A rotor structure and a stepper motor

Abstract

The application belongs to the field of motor technology equipment, and particularly relates to a rotor structure and a stepping motor. The rotor structure comprises a rotating shaft, a first permanent magnet in a circular ring shape and sleeving and connecting the rotating shaft, a magnetic conductor connecting the first permanent magnet, and a rotor core sleeving the magnetic conductor, two of which are arranged at intervals, the first permanent magnet is located between the two rotor cores, the magnetic conductor is provided with two, the two magnetic conductors are respectively located on the two sides of the first permanent magnet, and are respectively arranged corresponding to the two rotor cores, and the magnetic conductor and the adjacent rotor core overlap along the radial surface of the rotating shaft. The application can improve the magnetic field strength of the motor, and enhance the output power and torque of the motor.

Description

Technical Field

[0001] This invention belongs to the field of motor technology and equipment, and particularly relates to a rotor structure and a stepper motor. Background Technology

[0002] A stepper motor is an electric motor that converts electrical pulse signals into discrete stepping motion. It is widely used in many applications due to its precise positioning, high controllability, and ease of control. A stepper motor typically consists of a rotor, stator, magnets, sensors, and drive circuitry.

[0003] With the continuous development of technology, stepper motors are also becoming smaller and more compact, resulting in micro stepper motors. Micro stepper motors are small, compact stepper motors often used in applications with high space requirements. They have many characteristics similar to traditional stepper motors, such as precise positioning, high controllability, and ease of control, but are smaller and lighter.

[0004] However, due to their size, miniature stepper motors generally have low rotor torque output, which often fails to meet the needs of practical applications. Summary of the Invention

[0005] The purpose of this application is to provide a rotor structure that addresses the problem of how to improve the torque output of a rotor structure.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0007] In a first aspect, a rotor structure is provided, comprising: a rotating shaft, a first permanent magnet in an annular shape and connected to the rotating shaft, a magnetic conductor connected to the first permanent magnet, and a rotor core with the magnetic conductor attached to it. Two rotor cores are arranged at intervals. The first permanent magnet is located between the two rotor cores. Two magnetic conductors are provided, each located on one side of the first permanent magnet and corresponding to the two rotor cores. The magnetic conductors overlap with the adjacent rotor cores along the radial surface of the rotating shaft.

[0008] In some embodiments, the inner diameter hole of the rotor core is fitted onto the magnetic conductor, such that the outer diameter of the magnetic conductor overlaps with the radial surface of the inner diameter of the rotor core, and the inner diameter of the magnetic conductor overlaps with the radial surface of the rotating shaft.

[0009] In some embodiments, the rotor structure further includes a second permanent magnet sleeved on the rotating shaft, the outer diameter of the second permanent magnet being smaller than the outer diameter of the first permanent magnet; the magnetization direction of the first permanent magnet is the same as that of the second permanent magnet and both are along the axial direction of the rotating shaft; a second permanent magnet is provided between any of the magnetic conductors and the first permanent magnet, and the two second permanent magnets are respectively located in the inner diameter holes of the two rotor cores.

[0010] In some embodiments, the cross-sectional area of ​​the second permanent magnet gradually decreases in the direction away from the first permanent magnet, and the longitudinal cross-sectional shape of the second permanent magnet is trapezoidal, and the two second permanent magnets are respectively located at the inner ring holes of the two magnetic conductors.

[0011] In some embodiments, the rotor structure further includes a third permanent magnet, wherein the magnetization direction of the first permanent magnet is the same as that of the third permanent magnet and both are along the axial direction of the rotation axis; the first permanent magnet has an inner annular hole, the outer diameter of the third permanent magnet is smaller than the inner diameter of the first permanent magnet, and the inner diameter of the first permanent magnet is fitted onto the outer diameter of the third permanent magnet, and the two ends of the third permanent magnet are respectively adjacent to two magnetic conductors.

[0012] In some embodiments, the two ends of the third permanent magnet are respectively located at the inner ring holes of the two magnetic conductors; the cross-sectional area of ​​any end of the third permanent magnet gradually increases along the direction pointing to the first permanent magnet, and its longitudinal section is trapezoidal.

[0013] In some embodiments, the rotor structure further includes a ring-shaped fourth permanent magnet, the rotation shaft is located inside the fourth permanent magnet and the fourth permanent magnet is concentric with the rotation shaft, the fourth permanent magnet is provided on both sides of the first permanent magnet, and the two fourth permanent magnets are respectively located in the inner diameter holes of the two magnetic conductors; the magnetization direction of the fourth permanent magnet on one side is radially outward along the rotation shaft, and the magnetization direction of the fourth permanent magnet on the other side is radially inward along the rotation shaft; the first permanent magnet is magnetized along the axial direction of the rotation shaft, and the magnetization direction of the first permanent magnet is along the direction of the inwardly magnetized fourth permanent magnet pointing towards the direction of the outwardly magnetized fourth permanent magnet.

[0014] In some embodiments, the rotor structure further includes a cylindrical magnetic guide that is fitted over the rotating shaft. The magnetic guide passes through the inner annular hole of the first permanent magnet, and both ends of the magnetic guide pass through the inner annular holes of the two fourth permanent magnets, respectively.

