Permanent magnet excitation structure and steel wire rope magnetic flux leakage detection device

Abstract

The utility model provides a permanent magnet excitation structure and a steel wire rope magnetic flux leakage detection device, the permanent magnet excitation structure comprises two annular permanent magnets and an annular armature, the two ends of the annular armature are provided with annular eave bodies; the annular permanent magnet can be embedded into the inner side of the eave body, the outer surface of the annular permanent magnet is attached to the inner surface of the eave body, the inner wall face of the annular permanent magnet and the inner wall face of the annular armature are both of a cylindrical face structure and are the same in diameter, and the axial length of the annular armature is the same as the axial length of the eave body. The magnetic field outside the permanent magnet excitation structure is reduced, the permanent magnet excitation structure is effectively lightened, and the permanent magnet excitation structure is convenient to transport and use.

Description

Technical Field

[0001] The utility model relates to the technical field of wire rope magnetic leakage detection, in particular to a permanent magnet excitation structure and a wire rope magnetic leakage detection device. Background Art

[0002] The usual permanent magnet excitation structure of the wire rope is two annular permanent magnets plus an annular armature, the two annular permanent magnets are on both sides of the annular armature, or the two annular permanent magnets are on the inner side of the annular armature, but both structures have disadvantages:

[0003] When two annular permanent magnets are arranged on both sides of the annular armature, as shown in the attached Figure 3 As shown in A, there will be a strong magnetic field on the radial outside of the permanent magnet exciter. If a circuit board is installed near the exciter, the magnetic field will seriously interfere with the normal operation of the circuit (such as a power supply containing a transformer);

[0004] When two annular permanent magnets are arranged on the inner sides of both ends of the annular armature, as shown in the attached Figure 3 As shown in B, the permanent magnet excitation structure will be large in size and heavy in weight, making it inconvenient to transport and use. Utility Model Content

[0005] In view of the deficiencies in the prior art, the utility model provides a permanent magnet excitation structure and a wire rope magnetic leakage detection device, which reduce the magnetic flux in the external air, have lighter gravity, and are easy to transport and use.

[0006] According to an embodiment of the utility model, a permanent magnet excitation structure includes two annular permanent magnets and an annular armature, both ends of the annular armature are provided with annular eaves, the annular permanent magnet can be embedded into the inner side of the eaves and make the outer surface of the annular permanent magnet fit with the inner surface of the eaves, the inner wall surfaces of the annular permanent magnet and the annular armature are both cylindrical structures with the same diameter, and the axial length of the annular armature is the same as the axial length of the eaves.

[0007] Preferably, the outer wall surface of the eaves body is a cylindrical surface structure having the same outer diameter as the annular armature.

[0008] Further preferably, the outer wall surface of the annular permanent magnet is a cylindrical surface structure, and the inner wall surface of the eaves body is a cylindrical surface structure with the same outer diameter as the annular permanent magnet.

[0009] Further preferably, each of the annular permanent magnets is composed of at least two lobes, and the annular armature is composed of at least two lobes.

[0010] Further preferably, at least one through hole is provided on the side wall of the annular armature.

[0011] Still further preferably, the through hole is arranged radially along the annular armature.

[0012] According to an embodiment of the utility model, a wire rope magnetic leakage detection device is also provided, comprising the above-mentioned permanent magnet excitation structure.

[0013] Compared with the prior art, the utility model has the following beneficial effects:

[0014] Compared with directly setting two annular permanent magnets at both ends of the annular armature, the outer wall surfaces of the annular permanent magnets at both ends of the utility model are shielded by the eaves. According to the "principle of minimum magnetic resistance", the magnetic flux always takes the path with the minimum magnetic resistance (maximum magnetic permeability), and the magnetic lines of force outside the magnet always point from the n-pole to the s-pole. Since the magnetic permeability of iron is much greater than that of air, most of the magnetic flux outside the magnet will first pass through the armature, and only a small amount will pass through the air. The magnetic flux in the radial outer air is reduced, which plays a role in shielding the magnetic field and reduces the impact of the magnetic field on the circuit;

[0015] The inner walls of the annular permanent magnets at both ends are exposed inwards, so that the magnetic flux can preferentially pass through the steel wire rope and saturate magnetize the steel wire rope.

[0016] Compared with the prior art in which two annular permanent magnets are arranged on the inner sides of the two ends of the annular armature and there is a passing space of the same size on the inner side of the excitation structure, the inner diameter of the annular armature in the prior art is the same as the outer diameter of the annular permanent magnet, while the inner diameter of the annular armature in the utility model is the same as the inner diameter of the annular permanent magnet. On the premise of ensuring that the annular armature has the same thickness, the annular armature in the utility model is smaller in size and lighter in weight, and will be more convenient to transport and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The utility model is a schematic diagram of a permanent magnet excitation structure.

[0018] Figure 2 This is a schematic diagram of magnetic field strength analysis of a permanent magnet excitation structure of the utility model.

