Motor integrated variable vacuum capacitor

Abstract

The utility model discloses a motor integrated variable vacuum capacitor, which comprises a vacuum capacitor and a motor, the vacuum capacitor comprises two electrode groups and a positioning rod fixed on one electrode group, and an output shaft of the motor is directly connected with the positioning rod in a threaded manner. The motor is used for driving the positioning rod to do linear motion in the axial direction through the output shaft so as to change the relative position of the two electrode sets. According to the utility model, by adopting the integrated structure design and installation mode that the output shaft of the motor is directly connected with the positioning rod of the vacuum capacitor, the influence of connecting pieces and mutual fit clearances thereof on the position of an electrode group of the variable vacuum capacitor is reduced, the capacitance precision of the variable vacuum capacitor is improved, and the volume of the variable vacuum capacitor is greatly reduced; and meanwhile, the manufacturing cost is reduced, and the requirements on high capacitance precision and miniaturization of the variable vacuum capacitor in the field of semiconductor manufacturing equipment are met.

Description

Technical Field

[0001] This utility model relates to the field of capacitor technology, and in particular to a variable vacuum capacitor integrated with a motor. Background Technology

[0002] In variable vacuum capacitors, the moving electrode group is typically connected to a motor via an internal positioning rod and connector. The motor drives the connector to rotate, which in turn moves the positioning rod up and down, changing the coupling length between the two electrode groups and thus adjusting the capacitance value. In RF impedance matching circuits, the capacitance value directly affects the output power of the RF power supply. Therefore, stable and consistent capacitance changes are a key requirement for semiconductor manufacturing equipment manufacturers of variable vacuum capacitors.

[0003] The capacitance of a variable vacuum capacitor is typically reflected by two parameters: one is the capacitance value corresponding to the motor rotation angle and the capacitor's capacitance at a given position, and the other is the capacitance value when the motor rotates clockwise and counterclockwise to the same position. Currently, most users require that the percentage difference in capacitance value at the position during repeated adjustments be no greater than ±2%. Simultaneously, the percentage difference in capacitance value when the motor rotates clockwise and counterclockwise to the same position should be ≤0.5%.

[0004] As semiconductor chips become increasingly integrated, semiconductor manufacturing equipment demands more stable output power from RF impedance matching devices. This necessitates increasingly stable and controllable capacitance variations in variable vacuum capacitors, placing higher demands on these two capacitance accuracy parameters. Simultaneously, to reduce the overall manufacturing cost of semiconductor equipment, variable vacuum capacitors require smaller sizes.

[0005] In existing technologies, such as the variable capacitor connection structure disclosed in Publication No. CN222672823U, published on March 25, 2025, includes a mounting bracket, a bearing, and a connector. The mounting bracket is an integral structure used to fix the variable capacitor between the drive motor and the housing. The bearing is embedded in the mounting bracket and used to support the screw of the variable capacitor. The connector is built into the mounting bracket and used to fix the output shaft of the drive motor to the screw. It is evident that the connection between the traditional variable vacuum capacitor and the motor is very complex and requires high tolerances and fit clearances for each component. Due to the influence of component machining accuracy, the cumulative tolerance after assembling the connecting components is typically between 0.2mm and 0.4mm. Therefore, the coaxiality difference between the positioning rod on the moving electrode assembly and the motor output shaft causes significant fluctuations in the capacitance value of the variable vacuum capacitor and also leads to an increase in the size of the variable vacuum capacitor, making it difficult to meet users' demands for high capacitance accuracy and miniaturization. Therefore, it is necessary to improve the existing technology to overcome its shortcomings. Utility Model Content

[0006] The problem to be solved by this utility model is to provide an integrated variable vacuum capacitor for motors, so as to overcome the defects of traditional variable vacuum capacitors, which have large capacitance fluctuations and large size due to the complex connection between the variable vacuum capacitor and the motor.

[0007] The technical solution adopted by this utility model to solve its technical problem is: an integrated variable vacuum capacitor, comprising: a vacuum capacitor and a motor, wherein the vacuum capacitor includes two electrode groups and a positioning rod fixed to one of the electrode groups, the output shaft of the motor is directly connected to the positioning rod by a thread, and the motor is used to drive the positioning rod to move linearly along the axial direction through the output shaft to change the relative position of the two electrode groups.