[0015] Secondly, a stepper motor is provided, the stepper motor including the rotor structure, the stepper motor further including a stator structure that cooperates with the rotor structure, the stator structure including: a stator core sleeved on the rotor core, a frame connected to the stator core and having a slot, a coil winding located in the slot, a protective member surrounding the outer periphery of the coil winding and at least partially located in the slot, and an injection-molded insert molded on the protective member, wherein the two opposite end faces of the frame are covered by the injection-molded insert.

[0016] In some embodiments, the protective member is made of a flexible thin film material and is wrapped around the outer periphery of the coil winding; or the protective member is made of a rigid material and has a protective groove, the coil winding is located in the protective groove, and the protective member is provided at both ends of the groove.

[0017] The beneficial effects of this application are as follows: The rotor structure includes a rotating shaft, a first permanent magnet, a magnetic conductor, and a rotor core. By overlapping the rotor core and the magnetic conductor along the radial direction of the rotating shaft, the magnetic flux generated by the first permanent magnet is concentrated at the rotor core, increasing the magnetic flux at the rotor core. Then, through the magnetic conduction of the rotor core, a closed magnetic circuit is formed, which ultimately increases the magnetic field strength at the rotor core and enhances the output power and torque of the rotor structure. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or exemplary technologies 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 three-dimensional structural schematic diagram of an internal rotor stepper motor provided in one embodiment of this application;

[0020] Figure 2 This is a three-dimensional structural schematic diagram of an internal rotor stepper motor provided in one embodiment of this application;

[0021] Figure 3 yes Figure 2 A cross-sectional view of an internal rotor stepper motor along the rotation axis;

[0022] Figure 4 yes Figure 2 A cross-sectional view of an internal rotor stepper motor along the radial direction of its rotation axis;

[0023] Figure 5 This is a three-dimensional structural diagram of the first permanent magnet and the second permanent magnet provided in one embodiment of this application;

[0024] Figure 6 yes Figure 5 A schematic diagram of the assembly of the second permanent magnet, the magnetic conductor, and the rotor core;

[0025] Figure 7 This is a three-dimensional structural diagram of a second permanent magnet with a gradually decreasing cross-sectional area provided in one embodiment of this application;

[0026] Figure 8 yes Figure 7 A schematic diagram of the assembly of the second permanent magnet with the magnetic conductor and the rotor core;

[0027] Figure 9 This is an exploded schematic diagram of the first and second permanent magnets provided in one embodiment of this application;

[0028] Figure 10 yes Figure 9 A schematic diagram of the assembly of the second permanent magnet, the magnetic conductor, and the rotor core;

[0029] Figure 11 This is a schematic diagram of the cross-sectional area of ​​the second permanent magnet gradually decreasing and exploding with that of the first permanent magnet in one embodiment of this application;

[0030] Figure 12 yes Figure 11 A schematic diagram of the assembly of the second permanent magnet, the magnetic conductor, and the rotor core;

[0031] Figure 13 This is a three-dimensional structural diagram of the first permanent magnet and the second permanent magnet provided in one embodiment of this application;

[0032] Figure 14 yes Figure 13 A schematic diagram of the assembly of the second permanent magnet with the magnetic conductor and the rotor core;

[0033] Figure 15 yes Figure 3 An exploded schematic diagram of an internal rotor stepper motor;

[0034] Figure 16 yes Figure 4 A three-dimensional structural diagram of the protective component.

[0035] The following are the labeling elements in the figure:

[0036] 100. Stepper motor; 101. Stator structure; 200. Rotating shaft; 301. Rotor core; 3011. Positioning hole; 3012. Rotor slot; 401. First permanent magnet; 402. Magnetic conductor; 403. Magnetic conductor; 4022. Second permanent magnet; 4023. Third permanent magnet; 4024. Fourth permanent magnet; 500. Snap ring; 501. Fixing base; 502. Positioning ring; 503. Guide surface; 603. Annular slot; 600. Injection molded insert; 601. Injection molded ring cover; 602. Injection molded rib; 102. Stator core; 800. Frame; 803. Wire groove; 900. Coil winding; Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the scope of this application.

[0038] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly or indirectly attached to that other component. When a component is referred to as "connected to" another component, it can be directly or indirectly connected to that other component. The terms "upper," "lower," "left," "right," etc., indicate orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, and are for ease of description only, not to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. "A plurality" means two or more, unless otherwise explicitly defined.

[0039] Please see Figures 1 to 10 This application provides a rotor structure and a stepper motor having the rotor structure, which can cooperate with the stator structure 101 to output torque.

