A motor system integrated with overvoltage protection function

Abstract

The present application discloses a motor system integrated with an overvoltage protection function. The motor system includes a driver, a servo motor, and a motor cable. The driver is configured to be made of wide-bandgap semiconductor power devices. The servo motor is configured to be controllable by the driver. The motor cable is used to connect the driver and the servo motor so that the driver can control the servo motor through the motor cable. The servo motor includes a motor housing, a stator, a rotor, windings, a rotating shaft, and an overvoltage protection device. The overvoltage protection device is at least partially located within the motor housing, and the overvoltage protection device is electrically connected to the windings. The motor housing includes a connection hole, and the motor cable passes through the connection hole and is electrically connected to the overvoltage protection device so that the motor cable and the windings are configured to be electrically connected through the overvoltage protection device. Through the above arrangement, the integration of the motor system and the response speed of the overvoltage protection device can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of motor protection, and in particular to a motor system integrated with an overvoltage protection function. Background Art

[0002] A motor system generally includes a driver, a motor, and a cable for connecting the driver and the motor. To improve the control performance of the driver, wide-bandgap semiconductor power devices are used to make the driver have the characteristics of fast switching. However, the fast-switching characteristic of the above-mentioned driver will generate a high voltage change rate on the motor side, resulting in a large long-line reflection effect when the motor and the driver are connected by a long cable, and then causing the problem of overvoltage at the motor terminal. This overvoltage not only affects the running stability of the motor, but also accelerates the aging of the motor and shortens its service life.

[0003] In the prior art, an overvoltage protection device, such as a filter, is usually installed outside the motor. The filter can reduce the high-frequency components in the line, thereby reducing the reflected overvoltage to protect the motor from overvoltage. However, this method of installing an overvoltage protection device externally will result in a low integration degree of the motor system, leading to a high space occupancy rate of the motor system, which is not conducive to the layout of the motor system. Moreover, installing an overvoltage protection device externally will also reduce the response speed of the overvoltage protection device, thereby reducing the safety of the motor system.

[0004] Therefore, how to improve the integration degree and response speed of the overvoltage protection device in the motor system is a technical problem urgently to be solved in this field. Summary of the Invention

[0005] In order to solve the deficiencies of the prior art, the purpose of the present application is to provide a motor system with overvoltage protection having a high integration degree and a high response speed.

[0006] To achieve the above purpose, the present application adopts the following technical solutions:

[0007] A motor system integrating an overvoltage protection function, the motor system comprising a driver, a servo motor, and a motor cable. The driver is configured to be made of wide bandgap semiconductor power devices. The servo motor is configured to be controllable by the driver. The motor cable is used to connect the driver and the servo motor so that the driver can control the servo motor through the motor cable; the servo motor includes a motor housing, a stator, a rotor, windings, a rotating shaft, and an overvoltage protection device. The stator is located within the motor housing and the stator is disposed around the rotor. The rotor is fixed to the rotating shaft. The rotating shaft is at least partially located within the motor housing and the rotating shaft is rotatably connected to the motor housing. The windings are disposed on the stator. The overvoltage protection device is at least partially located within the motor housing and the overvoltage protection device is electrically connected to the windings. The motor housing includes a connection hole through which the motor cable passes and is electrically connected to the overvoltage protection device so that the motor cable and the windings are configured to be electrically connected through the overvoltage protection device.

[0008] Further, the servo motor includes a PCB board disposed around the rotating shaft, the PCB board being located within the motor housing and electrically connected to the windings so that the PCB board is configured to control the windings. The PCB board is fixedly connected to the motor housing, and the overvoltage protection device is mounted on the PCB board and electrically connected to the PCB board so that the motor cable is electrically connected to the windings through the overvoltage protection device and the PCB board; the motor housing has a first volume and a second volume that communicate with each other, the stator, the rotor, and the windings are located within the first volume, the rotating shaft is at least partially located within the first volume and at least partially located within the second volume, the overvoltage protection device is at least partially located within the second volume, and the PCB board is located within the second volume.

