Displacement sensor fixing device, magnetic bearing stator and magnetic suspension molecular pump

Abstract

The utility model relates to the technical field of molecular pumps, in particular to a displacement sensor fixing device, a magnetic bearing stator and a magnetic suspension molecular pump. Comprising an annular fixing framework, and one side face of the fixing framework is provided with a jacking ring concentric with the fixing framework; the number of the fixing assemblies is four, the displacement sensors correspond to the fixing assemblies in a one-to-one mode, the four fixing assemblies are evenly arranged on the fixing framework with the circle center of the fixing framework as the center and located on the different sides of the jacking ring, and the fixing assemblies are suitable for fixing the displacement sensors to the fixing framework; the fixing assembly comprises a fixing ring set which is composed of a plurality of coaxial fixing rings and fixedly connected with the fixing framework, and the displacement sensor is sleeved with the fixing ring set. Compared with an existing long-face injection molding part, the fixing ring has the advantages that the shrinkage amount of a single fixing ring is small, the displacement sensor is small in deviation after being positioned through a tool, and the detection requirement for the rotor can be met.

Description

Technical Field

[0001] The utility model relates to the technical field of molecular pumps, in particular to a displacement sensor fixing device, a magnetic bearing stator and a magnetic suspension molecular pump. Background Art

[0002] In order to ensure the stable suspension of the rotor in the magnetic bearing, a displacement sensor is generally used to detect the movement and rotation of the rotor. First, the position and angle of the displacement sensor on the fixed seat formed by engineering injection molding such as PPS is adjusted through tooling, and then the displacement sensor is fixed on the fixed seat.

[0003] The existing method of fixing the displacement sensor is to set an injection molded part with a long surface on the fixing seat to wrap the side of the displacement sensor as a whole. In this way, the long surface is in close contact with the side of the displacement sensor, but because the long surface of the injection molded part will shrink, it is difficult for the inside and outside of the injection molded part to shrink in unison, resulting in a relatively large deviation in the actual position of the displacement sensor even after the tooling is adjusted, affecting the stable suspension of the rotor. Utility Model Content

[0004] Therefore, the utility model aims to overcome the technical problems in the prior art, thereby providing a displacement sensor fixing device, a magnetic bearing stator and a magnetic suspension molecular pump.

[0005] The utility model provides a displacement sensor fixing device, which is applied to a magnetic bearing, and includes:

[0006] The fixed frame is annular, and a tightening ring concentric with the fixed frame is provided on one side surface of the fixed frame;

[0007] There are four sets of fixed components, the displacement sensors correspond to the fixed components one by one, the four sets of fixed components are evenly arranged on the fixed frame and on the opposite side of the top tightening ring with the center of the fixed frame as the center, and the fixed components are suitable for fixing the displacement sensors on the fixed frame;

[0008] The fixing assembly comprises a fixing ring group consisting of a plurality of coaxial fixing rings and fixedly connected to the fixing frame, and the displacement sensor is sleeved inside the fixing ring group.

[0009] Furthermore, the central axes of the four groups of fixed ring groups are located in the same plane parallel to the fixed frame, the central axes of two opposite fixed ring groups coincide, the central axes of two adjacent fixed ring groups are perpendicular, and the central axes of the four groups of fixed ring groups have an intersection and the intersection is located on the central axis of the fixed frame.

[0010] Furthermore, the number of the fixing rings in each fixing ring group is two.

[0011] Furthermore, the fixing assembly further comprises:

[0012] A threaded hole is provided on the top tightening ring and is opposite to the position of the displacement sensor;

[0013] A bolt, threadedly connected to the threaded hole;

[0014] When the bolt is screwed into the threaded hole, the bolt abuts against the side surface of the displacement sensor, which is suitable for tightening the displacement sensor onto the fixing ring.

[0015] Furthermore, a plurality of sealing exhaust holes are provided on the fixed frame.