[0040] Please see Figures 1 to 4The rotor structure includes: a rotating shaft 200, a first permanent magnet 401 in an annular shape that is fitted and connected to the rotating shaft 200, a magnetic conductor 402 connecting the first permanent magnet 401, and a rotor core 301 fitted over the rotating shaft 200. Two rotor cores 301 are arranged at intervals along the axial direction of the rotating shaft 200. The first permanent magnet 401 and the magnetic conductor 402 are located between the two rotor cores 301. Two magnetic conductors 402 are provided, located on opposite sides of the first permanent magnet 401 and corresponding to the two rotor cores 301. The magnetic conductor 402 has connecting holes that extend through both ends of the magnetic conductor 402 along the axial direction of the rotating shaft 200, allowing the magnetic conductor 402 to fit over the rotating shaft 200. It is understood that the first permanent magnet 401 can generate a constant magnetic field, which couples the rotor structure with the coil windings on the stator structure 101. The rotor core 301 has a positioning hole 3011, through which it is fitted onto the rotating shaft 200. A magnetic conductor 402 extends into the positioning hole 3011, such that the magnetic conductor 402 and the rotor core 301 overlap radially along the rotating shaft 200. The positioning hole 3011 extends axially through both ends of the rotor core 301 along the rotating shaft 200. One end of the magnetic conductor 402 is connected to the first permanent magnet 401, and the other end extends into the adjacent positioning hole 3011. This increases the strength and concentration of the magnetic field, reduces magnetic flux leakage, and thus improves the motor's torque output, efficiency, and performance.

[0041] It is understandable that the overlap between the magnetic conductor 402 and the rotor core 301 can be such that the magnetic conductor 402 is located inside the rotor core 301, or the rotor core 301 is located inside the magnetic conductor 402. This allows the magnetic conductor 402 to concentrate the magnetic flux generated by the first permanent magnet 401 at the rotor core 301, shortening the magnetic flux conduction path, reducing leakage flux, increasing the magnetic flux at the rotor core 301, and then strengthening the magnetic flux conduction path through the rotor core 301 to form a closed magnetic circuit. Ultimately, this can increase the magnetic field strength at the rotor core 301 and enhance the output power and torque of the rotor structure.

[0042] Please see Figures 1 to 4 The rotor structure provided in this application includes a rotating shaft 200, a first permanent magnet 401, a magnetic conductor 402, and a rotor core 301. By overlapping the rotor core 301 and the magnetic conductor 402 along the radial direction of the rotating shaft 200, the magnetic flux generated by the first permanent magnet 401 is concentrated at the rotor core 301, increasing the magnetic flux at the rotor core 301. Then, through the magnetic conduction of the rotor core 301, a closed magnetic circuit is formed, which ultimately increases the magnetic field strength at the rotor core 301 and enhances the output power and torque of the rotor structure.

[0043] Optionally, in this embodiment, the inner diameter hole of the rotor core 301 is fitted onto the magnetic conductor 402, so that the outer diameter of the magnetic conductor 402 overlaps with the radial surface of the inner diameter of the rotor core 301, and the inner diameter of the magnetic conductor 402 overlaps with the radial surface of the rotating shaft 200. This allows for more effective utilization of the magnetic field, providing a greater torque density. Under the same size and weight, the rotor structure can provide higher torque output, which is beneficial for the miniaturization and compactness of the stepper motor 100.

[0044] Please see Figures 1 to 4 Understandably, the first permanent magnet 401 is located between the two rotor cores 301. The rotor cores 301 fix the first permanent magnet 401 within them by clamping or fixing, improving the stability of the first permanent magnet 401 and also helping to ensure the stability and consistency of the magnetic field, enabling the magnetic flux to be effectively transmitted to the stator coil windings, thereby realizing the movement of the stepper motor 100. The rotor core 301 can be made of magnetically permeable material (such as silicon steel sheet) to improve the transmission efficiency of magnetic flux, and usually has a ring-shaped or columnar structure, forming a closed shape around both sides of the first permanent magnet 401.

[0045] Please see Figures 1 to 4 In some embodiments, the magnetic conductor 402 is made of pure iron and is completely located within the positioning hole 3011. The magnetic conductor 402 made of pure iron is cylindrical, and the connecting hole is located at the center of the magnetic conductor 402. The magnetic conductor 402 made of pure iron has the characteristics of high magnetic permeability and low hysteresis loss.

[0046] Please see Figure 5 In some embodiments, the rotor structure further includes a second permanent magnet 4022 sleeved on the rotating shaft 200, the outer diameter of the second permanent magnet 4022 being smaller than the outer diameter of the first permanent magnet 401; the magnetization direction of the first permanent magnet 401 is the same as the magnetization direction of the second permanent magnet 4022 and both are along the axial direction of the rotating shaft 200; the second permanent magnet 4022 is provided on both sides of the first permanent magnet 401, the two second permanent magnets 4022 are respectively located in the inner diameter holes of the two rotor cores 301, and the two second permanent magnets 4022 are respectively adjacent to the two magnetic conductors 402.

[0047] Please see Figure 6It is understandable that the magnetization direction can be to the left or to the right along the axis of rotation 200. Two second permanent magnets 4022 are respectively connected to both sides of the first permanent magnet 401. The two second permanent magnets 4022 can also generate a magnetic field, and since the magnetization directions of the first permanent magnet 401 and the two second permanent magnets 4022 are the same, the first permanent magnet 401 and the two second permanent magnets 4022 form a composite permanent magnet structure. The magnetic fields of the two second permanent magnets 4022 can be superimposed with the magnetic field of the first permanent magnet 401, enhancing the overall magnetic field strength and increasing the concentration of the magnetic field, which helps to improve the output torque and performance of the stepper motor 100.

