An integrated heat sink structure for a giant magnetostrictive transducer

Abstract

The application relates to an integrated heat dissipation structure for a giant magnetostrictive transducer, which internally cools the transducer from two aspects. One aspect is to reduce heat generation. In order to inhibit eddy current loss of a permanent magnet ring, the complete permanent magnet ring is first divided into a tile-shaped permanent magnet ring, and the tile-shaped permanent magnet ring is coated with insulating paint. Secondly, in order to inhibit eddy current loss of a 3D-printed copper alloy framework, a longitudinal and transverse intersecting cross-shaped fine gap is designed in the internal structure of the two end disc structures and the middle circular tube structure of the integrated framework, and the surfaces of the left and right frameworks are coated with insulating paint. The other aspect is to increase heat conduction. The permanent magnet ring placement structure and the coil winding structure are integrated into a framework. In order to facilitate the installation of the tile-shaped permanent magnet ring, the framework is divided into two parts which can be separated left and right. After the tile-shaped permanent magnet ring is installed, the left and right frameworks are assembled into an integral framework through the mortise and tenon structures at the upper and lower ends. Secondly, the air gap generated during assembly is coated with heat-conducting silicone grease.

Description

Technical Field

[0001] This invention relates to an integrated heat dissipation structure for a giant magnetostrictive transducer, belonging to the technical field of giant magnetostrictive transducers. Background Technology

[0002] When a giant magnetostrictive transducer performs the energy conversion process from electrical energy to magnetic energy to mechanical energy, energy loss is inevitable. This energy loss occurs through various means, including eddy current loss, resistive loss, and hysteresis loss. The lost energy cannot be output externally but dissipates as heat, which not only reduces the overall energy conversion efficiency of the device but also causes a rapid increase in the temperature of the internal components.

[0003] The magnetostrictive material in the transducer exhibits a temperature effect; its magnetostriction coefficient changes significantly with temperature at both low and high temperatures. Only within the temperature range of 0–80°C does the magnetostriction coefficient remain relatively stable. Furthermore, the magnetic properties of permanent magnet materials also decrease in high-temperature environments. Therefore, to achieve optimal performance of the magnetostrictive transducer, it is necessary to suppress eddy current losses and other degradation within the transducer, and to optimize heat dissipation to control the internal temperature within a reasonable range. This improves energy conversion efficiency and stabilizes the magnetostriction coefficient of the magnetostrictive material, enabling the transducer to operate efficiently and stably.

[0004] Due to limited internal space in the transducer, an additional independent cooling system cannot be added. Therefore, heat dissipation optimization is necessary to enhance the transducer's internal heat conduction capacity and prevent performance degradation of the core drive unit due to overheating. The main reasons for overheating of the core drive unit include the low thermal conductivity of traditional frames and air gaps between components. The rise of 3D-printed copper alloy technology offers a new approach to solving the problems of low thermal conductivity of the transducer's internal frame and low integration of various parts. Summary of the Invention

[0005] This invention addresses the following technical problems: It solves the problem of high heat generation in permanent magnet rings by providing tile-shaped permanent magnet rings that are cut and coated with insulating varnish, indirectly improving heat dissipation of the core drive unit; it reduces the heat generated by eddy current losses in the 3D-printed copper alloy skeleton after coating with insulating varnish by designing crisscrossing "+" shaped slits inside the two end disc structures and the middle circular tube structure of the integrated skeleton, thereby reducing heat generation by suppressing eddy current losses; it solves the problem of low integration in traditional heat dissipation structures and gaps between the permanent magnet ring placement structure and the coil winding structure that are detrimental to heat conduction by providing an integrated skeleton that integrates the permanent magnet ring placement structure and the coil winding structure; and it overcomes the problem of gaps during assembly hindering heat conduction by applying thermally conductive silicone grease to reduce gaps where air gaps may occur during assembly, for example, filling the gap between the drive coil and the outer shell with thermally conductive silicone grease during assembly to achieve efficient heat transfer.

