CN111102290A

CN111102290A - Safety bearing for a rotor shaft of a textile rotor and bearing arrangement having a front safety bearing and a rear safety bearing

Info

Publication number: CN111102290A
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: 2020-05-05
Anticipated expiration: 2039-10-25
Also published as: CN111102290B; DE102019127837A1

Abstract

Safety bearing (10, 12) for a rotor shaft (3) of a textile rotor (2) supported in a magnetic bearing (6), having a bearing element (8) made of a wear-resistant material configured for cooperation 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 having a front safety bearing and a rear safety bearing

Technical Field

The invention relates to a safety bearing for a rotor shaft of a textile rotor, which is mounted in a magnetic bearing, having a bearing element made of a wear-resistant material, which is designed to interact 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 mounted in a magnetic bearing, having a bearing housing, a front safety bearing and a rear safety bearing.

Background

The spinning rotors of today's open-end spinning machines are usually supported in magnetic bearings due to the high rotational speeds of well above 100,0001/min. These magnetic bearings are advantageous at very high rotational speeds compared to purely mechanical bearings, since they have low frictional losses and are hardly susceptible 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 open-weave devices, they are typically used for radial bearings. In order to maintain the textile rotor in a predetermined operating position also in the axial direction, the axial position of the rotor is continuously controlled by a control device. In contrast, in actively controlled magnetic bearings, depending on the embodiment, the radial position or the axial position or both positions of the textile rotor are permanently detected and controlled by the control device in each case. In order to avoid damage to the magnetic bearings and the components of the drive in the presence of power supply disturbances, in the event of vibrations or increased unbalance of the textile rotor and in the event of start-up and shut-down, mechanical safety bearings are provided.

An open-end spinning device with a spinning rotor mounted in a magnetic bearing and two mechanical safety bearings which show radial end stops for the rotor shaft is known from DE 19827606 a 1. 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 deceleration, which can lead to damage to the safety bearing or a reduction in the service life.

Disclosure of Invention

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

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

The safety bearing for the rotor shaft of a textile rotor, which is supported in the magnetic bearing, is configured for cooperation with a bearing surface of the textile rotor, 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 damps the impact when the rotor shaft strikes the safety bearing, as a result of which the emergency running behavior of the safety bearing can be used significantly better for load bearing 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. This prevents the safety bearing or the actual bearing element from being deformed by a strong impact. At the same time, the safety bearing can nevertheless allow slight axial offsets 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.

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

It is particularly advantageous if the bearing element is designed as a bearing ring. The safety bearing can thus be advantageously designed as a radial safety bearing, which annularly surrounds the rotor shaft.

Furthermore, it is advantageous if the damping element is designed as a damping ring. The damping element with the bearing element can thus be inserted, for example, into a corresponding bore of a holder for a safety bearing and can thus 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 securing ring which can be installed in the open-end textile device or in a corresponding holder for the safety bearing as a whole and can be received in an opening of the rotor shaft.

If the safety bearing is designed as an axial safety bearing, the bearing element can also have a shape other than annular, which also applies to the damping element.

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

Furthermore, it is advantageous if the damping element is made of a plastic material. Plastic materials such as Polyetheretherketone (PEEK), PEEK with admixtures, 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 when the rotor shaft strikes 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 3000 MPa, preferably less than 2000 MPa 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 when the textile rotor falls, for example when the bearing fails, 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 the case of a bearing element that is made of a bronze material or a brass material. These materials have good emergency running properties and are sufficiently wear resistant. Furthermore, these materials do not readily separate the metal particles upon input of impact energy, which can also lead to the formation of a hot spark. 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 a PEEK material (polyetheretherketone), in particular a PEEK material with a graphite component. It is also conceivable for the bearing element to be made of a PTFE material or to be coated with PTFE. These materials also have good emergency running properties and, at the same time, already include a damping action.

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

However, it is particularly advantageous if the damping element is injection-molded directly on the bearing element. The vibration or excitation thereby achieves a particularly good transmission from the bearing element to the damping element. The damping element can be completely surrounded by the damping material or embedded therein, whereby a very uniform damping action 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 safety bearing can thus be simple and cost-effective to manufacture. However, it is also conceivable for the damping element and the bearing element to be adhesively 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.