[0048] Please see Figure 5 In some embodiments, the second permanent magnet 4022 is annular, and the outer diameter of the magnetic conductor 402 is smaller than the outer diameter of the first permanent magnet 401, and the sum of the thicknesses of the two second permanent magnets 4022 along the rotation axis 200 is greater than the thickness of the first permanent magnet 401 along the rotation axis 200.

[0049] Optionally, by making the outer diameter of the second permanent magnet 4022 smaller than the outer diameter of the first permanent magnet 401, and the sum of the thicknesses of the two second permanent magnets 4022 greater than that of the first permanent magnet 401, it is beneficial to miniaturize the overall size of the rotor structure.

[0050] Please see Figure 7 and Figure 8 In some embodiments, the cross-sectional area of ​​the second permanent magnet 4022 is gradually reduced along the direction away from the first permanent magnet 401, and the longitudinal cross-sectional shape of the second permanent magnet 4022 is trapezoidal. The two second permanent magnets 4022 are respectively located at the inner ring holes of the two magnetic conductors 402.

[0051] By extending the second permanent magnet 4022 to the inner ring hole of the magnetic conductor 402, more areas of the magnetic conductor 402 are exposed to the magnetic field, allowing the magnetic field to act more uniformly on the magnetic conductor 402 and to have a wider impact on the rotor core 301. This increases the range of the magnetic field and enhances the interaction between the magnetic field and the rotor core 301, thereby increasing the output torque of the stepper motor 100.

[0052] It is also understandable that the second permanent magnet 4022 extends into the magnetic conductor 402, forming a more direct magnetic field conduction path, which can reduce magnetic field leakage and diffusion, improve the magnetic field conduction efficiency, and make the magnetic field act more concentrated on the rotor core 301, thereby enhancing the torque output of the stepper motor 100.

[0053] Please see Figure 7 and Figure 8It is understandable that the longitudinal cross-section of the second permanent magnet 4022 is trapezoidal, and the large end of the second permanent magnet 4022 is connected to the first permanent magnet 401, so that the second permanent magnet 4022 and the first permanent magnet 401 have a closer and larger contact area. This allows more magnetic flux from the first permanent magnet 401 to be concentrated in the second permanent magnet 4022. Furthermore, the small end of the second permanent magnet 4022 extends into the inner ring hole of the magnetic conductor 402, forming a more direct magnetic field conduction path. This makes the magnetic field more concentrated in the central region of the rotor core 301, which can increase the range of action of the magnetic field, reduce magnetic leakage and diffusion, improve the conduction efficiency of the magnetic field, and thus increase the output torque of the stepper motor 100.

[0054] Please see Figure 7 and Figure 8 It is understandable that the shape of the inner ring hole of the magnetic conductor 402 is adapted to the shape of the second permanent magnet 4022, and the longitudinal cross-sectional shape of the inner ring hole of the magnetic conductor 402 is also trapezoidal.

[0055] Please see Figure 9 and Figure 10 The rotor structure further includes a third permanent magnet 4023. The magnetization direction of the first permanent magnet 401 is the same as that of the third permanent magnet 4023 and both are along the axial direction of the rotating shaft 200. The first permanent magnet 401 has an inner annular hole, and the inner diameter of the first permanent magnet 401 is fitted onto the outer diameter of the third permanent magnet 4023. The two ends of the third permanent magnet (4023) are respectively adjacent to the two magnetic conductors (402).

[0056] Please see Figure 9 and Figure 10 It is understandable that the magnetization direction can be to the left or to the right along the axial direction of the rotation axis 200. The third permanent magnet 4023 is ring-shaped, and its two ends extend toward the two magnetic conductors 402 respectively. The third permanent magnet 4023 can also generate a magnetic field. Since the magnetization directions of the first permanent magnet 401 and the third permanent magnet 4023 are the same, the first permanent magnet 401 and the third permanent magnet 4023 form a composite permanent magnet structure. The magnetic field of the third permanent magnet 4023 can be superimposed with the magnetic field of the first permanent magnet 401, enhancing the overall magnetic field strength and increasing the concentration of the magnetic field, which helps to improve the output torque and performance of the stepper motor 100.

[0057] Please see Figure 11 and Figure 12 In some embodiments, the two ends of the third permanent magnet 4023 are respectively located at the inner ring holes of the two magnetic conductors 402. The cross-sectional area of ​​any end of the third permanent magnet 4023 gradually increases along the direction pointing to the first permanent magnet 401, and its longitudinal section is trapezoidal.

[0058] Please see Figure 11 and Figure 12 It is understandable that the two ends of the third permanent magnet 4023 extend into the inner ring holes of the two magnetic conductors 402, forming a more direct magnetic field conduction path. This exposes more areas of the magnetic conductors 402 to the magnetic field, reducing magnetic leakage and diffusion, improving the magnetic field conduction efficiency, and continuously concentrating the magnetic flux at both ends of the third permanent magnet 4023. This makes the magnetic field act more concentrated on the rotor core 301 and the magnetic conductors 402, thereby enhancing the torque output of the stepper motor 100.