[0006] The technical solution of this invention is an integrated heat dissipation structure for a giant magnetostrictive transducer, comprising: a top end cover, an outer shell, a bottom end cover, a drive coil, an integrated frame, a tile-shaped permanent magnet ring, and a core drive unit; the tile-shaped permanent magnet ring is attached to a tile-shaped permanent magnet ring fitting groove on the inner wall of the integrated frame, and the left and right frames are assembled from top to bottom in a staggered manner through their respective mortise and tenon joints after the tile-shaped permanent magnet ring is attached, and the assembled frame is a whole.

[0007] The integrated skeleton is divided into a left skeleton and a right skeleton. The structure on the left skeleton includes the first mortise and tenon joint, the second mortise and tenon joint, the third mortise and tenon joint, the fourth mortise and tenon joint, the tile-shaped permanent magnet ring fitting groove, the cross-shaped slits inside the disc structures at both ends of the left skeleton, and the cross-shaped slits inside the circular tube structure in the middle of the left skeleton.

[0008] Preferably, the size range of the cross-shaped slits inside the disc structures at both ends of the left skeleton and the cross-shaped slits inside the central tube structure of the left skeleton needs to be determined based on the overall size of the left skeleton and the printing precision of the 3D printed copper alloy technology; optionally, the cross-shaped slits inside the disc structures at both ends of the left skeleton and the cross-shaped slits inside the central tube structure of the left skeleton are both 1-2 mm; preferably, a slit width of 1-2 mm is sufficient to reduce eddy current loss.

[0009] The integrated skeleton is divided into a left skeleton and a right skeleton. The structure on the right skeleton includes the first mortise and tenon joint, the second mortise and tenon joint, the third mortise and tenon joint, the fourth mortise and tenon joint, the tile-shaped permanent magnet ring fitting groove, the cross-shaped slits inside the disc structures at both ends of the right skeleton, and the cross-shaped slits inside the circular tube structure in the middle of the right skeleton.

[0010] Preferably, the dimensions of the cross-shaped slits inside the disc structures at both ends of the right skeleton and the cross-shaped slits inside the central tube structure of the right skeleton need to be determined based on the overall dimensions of the right skeleton and the printing precision of the 3D printed copper alloy technology. Optionally, the cross-shaped slits inside the disc structures at both ends of the right skeleton and the cross-shaped slits inside the central tube structure of the right skeleton are both 1-2 mm; preferably, a slit width of 1-2 mm is sufficient to reduce eddy current losses.

[0011] The mortise and tenon joints are assembled in a staggered manner from top to bottom to fit together. There are a total of four mortise and tenon joints, with the four mortise and tenon structures on the left and right frames corresponding to each other.

[0012] The left and right skeletons were manufactured using 3D printing copper alloy technology.

[0013] The tile-shaped permanent magnet rings that are attached to the inner wall of the integrated frame need to be cut from permanent magnet rings, and the tile-shaped permanent magnet rings obtained after cutting also need to be coated with insulating varnish.

[0014] After the left and right frames are assembled, an integrated frame is formed. A top end cap and a bottom end cap for the magnetic circuit are placed on the top and bottom of the integrated frame, respectively. In addition to serving as a magnetic circuit, the top and bottom end caps also ensure that the disk surface at the top of the integrated frame is level with the disk surface at the bottom of the integrated frame. A circular hole is left between the top and bottom end caps to ensure that the core drive unit can pass through.

[0015] The outer surface of the circular tube structure in the middle section of the integrated skeleton can be wound with flat copper wire or Litz wire to form the drive coil of the super magnetostrictive transducer.

[0016] After the drive coil is coated with thermal grease, it is covered with an outer shell, so that all the aforementioned structures are enclosed inside, making it easier to assemble it as a whole into the device later.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] (1) This invention overcomes the problem of high heat generation power of permanent magnet rings by providing tile-shaped permanent magnet rings that are cut and coated with insulating varnish, thereby indirectly improving the heat dissipation of the core drive unit. Individual permanent magnet rings have high eddy current losses and high heat generation power density, directly affecting the heat dissipation of the core drive unit. Simply dividing and assembling permanent magnet rings only facilitates installation and cannot reduce eddy currents. This invention coats the surface of the divided tile-shaped permanent magnet rings with insulating varnish, confining eddy currents to narrow loops. The net induced potential of the loop is small, and the loop is long, effectively suppressing eddy currents and thus indirectly improving the heat dissipation of the core drive unit.

