Magnetic suspension bearing rotating speed synchronous protection device based on planar magnetic transmission coupler

Abstract

The invention relates to the technical field of magnetic suspension bearings, and discloses a magnetic suspension bearing rotating speed synchronous protection device based on a plane magnetic transmission coupler. The device comprises a transmission shaft, a rotating speed synchronization unit, a protection bearing, a magnetic suspension rotor and a protection shaft sleeve, the rotating speed synchronization unit comprises a transmission shaft end coupler, a protection bearing connector, first magnets and second magnets, one end of the transmission shaft end coupler is connected with the transmission shaft, and the other end of the transmission shaft end coupler is provided with a plurality of second magnets; n poles and S poles of the multiple second magnets are alternately arranged, one end of the protection bearing connector is connected with the protection bearing inner ring, the other end of the protection bearing connector is provided with the multiple first magnets, N poles and S poles of the multiple first magnets are alternately arranged, the rotating speed synchronization unit and the protection bearing inner ring are located on the same axis, and the protection shaft sleeve is detachably arranged at the shaft neck of the magnetic suspension rotor. The protective bearing connector corresponds to and is spaced from the protective bushing by a predetermined gap. Therefore, the magnetic suspension bearing shaft system can be protected.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic levitation bearings, and particularly to a magnetic levitation bearing rotational speed synchronization protection device based on a planar magnetic force transmission coupling. Background Art

[0002] As a precision mechanical structure, magnetic levitation bearings have the advantages of no lubrication, no wear, low noise, low loss, high rotational speed, etc. Therefore, magnetic levitation bearings are particularly suitable for applications that require high-speed rotation. In a magnetic levitation bearing system, to ensure the safety and stability of the magnetic levitation bearing system, a set of protection bearings (also known as backup bearings, emergency bearings) are often installed in the magnetic levitation bearing system. The main purpose is to support the high-speed rotating rotor system by the protection bearings for a short time in the event of the failure or overload of the magnetic levitation bearings, so as to prevent damage to the equipment and thus ensure the safety and reliability of the entire system.

[0003] In the normal working state of the magnetic levitation bearing system, the magnetic levitation rotor does not come into contact with the stator. However, after the failure or overload of the magnetic levitation bearing, the following three situations are likely to occur: 1) The full-circumference friction formed by the collision and friction between the high-speed rotating rotor and the inner ring of the bearing after falling will intensify the intensity of the collision motion; 2) The falling of the rotor will bring huge vibrations and impacts to the rolling bearing; 3) The rotor falls on the rolling bearing and drives the bearing to rotate. When the bearing is accelerated and subjected to impact loads, it is prone to slipping, resulting in scratches and wear on the raceway surface.

[0004] All of the above three situations will cause damage to the shaft system - protection bearing. Among them, the full-circumference friction in situation 1) causes the greatest damage to the shaft system - protection bearing. Therefore, a bearing protection device is needed that can effectively reduce or even avoid the generation of full-circumference friction, and thus reduce or even avoid the damage of the magnetic levitation bearing shaft system. Summary of the Invention

[0005] The present invention provides a magnetic levitation bearing rotational speed synchronization protection device based on a planar magnetic force transmission coupling, which can solve the problems in the prior art.

[0006] The present invention provides a magnetic suspension bearing speed synchronization protection device based on a planar magnetic drive coupling. The device includes a drive shaft, a speed synchronization unit, a protection bearing, a magnetic suspension rotor, and a protection sleeve. The speed synchronization unit includes a drive shaft end coupling, a protection bearing connector, a first magnet, and a second magnet. One end of the drive shaft end coupling is connected to the drive shaft, and a plurality of the second magnets are arranged at the other end. The N poles and S poles of the plurality of second magnets are arranged alternately. One end of the protection bearing connector is connected to the inner ring of the protection bearing, and a plurality of the first magnets are arranged at the other end. The N poles and S poles of the plurality of first magnets are arranged alternately. The speed synchronization unit and the inner ring of the protection bearing are located on the same axis. The protection sleeve is detachably arranged at the journal of the magnetic suspension rotor. The protection bearing connector corresponds to the protection sleeve and is spaced apart by a predetermined gap.

