Electric motor and power tool

Abstract

The application discloses a motor and an electric tool. The motor comprises a motor shaft, a rotor assembly sleeved on the motor shaft, and a stator assembly arranged around the motor shaft. The stator assembly comprises a stator core, a stator end plate connected to the stator core, and a coil wound on the stator end plate. A side of the stator end plate away from the stator core is provided with a plurality of supports along the circumference of the motor shaft. The support comprises a main body wound with the coil and a bent portion limiting the coil. The main body is vertically arranged on the stator end plate, the bottom end of the main body is fixed to the stator end plate, the top end of the main body is fixed to the bent portion, and the main body is at least partially in an arc shape circumferentially surrounding the motor shaft. By arranging a plurality of supports along the circumference of the motor shaft, the circumferential space proportion of the support structure is reduced, and the bent portion is arranged on the support, so that the winding is not scattered and the winding size is reduced.

Description

Technical Field

[0001] This application relates to the field of tool technology, and in particular to an electric motor and a power tool. Background Technology

[0002] Currently, the stator support of a motor provides winding support, plasticity, and insulation. However, existing supports tend to increase the effective size of the windings, which in turn increases the resistance. This is because the existing support structure has a material thickness of about 1mm on the plastic surface when supporting the internal windings.

[0003] The increased material thickness of the support's molding surface leads to an increase in the effective winding size, directly enlarging the coil's inner diameter and reducing space utilization. Increased winding size, accompanied by increased conductor length, causes increased resistance, thus affecting motor efficiency. However, directly removing the central portion of the support to reduce the inner diameter results in winding fraying due to a lack of mechanical support. Utility Model Content

[0004] To address the shortcomings of existing technologies, this application provides a motor and power tool that can reduce resistance while ensuring that the windings do not unravel.

[0005] This application provides an electric motor, including:

[0006] Motor shaft;

[0007] The rotor assembly is mounted on the motor shaft;

[0008] A stator assembly, arranged around the motor shaft, includes a stator core, a stator end plate connected to the stator core, and coils wound on the stator end plate. Multiple supports are arranged circumferentially along the motor shaft on the side of the stator end plate away from the stator core.

[0009] The bracket includes a main body for winding the coil and a bent portion for limiting the coil. The main body is vertically disposed on the stator end plate. The bottom end of the main body is fixed to the stator end plate, and the top end of the main body is fixed to the bent portion. The main body is at least partially arc-shaped, circumferentially surrounding the motor shaft.

[0010] A further improvement is that the main bodies of the multiple supports are located on the same circular arc formed circumferentially around the motor shaft.

[0011] A further improvement is that the sum of the circumferential intervals between the main bodies of the plurality of supports is greater than the circumferential length of the main bodies of the plurality of supports.

[0012] A further improvement is that the circumferential length of any one of the main bodies is less than the circumferential interval between any pair of adjacent main bodies.

[0013] A further improvement is that the sum of the circumferential intervals between the main bodies of the plurality of supports is not less than twice the circumferential length of the main bodies of the plurality of supports.

[0014] A further improvement is that the bending direction of the bent portion does not intersect with the axial direction of the motor shaft.

[0015] A further improvement is that the main body, the bent portion, and the stator end plate are integrally formed.

[0016] A further improvement is as follows: the brackets are arranged in pairs on the stator end plate, and the brackets are arranged in a centrally symmetrical manner.

[0017] A further improvement is that the projection of the bent portion along the axial direction of the motor shaft is at least partially located on the stator end plate.

[0018] This application provides an electric tool, including the aforementioned motor.

[0019] The motor and power tool provided in this application embodiment reduce the circumferential space ratio of the support structure by arranging multiple supports along the circumference of the motor shaft, and by setting a bending part on the support, it can ensure that the winding does not unravel while reducing the winding size, thereby reducing resistance and improving motor performance. Attached Figure Description

[0020] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0021] Figure 1 This is a front view of a stator assembly provided in some embodiments of this application;

[0022] Figure 2 This is a top view of a stator assembly provided in some embodiments of this application;

[0023] Figure 3 This is a top view of a stator end plate provided in some embodiments of this application;

[0024] Figure 4 This is a front view of the stator end plate provided in some embodiments of this application. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been presented in the various embodiments of this application to enable readers to better understand this application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in this application can be implemented. The division of the various embodiments below is for the convenience of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0027] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0028] like Figures 1 to 4 As shown, some embodiments of the present application provide an electric motor including a motor shaft, a rotor assembly, and a stator assembly 6. The rotor assembly is mounted on the motor shaft, and the stator assembly 6 is arranged around the motor shaft. The stator assembly 6 includes a stator core, a stator end plate 1 connected to the stator core, and a coil 2 wound on the stator end plate 1.