[0019] (2) This invention reduces the heat generated by eddy current loss in the 3D printed copper alloy skeleton after coating with insulating varnish. The invention designs crisscrossing "+" shaped slits inside the two end disc structures and the middle circular tube structure of the integrated skeleton to reduce heat generation by suppressing eddy current loss.

[0020] (3) In view of the low integration of traditional heat dissipation structures, this invention solves the problem of gaps between the permanent magnet ring placement structure and the coil winding structure that are not conducive to heat conduction. It provides an overall skeleton that integrates the permanent magnet ring placement structure and the coil winding structure by using 3D printing copper alloy technology.

[0021] (4) The present invention overcomes the problem that gaps during assembly are not conducive to heat conduction. In places where air gaps will be generated during assembly, thermal grease is applied to reduce the gaps. For example, during assembly, thermal grease is filled between the drive coil and the outer shell to achieve efficient heat transfer.

[0022] (5) The integrated frame of the present invention adopts a mortise and tenon structure for connection. The mortise and tenon joints are assembled from top to bottom in a staggered manner to fit together, so that the left and right frames are connected into a whole frame through four mortise and tenon joints. This connection method saves the internal size of the transducer and is relatively reliable. Attached Figure Description

[0023] Figure 1A This is the overall assembly drawing of the transducer;

[0024] Figure 1B This is a cross-sectional view of the overall internal structure of the transducer.

[0025] Figure 2A This is a structural diagram of the left skeleton;

[0026] Figure 2B This is a schematic diagram of the internal cuts in the left skeleton;

[0027] Figure 3A This is a structural diagram of the right skeleton;

[0028] Figure 3B This is a schematic diagram of the internal cuts in the right skeleton;

[0029] Figure 4A This is a schematic diagram of the assembly of the integrated skeleton;

[0030] Figure 4B This is a schematic diagram of the structure after the integrated skeleton is assembled.

[0031] Figure 5 This is a schematic diagram of the structure of a tile-shaped permanent magnet ring.

[0032] In the diagram, 1-top end cap, 2-outer shell, 3-bottom end cap, 4-drive coil, 5-integrated frame, 5-1-left frame, 5-2-right frame, 5-1-f-the cross-shaped slit inside the disc structure at both ends of the left frame, 5-1-g-the cross-shaped slit inside the central tube structure of the left frame, 5-2-f-the cross-shaped slit inside the disc structure at both ends of the right frame, 5-2-g-the cross-shaped slit inside the central tube structure of the right frame, 5-1-a-the first mortise and tenon joint of the left frame, 5-1- b-Second mortise and tenon joint of the left frame, 5-1-c-Third mortise and tenon joint of the left frame, 5-1-d-Fourth mortise and tenon joint of the left frame, 5-1-e-Tile-shaped permanent magnet ring fitting groove of the left frame, 5-2-a-First mortise and tenon joint of the right frame, 5-2-b-Second mortise and tenon joint of the right frame, 5-2-c-Third mortise and tenon joint of the right frame, 5-2-d-Fourth mortise and tenon joint of the right frame, 5-2-e-Tile-shaped permanent magnet ring fitting groove of the right frame, 6-Tile-shaped permanent magnet ring, 7-Core drive unit. Detailed Implementation

