Electric signal transmission structure of rotating main shaft of high-temperature vacuum furnace

Abstract

The invention discloses an electric signal transmission structure of a rotating main shaft of a high-temperature vacuum furnace, and relates to the technical field of solution state detection signal transmission in the high-temperature vacuum furnace, the electric signal transmission structure comprises a frame structure, a reaction chamber and a main shaft assembly, one side of the frame structure is provided with a mounting base body, and the mounting base body comprises two mounting plates; wherein a spindle motor is fixed on one mounting plate, a spindle assembly is rotatably mounted on the other mounting plate through magnetic fluid, one end of the spindle assembly is connected with the spindle motor, and the other end of the spindle assembly is positioned in the reaction chamber; a slide wire ring is further installed outside the main shaft assembly and located between the two installation plates of the installation base body. The technical problem that a slide wire ring is prone to polluting a high-temperature furnace chamber in the existing silicon carbide crystal preparation process is solved, and the reliability of signal conversion is improved.

Description

Technical Field

[0001] The invention relates to the technical field of solution state detection signal transmission in a high-temperature vacuum furnace, and in particular to an electrical signal transmission structure of a rotating spindle of a high-temperature vacuum furnace. Background Art

[0002] With the rise of the silicon carbide production industry and the advancement of science and technology, the growth and preparation methods of silicon carbide have become diversified, and a large number of crystal furnaces with various preparation methods have emerged. However, no matter what preparation method is used, it is necessary to conduct diversified monitoring and detection of the material state in the high-temperature vacuum furnace during the process production.

[0003] Since the materials for preparing silicon carbide crystals must be placed in a high-temperature and high-cleanliness furnace chamber environment, the real-time status detection of the prepared materials in the furnace must ensure that the vacuum and pure environment of the chamber is not polluted, and that the detection devices and accessories are not harmed by high temperatures. More importantly, it is also necessary to ensure that the device is stable and reliable, and that the detected physical quantities can be effectively transmitted from the inside of the chamber to the external environment to be analyzed and processed by the control center. The existing technology has realized the detection of the actual height of the molten liquid level of the material in the vacuum high-temperature furnace, but the method for transmitting the physical path of the signal from the rotating state to the outside of the furnace is: installing a sliding wire ring in the shaft synchronized with the rotating signal in the furnace, so that the detected signal is converted from a rotating state to a stationary state.

[0004] Since the wire slide ring is installed in a high-purity, high-temperature furnace chamber, in actual applications, the wire slide ring body often fails to work normally and stably in a high-temperature environment due to the nature of the manufacturing material, which often causes many adverse crystallization problems such as contamination of the high-purity furnace chamber and distortion of the transmitted signal. Summary of the invention

[0005] The embodiment of the present application solves the technical problem that the sliding wire ring is prone to contaminating the high-temperature furnace chamber during the current silicon carbide crystal preparation process by providing an electrical signal transmission structure for the rotating spindle of a high-temperature vacuum furnace, thereby improving the reliability of signal conversion.

[0006] In order to solve the above technical problems, the present invention adopts the following technical scheme: an electrical signal transmission structure for a rotating spindle of a high-temperature vacuum furnace, comprising a frame structure, a reaction chamber and a spindle assembly, a mounting base is provided on one side of the frame structure, the mounting base comprises two mounting plates, a spindle motor is fixed on one mounting plate, and the spindle assembly is rotatably mounted on the other mounting plate through a magnetic fluid, one end of the spindle assembly is connected to the spindle motor, and the other end of the spindle assembly is located in the reaction chamber; a sliding wire ring is also installed on the outside of the spindle assembly, and the sliding wire ring is located between the two mounting plates of the mounting base.

[0007] Since the wire loop is located between the two mounting plates of the mounting base, rather than inside the reaction chamber, the influence of the high temperature environment on the wire loop material is avoided, thereby avoiding the problem of high-purity environment in the furnace chamber being polluted by the high-temperature decomposition of the wire loop material. At the same time, the wire loop works at room temperature, effectively reducing the failure rate and improving the stability and reliability of signal conversion.

[0008] Furthermore, the magnetic fluid comprises a magnetic fluid outer ring and a magnetic fluid inner ring, wherein an insulating isolation ring is provided between the magnetic fluid outer ring and a mounting plate of the mounting base, and the magnetic fluid inner ring is interference fit with the main shaft assembly.

