Motor and electric toothbrush with same
By setting protruding parts and installation grooves on the end cover of the motor, combined with the design of grooves and elastic parts, the problems of excessive motor size and inconvenient installation are solved, and the power output and installation accuracy are improved. It is suitable for small space applications such as electric toothbrushes. .
Patent Information
- Application Number
- CN202323409175.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-13
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2033-12-13
AI Technical Summary
When used in electric toothbrushes, the motor size increases due to the long axial size of the tail cover, which in turn affects the output performance and is inconvenient to install.
By providing protrusions and installation grooves on the end cover of the motor, the bearing is installed in the grooves, and the shaft passes through the grooves at the bottom of the grooves, using the limiting effect of the grooves to improve assembly accuracy, and absorb errors through the elastic parts to reduce The axial dimensions of the motor enhance power output.
It realizes the motor's output power, high installation accuracy and easy installation, and is suitable for applications in narrow spaces, while reducing production costs.
Smart Images
Figure CN222147288U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of motor equipment, and in particular to a motor and an electric toothbrush having the same. Background Art
[0002] The motor in the related art usually includes a stator assembly and a rotor assembly. The rotor assembly is located in the stator assembly and is rotatable relative to the stator assembly. The stator assembly is equipped with a tail cover, which extends along the axial direction of the motor. The tail cover is used for installation and positioning with the motor. For example, when the motor is used in an electric toothbrush, the tail cover is connected to the mounting bracket in the electric toothbrush. Therefore, the tail cover is arranged longer in the axial direction of the motor, resulting in the axial dimension of the motor becoming longer. In order to reduce the size of the motor, it is necessary to shorten the magnet of the stator assembly and the rotor assembly, which affects the output performance of the motor and affects the power output of the motor. Utility Model Content
[0003] The purpose of the present application is to provide a motor having the advantages of large output power, high installation precision and convenient installation.
[0004] In order to achieve the above-mentioned purpose, a first aspect embodiment of the present application provides a motor, including a stator assembly, an end cover, a bearing and a rotor assembly, wherein the stator assembly includes a stator shell, and an opening is provided at the end of the stator shell; the end cover is connected to the stator shell and is used to cover the opening, the end cover includes a protrusion, and in the axial direction of the motor, the protrusion exceeds the outer surface of the rest of the end cover, the inner surface of the protrusion is provided with a mounting groove, and the groove bottom of the mounting groove is provided with a groove, and the cross-sectional area of the groove is smaller than the cross-sectional area of the mounting groove; the bearing is provided in the mounting groove, and in the axial direction of the motor, the bearing is located outside the stator shell; the rotor assembly is provided in the stator shell and is rotatable relative to the stator assembly; the rotating shaft is passed through the bearing and the rotor assembly, and the rotor assembly drives the rotating shaft to rotate relative to the stator assembly, and a part of the rotating shaft is located in the groove.
[0005] In some embodiments of the present application, in the axial direction of the motor, the dimension of the protrusion exceeding the outer surface of the rest of the end cover is H1, the dimension of the bearing is H2, and the ratio of H1 to H2 is not greater than 3.
[0006] In some embodiments of the present application, in the axial direction of the motor, the dimension of the protrusion exceeding the outer surface of the rest of the end cover is H1, and H1 is not greater than 3 mm and not greater than 7 mm.
[0007] In some embodiments of the present application, in the axial direction of the motor, the inner surface of the protrusion is flush with the end surface of the stator shell, or the inner surface of the protrusion is spaced apart from the stator shell.
[0008] In some embodiments of the present application, the distance between the protrusion and the outer edge of the end cover is not less than 2 mm.
[0009] In some embodiments of the present application, in the axial direction of the motor, the inner side edge of the groove side wall of the mounting groove is flush with the inner side surface of the bearing, or the inner side edge of the groove side wall of the mounting groove protrudes inward relative to the inner side surface of the bearing.
[0010] In some embodiments of the present application, the motor satisfies at least one of the following: in the axial direction of the motor, the dimension of the rotating shaft extending beyond the outer side surface of the bearing is not greater than 2 mm; in the axial direction of the motor, the distance between the bearing and the bottom wall of the groove is not greater than 2 mm; in the axial direction of the motor, the distance between the outer surface of the protrusion and the bottom wall of the groove is not greater than 2 mm.
[0011] In some embodiments of the present application, the motor further includes: an elastic member, which is located between the bearing and the bottom wall of the mounting groove and can be elastically deformed; wherein, in the axial direction of the motor, the size of the bearing is H2, the size of the elastic member in a natural state is H3, the depth of the mounting groove is H4, and the sum of H2 and H3 is less than H4.
[0012] In some embodiments of the present application, the end cover is provided with a wire passing hole, and the wire passing hole passes through the end cover along the axial direction of the motor; in the radial direction of the motor, the wire passing hole is located between the edge of the end cover and the protrusion, and the distance between the wire passing hole and the protrusion is not greater than 2 mm.
[0013] In some embodiments of the present application, the motor has a first radial direction and a second radial direction, the first radial direction and the second radial direction are perpendicular to each other, and the spacing between the inner surfaces of the stator shell on both sides in the first radial direction is greater than the spacing between the inner surfaces of the stator shell on both sides in the second radial direction; the rotor assembly also includes a rotor core and two coils, the rotating shaft is passed through the rotor core, is sleeved on the rotating shaft and is transmission-connected to the rotating shaft, and the two coils are arranged on opposite sides of the rotor core in the first radial direction; wherein the wire passing hole is arranged between the edge of the end cover in the second radial direction and the protrusion, and the wire passing hole is located in the central area of the motor in the first radial direction.
[0014] In some embodiments of the present application, in the first radial direction, the size of the wire hole is not less than 0.8 mm and not more than 1.8 mm.