[0059] Please see Figure 13 and Figure 14 In some embodiments, the rotor structure further includes a ring-shaped fourth permanent magnet 4024. The rotating shaft 200 is located inside the fourth permanent magnet 4024, and the fourth permanent magnet 4024 is concentric with the rotating shaft 200. The fourth permanent magnet 4024 is sleeved on the rotating shaft 200. The fourth permanent magnet 4024 is provided on both sides of the first permanent magnet 401, and the two fourth permanent magnets 4024 are respectively located in the inner diameter holes of the two magnetic conductors 402. The magnetization direction of one of the fourth permanent magnets 4024 is radially outward along the rotating shaft 200, as shown in the figure. As shown by arrow F1 on the right side of body 401; the magnetization direction of the other fourth permanent magnet 4024 is radial and inward along the rotation axis 200, as shown by arrow F3 on the left side of the first permanent magnet 401; the first permanent magnet 401 is magnetized along the axial direction of the rotation axis 200, as shown by arrow F2, and the magnetization direction of the first permanent magnet 401 points from the inwardly magnetized fourth permanent magnet 4024 to the outwardly magnetized fourth permanent magnet 4024, so that the overall magnetization direction is set clockwise. In other embodiments, the overall magnetization direction can also be set counterclockwise. There is no limitation here, and it can be selected according to the actual situation.

[0060] Please see Figure 13 and Figure 14 Understandably, the first permanent magnet 401 generates an axial magnetic field, with magnetic field lines flowing from one extreme to the other. One of the fourth permanent magnets 4024 is magnetized radially outward, generating an outward radial magnetic field with magnetic field lines distributed in a ring shape; the other fourth permanent magnet 4024 generates an inward radial magnetic field, with magnetic field lines also distributed in a ring shape. By placing the two fourth permanent magnets 4024 on opposite sides of the first permanent magnet 401, a composite permanent magnet is formed. The combination of axial and radial magnetization provides a stronger magnetic field effect, enhancing the strength and distribution of the magnetic field, and increasing the output torque of the motor.

[0061] Please see Figure 13 and Figure 14In some embodiments, the rotor structure further includes a cylindrical magnetic conductor 403 fitted with a rotating shaft 200. The magnetic conductor 403 passes through the inner annular hole of the first permanent magnet 401, and its two ends pass through the inner annular holes of two fourth permanent magnets 4024, respectively. The magnetic conductor 403 is made of pure iron.

[0062] Understandably, the magnetic conductor 403, made of pure iron, can enhance magnetic circuit conduction. Pure iron has good magnetic permeability and can provide lower magnetic resistance, thereby enhancing the magnetic field conduction capability. Through the magnetic conductor 403 located between the two fourth permanent magnets 4024 and penetrating the first permanent magnet 401, a more complete magnetic circuit can be formed, reducing magnetic leakage and improving magnetic field transmission efficiency.

[0063] The magnetic conductor 403 can also increase the magnetic field strength. The presence of the magnetic conductor 403 can increase the magnetic field strength, making the magnetic field between the two fourth permanent magnets 4024 more uniform and concentrated, which helps to improve the output torque and performance of the stepper motor 100.

[0064] The magnetic conductor 403 can also increase magnetic field coupling, so that the magnetic conductor 403, the first permanent magnet 401 and the two fourth permanent magnets 4024 form a tighter magnetic field coupling, which can increase the mutual magnetic field influence and improve the responsiveness and control performance of the stepper motor 100.

[0065] In some embodiments, a plurality of rotor slots 3012 are formed on the side surface of the rotor core 301 along the axial direction of the rotation shaft 200, and the rotor slots 3012 are arranged at intervals along the circumference of the rotor core 301; wherein the rotor slots 3012 on one rotor core 301 are staggered relative to the rotor slots 3012 on another rotor core 301 along the circumference of the rotation shaft 200.

[0066] The present invention also proposes a stepper motor, which includes the rotor structure shown in the above embodiments. The specific structure of the rotor structure is as described in the above embodiments. Since the stepper motor adopts all the technical solutions of all the above embodiments, it also has all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0067] Please see Figures 1 to 4 In some embodiments, the stepper motor further includes a stator structure 101 and a rotor structure located inside the positioning structure, thus the stepper motor provided in this embodiment is an internal rotor stepper motor 100.

[0068] Please see Figure 3 , Figure 4 and Figure 15The stator structure 101 includes: a stator core 102 fitted over the rotor core 301; a frame 800 connected to the stator core 102 and having slots 803; a coil winding 900 located within the slots 803; a protective member 805 surrounding the coil winding 900 and at least partially located within the slots 803; and an injection-molded insert 600 molded onto the protective member 805. Both opposite end faces of the frame 800 are covered with the injection-molded insert 600. The stator core 102 provides a stable magnetic field and mechanical support, ensuring the normal operation of the stepper motor. The frame 800 is embedded within the stator core 102 and allows the coil winding 900 to be effectively mounted in the slots 803, ensuring correct current flow through the coil winding 900 and improving the efficiency and performance of the stepper motor. The coil winding 900 generates a magnetic field when charged.