[0009] Furthermore, a bellows is provided between the reaction chamber and the magnetic fluid, the bellows is nested in the outer periphery of the spindle assembly, one end of the bellows is sealed and connected to the center of the top of the reaction chamber through an insulating spacer, and the other end of the bellows is sealed and connected to the magnetic fluid.

[0010] Furthermore, the spindle assembly includes a spindle front section and a spindle rear section, wherein the spindle rear section is connected to the motor, the spindle front section is rotatably mounted on a mounting plate of the mounting base and is connected to the spindle rear section through a coupling, and the sliding wire ring is installed on the outside of the spindle front section.

[0011] Furthermore, the coupling includes a main coupling body, a slave coupling body and an elastic connecting piece, wherein the main coupling body is fixed to the rear section of the main shaft, the slave coupling body is fixed to the front section of the main shaft, and the elastic connecting piece is an insulator; the coupling connects the rear section of the main shaft with the front section of the main shaft to ensure the overall rotational movement of the main shaft, and the elastic connecting piece is an insulator to avoid current transmission between the front and rear sections of the main shaft, ensuring that the front section of the main shaft can maintain an insulating state in the high temperature environment in the furnace cavity, thereby preventing signal interference and furnace cavity pollution.

[0012] Furthermore, the sliding wire ring includes an outer ring body and an inner ring body that can rotate relative to the outer ring body. The inner ring body is nested outside the front section of the rotating shaft and forms the same rotating body. A U-fork block is provided on the edge of the outer ring body. A rotation-blocking rod is engaged in the U-fork block, and the end of the rotation-blocking rod is fixed to the mounting base. Thus, the inner ring body rotates synchronously with the front section of the main shaft, and can transmit the physical signal collected by the front section of the main shaft to the outer ring body. The outer ring body is fixed by the rotation-blocking rod, and can convert the rotating signal into a relatively static signal, which is convenient for subsequent data processing and transmission.

[0013] Furthermore, the inner ring body of the sliding wire ring is connected to the main shaft assembly through an input line, and the outer ring body of the sliding wire ring is connected to an external electrical cabinet through an output line.

[0014] Furthermore, both the rear section and the front section of the spindle have hollow passages, the hollow passage of the front section of the spindle is connected to the reaction chamber, and a quartz lens for infrared light to pass through is sealed and installed at one end of the front section of the spindle away from the reaction chamber; thus, when infrared light passes through the quartz lens, the spindle temperature can be monitored, and overheating problems can be discovered and dealt with in a timely manner.

[0015] Furthermore, one side of the quartz lens cooperates with the end of the front section of the main shaft through a sealing ring, and the other side of the quartz lens is pressed toward the sealing ring through a sealing flange; thereby, a good seal can be formed between the quartz lens and the high-temperature furnace chamber, and the quartz lens can be easily disassembled to clean the dirt on its surface.

[0016] Furthermore, the front section of the spindle is also provided with an annular cavity, and the cavity is connected with a guide pipe for cooling water to flow; thereby, the front section of the spindle can be cooled to prevent its own overheating from damaging its unique performance.

[0017] It can be seen from the above technical solutions that the present invention has at least the following technical effects or advantages: In the present invention, the wire loop is located between the two mounting plates of the mounting base, rather than inside the reaction chamber, thus avoiding the influence of the high temperature environment on the wire loop material, thereby avoiding the problem of high-purity environment in the furnace chamber being polluted by high-temperature decomposition of the wire loop material. At the same time, the wire loop works at room temperature, effectively reducing the failure rate and improving the stability and reliability of signal conversion. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for the description. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work: Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 A schematic diagram of the structure of the main shaft assembly and the mounting base; Figure 3 for Figure 2 A cross-sectional view of Figure 4 for Figure 3 A local enlarged schematic diagram of the middle A; Figure 5 for Figure 3 A partial enlarged schematic diagram of point B in the middle; Figure 6 for Figure 3 A partial enlarged schematic diagram of point C in the middle; Figure 7 This is a structural diagram of the sliding wire ring.

[0019] Explanation of the accompanying reference numerals: 1. frame structure, 2. reaction chamber, 3. spindle assembly, 4. spindle motor, 5. magnetic fluid, 6. sliding wire ring, 7. spindle front section, 8. spindle rear section, 9. coupling, 10. main coupling body, 11. slave coupling body, 12. elastic connecting part, 13. quartz lens, 14. pyrometer, 15. sealing ring, 16. sealing flange, 17. flow guide tube, 18. magnetic fluid outer ring, 19. magnetic fluid inner ring, 20. insulating isolation ring, 21. bellows, 22. insulating isolation plate, 23. outer ring body, 24. inner ring body, 25. anti-rotation rod, 26. mounting base. DETAILED DESCRIPTION In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be described clearly and completely in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments in this patent, other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this patent.