[0015] In some embodiments of the present application, the motor further includes a limit member and an anti-wear member, wherein the limit member is sleeved on the rotating shaft, and the limit member stops at the side of the bearing facing away from the end cover; the anti-wear member is sleeved on the rotating shaft, and the anti-wear member is located on the side of the limit member facing away from the bearing; wherein, in the radial direction of the motor, the outer edge of the anti-wear member is located between the outer edge of the limit member and the inner wall of the wire hole.
[0016] In some embodiments of the present application, the end cover also includes a connecting portion and an inserting portion, the connecting portion is connected to the protruding portion and extends along the circumference of the protruding portion, and the connecting portion stops at the end surface of the stator shell; the inserting portion is connected to the inner side surface of the connecting portion and is inserted into the stator shell; wherein a guide structure is provided at one end of the inserting portion facing away from the connecting portion, and in the axial direction of the motor, the outer circumferential surface of the guide structure gradually approaches the rotating shaft from the outside to the inside.
[0017] In some embodiments of the present application, the stator assembly also includes a yoke and a permanent magnet, the yoke is arranged between the stator shell and the rotor assembly; the permanent magnet is arranged on the inner circumferential surface of the yoke; wherein, in the axial direction of the motor, the spacing between the insertion portion and the yoke is not less than 0.5 mm and not more than 3 mm.
[0018] A second aspect embodiment of the present application provides an electric toothbrush, comprising a handle shell and a movement, wherein the movement comprises the motor according to the first aspect embodiment of the present application, and the movement is disposed in the handle shell.
[0019] In some embodiments of the present application, the movement also includes a circuit board and a mounting bracket, and the circuit board is connected to the motor; in the radial direction of the electric toothbrush, the circuit board and the motor are arranged on opposite sides of the mounting bracket, and the mounting bracket clamps the axial ends of the motor; wherein the end cover is provided with a wire passing hole, and the wire passing hole is located between the protrusion and the mounting bracket.
[0020] In some embodiments of the present application, the mounting bracket includes a first frame and a second frame, the first frame and the second frame are detachably connected, and the first frame and the second frame are arranged along the radial direction of the motor.
[0021] The motor of the embodiment of the present application, by installing the bearing into the installation groove of the end cover, the bearing will not occupy the space in the stator shell, and there is no need to increase the size of the stator shell in the axial direction of the motor, and there is more space to arrange the rotor assembly and the remaining components of the stator assembly, thereby increasing the force between the stator assembly and the rotor assembly, and thus increasing the power output of the motor. The bottom of the installation groove is provided with a groove, and the shaft extends into the groove. The groove is used to accommodate a part of the shaft, and the cross-sectional area of the groove is smaller than the cross-sectional area of the installation groove. On the one hand, the bottom wall of the installation groove can stop the bearing to prevent the bearing from being installed in the groove, which can play a role in indicating that the installation is in place, and the installation is more convenient. On the other hand, the inner circumference of the groove can limit the shaft, further improving the assembly accuracy. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.
[0023] Figure 1 A schematic diagram of the structure of a motor according to an embodiment of the present application;
[0024] Figure 2 A schematic structural diagram of a motor from another perspective of an embodiment of the present application;
[0025] Figure 3 An exploded diagram of a motor according to an embodiment of the present application;
[0026] Figure 4 This is one of the cross-sectional views of the motor according to an embodiment of the present application;
[0027] Figure 5 A partial cross-sectional view of a motor according to an embodiment of the present application;
[0028] Figure 6 This is one of the structural schematic diagrams of the end cover of the motor according to an embodiment of the present application;
[0029] Figure 7 This is a second structural schematic diagram of the end cover of the motor according to an embodiment of the present application;
[0030] Figure 8 This is a third structural schematic diagram of the end cover of the motor according to an embodiment of the present application;
[0031] Fig. 9 This is a fourth structural schematic diagram of the end cover of the motor according to an embodiment of the present application;
[0032] Fig.10A schematic diagram of the connection between the rotor assembly, the rotating shaft, the stopper, the anti-wear member and the bearing of the motor according to an embodiment of the present application;
[0033] Fig.11 This is the second cross-sectional view of the motor according to the embodiment of the present application;
[0034] Fig.12 This is a schematic diagram of the matching of the end cover and the anti-wear part of the motor in an embodiment of the present application;
[0035] Fig.13 A schematic diagram of the coordination of the position-limiting member and the anti-wear member of the motor in an embodiment of the present application;
[0036] Fig.14 A schematic diagram of the structure of an electric toothbrush according to an embodiment of the present application;
[0037] Fig.15 This is a schematic diagram of the structure of the movement of the electric toothbrush according to an embodiment of the present application.
[0038] Description of Figure Numbers:
[0039] Motor 1, electric toothbrush 2, handle shell 3,
[0040] The rotor assembly 100, the coil 110, the rotor core 120,
[0041] stator assembly 200, yoke 210, permanent magnet 220, stator housing 250, opening 251,
[0042] Rotating shaft 300, bearing 400,
[0043] The end cover 500, the wire hole 501, the protrusion 510, the mounting groove 511, the groove side wall 512, the groove 513, the connecting portion 520, the inserting portion 530, the guide section 540, the guide structure 550,
[0044] Elastic member 600, limiting member 700, anti-wear member 800,
[0045] The movement 900 , the circuit board 910 , the mounting bracket 920 , the first frame 921 , and the second frame 922 .
[0046] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION
[0047] In order to make the objectives, technical solutions and advantages of the present application clearer, the following part will further describe the embodiments of the present application in detail in conjunction with the accompanying drawings.
[0048] When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are only examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims.
[0049] In the description of the present application, it should be understood that the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances. In addition, in the description of the present application, unless otherwise specified, "multiple" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects associated before and after are in an "or" relationship.
[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.