It is alternatively proposed that the bearing element is made of a ceramic material or of a composite material containing a ceramic material. Preferably, the ceramic material comprises a material selected from the group consisting of: al (Al)₂O₃、ZrO₂、TiO₂Or Si₃N₄. Due to its good mechanical strength and good wear resistance, ceramic materials are very suitable for the present purpose of use with high impact energy. Furthermore, they reduce the risk of damage to 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 its high wear resistance even at high temperatures, which also increases the service life of the annular element. The embodiment of the bearing element made of ceramic material therefore also has independent inventive significance.

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

Advantageously, the bearing element made of ceramic material is also surrounded by a 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 that it has a relatively high surface roughness of Ra 1.6 or more, which prevents the so-called "dry friction back-rotating 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 detachably fastening to a bearing housing of the magnetic bearing, in particular to a holder of the bearing housing. In the simplest case, the fastening device 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 a part of a thread of a bayonet closure or a clamping means.

If the bearing element is surrounded by the damping element, it is advantageous if the fastening means are arranged 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 arranged in an annular contact surface of the damping element. The safety bearing or the damping ring with the bearing ring can thereby be screwed onto the bearing housing in a simple manner from the outside on the end side. This enables 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 exactly 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 a centering surface, in particular a centering bore, of the bearing housing or of the holder of the bearing housing. Thereby, the rotor shaft is also positioned with respect to the magnetic bearing by the safety shaft in the loading-deactivated state (starting position).

Correspondingly, it is advantageous in the bearing arrangement 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.

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

Thus, it is not necessary to provide an additional holder 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 designed 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 with different damping properties and/or different elastic properties.

Drawings

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

fig. 1 shows a schematic cross-sectional side view of an open-end spinning device with a spinning rotor supported in a magnetic bearing and a bearing arrangement 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 illustrates 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 cut-away perspective view;

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

FIG. 9 shows a front safety bearing for a rotor shaft according to a fourth embodiment in a cut-away perspective view;

fig. 10 shows a front safety bearing for a rotor shaft according to a fifth embodiment in a 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 illustrates another embodiment of a rear safety bearing for a rotor shaft in a cross-sectional side view.

List of reference numerals

1 open type spinning 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

Front 10 safety bearing

11 shoulder part

12 rear safety bearing

13 fastening device

14 coupling device

15 radial bearing surface

16 bearing housing

17 holder

18 driver

19 fastening hole

20 bearing clearance

21 contact surface

22 front wall

23 rear wall

24 bottom

25 extension part

26 screw thread

27 bearing cap

28 opening

29 bayonet projection

30 bayonet recess

31 bayonet stop

32 convex

33 annular opening

34 inner surface

35 projection

36 receive the opening.

Detailed Description

In the following description of the figures, the same reference numerals are used for the same or at least similar features in the various embodiments or in the various figures, respectively. Accordingly, some of the features described are set forth only once in their first mentioned or with reference to the corresponding drawings. As long as these features are not set forth individually in conjunction with further figures, their design and/or mode of action correspond to the same or similar design and mode of action of the described features. Furthermore, where there are a plurality of like features or elements in the drawings, for the sake of clarity, only one or a few of such like features will typically be labeled.

Fig. 1 shows an open weaving device 1 in a schematic sectional overview. The open-end spinning device 1 can be closed off at the front side by means of a cover element 7. In the open-end spinning device 1, there is a magnetic bearing 6, which is arranged in a bearing housing 16 and in which the spinning rotor 2 is rotatably supported. The textile rotor 2 is constructed in two parts with 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 set in rotation and held. In a conventional manner, the magnetic bearing 6 comprises a front radial bearing 6a, a rear radial bearing 6b and, in the present case, a separate axial bearing 6 c. However, it is not absolutely necessary to configure the axial bearing 6c separately from the

radial bearings

6a, 6 b. It is also possible for the axial bearing to be 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 embodied as an active magnetic bearing 6 or as a passive magnetic bearing 6. The open-end spinning device 1 also 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 are brought into a connection suitable for control according to an embodiment of the magnetic bearing 6. Currently, the

radial bearings

6a, 6b and the axial bearing 6c of the magnetic bearings are both 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, a mechanical bearing arrangement is furthermore provided in a known manner, which has 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. In order to cooperate 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 with the bearing housing 16. Currently, the cage 17 is formed directly by 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 and which is currently formed by a rear wall 23 of the bearing housing 16. The rear safety bearing 12 is now 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 the 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 bearing

10, 12 or only one of the two

safety bearings

10, 12 can also be designed as a

radial safety bearing

10, 12 only, and the axial mechanical protection can be implemented in another way. Here, it is also conceivable for the front safety bearing 10 and the rear safety bearing 12 to be embodied identically in each case.

