearing of FIG. 3 in a cross-sectional side view;

FIG. 5 shows a rear safety bearing for a rotor shaft in a front view;

FIG. 6 shows a rear safety bearing for a rotor shaft in a cross-sectional side view;

fig. 7 shows a front safety bearing for a rotor shaft according to a second embodiment in a sectional perspective view;

FIG. 8 shows a front safety bearing for a rotor shaft according to a third embodiment in a sectional perspective view;

fig. 9 shows a front safety bearing for a rotor shaft according to a fourth embodiment in a sectional perspective view;

FIG. 10 shows a front safety bearing for a rotor shaft according to a fifth embodiment in a cross-sectional side view;

FIG. 11 shows a front safety bearing for a rotor shaft according to a sixth embodiment in a sectional perspective view, and

fig. 12 shows a further embodiment of a rear safety bearing for a rotor shaft in a sectional side view.

List of drawing identifiers

1. Open type textile device

2. Textile rotor

3. Rotor shaft

4. Rotor cup

5. Axial bearing surface

6. Magnetic bearing

6a front radial bearing

6b rear radial bearing

6c axial bearing

7. Cover element

8. Bearing element

8a bearing ring

9. Damping element

9a damping ring

10. Front safety bearing

11. Shoulder part

12. Rear safety bearing

13. Fastening device

14. Coupling device

15. Radial bearing surface

16. Bearing housing

17. Retainer

18. Driver(s)

19. Fastening hole

20. Bearing gap

21. Surface for sticking

22. Front wall

23. Rear wall

24. Bottom part

25. Extension part

26. Screw thread

27. Bearing cap

28. An opening

29. Bayonet projection

30. Bayonet recess

31. Bayonet stopper

32. Protrusions

33. Annular opening

34. Inner surface

35. Projection part

36. A receiving opening.

Detailed Description

In the following description of the drawings, the same reference numerals are used for the same or at least similar features in the various embodiments or in the various drawings, respectively. Accordingly, some of the features are set forth only when they are first mentioned or only once with reference to the corresponding figures. The arrangement and/or the manner of operation of these features corresponds to the arrangement and manner of operation of the same or similar features described, as long as these features are not individually described in connection with the other figures. Furthermore, where there are multiple identical features or elements in the figures, only one or a few of these identical features are generally labeled for clarity.

Fig. 1 shows an open textile device 1 in a schematic cross-sectional overview. The open textile device 1 can be closed at the front side with a cover element 7. In the open textile device 1 there is a magnetic bearing 6 which is arranged in a bearing housing 16 in which the textile rotor 2 is rotatably supported. The textile rotor 2 is formed in two parts and has a rotor cup 4 and a rotor shaft 3, which are connected by a coupling device 14. By means of the drive 18, the textile rotor 2 can be put into rotation and held. In a conventional manner, the magnetic bearing 6 comprises a front radial bearing 6a, a rear radial bearing 6b and currently a separate axial bearing 6c. However, it is not absolutely necessary to construct the axial bearing 6c separately from the radial bearings 6a, 6 b. It is also possible that the axial bearing is realized by a component of a radial bearing. By means of the magnetic bearing 6, the textile rotor 2 is held in the radial direction and in the axial direction and is thus supported in a floating state, whereby a radial and an axial bearing gap 20 is formed. The magnetic bearing 6 can be implemented as an active magnetic bearing 6 or as a passive magnetic bearing 6. The open textile device 1 further comprises a control device (not shown) by means of which the magnetic bearing 6 can be operated and with which at least a part of the components of the magnetic bearing 6 is brought into a connection suitable for control, depending on the embodiment of the magnetic bearing 6. Currently, both the radial bearings 6a, 6b and the axial bearing 6c of the magnetic bearing are constructed as active magnetic bearings, that is to say the bearing forces are generated by controlled electromagnets and thus require a continuous power supply.

In order to protect the components of the magnetic bearing 6, furthermore, mechanical bearing arrangements are provided in a known manner, which have a front safety bearing 10 and a rear safety bearing 12. The front and rear safety bearings prevent the rotating or stationary parts of the magnetic bearing 6 and parts of the drive 18 from coming into contact with each other in the event of a power failure or in the event of vibrations.