[0051] like Figure 14-15 As shown, the electric toothbrush 2 of the embodiment of the present application includes a brush head, a handle shell 3 and a movement 900. The movement 900 includes a motor 1 according to the following text of the present application, and the movement 900 is arranged in the handle shell 3. Among them, the handle shell 3 is used to be held by the user, and the brush head is connected to the rotating shaft 300 of the motor 1. The rotating shaft 300 drives the brush head to move to clean the user's oral cavity.
[0052] The motor 1 according to an embodiment of the present application is described below with reference to the accompanying drawings.
[0053] like Figure 1-Figure 5 As shown, the motor 1 of the embodiment of the present application includes a rotor assembly 100, an end cover 500, a bearing 400 and a stator assembly 200. The motor 1 may be a sonic motor 1.
[0054] The stator assembly 200 includes a stator shell 250, an opening 251 is provided at the end of the stator shell 250, an end cover 500 is connected to the stator shell 250, and the end cover 500 is used to cover the opening 251. The end cover 500 includes a protrusion 510. In the axial direction of the motor 1, the protrusion 510 exceeds the outer surface of the remaining part of the end cover 500. The inner surface of the protrusion 510 is provided with a mounting groove 511, and the bottom of the mounting groove 511 is provided with a groove 513, and the cross-sectional area of the groove 513 is smaller than the cross-sectional area of the mounting groove 511. The bearing 400 is provided in the mounting groove 511, and in the axial direction of the motor 1, the bearing 400 is located outside the stator shell 250.
[0055] The rotor assembly 100 is disposed in the stator housing 250. The rotor assembly 100 is rotatable relative to the stator assembly 200. The rotor assembly 100 can be installed in the stator housing 250 through the opening 251, or can be taken out of the stator housing 250 through the opening 251. The rotating shaft 300 is passed through the bearing 400 and the rotor assembly 100. The rotor assembly 100 drives the rotating shaft 300 to rotate relative to the stator assembly 200. A portion of the rotating shaft 300 is located in the groove 513. The rotating shaft 300 can be connected to the brush head of the electric toothbrush 2 to drive the electric toothbrush 2 to clean the oral cavity.
[0056] According to the motor 1 of the embodiment of the present application, by installing the bearing 400 into the installation groove 511 of the end cover 500, the relative positions of the bearing 400, the stator housing 250, the rotating shaft 300 and the rotor assembly 100 can be fixed, and the bearing 400 is located in the stator housing 250 in the axial direction of the motor 1, that is, the bearing 400 does not occupy the space in the stator housing 100, and there is no need to increase the axial size of the stator housing 250 in the motor 1, and there is more space to arrange the rotor assembly 100 and the remaining components of the stator assembly 200, thereby increasing the force between the stator assembly 200 and the rotor assembly 100, thereby improving the power output of the motor 1.
[0057] In addition, the rotating shaft 300 can pass through the bearing 400. In the axial direction of the motor 1, the bearing 400 is located between the end faces at both ends of the rotating shaft 300. The inner circumferential surface of the bearing 400 is completely in contact with the rotating shaft 300. The contact area between the bearing 400 and the rotating shaft 300 is maximized, avoiding a small contact area between the rotating shaft 300 and the bearing 400 due to processing errors and assembly errors. A groove 513 is provided at the bottom of the mounting groove 511, and the rotating shaft 300 extends into the groove 513. The groove 513 is used to accommodate a part of the rotating shaft 300 to avoid interference between the end cover 500 and the rotating shaft 300.
[0058] In addition, the cross-sectional area of the groove 513 is smaller than the cross-sectional area of the mounting groove 511. The cross-sectional area of the groove 513 and the cross-sectional area of the mounting groove 511 can both be constructed to be circular. In this way, on the one hand, the bottom wall of the mounting groove 511 can stop the bearing 400 to prevent the bearing 400 from being installed in the groove 513, which can serve as an indication that the installation is in place and make the installation more convenient. On the other hand, the inner circumferential surface of the groove 513 can limit the rotating shaft 300 to further improve the assembly accuracy.
[0059] That is to say, the end cover 500 can position the bearing 400 by providing the mounting groove 511, and can assist in positioning the rotating shaft 300 in the radial direction of the motor 1 by providing the groove 513, and can assist in positioning the rotating shaft 300 in the radial direction of the motor 1 by providing the protrusion 510, and can assist in positioning the motor 1 and the mounting bracket 920 by providing the movement 900. The end cover 500 can ensure that there is sufficient space to accommodate the rotating shaft 300, so as to ensure sufficient contact between the rotating shaft 300 and the bearing 400, so that the rotating shaft 300 moves more stably during rotation, and the torque output of the motor 1 is sufficient and stable.
[0060] Thus, the motor 1 according to the embodiment of the present application has the advantages of large output power, high installation precision and convenient installation.
[0061] like Figure 5 As shown, in the axial direction of the motor 1 , the dimension of the protrusion 510 beyond the outer surface of the rest of the end cover 500 is H1, the dimension of the bearing 400 is H2, and the ratio of H1 to H2 is not greater than 3.
[0062] That is, in the axial direction of the motor 1 , the dimension of the protrusion 510 beyond the outer surface of the rest of the end cover 500 is not greater than three times the axial length of the bearing 400 .
[0063] When H1>3×H2, the protrusion 510 exceeds the outer surface of the rest of the end cover 500 by too much, resulting in the end cover 500 being too large in the axial direction of the motor 1. The installation space required by the motor 1 in its axial direction is too large, making it inconvenient to apply the motor 1 to a small space, for example, it is inconvenient to apply the motor 1 to an electric toothbrush 2, and the cost of the motor 1 is also increased.
[0064] By setting the outer surface dimension of the protrusion 510 beyond the rest of the end cover 500 to be no greater than three times the axial length of the bearing 400, it is possible to avoid the protrusion dimension of the protrusion 510 being too large, and the axial dimension of the end cover 500 in the motor 1 being reduced, which is beneficial to reducing the axial dimension of the motor 1, making it easier for the motor 1 to be used in a narrow space, for example, the motor 1 is easier to be installed in the electric toothbrush 2, and the production cost of the end cover 500 is also reduced.
