External rotor motor and electric tool

Abstract

The utility model relates to an external rotor motor and an electric tool, the external rotor motor comprises a stator assembly and a rotor assembly, the rotor assembly is sleeved outside the stator assembly, the stator assembly comprises a stator iron core, a stator support and a coil, the stator iron core is sleeved on the stator support, and the coil is sleeved on the stator support. The coil is wound on the stator iron core, the rotor assembly comprises a rotor casing and a rotating shaft, the rotating shaft is arranged in the rotor casing in a penetrating mode, and the outer rotor motor further comprises an insulation assembly. The insulation assembly comprises a first insulation layer wrapping the stator core, a second insulation layer located between the stator support and the stator core, and a third insulation layer located between the rotating shaft and the rotor casing. According to the utility model, the external rotor motor is provided with a plurality of insulating layers, so that the external rotor motor has a multi-insulating structure, and the insulating property requirement of the external rotor motor in a high-voltage environment can be met.

Description

Technical Field

[0001] The present application relates to the field of motor technology, and in particular to an outer rotor motor and an electric tool. Background Art

[0002] At present, outer rotor motors are mostly used in low-voltage conditions, and the insulation requirements for the outer rotor motors themselves are not high. With the development of the industry, the application scenarios of outer rotor motors are gradually expanding, and outer rotors are gradually being used in high-voltage environments. As outer rotor motors begin to be used in high-voltage conditions, existing outer rotor motors lack sufficient insulation design.

[0003] In view of this, it is indeed necessary to provide an improved outer rotor motor and electric tool to overcome the defects of the prior art. Utility Model Content

[0004] In view of the deficiencies in the prior art, the purpose of the utility model is to provide an outer rotor motor and an electric tool with excellent insulation capability.

[0005] The present application provides an outer rotor motor, comprising a stator assembly and a rotor assembly, wherein the rotor assembly is sleeved on the outside of the stator assembly, the stator assembly comprises a stator core, a stator bracket and a coil, the stator core is sleeved on the stator bracket, the coil is wound on the stator core, the rotor assembly comprises a rotor casing and a rotating shaft, the rotating shaft is passed through the rotor casing, the outer rotor motor further comprises an insulating component, the insulating component comprises a first insulating layer coated on the stator core, a second insulating layer located between the stator bracket and the stator core, and a third insulating layer located between the rotating shaft and the rotor casing

[0006] A further improved solution is: the first insulating layer includes a main insulating portion and a protruding portion connected to the main insulating portion, the coil is wound on the stator core through the main insulating portion, and the protruding portion extends axially from one side end surface of the stator core.

[0007] A further improvement is that the distance between the axially extending front end of the protrusion and the end surface of the stator core is greater than 2 mm.

[0008] A further improved solution is: the first insulating layer is integrally formed and coated on the stator core.

[0009] A further improvement is that the thickness of the second insulating layer is greater than 1 mm.

[0010] A further improvement is that the thickness of the third insulating layer is greater than 1 mm.

[0011] A further improvement is as follows: the distance between the axially extending front end of the protrusion and the end surface of the stator core is 2 mm, the thickness of the second insulating layer is 1 mm, and the thickness of the third insulating layer is 1 mm.

[0012] A further improvement is that the stator assembly also includes an outgoing wire connecting the coil and the outside world, and an insulating sleeve is sleeved on the outgoing wire.

[0013] A further improved solution is: the stator assembly further includes a metal ring, the metal ring is press-fitted onto the stator bracket, and the second insulating layer is located between the metal ring and the stator bracket.

[0014] The present application also provides an electric tool, comprising the outer rotor motor as described in any one of the above items.