[0033] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0034] like Figure 1A As shown, the giant magnetostrictive transducer of this invention consists of a top end cap 1, an outer shell 2, a bottom end cap 3, a drive coil 4, an integrated frame 5, tile-shaped permanent magnet rings 6, and a core drive unit 7. The top end cap 1, which mates with the magnetic circuit, is placed on the top of the integrated frame 5, and the bottom end cap 3, which also mates with the magnetic circuit, is placed on the bottom of the integrated frame 5. The end caps at both ends, in addition to mate with the magnetic circuit, also ensure that the disk surfaces at the top and bottom of the integrated frame 5 remain horizontal. A circular hole is provided between the top end cap 1 and the bottom end cap 3 to allow the core drive unit 7 to pass through. During assembly, the tile-shaped permanent magnet rings 6 are first assembled into their respective tile-shaped permanent magnet ring fitting grooves from the sides of the left frame 5-1 and the right frame 5-2, and then the core drive unit 7 is assembled in the middle of the integrated frame 5. Flat copper wire or Litz wire can be wound around the outer surface of the circular tube structure in the middle section of the integrated frame 5 to form the drive coil 4 of the giant magnetostrictive transducer. After applying thermally conductive silicone grease to the outer surface of the drive coil 4 and the inner surface of the outer shell 2, a cylindrical outer shell 2 is placed around the drive coil 4, enclosing all the aforementioned structures to facilitate subsequent assembly into the device as a whole. The integrated frame 5 is divided into a left frame 5-1 and a right frame 5-2.

[0035] like Figure 1BAs shown, the magnetostrictive transducer of this invention consists of a top end cap 1, an outer shell 2, a bottom end cap 3, a drive coil 4, an integrated frame 5, a tile-shaped permanent magnet ring 6, and a core drive unit 7. The cross-sectional view also shows the cross-shaped slits 5-1-f inside the disc structures at both ends of the left frame, the cross-shaped slits 5-1-g inside the central cylindrical structure of the left frame, the cross-shaped slits 5-2-f inside the disc structures at both ends of the right frame, and the cross-shaped slits 5-2-g inside the central cylindrical structure of the right frame. Even after the integrated frame 5 is coated with insulating varnish, eddy currents are still generated within the frame. These cross-shaped slits within the frame confine the eddy currents to a small area through a combination of longitudinal and transverse slits, thereby reducing eddy current losses and achieving the goal of reducing heat generation in the 3D-printed copper alloy frame.

[0036] like Figure 2A As shown, the features on the outer surface of the left frame 5-1 include the first mortise and tenon joint 5-1-a, the second mortise and tenon joint 5-1-b, the third mortise and tenon joint 5-1-c, the fourth mortise and tenon joint 5-1-d, and the tile-shaped permanent magnet ring fitting groove 5-1-e. The tile-shaped permanent magnet ring fitting groove 5-1-e is evenly arranged axially on the inner wall of the frame and is symmetrical to the tile-shaped permanent magnet ring fitting groove 5-2-e of the right frame. The four mortise and tenon structures of the left frame 5-1 also correspond exactly to the four mortise and tenon structures of the right frame 5-2.

[0037] like Figure 2B As shown, the cross-shaped slits 5-1-f and 5-1-g inside the circular disc structures at both ends of the left skeleton are represented by dashed lines. The cross-shaped slits 5-1-f inside the circular disc structures at both ends of the left skeleton consist of longitudinal slits parallel to the radial direction and transverse slits parallel to the arc direction. Similarly, the cross-shaped slits 5-1-g inside the circular tube structure in the middle of the left skeleton also consist of axial longitudinal slits and transverse slits parallel to the arc direction. The dimensional range of the cross-shaped slits 5-1-f and 5-1-g inside the circular disc structures at both ends of the left skeleton and the middle circular tube structure of the left skeleton needs to be determined based on the overall dimensions of the left skeleton 5-1 and the printing precision of the 3D printed copper alloy technology. Generally, a slit width of 1–2 mm is sufficient to reduce eddy current losses.

[0038] like Figure 3AAs shown, the features on the outer surface of the right frame 5-2 include the first mortise and tenon joint 5-2-a, the second mortise and tenon joint 5-2-b, the third mortise and tenon joint 5-2-c, the fourth mortise and tenon joint 5-2-d, and the tile-shaped permanent magnet ring fitting groove 5-2-e. The tile-shaped permanent magnet ring fitting groove 5-2-e is evenly arranged axially on the inner wall of the frame and is symmetrical to the tile-shaped permanent magnet ring fitting groove 5-1-e of the left frame. The four mortise and tenon structures of the right frame 5-2 also correspond exactly to the four mortise and tenon structures of the left frame 5-1.