[0065] In addition, after the bearing 400 is installed in the installation groove 511, the protrusion 510 still has room to accommodate the end of the shaft 300, preventing the shaft 300 from extending too short into the bearing 400, thereby ensuring the reliability of the connection between the shaft 300 and the bearing 400.
[0066] like Figure 5 As shown, in the axial direction of the motor 1, the dimension of the protrusion 510 beyond the outer surface of the rest of the end cover 500 is H1, and H1 is not greater than 3 mm and not greater than 7 mm. For example, H1 can be 3 mm, 3.3 mm, 3.5 mm, 3.7 mm, 4 mm, 4.3 mm, 4.5 mm, 4.7 mm, 5 mm, 5.3 mm, 5.5 mm, 5.7 mm, 6 mm, 6.5 mm or 7 mm.
[0067] When H1 is less than 3 mm, the dimension of the protrusion 510 beyond the outer surface of the rest of the end cover 500 is too small. On the one hand, the dimension of the mounting groove 511 in the axial direction of the motor 1 is too small, and the bearing 400 cannot be effectively accommodated, causing the bearing 400 to easily detach from the mounting groove 511. On the other hand, the protrusion 510 may not have any extra space to accommodate the end of the rotating shaft 300, and the end of the rotating shaft 300 and the end of the bearing 400 may be flush, resulting in low connection reliability between the rotating shaft 300 and the bearing 400.
[0068] When H1 is greater than 7 mm, the protrusion 510 exceeds the outer surface of the rest of the end cover 500 by too much, resulting in the end cover 500 being too large in the axial direction of the motor 1. The installation space required by the motor 1 in its axial direction is too large, making it inconvenient to apply the motor 1 to a small space, for example, it is inconvenient to apply the motor 1 to an electric toothbrush 2. In addition, the cost of the end cover 500 is high, which leads to an increase in the cost of the motor 1.
[0069] When H1 is greater than or equal to 3 mm and less than or equal to 7 mm, on the one hand, the protrusion 510 can have a surplus space for accommodating the end of the shaft 300, ensuring that the end of the shaft 300 exceeds the end of the bearing 400, and the connection between the shaft 300 and the bearing 400 is stable, and the depth of the mounting groove 511 can be set larger to ensure the installation stability of the bearing 400. On the other hand, the size of the protrusion 510 will not be too large, and reducing the size of the protrusion 510 in the axial direction of the motor 1 is beneficial to reducing the size of the motor 1 in its axial direction. The motor 1 is easier to use in a small space, for example, the motor 1 is easier to install in the electric toothbrush 2, and the production cost of the end cover 500 is also reduced.
[0070] like Figure 5 As shown, in the axial direction of the motor 1 , the inner surface of the protrusion 510 is flush with the end surface of the stator case 250 , or the inner surface of the protrusion 510 is spaced apart from the stator case 250 .
[0071] For example, the inner surface of the protrusion 510 may be a plane, or the inner surface of the protrusion 510 may be an arc surface protruding outward. In this way, the inner surface of the protrusion 510 will not occupy the space in the stator housing 250, and the rotor assembly 100, the yoke 210, the permanent magnet 220 and the permanent magnet 220 in the stator housing 250 are not easily interfered by the protrusion 510, which is not only convenient for assembly, but also the size of the stator housing 250 in the axial direction of the motor 1 is small, which is conducive to shortening the size of the motor 1 in its axial direction.
[0072] like Figure 8 As shown, the distance W1 between the protrusion 510 and the outer edge of the end cover 500 is not less than 2 mm. In this way, there is sufficient space between the edge of the end cover 500 and the protrusion 510, and the mounting bracket 920 of the electric toothbrush 2 can be connected to the part of the end cover 500 except the protrusion 510 to fix the position of the motor 1, so that the protrusion 510 does not need to be connected to the mounting bracket 920, so the size of the protrusion 510 can be reduced, and then the size of the end cover 500 can be reduced, which is conducive to reducing the size of the motor 1.
[0073] like Figure 5 As shown, in the axial direction of the motor 1 , the inner side edge of the groove side wall 512 of the mounting groove 511 is flush with the inner side surface of the bearing 400 , or the inner side edge of the groove side wall 512 of the mounting groove 511 protrudes inward relative to the inner side surface of the bearing 400 .
[0074] That is to say, the depth of the mounting groove 511 is greater than the axial length of the bearing 400, and the bearing 400 can be completely located in the mounting groove 511. In this way, the connection area between the bearing 400 and the groove wall of the mounting groove 511 is larger, the installation of the bearing 400 is more stable, and the outer peripheral surface of the bearing 400 is blocked by the groove side wall 512, which can prevent the bearing 400 from being damaged by force during the assembly process and the transportation process.
[0075] In addition, the mounting groove 511 may include a guide section 540, which is located on a side of the mounting groove 511 close to the stator housing 250, and a diameter of the guide section 540 gradually increases in a direction close to the stator housing 250, so as to facilitate the installation of the bearing 400 into the mounting groove 511, wherein the end face of the bearing 400 facing the stator housing 250 and the side of the guide section 540 facing away from the stator housing 250 may be located in the same plane, or the bearing 400 may be further away from the stator housing 250 than the guide section 540, so as to effectively ensure the stability of the bearing 400 in the mounting groove 511.
[0076] like Figure 5 As shown, the motor 1 satisfies at least one of the following conditions:
[0077] In the axial direction of the motor 1 , the dimension L1 of the rotating shaft 300 beyond the outer side surface of the bearing 400 is no more than 2 mm;
[0078] In the axial direction of the motor 1, the distance L2 between the bearing 400 and the bottom wall of the groove 513 is not greater than 2 mm;
[0079] In the axial direction of the motor 1 , a distance L3 between the outer surface of the protrusion 510 and the bottom wall of the groove 513 is no greater than 2 mm.