[0069] Please see Figure 3 , Figure 4 and Figure 15 The protective component 805 is wrapped around the outer periphery of the coil winding 900. During the injection molding process of the injection insert 600, the protective component 805 can isolate the high-temperature injection molding material from the coil winding 900, allowing the coil winding 900 to resist the high temperature of the injection molding material and the impact force of the flow of the injection molding material through the protective component 805. This prevents the enameled wire of the coil winding 900 from being damaged, thus improving the reliability of the coil winding 900.

[0070] Optionally, the stator core 102 has a rotating cavity for mounting the rotor structure, and the outer peripheral surface of the coil winding 900 can be the surface of the coil winding 900 along the circumference of the rotating cavity.

[0071] Please see Figure 3 , Figure 4 and Figure 15 Multiple slots 803 are arranged at equal intervals along the circumference of the rotating cavity, and each slot 803 contains a coil winding 900. A protective member 805 is wrapped around the outer periphery of the coil winding 900, so that when the injection-molded insert 600 is injection molded, the protective member 805 can resist the high temperature of the injection molding process, preventing damage to the enameled wire of the coil winding 900 and thus the coil winding 900.

[0072] Please see Figure 3 , Figure 4 and Figure 15 Optionally, the frame 800 includes an upper frame 801 made of insulating material and a lower frame 802, also made of insulating material, which is stacked and mated with the upper frame 801. The two ends of the wire groove 803 extend to the upper frame 801 and the lower frame 802, respectively. The two ends of the coil winding 900 extend to the upper frame 801 and the lower frame 802, respectively, and protective members 805 are provided inside both the upper frame 801 and the lower frame 802.

[0073] In some embodiments, the protective element is made of a flexible thin film material and is wrapped around the outer periphery of the coil winding 900.

[0074] Please see Figure 3 , Figure 4 and Figure 15 Optionally, the flexible film material can be a plastic film. The plastic film repeatedly inserts and exits through each wire groove 803 and covers the corresponding coil winding 900. Other methods can also be used to cover the coil winding 900; there are no restrictions here, and the appropriate method can be chosen based on the actual situation. During the injection molding process of the injection insert 600, the flexible film's protective function allows the coil winding 900 to resist the high temperature of the injection molding process and the impact force of the injection molding material. After injection molding, the injection insert 600 seals and fixes the coil winding 900.

[0075] In some embodiments, the protective member 805 is made of a rigid material and has a protective groove, the coil winding 900 is located in the protective groove, and the protective member 805 is provided at both ends of the groove 803.

[0076] Please see Figure 16 Optionally, the protective component 805 includes a top plate and two side plates 8052 spaced apart on the top plate 8051. The side plates 8052 and the top plate 8051 together form a protective groove 8053. By inserting the side plates 8052 into the wire groove 803, the coil winding 900 is at least partially positioned in the protective groove 8053, and the top plate 8051 is located at the end face of the frame 800. The rigid material can be rigid plastic, which allows the top plate 8051 and the side plates 8052 to be integrally formed. The protective component 805 is then partially inserted into the wire groove 803, thereby resisting the high temperature of the injection-molded insert 600 during the injection molding process and the impact force of the injection molding material.

[0077] Please see Figure 3 , Figure 4 and Figure 15 It is understandable that protective components 805 are inserted into the wire groove 803 of the upper frame 801 and the wire groove 803 of the lower frame 802, and the two side plates of the two protective components 805 are respectively connected, and the two top plates are respectively located at the end face of the stator core 102, thereby realizing the enclosure and protection of the circumferential surface of the coil winding 900.

[0078] It is understandable that the protective component 805, made of rigid material, can be inserted into the wire groove 803 and the two side plates are appropriately interference-fitted with the inner wall of the wire groove 803. Thus, during the assembly of the stator structure 101, the protective component 805 can move together with the stator core 102, so that the coil winding 900 will not move unexpectedly relative to the frame 800.

[0079] Please see Figure 3 , Figure 4 and Figure 15 In some embodiments, the wire groove 803 has a slot located at the end face of the stator core 102, and both ends of the stator core 102 have slots. The edge of the slot is provided with a limiting boss, and at least two limiting bosses are provided at intervals.

[0080] Optionally, two concentric rings of limiting protrusions 804 are arranged radially around the skeleton 800, and multiple limiting protrusions 804 are arranged circumferentially around the skeleton 800 in each ring, so that limiting protrusions 804 are arranged at the edge of the slot of each wire groove 803. Before injection molding, the limiting protrusions 804 can shape the coil winding 900 at the end of the injection-molded insert 600, and the height of the protective part 805 exposed outside the wire groove 803 is consistent with the height of the shaping mold. By setting the limiting protrusions 804, the safety of the installation of the protective part 805 can be improved. During the process of pressing the protective part 805 into the wire groove 803, the limiting protrusions 804 can prevent the protective part 805 from being over-pressed in, thereby preventing the top plate from over-compressing the coil winding 900.