[0008] As a further improvement of this utility model, one end of the positioning rod is provided with a threaded hole along the axial direction, and the outer cylindrical surface of the output shaft is provided with an external thread that matches the threaded hole, and the output shaft is threadedly connected to the threaded hole.

[0009] As a further improvement of this utility model, the vacuum capacitor also includes a base, and the motor is fixedly mounted on the base, thereby forming a motor-vacuum capacitor integration.

[0010] As a further improvement of this utility model, the base is provided with a first mounting hole and a second mounting hole. The first mounting hole is used for the vacuum capacitor to fix itself in an external working position, and the second mounting hole is used to fix the motor.

[0011] As a further improvement of this utility model, one of the two electrode groups is a moving electrode group. The moving electrode group includes a moving sub-disc and a moving electrode ring group fixed to the moving sub-disc. The moving sub-disc and the base are sealed and connected by a bellows. The positioning rod is fixedly connected to the moving sub-disc and passes through the bellows.

[0012] As a further improvement of this utility model, the other of the two electrode groups is a fixed electrode group, which includes a stator disk and a fixed electrode ring group fixed to the stator disk; the vacuum capacitor also includes an insulating shell, the stator disk and the base are respectively sealed and fixedly connected to the two ends of the insulating shell, so that the moving disk, the stator disk, the base, the bellows and the insulating shell together form a vacuum chamber, and the moving electrode ring group and the fixed electrode ring group are both housed in the vacuum chamber and can be coupled to each other through the electric field formed therebetween.

[0013] As a further improvement of this utility model, both the moving electrode ring group and the fixed electrode ring group are composed of multiple electrode rings made of metal material arranged concentrically at intervals, and the electrode rings of the moving electrode ring group and the electrode rings of the fixed electrode ring group are alternately and concentrically arranged in the vacuum chamber.

[0014] As a further improvement of this utility model, a guide sleeve is provided on the base, and the positioning rod is slidably fitted inside the guide sleeve.

[0015] As a further improvement of this utility model, the integrated variable vacuum capacitor for motor also includes a control circuit board electrically connected to the motor, and the control circuit board is fitted with a protective box for shielding electromagnetic interference.

[0016] As a further improvement of this utility model, the internal thread of the positioning rod and the external thread of the output shaft are both coated with lubricant.

[0017] The beneficial effects of this utility model are as follows: This utility model provides an integrated variable vacuum capacitor for motors. By directly screwing the output shaft of the motor into the positioning rod, other connecting parts are eliminated, reducing the influence of connecting parts and their mutual clearance on the position of the variable vacuum capacitor electrode group. This makes the capacitance adjustment more controllable and significantly improves the capacitance control accuracy. At the same time, it greatly simplifies the connection structure between the vacuum capacitor and the motor, reduces the processing difficulty and cost, and significantly shortens the overall height of the product. This further reduces the impact of motor output shaft vibration on the capacitance value, thereby further improving the capacitance control accuracy of the vacuum capacitor and meeting the user's demand for high capacitance accuracy and miniaturization of variable vacuum capacitors. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a perspective view of the integrated variable vacuum capacitor for motors according to this utility model;

[0020] Figure 2 This is a cross-sectional view of the integrated variable vacuum capacitor for motors of this utility model;

[0021] Figure 3 This is a perspective view of another embodiment of the integrated variable vacuum capacitor for motors according to this utility model.

[0022] Referring to the accompanying drawings, the following explanations are provided:

[0023] 1. Vacuum capacitor; 11. Positioning rod; 111. Threaded hole; 12. Moving electrode assembly; 121. Moving disk; 122. Moving electrode ring assembly; 13. Stable electrode assembly; 131. Stable disk; 132. Stable electrode ring assembly; 14. Base; 141. First mounting hole; 15. Bellows; 16. Insulating shell; 17. Guide sleeve; 2. Motor; 21. Output shaft; 3. Control circuit board; 4. Protective box. Detailed Implementation

[0024] The present application will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0025] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0027] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The illustrations only show the components related to this application and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0028] Additionally, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that practice can be carried out without these specific details.