[0009] Further, the overvoltage protection device is located at a position on the PCB board close to the connection hole. The overvoltage protection device is located on a side of the PCB board facing away from the windings.

[0010] Further, the servo motor includes a metal bracket located within the motor housing. The metal bracket is fixedly connected to the motor housing, and the overvoltage protection device is mounted on the metal bracket and electrically connected to the windings so that the motor cable is electrically connected to the windings through the overvoltage protection device. The metal bracket is disposed close to the connection hole; the motor housing has a first volume and a second volume that communicate with each other, the stator, the rotor, and the windings are located within the first volume, the rotating shaft is at least partially located within the first volume and at least partially located within the second volume, the overvoltage protection device is at least partially located within the second volume, and the metal bracket is located within the second volume.

[0011] Furthermore, the inner wall of the second volume is cylindrical. The metal bracket includes an integrally formed first connection portion, a second connection portion, and a protruding portion. The first connection portion extends along a curved surface, and the radius of curvature of the curved surface is configured such that the first connection portion fits against the inner wall of the second volume. The second connection portion is configured to extend from the first connection portion towards the rotating shaft to form, and the overvoltage protection device is installed on the side of the second connection portion facing away from the winding. The protruding portion is configured to extend from the first connection portion away from the rotating shaft to form, and the protruding portion is at least partially located within the connection hole and is in interference fit with the connection hole. The motor cable is passed through the protruding portion and is electrically connected to the overvoltage protection device.

[0012] Furthermore, the protruding portion is provided with a U-shaped groove. The notch of the U-shaped groove faces the winding, the U-shaped groove extends along the radial direction of the rotating shaft and penetrates through the protruding portion, and the motor cable is passed through the U-shaped groove and is electrically connected to the overvoltage protection device.

[0013] Furthermore, the connection method between the metal bracket and the motor housing is only the interference fit connection between the protruding portion and the connection hole.

[0014] Furthermore, the range of the minimum distance between the overvoltage protection device and the winding is from 3 mm to 10 mm.

[0015] Furthermore, the winding includes a U-phase winding, a V-phase winding, and a W-phase winding; the overvoltage protection device includes a first protection module, a second protection module, and a third protection module. The first protection module, the second protection module, and the third protection module each include a gas discharge tube and a varistor. The gas discharge tube and the varistor of the first protection module are connected in parallel to form a first connection point and a second connection point. The gas discharge tube and the varistor of the second protection module are connected in parallel to form a third connection point and a fourth connection point. The gas discharge tube and the varistor of the third protection module are connected in parallel to form a fifth connection point and a sixth connection point; the first connection point is connected to the U-phase winding, the third connection point is connected to the V-phase winding, the fifth connection point is connected to the W-phase winding, and the second connection point, the fourth connection point, and the sixth connection point are all grounded.

[0016] Furthermore, the ratio range of the space occupancy rate of the overvoltage protection device to the space occupancy rate of the servo motor is from 2% to 5%.

[0017] In this application, by arranging the overvoltage protection device in the second volume, the integration of the motor system can be improved, and then the space occupancy rate of the motor system can be reduced, which is beneficial to the layout of the motor system. Moreover, through the above arrangement, the signal transmission path between the overvoltage protection device and the servo motor can be shortened, thereby improving the response speed of the overvoltage protection device and further enhancing the safety of the motor system. Description of the Drawings

[0018] Figure 1Schematic diagram of the overall structure of the servo motor in the motor system of the present application;

[0019] Figure 2 Schematic cross-sectional view of the servo motor in the motor system of the present application;

[0020] Figure 3 Schematic diagram of the overall structure of the overvoltage protection device in the motor system of the present application;

[0021] Figure 4 Schematic diagram of the overall structure of the second servo motor in the motor system of the present application;

[0022] Figure 5 Schematic cross-sectional view of the second servo motor in the motor system of the present application;

[0023] Figure 6 Schematic diagram of the overall structure of the second overvoltage protection device in the motor system of the present application;

[0024] Figure 7 Schematic diagram of the structure of the metal bracket in the motor system of the present application;

[0025] Figure 8 Schematic circuit diagram of the overvoltage protection device in the motor system of the present application. Detailed implementation manners

[0026] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the specific implementation manners of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the implementation manners of the present application.