[0081] Please see Figure 3 , Figure 4 and Figure 15 In some embodiments, the injection-molded insert 600 includes two injection-molded ring caps 601 and injection-molded ribs 602. The two injection-molded ring caps 601 respectively cover the end faces of both ends of the skeleton 800 and are plastically connected to the protective member 805. The injection-molded ribs 602 pass through the wire grooves 803, and the two ends of the injection-molded ribs 602 are respectively connected to the two injection-molded ring caps 601.

[0082] Optionally, each wire groove 803 has a molded rib 602 formed inside it, and side plates are provided on both sides of the molded rib 602. The reliability of the connection between the two molded ring caps 601 can be improved by multiple molded ribs 602.

[0083] Please see Figure 3 , Figure 4 and Figure 15 Optionally, the inner wall of the rotating cavity is provided with multiple grooves between any two adjacent grooves 803. During the injection molding process of the injection insert 600, baffles can be set at both ends of the grooves to prevent the injection molding material from flowing into the grooves. This can prevent the generation of injection molding powder in the grooves when the inner wall of the rotating cavity is polished later, and improve the convenience of assembly and processing of the stator structure 101.

[0084] In some embodiments, a heat dissipation groove 504 is formed on the outer surface of the injection-molded ring cover 601. The extension path of the heat dissipation groove 504 is arranged in a ring shape. By forming the heat dissipation groove 504, the heat dissipation area of ​​the injection-molded ring cover 601 can be increased, the temperature of the motor can be reduced, and thus the stability of motor operation can be improved. Multiple heat dissipation grooves 504 are arranged at intervals.

[0085] Please see Figures 1 to 4 In some embodiments, the stator structure 101 further includes a fixing ring 107 that is sleeved on one of the injection-molded ring caps 601 and a connecting lug 108 disposed on the fixing ring 107 and having a connecting hole 106. Two connecting lugs 108 are arranged at intervals, and the two connecting lugs 108 are symmetrically arranged about the central axis of the rotating cavity.

[0086] It is understandable that the stator structure 101 is fixed to other structural components by means of two connecting lugs 108, i.e., bolts pass through the connecting holes 106, thereby achieving a detachable connection between the connecting lugs 108 and other structural components.

[0087] Please see Figures 1 to 4 In some embodiments, the retaining ring 107, the connecting lug 108, and the corresponding injection-molded ring cap 601 are integrally injection molded. It is understood that the retaining ring 107, the connecting lug 108, and the injection-molded ring cap 601 are all integrally formed from injection molding material and through an injection molding process, which not only improves the ease of assembly of the stator structure 101 but also reduces the cost of the stator structure 101. A reinforcing sleeve 104 is provided inside the connecting hole 106. The reinforcing sleeve 104 is made of a metal material, such as stainless steel. By providing the reinforcing sleeve 104, the wear resistance and structural strength of the connecting hole 106 can be improved.

[0088] Please see Figures 1 to 4 In some embodiments, the fixing ring 107 and the connecting lug 108 are integrally formed, the inner wall of the fixing ring 107 is provided with a positioning notch, and the injection-molded ring cap 601 is filled with a filling part 105 into the positioning notch.

[0089] Please see Figures 1 to 4 Optionally, both the retaining ring 107 and the connecting lug 108 are made of metal, such as aluminum alloy. The retaining ring 107 has two positioning notches spaced apart near the inner wall of either connecting lug 108. During injection molding, the plastic material fills the two positioning notches of the injection-molded ring cap 601, forming a filling portion 105 that connects the injection-molded ring cap 601 and the retaining ring 107, thus improving the reliability of the connection between the retaining ring 107 and the injection-molded ring cap 601.

[0090] Please see Figure 3 , Figure 4 and Figure 15 In some embodiments, the injection-molded ring cap 601 has a mounting hole, and the wall of the mounting hole has an annular groove 603. The stator structure 101 also includes a fixing seat 501 for fixing the rotating shaft 200 and located in the mounting hole. The peripheral side of the fixing seat 501 is provided with a positioning ring 502 that is adapted to the annular groove 603. The positioning ring 502 has a guide surface 503 for guiding the positioning ring 502 into the annular groove 603.

[0091] Please see Figure 3 , Figure 4 and Figure 15 It is understandable that the guide surface 503 improves the ease of assembly of the fixing seat 501 and the injection ring cover 601, and prevents the injection ring cover 601 from being excessively squeezed and breaking. A fixing seat 501 is provided at each of the two injection ring covers 601. The fixing seat 501 can be made of metal, such as aluminum alloy. Both the fixing seat 501 and the injection ring cover 601 are detachably connected via a positioning ring 502 and an annular groove 603. The fixing seat 501 has bearing holes for fixing bearings, and each bearing hole contains a bearing. Two bearings are connected to both ends of the rotating shaft 200 of the rotor structure.

[0092] It is understandable that the fixing seat 501 can also be made of plastic material, and the ring cover 601 can be integrally molded by injection molding process. In order to enhance the reliability of the connection between the fixing seat 501 and the bearing, a metal sleeve can be inserted into the bearing hole, and then the bearing can be placed in the metal sleeve.

