Magnetic suspension bearing capable of quickly disassembling and assembling rotating shaft and test board

Abstract

The magnetic suspension bearing comprises an outer ring stator and an inner ring rotor, the inner ring rotor comprises an outer cylinder body and an inner cylinder body which are coaxially arranged, an annular cavity is formed between the outer cylinder body and the inner cylinder body, the two ends of the annular cavity are sealed, a plurality of annular grooves are formed in the outer wall of the inner cylinder body at intervals, and the outer wall of the inner cylinder body is provided with a plurality of through holes. An oil injection channel is arranged in the cylinder wall of the outer cylinder, a first port of the oil injection channel is located on one end face of the outer cylinder, a second port of the oil injection channel is located on the inner wall of the outer cylinder and communicated with the annular cavity, and a plunger screw is in threaded connection with the first port. By adopting the magnetic suspension bearing, the rotating shaft can be quickly mounted and dismounted, the operation is simple, time and labor are saved, special auxiliary equipment is not needed during mounting, the mounting steps and conditions are simplified, special equipment is not needed during dismounting, the rotating shaft is dismounted without damage, the service life of the rotating shaft is prolonged, and the cost loss is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of magnetic bearings, in particular to a magnetic bearing capable of quickly disassembling and assembling a rotating shaft and a test bench. Background Art

[0002] Magnetic bearings use magnetic force to suspend the rotor in the air, so that there is no mechanical contact between the rotor and the stator. Magnetic bearings have the advantages of low mechanical wear, low energy consumption, low noise, long life, no lubrication, and no oil pollution. They are particularly suitable for special environments such as high speed, vacuum, and ultra-clean. With the continuous advancement and development of science and technology, the performance of magnetic bearings is also constantly improving, but there are still many difficulties in this technical field, such as the research on shaft materials and shaft dynamic characteristics. In practice, shaft materials and shaft dynamic characteristics are generally studied through a large number of experiments, and each experiment requires installation and disassembly of the shaft. In the prior art, the inner ring rotor and shaft of the magnetic bearing usually adopt an interference fit, and are generally installed by a press, a copper hammer or hot installation. Disassembly also requires special equipment. Frequent installation and disassembly are time-consuming and labor-intensive, and irreversible damage to the magnetic bearing and shaft is often caused during the disassembly process.

[0003] In addition, in the traditional way of clamping the rotating shaft, the conventional clamping force on the rotating shaft cannot be made equal everywhere, which usually leads to a certain degree of misalignment between the rotating shaft and the inner hole of the rotor, such as Figure 6 As shown, this misalignment problem may cause damage to the magnetic bearing during disassembly and assembly, and may also cause unstable bearing operation, resulting in additional vibration and imbalance during operation.

[0004] In view of this, it is necessary to improve the existing technology. Utility Model Content

[0005] The purpose of the utility model is to provide a magnetic bearing capable of quickly disassembling and assembling a rotating shaft, aiming to solve at least one of the technical problems existing in the above-mentioned prior art. To achieve the above-mentioned purpose, the technical solution adopted is as follows:

[0006] A magnetic bearing capable of quickly disassembling a rotating shaft comprises an outer ring stator and an inner ring rotor, wherein the inner ring rotor comprises an outer cylinder and an inner cylinder arranged coaxially, an annular cavity is formed between the outer cylinder and the inner cylinder, both ends of the annular cavity are sealed, a plurality of annular grooves are arranged at intervals on the outer wall of the inner cylinder, each annular groove is communicated with the annular cavity, an oil injection channel is arranged inside the cylinder wall of the outer cylinder, a first port of the oil injection channel is located at an end face of the outer cylinder, a second port is located at the inner wall of the outer cylinder and is communicated with the annular cavity, and a plunger screw is threadedly connected at the first port;

[0007] The annular cavity is filled with hydraulic oil through the oil filling channel. When the plunger screw is screwed in, pressure is generated in the hydraulic oil and the inner diameter of the inner cylinder is reduced.

[0008] Preferably, the wall thickness of the inner cylinder is smaller than the wall thickness of the outer cylinder.

[0009] Preferably, the material strength of the inner cylinder is lower than the material strength of the outer cylinder.

[0010] Preferably, the inner wall of the inner cylinder is provided with a load-balancing groove structure to make the stress deformation of the inner cylinder more uniform.

[0011] Preferably, there are four annular grooves, and two adjacent annular grooves are arranged at equal intervals.

[0012] Preferably, the inner wall of the oil injection channel is provided with a stepped boss structure, which serves to limit the screwing-in of the plunger screw.