[0027] It should be noted that the "first", "second" and similar terms used in the specification and claims of the present application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, terms such as "a" or "one" do not indicate a quantity limitation, but indicate the existence of at least one. "Multiple" or "several" means at least two. Unless otherwise specified, terms such as "front", "rear", "left", "right", "lower" and / or "upper" are only for convenience of description and are not limited to one position or a spatial orientation. "Including" or "comprising" and similar terms mean that the elements or objects appearing before "including" or "comprising" cover the elements or objects listed after "including" or "comprising" and their equivalents, and do not exclude other elements or objects. "Connect" or "be connected" and similar terms are not limited to physical or mechanical connections, and may include electrical connections, whether direct or indirect.

[0028] As used in the specification and the appended claims of this application, the singular forms "a", "the", and "said" are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0029] As Figure 1 , Figure 2 and Figure 3 shown, this application provides a motor system 100 with overvoltage protection. The motor system 100 includes a driver (not shown in the figure), a servo motor 11, and a motor cable (not shown in the figure). Specifically, the driver is configured to be made of wide-bandgap semiconductor power devices, the servo motor 11 is configured to be controllable by the driver, and the motor cable is used to connect the driver and the servo motor 11 so that the driver can control the servo motor 11 through the motor cable. With such an arrangement, the driver made of wide-bandgap semiconductor power devices has a high breakdown voltage, a high electron mobility, and a low conduction loss, which is beneficial to improving the switching efficiency of the driver in driving the servo motor 11. This application takes the driver being made of SiC (Silicon Carbide) material as an example for illustration. It should be noted that the driver of this application can also be made of other wide-bandgap semiconductor power devices, such as GaN (Gallium Nitride) or ZnO (Zinc Oxide), etc., and this application does not make any restrictions. Among them, the length of the motor cable is less than or equal to 50 m. With such an arrangement, it is beneficial for the driver to remotely control the servo motor 11 to improve the usability of the motor system 100. Moreover, the overvoltage protection device 116 of the motor system 100 in this application can also avoid the situation where the long line reflection effect is too large due to the overly long motor cable, which is beneficial to reducing the occurrence of overvoltage in the servo motor 11 and further improving the operating stability of the servo motor 11.

[0030] Specifically, the servo motor 11 includes a motor housing 111, a stator 112, a rotor 113, windings 114, a rotating shaft 115, and an overvoltage protection device 116. Among them, the stator 112 is located inside the motor housing 111 and is arranged around the rotor 113. The rotor 113 is located inside the motor housing 111 and is fixed to the rotating shaft 115. The rotor 113 is used to generate a magnetic field, and the rotating shaft 115 is rotatably connected to the motor housing 111 through bearings. The rotor 113 can cooperate with the stator 112 to generate a magnetic force and drive the rotating shaft 115 to rotate. The windings 114 are used to generate a magnetic field, and the windings 114 are located inside the motor housing 111 and are arranged on the stator 112. The rotating shaft 115 is used to transmit torque, and the rotating shaft 115 is at least partially located inside the motor housing 111.