[0039] like Figure 3B As shown, the cross-shaped slits 5-2-f and 5-2-g inside the circular structures at both ends of the right skeleton are represented by dashed lines. The cross-shaped slits 5-2-f inside the circular structures at both ends of the right skeleton consist of longitudinal slits parallel to the radial direction and transverse slits parallel to the arc direction. Similarly, the cross-shaped slits 5-2-g inside the circular structure in the middle of the right skeleton also consist of axial longitudinal slits and transverse slits parallel to the arc direction. The dimensional range of the cross-shaped slits 5-2-f and 5-2-g inside the circular structures at both ends of the right skeleton needs to be determined based on the overall dimensions of the right skeleton 5-2 and the printing precision of the 3D printed copper alloy technology. Generally, a slit width of 1–2 mm is sufficient to reduce eddy current losses.

[0040] like Figure 4A As shown, the integrated frame 5 is composed of a left frame 5-1 and a right frame 5-2, which are assembled from top to bottom in a staggered manner to fit together. Both the left frame 5-1 and the right frame 5-2 have four corresponding mortise and tenon joints. The integrated frame 5 integrates the permanent magnet ring placement structure and the coil winding structure. This not only reduces the air gap, thus improving heat dissipation, when the integration is not high, but also saves the internal size of the transducer, and the mortise and tenon joint structure is relatively robust.

[0041] like Figure 4B As shown, the integrated skeleton 5, assembled from the left skeleton 5-1 and the right skeleton 5-2, is a single integral skeleton. The two ends of the integrated skeleton 5 are disc-shaped structures with a certain thickness, while the middle is a smooth, tubular structure. Both the left skeleton 5-1 and the right skeleton 5-2 are manufactured using 3D printing copper alloy technology.

[0042] like Figure 5As shown, the tile-shaped permanent magnet ring 6 is obtained by cutting a complete permanent magnet ring. The resulting tile-shaped permanent magnet ring 6 also needs to be coated with insulating varnish to reduce eddy current losses, thereby improving the heat dissipation of the core drive unit 7. After being coated with insulating varnish, the tile-shaped permanent magnet ring 6 can be assembled from the sides of the left frame 5-1 and the right frame 5-2 into the tile-shaped permanent magnet ring fitting groove 5-1-e of the left frame and the right frame, respectively.

[0043] This invention integrates a permanent magnet ring, a permanent magnet ring placement structure, and a coil winding structure, achieving internal cooling of the transducer in two ways: reducing heat generation and increasing heat transfer. Two measures are taken to reduce heat generation: first, to suppress eddy current losses in the permanent magnet ring, the complete permanent magnet ring is divided into tile-shaped permanent magnet rings, which are then coated with insulating varnish; second, to suppress eddy current losses in the 3D-printed copper alloy skeleton, crisscrossing "+" shaped slits are designed inside the disc structures at both ends of the left and right skeletons and inside the central cylindrical structure, and insulating varnish is applied to the surfaces of the left and right skeletons. Two measures are also taken to increase heat transfer. First, the permanent magnet ring placement structure and the coil winding structure are integrated into a frame. The tile-shaped permanent magnet rings coated with insulating varnish can be assembled into the corresponding tile-shaped permanent magnet ring fitting grooves from the sides of the left and right frames, respectively. After the tile-shaped permanent magnet rings are installed, the two frames are assembled into a whole frame through the mortise and tenon structure at the upper and lower ends. Both the left and right frames are manufactured using 3D printing copper alloy technology. This integrated frame is equivalent to replacing the air gap with a high thermal conductivity copper alloy, which greatly improves the heat transfer efficiency. Second, thermal grease is applied to places where air gaps will occur during assembly to increase heat transfer. For example, thermal grease is filled between the drive coil and the outer shell during assembly to achieve efficient heat transfer.