[0016] A magnetic bearing stator, comprising:

[0017] The above-mentioned displacement sensor fixing device;

[0018] The stator core includes an annular base and a sector-shaped sheet, which is arranged on the same side of the fixed ring on the fixed frame;

[0019] A bearing coil is sleeved on the fan-shaped piece;

[0020] There are eight sector-shaped pieces, which are evenly and fixedly arranged on the inner side surface of the annular base. The annular base is coaxial with the fixed frame. The bearing coil is provided with a winding.

[0021] Furthermore, a boss is provided on the upper end surface of the bearing coil close to the annular base, and a limiting hole matched with the boss is provided on the fixed frame, and the boss is inserted into the limiting hole.

[0022] Furthermore, there is a gap between two adjacent bearing coils, and each displacement sensor faces the gap between the two bearing coils.

[0023] Furthermore, the end surface of the bearing coil close to the annular base is provided with two lead-out grooves.

[0024] A magnetic levitation molecular pump, comprising:

[0025] A magnetic bearing stator as described above;

[0026] Pump body and rotor;

[0027] There are two magnetic bearing stators, which are coaxially and symmetrically arranged in the pump body, and the rotor is arranged on the inner sides of the two magnetic bearing stators.

[0028] The technical solution of the utility model has the following advantages:

[0029] The utility model provides a displacement sensor fixing device, a magnetic bearing stator and a magnetic suspension molecular pump. Compared with the existing long-surface injection molded parts, the shrinkage of a single fixing ring is relatively small. After being positioned by the tooling, the displacement sensor has a small offset, which can meet the detection requirements for the rotor. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 This is a schematic diagram of the structure of the displacement sensor fixing device of the utility model;

[0032] Figure 2 This is a schematic diagram of the position of the fixing ring of the utility model;

[0033] Figure 3 This is a schematic diagram of the bolt position of the utility model;

[0034] Figure 4 This is a schematic diagram of the stator structure of the magnetic bearing of the utility model;

[0035] Figure 5 This is a schematic diagram of the stator core structure of the utility model;

[0036] Figure 6 This is a schematic diagram of the bearing coil structure of the utility model.

[0037] Description of reference numerals;

[0038] 1. Fixed frame; 2. Tightening ring; 3. Displacement sensor; 4. Fixed ring; 5. Threaded hole; 6. Bolt; 7. Potting exhaust hole; 8. Stator core; 9. Ring base; 10. Fan-shaped piece; 11. Bearing coil; 12. Boss; 13. Limit hole; 14. Lead-out wire slot. DETAILED DESCRIPTION

[0039] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0040] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0041] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" 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 or an electrical 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.

[0042] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0043] Example

[0044] like Figures 1 to 6 A displacement sensor fixing device, a magnetic bearing stator, and a magnetic suspension molecular pump are shown in detail. The displacement sensor fixing device is applied to a magnetic bearing and includes:

[0045] The fixed frame 1 is annular, and a tightening ring 2 concentric with the fixed frame 1 is provided on one side of the fixed frame 1, wherein the middle part between the fixed frame 1 and the fixed ring 4 is used to pass the rotor;

[0046] There are four sets of fixed components, and the displacement sensors 3 correspond to the fixed components one by one. The four sets of fixed components are evenly arranged on the fixed frame 1 and on the opposite side of the top tightening ring 2 with the center of the fixed frame 1 as the center. The fixed components are suitable for fixing the displacement sensors 3 on the fixed frame 1;

[0047] It should be noted that there are eight displacement sensors 3 in the magnetic bearing, which are used to detect the rotation of the rotor around a fixed point and the movement on the plane of the fixed frame 1. The magnetic bearing includes two symmetrical stators, and the displacement sensor fixing device of the present application is a part of one of the stators.

[0048] The fixing assembly includes a fixing ring group composed of a plurality of coaxial fixing rings and fixedly connected to the fixing frame 1. The displacement sensor 3 is mounted in the fixing ring group. The fixing frame 1, the tightening ring 2 and the fixing assembly are all engineering injection molding parts such as PPS. The injection molding parts made of engineering materials are resistant to high temperatures. Taking PPS as an example, the melting point is basically above 280°C, which meets the working conditions. Secondly, the overall mass is reduced, and the use strength is relatively high, which meets the positioning requirements.