[0020] The present invention discloses an electrical signal transmission structure for a rotating spindle of a high-temperature vacuum furnace, which comprises a frame structure 1, a reaction chamber 2 and a spindle assembly 3. Figure 1 , Figure 2 As shown, a mounting base 26 is provided on one side of the frame structure 1, and the mounting base 26 includes two mounting plates at different heights, wherein a spindle motor 4 is mounted on the upper mounting plate, and a spindle assembly 3 is mounted on the lower mounting plate through a magnetic fluid 5, one end of the spindle assembly 3 is connected to the spindle motor 4 fixed on the upper mounting plate, and the other end of the spindle assembly 3 is located in the reaction chamber 2. The reaction chamber 2 is located below the mounting base 26, and the spindle assembly 3 extends into the reaction chamber 2 through the top of the reaction chamber 2. A sliding wire ring 6 is also installed on the outside of the spindle assembly 3, and the sliding wire ring 6 is located between the two mounting plates of the mounting base 26. Therefore, by placing the sliding wire ring 6 outside the reaction chamber 2, the problem of internal contamination of the furnace chamber caused by high temperature can be avoided, and the reliability of signal conversion is improved.

[0021] In this embodiment, if Figure 2 , Figure 3 As shown, the spindle assembly 3 includes a spindle front section 7 and a spindle rear section 8, wherein the upper portion of the spindle front section 7 is connected to a motor fixed to a mounting base 26 via a belt, and the upper end of the spindle rear section 8 is connected to the lower end of the spindle front section 7 via a coupling 9, so that when the motor rotates, the spindle front section 7 can rotate accordingly. In other embodiments, the spindle assembly 3 may also be an integrated structure.

[0022] like Figure 4As shown, the coupling 9 in this embodiment includes a main coupling body 10, a slave coupling body 11 and an elastic connector 12, wherein the elastic connector 12 is located between the main coupling body 10 and the slave coupling body 11, and is made of an insulating material, thereby being able to form an insulating isolation between the main shaft front section 7 and the main shaft rear section 8. In addition, the main shaft rear section 8 and the main shaft front section 7 both have a hollow passage, wherein the hollow passage of the main shaft front section 7 is communicated with the reaction chamber 2, and a quartz lens 13 for infrared rays to pass through is sealed and installed at one end of the main shaft front section 7 away from the reaction chamber 2, and correspondingly, a pyrometer 14 is provided at the top of the main shaft rear section 8. Specifically, in the present embodiment, the quartz lens 13 is sealingly mounted on the top of the spindle front section 7, wherein the cross section of the top of the spindle front section 7 is provided with an annular groove, a sealing ring 15 is provided in the annular groove, one side of the quartz lens 13 is in contact with the sealing ring 15, and the other side of the quartz lens 13 is pressed toward the sealing ring 15 through a sealing flange 16, thereby forming a good seal between the quartz lens 13 and the high-temperature furnace chamber, and at the same time, the quartz lens 13 is easy to disassemble to clean the dirt on its surface.

[0023] In addition, the spindle front section 7 is also provided with an annular cavity, which is formed between the hollow passage of the spindle front section 7 and its outer wall, and is connected to a guide tube 17 for circulating cooling water, thereby cooling the spindle front section 7 to prevent damage to its unique performance due to its own overheating.

[0024] like Figure 5 As shown, the magnetic fluid 5 includes a magnetic fluid outer ring 18 and a magnetic fluid inner ring 19, wherein the magnetic fluid outer ring 18 is relatively fixed to the mounting base 26, and the magnetic fluid inner ring 19 is relatively fixed to the spindle assembly 3. Specifically, the magnetic fluid outer ring 18 is mounted on the mounting plate of the mounting base 26 through an insulating isolation ring 20, and the magnetic fluid inner ring 19 is interference fit with the spindle front section 7.