[0031] More specifically, the motor housing 111 has a first volume 1111 and a second volume 1112. The first volume 1111 and the second volume 1112 are in communication. The stator 112, the rotor 113, and the winding 114 are located within the first volume 1111. The rotating shaft 115 is at least partially located within the first volume 1111 and at least partially located within the second volume 1112. The overvoltage protection device 116 is at least partially located within the second volume 1112, and the overvoltage protection device 116 is electrically connected to the winding 114. With such an arrangement, the overvoltage protection device 116 can be located within the motor housing 111, and the overvoltage protection device 116 can be integrated within the motor housing 111, which is beneficial to improving the integration of the motor system 100, making the structure of the motor system 100 more compact, and thus reducing the space occupancy of the motor system 100, which is then beneficial to the layout of the motor system 100. Moreover, through the above arrangement, the signal transmission distance between the overvoltage protection device 116 and the winding 114 can be reduced, which is beneficial to improving the response speed of the overvoltage protection device 116 when it senses overvoltage, so that the overvoltage protection device 116 can quickly respond to and process the overvoltage in the circuit, which is beneficial to reducing the burden on the insulation of the winding 114 and thus improving the service life of the servo motor 11. In addition, through the above arrangement, the present application does not need to use a winding 114 with high insulation to avoid the winding 114 being broken down by overvoltage, which is beneficial to reducing the cost of the servo motor 11.

[0032] In this embodiment, the motor housing 111 includes a connection hole 1113. The motor cable passes through the connection hole 1113 and is electrically connected to the overvoltage protection device 116, so that the motor cable and the winding 114 are configured to be electrically connected through the overvoltage protection device 116. With such an arrangement, the connection hole 1113 is beneficial to the connection between the overvoltage protection device 116 and the motor cable, thus avoiding interference of the motor housing 111 with the assembly of the overvoltage protection device 116 and the motor cable, and further being beneficial to improving the assembly convenience of the overvoltage protection device 116.

[0033] In the present application, the overvoltage protection device 116 is detachably connected to the winding 114. With such an arrangement, the overvoltage protection device 116 can be disassembled and replaced on the servo motor 11, which is beneficial to the upgrade and maintenance of the overvoltage protection device 116. Moreover, through the above arrangement, the user can flexibly replace the overvoltage protection device 116 according to requirements, so as to improve the flexibility of use of the motor system 100. In some embodiments, the overvoltage protection device 116 is connected to the winding 114 by pins. With such an arrangement, while the electrical connection between the overvoltage protection device 116 and the winding 114 can be achieved through the pins, it is also beneficial to the disassembly and assembly between the overvoltage protection device 116 and the winding 114. It should be noted that the overvoltage protection device 116 and the winding 114 can also be connected by other detachable electrical connection methods, and the present application does not make any restrictions.

[0034] As an implementation manner, the servo motor 11 includes a PCB board 117 disposed around the rotating shaft 115. The PCB board 117 is located inside the motor housing 111 and is electrically connected to the winding 114, so that the PCB board 117 is configured to be able to control the winding 114. Specifically, the PCB board 117 is fixedly connected to the motor housing 111, and the overvoltage protection device 116 is installed on the PCB board 117 and electrically connected to the PCB board 117, so that the motor cable is electrically connected to the winding 114 through the overvoltage protection device 116 and the PCB board 117. More specifically, the PCB board 117 is located in the second volume 1112. With such an arrangement, the overvoltage protection device 116 can be fixed in the second volume 1112 through the PCB board 117, which is beneficial to improving the assembly convenience of the overvoltage protection device 116 and the servo motor 11. In some embodiments, the overvoltage protection device 116 is connected to the PCB board 117 by pins. It can be understood that the pin connection is a detachable connection, which is beneficial to the disassembly and assembly of the overvoltage protection device 116 on the PCB board 117, so that the overvoltage protection device 116 can be flexibly disassembled and assembled on the PCB board 117 according to user requirements.

[0035] It should be noted that the connection manner between the overvoltage protection device 116 and the PCB board 117 can also be other detachable electrical connection methods, and the present application does not make any restrictions.