[0019] Figure 3 It is a schematic diagram of the matching structure of an annular permanent magnet and an annular armature in the permanent magnet excitation structure of the prior art and the utility model.

[0020] In the above drawings: 1. annular permanent magnet; 2. annular armature; 3. eaves body; 4. through hole. DETAILED DESCRIPTION

[0021] The technical solution of the present utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0022] Embodiment 1:

[0023] like Figure 1As shown, a permanent magnet excitation structure comprises two annular permanent magnets 1 and an annular armature 2, an annular eaves 3 are provided at both ends of the annular armature 2, the annular permanent magnet 1 can be embedded into the inner side of the eaves 3 so that the outer surface of the annular permanent magnet 1 fits with the inner surface of the eaves 3, the matching clearance between the annular permanent magnet 1 and the eaves 3 is zero, the inner wall surfaces of the annular permanent magnet 1 and the annular armature 2 are both cylindrical structures with the same diameter, so that after the annular permanent magnet 1 and the annular armature 2 are installed, the channel on the inner side of the permanent magnet excitation structure is smooth, which facilitates the smooth entry of the steel wire rope into the permanent magnet excitation structure, the axial length of the annular armature 2 is the same as the axial length of the eaves 3, and after the permanent magnet excitation structure is assembled, the end of the annular armature 2 is flush with the end of the eaves 3, so that the two end faces of the permanent magnet excitation structure are smoother;

[0024] The outer wall of the annular permanent magnet is blocked by the eaves 3. According to the "principle of minimum magnetic resistance", the magnetic flux always takes the path with the minimum magnetic resistance, and the magnetic lines of force outside the magnet always point from the n-pole to the s-pole. Since the magnetic permeability of iron is much greater than that of air, most of the magnetic flux outside the annular permanent magnet 1 will preferentially pass through the annular armature 2, and only a small amount will pass through the air.

[0025] according to Figure 2 It can be seen that the eaves 3 can effectively reduce the magnetic flux in the radially outer air, play a role in shielding the magnetic field, and reduce the impact of the magnetic field on the circuit;

[0026] The outer wall surface of the eaves 3 is a cylindrical surface structure with the same outer diameter as the annular armature 2, the outer wall surface of the annular permanent magnet 1 is a cylindrical surface structure, and the inner wall surface of the eaves 3 is a cylindrical surface structure with the same outer diameter as the annular permanent magnet 1;

[0027] according to Figure 3 It can be seen from the matching structure of the annular permanent magnet 1 and the annular armature 2 in the prior art B and the utility model C that, under the premise of ensuring that the permanent magnet excitation structure has the same diameter of the entry space and the annular permanent magnet 1 has the same thickness, the present solution has a smaller volume and lighter weight;

[0028] In order to facilitate the combined installation of the annular permanent magnet 1 and the annular armature 2, in a further embodiment, each of the annular permanent magnets 1 is composed of at least two lobes, and the annular armature 2 is composed of at least two lobes;

[0029] In order to facilitate circuit routing, in a further embodiment, at least one through hole 4 is provided on the side wall of the annular armature 2 , and the through hole 4 is arranged radially along the annular armature 2 .

[0030] Embodiment 2:

[0031] A wire rope magnetic flux leakage detection device includes a permanent magnet excitation structure described in the first embodiment.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A permanent magnet excitation structure, comprising two annular permanent magnets (1) and an annular armature (2), characterized in that: Both ends of the annular armature (2) are provided with an annular eaves (3); the annular permanent magnet (1) can be embedded into the inner side of the eaves (3) so that the outer surface of the annular permanent magnet (1) fits the inner surface of the eaves (3); the inner wall surfaces of the annular permanent magnet (1) and the annular armature (2) are both cylindrical structures with the same diameter; the axial length of the annular armature (2) is the same as the axial length of the eaves (3).

2. A permanent magnet excitation structure according to claim 1, characterized in that: The outer wall surface of the eaves body (3) is a cylindrical surface structure having the same outer diameter as the annular armature (2).

3. A permanent magnet excitation structure according to claim 1, characterized in that: The outer wall surface of the annular permanent magnet (1) is a cylindrical surface structure, and the inner wall surface of the eaves body (3) is a cylindrical surface structure having the same outer diameter as the annular permanent magnet (1).

4. A permanent magnet excitation structure according to any one of claims 1 to 3, characterized in that: Each of the annular permanent magnets (1) is composed of at least two lobes, and the annular armature (2) is composed of at least two lobes.

5. A permanent magnet excitation structure according to claim 4, characterized in that: At least one through hole (4) is provided on the side wall of the annular armature (2).

6. A permanent magnet excitation structure according to claim 5, characterized in that: The through hole (4) is arranged radially along the annular armature (2).

7. A wire rope magnetic flux leakage detection device, characterized in that: It includes a permanent magnet excitation structure as described in claim 6.

Images