Displacement sensor of magnetic suspension bearing

Abstract

The utility model belongs to the technical field of sensors, and particularly relates to a displacement sensor of a magnetic suspension bearing, which comprises two groups of supporting seats, a rotating shaft and a displacement sensor assembly fixedly mounted on one side of the supporting seats, and the two groups of supporting seats are symmetrically arranged at intervals. The two ends of the rotating shaft are suspended in the middles of the two displacement sensor assemblies respectively. The displacement sensor assembly comprises an annular magnetic conductive structure and poles, a plurality of even poles are evenly arranged on the inner ring of the magnetic conductive structure, every two adjacent poles form a sensor, at least eight sensors are formed in the inner ring of the magnetic conductive structure, the number of the sensors is multiple of 4, the sensors arranged at intervals form a main sensor group, and the main sensor group is connected with the magnetic conductive structure. The rest sensors form a redundant sensor group, and the main sensor group and the redundant sensor group are respectively connected with the power connection device. When the main sensor group breaks down, the redundant sensor can be used for continuously detecting the axial displacement change of the rotating shaft, so that the fault recognition rate of the displacement sensor in the magnetic suspension bearing is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of sensors, and in particular relates to a displacement sensor for a magnetic suspension bearing. Background Art

[0002] In the prior art, the independent core subassembly type inductive displacement sensor has obvious drawbacks. Its production process is complicated and the production cost is high. In addition, due to the inherent characteristics of the mechanical processing and assembly process, various errors will inevitably occur during the production process, making it difficult for the four independent probes to achieve a completely symmetrical state. At the same time, the geometric center of the magnetic core and the magnetic bearing shaft cannot be accurately coincident. Due to the existence of these problems, the displacement detection effect is ultimately far from the expected, and it cannot meet the high-precision detection requirements, thus limiting the application and development of this type of sensor in some fields with strict precision requirements. Utility Model Content

[0003] The purpose of the utility model is to overcome the deficiencies of the prior art, provide a displacement sensor for a magnetic bearing, improve the fault recognition rate and fault tolerance of the magnetic bearing displacement sensor, and broaden the application scope of magnetic bearings in the high-precision field.

[0004] To achieve the above purpose, the technical solution adopted by the utility model is: a displacement sensor of a magnetic suspension bearing, comprising a support seat, a rotating shaft and a displacement sensor assembly, wherein the displacement sensor assembly is fixedly mounted on one side of the support seat, two groups of support seats and displacement sensor assemblies are symmetrically and spaced apart, a channel for the rotating shaft to pass through is arranged in the middle of the displacement sensor assembly, and both ends of the rotating shaft are respectively suspended in the middle of the two displacement sensor assemblies;

[0005] The displacement sensor assembly includes a ring-shaped magnetic conductive structure and poles. A plurality of even-numbered poles are evenly arranged in the inner circle of the magnetic conductive structure. A frame is arranged on each pole. The winding is wound on the pole through the frame. Two adjacent poles form a sensor. At least eight sensors that are multiples of 4 are formed in the inner circle of the magnetic conductive structure. The sensors arranged at intervals form a main sensor group, and the remaining sensors form a redundant sensor group. The main sensor group and the redundant sensor group are respectively connected to power supply devices.

[0006] Preferably, sixteen poles are evenly arranged in the inner circle of the magnetic conductive structure, and eight sensors are formed in the inner circle of the magnetic conductive structure. Four sensors along the first radial direction and the second radial direction constitute a main sensor group. The first radial direction and the second radial direction are perpendicular to each other, and the four sensors between two adjacent main sensors constitute a redundant sensor group.

[0007] Preferably, the magnetic conductive structure and the plurality of poles are integrally formed.

[0008] Preferably, a connecting ring is protrudingly provided on one side of the support seat, and a connecting groove is correspondingly provided on one side of the magnetic conductive structure, and the connecting ring is inserted into the connecting groove.

[0009] Preferably, a receiving groove is provided on one side of the support seat close to the rotating shaft, the end of the rotating shaft is suspended in the receiving groove, and a gap is provided between the end of the rotating shaft and the support seat.

[0010] Preferably, a convex ring is protruding from one side of the support seat, the outer diameter of the convex ring is smaller than the inner diameter of the circle formed by the ends of each pole, the inner diameter of the convex ring is larger than the outer diameter of the shaft, and the shaft is suspended in the convex ring.