[0080] For example, in the axial direction of the motor 1, the dimension L1 of the rotating shaft 300 extending beyond the outer side surface of the bearing 400 can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.4mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.4mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, or 2mm.
[0081] In the axial direction of the motor 1, the spacing L2 between the bearing 400 and the bottom wall of the groove 513 can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.4mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.4mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, or 2mm.
[0082] In the axial direction of the motor 1, the spacing L3 between the outer surface of the protrusion 510 and the bottom wall of the groove 513 can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.4mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.4mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, or 2mm.
[0083] In this way, the end cover 500 has a small size in the axial direction of the motor 1 , which is beneficial to reducing the axial size of the motor 1 , making it easier for the motor 1 to be installed in a narrow space, such as an electric toothbrush 2 , thereby reducing the cost of the motor 1 .
[0084] like Figure 3-Figure 5 As shown, the motor 1 further includes an elastic member 600, which can be a corrugated spring sheet, and multiple points of contact can be formed between the elastic member 600 and the bearing 400, and multiple force points are more evenly distributed along the circumference of the bearing 400. The elastic member 600 is located between the bearing 400 and the bottom wall of the mounting groove 511 and can be elastically deformed.
[0085] In this way, when the end cover 500 or the bearing 400 has a processing error, or when the components of the motor 1 have an assembly error in the axial direction of the motor 1, the elastic member 600 can absorb the above-mentioned processing error and assembly error through the amplitude of its own elastic deformation, thereby ensuring that the size of the motor 1 in its axial direction meets expectations.
[0086] In addition, in the axial direction of the motor 1 , the size of the bearing 400 is H2 , the size of the elastic member 600 in a natural state is H3 , the depth of the mounting groove 511 is H4 , and the sum of H2 and H3 is less than H4 .
[0087] In this way, when the bearing 400 and the elastic member 600 are both installed in the installation groove 511, even if the elastic member 600 is not subjected to force and undergoes elastic deformation, the bearing 400 will not protrude from the side of the installation groove 511 facing the stator housing 250, thereby ensuring that the bearing 400 can always be located in the installation groove 511 to determine the axial installation dimensions of the various components of the motor 1.
[0088] like Figure 6-Figure 7 As shown, the end cover 500 is provided with a wire hole 501, which passes through the end cover 500 along the axial direction of the motor 1. The lead wire of the coil 110 passes through the wire hole 501 and is connected to the circuit board 910 or power supply and other structures in the electric toothbrush 2. The coil 110 can be energized to generate a magnetic field.
[0089] In the radial direction of the motor 1, the wire hole 501 is located between the edge of the end cover 500 and the protrusion 510, and the spacing W3 between the wire hole 501 and the protrusion 510 is not greater than 2 mm. For example, the spacing between the wire hole 501 and the protrusion 510 can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm or 2 mm.
[0090] Compared with the prior art in which the bearing is located outside the mounting groove, since the bearing 400 of the motor 1 of the embodiment of the present application is installed in the mounting groove 511 of the protrusion 510, the outer diameter of the protrusion 510 will increase accordingly. Therefore, by reducing the distance between the protrusion 510 and the wire hole 501, it is possible to avoid increasing the space required for the protrusion 510 and the wire hole 501 as a whole. This allows the end cover 500 to have sufficient space to set other structures without increasing the cross-sectional area of the end cover 500, thereby improving the space utilization of the end cover 500.
[0091] like Figure 6-Figure 8 , Fig.10 as well as Fig.11As shown, the above-mentioned motor 1 has a first radial direction (the direction indicated by arrow A in the accompanying drawing) and a second radial direction (the direction indicated by arrow B in the accompanying drawing), the first radial direction and the second radial direction are perpendicular to each other, and the spacing between the inner surfaces of the stator case 250 on both sides relative to each other in the first radial direction is greater than the spacing between the inner surfaces of the stator case 250 on both sides relative to each other in the second radial direction.
[0092] The rotor assembly 100 further includes a rotor core 120 and two coils 110 . The rotating shaft 300 is inserted through the rotor core 120 , sleeved on the rotating shaft 300 , and is transmission-connected to the rotating shaft 300 . The two coils 110 are disposed on opposite sides of the rotor core 120 in a first radial direction.
[0093] The inner circumference of the two opposite side walls of the stator case 250 in the first radial direction can be configured as an outwardly convex arc surface, and the inner circumference of the two opposite side walls of the stator case 250 in the second radial direction can be configured as a plane. The two coils 110 rotate between the two opposite side walls of the stator case 250 in the first radial direction, and the two opposite side walls of the stator case 250 in the second radial direction are used to stop and limit the rotor core 120 to prevent the rotor assembly 100 from rotating excessively and causing the lead wires of the coils 110 to be torn off.
[0094] The wire-passing hole 501 is disposed between the edge of the end cover 500 in the second radial direction and the protrusion 510. There may be two wire-passing holes 501, which are disposed on opposite sides of the protrusion 510 in the second radial direction. In this way, each wire-passing hole 501 is located between two coils 110, which can reduce the overall length of the lead wires of the two coils 110, improve the convenience of routing, and reduce costs.
[0095] like Figure 8 In the first radial direction, the size L4 of the wire hole 501 is not less than 0.8 mm and not more than 1.8 mm. For example, in the first radial direction, the size L4 of the wire hole 501 can be 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm or 1.8 mm.