[0007] Preferably, the drive shaft end coupling and the drive shaft are circumferentially fixed by a flat key and axially positioned and clamped by a fixing member.

[0008] Preferably, a plurality of second slots are arranged at the other end of the drive shaft end coupling, and the plurality of second slots are used to arrange the plurality of second magnets.

[0009] Preferably, a plurality of first slots are arranged at the other end of the protection bearing connector, and the plurality of first slots are used to arrange the plurality of first magnets.

[0010] Preferably, the first magnet and the second magnet are in a fan shape.

[0011] Preferably, there is an angular interval of 30° between every two adjacent first magnets, and there is an angular interval of 30° between every two adjacent second magnets.

[0012] Preferably, the first magnet and the second magnet are rubidium magnets.

[0013] Preferably, the protection bearing is an angular contact ball bearing.

[0014] Preferably, the materials of the drive shaft end coupling and the protection bearing connector are aluminum alloy or titanium alloy.

[0015] Preferably, the magnetic suspension rotor is interference-connected with the protection sleeve at the journal, and the protection bearing connector is interference-connected with the protection bearing.

[0016] Through the above technical solutions, a certain speed can be given to the inner ring of the protection bearing, so as to reduce or even avoid the magnetic suspension bearing shaft system from falling into the full-circumference friction state, realizing the protection of the magnetic suspension bearing shaft system; moreover, the speed synchronization device has a simple structure and has low requirements for the coaxiality of the two shafts during installation. Description of the Drawings

[0017] The accompanying drawings included are used to provide a further understanding of the embodiments of the present invention, which form a part of the specification, for illustrating the embodiments of the present invention, and for explaining the principles of the present invention together with the written description. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 Shows a schematic diagram of a magnetic suspension bearing speed synchronization protection device based on a planar magnetic force transmission coupling according to an embodiment of the present invention;

[0019] Figures 2A - 2C Shows a part drawing of a drive shaft end coupling in the speed synchronization protection device according to an embodiment of the present invention;

[0020] Figures 3A - 3C Shows a part drawing of a protection bearing connector in the speed synchronization protection device according to an embodiment of the present invention;

[0021] Figure 4 Shows a schematic diagram of a speed synchronization unit according to an embodiment of the present invention;

[0022] Figures 5A - 5B Is a simulation diagram of the falling motion of a magnetic suspension bearing shaft system without using the speed synchronization protection device of the present invention;

[0023] Figures 6A - 6B Is a simulation diagram of the falling motion of a magnetic suspension bearing shaft system using the speed synchronization protection device of the present invention.

[0024] Explanation of reference numerals

[0025] 1 Magnetic suspension rotor; 2 Protection sleeve; 3 Protection bearing; 4 Protection bearing connector;

[0026] 5 First magnet; 6 Second magnet; 7 Drive shaft end coupling; 8 Flat key;

[0027] 9 Fixing part; 10 Drive shaft. Detailed implementation manners

[0028] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0029] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0030] Unless otherwise specifically stated, the relative arrangements of the components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for the sake of convenience of description, the sizes of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and devices should be regarded as part of the authorization specification. In all the examples shown and discussed herein, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0031] Figure 1 The schematic diagram of a magnetic suspension bearing rotational speed synchronization protection device based on a planar magnetic force transmission coupling according to an embodiment of the present invention is shown.

[0032] As Figure 1As shown in the figure, an embodiment of the present invention provides a magnetic suspension bearing speed synchronization protection device based on a planar magnetic force transmission coupling. The device includes a drive shaft 10, a speed synchronization unit, a protection bearing 3, a magnetic suspension rotor 1, and a protection bushing 2. The speed synchronization unit includes a drive shaft end coupling 7, a protection bearing connector 4, a first magnet 5, and a second magnet 6. One end of the drive shaft end coupling 7 is connected to the drive shaft 10, and the other end is provided with a plurality of the second magnets 6. The plurality of the second magnets 6 are arranged in an alternating manner of N poles and S poles. One end of the protection bearing connector 4 is connected to the inner ring of the protection bearing 3, and the other end is provided with a plurality of the first magnets 5. The plurality of the first magnets 5 are arranged in an alternating manner of N poles and S poles. The speed synchronization unit and the inner ring of the protection bearing 3 are located on the same axis. The protection bushing 2 is detachably arranged at the journal of the magnetic suspension rotor 1. The protection bearing connector 4 corresponds to the protection bushing 2 and is spaced apart by a predetermined gap.

