Composite detection device in bimetal pipeline

Abstract

The utility model relates to the technical field of metal pipeline detection devices, in particular to a composite detection device in a bimetal pipeline, which comprises a detection main shaft, a magnetic flux leakage probe is sleeved in the middle of the detection main shaft and fixedly connected with the detection main shaft, and a connecting shell is mounted at one end of the detection main shaft and fixedly connected with the detection main shaft. The connecting shell and the detection main shaft are clamped and fixed, an ultrasonic detection assembly is arranged at the outer end of the connecting shell, the ultrasonic detection assembly is fixedly connected with the connecting shell, and a feeding head is further fixedly installed at the outer end of the ultrasonic detection assembly. The magnetic flux leakage probe is fixedly mounted on the detection main shaft, and the ultrasonic detection assembly is mounted on the detection main shaft, so that composite detection use can be realized through cooperation of the magnetic flux leakage probe and the ultrasonic detection assembly when the detection main shaft needs to be used; therefore, more accurate detection can be realized through cooperation of different detection data.

Description

Technical Field

[0001] The utility model relates to the technical field of metal pipeline detection devices, in particular to a double-metal pipeline internal composite detection device. Background Art

[0002] A double-metal composite pipeline refers to a pipeline made by compounding two metal pipes with different materials. During production, since the outer diameter of the inner pipe is slightly smaller than the inner diameter of the outer pipe, they can be sleeved, and then mechanical compounding can be carried out by using interference methods such as explosion, rolling, expansion joint, pulling, and spinning. When detecting a double-metal composite pipeline, it is often more difficult than a single-metal pipeline.

[0003] The magnetic flux leakage method is one of the important means for non-destructive testing of metal pipelines. It judges the size of workpiece defects by measuring the leakage magnetic field intensity on the surface of a magnetized ferromagnetic material workpiece. The detection principle of the magnetic flux leakage method requires that the object to be measured has good magnetic flux characteristics. When the local magnetic flux of the object to be measured is saturated, the two poles of the magnet and the object to be measured form a closed magnetic field. If the medium inside the object to be measured is evenly distributed, without voids, internal and external defects, it is considered that no magnetic flux passes through the outer wall under ideal conditions.

[0004] The existing Chinese patent with the publication number CN209624474U discloses a pipeline magnetic flux leakage detection device, including a magnetic probe, a mileage wheel, a driving wheel, a leather sleeve and a connecting piece. A driving wheel is arranged at the front end of the magnetic probe, a mileage wheel is arranged at the rear end of the magnetic probe, the magnetic probe and the driving wheel are connected by a connecting piece, the magnetic probe and the mileage wheel are connected by a connecting piece, and leather sleeves are arranged at the front and rear ends of the magnetic probe, the mileage wheel and the driving wheel.

[0005] In view of the above related technologies, it is found that when the existing pipeline magnetic flux leakage detection device detects a metal pipeline, especially a composite metal pipeline, it can only be detected by a single magnetic flux leakage method. When detecting multi-layer or complex pipelines, detection deviation or abnormal detection is likely to occur. Content of the Utility Model

[0006] The utility model solves the problems in the related technologies and provides a double-metal pipeline internal composite detection device.

[0007] In order to solve the above technical problems, the utility model is realized through the following technical solutions:

[0008] A dual-metal pipeline internal composite detection device includes a detection main shaft. A magnetic flux leakage probe is sleeved in the middle of the detection main shaft, and the magnetic flux leakage probe is fixedly connected to the detection main shaft. A connection shell is installed at one end of the detection main shaft, and the connection shell is snap-fitted and fixed to the detection main shaft. An ultrasonic detection component is arranged at the outer end of the connection shell, and the ultrasonic detection component is fixedly connected to the connection shell. A feed head is also fixedly installed at the outer end of the ultrasonic detection component.