[0015] Compared with the prior art, the utility model has the following beneficial effects: an outer rotor motor, comprising a stator assembly and a rotor assembly, wherein the rotor assembly is sleeved on the outside of the stator assembly, wherein the stator assembly comprises a stator core, a stator bracket and a coil, wherein the stator core is sleeved on the stator bracket, wherein the coil is wound on the stator core, wherein the rotor assembly comprises a rotor casing and a rotating shaft, wherein the rotating shaft is passed through the rotor casing, wherein the outer rotor motor further comprises an insulating component, wherein the insulating component comprises a first insulating layer coated on the stator core, a second insulating layer located between the stator bracket and the stator core, and a third insulating layer located between the rotating shaft and the rotor casing. The outer rotor motor of the utility model has a multiple insulating structure by providing multiple insulating layers, and can meet the insulation requirements of the outer rotor motor in a high-voltage environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A three-dimensional diagram of an outer rotor motor provided in one embodiment of the present application;

[0017] Figure 2 for Figure 1 An exploded view of the outer rotor motor shown;

[0018] Figure 3 A partial cross-sectional view of a stator assembly provided in one embodiment of the present application;

[0019] Figure 4 Another partial cross-sectional view of a stator assembly provided in one embodiment of the present application;

[0020] Figure 5 A cross-sectional view of a rotor assembly provided in one embodiment of the present application;

[0021] Figure 6 A three-dimensional diagram of an electric tool provided in accordance with an embodiment of the present application.

[0022] Meaning of the reference numerals in the figures:

[0023] Stator assembly 100 Stator core 110

[0024] Stator support 120 Coil 130

[0025] Metal ring 140 Rotor assembly 200

[0026] Rotor housing 210 Rotating shaft 220

[0027] Insulation component 300 First insulation layer 310

[0028] Main insulating portion 311 Protruding portion 312

[0029] Second insulating layer 320 Third insulating layer 330

[0030] Power tools1 External rotor motor2 DETAILED DESCRIPTION

[0031] The utility model is further described in detail below in conjunction with the accompanying drawings and implementation modes.

[0032] The terms used in the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. For example, the following words such as "upper", "lower", "front", "back", etc. indicating orientation or positional relationship are only based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device / element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. The "including" mentioned in the specification and claims is an open term, so it should be interpreted as "including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and basically achieve the technical effect. In addition, in the embodiments of the present application, multiple refers to two or more. In the absence of mutual contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0033] Figure 1 A three-dimensional diagram of an outer rotor motor provided in one embodiment of the present application; Figure 2 for Figure 1 An exploded view of the outer rotor motor shown; Figure 3 A partial cross-sectional view of a stator assembly provided in one embodiment of the present application; Figure 4 Another partial cross-sectional view of a stator assembly provided in one embodiment of the present application; Figure 5 A cross-sectional view of a rotor assembly provided in one embodiment of the present application; Figure 6A three-dimensional diagram of an electric tool provided in accordance with an embodiment of the present application.

[0034] Please refer to Figures 1 to 5 , an outer rotor motor, used for outputting torque to the outside after being energized, comprising a stator assembly 100 and a rotor assembly 200. The rotor assembly 200 is sleeved on the outside of the stator assembly 100, and can be fixed to each other afterwards. It can be understood that, although not shown in the drawings of this embodiment, the outer rotor motor may further include a motor housing, and the motor housing is used to accommodate and protect the stator assembly 100 and the rotor assembly 200. Among them, the stator assembly 100 includes a stator core 110, a stator bracket 120 and a coil 130, the stator core 110 is sleeved on the stator bracket 120, and the coil 130 is wound on the stator core 110. In addition, the rotor assembly 200 includes a rotor casing 210 and a rotating shaft 220, the rotating shaft 220 is penetrated in the rotor casing 210, and the rotating shaft 220 is fixed to the rotor casing 210. A plurality of magnets are fixed on the inner wall of the rotor housing 210, and the magnets are arranged at intervals in a circumference. When the outer rotor motor is powered on, the rotor housing 210 rotates and drives the rotating shaft 220 to rotate, outputting torque to the outside.

