DE102010022000A1 - Catcher bearing for magnetic bearing system, has braking device that is provided to decelerate relative rotation of inner ring portion and outer ring portion - Google Patents

Abstract

The catcher bearing (1) has an outer ring portion (5) and an inner ring portion (6) that are coupled to each other. Several rollers (7) are arranged between the inner ring portion and the outer ring section. A braking device (10) is provided to decelerate the relative rotation of the inner ring portion and outer ring portion. An independent claim is included for magnetic bearing system.

Description

Field of the invention

The invention relates to a fishing camp for securing a magnetic bearing system with an outer ring portion, with an inner ring portion and with a plurality of rolling elements over which the inner ring portion and the outer ring portion can roll to each other. The invention also relates to a magnetic bearing system with this fishing camp.

Magnetic bearing systems are usually contactless bearings that support magnetic forces, waves or axes. Such magnetic bearing systems are extremely low friction and therefore particularly interesting for applications that should have low energy consumption. However, the magnetic bearing systems are critical when they are no longer operated under optimum operating conditions and thus contact between the bearing partners of the magnetic bearing system can occur. Such impermissible operating conditions can z. B. by a fault or failure of the magnetic field or by overloading the magnetic bearing system.

For this reason, it is quite common to provide an additional, kinematically arranged parallel storage for securing a magnetic bearing system, which takes over the bearing function in impermissible operating conditions. These additional bearings are realized, for example, as a safety bearing.

Such safety bearings are for example from the document DE 10 2008 014 64 A1 known, which relates to a turbocharger with a bearing assembly for supporting a shaft of the turbocharger. Also in the publication the DE 10 2008 038 978 A1 which relates to a method and bearing for the storage of rotatable devices, in particular a medical scanner, it is proposed to provide a backup bearing for protection in addition to a magnetic bearing.

The publication DE 10 2006 019 873 B3 relates to a fishing camp for an electric machine and an electric machine with at least one such fishing camp. The fishing camp has an inner ring and an outer ring, which are mounted on sliding elements which are arranged between the inner ring and the outer ring. In case of failure of the operating conditions and thus a short or long failure of the magnetic bearing system, the inner ring slides over the sliding elements in the outer ring.

Probably the next coming state of the art is the publication DE 3 141 841 C2 formed, which proposes a centering and safety gear for contactless mounted rotors. This device has a roller bearing, which takes over the emergency running properties in case of failure of the magnetic bearing system.

description

The invention is based on the object to propose a fishing camp for a magnetic bearing system, which is functionally reliable, especially when used several times, designed.

This object is triggered by a fishing camp with the features of claim 1 and by a magnetic bearing system with the features of claim 10. Preferred or advantageous embodiments of the invention will become apparent from the dependent claims, the following description and the accompanying drawings.

In the context of the invention, a fishing camp for securing a magnetic bearing system is presented. The magnetic bearing system is preferably designed as a bearing between a shaft or an axle and a surrounding construction as a bearing partner and has at least one magnetic bearing device. The safety bearing is designed in particular for providing emergency running properties for the bearing in the event of complete or partial failure of the at least one magnetic bearing of the magnetic bearing system. Particularly preferably, the fishing camp is designed and / or arranged so that in a normal operating condition, the storage by the magnetic bearing system and in an exceptional operating condition or inadmissible operating condition, in particular a short-term or permanent deactivation of at least one magnetic bearing z. B. due to power failure, overload, etc., the backup bearing takes over the bearing function. Preferably, the backup bearing is arranged without contact in the installation situation to one of the bearing partners, wherein the bearing partner falls in an exceptional operating condition in the fishing camp (or vice versa) and this contacted.

The backup bearing is preferably formed comparable to a standard rolling bearing and has an outer ring portion and an inner ring portion, which are arranged concentrically and / or coaxially to each other. Inner ring portion and outer ring portion may be formed as an inner ring or outer ring or sections of another unit. Between the outer ring portion and the inner ring portion a plurality of rolling elements, in particular balls or rollers, optionally one or more rows arranged in any arrangement (eg. X-arrangement, O-arrangement), so that the inner ring portion and the Outer ring portion can roll in a relative rotation to each other. In the event of a failure of the magnetic bearing system, in particular radial forces are transmitted via the safety bearing from the shaft or axle to the surrounding structure.