[0009] By adopting the above technical solution, by sleeving a magnetic flux leakage probe in the middle of the detection main shaft, it is convenient to perform stable magnetic flux leakage detection through the magnetic flux leakage probe after the device is placed in the metal pipeline. At the same time, by installing a connection shell at one end of the detection main shaft, it is convenient to fixedly install the ultrasonic detection component through the connection shell. In this way, during the detection process, the ultrasonic detection component can assist the magnetic flux leakage probe to achieve composite detection of the pipeline. After detection, the situation of the metal pipeline can be analyzed by combining the magnetic flux leakage detection data and the ultrasonic detection data. At the same time, by fixedly installing a feed head at the outer end of the ultrasonic detection component, it is convenient for the device to move better inside the pipeline during the detection process.

[0010] As a preferred solution, the detection main shaft includes a shaft rod part, a connection flange and a positioning seat. The connection flange and the positioning seat are respectively arranged at both ends of the shaft rod part, and both the connection flange and the positioning seat are fixedly connected to the shaft rod part.

[0011] By adopting the above technical solution, by setting the structure of the detection main shaft to ensure that the connection flange and the positioning seat are arranged at both ends of the shaft rod part during use, the connection flange can be used to connect with the driving device during installation, which is convenient for the detection device to move and detect in the pipeline. At the same time, the setting of the positioning seat facilitates the positioning and installation of the connection shell.

[0012] As a preferred solution, the positioning seat includes a conical head and a limiting block. The limiting blocks are symmetrically arranged on the outer side surface of the conical head, and the limiting blocks are integrally formed with the conical head.

[0013] By adopting the above technical solution, by setting the structure of the positioning seat to ensure that the conical head can be stably inserted into the connection shell for quick installation during installation, and at the same time, by setting the limiting blocks, it is ensured that the installation in the connection shell is more stable.

[0014] As a preferred solution, the connection shell includes a shell tube, an outer expansion frame and a clamping ring. The outer expansion frames are symmetrically arranged on the outer side surface of the shell tube, and the outer expansion frames are integrally formed with the shell tube. The clamping ring is rotatably installed on the outer expansion frame.

[0015] By adopting the above technical solution, the structure of the connecting shell is set to ensure that the shell tube is used to cooperate with the conical head for connection, and an inner groove with the same shape as the conical head is arranged inside the shell tube to ensure that the conical head is more stable after being installed in the shell tube. At the same time, a pair of symmetrically outward-expanded frames are used to facilitate the stable installation of the snap ring, ensuring that the snap ring can be rotatably installed between the two outward-expanded frames. In this way, when the conical head is inserted into the shell tube, the conical head can be limited and locked by rotating the snap ring.

[0016] As a preferred solution, limiting grooves for installing limiting blocks are symmetrically formed on the inner side surface of the shell tube, and a support spring for supporting the rotation of the snap ring is fixedly installed at the outer end of the shell tube.

[0017] By adopting the above technical solution, by symmetrically forming limiting grooves on the inner side surface of the shell tube, it is convenient to quickly position and install the conical head through the limiting blocks when installing the conical head. At the same time, by setting the support spring, the snap ring is driven to rotate, facilitating the stable locking of the conical head by the snap ring.

[0018] As a preferred solution, the ultrasonic detection assembly includes a detection disc, an installation shell, and a detection head. The installation shells are uniformly arranged on the outer side surface of the detection disc and are fixedly connected to the detection disc.

[0019] By adopting the above technical solution, through the structural setting of the ultrasonic detection assembly, it is ensured that several installation shells can be arranged on the detection disc during use, and then the detection head can be conveniently inserted and installed through the installation shells, making it easy for the detection head to stably detect the metal pipeline.

[0020] As a preferred solution, engaging grooves for positioning and inserting the installation shells are uniformly formed on the outer side surface of the detection disc, and wire discharge grooves communicating with the engaging grooves are uniformly formed along the circumferential direction on one end surface of the detection disc.