Correspondingly, the textile rotor 2 has a shoulder 11 with a front axial bearing surface 5 which cooperates with a front axial safety bearing 10. For cooperation with the rear axial safety bearing 12, the textile rotor 2 has a rear axial bearing surface 5, which is currently formed by the rear end of the rotor shaft 3.

The front safety bearing 10 is arranged on a holder 17, which is connected to the bearing housing 16. Currently, the retainer 17 is formed directly from the front wall 22 of the bearing housing 16. Currently, the front safety bearing 10 cooperates with the axial bearing surface 5 on the shoulder 11 of the rotor shaft 3 in order to construct the front axial safety bearing 10. Likewise, the front safety bearing 10 cooperates with a radial bearing surface 15 of the rotor shaft 3 in order to construct the front axial safety bearing 10.

The rear safety bearing 12 is also arranged on a holder 17, which is connected to the bearing housing 16, which holder is currently formed by the rear wall 23 of the bearing housing 16. Currently, the rear safety bearing 12 is connected to a bearing cap 27, which is arranged on the rear wall 23. The rear safety bearing 12 (here the damping element 9 of the rear safety bearing 12) has a closed bottom 24. The bottom 24 cooperates with the rear axial bearing surface 5 of the textile rotor 2 and thereby forms an axial rear safety bearing 12. In the radial direction, the rear safety bearing 12 in turn cooperates with a radial bearing surface 15 of the rotor shaft 3.

The front safety bearing 10 and the rear safety bearing 12 together form a bearing arrangement for mechanical protection of the rotor shaft 3 supported in the magnetic bearing 6. However, the embodiment of fig. 1 should be understood as exemplary only. Furthermore, the safety bearings 10, 12 can also be arranged on a separate holder 17. Furthermore, the safety bearings 10, 12 or only one of the two safety bearings 10, 12 can also be configured as radial safety bearings 10, 12 only, and the axial mechanical protection can be performed in other ways. Here, it is also conceivable that the front safety bearing 10 and the rear safety bearing 12 are each identical.

Fig. 2 shows a sectional side view of a further bearing arrangement with a front safety bearing 10 and a rear safety bearing 12. The front safety bearing 10 is arranged on a holder 17 of a bearing housing 16, not shown here, by means of a fastening device 13, which is currently configured as a clamping device. Naturally, a plurality of other fastening means 13 can also be envisaged. The retainer 17 can here again also be formed by the front wall 22 of the bearing housing 16. Thereby, the front safety bearing 10 can be fastened to the bearing housing 16 from the outside in a simple manner and is thus easily accessible. The rear safety bearing 12 is currently designed in annular fashion, but without a closed bottom 24.

Fig. 3 shows a detail view of the front safety bearing 10 in the form of a fastening ring according to the first embodiment. As the bearing element 8, the front safety bearing 10 comprises a bearing ring 8a, which is surrounded by a damping ring 9a as the damping element 9. In operation of the pre-running safety bearing 10, the rotor shaft 3 is guided through the annular opening 33. The inner surface 34 of the annular opening 33 cooperates with the radial bearing surface 15 of the rotor shaft 3. Furthermore, the front safety bearing 10 has an annular abutment surface 21 which cooperates with the axial bearing surface 5 of the shoulder 11 of the rotor shaft 3. From the annular abutment surface 21, a cylindrical projection 35 projects, by means of which the front safety bearing 10 can be inserted into a corresponding receiving opening 36 (see fig. 4). As the fastening means 13, three fastening holes 19 are currently provided. Naturally, it is also possible to provide only two or more than three fastening holes 19.

Fig. 4 shows a sectional side view of the safety bearing 10 of fig. 3, which is now shown inserted in the receiving opening 36. As can be gathered from this figure, the retainer 17 for fastening the safety bearing 10 can have threads 26.