[0029] Multiple supports 3 are arranged circumferentially along the motor shaft on the side of the stator end plate 1 away from the stator core. The stator end plate 1 is generally annular, and the supports 3 are spaced apart circumferentially on the stator end plate 1. Each support 3 includes a main body 4 on which a coil 2 is wound and a bent portion 5 that limits the position of the coil 2. Preferably, the main body 4, the bent portion 5 and the stator end plate 1 are integrally formed. The bent portion 5 and the main body 4 generally form an L-shape, and the bent portion 5 limits the position of the coil 2 below it, restricting the height of the coil 2 and preventing the wire from fraying. The main body 4 is vertically arranged on the stator end plate 1, with the bottom end of the main body 4 fixed to the stator end plate 1 and the top end of the main body 4 fixed to the bent portion 5. The main body 4 is at least partially arc-shaped, circumferentially surrounding the motor shaft as an axis; preferably, the entire main body 4 is arc-shaped, circumferentially surrounding the motor shaft as an axis.

[0030] By setting multiple supports 3 along the circumference of the motor shaft, the circumferential space ratio of the support 3 structure is reduced, and a bending part 5 is set on the support 3. This ensures that the winding does not come loose while reducing the winding size, thereby reducing resistance and improving motor performance.

[0031] The motor shaft is the power output part of the motor, which can be connected to the actuator of the power tool to transmit the driving force and motion generated by the motor to the end effector, thereby realizing the corresponding machining operation. The motor shaft is fixedly connected to the rotor assembly and can rotate synchronously with the rotor assembly. The motor shaft has a certain length so that it can be connected to the input end of the transmission mechanism in the power tool.

[0032] The rotor assembly is the rotating part of the motor. The rotor assembly includes magnets, which are fixed to the inner wall of the end cover or embedded in the mounting slot of the rotor core, forming an external rotor motor or an internal rotor motor. The rotor assembly can rotate under the magnetic field generated by the stator assembly 6, thereby driving the motor shaft to rotate synchronously.

[0033] The stator assembly 6 is the stationary part of the motor, and a housing can be installed around it for protection. The stator assembly 6 includes a stator core, stator end plates 1, and coils 2. The stator core is not only a key part of the motor's magnetic circuit but also serves to fix and support the coils 2. The coils 2 can be connected to an external circuit via leads, and the cable ends can be equipped with wiring structures for electrical connection. When current flows through the coils 2, the generated magnetic field is collected and concentrated in the stator core, thereby amplifying and guiding it to the rotor assembly, driving the rotor assembly to rotate. The stator end plates 1 provide electrical isolation between the stator core and the coils 2, and also provide winding support for the coils 2. The stator assembly 6 as a whole is rotatably connected to the motor shaft.

[0034] In one embodiment, the main bodies 4 of multiple supports 3 are located on the same arc circumferentially formed with the motor shaft as the axis. Specifically, the main bodies 4 of the multiple supports 3 are arranged circumferentially along the same circle centered on the motor shaft, and the main bodies 4 themselves are also arc-shaped. The arc segments of the main bodies 4 of different supports 3 maintain the same radius of curvature, forming a concentric circle structure to ensure equidistant fit with the rotor components. This concentric arc layout ensures a uniform distribution of the electromagnetic field, making the magnetic field generated by the coil 2 more symmetrical, which is beneficial to improving the smoothness of motor operation. The uniformly distributed supports 3 can form a support network with each other to jointly resist the centrifugal force and electromagnetic force generated during operation.

[0035] The main bodies 4 of the multiple supports 3 are spaced circumferentially in pairs, with the interval length calculated as circumferential length. In one embodiment, the sum of the circumferential intervals between the main bodies 4 of the multiple supports 3 is greater than the sum of the circumferential lengths of the main bodies 4 of the multiple supports 3. For example, when there are three supports 3, including a first support 3, a second support 3, and a third support 3; the interval between the first support 3 and the second support 3 is added together with the interval between the second support 3 and the third support 3, and then the interval between the third support 3 and the first support 3 is further added together to obtain the sum of the circumferential intervals between the main bodies 4 of the multiple supports 3. The sum of the circumferential lengths of the main bodies 4 of the first support 3, the second support 3, and the third support 3 is obtained. The larger the circumferential interval between the main bodies 4, the smaller the inner diameter of the coil 2, and the relatively improved motor performance can be achieved. Preferably, the sum of the circumferential intervals between the main bodies 4 of the multiple supports 3 is not less than twice the circumferential length of the main bodies 4 of the multiple supports 3.