[0021] By adopting the above technical solution, by uniformly forming engaging grooves on the outer side surface of the detection disc, the installation shells can be directly positioned and inserted into the engaging grooves during use, making it easy for quick installation. At the same time, through the setting of the wire discharge grooves, it is ensured that the detection head can be stably wired after installation.

[0022] As a preferred solution, the installation shell includes a top shell part and an inserting shell part. The inserting shell part is arranged on the lower end surface of the top shell part and is integrally formed with the top shell part.

[0023] By adopting the above technical solution, through the structural setting of the installation shell, it is ensured that the top shell part can be connected by inserting the inserting shell part into the engaging groove during use, and the lower end surface of the inserting shell part is an open structure, making it easy for the detection head to better perform wire arrangement operations.

[0024] As a preferred solution, the feeding head includes a disk plate, a wheel frame group and a main head shell. The wheel frame group is evenly installed on the outer side surface of the disk plate, and the main head shell is fixedly installed at the center of the disk plate. Both the wheel frame group and the main head shell are fixedly connected to the disk plate.

[0025] By adopting the above technical solution, the structure of the feeding head is set to ensure that the wheel frame group and the main head shell are arranged on the disk plate. In this way, when in use, the inner side surface of the pipeline can be stably supported by the wheel frame group, and at the same time, the main head shell can ensure better advancement in the pipeline.

[0026] Compared with the prior art, the beneficial effect of the present utility model is that in this application, a magnetic flux leakage probe is fixedly installed on the detection main shaft, and an ultrasonic detection component is installed on the detection main shaft. In this way, when in need of use, the magnetic flux leakage probe and the ultrasonic detection component can be cooperated to realize composite detection use, and more accurate detection can be realized through the cooperation of different detection data. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is the overall structural schematic diagram of the present utility model;

[0028] Figure 2 is the three-dimensional view of the cooperation between the detection main shaft and the magnetic flux leakage probe of the present utility model;

[0029] Figure 3 is the exploded structural schematic diagram of the connection shell of the present utility model;

[0030] Figure 4 is the structural schematic diagram of the ultrasonic detection component of the present utility model;

[0031] Figure 5 is Figure 4 the exploded structural schematic diagram of the device shown;

[0032] Figure 6 is the structural schematic diagram of the feeding head of the present utility model.

[0033] In the figure: 1, detection main shaft; 11, shaft rod part; 12, connection flange; 13, positioning seat; 131, conical head; 132, limit block; 2, magnetic flux leakage probe; 3, connection shell; 31, shell tube; 311, limit groove; 312, support spring; 32, outer expansion frame; 33, snap ring; 4, ultrasonic detection component; 41, detection disk; 411, engagement groove; 412, wire discharge groove; 42, installation shell; 421, top shell part; 422, insertion shell part; 43, detection head; 5, feeding head; 51, disk plate; 52, wheel frame group; 53, main head shell. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way restricts the present utility model and its application or use. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present utility model.

[0035] 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.

[0036] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present utility model. At the same time, it should be understood that for the sake of convenience of description, the dimensions 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 said technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed here, 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.

[0037] In the description of the present utility model, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal", and "top, bottom" are generally based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description. Without contrary instructions, 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, and thus cannot be construed as limiting the scope of protection of the present utility model; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0038] For ease of description, spatial relative terms such as "above", "over", "on the upper surface", "upper" etc. can be used here to describe the spatial positional relationship of a device or feature shown in the figure with other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figure for the device. For example, if the device in the attached drawing is inverted, a device described as "above" or "over" other devices or structures will then be positioned "below" or "under" other devices or structures. 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 interpretations are made for the spatial relative descriptions used here.

[0039] In addition, it should be noted that the use of terms such as "first" and "second" to define components is only for the convenience of differentiating the corresponding components. Without additional statements, the above terms have no special meanings, so they should not be construed as limiting the protection scope of the present utility model.