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 in the present case designed as a clamping device. Naturally, a plurality of other fastening means 13 can also be envisaged. The holder 17 can here again be formed by the front wall 22 of the bearing housing 16. The front safety bearing 10 can thereby be fastened in a simple manner from the outside on the bearing housing 16 and is thus easily accessible. The rear safety bearing 12 is currently designed in the form of a ring, but does not have a closed bottom 24.

Fig. 3 shows a detail view of the front safety bearing 10 configured as a fixed 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. During operation of the front 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 contact surface 21, which interacts with the axial bearing surface 5 of the shoulder 11 of the rotor shaft 3. Projecting from the annular contact surface 21 is a cylindrical projection 35, by means of which the front safety bearing 10 can be inserted into a corresponding receiving opening 36 (see fig. 4). As 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 cross-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 holder 17 for fastening the safety bearing 10 can have a thread 26.

In the front safety bearing 10, as shown in fig. 3 and 4, however, a separate fastening device 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 larger than the diameter of the receiving opening 36, so that a press connection can be constructed thereby.

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

Fig. 5 shows a front view of the rear safety bearing 12, which is constructed substantially as described above for the front safety bearing 10. 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 base 24 and the rear axial bearing surface 5. If problems occur with the magnetic bearing 6, the rotor shaft 3 can be supported by the bottom 24. Currently, the bottom 24 is shown as continuous, however, it can also have an opening 28 as shown in fig. 6 in order to provide a passage to the rear end of the rotor shaft 3 and to enable the blowing in of clean air.

As fastening means 13, the rear safety bearing 12 now also has a fastening hole 19, which is now arranged in the extension 25 of the damping element 9. Naturally, however, additional fastening means 13 can also be provided on the rear safety bearing 12 in order to fasten it on its holder 17, the bearing cover 27 or the rear wall 23 (see fig. 1 and 2) of the bearing housing 16.

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 cooperation of the axial bearing surface 5 with the bottom 24 can be recognized. 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. Naturally, a plurality of openings 28 can also be provided here, which can also be arranged at different positions, which naturally also applies to other embodiments of the safety bearing 12 with a 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 a bronze material or a 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 an injection-molding technique. The plastic material is preferably polyoxymethylene. In this case, it is particularly advantageous if the fastening device 13 (for example a clamping device) can be injection-molded directly onto the damping element 9 or can be provided directly in the damping element 9, for example as a fastening hole 19. Likewise, the shaping can be adapted to the specific conditions in the bearing arrangement or 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 the fastening device 13. The receiving opening 36 is configured here in a shape 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 a bronze material or a brass material, as described above, or, according to an advantageous embodiment, of a ceramic material. The ceramic material can also be directly injection-molded 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 the holder 17 by means of a bayonet closure as the fastening device 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, which is in the present case designed as a clamping device, for fastening the bearing element 8.

Fig. 9 shows an alternative embodiment of the front safety bearing 10, which comprises only the bearing element 8. The bearing element 8 is made of ceramic or a composite material containing ceramic. Which in turn has fastening means 13, here 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 device 13 in the form of a clamping device for inserting the bearing element 8 and a second fastening device 13 in the form of a clamping device 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 designed in two parts with an inner damping element 9 and an outer damping element 9. Thereby, it is for example possible that the inner damping element 9 is made of a material having particularly good damping properties, and that the outer damping element 9 is made of a material which achieves a 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 comprise a bottom 24 and be provided with an extension 25 for fastening, similar to that shown in fig. 5. 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 appropriate, 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 designed as a pin or as a casting. 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, preferably smaller than 20% and particularly preferably smaller than 10% of the diameter of the bearing element 8.

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

According to an advantageous first embodiment, the projections 32 can be applied directly during the production of the damping element 9 or can be injection-molded directly together as a plastic injection-molded part during the production of the damping element 9. The safety bearing 12 with the damping element 9 can thus be produced very cost-effectively. It is also conceivable to configure the projection 32 in the following way: a bearing plate made of a bearing material is fastened to the bottom 24. Advantageously, such a bearing plate is injection molded together when the damping element 9 is manufactured.