According to the invention, the safety bearing on a braking device which couples the outer ring portion and the inner ring portion to each other, in particular brings into operative connection, and which is designed to decelerate the relative rotation of the inner ring portion and the outer ring portion.

While rolling bearings are usually designed to minimize the frictional resistance in a relative rotation of the inner ring and outer ring, the rotational resistance, in particular a frictional resistance, between the inner ring portion and outer ring portion is specifically increased in the present invention.

This particular design embodiment is based on the following consideration: In operation, the backup bearing is used when the magnetic bearing system fails. In many embodiments, the fishing camp is connected to only one of the bearing partner of the magnetic bearing system, whereas in the normal operating state between the fishing camp and the other bearing partner a distance, in particular a gap, preferably an annular gap, is predetermined. In case of failure of the at least one magnetic bearing and thus of the magnetic bearing system, the distance is bridged, so that the fishing camp contacted also the other bearing partner than the then trapped bearing partner. Due to the mostly sudden contact of the contacting ring portion is changed with a very high acceleration in the rotational speed, since the backup bearing must be set in contact with the relative speed of the two bearing partners.

It can not be ruled out that due to this high acceleration, rolling element slippage of the rolling elements can occur relative to the outer ring section and / or the inner ring section, which damages the rolling elements or the ring sections. By the inventively proposed braking device, the acceleration is reduced, it being ensured by reducing the acceleration that the resulting Wälzkörperschlupf also reduced and the backup bearing is protected so that it can be used wear-free, almost wear-free or at least low-wear.

In a preferred embodiment of the invention, the braking device with the inner ring portion or the outer ring portion is preferably connected directly rotatable, ie without interposition of the axis, shaft or surrounding construction. Particularly preferably, the safety bearing with integrated braking device forms an installable and / or self-retaining structural unit. Preferably, the braking device is designed so that it carries the other ring portion - as long as the magnetic bearing system is in normal operating state - preferably frictionally entraps or holds. The two ring sections are thus not arranged freely rotatable by the braking device.

In a preferred embodiment of the invention, the inner ring portion or the outer ring portion is rotatably coupled to a sliding bearing portion which is arranged and / or designed for supporting or supporting the backup bearing against the trapped bearing partner. The sliding bearing portion may be formed, for example, as a material layer of a softer material than the inner ring or outer ring portion. In particular, the backup bearing is designed as a three-ring bearing, which comprises as rings the outer ring portion, the inner ring portion and the sliding bearing portion. In case of failure of the magnetic bearing system, the rotational speed of the magnetic bearing system or its bearing partner is divided into several relative speeds, with a first relative speed between the trapped bearing partner and the sliding bearing portion and a second relative speed between the ring sections is set.

In a preferred embodiment of the invention, the braking device, in particular the braking force of the braking device is adjusted so that first the Geleitlagerabschnitt slides on the trapped bearing partner and the relative rotation between the outer ring portion and inner ring portion is accelerated slowed down during the sliding process. Preferably, the braking device is designed so that the friction torque which is introduced by the sliding bearing portion with the bearing partner is greater than the friction torque of the braking device to allow a moderate acceleration of the backup bearing. If the braking torque resulting from the coefficient of adhesion and the contact pressure of the braking device would be greater than the friction torque of the sliding sliding bearing section, no relative rotation would occur in the backup bearing between the outer ring and inner ring sections.

In a very robust embodiment of the invention, the braking device is designed as a mechanical braking device which has friction surfaces which build up a frictional resistance in a friction region, which justifies the deceleration of the relative rotation of the bearing partners.

In a preferred embodiment of the invention, the friction surfaces extend in a radial plane perpendicular to the axis of rotation of the backup bearing. In this embodiment, it is emphasized that no radial forces should be transmitted via the braking device, and this should be used exclusively to control the acceleration of the relative rotation.

In a preferred structural realization of the invention, the friction surfaces are seated on at least one brake disk, which is non-rotatably coupled to one of the ring sections and frictionally coupled to the other ring section via the friction surfaces.

In another constructive realization of the invention, the friction surfaces are arranged on a cylindrical surface, which is arranged coaxially to the axis of rotation of the backup bearing, wherein the friction surfaces are fixedly coupled to one ring portion and with the other ring portion on the friction surfaces. The friction surface may be turned radially outward or radially inward, the braking device being reminiscent in this embodiment of a drum brake. In order to transmit no radial forces via the braking device, it is preferred if the friction surfaces and / or the friction contact is arranged kinematically parallel to the rolling bodies or the Wälzkörperkontakten or are.