[0033] Through the above technical solution, a certain speed can be given to the inner ring of the protection bearing, thereby reducing or even avoiding the magnetic suspension bearing shaft system from falling into the full-circumference friction state, and realizing the protection of the magnetic suspension bearing shaft system. Moreover, the speed synchronization device has a simple structure and does not have high requirements for the coaxiality of the two shafts during installation.

[0034] Among them, the drive shaft can be connected to the motor through a coupling. The motor can give a certain speed to the inner ring of the protection bearing, and the speed of the inner ring can be controlled by the motor. The protection bushing can reduce the wear degree of the magnetic suspension rotor during collision.

[0035] According to an embodiment of the present invention, the drive shaft end coupling 7 and the drive shaft 10 are circumferentially fixed by a flat key 8 and axially positioned and clamped by a fixing member 9.

[0036] Specifically, a keyway is provided at one end of the drive shaft 10 connected to the drive shaft end coupling 7. The keyway is used to set the flat key, and the circumferential fixation of the drive shaft 10 and the drive shaft end coupling 7 is realized through the cooperation of the keyway and the flat key. For example, the fixing member 9 can be a set screw, and the number can be 2.

[0037] According to an embodiment of the present invention, a plurality of second slots are provided at the other end of the drive shaft end coupling 7. The plurality of second slots are used to set the plurality of second magnets 6.

[0038] For example, the number of the second slots is six, and the number of the second magnets 6 is six.

[0039] According to an embodiment of the present invention, a plurality of first slots are provided at the other end of the protection bearing connector 4. The plurality of first slots are used to set the plurality of first magnets 5.

[0040] For example, the number of the first slots is six, and the number of the first magnets 6 is six.

[0041] According to an embodiment of the present invention, the shapes of the first magnet 5 and the second magnet 6 are sector-shaped.

[0042] According to an embodiment of the present invention, there is a spacing angle of 30° between every two adjacent first magnets 5, and there is a spacing angle of 30° between every two adjacent second magnets 6.

[0043] According to an embodiment of the present invention, the first magnet 5 and the second magnet 6 can be rubidium magnets, but the present invention is not limited thereto.

[0044] According to an embodiment of the present invention, the protective bearing 3 is an angular contact ball bearing.

[0045] For example, the angular contact ball bearing can be installed in a reverse-mounted manner (i.e., in a back-to-back manner). Thus, the axial collision force that may be caused when the magnetic levitation rotor 1 drops can be borne.

[0046] According to an embodiment of the present invention, the materials of the drive shaft end coupling 7 and the protective bearing connector 4 are aluminum alloy or titanium alloy.

[0047] Those skilled in the art should understand that the above description of the materials is only exemplary and is not used to limit the present invention. For example, other metal materials with better performance can also be used to increase the torsional strength.

[0048] For example, for the drive shaft end coupling 7 and the protective bearing connector 4, the outer shape can be turned out by a lathe, holes can be drilled by a drill press, and keyways can be milled by a milling machine.

[0049] The structural diagram of the drive shaft end coupling 7 of the rotational speed synchronization unit is shown in Figure 2. Among them, at the left end of the drive shaft end coupling 7 (i.e., the end connected to the drive shaft), a keyway is axially opened for circumferential fixation with the drive shaft, and two threaded holes are opened at a circumferential interval of 90°. One of them is located above the keyway and is used for installing a set screw to play a role in axial positioning and clamping. At the right end of the drive shaft end coupling 7 of the rotational speed synchronization unit (i.e., the end where the magnets are placed), 6 sector-shaped slots are opened for placing sector-shaped magnets. Specifically, six sector-shaped magnets are arranged alternately with N poles and S poles, and the interval between each magnet is 30°.

[0050] The part drawing of the protective bearing connector 4 of the rotation speed synchronization unit is shown in Figure 3. Among them, at the left end of the protective bearing connector 4 of the rotation speed synchronization unit (i.e., the end connected to the protective bearing 3), it has an interference fit with the protective bearing. At the right end of the protective bearing connector 4 of the rotation speed synchronization unit (i.e., the end for placing magnets), there are 6 fan-shaped slots for placing fan-shaped magnets. Specifically, the N poles and S poles of the six fan-shaped magnets are arranged alternately, and the interval between each magnet is 30°.