[0025] like Figure 3 , Figure 6 As shown, a bellows 21 is provided between the reaction chamber 2 and the magnetic fluid 5, and the lower end of the bellows 21 is connected to the center of the top of the reaction chamber 2 through an insulating spacer 22, and the insulating spacer 22 is connected to the top of the reaction chamber 2 through bolts, and an insulating sleeve is provided on the outer periphery of the bolts. The upper end of the bellows 21 is in contact with the outer ring 18 of the magnetic fluid and is connected by a seal. Thus, after the bellows 21 wraps the front section 7 of the main shaft that can be lifted and lowered, it forms a vacuum chamber of the vacuum furnace together with the reaction chamber 2. At the same time, the bellows 21, the front section 7 of the main shaft, and the shaft coupling 11 of the coupling 9 form the same conductor together. This same conductor is insulated from the reaction chamber 2 and other related components, and plays a role in conducting the physical signals detected in the reaction chamber 2.

[0026] like Figure 2 , Figure 7As shown, the sliding wire ring 6 is installed on the exposed part of the main shaft front section 7 at the upper end of the magnetic fluid 5, and includes an outer ring body 23 and an inner ring body 24 that can rotate relative to the outer ring body 23, wherein the inner ring body 24 cooperates with the main shaft front section 7 and forms the same rotating body, and the outer periphery of the outer ring body 23 is provided with a U fork block, and a rotation-blocking rod 25 is engaged in the U fork block, and the end of the rotation-blocking rod 25 is fixed to the mounting base 26. Thus, the rotation of the outer ring body 23 can be prevented by the rotation-blocking rod 25 to keep the outer ring body 23 and the mounting base 26 relatively still. In addition, the inner ring body 24 of the sliding wire ring 6 is connected to the main shaft front section 7 through an input line, and together constitutes the signal collection and transmission wire in the furnace. The outer ring body 23 of the sliding wire ring 6 is connected to the external electrical cabinet through an output line, and the collected physical signal in the furnace is transmitted to the electric control module for further conversion and processing. Therefore, the physical electrical signals collected in the reaction chamber 2 by the spindle front section 7 can be transmitted to the outside of the chamber, and then converted into a static state relative to the furnace body by the external sliding wire ring 6, and transmitted to the data acquisition module in the electric control cabinet by the external wire, and then processed and controlled by the furnace control system to ensure the smooth operation of crystal growth.

[0027] With respect to the above signal transmission conversion, the application scenarios of the present invention are as follows: In the process of crystal growth and preparation, the main methods for growing silicon carbide crystals are physical vapor transport (PVT), high-temperature chemical vapor deposition, liquid phase method, etc. Among them, the PVT method is the current large-scale silicon carbide crystal growth method. Liquid phase SiC crystal growth technology has many advantages, including high crystal quality and low cost, and has received great attention in recent years. At present, the liquid phase method has not yet achieved industrial large-scale production. One of the technical difficulties is how to accurately control the height of the molten liquid level in the high-temperature furnace, and then control the movement of the seed crystal axis.

[0028] The present invention utilizes the change in resistance between the seed crystal and the molten solution from separation to infinite proximity to the approaching moment to reflect the actual height of the molten liquid surface, and then controls the movement of the seed crystal to perform pulling crystallization.

[0029] The circuit structure of the resistance signal generated when the seed crystal approaches the molten liquid surface is as follows: a stable power supply is loaded between the furnace shell and the spindle front section 7, the seed crystal shaft is installed at the front end of the spindle front section 7, the crucible and the molten solution therein form the same conductor with the furnace shell, and when the front end of the seed crystal shaft is not in contact with the molten liquid surface in the crucible, this detection circuit is in an open circuit state; when the seed crystal rod spindle system slowly descends, from separation to infinite proximity and finally to the approaching moment, the detection circuit is converted from an open circuit state to a closed circuit state, and at this time, the resistance value of the detection circuit also undergoes a sudden change, thereby inferring the actual position height of the molten liquid surface.

[0030] This application of detecting physical quantities in special environments uses a part of the equipment body structure as a conductor for signal transmission to transmit the physical signal in the special environment to be controlled by the control system. There are many applications similar to this structure, such as float level detection signal transmission, environmental granularity detection signal transmission, etc.

[0031] In the present invention, the wire slide ring 6 is arranged outside the reaction chamber 2, which avoids the stringent requirements of the complex environment in the reaction chamber 2, ensures that the chamber environment is free from pollution, and also ensures the reliable stability of signal conversion.

[0032] In the description of the present invention, the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "vertical", "horizontal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the purpose of describing the present invention rather than requiring the present invention to be constructed or operated in a specific position, and therefore should not be construed as limiting the present invention. The terms "connected" and "connected" in the present invention should be understood in a broad sense, for example, it can be a connection or a detachable connection; it can be a direct connection or an indirect connection through an intermediate component. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0033] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in their embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novelties disclosed herein.