[0036] Specifically, the overvoltage protection device 116 is located at a position on the PCB board 117 close to the connection hole 1113, and the overvoltage protection device 116 is located on the side of the PCB board 117 facing away from the winding 114. Such an arrangement can facilitate the direct connection between the motor cable and the overvoltage protection device 116 after the motor cable passes through the connection hole 1113, thereby shortening the line between the motor cable and the overvoltage protection device 116, reducing the transmission loss and coupling interference of the overvoltage signal, and further improving the response speed of the overvoltage protection device 116. Moreover, such an arrangement can also avoid interference of the PCB board 117 with the motor cable, thereby facilitating the layout of the motor cable within the second volume 1112. In addition, by arranging the overvoltage protection device 116 and the winding 114 on both sides of the PCB board 117, interference of the overvoltage protection device 116 with the magnetic field generated by the winding 114 or interference of the magnetic field generated by the winding 114 with the overvoltage protection device 116 can be avoided, thereby facilitating the improvement of the operating stability of the servo motor 11.

[0037] As Figure 4 and Figure 5 shown, as another embodiment, the servo motor 11 includes a metal bracket 118. The metal bracket 118 is located within the motor housing 111, and the metal bracket 118 is also fixedly connected to the motor housing 111. The overvoltage protection device 116 is mounted on the metal bracket 118 and electrically connected to the winding 114, so that the motor cable is electrically connected to the winding 114 through the overvoltage protection device 116. Specifically, the metal bracket 118 is located within the second volume 1112. Such an arrangement can enable the overvoltage protection device 116 to be applicable to the high-power servo motor 11 with a wire connection mode between the motor cable and the winding 114 through the metal bracket 118.

[0038] In this embodiment, the metal bracket 118 is arranged close to the connection hole 1113. Such an arrangement can facilitate the direct connection between the motor cable and the overvoltage protection device 116 on the metal bracket 118 after the motor cable passes through the connection hole 1113, thereby shortening the line between the motor cable and the overvoltage protection device 116, reducing the transmission loss and coupling interference of the overvoltage signal, and thus improving the response speed of the overvoltage protection device 116.

[0039] As Figure 6 and Figure 7 shown, as an alternative implementation, the second volume 1112 (refer to Figure 4) The inner wall of () is cylindrical. The metal bracket 118 includes an integrally formed first connecting portion 1181, a second connecting portion 1182, and a protruding portion 1183. Among them, the first connecting portion 1181 extends along a curved surface, and the radius of curvature of the curved surface is configured to enable the first connecting portion 1181 to fit the inner wall of the second volume 1112. With such a setting, the fitting degree between the metal bracket 118 and the second inner wall can be improved, thereby improving the connection stability between the metal bracket 118 and the motor housing 111 to prevent the metal bracket 118 from shaking and causing the metal bracket 118 to become loose from the winding 114 (refer to Figure 4 ), the overvoltage protection device 116, and the motor cable, which is conducive to improving the connection stability between the metal bracket 118 and the winding 114, the overvoltage protection device 116, and the motor cable, and improving the operating stability of the overvoltage protection device 116.

[0040] Specifically, the second connecting portion 1182 is configured to be formed by the first connecting portion 1181 extending towards the rotating shaft 115. The overvoltage protection device 116 is installed on the side of the second connecting portion 1182 facing away from the winding 114. With such a setting, the overvoltage protection device 116 and the winding 114 can be respectively arranged on both sides of the second connecting portion 1182, thereby preventing the magnetic field generated by the overvoltage protection device 116 from interfering with the magnetic field generated by the winding 114, or preventing the magnetic field generated by the winding 114 from interfering with the overvoltage protection device 116, which is conducive to improving the operating stability of the winding 114 and the overvoltage protection device 116.

[0041] More specifically, the protruding portion 1183 is configured to be formed by the first connecting portion 1181 extending away from the rotating shaft 115. The protruding portion 1183 is at least partially located in the connecting hole 1113 and is in interference fit with the connecting hole 1113. The motor cable passes through the protruding portion 1183 and is electrically connected to the overvoltage protection device 116. With such a setting, through the interference fit between the protruding portion 1183 and the connecting hole 1113, it is beneficial to fixedly connect the metal bracket 118 and the motor housing 111, thereby improving the connection stability between the metal bracket 118 and the motor housing 111. In addition, the interference fit method is also beneficial to the disassembly and assembly of the metal bracket 118 at the connecting hole 1113, which is conducive to replacing the overvoltage protection device 116 on the metal bracket 118, and thus the overvoltage protection device 116 can be flexibly installed according to the user's usage requirements.