[0040] Embodiment 1

[0041] Refer to Figure 1 、 Figure 2 and Figure 3 As shown, a double-metal pipe internal composite detection device includes a detection main shaft 1. A magnetic flux leakage probe 2 is sleeved in the middle of the detection main shaft 1, and the magnetic flux leakage probe 2 is fixedly connected to the detection main shaft 1. One end of the detection main shaft 1 is provided with a connection shell 3, and the connection shell 3 is snap-fitted and fixed to the detection main shaft 1. An ultrasonic detection component 4 is arranged at the outer end of the connection shell 3, and the ultrasonic detection component 4 is fixedly connected to the connection shell 3. A feed head 5 is also fixedly installed at the outer end of the ultrasonic detection component 4. By sleeving the magnetic flux leakage probe 2 in the middle of the detection main shaft 1, it is convenient to achieve stable magnetic flux leakage detection through the magnetic flux leakage probe 2 after the device is placed in the metal pipe. At the same time, by installing the connection shell 3 at one end of the detection main shaft 1, it is convenient to fixedly install the ultrasonic detection component 4 through the connection shell 3. In this way, during the detection process, the ultrasonic detection component 4 can assist the magnetic flux leakage probe 2 to achieve composite detection of the pipe. After the detection, the magnetic flux leakage detection data and the ultrasonic detection data can be combined for analysis of the situation of the metal pipe. At the same time, by fixedly installing the feed head 5 at the outer end of the ultrasonic detection component 4, it is convenient for the device to move better inside the pipe during the detection process.

[0042] Refer to Figure 2As shown in the figure, the detection spindle 1 includes a shaft rod portion 11, a connecting flange 12 and a positioning seat 13. The connecting flange 12 and the positioning seat 13 are respectively arranged at both ends of the shaft rod portion 11, and both the connecting flange 12 and the positioning seat 13 are fixedly connected to the shaft rod portion 11. By setting the structure of the detection spindle 1, it is ensured that the connecting flange 12 and the positioning seat 13 are arranged at both ends of the shaft rod portion 11 during use. In this way, during installation, the connecting flange 12 can be used to connect with the driving device, facilitating the movement detection of the detection device in the pipeline. At the same time, the positioning seat 13 is provided to facilitate the positioning and installation of the connecting shell 3. The positioning seat 13 includes a conical head 131 and a limiting block 132. The limiting blocks 132 are symmetrically arranged on the outer side surface of the conical head 131, and the limiting blocks 132 are integrally formed with the conical head 131. By setting the structure of the positioning seat 13, it is ensured that during installation, the conical head 131 can be stably inserted into the connecting shell 3 for quick installation. At the same time, by setting the limiting blocks 132, it is ensured that the installation in the connecting shell 3 is more stable.

[0043] Refer to Figure 3 As shown in the figure, the connecting shell 3 includes a shell tube 31, an outer expansion frame 32 and a clamping ring 33. The outer expansion frames 32 are symmetrically arranged on the outer side surface of the shell tube 31, and the outer expansion frames 32 are integrally formed with the shell tube 31. The clamping ring 33 is rotatably installed on the outer expansion frames 32. By setting the structure of the connecting shell 3, it is ensured that the shell tube 31 is used to cooperate and connect with the conical head 131, and an inner groove with the same shape as the outer shape of the conical head 131 is provided inside the shell tube 31 to ensure that the conical head 131 is more stable after being installed in the shell tube 31. At the same time, through a pair of symmetric outer expansion frames 32, it is convenient for the clamping ring 33 to be stably installed, ensuring that the clamping ring 33 can be rotatably installed between the two outer expansion frames 32. In this way, after the conical head 131 is inserted into the shell tube 31, the conical head 131 can be limited and locked by rotating the clamping ring 33. Symmetric limiting grooves 311 for installing the limiting blocks 132 are provided on the inner side surface of the shell tube 31, and a support spring 312 for supporting the rotation of the clamping ring 33 is fixedly installed at the outer end of the shell tube 31. By symmetrically opening the limiting grooves 311 on the inner side surface of the shell tube 31, it is convenient for the conical head 131 to be quickly positioned and installed through the limiting blocks 132 during installation. At the same time, by setting the support spring 312, the driving of the clamping ring 33 to rotate is realized, facilitating the clamping ring 33 to stably lock the conical head 131.