[0011] Preferably, the outer diameter of the rotating shaft at the position corresponding to the convex ring is larger than the outer diameter of other positions of the rotating shaft.

[0012] Preferably, the magnetic conductive structure and the pole are both made of magnetic conductive materials.

[0013] Compared with the prior art, the above technical solution has the following beneficial effects:

[0014] 1. In the utility model, two adjacent poles form a displacement sensor, and a plurality of sensors are formed in the inner circle of the magnetic conductive structure. The plurality of sensors are divided into two groups, namely a main sensor group and a redundant sensor group. When the main sensor group fails, the redundant sensor can be used to continue to detect the axial displacement change of the rotating shaft, thereby improving the fault recognition rate of the displacement sensor in the magnetic suspension bearing and extending the service life of the displacement sensor.

[0015] 2. The magnetic conductive structure and the pole are integrally formed into an integrated core, which does not require separate cores, thus reducing the number of assembly times. At the same time, compared with the separately assembled core, the integrated core structure is processed as a whole, which is easy to process and manufacture, saving production costs, and avoiding the measurement errors introduced by the traditional displacement sensor due to the asymmetric installation of the independent core.

[0016] 3. A convex ring is provided between the rotating shaft and the pole to prevent the rotating shaft from deviating in the radial direction due to interference from external factors, and to prevent the rotating shaft from colliding with components such as the pole when the rotating shaft is unstable. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the utility model.

[0018] Figure 2 It is an explosion diagram of the utility model.

[0019] Figure 3 This is the main view of the core.

[0020] Figure 4 It is a cross-sectional view of the utility model.

[0021] Figure 5 Schematic diagram of each sensor.

[0022] Among them: 1, support base 2, fixing hole 3, magnetic conductive structure 4, pole 5, winding 6, skeleton 7, connecting ring 8, convex ring 9, rotating shaft 10, connecting groove 11, integrated iron core 12, accommodating groove 13, a sensor 14, b sensor 15, c sensor 16, d sensor 17, e sensor 18, f sensor 19, g sensor 20, h sensor. DETAILED DESCRIPTION

[0023] Figures 1 to 5 It is the best embodiment of the utility model, and the following Figures 1 to 5 The utility model is further described.

[0024] like Figure 1~2 As shown, a displacement sensor of a magnetic bearing of the utility model comprises a support seat 1, a rotating shaft 9 and a displacement sensor assembly. The displacement sensor assembly is fixedly mounted on one side of the support seat 1. The two support seats 1 are spaced apart and symmetrically arranged. The two displacement sensor assemblies are arranged opposite to each other. A channel for the rotating shaft 9 to pass through is arranged in the middle of the displacement sensor assembly. The two ends of the rotating shaft 9 are respectively suspended in the middle of the two displacement sensor assemblies. The displacement sensor assembly can detect radial displacement changes of the rotating shaft 9.

[0025] The displacement sensor assembly includes an annular magnetic conductive structure 3 and a pole 4. A plurality of even-numbered poles 4 are evenly arranged in the inner circle of the magnetic conductive structure 3. The poles 4 are arranged along the axis of the magnetic conductive structure 3. The end of the rotating shaft 9 passes through the center position of the pole 4. A skeleton 6 is arranged on each pole 4. The winding 5 is wound on the pole 4 through the skeleton 6. Two adjacent poles 4 form a sensor. The coil simultaneously winds the two adjacent poles 4 inside and energizes them, thereby generating a magnetic field. At least eight sensors that are multiples of 4 are formed in the inner circle of the magnetic conductive structure 3. The sensors arranged at intervals form a main sensor group, and the remaining sensors form a redundant sensor group. The main sensor group and the redundant sensor group are respectively connected to the power supply device. When the main sensor group fails, the main sensor group transmits a signal to the controller, and the controller then energizes the redundant sensor. The redundant sensor is used to continue to detect the axial displacement change of the rotating shaft 9, thereby improving the fault recognition rate of the displacement sensor in the magnetic suspension bearing and extending the service life of the device.