[0049] Compared with the existing long-surface injection molded parts, the shrinkage of a single fixing ring 4 is relatively small. After being positioned by the tooling, the displacement sensor 3 has a relatively small offset, which can meet the detection requirements for the rotor.

[0050] Furthermore, the central axes of the four sets of fixed ring groups are located in the same plane parallel to the fixed frame 1, the central axes of the two fixed ring groups at opposite positions overlap, the central axes of the two fixed ring groups at adjacent positions are perpendicular, and the central axes of the four fixed ring groups have an intersection and the intersection is located on the central axis of the fixed frame 1. It can be ensured that the displacement sensors 3 are located in the same plane, and the two relative displacement sensors 3 are perpendicular to the other two displacement sensors 3 and the central points overlap, and the front end surfaces of the two relative displacement sensors 3 are parallel to each other.

[0051] During tooling, a round rod can be installed in the middle position of the fixed frame 1. The round rod and the fixed frame 1 are clearance fit or transition fit. Then the displacement sensor 3 is installed in the fixed ring 4 of the fixed ring group so that the displacement sensor 3 abuts the round rod, and the tooling is completed.

[0052] Furthermore, the number of the fixing rings 4 in each fixing ring group is two, wherein the two fixing rings 4 can be sleeved on the two sides of the displacement sensor 3 , so as to conveniently fix the displacement sensor 3 .

[0053] Furthermore, the fixing assembly further comprises:

[0054] A threaded hole 5 is provided on the tightening ring 2 and is opposite to the position of the displacement sensor 3;

[0055] Bolt 6, threadedly connected to the threaded hole 5;

[0056] When the bolt 6 is screwed into the threaded hole 5, the bolt 6 abuts against the side of the displacement sensor 3, which is suitable for tightening the displacement sensor 3 onto the fixing ring 4. In order to prevent the bolt 6 from causing damage to the side of the displacement sensor 3, the bolt 6 can be a flat-end bolt 6. In order to prevent the bolt 6 from loosening, thread glue can be applied to the bolt 6 when the bolt 6 is screwed.

[0057] Furthermore, a plurality of potting exhaust holes 7 are provided on the fixed frame 1 .

[0058] A magnetic bearing stator, comprising:

[0059] The above-mentioned displacement sensor fixing device;

[0060] The stator core 8, including an annular base 9 and a sector piece 10, is arranged on the same side of the fixed ring 4 on the fixed frame 1;

[0061] A bearing coil 11 is mounted on the fan-shaped piece 10;

[0062] There are eight sector-shaped pieces 10 , which are evenly and fixedly arranged on the inner side of the annular base 9 . The annular base 9 is coaxial with the fixed frame 1 . The bearing coil 11 is provided with a winding.

[0063] Furthermore, the upper end surface of the bearing coil 11 close to the annular base 9 is provided with a boss 12, and the boss 12 may be rectangular, circular or irregular in shape, but the present embodiment is not limited thereto. The fixed skeleton 1 is provided with a limiting hole 13 adapted to the boss 12, and the boss 12 is inserted into the limiting hole 13. It should be noted that the boss 12 is inserted into the limiting hole 13, and the side surface of the fixed skeleton 1 is against the end surface of the bearing coil, and the distance between the annular base 9 and the fixed skeleton 1 is confirmed and fixed, so that there is a gap between the annular base 9 and the fixed skeleton 1, and the position of the displacement sensor 3 and the fan-shaped piece 10 and the bearing coil 11 is also limited.

[0064] Furthermore, there is a gap between two adjacent bearing coils 11, and each displacement sensor 3 faces the gap between the two bearing coils 11. The gap between the two bearing coils 11 can conveniently obtain the lead wires of the windings on the bearing coils 11 from the gap, and the lead wires of the windings can be collected in the gap between the annular base 9 and the fixed frame 1. The displacement sensor 3 faces the gap between the two bearing coils 11. In the present application, every two bearing coils 11 face a gap, and the lead wires of the displacement sensor 3 can be conveniently obtained, and can be collected in the gap between the annular base 9 and the fixed frame 1.