In the front safety bearing 10, as shown in fig. 3 and 4, however, a separate fastening means 13 is not absolutely necessary. It is also conceivable to provide only cylindrical projections 35 as fastening means 13. The diameter of the projection is then at least equal to or slightly greater than the diameter of the receiving opening 36, so that a press connection can be constructed therefrom.

Furthermore, grooves for sealing elements (not shown) in the contact surface 21 can also be provided in such a front safety bearing 10. Thereby, dust entry and fiber fly into the bearing housing 16 can be prevented. The recess can be configured as a circular recess in the contact surface 21 around the entire bearing element 8, and in each case a recess can be provided in the region of the fastening hole 19 around this fastening hole.

Fig. 5 shows a front view of the rear safety bearing 12, which is constructed essentially as the front safety bearing 10 described above. However, unlike the front safety bearing 10 of fig. 3, the rear safety bearing 12 has a closed bottom 24. In operation of the rear safety bearing 12, a bearing gap 20 is also formed between the bottom 24 and the rear axial bearing surface 5. If the magnetic bearing 6 is problematic, the rotor shaft 3 can be supported by the bottom 24. The bottom 24 is shown as continuous in the present case, however, it can also have openings 28 as shown in fig. 6 in order to provide access to the rear end of the rotor shaft 3 and to achieve blowing in of clean air.

As fastening means 13, the current rear safety bearing 12 also has fastening holes 19, which are currently provided in the extension 25 of the damping element 9. Naturally, however, further fastening means 13 can also be provided on the rear safety bearing 12 in order to fasten the latter on its holder 17, on the bearing cover 27 or on the rear wall 23 of the bearing housing 16 (see fig. 1 and 2).

Fig. 6 shows a rear safety bearing 12 similar to that in fig. 5 in a sectional side view. Currently, the rear safety bearing 12 is shown with the rotor shaft 3 accommodated therein, so that the co-action of the axial bearing surface 5 with the bottom 24 can be identified. Currently, the bottom 24 has an opening 28 so that the rear axial bearing surface 5 of the rotor shaft 3 is accessible and clean air can be blown into the bearing gap 20. In this case, it is naturally also possible to provide a plurality of openings 28, which can also be arranged in different positions, which naturally also applies to other embodiments of the safety bearing 12 having the bottom 24.

The safety bearings 10, 12 shown in fig. 3 to 6 preferably comprise a bearing element 8 or a bearing ring 8a, which is made of bronze or brass material. The damping element 9 is embodied as a damping ring 9a and is made of a plastic material. The damping element 9 is preferably injection-molded directly onto the bearing element 8, so that the safety bearings 10, 12 can be produced in an advantageous manner in injection molding technology. The plastic material is preferably polyoxymethylene. In this case, it is particularly advantageous if the fastening means 13 (for example, a clamping means) can be injection-molded directly onto the damping element 9 or can be provided directly in the damping element 9, for example, as fastening holes 19. Likewise, the shaping can be adapted to the specific conditions in the bearing arrangement or the bearing housing 16, for example the extension 25 can be directly injection-molded.

Fig. 7 shows a further embodiment of the front safety bearing 10, wherein the front safety bearing 10 can be fastened in the receiving opening 36 of the holder 17 by means of a bayonet closure as fastening means 13. The receiving opening 36 is here configured in a form for inserting a bayonet closure. The bayonet projections 29 are formed in the bearing element 8 and cooperate with the bayonet recesses 30 and the bayonet stops 31 of the holder 17. The bearing element 8 can be made of bronze material or brass material as described above or, according to an advantageous embodiment, of ceramic material. The ceramic material can also be injection molded directly with the plastic material of the damping element 9.

Fig. 8 shows a further embodiment of a front safety bearing 10 which can also be inserted into a holder 17 by means of a bayonet closure as fastening means 13. In this case, however, the bayonet closure is provided on the damping element 9 and not on the bearing element 8. Furthermore, the damping element 9 has a fastening device 13 for fastening the bearing element 8, which is currently configured as a clamping device.

Fig. 9 shows an alternative embodiment of a front safety bearing 10, which only comprises the bearing element 8. The bearing element 8 is made of ceramic or a composite material comprising ceramic. Which in turn has fastening means 13 (in this case a bayonet closure) to fasten on the holder 17.