[0013] Preferably, the oil injection channel is L-shaped, and comprises a transverse channel and a vertical channel that are connected, the transverse channel is arranged along the radial direction of the outer cylinder, and the vertical channel is arranged along a direction parallel to the axial direction of the outer cylinder.

[0014] Preferably, the length of the transverse channel is half the wall thickness of the outer cylinder.

[0015] Preferably, the length of the vertical channel is half the length of the outer cylinder.

[0016] The utility model also provides a magnetic bearing test bench, including a base, on which bearing mounting seats are symmetrically installed on the left and right sides, each bearing mounting seat is installed with a magnetic bearing as described above that can quickly disassemble and assemble the rotating shaft, and the two magnetic bearings are coaxially arranged.

[0017] Compared with the prior art, the utility model has the following beneficial effects:

[0018] The utility model discloses a magnetic bearing capable of quickly disassembling and assembling a rotating shaft. The installation and disassembly of the rotating shaft are quick and easy to operate, saving time and effort. No special auxiliary equipment is required during installation, thus simplifying the installation steps and conditions. No special equipment is required during disassembly, and the disassembly does not damage the rotating shaft, thus extending the service life of the rotating shaft and reducing cost losses.

[0019] The shaft is clamped hydraulically. The clamping force on the shaft is equal everywhere through the thin wall of the inner cylinder, that is, the inner diameter deformation of the inner cylinder is equal, so that the shaft and the magnetic floating rotor remain perfectly concentric, thus having a unique ultra-high clamping accuracy, eliminating the unbalanced force caused by misalignment, and is particularly suitable for high-speed applications.

[0020] In addition, during the experiment, the vibration of the rotating shaft is first transmitted to the hydraulic oil through the thin wall of the inner cylinder, and then transmitted outward through the hydraulic oil. Since the vibration needs to be transmitted through the hydraulic oil, and the hydraulic oil has excellent damping properties, the structure has excellent vibration reduction performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solution of the present invention, the following is a brief introduction to the drawings required for use in the implementation. Obviously, the drawings described below are only some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a schematic diagram of the overall structure of the magnetic bearing of Example 1.

[0023] Figure 2 It is a cross-sectional view of the magnetic bearing of the first embodiment.

[0024] Figure 3 It is a cross-sectional view of the inner ring rotor of the first embodiment.

[0025] Figure 4 It is a schematic diagram of the coordination between the boss structure and the clamping platform structure in the first embodiment.

[0026] Figure 5 It is a schematic diagram of the force on the hydraulic clamping shaft of the magnetic bearing in the first embodiment.

[0027] Figure 6 This is a schematic diagram of the forces on a conventional bearing clamped rotating shaft.

[0028] Figure 7 It is a schematic diagram of the overall structure of the test bench of Example 2.

[0029] In the figure: 1. outer ring stator; 2. inner ring rotor; 3. outer cylinder; 4. inner cylinder; 5. annular cavity; 6. annular groove; 7. transverse channel; 8. vertical channel; 9. stepped boss structure; 10. plunger screw; 11. stepped clamping structure; 12. load-equalizing groove structure; 13. rotating shaft; 14. base; 15. bearing mounting seat. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] Embodiment 1

[0033] like Figures 1 to 3 As shown, a preferred embodiment of the utility model provides a magnetic bearing capable of quickly disassembling and assembling a rotating shaft, and the magnetic bearing comprises an outer ring stator 1 and an inner ring rotor 2.

[0034] The inner ring rotor 2 includes an outer cylinder 3 and an inner cylinder 4. Both the outer cylinder 3 and the inner cylinder 4 are cylindrical structures with hollow interiors. The wall thickness of the inner cylinder 4 is smaller than that of the outer cylinder 3, and the material strength of the inner cylinder 4 is lower than that of the outer cylinder 3. Specifically, the outer cylinder 3 is made of alloy steel or titanium alloy. In this embodiment, alloy steel 42CrMo is preferably used. The material of the inner cylinder 4 is spring steel. Commonly used materials include 60Si2Mn, 65Mn, and 50Cr4V. In this embodiment, 65Mn is preferably used.

[0035] The inner cylinder 4 is assembled in the outer cylinder 3, and the inner cylinder 4 and the outer cylinder 3 are arranged coaxially, and an annular cavity 5 is formed between the inner cylinder 4 and the outer cylinder 3. The two ends of the annular cavity 5 are sealed, and the annular cavity 5 is used to inject hydraulic oil. The hydraulic oil can be L-HL hydraulic oil, L-HM anti-wear hydraulic oil, L-HV low-temperature anti-wear hydraulic oil, L-HS low-suspect anti-wear liquid oil or L-HG hydraulic guide rail oil. Among them, the viscosity grades of hydraulic oil are divided into 22#, 32#, 46#, 68#, and 100# based on the viscosity at 40°C. Considering the boundary constraints such as the annular cavity structure design and the operating environment of this embodiment, it is better to select a product model in the middle for the viscosity requirement of hydraulic oil. This embodiment preferably uses L-HM32#.