[0035] In order to make the outer rotor motor have a stronger insulation capacity so that it can cope with the high voltage environment, the outer rotor motor also includes an insulation component 300. The insulation component 300 is arranged in the outer rotor motor, and can provide additional insulation capacity between the components in the outer rotor motor. Among them, the insulation component 300 includes at least three insulation layers, and the plurality of insulation layers are combined to act on the outer rotor motor, so that the outer rotor motor has stronger insulation performance after power is turned on. Specifically, the insulation component 300 includes a first insulation layer 310 coated on the stator core 110, a second insulation layer 320 located between the stator bracket 120 and the stator core 110, and a third insulation layer 330 located between the rotating shaft 220 and the rotor housing 210. In this embodiment, the surface of the coil 130 has at least one insulation layer, for example, the coil 130 is an enameled wire. The outer rotor motor of the utility model has a multiple insulation structure by setting multiple insulation layers. The multiple insulation structure is relatively single or at most double insulation structure, which can better meet the insulation requirements of the outer rotor motor in a high voltage environment.

[0036] In one embodiment, the first insulating layer 310 includes a main insulating portion 311 and a protrusion 312 connected to the main insulating portion 311. The first insulating layer 310 is integrally injection molded around the stator core 110, and the notch of the stator core 110 is integrally wrapped with insulating material. The coil 130 is wound on the stator core 110 across the main insulating portion 311, and the protrusion 312 extends axially from one end face of the stator core 110. It should be noted that the axial direction is the axial direction of the rotating shaft 220. In this embodiment, the protrusion 312 is annular and erected at one end of the stator core 110. The inner side of the stator core 110 is hollow and cylindrical, through which the rotating shaft 220 can pass. The cylindrical wall surface inside the stator core 110 is not covered with insulating material. By providing the protrusion 312 covered with the first insulating layer 310, the creepage distance from the coil 130 to the uncovered insulating portion of the stator core 110 is increased. It should be noted that the creepage distance refers to the shortest path between two conductive parts or between a conductive part and the protective interface of the equipment measured along the surface of the insulating material. By providing the protrusion 312, the creepage distance from the coil 130 to the stator core 110 must pass through and calculate the height of the protrusion 312, thereby extending the creepage distance and enhancing the insulation capacity of the outer rotor motor.

[0037] The first insulating layer 310 may completely cover the protrusion 312, or may cover part of the protrusion 312. The protrusion 312 is annular, including an inner wall surface and an outer wall surface. When the first insulating layer 310 covers part of the protrusion 312, the first insulating layer 310 at least covers the outer wall surface of the protrusion 312.

[0038] In one embodiment, the distance between the front end of the axial extension of the protrusion 312 and the end face of the stator core 110 is greater than 2 mm, that is, the height of the protrusion 312 is greater than 2 mm. The coil 130 to the stator core 110 can only pass through the protrusion 312, and the protrusion 312 is covered with the first insulating layer 310, so when the protrusion 312 is higher than 2 mm, the corresponding creepage distance is at least greater than 2 mm. By setting the protrusion 312 higher than 2 mm, the creepage distance from the coil 130 to the stator core 110 must pass through and calculate the height of the protrusion 312, thereby extending the creepage distance by at least 2 mm and enhancing the insulation capacity of the outer rotor motor.

[0039] In one embodiment, the first insulating layer 310 is integrally formed and coated on the stator core 110. The integrally formed first insulating layer 310 ensures that the insulation between the protrusion 312 and the main insulating portion 311 is more stringent, and does not cause the actual creepage distance to be less than the theoretical creepage distance, and the actual insulation performance of the outer rotor motor is weaker than the theoretical insulation performance. For example, when a protrusion 312 with a height greater than 2 mm is provided, the theoretical creepage distance is at least greater than 2 mm, and the actual creepage distance can be ensured to be at least greater than 2 mm only when and only when there is no non-insulating part between the protrusion 312 and the main insulating portion 311.