Fig. 10 shows a further embodiment of the front safety bearing 10 in a sectional view. The damping element 9 has a first fastening means 13 in the form of a clamping means for inserting the bearing element 8 and a second fastening means 13 in the form of a clamping means for inserting the front safety bearing 10 into a holder 17 (not shown here).

Finally, fig. 11 shows a further embodiment of the front safety bearing 10, in which the damping element 9 or the damping ring 9a is embodied in two parts with an inner damping element 9 and an outer damping element 9. It is thus possible, for example, for the inner damping element 9 to be made of a material with particularly good damping properties, and for the outer damping element 9 to be made of a material which enables good fastening of the front safety bearing 10.

The front safety bearing 10 shown in fig. 7 to 11 is suitable as the front safety bearing 10 in the magnetic bearing 6. The rear safety bearing 12 can be similar to that shown in fig. 5 comprising a bottom 24 and provided with an extension 25 for fastening. Then, a bayonet closure or a clamping closure as fastening means 13 is not necessary. Alternatively, the rear safety bearing 12 can however also be constructed identically to the front safety bearing 10 shown in fig. 7 to 11 or if necessary be provided with a separate axial bearing.

Fig. 12 shows another embodiment of the rear safety bearing 12. The damping element 9 of the rear safety bearing 12 here also has a closed bottom 24, which cooperates with the rear axial bearing surface 5 of the textile rotor 2. In the radial direction, the rear safety bearing 12 in turn cooperates with a radial bearing surface 15 of the rotor shaft 3. The base 24 has a central projection 32, which is embodied as a pin or cast part. The projection 32 can then be configured as a stop for the textile rotor 2 and the rear axial safety bearing 12 in the axial direction. The diameter of the projection 32 is smaller than the diameter of the rotor shaft 3 or the bearing element 8 and, for example, smaller than half the diameter of the bearing element 8, preferably smaller than 20% and particularly preferably smaller than 10%.

In this embodiment, it is advantageous if the relative speed between the rotating rotor shaft 3 and the projections 32 is substantially smaller than in the case of a flat bottom 24 due to the smaller diameter of the projections 32. The embodiment of the projection 32 as a pin is therefore particularly advantageous, so that (ideally) only one point contact takes place between the rotor shaft 3 and the projection.

According to an advantageous first embodiment, the projections 32 can be applied directly at the time of the production of the damping element 9 or directly together with the production of the damping element 9 as a plastic injection-molded part. The safety bearing 12 with the damping element 9 can thus be manufactured very cost-effectively. It is also conceivable to construct the projections 32 by: a bearing plate made of bearing material is fastened to the bottom 24. Advantageously, such bearing plates are injection molded together when manufacturing the damping element 9.

In such a rear safety bearing 12, the bottom 24 can also have one or more openings 28 as described in relation to fig. 5, which openings enable the blowing in of clean air into the rear axial bearing surface 5 of the rotor shaft 3. Currently, the bottom 24 is however shown without the opening 28.

The invention is not limited to the embodiments shown and described. In all the embodiments shown, which have safety bearings 10, 12 with damping elements 9, the bearing element 8 and the damping element 9 can thus also be connected to one another by means of other fastening means, for example by means of an adhesive process, an extrusion process, by means of clamping means, screw connections or the like. It should be noted here that in the bayonet connection and in the press connection, the bearing element 8, the damping element 9 and the retainer 17 can only be used once respectively in the connection system in order to achieve the defined mounting and dismounting. This means that these connections (if they are used, for example, for inserting the safety bearings 10, 12 into the holder 17) must be combined with other connection types for connecting the bearing element 8 and the damping element 9, and vice versa.

As a combination of features, further variants are possible within the framework of the claims, even if they are shown and described in different embodiments.