[0036] A plurality of annular grooves 6 are provided at intervals on the outer wall of the inner cylinder 4 , and each annular groove 6 is connected to the annular cavity 5 . Preferably, in the present invention, four annular grooves 6 are provided, and two adjacent annular grooves 6 are arranged at equal intervals.

[0037] An oil injection channel is provided inside the cylinder wall of the outer cylinder 3, and the oil injection channel includes a transverse channel 7 and a vertical channel 8. The transverse channel 7 is arranged along the radial direction of the outer cylinder 3, and the length of the transverse channel 7 is half of the wall thickness of the outer cylinder 3. The vertical channel 8 is arranged along the direction parallel to the axial direction of the outer cylinder 3, and the length of the vertical channel 8 is half of the length of the outer cylinder 3. The transverse channel 7 and the vertical channel 8 are connected to form an L-shaped oil injection channel. The first port of the L-shaped oil injection channel, that is, the port of the vertical channel 8, is located at one end face of the outer cylinder 3, and the second port of the L-shaped oil injection channel, that is, the port of the transverse channel 7, is located on the inner wall of the outer cylinder 3 and is connected to the annular cavity 5. The hydraulic oil is injected into the annular cavity 5 through the L-shaped oil injection channel.

[0038] like Figure 4 As shown, the vertical channel 8 is divided into a first section and a second section, the first section is close to the first port, and the inner diameter of the first section is larger than that of the second section, thereby forming a stepped boss structure 9 at the connection between the first section and the second section. An internal thread is provided on the inner wall of the first section, and the section is threadedly connected with a plunger screw 10, and a stepped clamping platform structure 11 is provided on the outer wall of the plunger screw 10. When the plunger screw 10 is screwed inward, the stepped clamping platform structure 11 is clamped on the stepped boss structure 9, which plays a role in limiting the screwing of the plunger screw 10.

[0039] The installation and removal process of the rotating shaft in this embodiment is described as follows:

[0040] When installing the rotating shaft, first insert the rotating shaft into the hole of the inner cylinder 4, and then screw in the plunger screw 10. During the screwing process, the oil storage space in the oil injection channel will become smaller, and the hydraulic oil will be pressed into the annular cavity 5 from the oil injection channel. The hydraulic oil in the annular cavity 5 will generate a certain pressure, and the wall thickness of the inner cylinder 4 is relatively thin, and the inner diameter is reduced under pressure, thereby achieving expansion and clamping of the rotating shaft. On the contrary, when removing the rotating shaft, the plunger screw 10 is screwed in the opposite direction, the oil storage space in the oil injection channel will become larger, and the hydraulic oil will flow back from the annular cavity 5 to the oil injection channel. The hydraulic oil pressure in the annular cavity 5 is reduced, and the inner diameter of the inner cylinder 4 is restored to its original state, thereby achieving loosening the clamping of the rotating shaft.

[0041] Through the cooperation of the above-mentioned stepped clamping platform structure 11 and the stepped boss structure 9, a stop effect is played on the screwing-in of the plunger screw 10, and a high-precision clamping force can be achieved. There is no need to repeatedly screw in or out to adjust the pressure, which saves installation time.

[0042] In addition, in the above structure, the inner and outer cylinders are made of materials with different strengths and are designed to be thick on the outside and thin on the inside. The purpose is to make the inner cylinder 4 easy to deform and generate clamping force. The outer cylinder 3 has high strength and is suitable for overcoming the centrifugal expansion force under ultra-high speed rotation.

[0043] Furthermore, a load-balancing groove structure 12 is provided on the inner wall of the inner cylinder 4. The load-balancing groove structure 12 can be selected as a single groove or multiple grooves according to the axial size, and can be set to an annular groove, an arc groove or a special-shaped groove in shape. The purpose of setting the load-balancing groove structure 12 is to make the stress deformation of the inner cylinder 4 more uniform.

[0044] To sum up, the magnetic bearing capable of quickly disassembling and assembling the rotating shaft described in the embodiment of the utility model has the advantages of quick installation and disassembly of the rotating shaft, simple operation, saving time and effort, no need for special auxiliary equipment during installation, simplifying the installation steps and conditions, no need for special equipment during disassembly, and no damage to the rotating shaft, thereby extending the service life of the rotating shaft and reducing cost losses.