[0040] The thicker the insulation layer, the better the insulation effect. In one embodiment, the thickness of the second insulation layer 320 is greater than 1 mm. In another embodiment, the thickness of the third insulation layer 330 is greater than 1 mm. Preferably, in order to enable the outer rotor motor to have high-voltage operation capability, that is, its insulation assembly 300 has the insulation capability of a high-voltage environment, the axially extending front end of the protrusion 312 is 2 mm away from the end face of the stator core 110, the thickness of the second insulation layer 320 is 1 mm, and the thickness of the third insulation layer 330 is 1 mm.

[0041] To further enhance the insulation capability, in one embodiment, the stator assembly 100 further includes an outlet wire connecting the coil 130 and the outside, and an insulating sleeve is sleeved on the outlet wire. Furthermore, the insulating sleeve may be a double-walled tube.

[0042] In one embodiment, the stator assembly 100 further includes a metal ring 140, and the metal ring 140 is pressed onto the stator bracket 120, and the second insulating layer 320 is located between the metal ring 140 and the stator bracket 120. Specifically, when manufacturing the motor, stator winding cannot be performed by injection molding first, and injection molding cannot be performed by winding first, which makes it difficult to add an insulating layer between the stator bracket 120 and the iron core. Therefore, the method of adding an insulating layer between the stator bracket 120 and the iron core is converted into a method of adding an insulating layer between the bracket and the metal ring 140. Preferably, the metal ring 140 can be a copper ring or a steel ring.

[0043] Please refer to Figure 6 The utility model also relates to an electric tool 1, comprising the outer rotor motor 2. Preferably, the electric tool is an electric drill, an angle grinder or an electric saw.

[0044] The utility model is not limited to the above specific implementations. Those skilled in the art can easily understand that there are many alternatives to the outer rotor motor and electric tool of the utility model without departing from the principle and scope of the utility model. The protection scope of the utility model shall be based on the content of the claims.

Claims

1. An outer rotor motor, comprising a stator assembly and a rotor assembly, wherein the rotor assembly is sleeved outside the stator assembly, the stator assembly comprises a stator core, a stator bracket and a coil, the stator core is sleeved on the stator bracket, the coil is wound on the stator core, the rotor assembly comprises a rotor housing and a rotating shaft, the rotating shaft is penetrated in the rotor housing, and is characterized in that: The outer rotor motor also includes an insulating assembly, which includes a first insulating layer coated on the stator core, a second insulating layer located between the stator bracket and the stator core, and a third insulating layer located between the rotating shaft and the rotor housing; the first insulating layer includes a main insulating portion and a protrusion connected to the main insulating portion, the coil is wound on the stator core through the main insulating portion, and the protrusion extends axially from one side end surface of the stator core.

2. The outer rotor motor according to claim 1, characterized in that: The distance between the axially extending front end of the protrusion and the end surface of the stator core is greater than 2 mm.

3. The outer rotor motor according to claim 1, characterized in that: The first insulating layer is integrally formed and covers the stator core.

4. The outer rotor motor according to claim 1, characterized in that: The thickness of the second insulating layer is greater than 1 mm.

5. The outer rotor motor according to claim 1, characterized in that: The thickness of the third insulating layer is greater than 1 mm.

6. The outer rotor motor according to claim 1, characterized in that: The distance between the axially extending front end of the protrusion and the end surface of the stator core is 2 mm, the thickness of the second insulating layer is 1 mm, and the thickness of the third insulating layer is 1 mm.

7. The outer rotor motor according to claim 1, characterized in that: The stator assembly also includes an outgoing wire connecting the coil and the outside, and an insulating sleeve is sleeved on the outgoing wire.

8. The outer rotor motor according to claim 1, characterized in that: The stator assembly also includes a metal ring, which is press-fitted onto the stator bracket, and the second insulating layer is located between the metal ring and the stator bracket.

9. An electric tool, characterized in that: It comprises the outer rotor motor as claimed in any one of claims 1 to 8.

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