[0044] Refer to Figure 6As shown in the figure, the feed head 5 includes a disk plate 51, a wheel frame group 52 and a main head shell 53. The wheel frame group 52 is evenly installed on the outer side surface of the disk plate 51. The main head shell 53 is fixedly installed at the center of the disk plate 51, and both the wheel frame group 52 and the main head shell 53 are fixedly connected to the disk plate 51. By setting the structure of the feed head 5, the wheel frame group 52 and the main head shell 53 are arranged on the disk plate 51, so that during use, the wheel frame group 52 can stably support on the inner side surface of the pipeline, and at the same time, through the main head shell 53, it can ensure better advancement in the pipeline.

[0045] Embodiment 2

[0046] Refer to Figure 1 、 Figure 4 and Figure 5 As shown in the figure, a bimetallic pipeline internal composite detection device includes a detection main shaft 1. A magnetic flux leakage probe 2 is sleeved in the middle of the detection main shaft 1. The magnetic flux leakage probe 2 is fixedly connected to the detection main shaft 1. One end of the detection main shaft 1 is installed with a connection shell 3. The connection shell 3 is snap-fitted and fixed to the detection main shaft 1. An ultrasonic detection component 4 is arranged at the outer end of the connection shell 3. The ultrasonic detection component 4 is fixedly connected to the connection shell 3.

[0047] Refer to Figure 4 and Figure 5 As shown in the figure, the ultrasonic detection component 4 includes a detection disk 41, an installation shell 42 and a detection head 43. The installation shells 42 are evenly arranged on the outer side surface of the detection disk 41, and the installation shells 42 are fixedly connected to the detection disk 41. By setting the structure of the ultrasonic detection component 4, it can ensure that several installation shells 42 can be arranged on the detection disk 41 during use, and then through the installation shells 42, the detection head 43 can be conveniently inserted and installed for use, so that the detection head 43 can stably detect the metal pipeline. The model of the detection head 43 is L042M4W.

[0048] Refer to Figure 4 and Figure 5 As shown in the figure, engaging grooves 411 for positioning and inserting the installation shells 42 are evenly opened on the outer side surface of the detection disk 41, and wire discharge grooves 412 communicating with the engaging grooves 411 are evenly opened on one end face of the detection disk 41 along the circumferential direction. By evenly opening the engaging grooves 411 on the outer side surface of the detection disk 41, during use, the installation shells 42 can be directly positioned and inserted into the engaging grooves 411, which is easy for quick installation and use. At the same time, through the setting of the wire discharge grooves 412, it can ensure stable wiring operation after the detection head 43 is installed.

[0049] Refer to Figure 4 and Figure 5As shown, the mounting shell 42 includes a top shell portion 421 and an inserting shell portion 422. The inserting shell portion 422 is provided on the lower end surface of the top shell portion 421, and the inserting shell portion 422 is integrally formed with the top shell portion 421. By setting the structure of the mounting shell 42, it is ensured that during use, the top shell portion 421 can be connected by inserting the inserting shell portion 422 into the engaging groove 411. Moreover, the lower end surface of the inserting shell portion 422 is an open structure, which facilitates the wiring operation of the detection head 43 better.

[0050] In this embodiment, during actual pipeline detection, the connection flange 12 on the shaft rod portion 11 is used to connect with an external driving device. During normal detection, the magnetic flux leakage probe 2 can be directly driven by the detection main shaft 1 for magnetic flux leakage detection. When encountering a more complex pipeline, the device can be assembled. The conical head 131 of the positioning seat 13 is inserted into the connection shell 3, and then the ultrasonic detection assembly 4 is fixedly connected to the detection main shaft 1. In this way, during the detection process, the magnetic flux leakage probe 2 and the ultrasonic detection head 43 can be used in cooperation for detection. Then, the assembled device is placed inside the pipeline for normal composite detection use.