Claims

1. An electrical signal transmission structure for a rotating spindle of a high-temperature vacuum furnace, comprising a frame structure (1), a reaction chamber (2) and a spindle assembly (3), characterized in that: A mounting base (26) is provided on one side of the frame structure (1), and the mounting base (26) includes two mounting plates, one of which is fixed with a spindle motor (4), and the other mounting plate is used to rotatably mount the spindle assembly (3) via a magnetic fluid (5), one end of the spindle assembly (3) is connected to the spindle motor (4), and the other end of the spindle assembly (3) is located in the reaction chamber (2); a sliding wire ring (6) is also installed on the outside of the spindle assembly (3), and the sliding wire ring (6) is located between the two mounting plates of the mounting base (26).

2. The electrical signal transmission structure of the rotating spindle of a high-temperature vacuum furnace according to claim 1, characterized in that: The magnetic fluid (5) comprises a magnetic fluid outer ring (18) and a magnetic fluid inner ring (19), wherein an insulating isolation ring (20) is provided between the magnetic fluid outer ring (18) and a mounting plate of a mounting base (26), and the magnetic fluid inner ring (19) is interference fit with the main shaft assembly (3).

3. The electrical signal transmission structure of the rotating spindle of a high-temperature vacuum furnace according to claim 2, characterized in that: A bellows (21) is provided between the reaction chamber (2) and the magnetic fluid (5); the bellows (21) is nested in the outer periphery of the spindle assembly (3); one end of the bellows (21) is sealedly connected to the center of the top of the reaction chamber (2) via an insulating spacer (22); and the other end of the bellows (21) is sealedly connected to the magnetic fluid (5).

4. The electrical signal transmission structure of the rotating spindle of a high-temperature vacuum furnace according to any one of claims 1 to 3, characterized in that: The spindle assembly (3) comprises a spindle front section (7) and a spindle rear section (8), wherein the spindle rear section (8) is connected to a motor, the spindle front section (7) is rotatably mounted on a mounting plate of a mounting base (26) and is connected to the spindle rear section (8) via a coupling (9), and a sliding wire ring (6) is mounted on the outside of the spindle front section (7).

5. The electrical signal transmission structure of the rotating spindle of a high-temperature vacuum furnace according to claim 4, characterized in that: The coupling (9) comprises a main coupling body (10), a secondary coupling body (11) and an elastic connecting piece (12); the main coupling body (10) is fixed to the rear section (8) of the main shaft, the secondary coupling body (11) is fixed to the front section (7) of the main shaft, and the elastic connecting piece (12) is an insulator.

6. The electrical signal transmission structure of the rotating spindle of a high-temperature vacuum furnace according to claim 5, characterized in that: The sliding wire ring (6) comprises an outer ring body (23) and an inner ring body (24) which can rotate relative to the outer ring body (23); the inner ring body (24) is nested outside the front section of the rotating shaft and forms a rotating body; a U-shaped fork block is provided at the edge of the outer ring body (23); a rotation-blocking rod (25) is engaged in the U-shaped fork block; and an end of the rotation-blocking rod (25) is fixed to a mounting base (26).

7. The electrical signal transmission structure of the rotating spindle of a high-temperature vacuum furnace according to claim 6, characterized in that: The inner ring body (24) of the sliding wire ring (6) is connected to the main shaft assembly (3) via an input line, and the outer ring body (23) of the sliding wire ring (6) is connected to an external electrical cabinet via an output line.

8. The electrical signal transmission structure of the rotating spindle of a high-temperature vacuum furnace according to claim 4, characterized in that: The main shaft rear section (8) and the main shaft front section (7) both have a hollow passage, the hollow passage of the main shaft front section (7) is in communication with the reaction chamber (2), and a quartz lens (13) for passing infrared light is sealed and installed at one end of the main shaft front section (7) away from the reaction chamber (2).

9. The electrical signal transmission structure of the rotating spindle of a high-temperature vacuum furnace according to claim 8, characterized in that: One side of the quartz lens (13) is matched with the end of the main shaft front section (7) through a sealing ring (15), and the other side of the quartz lens (13) is pressed toward the sealing ring (15) through a sealing flange (16).

10. The electrical signal transmission structure of the rotating spindle of a high-temperature vacuum furnace according to claim 8, characterized in that: The front section (7) of the main shaft is also provided with an annular cavity, and the cavity is connected to a guide pipe (17) for cooling water to flow.

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