Motor

Abstract

The utility model provides a motor, which comprises a casing and a motor body accommodated in the casing, and is characterized in that the motor body comprises a stator assembly and a rotor assembly rotating around the axis of the stator assembly; the stator assembly is arranged in the casing, the casing is provided with a plurality of air inlet windows, the air inlet windows are positioned at the axial end part of the stator assembly, the position of each air inlet window corresponds to a gap between two adjacent stator coils of the stator assembly, and external airflow enters the stator assembly from the air inlet windows. According to the motor provided by the utility model, the air inlet window is arranged at the position, corresponding to the gap between the two adjacent stator coils of the stator assembly in the casing, on the casing, so that external airflow enters the stator assembly from the air inlet window, and compared with an existing motor, the air flow of the external airflow entering the stator assembly is greatly improved; and the heat dissipation and cooling effects of the motor are greatly improved.

Description

Technical Field

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

[0002] An electric motor is an electromagnetic device that converts or transmits electrical energy based on the law of electromagnetic induction. Electric motors primarily operate based on Ampere's law of force and the law of electromagnetic induction. A current-carrying conductor in a magnetic field experiences an Ampere force. When current flows through the stator windings of an electric motor, a rotating magnetic field is generated. The rotor conductors cut magnetic field lines in this rotating magnetic field, generating an induced electromotive force and an induced current. This, in turn, induces the Ampere force, causing the rotor to rotate and thus converting electrical energy into mechanical energy.

[0003] Motors typically dissipate heat through cooling fans, which are usually mounted on the axial end of the motor shaft that runs through the housing. However, in existing motors, because the cooling fan is located outside the housing, the airflow blowing into the motor through the fan is reduced by the housing's ribs; furthermore, some of the airflow blowing into the motor is blocked by the stator coils, significantly impacting the motor's heat dissipation and cooling efficiency.

[0004] In view of this, it is indeed necessary to provide a technical solution to the above problems. Summary of the Invention

[0005] The main purpose of this invention is to provide a motor that improves the heat dissipation and cooling effect of the motor.

[0006] To achieve the above objectives, this utility model provides a motor, comprising:

[0007] A housing and a motor body housed within the housing, the motor body including a stator assembly and a rotor assembly that rotates about the axis of the stator assembly;

[0008] The housing is provided with multiple air inlets, which are located at the axial end of the stator assembly. The position of each air inlet corresponds to the gap between two adjacent stator coils of the stator assembly, and external airflow enters the stator assembly through the air inlets.

[0009] In some embodiments, the air inlet window extends axially through the housing, and the cross-sectional area of ​​the air inlet window facing the stator assembly is smaller than the cross-sectional area of ​​the air inlet window away from the stator assembly.

[0010] In some embodiments, the radial shape of the air inlet window is an isosceles trapezoidal structure, with the short side of the isosceles trapezoidal structure close to the axis of the motor body and the long side of the isosceles trapezoidal structure far from the axis of the motor body.

[0011] In some embodiments, the radial cross-sectional area of ​​the air inlet window gradually decreases from the outside to the inside along the axial direction of the motor body; the wall surface formed by the air inlet window in the housing is a smooth surface with a smooth transition.

[0012] In some embodiments, the rotor assembly includes a rotor and a motor shaft fixed to the rotor, and the motor body includes a cooling fan located between the stator assembly and the air inlet and fixed to the motor shaft, the cooling fan introducing external airflow into the stator assembly from the air inlet.

[0013] In some embodiments, the air inlets are evenly distributed circumferentially around the motor shaft, and the number of air inlets is the same as the number of stator coils in the stator assembly.

[0014] In some embodiments, the motor body includes a shroud connected to the end of the housing, the shroud being located at the axial rear end of the air inlet.

[0015] In some embodiments, the air deflector has a horn-shaped structure, and the inner diameter of the cross section of the air deflector near the air inlet window is smaller than the inner diameter of the cross section of the air deflector away from the air inlet window.

[0016] In some embodiments, the radial cross-sectional area of ​​the flow guide gradually decreases from the outside to the inside along the axial direction of the motor body and transitions smoothly, and the flow guide is integrally injection molded.

[0017] In some embodiments, the axial length of the fairing ranges from 1 cm to 3 cm.

[0018] The beneficial effects of this utility model are as follows: The motor provided by this utility model, by setting an air inlet window on the housing corresponding to the gap between two adjacent stator coils of the stator assembly inside the housing, allows external airflow to enter the stator assembly through the air inlet window. Compared with existing motors, this greatly increases the airflow rate of external air into the stator assembly, thereby greatly improving the heat dissipation and cooling effect of the motor. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the present invention and, together with the description, serve to explain the principles of the present invention.

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] 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.

[0022] Figure 1 A cross-sectional view of the motor provided in an embodiment of this utility model;

[0023] Figure 2 for Figure 1 A three-dimensional schematic diagram of the motor shown;

[0024] Figure 3 for Figure 2 A three-dimensional schematic diagram of part of the motor structure shown;

[0025] Figure 4 for Figure 2 A three-dimensional schematic diagram of the motor from another angle.

[0026] Explanation of reference numerals in the accompanying drawings of this utility model:

[0027] Motor body 10, rotor assembly 11, stator assembly 12, housing 20, air inlet 21, wall surface 211, air guide 22, motor shaft 30, clearance 40, cooling fan 50.