[0029] The technical solutions provided by the various embodiments of this application are described below with reference to the accompanying drawings.

[0030] See Figures 1 to 3 This utility model provides an integrated variable vacuum capacitor for a motor, comprising: a vacuum capacitor 1 and a motor 2. The vacuum capacitor 1 includes two electrode groups and a positioning rod 11, wherein at least one of the two electrode groups is adjustable in position within the vacuum capacitor 1, thereby allowing the capacitance of the vacuum capacitor 1 to be adjusted.

[0031] As an important improvement of this application, the positioning rod 11 is fixed to one of the electrode groups, and the output shaft 21 of the motor 2 (i.e. the motor shaft) is directly connected to the positioning rod 11 by a thread. The motor 2 is used to drive the positioning rod 11 to move linearly along the axial direction through the output shaft 21, so as to change the relative position of the two electrode groups, that is, to change the coupling length between the two electrode groups, and realize the function of capacitance adjustment. This invention eliminates other connecting parts by directly screwing the output shaft 21 of the motor 2 into the positioning rod 11, greatly reducing the impact of cumulative tolerances. The capacitance change of the vacuum capacitor 1 is only affected by the rotation angle of the motor 2 and the clearance between the output shaft 21 and the positioning rod 11, making capacitance adjustment more controllable and significantly improving capacitance control accuracy. At the same time, eliminating complex connecting parts greatly simplifies the connection structure between the vacuum capacitor 1 and the motor 2, reducing the number of parts and assembly steps. This correspondingly reduces the high-precision machining requirements caused by the cooperation of multiple parts, lowers the machining difficulty and cost, and significantly shortens the overall height of the product, further reducing the impact of vibration of the output shaft 21 of the motor 2 on the capacitance value. This further improves the capacitance control accuracy of the vacuum capacitor 1, meeting the user's demand for high capacitance accuracy and miniaturization of variable vacuum capacitors.

[0032] See Figure 2 The upper end of the positioning rod 11 is provided with a threaded hole 111 along the axial direction, and the outer cylindrical surface of the output shaft 21 is provided with an external thread that is adapted to the threaded hole 111. The output shaft 21 is threadedly connected to the threaded hole 111.

[0033] The internal thread of the positioning rod 11 and the external thread of the output shaft 21 have the same specifications. The specific parameters of the internal thread of the positioning rod 11 and the external thread of the output shaft 21 can be designed according to the capacitance adjustment requirements, capacitance accuracy requirements, and mechanical life requirements of the vacuum capacitor 1. The parameters of the internal thread of the positioning rod 11 and the external thread of the output shaft 21 include, but are not limited to, thread accuracy, fit clearance, thread diameter, and pitch.

[0034] In addition, the internal thread of the positioning rod 11 and the external thread of the output shaft 21 are coated with lubricant, which can be lubricating grease, to reduce the friction between the threads of the positioning rod 11 and the output shaft 21.

[0035] Furthermore, the vacuum capacitor 1 also includes a base 14, on which the motor 2 is directly fixedly mounted, thus forming an integrated motor-vacuum capacitor system. This integrated motor-vacuum capacitor design has a greater advantage in terms of space occupancy, effectively reducing the product size and making it more suitable for users' needs for miniaturization, which is beneficial for the use of the product in space-constrained application scenarios.

[0036] The base 14 is provided with a first mounting hole 141 and a second mounting hole. Multiple first mounting holes 141 can be provided as needed, and these holes are arranged in a ring with equal spacing near the edge of the upper surface of the base 14. The first mounting holes 141 are used to fix the vacuum capacitor 1 to its external working position. Similarly, multiple second mounting holes (not shown in the figure) are provided, and these holes are evenly distributed in the middle of the upper surface of the base 14, used to fix the motor 2.

[0037] In this embodiment, both the first mounting hole 141 and the second mounting hole are screw holes.