In a particularly preferred embodiment of the invention, the fishing camp on a biasing device, which bias the friction surfaces in the friction region, wherein the biasing means is rotatably coupled to the friction surfaces. Characterized in that the friction surfaces are preferably elastically biased, the braking force can be adjusted very accurately.

While in the present case only a mechanical system was discussed as a braking device, in other embodiments of the invention, a pneumatic or a hydraulic brake can be used as a braking device.

Another object of the invention relates to a magnetic bearing system for supporting an axle or a shaft relative to a surrounding structure, characterized in that the magnetic bearing system has a fishing camp according to one of the preceding claims or as described above.

Further features, advantages and effects of the invention will become apparent from the following description of preferred embodiments of the invention. Showing:

1 a schematic longitudinal section through a fishing camp of a magnetic bearing system as a first example of the invention;

2 in a similar representation, a second embodiment of the invention;

3 in a similar representation, a third embodiment of the invention;

4 in a similar representation, a fourth embodiment of the invention;

5 the embodiment in 4 in a cross section along the section line AA in the 4 ,

Corresponding or identical parts are each provided with the same or the same reference numerals.

The 1 one shows in a schematic longitudinal section a fishing camp 1 , which supports a shaft 2 towards a surrounding construction 3 intended as emergency storage. The wave 2 is opposite to the surrounding construction 3 mounted on a magnetic bearing system, which is not shown, but at least one magnetic, non-contact bearing device for the shaft 2 includes.

In a normal operating condition, the bearing of the shaft 2 in the surrounding construction 3 thus ensured by the magnetic bearing system. If a malfunction of the magnetic bearing system should occur, the bearing function of the backup bearing 1 , possibly several catch bearings 1 , accepted. The fishing camp 1 is in the normal operating state of the magnetic bearing system stationary and / or stationary to the surrounding construction 3 arranged and to the shaft 2 through a circumferential and continuous annular gap 4 separated. If the magnetic bearing system malfunctions, the position of the shaft changes 2 so that the shaft 2 to the radially inner regions of the backup bearing 1 starts, thus the annular gap 4 crossed and then through the fishing camp 1 is stored. The fishing camp 1 "Catching" the wave 2 as trapped "camp partner".

The fishing camp 1 has an outer ring 5 , an inner ring 6 and a plurality of rolling elements 7 , in this case bullets, on that between the outer ring 5 and the inner ring 6 are stored rolling. The trained as a radial bearing fishing camp 1 Instead of balls, other rolling elements can be used 7 , such as rollers, in particular cylindrical rollers having. Radial outside is the outer ring 5 non-rotatable with the surrounding construction 3 connected. Radially inside, the inner ring carries 6 a convoy storage section 8th , the wave 2 is facing and in a hollow cylindrical section coaxial to the axis of rotation 9 the wave 2 extends.

In case of failure of the magnetic bearing system contacted the shaft 2 thus the plain bearing section 8th , takes the inner ring 6 with and supported by the rolling elements 7 and the outer ring 5 in the radial direction on the surrounding structure 3 from.

However, it can be problematic if the inner ring 6 through the wave 2 accelerated too fast, because then the rolling elements 7 slip and the inner ring 6 or the outer ring 5 can damage. That's why the inner ring is 6 opposite the outer ring 5 not freely rotatable. Too high an acceleration of the inner ring 6 to avoid the catch camp 1 a braking device 10 on which rotatably with the inner ring 6 connected is. It is a goal, the relative rotation between the outer ring 5 and inner ring 6 with the braking device 10 to brake, to first the plain bearing section 8th to use as a plain bearing and then slowly the inner ring 6 to accelerate. slide bearing section 8th , Inner ring 6 and outer ring 5 thus form a three-ring bearing.