[0051] The whole rotation speed synchronization unit and the inner ring of the protective bearing 3 are on the same axis line. When the magnetic suspension bearing shafting operates normally, start the protection device. The motor rotates and drives the drive shaft end coupling 7 to rotate. Since the N pole of the magnet of the drive shaft end coupling 7 attracts the S pole of the magnet of the protective bearing connector end 4 and at the same time repels the N poles on both sides of the magnet of the protective bearing connector end, it is ensured that within a certain torque range, the drive shaft end coupling 7 and the protective bearing connector 4 rotate synchronously. Since the protective bearing connector 4 and the inner ring of the protective bearing 3 are connected by interference fit, the inner ring of the protective bearing 3 has a certain rotation speed. Specifically, the rotation speed of the inner ring of the protective bearing 3, that is, the rotation speed of the motor, is close to and in the same rotation direction as the rotation speed of the magnetic suspension rotor 1.

[0052] In addition, the performance of the system can also be improved by increasing the number of the first magnet 5 and the second magnet 6, reducing the gap between the first magnet 5 and the second magnet 6, and replacing the magnet material.

[0053] According to an embodiment of the present invention, the magnetic suspension rotor 1 is connected with the protective sleeve 2 by interference fit at the journal, and the protective bearing connector 4 is connected with the protective bearing 3 by interference fit.

[0054] For example, the protective bearing connector 4 and the protective bearing 3 can be installed by the press-in method.

[0055] Among them, the protective sleeve 2 can play a role in restricting the axial movement of the magnetic suspension rotor 1 and protecting the magnetic suspension rotor 1 when it drops. At the same time, the protective sleeve 2 can be replaced.

[0056] Next, the working principle of the rotation speed synchronization device described in the present invention will be described with examples.

[0057] Since the N pole of the magnet of the drive shaft end coupling attracts the S pole of the magnet of the protection bearing connector end and repels the N poles on both sides of the magnet of the protection bearing connector end, the drive shaft end coupling and the protection bearing connector are ensured to rotate synchronously within a certain torque range. In actual work, the state where the true N pole and S pole are opposite only exists when there is no torque output. As long as torque is generated, there will be a certain phase angle between the protection bearing connector and the drive shaft end coupling. This angular misalignment remains and increases until the torque is large enough for the N pole of the magnet at the drive shaft end coupling to be opposite the N pole of the magnet at the protection bearing connector end, and then the drive shaft end coupling of the transmission and the protection bearing connector rotate and misalign, jumping to the next pair of coupling states. This planar transmission has a simple structure and requires low coaxiality of the two shafts during installation. Since the principle of planar attraction is adopted, the smaller the air gap, the greater the torque.

[0058] See Figure 5A and Figure 5B (where Figure 5A is the motion trajectory diagram, Figure 5B is the rotational speed change diagram), which is the simulation diagram of the drop motion of the magnetic levitation bearing shafting without using the present invention. Figure 5A The center dash line represents the boundary line of the inner ring of the protection bearing 3, and the solid line represents the motion trajectory of the magnetic levitation rotor 1 dropping. Figure 5B In Figure 5A and Figure 5B it can be seen that when the rotor drops at a self-rotation speed of 9500 r / min, the rotor undergoes a full-circumference friction phenomenon.

[0059] Refer to Figure 6A and Figure 6B (where Figure 6A is the motion trajectory diagram, Figure 6B is the rotational speed change diagram), which is the simulation diagram of the drop motion of the magnetic levitation bearing shafting based on the present invention. Figure 6A The center dash line represents the boundary line of the inner ring of the protection bearing 3, and the solid line represents the motion trajectory of the magnetic levitation rotor 1 dropping. Figure 6BThe solid line represents the rotational speed change of the inner ring of the protective bearing 3, and the dash-dotted line represents the rotational speed change of the magnetic levitation rotor 1. Here, a certain initial rotational speed is given to the inner ring of the protective bearing 3 to simulate the function that can be achieved by using the protection device described in the present invention. Since it is necessary to ensure that the rotor and the inner ring of the bearing have the same linear velocity when the rotor drops, and the radius of the inner ring of the bearing is greater than the radius of the rotor, the rotational speed of the inner ring of the bearing is set to be less than the rotational speed of the rotor. Here, the initial rotational speed of the inner ring of the protective bearing 3 is set to be approximately 9100 r / min. When the rotor drops with a self-rotational speed of 9500 r / min, only a bouncing motion occurs and it does not enter into full-circle friction. Through the comparison of the two simulation effects, it can be found that the protection device described in the present invention can largely inhibit the generation of full-circle friction.