[0038] Continue reading Figure 2 One of the two electrode groups is a moving electrode group 12, and the other is a fixed electrode group 13. The moving electrode group 12 includes a moving sub-disc 121 and a moving electrode ring group 122, and the fixed electrode group 13 includes a stator disc 131 and a fixed electrode ring group 132. The moving sub-disc 121 and the stator disc 131 are vertically opposite each other and parallel to each other. The moving electrode ring group 122 and the fixed electrode ring group 132 are respectively fixed to the inner end faces of the moving sub-disc 121 and the stator disc 131 facing each other.

[0039] The vacuum capacitor 1 also includes a bellows 15 and an insulating shell 16. The insulating shell 16 is a cylindrical shape with open ends, usually made of ceramic material. The base 14 and the stator disk 131 are respectively sealed and fixedly connected to the two ends of the insulating shell 16 by high-temperature brazing. The bellows 15 is sealed between the moving disk 121 and the base 14, so that the moving disk 121, the stator disk 131, the base 14, the bellows 15 and the insulating shell 16 together form a vacuum chamber, in which the moving electrode ring assembly 122 and the stationary electrode ring assembly 132 are both housed.

[0040] The moving electrode ring group 122 and the fixed electrode ring group 132 are both composed of multiple electrode rings made of metal materials (such as oxygen-free copper) arranged concentrically at intervals. The electrode rings of the moving electrode ring group 122 and the electrode rings of the fixed electrode ring group 132 are alternately and concentrically arranged in the vacuum chamber so that the electrode rings of the moving electrode ring group 122 and the electrode rings of the fixed electrode ring group 132 can couple with each other through the electric field formed therebetween.

[0041] Furthermore, the positioning rod 11 is fixedly connected to the moving plate 121 and passes through the bellows 15. Since the moving plate 121 is fixed to the base 14 through the bellows 15, the circumferential movement of the positioning rod 11 fixedly connected to the moving plate 121 is restricted. Under the telescoping action of the bellows 15, the positioning rod 11 can drive the moving electrode assembly 12 to move up and down.

[0042] When the motor 2 is working, the output shaft 21 starts to rotate. With the external thread of the output shaft 21 and the internal thread of the positioning rod 11, the rotational motion is converted into linear motion, which in turn drives the positioning rod 11 to move up and down. At the same time, the positioning rod 11 drives the moving electrode group 12 to move up and down, thereby changing the coupling length between the electrode ring of the moving electrode ring group 122 and the electrode ring of the fixed electrode ring group 132, thus realizing the function of changing the capacitance value.

[0043] It is worth mentioning that a guide sleeve 17 is also provided on the base 14, and the positioning rod 11 is coaxially slidably fitted in the guide sleeve 17 to provide guidance for the up and down movement of the positioning rod 11, while ensuring that the moving electrode group 12 does not undergo radial displacement, ensuring the concentricity of the moving electrode group 12 and the fixed electrode group 13, thereby ensuring the capacitance accuracy of the vacuum capacitor 1.

[0044] This invention does not specify the type of motor 1; for example, it can be a stepper motor or a servo motor, etc.

[0045] In addition, the integrated variable vacuum capacitor of this utility model also includes a control circuit board 3, which is electrically connected to the motor 2 through a power line and a data transmission line.

[0046] In the circuit using a variable vacuum capacitor, the fixed electrode group 13 is typically connected to the high-voltage end, while the base 14, connected to the moving electrode group 12, is grounded. Since the variable vacuum capacitor operates at radio frequency, to prevent the alternating electromagnetic field around the capacitor from affecting the control circuit board 3 of the motor 2, this invention includes a protective box 4 for shielding electromagnetic interference mounted on the control circuit board 3. The protective box 4 can be made of metal. The power cord and data transmission line of the motor 2 pass through the protective box 4 and connect to the control circuit board 3. The protective box 4 has mounting holes, allowing adjustment of the length of the power cord and data transmission line according to the user's installation requirements. The protective box 4 can be directly fixed to one side of the motor 2 (e.g., ...). Figure 1 As shown), the protective box 4 can also be installed in any position within the matcher (e.g., Figure 3 (As shown). This design not only prevents electromagnetic interference but also facilitates the installation of control circuit board 3.