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

The invention is not limited to the embodiments shown and described. Thus, in all the embodiments of the

safety bearings

10, 12 shown with the damping element 9, the bearing element 8 and the damping element 9 can also be connected to one another by means of other fastening means, for example by means of an adhesive bonding process, an extrusion process, by means of clamping means, threaded connections or the like. It should be noted here that the bearing element 8, the damping element 9 and the holder 17 can only be used once in the connection system in order to achieve the defined mounting and dismounting, respectively, in the bayonet connection and in the press connection. 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.

Further variants are also possible within the framework of the claims, as are combinations of features, even if they are shown and described in different embodiments.

Claims

1. A safety bearing (10, 12) for a rotor shaft (3) of a textile rotor (2) supported in a magnetic bearing (6) having a bearing element (8) made of a wear-resistant material configured for cooperation with a bearing surface (5, 15) of the textile rotor (2), characterized in that the safety bearing (10, 12) comprises a damping element (9) in which the bearing element (8) is accommodated.

2. The safety bearing (10, 12) as claimed in the preceding claim, characterized in that the bearing element (8) is configured as a bearing ring (8 a).

3. Safety bearing (10, 12) according to one of the preceding claims, characterized in that the damping element (9) is configured as a damping ring (9 a).

4. Safety bearing (10, 12) according to one of the preceding claims, characterized in that the damping element (9) is made of a plastic material, in particular of Polyoxymethylene (POM).

5. Safety bearing (10, 12) according to the preceding claim, characterized in that the plastic material has a modulus of elasticity of less than 3000 MPa, preferably less than 2000 MPa and particularly preferably less than 1000 MPa.

6. Safety bearing (10, 12) according to one of the preceding claims, characterized in that the damping element (9) is injection-molded directly on the bearing element (8).

7. Safety bearing (10, 12) according to one of the preceding claims, characterized in that the bearing element (8) is made of a bronze material or a brass material, in particular of a copper tin zinc alloy.

8. Safety bearing (10, 12) for a rotor shaft (3) of a textile rotor (2), in particular according to any of the preceding claims, supported in a magnetic bearing (6), having a bearing element (8) made of a wear-resistant material configured for cooperation with a bearing surface (5, 15) of the textile rotor (2), characterized in that the bearing element (8) is made of a ceramic material or of a composite material comprising a ceramic material, wherein the ceramic material preferably comprises Al₂O₃Or ZrO₂Or TiO₂Or Si₃N₄。

9. Safety bearing (10, 12) according to any of the preceding claims, characterized in that the bearing element (8) contains particles of a lubricating material, in particular nickel or graphite.

10. Safety bearing (10, 12) according to one of the preceding claims, characterized in that the safety bearing (10, 12) has a fastening means (13), in particular a part of a bayonet closure, a thread or a clamping means, to be detachably fastened on a bearing housing (16) of the magnetic bearing (6), in particular on a holder (17) of the bearing housing (16).

11. Safety bearing (10, 12) according to the preceding claim, characterized in that the fastening means (13) are provided on the damping element (9).

12. Safety bearing (10, 12) according to the preceding claim, characterized in that the damping element (9), in particular the damping ring (9 a), has a fastening hole (19) for detachable fastening on the bearing housing (16), wherein the fastening hole (19) is preferably arranged in an annular contact surface (21) of the damping element (9).

13. Safety bearing (10, 12) according to one of the preceding claims, characterized in that the safety bearing (12), in particular the damping element (9), has a closed bottom (24) which constitutes an axial safety bearing (12), wherein preferably the bottom (24) has a central elevation.

14. 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 safety bearings (10, 12) is constructed according to one of the preceding claims.

15. Bearing device according to the preceding claim, characterized in that the front safety bearing (10) is fastened, in particular screwed, directly on the bearing housing (16), in particular on a front wall (22) of the bearing housing (16).

16. Bearing device according to one of the two preceding claims, characterized in that the rear safety bearing (12) is fastened, in particular screwed, on a rear wall (23) of the bearing housing (16), in particular on a bearing cap (27) arranged on the rear wall (23).