[0065] Furthermore, two lead-out wire grooves 14 are provided on the end surface of the bearing coil 11 close to the annular base 9, which can fix the lead-out wires of the winding and the lead-out wires of the displacement sensor 3 respectively.

[0066] A magnetic levitation molecular pump, comprising:

[0067] A magnetic bearing stator as described above;

[0068] Pump body and rotor;

[0069] There are two magnetic bearing stators, which are coaxially and symmetrically arranged in the pump body, and the rotor is arranged on the inner sides of the two magnetic bearing stators.

[0070] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention of the utility model.

Claims

1. A displacement sensor fixing device, applied to a magnetic bearing, characterized in that: include: The fixed frame (1) is annular, and a tightening ring (2) concentric with the fixed frame (1) is provided on one side surface of the fixed frame (1); The fixing components are four groups, the displacement sensors (3) correspond to the fixing components one by one, the four groups of fixing components are evenly arranged on the fixing frame (1) and on the opposite side of the tightening ring (2) with the center of the fixing frame (1) as the center, and the fixing components are suitable for fixing the displacement sensors (3) on the fixing frame (1); The fixing assembly comprises a fixing ring group composed of a plurality of coaxial fixing rings and fixedly connected to the fixing frame (1), and the displacement sensor (3) is sleeved inside the fixing ring group.

2. The displacement sensor fixing device according to claim 1, characterized in that: The central axes of the four sets of fixed ring groups are located in the same plane parallel to the fixed frame (1), the central axes of two fixed ring groups at opposite positions overlap, the central axes of two fixed ring groups at adjacent positions are perpendicular, and the central axes of the four sets of fixed ring groups have an intersection, and the intersection is located on the central axis of the fixed frame (1).

3. The displacement sensor fixing device according to claim 1, characterized in that: The number of the fixing rings (4) in each fixing ring group is two.

4. The displacement sensor fixing device according to claim 3, characterized in that: The fixing assembly also includes: A threaded hole (5) is arranged on the tightening ring (2) and is opposite to the position of the displacement sensor (3); A bolt (6) threadedly connected to the threaded hole (5); When the bolt (6) is threadedly connected to the threaded hole (5), the bolt (6) abuts against the side surface of the displacement sensor (3), which is suitable for tightening the displacement sensor (3) onto the fixing ring (4).

5. The displacement sensor fixing device according to claim 1, characterized in that: The fixed frame (1) is provided with a plurality of potting exhaust holes (7).

6. A magnetic bearing stator, characterized in that: include: The displacement sensor fixing device according to any one of claims 1 to 5; The stator core (8) comprises an annular base (9) and a sector piece (10), and is arranged on the same side of the fixed ring (4) on the fixed frame (1); A bearing coil (11) is sleeved on the sector sheet (10); There are eight sector-shaped pieces (10) which are evenly and fixedly arranged on the inner side of the annular base (9); the annular base (9) and the fixed frame (1) are coaxial; and a winding is arranged on the bearing coil (11).

7. The magnetic bearing stator according to claim 6, characterized in that: The upper end surface of the bearing coil (11) close to the annular base (9) is provided with a boss (12), and the fixed frame (1) is provided with a limiting hole (13) matched with the boss (12), and the boss (12) is inserted into the limiting hole (13).

8. The magnetic bearing stator according to claim 6, characterized in that: There is a gap between two adjacent bearing coils (11), and each displacement sensor (3) faces the gap between the two bearing coils (11).

9. The magnetic bearing stator according to claim 6, characterized in that: The end surface of the bearing coil (11) close to the annular base (9) is provided with two lead-out grooves (14).

10. A magnetic levitation molecular pump, characterized in that: include; A magnetic bearing stator as claimed in any one of claims 6 to 9; Pump body and rotor; There are two magnetic bearing stators, which are coaxially and symmetrically arranged in the pump body, and the rotor is arranged on the inner sides of the two magnetic bearing stators.

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