[0042] As an alternative implementation, the convex portion 1183 is provided with a U-shaped groove 1183a. The notch of the U-shaped groove 1183a faces the winding 114. The U-shaped groove 1183a extends radially along the rotating shaft 115 and penetrates through the convex portion 1183. The motor cable is disposed in the U-shaped groove 1183a and electrically connected to the overvoltage protection device 116. With such an arrangement, the U-shaped groove 1183a can provide a deformation space for the deformation of the convex portion 1183, thereby facilitating the interference fit connection of the convex portion 1183 with the connection hole 1113.

[0043] In this embodiment, the connection mode between the metal bracket 118 and the motor housing 111 is only the interference fit connection between the convex portion 1183 and the connection hole 1113. With such an arrangement, it can be ensured that the metal bracket 118 and the motor housing 111 do not need to be connected by fasteners or other fixing devices, and the motor housing 111 does not need to be opened, which is beneficial to simplifying the structure of the servo motor 11, reducing the processing difficulty of the motor housing 111, and improving the assembly convenience of the convex portion 1183 and the motor housing 111. At the same time, the above arrangement can utilize the structure of the connection hole 1113 itself to fix the convex portion 1183 in the connection hole 1113, thereby forming a stable connection between the metal bracket 118 and the motor housing 111.

[0044] In the present application, the range of the minimum distance between the overvoltage protection device 116 and the winding 114 is 3 mm to 10 mm. With such an arrangement, it can be avoided that when the minimum distance between the overvoltage protection device 116 and the winding 114 is less than 3 mm, the overvoltage protection device 116 interferes with the magnetic field generated by the winding 114, which is beneficial to improving the operation stability of the servo motor 11. And, with such an arrangement, a safe electrical clearance can also be provided for the overvoltage protection device 116 and the winding 114, which is beneficial to the safe operation of the servo motor 11. In addition, it can be avoided that when the minimum distance between the overvoltage protection device 116 and the winding 114 is greater than 10 mm, the overvoltage protection device 116 cannot respond in time or the response rate is slow, which is beneficial to improving the use safety and response efficiency of the motor system 100.

[0045] In some embodiments, a relatively thick copper foil line is used to connect the overvoltage protection device 116 and the winding 114. Specifically, the copper foil line has good electrical conductivity, which can reduce the transmission impedance and delay of the voltage signal, and thus is beneficial to improving the response speed of the overvoltage protection device 116. It should be noted that other lines with good electrical conductivity can also be used to connect the overvoltage protection device 116 and the winding 114, and the present application is not limited thereto.

[0046] Such as Figure 3 、 Figure 6 and Figure 8As shown, as an embodiment, the winding 114 includes a U-phase winding, a V-phase winding, and a W-phase winding. It can be understood that the U-phase winding, the V-phase winding, and the W-phase winding constitute a three-phase winding system.