[0044] The above description, in conjunction with specific embodiments, provides a further detailed explanation of the present invention, but it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications or substitutions should be considered to fall within the scope of protection defined by the claims submitted herein.

Claims

1. An integrated heat dissipation structure for a giant magnetostrictive transducer, characterized in that: The system includes a top end cap (1), an outer shell (2), a bottom end cap (3), a drive coil (4), an integrated frame (5), a tile-shaped permanent magnet ring (6), and a core drive unit (7). The integrated frame (5) is divided into a left frame (5-1) and a right frame (5-2). After the left frame (5-1) and the right frame (5-2) are assembled, they form the integrated frame (5). A top end cap (1) for the magnetic circuit is placed on the top of the integrated frame (5), and a bottom end cap (3) for the magnetic circuit is placed on the bottom of the integrated frame (5). A circular hole is left between the top end cap (1) and the bottom end cap (3) to ensure that the core drive unit (7) can pass through. The outer surface of the middle section of the circular tube structure can be wound with flat copper wire or Litz wire to form the drive coil (4) of the super magnetostrictive transducer; the outer shell (2) is put on the periphery of the drive coil (4) after being coated with thermally conductive silicone grease; the tile-shaped permanent magnet ring (6) is attached to the tile-shaped permanent magnet ring fitting groove on the inner wall of the integrated skeleton (5), and the left skeleton (5-1) and the right skeleton (5-2) are assembled from top to bottom through their respective mortise and tenon joints after the tile-shaped permanent magnet ring (6) is attached, and after assembly, it becomes an integral skeleton; the tile-shaped permanent magnet ring (6) attached to the inner wall of the integrated skeleton (5) is obtained by cutting the permanent magnet ring, and the surface of the tile-shaped permanent magnet ring (6) obtained after cutting is coated with insulating paint.

2. The integrated heat dissipation structure of the giant magnetostrictive transducer according to claim 1, characterized in that, The structures on the left frame (5-1) include the first mortise and tenon joint (5-1-a), the second mortise and tenon joint (5-1-b), the third mortise and tenon joint (5-1-c), the fourth mortise and tenon joint (5-1-d), the tile-shaped permanent magnet ring fitting groove (5-1-e), the cross-shaped slits inside the disc structures at both ends of the left frame (5-1-f), and the cross-shaped slits inside the circular tube structure in the middle of the left frame (5-1-g).

3. The integrated heat dissipation structure of the giant magnetostrictive transducer according to claim 1, characterized in that, The integrated frame (5) is divided into a left frame (5-1) and a right frame (5-2). The structure on the right frame (5-2) includes the first mortise and tenon joint (5-2-a), the second mortise and tenon joint (5-2-b), the third mortise and tenon joint (5-2-c), the fourth mortise and tenon joint (5-2-d), the tile-shaped permanent magnet ring fitting groove (5-2-e), the cross-shaped slits inside the disc structures at both ends of the right frame (5-2-f), and the cross-shaped slits inside the round tube structure in the middle of the right frame (5-2-g).

4. The integrated heat dissipation structure of the giant magnetostrictive transducer according to claim 1, characterized in that: The mortise and tenon joints are assembled in a staggered manner from top to bottom to fit together. There are a total of four mortise and tenon joints, with the four mortise and tenon structures on the left frame (5-1) and the right frame (5-2) corresponding to each other.

5. The integrated heat dissipation structure of the giant magnetostrictive transducer according to claim 1, characterized in that: The left skeleton (5-1) and right skeleton (5-2) are manufactured using 3D printing copper alloy technology.

6. The integrated heat dissipation structure of the giant magnetostrictive transducer according to claim 1, characterized in that: The top end cap (1) and the bottom end cap (3) cooperate with the magnetic circuit and ensure that the disk surface at the top of the integrated skeleton (5) and the disk surface at the bottom of the integrated skeleton (5) remain horizontal.

7. The integrated heat dissipation structure of the giant magnetostrictive transducer according to claim 1, characterized in that: The core drive unit (7) is assembled in the middle of the integrated frame (5).

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