[0096] In the first radial direction, when the size L4 of the wire hole 501 is less than 0.8 mm, the size of the wire hole 501 is too small, which is not conducive to threading, affecting production efficiency, and during the threading process, the lead wire of the coil 110 is easy to rub against the hole wall of the wire hole 501, resulting in wear of the wire;
[0097] In the first radial direction, when the size L4 of the wire hole 501 is greater than 1.8 mm, the size of the wire hole 501 is too large, which will reduce the processing space of other structures on the end cover 500, affect the design of the end cover 500, and also affect the structural strength of the end cover 500. In addition, the movable space of the lead wire of the coil 110 in the wire hole 501 is too large, and the wire is more likely to shake. During use, the lead wire of the coil 110 is likely to rub against the hole wall of the wire hole 501, resulting in wear of the wire.
[0098] In the first radial direction, when the size L4 of the wire passing hole 501 is greater than or equal to 0.8 mm and less than or equal to 1.8 mm, not only is the threading process convenient, but the lead wire of the coil 110 is not easy to rub against the hole wall of the wire passing hole 501, thereby ensuring the normal use of the lead wire of the coil 110. In addition, during use, the lead wire of the coil 110 is not easy to shake drastically in the wire passing hole 501, and the lead wire of the coil 110 is not easy to rub against the hole wall of the wire passing hole 501, thereby ensuring the normal use of the lead wire of the coil 110. The wire passing hole 501 will not excessively occupy the space of the end cover 500, and the setting space for the remaining structures on the end cover 500 is larger, which is beneficial to the structural design of the end cover 500, and the structural strength of the end cover 500 is relatively high.
[0099] like Figure 6-Figure 7 The wire hole 501 is located in the central area of the motor 1 in the first radial direction. For example, the central plane of the motor 1 in the first radial direction passes through the wire hole 501, and the wire hole 501 is symmetrically arranged about the central plane of the motor 1 in the first radial direction.
[0100] In this way, the distance between the lead wires of the two coils 110 and the wire hole 501 is roughly the same, which facilitates the lead wires of the coils 110 to be led out from the wire hole 501, and the lengths of the lead wires of the two coils 110 can be roughly the same. During the assembly process, there is no need to distinguish the installation positions of the two coils 110, which is conducive to improving assembly efficiency. In addition, the structural strength of the end cover 500 is uniform, and it is not easy to have problems such as damage to the end cover 500 due to uneven force.
[0101] like Fig.10 , Fig.12 and Fig.13 The motor 1 further comprises a stopper 700 and an anti-wear member 800. The stopper 700 is sleeved on the rotating shaft 300, and the stopper 700 stops at the side of the bearing 400 facing away from the end cover 500. The anti-wear member 800 is sleeved on the rotating shaft 300, and the anti-wear member 800 is located on the side of the stopper 700 facing away from the bearing 400. In the radial direction of the motor 1, the outer edge of the anti-wear member 800 is located between the outer edge of the stopper 700 and the inner side wall of the wire hole 501.
[0102] For example, the limiter 700 may be made of a material with relatively high strength, such as a copper ring, an iron ring, etc.; the anti-wear part 800 may be made of a flexible material, such as wool felt and rubber, etc.
[0103] By setting a limit member 700, the relative position of the limit member 700 and the rotating shaft 300 in the axial direction of the motor 1 is fixed, and the limit member 700 stops at a side of the bearing 400 that is away from the end cover 500, and the bearing 400 is fixed in the installation groove 511. The limit member 700 and the elastic member 600 clamp the bearing 400 from both axial ends of the motor 1 to prevent the bearing 400 from moving relative to the rotating shaft 300.
[0104] During the rotation of the rotor assembly 100 relative to the stator assembly 200, the rotating shaft 300 will be driven to rotate relative to the stator assembly 200. By providing the anti-wear part 800, the lead wire of the coil 110 can be placed on the outer peripheral surface of the anti-wear part 800 to avoid contact between the lead wire of the coil 110 and the limiting part 700 and the rotating shaft 300, thereby avoiding wear between the lead wire of the coil 110 and the limiting part 700 or the rotating shaft 300. When the anti-wear part 800 and the lead wire move relative to each other, the anti-wear part 800 is not easy to cause wear of the lead wire, thereby reducing the probability of damage to the lead wire and extending the service life of the lead wire.
[0105] like Figure 4 , Figure 5 as well as Fig. 9 As described above, the end cover 500 further includes a connecting portion 520 and an inserting portion 530 .
[0106] The connecting portion 520 is connected to the protruding portion 510 and extends along the circumferential direction of the protruding portion 510, and the connecting portion 520 stops at the end surface of the stator housing 250. The inserting portion 530 is connected to the inner side surface of the connecting portion 520 and inserted into the stator housing 250. Among them, a guide structure 550 is provided at one end of the inserting portion 530 facing away from the connecting portion 520, and in the axial direction of the motor 1, the outer circumferential surface of the guide structure 550 gradually approaches the rotating shaft 300 from the outside to the inside.
[0107] By providing the connecting portion 520, the relative position between the end cover 500 and the stator case 250 in the axial direction of the motor 1 can be limited to prevent the end cover 500 from excessively penetrating into the stator case 250. In addition, the connecting portion 520 can cover the opening 251 to prevent the components in the stator case 250 from being directly exposed to the air, thereby reducing the probability of damage to the motor 1.
[0108] By providing the insertion portion 530, the contact area between the end cover 500 and the stator shell 250 can be increased. The outer circumferential surface of the insertion portion 530 contacts the inner circumferential surface of the stator shell 250 to improve the connection strength between the end cover 500 and the stator shell 250. The relative position between the end cover 500 and the stator shell 250 is more stable, and pre-positioning between the end cover 500 and the stator shell 250 can be achieved, which is convenient for automated assembly.
[0109] In addition, a guide structure 550 is provided, and the area surrounded by the outer contour of the cross section of the guide structure 550 gradually decreases, which makes it easier to insert the insertion portion 530 into the stator case 250 .