[0026] like Figure 3As shown, in the present embodiment, the magnetic conductive structure 3 and a plurality of poles 4 are integrally formed to form an integrated core 11. The integrated core 11 does not require separate cores, which can reduce the number of assembly times. At the same time, compared with the separately assembled cores, the integrated core 11 is processed as a whole, which is easy to process and manufacture, saves production costs, and improves the production and processing efficiency of the device; and it can avoid the measurement error introduced by the traditional inductive displacement sensor due to the asymmetric installation of the independent core, and improve the zero-point residual voltage problem caused by this.

[0027] In this embodiment, sixteen poles 4 are evenly arranged in the inner circle of the magnetic conductive structure 3, a skeleton 6 is fixed on each side of the pole 4, and the winding 5 is wound on the pole 4 through the skeleton 6. The pole 4, the winding 5 and the skeleton 6 together constitute a complete magnetic pole, and two adjacent poles 4 constitute a sensor. Therefore, in this embodiment, eight sensors are formed in the inner circle of the magnetic conductive structure 3, and four sensors along the first radial direction and the second radial direction constitute a main sensor group. The first radial direction and the second radial direction are perpendicular to each other, and the four sensors between two adjacent main sensors constitute a redundant sensor group.

[0028] like Figure 4 As shown, a connecting ring 7 is protrudingly provided on one side of the support seat 1, and the connecting ring 7 and the support seat 1 are integrally arranged. A connecting groove 10 is correspondingly provided on one side of the magnetic conductive structure 3, and the connecting groove 10 is also annular. When the magnetic conductive structure 3 and the support seat 1 are connected, the connecting ring 7 is inserted into the connecting groove 10, so that the connection between the support seat 1 and the magnetic conductive structure 3 is faster and more stable. At the same time, a fixing boss is provided on the other side of the support seat 1, and a fixing hole 2 is opened on the fixing boss. The support seat 1 can be fixed by passing a bolt through the fixing hole 2.

[0029] A convex ring 8 is protruded on one side of the support seat 1. The outer diameter of the convex ring 8 is smaller than the inner diameter of the circle formed at the end of each pole 4. The inner diameter of the convex ring 8 is larger than the outer diameter of the rotating shaft 9. The rotating shaft 9 is suspended in the convex ring 8, and the outer diameter of the rotating shaft 9 corresponding to the convex ring 8 is larger than the outer diameter of the rotating shaft 9 at other positions. The convex ring 8 is closer to the pole 4 and the gap between the convex ring 8 and the pole 4 is extremely small. The convex ring 8 is provided to prevent the rotating shaft 9 from being offset in the radial direction due to interference from external factors, and at the same time, it can also avoid collision and contact with components such as the pole 4 when the rotating shaft 9 is in an unstable state.

[0030] A receiving groove 12 is provided on one side of the support seat 1 close to the shaft 9. The receiving groove 12 is circular and has a diameter smaller than the diameter of the convex ring 8. The end of the shaft 9 is suspended in the receiving groove 12, and a gap is provided between the end of the shaft 9 and the support seat 1 to prevent the shaft 9 from colliding with the support seat 1. The magnetic conductive structure 3 and the pole 4 are both made of magnetic conductive material.

[0031] like Figure 5As shown, in this embodiment, two main displacement sensors are respectively arranged in the x-axis and y-axis directions, and the main sensor group includes a sensor 13, b sensor 14, c sensor 15 and d sensor 16. In order to realize fault-tolerant control, two redundant displacement sensors are respectively arranged in the directions with an angle of θ with the positive semi-axis and the negative semi-axis of the x-axis, and the redundant sensor group includes e sensor 17, f sensor 18, g sensor 19 and h sensor 20. When each sensor in the main sensor group works normally, |Ua=Ub|, |Uc=Ud| (wherein Ua represents the voltage of a sensor 13, Ub represents the voltage of b sensor 14, and the rest are similar), and normal displacement detection can be realized without redundant sensors. When any sensor in the main sensor group fails and differential displacement measurement in the corresponding direction cannot be realized, the controller controls the redundant sensor group to be energized and continue to detect the axial displacement change of the rotating shaft 9.

[0032] And the device can determine the faulty sensor by combining the redundant sensor output voltage value with trigonometric function:

[0033] For example: When sensor a 13 fails:

[0034] ;

[0035] When the b sensor 14 fails:

[0036] ;

[0037] When both sensor a 13 and sensor b 14 fail:

[0038] .