The braking device 10 includes two brake discs 11 , each one a friction lining 12 wear. The brake discs 11 and the friction linings 12 each extending in a radial plane perpendicular to a rotation axis 9 the wave 2 , The friction linings 12 lie on both sides of the front side of the outer ring 5 and thereby brake the relative rotation of inner ring 6 and outer ring 5 , The brake discs 11 are about screws 13 in the axial direction to the shaft 2 and in the direction of rotation about the axis of rotation 9 are distributed, with the inner ring 6 rotatably connected. Between the inner ring 6 and the brake discs 11 are disc springs 13 arranged, which the brake discs 11 elastic from the inner ring 6 push away in the axial direction. Alternatively, spring means may be provided which the brake discs elastically in the direction of the outer ring 5 to press. Through on the screws 13 attached nuts 15 may be a bias and / or a contact pressure of the friction linings 12 in a frictional contact 16 between the friction linings 12 and the outer ring 5 be set defined.

The friction torque in the contact area 16 is set smaller than the friction torque between the shaft 2 and the sliding bearing section 8th arises to an acceleration of the inner ring 6 to enable.

The 2 shows a similar representation of a second embodiment of the invention, which is structurally different. Instead of an inner ring 6 with an integrated inner ring portion, the second embodiment shows an inner ring portion 17 who is on a carrier 18 sitting, the carrier 18 is formed in the longitudinal section shown L-shaped. The on the shaft 2 adjacent legs of the wearer 18 carries on the radial inside again the plain bearing section 8th , the standing leg of the wearer 18 is, however, designed as a contact shoulder, which at the same time the friction lining 12 wearing. Between the standing leg of the wearer 18 and the inner ring portion 17 are again disc springs 13 arranged. On the other side is on the lying leg of the wearer 18 a brake disc 11 put on and with the help of another disc spring 13 biased in the axial direction. The bias voltage is controlled by a nut 19 generated, which on the lying leg of the carrier 18 on a particular self-locking thread 20 is screwed on.

While in the 1 and 2 each embodiments have been shown in which the fishing camp 1 in normal operation stationary with the surrounding construction 3 may be in other embodiments, the fishing camp 1 with the wave 2 rotate with or instead of the shaft 2 be provided an axle and the fishing camp 1 be stationary and stationary on the axis. In this case, the sliding bearing section 8th and the braking device 11 on the outer ring 5 arranged. This application is in the 3 clarifies, but which shows a further structural modification.

The 3 illustrates a third embodiment of a backup bearing 1 in which on the shaft 2 the inner ring 6 as well as brake discs 11 are rotatably mounted. However, the brake discs are 11 slidably disposed in the axial direction. An outer ring section 21 is in the carrier 18 arranged, the carrier 18 however, is located radially outward and on its radial outer side the plain bearing section 8th wearing. About a mother 19 can plate springs 13 as well as the brake discs 11 be biased in the axial direction, so that again a defined frictional torque between the inner ring 6 and outer ring section 21 can be introduced. In this embodiment, it is provided that in case of failure of the magnetic bearing system, the carrier 18 together with the outer ring portion 21 the surrounding construction 3 contacted and braked by this or taken.

The 4 shows a fourth embodiment of the invention, wherein the braking device 10 as a drum brake and thus the entire fishing camp 1 constructively designed differently. On the right side of the backup camp 1 in the 4 is an outer ring section 21 and an inner ring portion 22 to recognize, between which the rolling elements 7 can shift. On the left side is an annular chamber 23 between outer ring section 21 and inner ring section 22 provided in the one drum brake 24 as a braking device 10 is arranged. The drum brake 24 is radially inward with the inner ring portion 22 rotatably connected and presses with a friction lining 12 in the radial direction against the outer ring portion 21 to generate the friction torque. Thus, the frictional contact 16 in the embodiment in the 4 on a hollow cylindrical surface around the axis of rotation 9 and arranged in the preceding embodiments on an end face.

The 5 shows the fishing camp 1 in the 4 in a cross section through the axis of rotation 9 along the section line AA, where it can be seen that the drum brake 24 with an inner sleeve segment 25 rotatably on the inner ring section 22 sits, over a footbridge 26 with an outer sleeve segment 27 connected, which is the friction lining 12 wearing. To generate a defined friction torque is an expander device 28 provided, which is the half-divided, outer sleeve segment 27 at a division point in the direction of rotation can press apart. The expander device 28 is as a mother 29 formed, in each case on both sides a threaded rod 30 of two halves of the outer sleeve segment 27 intervene, By twisting the nut 29 become the threaded rods 30 either pushed apart or moved towards each other, so that over the two halves of the outer sleeve segment 27 the contact pressure of the friction linings 12 against the radially inner surface of the outer ring portion 21 can be adjusted. To measure the contact force with which the sleeve segment 27 to the outer ring section 21 presses, it would be conceivable, for example, to attach a strain gauge.