[0110] like Fig. 9 In the radial direction of the motor 1, the size of the guide structure 550 is not less than 0.8 mm. In the radial direction of the motor 1, the size of the guide structure 550 can be 0.8 mm, 0.83 mm, 0.85 mm, 0.87 mm, 0.9 mm, 0.93 mm, 0.95 mm, 0.97 mm or 1 mm.
[0111] In the radial direction of the motor 1, when the minimum dimension of the guide structure 550 is less than 0.8 mm, at least a portion of the guide structure 550 has low structural strength and is easily damaged by force. Therefore, in the radial direction of the motor 1, by setting the dimension of the guide structure 550 to be greater than or equal to 0.8 mm, the structural strength of the guide structure 550 can be ensured, and the probability of the guide structure 550 being damaged by force can be reduced during the assembly process of the motor 1 and the transportation process of the end cover 500.
[0112] like Figure 3 , Figure 5 and Fig.11 The stator assembly 200 further includes a yoke 210 and a permanent magnet 220. The yoke 210 is disposed between the stator housing 250 and the rotor assembly 100, and the permanent magnet 220 is disposed on the inner circumferential surface of the yoke 210. In the axial direction of the motor 1, the spacing W2 between the insertion portion 530 and the yoke 210 is not less than 0.5 mm and not more than 3 mm. For example, the spacing W2 between the insertion portion 530 and the yoke 210 may be 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm or 3 mm.
[0113] For example, the yoke 210 can be made of a soft magnetic material that does not generate a magnetic field (i.e., magnetic lines of force) itself and only plays a role in transmitting magnetic lines of force in the magnetic circuit. For example, the yoke 210 can be made of soft iron, A3 steel, or a soft magnetic alloy with relatively high magnetic permeability. The permanent magnet 220 refers to a magnet that can maintain its magnetism for a long time. The permanent magnet 220 can be made of artificial magnetic steel (iron-nickel-cobalt magnetic steel, etc.) or magnets. The permanent magnet 220 is used to generate a magnetic field. The magnetic field of the permanent magnet 220 interacts with the magnetic field of the coil 110 to drive the rotor assembly 100 to rotate relative to the stator assembly 200.
[0114] The distance W2 between the insertion portion 530 and the yoke 210 is less than 0.5 mm. The distance between the insertion portion 530 and the yoke 210 is small, and there is not enough margin space to absorb the processing error and the assembly error. During the assembly process of the motor 1, interference may occur between the insertion portion 530 and the yoke 210.
[0115] The distance W2 between the insertion portion 530 and the yoke 210 is greater than 3 mm. The distance between the insertion portion 530 and the yoke 210 is relatively large, which causes the axial size of the housing of the motor 1 to also need to be increased. The motor 1 is not suitable for use in a narrow space, and the cost increases. Alternatively, the axial size of the yoke 210 of the motor 1 needs to be reduced, which affects the axial size of the permanent magnet 220 of the motor 1, and the output power of the motor 1 decreases.
[0116] By setting the spacing W2 between the insertion portion 530 and the yoke 210 to be greater than or equal to 0.5 mm and less than or equal to 3 mm, there is sufficient space between the insertion portion 530 and the yoke 210 to avoid the situation where the assembly cannot be completed or the assembly is unstable due to processing errors and assembly errors, thereby ensuring the stability of the mass production process of the motor 1 and improving the product yield. In addition, the axial size of the yoke 210 of the motor 1 can be increased to increase the output power of the motor 1, or the axial size of the motor 1 can be reduced, which is conducive to the miniaturization of the motor 1.
[0117] like Fig.15 As shown, the movement 900 further includes a circuit board 910 and a mounting bracket 920, and the circuit board 910 is connected to the motor 1. In the radial direction of the electric toothbrush 2, the circuit board 910 and the motor 1 are arranged on opposite sides of the mounting bracket 920. The end cover 500 is provided with a wire hole 501, and the wire hole 501 is located between the protrusion 510 and the mounting bracket 920.
[0118] That is to say, the distance between the side of the end cover 500 close to the mounting bracket 920 and the wire hole 501 is smaller than the distance between the side of the end cover 500 far from the mounting bracket 920 and the wire hole 501, so that the distance between the wire hole 501 and the circuit board 910 is also closer, which can shorten the lead length between the coil 110 and the circuit board 910, facilitate line layout, and save costs.
[0119] In addition, since the circuit board 910 and the motor 1 are arranged on opposite sides of the mounting bracket 920, interference is not likely to occur between the circuit board 910 and the motor 1, which facilitates the layout of the movement 900, and when the motor 1 vibrates, the mounting bracket 920 can play a certain buffering role and reduce the vibration amplitude of the circuit board 910.
[0120] like Fig.15 As shown, the mounting bracket 920 clamps the two axial ends of the motor 1, and the mounting bracket 920 contacts the outer surface of the end cover 500 except the protrusion 510. In other words, the mounting bracket 920 applies a clamping force to the motor 1 from the two axial ends of the motor 1 to fix the relative position between the motor 1 and the mounting bracket 920, so that the mounting stability of the motor 1 can be ensured without the need for fixing with the protrusion 510 or increasing the size of the protrusion 510.
[0121] like Fig.15 As shown, the mounting bracket 920 includes a first frame 921 and a second frame 922 , the first frame 921 and the second frame 922 are detachably connected, and the first frame 921 and the second frame 922 are arranged along the radial direction of the motor 1 .
[0122] For example, the first frame 921 and the second frame 922 are arranged along a first radial direction, or the first frame 921 and the second frame 922 are arranged along a second radial direction.
[0123] In this way, the mounting bracket 920 and the motor 1 can be assembled and disassembled more conveniently, which is beneficial to improving the assembly efficiency of the electric toothbrush 2.
[0124] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of this application, it should be understood that if the terms "up", "down", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, it is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limitations on this application. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.
[0125] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.