Claims

1. Safety bearing (10, 12) for a rotor shaft (3) of a textile rotor (2), which is supported in a magnetic bearing (6), with a bearing element (8) made of wear-resistant material, which bearing element is designed to cooperate with a bearing surface (5, 15) of the textile rotor (2), characterized in that the safety bearing (10),

12 Comprising a damping element (9), in which the bearing element (8) is accommodated, the safety bearing (10, 12) having a fastening device (13) for detachable fastening to a bearing housing (16) of the magnetic bearing (6), the fastening device (13) being arranged on the damping element (9), the damping element (9) having a fastening hole (19) for detachable fastening to the bearing housing (16), the fastening hole (19) being arranged in an annular abutment surface (21) of the damping element (9).

2. Safety bearing (10, 12) according to claim 1, characterized in that the bearing element (8) is configured as a bearing ring (8 a).

3. Safety bearing (10, 12) according to claim 1, characterized in that the damping element (9) is configured as a damping ring (9 a).

4. Safety bearing (10, 12) according to claim 1, characterized in that the damping element (9) is made of a plastic material.

5. The safety bearing (10, 12) of claim 4 wherein the plastic material is Polyoxymethylene (POM).

6. The safety bearing (10, 12) of claim 4 wherein the plastic material has an elastic modulus of less than 3000 MPa.

7. The safety bearing (10, 12) of claim 6 wherein the plastic material has an elastic modulus of less than 2000 MPa.

8. The safety bearing (10, 12) of claim 7 wherein the plastic material has an elastic modulus of less than 1000 MPa.

9. Safety bearing (10, 12) according to claim 1, characterized in that the damping element (9) is injection-molded directly onto the bearing element (8).

10. Safety bearing (10, 12) according to claim 1, characterized in that the bearing element (8) is made of bronze material or brass material.

11. The safety bearing (10, 12) of claim 10 wherein the bronze material or brass material is a copper-tin-zinc alloy.

12. Safety bearing (10, 12) according to any of claims 1-10, characterized in that the bearing element (8) is made of a ceramic material or of a composite material comprising a ceramic material.

13. The safety bearing (10, 12) of claim 12 wherein the ceramic material comprises Al ₂ O ₃ Or ZrO ₂ Or TiO ₂ Or Si (Si) ₃ N ₄ 。

14. Safety bearing (10, 12) according to any of claims 1-10, characterized in that the bearing element (8) comprises particles of a lubricating material.

15. The safety bearing (10, 12) of claim 14 wherein the particles of lubricating material are nickel or graphite.

16. Safety bearing (10, 12) according to any of claims 1-10, characterized in that the fastening means (13) comprise a part of a bayonet closure, a screw thread or a clamping means.

17. Safety bearing (10, 12) according to any of claims 1-10, characterized in that the fastening means (13) are arranged to be detachably fastened to a holder (17) of the bearing housing (16).

18. The safety bearing (10, 12) according to any of the preceding claims 1-10, characterized in that the safety bearing (12) has a closed bottom (24), which bottom constitutes an axial safety bearing (12).

19. The safety bearing (10, 12) of claim 18 wherein the bottom (24) has a centered boss.

20. Bearing arrangement for a rotor shaft (3) of a textile rotor (2), which is supported in a magnetic bearing (6), with a bearing housing (16), a front safety bearing (10) and a rear safety bearing (12), characterized in that at least one of the front safety bearing (10) and the rear safety bearing (12) is a safety bearing (10, 12) as claimed in any one of claims 1 to 19.

21. Bearing arrangement according to claim 20, characterized in that the front safety bearing (10) is fastened directly to the bearing housing (16).

22. Bearing arrangement according to claim 21, characterized in that the front safety bearing (10) is screwed directly onto the bearing housing (16).

23. Bearing arrangement according to claim 21, characterized in that the front safety bearing (10) is fastened directly to the front wall (22) of the bearing housing (16).

24. Bearing arrangement according to any of claims 20-23, characterized in that the rear safety bearing (12) is fastened to the rear wall (23) of the bearing housing (16).

25. Bearing arrangement according to claim 24, characterized in that the rear safety bearing (12) is screwed onto the rear wall (23) of the bearing housing (16).

26. Bearing arrangement according to claim 24, characterized in that the rear safety bearing (12) is fastened to a bearing cover (27) arranged on the rear wall (23).