[0047] In summary, this utility model of an integrated variable vacuum capacitor for motors eliminates other connecting parts by directly screwing the output shaft 21 of the motor 2 onto the positioning rod 11. This reduces the influence of connecting parts and their interlocking gaps on the position of the variable vacuum capacitor electrode group, making capacitance adjustment more controllable and significantly improving capacitance control accuracy. Simultaneously, it greatly simplifies the connection structure between the vacuum capacitor 1 and the motor 2, reducing processing difficulty and cost. Furthermore, it significantly shortens the overall product height, further reducing the impact of vibration on the output shaft 21 of the motor 2 on the capacitance value. This further enhances the capacitance control accuracy of the vacuum capacitor 1, meeting users' demands for high capacitance accuracy and miniaturization in variable vacuum capacitors.

[0048] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A variable vacuum capacitor integrated with a motor, comprising a vacuum capacitor (1) and a motor (2), wherein the vacuum capacitor (1) comprises two electrode groups and a positioning rod (11) fixed to one of the electrode groups, characterized in that: The output shaft (21) of the motor (2) is directly connected to the positioning rod (11) by a thread. The motor (2) is used to drive the positioning rod (11) to move linearly along the axial direction through the output shaft (21) to change the relative position of the two electrode groups.

2. The integrated variable vacuum capacitor for motors according to claim 1, characterized in that: One end of the positioning rod (11) is provided with a threaded hole (111) along the axial direction, and the outer cylindrical surface of the output shaft (21) is provided with an external thread that matches the threaded hole (111). The output shaft (21) is threadedly connected to the threaded hole (111).

3. The integrated variable vacuum capacitor for motors according to claim 1, characterized in that: The vacuum capacitor (1) also includes a base (14), and the motor (2) is fixedly mounted on the base (14), thereby forming a motor-vacuum capacitor integrated unit.

4. The integrated variable vacuum capacitor for motors according to claim 3, characterized in that: The base (14) is provided with a first mounting hole (141) and a second mounting hole. The first mounting hole (141) is used for the vacuum capacitor (1) to fix itself in an external working position, and the second mounting hole is used to fix the motor (2).

5. The integrated variable vacuum capacitor for motors according to claim 3, characterized in that: One of the two electrode groups is a moving electrode group (12), which includes a moving sub-disc (121) and a moving electrode ring group (122) fixed to the moving sub-disc (121). The moving sub-disc (121) and the base (14) are sealed together by a bellows (15). The positioning rod (11) is fixedly connected to the moving sub-disc (121) and passes through the bellows (15).

6. The integrated variable vacuum capacitor for motors according to claim 5, characterized in that: The other of the two electrode groups is a fixed electrode group (13), which includes a stator disk (131) and a fixed electrode ring group (132) fixed to the stator disk (131). The vacuum capacitor (1) also includes an insulating shell (16). The stator disk (131) and the base (14) are respectively sealed and fixedly connected to the two ends of the insulating shell (16), so that the moving disk (121), the stator disk (131), the base (14), the bellows (15) and the insulating shell (16) together form a vacuum chamber. The moving electrode ring group (122) and the fixed electrode ring group (132) are both housed in the vacuum chamber and can be coupled to each other through the electric field formed therebetween.

7. The integrated variable vacuum capacitor for motors according to claim 6, characterized in that: Both the moving electrode ring group (122) and the fixed electrode ring group (132) are composed of multiple electrode rings made of metal material arranged concentrically at intervals, and the electrode rings of the moving electrode ring group (122) and the electrode rings of the fixed electrode ring group (132) are arranged alternately and concentrically in the vacuum chamber.

8. The integrated variable vacuum capacitor for motors according to claim 3, characterized in that: A guide sleeve (17) is provided on the base (14), and the positioning rod (11) is slidably fitted inside the guide sleeve (17).

9. The integrated variable vacuum capacitor for motors according to claim 1, characterized in that: It also includes a control circuit board (3) electrically connected to the motor (2), and the control circuit board (3) is fitted with a protective box (4) for shielding electromagnetic interference.

10. The integrated variable vacuum capacitor for motors according to claim 2, characterized in that: The internal thread of the positioning rod (11) and the external thread of the output shaft (21) are both coated with lubricant.

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