Claims
1. A motor, characterized in that: include: A stator assembly, the stator assembly comprising a stator shell, an end of the stator shell being provided with an opening; An end cover, the end cover is connected to the stator shell and is used to cover the opening, the end cover comprises a protrusion, in the axial direction of the motor, the protrusion exceeds the outer surface of the remaining part of the end cover, the inner surface of the protrusion is provided with a mounting groove, the bottom of the mounting groove is provided with a groove, and the cross-sectional area of the groove is smaller than the cross-sectional area of the mounting groove; A bearing, the bearing is arranged in the mounting groove, and in the axial direction of the motor, the bearing is located outside the stator housing; a rotor assembly, the rotor assembly being disposed in the stator housing and rotatable relative to the stator assembly; A rotating shaft is provided through the bearing and the rotor assembly, the rotor assembly drives the rotating shaft to rotate relative to the stator assembly, and a part of the rotating shaft is located in the groove.
2. The motor according to claim 1, characterized in that In the axial direction of the motor, the dimension of the protrusion beyond the outer surface of the rest of the end cover is H1, the dimension of the bearing is H2, and the ratio of H1 to H2 is not greater than 3.
3. The motor according to claim 1, characterized in that In the axial direction of the motor, the dimension of the protrusion beyond the outer surface of the rest of the end cover is H1, and H1 is not greater than 3 mm and not greater than 7 mm.
4. The motor according to claim 1, characterized in that In the axial direction of the motor, the inner surface of the protrusion is flush with the end surface of the stator shell, or the inner surface of the protrusion is spaced apart from the stator shell.
5. The motor according to claim 1, characterized in that The distance between the protrusion and the edge of the end cover is not less than 2 mm.
6. The motor according to claim 1, characterized in that In the axial direction of the motor, the inner side edge of the groove side wall of the installation groove is flush with the inner side surface of the bearing, or the inner side edge of the groove side wall of the installation groove protrudes inward relative to the inner side surface of the bearing.
7. The motor according to claim 1, characterized in that The motor meets at least one of the following requirements: In the axial direction of the motor, the dimension of the rotating shaft beyond the outer side surface of the bearing is no more than 2 mm; In the axial direction of the motor, the distance between the bearing and the bottom wall of the groove is no more than 2 mm; In the axial direction of the motor, the distance between the outer surface of the protrusion and the bottom wall of the groove is no more than 2 mm.
8. The motor according to claim 1, characterized in that Also includes: an elastic member, the elastic member being located between the bearing and the bottom wall of the mounting groove and being elastically deformable; Wherein, in the axial direction of the motor, the size of the bearing is H2, the size of the elastic member in a natural state is H3, the depth of the mounting groove is H4, and the sum of H2 and H3 is less than H4.
9. The motor according to claim 1, characterized in that The end cover is provided with a wire hole, and the wire hole passes through the end cover along the axial direction of the motor; In the radial direction of the motor, the wire passing hole is located between the edge of the end cover and the protruding portion, and the distance between the wire passing hole and the protruding portion is no more than 2 mm.
10. The motor according to claim 9, characterized in that The motor has a first radial direction and a second radial direction, the first radial direction and the second radial direction are perpendicular to each other, and the distance between the inner surfaces of the stator shell on two opposite sides in the first radial direction is greater than the distance between the inner surfaces of the stator shell on two opposite sides in the second radial direction; The rotor assembly further includes a rotor core and two coils, the rotating shaft is passed through the rotor core, sleeved on the rotating shaft and is transmission-connected with the rotating shaft, and the two coils are disposed on opposite sides of the rotor core in the first radial direction; Wherein, the wire passing hole is arranged between the edge of the end cover in the second radial direction and the protruding portion, and the wire passing hole is located in the central area of the motor in the first radial direction.
11. The motor according to claim 10, characterized in that In the first radial direction, the size of the wire hole is not less than 0.8 mm and not more than 1.8 mm.
12. The motor according to claim 9, characterized in that Also includes: A limiting member, wherein the limiting member is sleeved on the rotating shaft and abuts against a side surface of the bearing facing away from the end cover; An anti-wear member, the anti-wear member is sleeved on the rotating shaft, and the anti-wear member is located on a side of the limiting member facing away from the bearing; Wherein, in the radial direction of the motor, the outer edge of the anti-wear component is located between the outer edge of the limiting component and the inner side wall of the wire passing hole.
13. The motor according to claim 1, characterized in that The end cap also includes: A connecting portion, the connecting portion is connected to the protruding portion and extends along the circumferential direction of the protruding portion, and the connecting portion stops at an end surface of the stator shell; an inserting portion, the inserting portion being connected to the inner side surface of the connecting portion and being inserted into the stator housing; A guide structure is provided at one end of the insertion portion facing away from the connection portion, and in the axial direction of the motor, an outer peripheral surface of the guide structure gradually approaches the rotating shaft from the outside to the inside.
14. The motor according to claim 13, characterized in that The stator assembly further comprises: a yoke disposed between the stator housing and the rotor assembly; A permanent magnet, the permanent magnet being arranged on the inner peripheral surface of the yoke; Wherein, in the axial direction of the motor, the distance between the insertion portion and the yoke is not less than 0.5 mm and not more than 3 mm.
15. An electric toothbrush, characterized in that: include: Handle shell; A movement, the movement comprising a motor according to any one of claims 1-14, the movement being arranged in the handle shell.
16. The electric toothbrush according to claim 15, characterized in that The movement also includes: A circuit board connected to the motor; A mounting bracket, in the radial direction of the electric toothbrush, the circuit board and the motor are arranged on opposite sides of the mounting bracket, and the mounting bracket clamps the axial ends of the motor; Wherein, the end cover is provided with a wire passing hole, and the wire passing hole is located between the protruding portion and the mounting bracket.
17. The electric toothbrush according to claim 16, characterized in that: The mounting bracket comprises: A first frame and a second frame, wherein the first frame and the second frame are detachably connected, and the first frame and the second frame are arranged along the radial direction of the motor.