[0036] In another embodiment, the circumferential length of any one body 4 is less than the circumferential interval between any pair of adjacent bodies 4. Each support body 4 has a shorter arc length in the circumferential direction, while the blank area between supports 3 is relatively large, forming a distinct spacing distribution. The larger the circumferential interval between bodies 4, the smaller the inner diameter of the coil 2, and the relatively improved motor performance can be achieved. In addition, this design increases the heat dissipation area, which is beneficial for heat dissipation during motor operation and also provides convenience for cable routing. Although the support area of ​​a single support 3 is reduced, the rigidity requirements of the overall structure can still be guaranteed by reasonably increasing the number of supports 3.

[0037] In order to optimize the spatial layout and ensure that the multiple bending parts 5 are subjected to uniform force, in one embodiment, the bending direction of the bending part 5 does not intersect with the axial direction of the motor shaft, forming a staggered layout in three-dimensional space.

[0038] In one embodiment, the brackets 3 are arranged in pairs on the stator end plate 1, and the brackets 3 are centrally symmetrical. Each pair of brackets 3 is symmetrically distributed at 180°, which achieves better dynamic performance of the motor while ensuring structural strength.

[0039] In one embodiment, the projection of the bent portion 5 along the axial direction of the motor shaft is at least partially located on the stator end plate 1. This design, where the projection of the bent portion 5 along the axial direction of the motor shaft is at least partially located on the stator end plate 1, optimizes the mechanical coupling relationship in three-dimensional space. Specifically, the coil 2 is constrained at its top by the bent portion 5 and at its bottom by the force exerted by the stator end, thus ensuring good confinement of the coil 2.

[0040] Some embodiments of this application also provide a power tool, which includes the aforementioned motor. The power tool can be a common handheld power tool, such as an electric screwdriver, electric grinder, or electric reciprocating saw. The power tool can also be a larger, push-type tool, such as a lawnmower. The actuating components of the power tool are driven by a motor to perform the corresponding processing operations.

[0041] Those skilled in the art will understand that the above embodiments are specific implementations of this application, and in practical applications, various changes can be made in form and detail without departing from the spirit and scope of this application.

Claims

1. An electric motor, characterized in that, include: Motor shaft; The rotor assembly is mounted on the motor shaft; A stator assembly, arranged around the motor shaft, includes a stator core, a stator end plate connected to the stator core, and coils wound on the stator end plate. Multiple supports are arranged circumferentially along the motor shaft on the side of the stator end plate away from the stator core. These supports are arranged in pairs on the stator end plate, and are centrally symmetrical about each other. The bracket includes a main body on which the coil is wound and a bent portion that limits the position of the coil. The main body is vertically disposed on the stator end plate. The bottom end of the main body is fixed to the stator end plate, and the top end of the main body is fixed to the bent portion. The main body is at least partially arc-shaped around the motor shaft as the axis. The main bodies of the multiple brackets are located on the same circular arc formed circumferentially with the motor shaft as the axis; The sum of the circumferential spacings between the main bodies of the plurality of supports is greater than the sum of the circumferential lengths of the main bodies of the plurality of supports.

2. The motor according to claim 1, characterized in that: The sum of the circumferential intervals between the main bodies of the plurality of supports is not less than twice the sum of the circumferential lengths of the main bodies of the plurality of supports.

3. The motor according to claim 1, characterized in that: The circumferential length of any one of the main bodies is less than the circumferential interval between any pair of adjacent main bodies.

4. The motor according to claim 1, characterized in that: The bending direction of the bent portion does not intersect with the axial direction of the motor shaft.

5. The motor according to claim 1, characterized in that: The main body, the bent portion, and the stator end plate are integrally formed.

6. The motor according to claim 1, characterized in that: The projection of the bent portion along the axial direction of the motor shaft is at least partially located on the stator end plate.

7. A power tool, characterized in that, Includes the motor as described in any one of claims 1 to 6.

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