[0039] When the utility model is in use, the armature is arranged on the rotating shaft 9 and rotates with the rotating shaft 9. When the alternating current passes through the coil, a magnetic field is generated to magnetize the integrated iron core 11. The armature is magnetized under the action of the magnetic field, thereby forming a complete magnetic circuit. The four main sensors arranged at intervals detect the displacement change of the rotating shaft 9 after power is turned on. When the position of the armature changes (i.e., displacement occurs), the magnetic resistance of the magnetic circuit will change accordingly. According to the law of electromagnetic induction, the change in magnetic resistance will cause the inductance of the coil to change. The detection circuit can convert the change in inductance into the change in voltage or current signal, and then the size and direction of the displacement can be accurately measured according to this change. When there is a sensor failure in the main sensor group, the controller determines the failure of the main sensor and energizes the redundant sensor group to continue to replace the main sensor group to detect the displacement change of the rotating shaft 9. The utility model improves the fault recognition rate of the displacement sensor in the magnetic suspension bearing and extends the service life of the displacement sensor.

[0040] The above is only the preferred embodiment of the utility model, and does not limit the utility model in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the utility model without departing from the technical solution of the utility model still belongs to the protection scope of the technical solution of the utility model.

Claims

1. A displacement sensor for a magnetic bearing, characterized in that: The device comprises a support seat (1), a rotating shaft (9) and a displacement sensor assembly, wherein the displacement sensor assembly is fixedly mounted on one side of the support seat (1), two groups of support seats (1) and displacement sensor assemblies are symmetrically arranged and spaced apart, a passage for the rotating shaft (9) to pass through is arranged in the middle of the displacement sensor assembly, and two ends of the rotating shaft (9) are respectively suspended in the middle of the two displacement sensor assemblies; The displacement sensor assembly comprises an annular magnetic conductive structure (3) and a pole (4). A plurality of poles (4) are evenly arranged in the inner circle of the magnetic conductive structure (3). A frame (6) is arranged on each pole (4). A winding (5) is wound on the pole (4) through the frame (6). Two adjacent poles (4) form a sensor. At least eight sensors that are multiples of 4 are formed in the inner circle of the magnetic conductive structure (3). The sensors arranged at intervals form a main sensor group, and the remaining sensors form a redundant sensor group. The main sensor group and the redundant sensor group are respectively connected to a power supply device.

2. The displacement sensor of a magnetic bearing according to claim 1, characterized in that: Sixteen poles (4) are evenly arranged on the inner ring of the magnetic conductive structure (3), and eight sensors are formed on the inner ring of the magnetic conductive structure (3). Four sensors along a first radial direction and a second radial direction form a main sensor group. The first radial direction and the second radial direction are perpendicular to each other, and four sensors between two adjacent main sensors form a redundant sensor group.

3. The displacement sensor of a magnetic bearing according to claim 1, characterized in that: The magnetic conductive structure (3) and the plurality of poles (4) are integrally formed.

4. The displacement sensor of a magnetic bearing according to claim 1, characterized in that: A connecting ring (7) is protrudingly provided on one side of the support seat (1), and a connecting groove (10) is correspondingly provided on one side of the magnetic conductive structure (3), and the connecting ring (7) is inserted into the connecting groove (10).

5. The displacement sensor of a magnetic bearing according to claim 1, characterized in that: A receiving groove (12) is provided on one side of the support seat (1) close to the rotating shaft (9), the end of the rotating shaft (9) is suspended in the receiving groove (12), and a gap is provided between the end of the rotating shaft (9) and the support seat (1).

6. The displacement sensor of a magnetic bearing according to claim 1, characterized in that: A convex ring (8) is protrudingly provided on one side of the support seat (1); the outer diameter of the convex ring (8) is smaller than the inner diameter of the circle formed by the ends of each pole (4); the inner diameter of the convex ring (8) is larger than the outer diameter of the rotating shaft (9); and the rotating shaft (9) is suspended in the convex ring (8).

7. The displacement sensor of a magnetic bearing according to claim 6, characterized in that: The outer diameter of the rotating shaft (9) at a position corresponding to the convex ring (8) is greater than the outer diameter of other positions of the rotating shaft (9).

8. The displacement sensor of a magnetic bearing according to claim 1, characterized in that: The magnetic conductive structure (3) and the pole (4) are both made of magnetic conductive materials.

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