Advantageous in the solutions according to the 3 - 5 is that the braking effect on the outer ring section 21 takes place and thus heat can be dissipated quickly into the surrounding construction. In addition, the friction radius of the sliding bearing section increases 8th , so that the sliding bearing induces a higher friction torque and thus the braking torque of the braking device can be set larger, which in turn the rolling elements 7 prevents you from slipping more.

LIST OF REFERENCE NUMBERS

1

safety bearing

2

wave

3

adjacent construction

4

annular gap

5

outer ring

6

inner ring

7

rolling elements

8th

slide bearing section

9

axis of rotation

10

braking means

11

brake discs

12

friction linings

13

Belleville spring

14

empty

15

nuts

16

frictional

17

Inner ring section

18

carrier

19

mother

20

thread

21

Outer ring section

22

Inner ring section

23

annular chamber

24

drum brake

25

sleeve segment

26

web

27

sleeve segment

28

Expander device

29

mother

30

threaded rod

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10200801464 A1 [0004]
• DE 102008038978 A1 [0004]
• DE 102006019873 B3 [0005]
• DE 3141841 C2 [0006]

Claims (10)

Fishing camp ( 1 ) for securing a magnetic bearing system with an outer ring section ( 5 . 21 ) with an inner ring section ( 6 . 22 ) and with a plurality of rolling elements ( 7 ), over which the inner ring section ( 5 . 21 ) and the outer ring section ( 6 . 22 ) can roll to each other, characterized by a braking device ( 10 ) over which the outer ring section ( 5 . 21 ) and the inner ring section ( 6 . 22 ) are coupled together and for braking a relative rotation of inner ring section ( 6 . 22 ) and outer ring portion is formed ( 5 . 21 ). Fishing camp ( 1 ) according to claim 1, characterized in that the braking device ( 10 ) with the inner ring section ( 6 . 22 ) or the outer ring section ( 5 . 21 ) is rotatably connected and in the unfastened state of the backup bearing ( 1 ) the other ring section ( 6 . 22 ; 5 . 21 ) preferably frictionally entrains. Fishing camp ( 1 ) according to claim 1 or 2, characterized in that the inner ring section ( 6 . 22 ) and / or the outer ring section ( 5 . 21 ) rotatably with a plain bearing section ( 8th ), which is used to support the backup bearing ( 1 ) against a trapped partner ( 2 . 3 ) is arranged and / or formed. Fishing camp ( 1 ) according to one of the preceding claims, characterized in that the braking device ( 10 ) is designed as a mechanical braking device. Fishing camp ( 1 ) according to claim 4, characterized in that the braking device ( 10 ) Friction surfaces ( 12 ), which are formed and / or arranged such that in a relative rotation of inner ring portion ( 6 . 22 ) and outer ring section ( 5 . 21 ) in a friction region ( 16 ) a frictional resistance is built up. Fishing camp ( 1 ) according to claim 5, characterized in that the friction surfaces ( 12 ) in a radial plane perpendicular to the axis of rotation ( 9 ) of the fishing camp ( 1 ). Fishing camp ( 1 ) according to one of claims 5 or 6, characterized in that the friction surfaces ( 12 ) on at least one brake disc ( 11 ), which with one of the ring sections ( 6 . 22 ; 5 . 21 ) is rotatably coupled and with the other ring section ( 6 . 22 ; 5 . 21 ) over the friction surfaces ( 12 ) is frictionally coupled. Fishing camp ( 1 ) according to claim 4, characterized in that the friction surfaces ( 12 ) extend on a cylindrical surface which is coaxial with the axis of rotation ( 9 ) of the fishing camp ( 1 ) is arranged. Fishing camp ( 1 ) according to one of claims 5 to 8, characterized by a pretensioning device ( 13 ), the friction surfaces ( 12 ) in the friction region ( 16 ), wherein the pretensioning device ( 13 ) with the brake disc ( 11 ) is rotatably coupled. Magnetic bearing system with two bearing partners ( 2 . 3 ), which are mounted on at least one magnetic bearing means to each other, characterized by a fishing camp ( 1 ) according to any one of the preceding claims.

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