[0047] Specifically, the overvoltage protection device 116 includes a first protection module 1161, a second protection module 1162, and a third protection module 1163. The first protection module 1161, the second protection module 1162, and the third protection module 1163 each include a gas discharge tube 1164 and a varistor 1165. The gas discharge tube 1164 and the varistor 1165 of the first protection module 1161 are connected in parallel to form a first connection point 1161a and a second connection point 1161b. The gas discharge tube 1164 and the varistor 1165 of the second protection module 1162 are connected in parallel to form a third connection point 1162a and a fourth connection point 1162b. The gas discharge tube 1164 and the varistor 1165 of the third protection module 1163 are connected in parallel to form a fifth connection point 1163a and a sixth connection point 1163b. The first connection point 1161a is connected to the U-phase winding, the third connection point 1162a is connected to the V-phase winding, the fifth connection point 1163a is connected to the W-phase winding, and the second connection point 1161b, the fourth connection point 1162b, and the sixth connection point 1163b are all grounded. Through the above settings, the first protection module 1161, the second protection module 1162, and the third protection module 1163 can respectively perform overvoltage protection on one of the above windings 114, thereby improving the overall protection of the overvoltage protection device for the winding 114, and further improving the use safety of the servo motor 11. Among them, the gas discharge tube 1164 has a high energy absorption capacity and a fast response speed, so that the overvoltage protection device 116 can absorb high-amplitude voltage impulses. The varistor 1165 has good voltage clamping ability and low residual voltage, so that the overvoltage protection device 116 can limit the voltage within a safe range. With such settings, the overvoltage protection device 116 can perform hierarchical protection on the servo motor 11, that is, the gas discharge tube 1164 can withstand overvoltage impulses with a fast voltage change rate in the circuit to perform the first-level protection, and then the varistor 1165 can further limit the residual voltage in the circuit to keep the residual voltage within a safe range, thereby performing the second-level protection. With such settings, the protection effect of the overvoltage protection device 116 against overvoltage can be improved, so that the overvoltage protection device 116 can perform fast and lasting voltage protection on the servo motor 11. In addition, through the above settings, the present application does not need to use a filter as the overvoltage protection device 116 to work, thereby avoiding the increase in the complexity of the motor system 100 caused by adding a filter, and further facilitating the simplification of the overall structure of the motor system 100. Also, it can avoid the situation where the suppression effect of the filter on low-frequency or DC overvoltage is not obvious, thereby facilitating the improvement of the overall protection of the overvoltage protection device 116.

[0048] It should be noted that the overvoltage protection device 116 of the present application may also include only the gas discharge tube 1164 or the varistor 1165, or any combination of the gas discharge tube 1164 and the varistor 1165 in any quantity and form, as long as the overvoltage protection device 116 can meet the usage requirements, and the present application does not make any restrictions.

[0049] As an implementation manner, the ratio range of the space occupancy rate of the overvoltage protection device 116 to the space occupancy rate of the servo motor 11 is 2% to 5%. With such a setting, it can be avoided that when the ratio of the space occupancy rate of the overvoltage protection device 116 to the space occupancy rate of the servo motor 11 is too small, the processing difficulty of the overvoltage protection device 116 is increased, which is beneficial to the production and processing of the overvoltage protection device 116. In addition, it can also be avoided that when the ratio of the space occupancy rate of the overvoltage protection device 116 to the space occupancy rate of the servo motor 11 is too large, it is difficult to assemble the overvoltage protection device 116 into the servo motor 11, thereby facilitating the assembly of the overvoltage protection device 116 and the servo motor 11. Or, it can also be avoided that when the space occupancy rate of the overvoltage protection device 116 is too large, the overvoltage protection device 116 excessively occupies the layout space in the servo motor 11, thereby preventing other components in the servo motor 11 from interfering with the overvoltage protection device 116, and further facilitating the improvement of the working stability of the overvoltage protection device 116.

[0050] It should be understood that for those of ordinary skill in the art, improvements or transformations can be made according to the above description, and all such improvements and transformations should fall within the protection scope of the appended claims of the present application.