[0045] like Figure 5 As shown, in this embodiment, hydraulic clamping of the rotating shaft 13 is adopted. The clamping force acting on the rotating shaft 13 through the thin wall of the inner cylinder is equal everywhere, that is, the inner diameter deformation of the inner cylinder is equal, so that the rotating shaft and the magnetic floating rotor are kept perfectly concentric, and thus have a unique ultra-high clamping accuracy, eliminating the unbalanced force caused by misalignment, and are particularly suitable for high-speed applications.

[0046] In addition, during the experiment, the vibration of the rotating shaft is first transmitted to the hydraulic oil through the thin wall of the inner cylinder, and then transmitted outward through the hydraulic oil. Since the vibration needs to be transmitted through the hydraulic oil, and the hydraulic oil has excellent damping properties, the structure has excellent vibration reduction performance.

[0047] Embodiment 2

[0048] like Figure 7 As shown, a preferred embodiment of the utility model provides a magnetic bearing test bench, which includes a base 14, on which bearing mounting seats 15 are symmetrically installed on the left and right sides, and each bearing mounting seat 15 is installed with a magnetic bearing capable of quickly disassembling and assembling a rotating shaft as described in the above-mentioned embodiment 1, and the two magnetic bearings are coaxially arranged.

[0049] The rotating shaft 13 is used as the object to be tested and is installed on the test bench. Specifically, both ends of the rotating shaft 13 are detachably installed in the holes of the corresponding magnetic bearing inner cylinder 4. The specific installation and disassembly methods refer to the above-mentioned embodiment 1.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.

Claims

1. A magnetic bearing capable of quickly disassembling a rotating shaft, comprising an outer ring stator and an inner ring rotor, characterized in that: The inner ring rotor comprises an outer cylinder and an inner cylinder arranged coaxially, an annular cavity is formed between the outer cylinder and the inner cylinder, both ends of the annular cavity are sealed, a plurality of annular grooves are arranged at intervals on the outer wall of the inner cylinder, each annular groove is communicated with the annular cavity, an oil injection channel is arranged inside the cylinder wall of the outer cylinder, a first port of the oil injection channel is located at one end face of the outer cylinder, a second port is located at the inner wall of the outer cylinder and is communicated with the annular cavity, and a plunger screw is threadedly connected at the first port; The annular cavity is filled with hydraulic oil through the oil filling channel. When the plunger screw is screwed in, pressure is generated in the hydraulic oil and the inner diameter of the inner cylinder is reduced.

2. A magnetic bearing capable of quickly disassembling and assembling a rotating shaft according to claim 1, characterized in that: The wall thickness of the inner cylinder is smaller than the wall thickness of the outer cylinder.

3. The magnetic bearing capable of quickly disassembling and assembling a rotating shaft according to claim 1, characterized in that: The material strength of the inner cylinder is lower than the material strength of the outer cylinder.

4. The magnetic bearing capable of quickly disassembling and assembling a rotating shaft according to claim 1, characterized in that: The inner wall of the inner cylinder is provided with a load-equalizing groove structure, so that the stress deformation of the inner cylinder is more uniform.

5. The magnetic bearing capable of quickly disassembling and assembling a rotating shaft according to claim 1, characterized in that: There are four annular grooves, and two adjacent annular grooves are arranged at equal intervals.

6. The magnetic bearing capable of quickly disassembling and assembling a rotating shaft according to claim 1, characterized in that: The inner wall of the oil injection channel is provided with a stepped boss structure, which serves to limit the screwing-in of the plunger screw.

7. The magnetic bearing capable of quickly disassembling and assembling a rotating shaft according to claim 1, characterized in that: The oil injection channel is L-shaped, and comprises a transverse channel and a vertical channel that are connected. The transverse channel is arranged along the radial direction of the outer cylinder, and the vertical channel is arranged along a direction parallel to the axial direction of the outer cylinder.

8. The magnetic bearing capable of quickly disassembling and assembling a rotating shaft according to claim 7, characterized in that: The length of the transverse channel is half of the wall thickness of the outer cylinder.

9. The magnetic bearing capable of quickly disassembling and assembling a rotating shaft according to claim 7, characterized in that: The length of the vertical channel is half the length of the outer cylinder.

10. A magnetic bearing test bench, comprising a base, on which bearing mounting seats are symmetrically mounted on the left and right sides, characterized in that: A magnetic bearing capable of quickly disassembling and assembling a rotating shaft as described in any one of claims 1 to 9 is installed in each bearing mounting seat, and the two magnetic bearings are coaxially arranged.

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