[0060] As can be seen from the above embodiments, the magnetic levitation bearing rotational speed synchronization protection device described in the present invention has a simple structure, is convenient to install, and is easy to process. On the basis of not affecting the normal operation of the magnetic levitation bearing shafting, it can effectively reduce the phenomenon of full-circle friction occurring after the magnetic levitation bearing shafting drops, and plays a very good protective role for the magnetic levitation bearing shafting.

[0061] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom", etc. are usually based on the orientation or positional relationships shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description. Without contrary explanation, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the protection scope of the present invention; the orientation words "inner, outer" refer to the inside and outside relative to the contour of each component itself.

[0062] For the convenience of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "above" etc. can be used here to describe the spatial positional relationship between a device or feature shown in the figure and other devices or features. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation described in the figure of the device. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will be positioned as "below other devices or structures" or "under other devices or structures" afterwards. Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding explanations are made for the spatial relative descriptions used here.

[0063] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Without additional declaration, the above terms have no special meaning, and therefore should not be construed as a limitation on the protection scope of the present invention.

[0064] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A speed synchronization protection device for a magnetic levitation bearing based on a planar magnetic force transmission coupling, characterized in that, The device includes a drive shaft (10), a rotational speed synchronization unit, a protective bearing (3), a magnetic levitation rotor (1), and a protective sleeve (2). The rotational speed synchronization unit includes a drive shaft end coupling (7), a protective bearing connector (4), a first magnet (5), and a second magnet (6). One end of the drive shaft end coupling (7) is connected to the drive shaft (10), and the other end is provided with a plurality of the second magnets (6). The N poles and S poles of the plurality of the second magnets (6) are arranged alternately. One end of the protective bearing connector (4) is connected to the inner ring of the protective bearing (3), and the other end is provided with a plurality of the first magnets (5). The N poles and S poles of the plurality of the first magnets (5) are arranged alternately. The rotational speed synchronization unit and the inner ring of the protective bearing (3) are located on the same axis. The protective sleeve (2) is detachably arranged at the journal of the magnetic levitation rotor (1). The protective bearing connector (4) corresponds to the protective sleeve (2) and is spaced apart by a predetermined gap.

2. The device according to claim 1, characterized in that, The drive shaft end coupling (7) and the drive shaft (10) are circumferentially fixed by a flat key (8) and axially positioned and clamped by a fixing member (9).

3. The device according to claim 2, characterized in that, The other end of the drive shaft end coupling (7) is provided with a plurality of second slots for arranging the plurality of the second magnets (6).

4. The device according to claim 3, characterized in that, The other end of the protective bearing connector (4) is provided with a plurality of first slots for arranging the plurality of the first magnets (5).

5. The device according to claim 4, characterized in that, The first magnet (5) and the second magnet (6) are in a fan shape.

6. The device according to claim 5, characterized in that, There is an angular interval of 30° between every two adjacent first magnets (5), and there is an angular interval of 30° between every two adjacent second magnets (6).

7. The device according to any one of claims 1-6, characterized in that, The first magnet (5) and the second magnet (6) are rubidium magnets.

8. The device according to any one of claims 1-6, characterized in that, The protective bearing (3) is an angular contact ball bearing.

9. The device according to any one of claims 1-6, characterized in that, The materials of the drive shaft end coupling (7) and the protective bearing connector (4) are aluminum alloy or titanium alloy.

10. The device according to any one of claims 1-6, characterized in that, The magnetic levitation rotor (1) is interference-connected with the protective sleeve (2) at the journal, and the protective bearing connector (4) is interference-connected with the protective bearing (3).

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