[0093] Optionally, the injection-molded ring cap 601 is also provided with a retaining ring 500 to strengthen the connection between the injection-molded ring cap 601 and the fixing seat 501.

[0094] The above are merely optional embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A rotor structure, characterized in that, include: The system comprises a rotating shaft (200), a first permanent magnet (401) in an annular shape and connected to the rotating shaft (200), a magnetic conductor (402) connected to the first permanent magnet (401), and a rotor core (301) surrounding the magnetic conductor (402). Two rotor cores (301) are arranged at intervals. The first permanent magnet (401) is located between the two rotor cores (301). Two magnetic conductors (402) are provided, located on both sides of the first permanent magnet (401) and corresponding to the two rotor cores (301). The magnetic conductors (402) overlap with the adjacent rotor cores (301) along the radial surface of the rotating shaft (200). The inner diameter hole of the rotor core (301) is fitted onto the magnetic conductor (402) so that the outer diameter of the magnetic conductor (402) overlaps with the radial surface of the inner diameter of the rotor core (301), and the inner diameter of the magnetic conductor (402) overlaps with the radial surface of the rotating shaft (200). The rotor structure further includes a second permanent magnet (4022) sleeved on the rotating shaft (200), the outer diameter of the second permanent magnet (4022) being smaller than the outer diameter of the first permanent magnet (401); the magnetization direction of the first permanent magnet (401) is the same as the magnetization direction of the second permanent magnet (4022) and both are along the axial direction of the rotating shaft (200); a second permanent magnet (4022) is provided between each of the magnetic conductors (402) and the first permanent magnet (401), and the two second permanent magnets (4022) are respectively located in the inner diameter holes of the two rotor cores (301).

2. The rotor structure as described in claim 1, characterized in that: The cross-sectional area of ​​the second permanent magnet (4022) gradually decreases in the direction away from the first permanent magnet (401), and the longitudinal cross-sectional shape of the second permanent magnet (4022) is trapezoidal. The two second permanent magnets (4022) are respectively located at the inner ring holes of the two magnetic conductors (402).

3. The rotor structure as described in claim 1, characterized in that: The rotor structure further includes a third permanent magnet (4023), the magnetization direction of the first permanent magnet (401) is the same as that of the third permanent magnet (4023) and both are along the axial direction of the rotating shaft (200); the first permanent magnet (401) has an inner annular hole, the outer diameter of the third permanent magnet (4023) is smaller than the inner diameter of the first permanent magnet (401), and the inner diameter of the first permanent magnet (401) is fitted onto the outer diameter of the third permanent magnet (4023), and the two ends of the third permanent magnet (4023) are respectively adjacent to two magnetic conductors (402).

4. The rotor structure as described in claim 3, characterized in that: The two ends of the third permanent magnet (4023) are respectively located at the inner ring holes of the two magnetic conductors (402); the cross-sectional area of ​​any end of the third permanent magnet (4023) gradually increases along the direction pointing to the first permanent magnet (401), and its longitudinal section is trapezoidal.

5. The rotor structure as described in claim 1, characterized in that: The rotor structure further includes a ring-shaped fourth permanent magnet (4024). The rotating shaft (200) is located inside the fourth permanent magnet (4024), and the fourth permanent magnet (4024) is concentric with the rotating shaft (200). The fourth permanent magnet (4024) is provided on both sides of the first permanent magnet (401), and the two fourth permanent magnets (4024) are respectively located in the inner diameter holes of the two magnetic conductors (402). The fourth permanent magnet on one side... The magnetization direction of the first permanent magnet (4024) is radial and outward along the rotation axis (200), and the magnetization direction of the fourth permanent magnet (4024) on the other side is radial and inward along the rotation axis (200); the first permanent magnet (401) is magnetized along the axial direction of the rotation axis (200), and the magnetization direction of the first permanent magnet (401) is along the direction of the inwardly magnetized fourth permanent magnet (4024) pointing to the direction of the outwardly magnetized fourth permanent magnet (4024).

6. The rotor structure as described in claim 5, characterized in that: The rotor structure also includes a cylindrical magnetic guide (403) that is fitted over the rotating shaft (200). The magnetic guide (403) passes through the inner ring hole of the first permanent magnet (401), and the two ends of the magnetic guide (403) pass through the inner ring holes of the two fourth permanent magnets (4024).

7. A stepper motor (100), characterized in that: Including the rotor structure as described in any one of claims 1-6, the stepper motor (100) further includes a stator structure (101) that cooperates with the rotor structure. The stator structure (101) includes: a stator core (102) sleeved on the rotor core (301), a frame (800) connected to the stator core (102) and having a slot (803), a coil winding (900) located in the slot (803), a protective member surrounding the outer periphery of the coil winding (900) and at least partially located in the slot (803), and an injection-molded insert (600) molded on the protective member. The two opposite end faces of the frame (800) are covered by the injection-molded insert (600).

8. The stepper motor (100) as described in claim 7, characterized in that: The protective element is made of a flexible thin film material and is wrapped around the outer periphery of the coil winding (900); or the protective element is made of a rigid material and has a protective groove, the coil winding (900) is located in the protective groove, and the protective element is provided at both ends of the groove (803).

Images