Claims

1. A motor system with integrated overvoltage protection function, characterized in that: The motor system comprises: A driver, wherein the driver is configured to be made of a wide bandgap semiconductor power device; a servo motor configured to be controllable by the driver; a motor cable, the motor cable being used to connect the driver and the servo motor so that the driver can control the servo motor through the motor cable; The servo motor comprises a motor housing, a stator, a rotor and a winding located in the motor housing, and a rotating shaft at least partially located in the motor housing, wherein the stator is arranged around the rotor, the rotor is fixed on the rotating shaft, the rotating shaft is rotatably connected to the motor housing, and the winding is arranged on the stator; The servo motor further comprises an overvoltage protection device, the overvoltage protection device is at least partially located in the motor housing, and the overvoltage protection device is electrically connected to the winding; The motor housing comprises a connection hole, the motor cable is passed through the connection hole and is electrically connected to the overvoltage protection device, so that the motor cable and the winding are configured to be electrically connected through the overvoltage protection device; The servo motor comprises a metal bracket, the metal bracket is located in the motor housing, the metal bracket is fixedly connected to the motor housing, and the overvoltage protection device is installed on the metal bracket; the motor housing has a first volume and a second volume, the first volume and the second volume are connected, the stator, the rotor and the winding are located in the first volume, the overvoltage protection device is at least partially located in the second volume, and the metal bracket is located in the second volume; The windings include a U-phase winding, a V-phase winding and a W-phase winding; The overvoltage protection device includes a first protection module, a second protection module and a third protection module. The first protection module, the second protection module and the third protection module all include a gas discharge tube and a varistor. The gas discharge tube and the varistor of the first protection module are arranged in parallel to form a first connection point and a second connection point, the gas discharge tube and the varistor of the second protection module are arranged in parallel to form a third connection point and a fourth connection point, and the gas discharge tube and the varistor of the third protection module are arranged in parallel to form a fifth connection point and a sixth connection point; the first connection point is connected to the U-phase winding, the third connection point is connected to the V-phase winding, the fifth connection point is connected to the W-phase winding, and the second connection point, the fourth connection point and the sixth connection point are all grounded.

2. The motor system according to claim 1, characterized in that: The servo motor comprises a PCB board arranged around the rotating shaft, the PCB board is located in the motor housing and is electrically connected to the winding, so that the PCB board is configured to control the winding, the PCB board is fixedly connected to the motor housing, the overvoltage protection device is installed on the PCB board and is electrically connected to the PCB board, so that the motor cable is electrically connected to the winding through the overvoltage protection device and the PCB board; The motor housing has a first volume and a second volume, the first volume and the second volume are connected, the stator, the rotor and the winding are located in the first volume, the rotating shaft is at least partially located in the first volume and at least partially located in the second volume, the overvoltage protection device is at least partially located in the second volume, and the PCB board is located in the second volume.

3. The motor system according to claim 2, characterized in that: The overvoltage protection device is located at a position of the PCB board close to the connection hole; The overvoltage protection device is located on a side of the PCB board away from the winding.

4. The motor system according to claim 1, characterized in that: The metal bracket is arranged close to the connecting hole; The shaft is at least partially located within the first volume and at least partially located within the second volume.

5. The motor system according to claim 4, characterized in that: The inner wall of the second volume is cylindrical, and the metal bracket includes a first connecting portion, a second connecting portion and a protruding portion which are integrally formed; The first connection portion extends along a curved surface, and the curvature radius of the curved surface is configured to enable the first connection portion to fit the inner wall of the second volume; The second connection portion is configured to be formed by extending the first connection portion toward the rotating shaft, and the overvoltage protection device is installed on a side of the second connection portion away from the winding; The protrusion is configured to be formed by the first connection portion extending away from the rotating shaft, and the protrusion is at least partially located in the connecting hole and has an interference fit with the connecting hole. The motor cable is passed through the protrusion and is electrically connected to the overvoltage protection device.

6. The motor system according to claim 5, characterized in that: The raised portion is provided with a U-shaped groove, the notch of the U-shaped groove is arranged toward the winding, the U-shaped groove extends radially along the rotating shaft and passes through the raised portion, the motor cable is passed through the U-shaped groove and is electrically connected to the overvoltage protection device.

7. The motor system according to claim 5, characterized in that: The metal bracket is connected to the motor housing in the form of an interference fit between the protrusion and the connecting hole.

8. The motor system according to any one of claims 1 to 7, characterized in that: The minimum distance between the overvoltage protection device and the winding ranges from 3 mm to 10 mm.

9. The motor system according to any one of claims 1 to 7, characterized in that: The ratio of the space occupied by the overvoltage protection device to the space occupied by the servo motor ranges from 2% to 5%.

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