[0051] The above is the preferred embodiment of the present utility model. Those skilled in the art to which the present utility model pertains can also make changes and modifications to the above embodiment. Therefore, the present utility model is not limited to the above specific embodiment. Any obvious improvement, replacement, or variation made by those skilled in the art based on the present utility model belongs to the protection scope of the present utility model.

Claims

1. A double-metal pipeline internal composite detection device, comprising a detection main shaft (1), characterized in that: A magnetic flux leakage probe (2) is sleeved in the middle of the detection spindle (1), and the magnetic flux leakage probe (2) is fixedly connected to the detection spindle (1). A connection shell (3) is installed at one end of the detection spindle (1), and the connection shell (3) is snap-fitted and fixed to the detection spindle (1). An ultrasonic detection component (4) is arranged at the outer end of the connection shell (3), and the ultrasonic detection component (4) is fixedly connected to the connection shell (3). A feed head (5) is also fixedly installed at the outer end of the ultrasonic detection component (4).

2. The composite detection device inside a bimetallic pipeline according to claim 1, characterized in that: The detection spindle (1) includes a shaft rod portion (11), a connection flange (12) and a positioning seat (13). The connection flange (12) and the positioning seat (13) are respectively arranged at both ends of the shaft rod portion (11), and both the connection flange (12) and the positioning seat (13) are fixedly connected to the shaft rod portion (11).

3. The composite detection device inside a bimetallic pipeline according to claim 2, characterized in that: The positioning seat (13) includes a conical head (131) and a limiting block (132). The limiting blocks (132) are symmetrically arranged on the outer side surface of the conical head (131), and the limiting blocks (132) are integrally formed with the conical head (131).

4. A bimetallic pipe internal composite detection device according to claim 3, characterized in that: The connection shell (3) includes a shell tube (31), an outer expansion frame (32) and a clamping ring (33). The outer expansion frames (32) are symmetrically arranged on the outer side surface of the shell tube (31), and the outer expansion frames (32) are integrally formed with the shell tube (31). The clamping ring (33) is rotatably installed on the outer expansion frame (32).

5. The composite detection device inside a bimetallic pipe according to claim 4, characterized in that: Limiting grooves (311) for installing the limiting blocks (132) are symmetrically formed on the inner side surface of the shell tube (31), and a support spring (312) for supporting the rotation of the clamping ring (33) is also fixedly installed at the outer end of the shell tube (31).

6. The bimetallic pipeline internal composite detection device according to claim 5, characterized in that: The ultrasonic detection component (4) includes a detection disc (41), an installation shell (42) and a detection head (43). The installation shells (42) are uniformly arranged on the outer side surface of the detection disc (41), and the installation shells (42) are fixedly connected to the detection disc (41).

7. The composite detection device inside a bimetallic pipeline according to claim 6, characterized in that: Clamping grooves (411) for positioning and inserting the installation shells (42) are uniformly formed on the outer side surface of the detection disc (41), and wire discharge grooves (412) communicating with the clamping grooves (411) are uniformly formed on one end face of the detection disc (41) along the circumferential direction.

8. A bimetallic pipe internal composite detection device according to claim 7, characterized in that: The installation shell (42) includes a top shell portion (421) and an insertion shell portion (422). The insertion shell portion (422) is arranged at the lower end face of the top shell portion (421), and the insertion shell portion (422) is integrally formed with the top shell portion (421).

9. The composite detection device inside a bimetallic pipeline according to claim 8, characterized in that: The feed head (5) includes a disc plate (51), a wheel frame group (52) and a main head shell (53). The wheel frame groups (52) are uniformly installed on the outer side surface of the disc plate (51). The main head shell (53) is fixedly installed at the center of the disc plate (51), and both the wheel frame group (52) and the main head shell (53) are fixedly connected to the disc plate (51).

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