[0028] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0030] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0031] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0032] This utility model embodiment provides a motor, see [link]. Figure 1 , Figure 2 ,as well as Figure 3 The motor includes: a housing 20, a motor body 10 housed in the housing, and a cooling fan 50 mounted on the motor body 10. The housing has an air inlet (not shown) and an air outlet (not shown), which are located at opposite ends of the axial direction of the motor body. The motor body 10 includes a stator assembly 12 and a rotor assembly 11 that rotates around the axis of the stator assembly 12. The cooling fan 50 draws in external air through the air inlet, flows through the stator assembly 12, and then discharges it through the air outlet. The housing 20 has multiple air inlets 21, which are located at the axial ends of the stator assembly 12 and are located on the same side as the air inlet. The position of each air inlet 21 corresponds to the gap 40 between two adjacent stator coils of the stator assembly 12. External airflow enters the stator assembly 12 through the air inlet and then exits through the air outlet.

[0033] The motor provided in this embodiment has a motor shaft 30 that passes through the housing 20. A cooling fan 50 for cooling the motor body 10 is mounted on the motor shaft 30 and located axially outside the air inlet 21, corresponding to the position of the plurality of air inlets 21. During operation, the cooling fan 50 draws external airflow (air) into the stator assembly 12 through the plurality of air inlets 21. Since the position of each air inlet 21 corresponds to the gap 40 between two adjacent stator coils of the stator assembly 12, this arrangement can reduce the loss of airflow (air) entering the stator assembly 12 through each air inlet 21. Compared with existing motors, this greatly increases the airflow rate of external air into the stator assembly, thereby greatly improving the heat dissipation and cooling effect of the motor.

[0034] In some embodiments, see Figure 3The air inlet 21 extends axially through the housing 20. The cross-sectional area of ​​the air inlet 21 facing the stator assembly 12 is smaller than the cross-sectional area of ​​the air inlet 21 away from the stator assembly 12. That is, the area of ​​the air inlet of the air inlet 21 is larger than the area of ​​the air outlet. According to the fluid continuity equation, ideally, when fluid flows through the air inlet 21, the volume of fluid passing through different cross-sections per unit time is equal, i.e., Q = A × v (Q is the flow rate, A is the cross-sectional area of ​​the air inlet 21, and v is the fluid velocity). Because the air inlet area is large and the air outlet area is small, when the airflow rate Q is constant, the cross-sectional area A of the air outlet decreases, and the airflow velocity v increases. Therefore, the above-mentioned arrangement of the air inlet 21 allows the airflow velocity entering the air inlet 21 to gradually increase, thereby further improving the heat dissipation and cooling effect of the motor.

[0035] In some embodiments, see Figure 3 The air inlet 21 has a radial shape of an isosceles trapezoid, with the shorter side of the trapezoid closer to the axis of the motor body 10 and the longer side further away from the axis of the motor body 10. This arrangement ensures that the shape of the air inlet 21 matches the shape of the gap 40 between two adjacent stator coils of the stator assembly 12, thereby reducing airflow loss into the stator assembly 12 and improving the motor's heat dissipation and cooling effect.

[0036] In some embodiments, see Figure 2 and Figure 3 The radial cross-sectional area of ​​the air inlet 21 gradually decreases from the outside to the inside along the axial direction of the motor body 10; the wall surface 211 formed by the air inlet 21 in the housing 20 is a smooth surface with a smooth transition. The wall surface 211 is set as a smooth surface with a smooth transition, which can effectively reduce the airflow loss entering the air inlet 21.

[0037] In some embodiments, see Figure 1 The rotor assembly 11 includes a rotor and a motor shaft 30 fixed to the rotor. The motor body 10 includes a cooling fan 50 located between the stator assembly 12 and the air inlet 21 and fixed to the motor shaft 30. The cooling fan introduces external airflow into the stator assembly 12 from the air inlet 21.

[0038] In some embodiments, see Figure 3 The air inlets 21 are evenly distributed around the circumference of the motor shaft 30, and the number of air inlets 21 is the same as the number of stator coils in the stator assembly 12. That is, an air inlet 21 is provided for each adjacent stator coil gap 40.

[0039] In some embodiments, see Figure 2 and Figure 4The motor body 10 includes a shroud 22 connected to the end of the housing 20, and the shroud 22 is located at the axial rear end of the air inlet 21. The shroud 22 has a trumpet-shaped structure, and the inner diameter of the cross-section of the shroud 22 near the air inlet 21 is smaller than the inner diameter of the cross-section of the shroud 22 away from the air inlet 21. In this embodiment, the shroud 22 with a trumpet-shaped structure is provided at the axial rear end of the air inlet 21. Setting the inner diameter of the shroud 22 near the air inlet 21 to be smaller than the inner diameter of the cross-section of the shroud 22 away from the air inlet 21 can increase the air inlet area of ​​the shroud 22, and the airflow velocity entering the shroud 22 will gradually increase, thereby further improving the heat dissipation and cooling effect of the motor.

[0040] In some embodiments, see Figure 2 The radial cross-sectional area of ​​the air guide 22 gradually decreases and smoothly transitions from the outside to the inside along the axial direction of the motor 10 body, and the air guide 22 is integrally injection molded. In this embodiment, the radial cross-sectional area of ​​the air guide 22 smoothly transitions from the outside to the inside along the axial direction of the motor 10 body, which can effectively reduce airflow loss entering the air guide 22.

[0041] In some embodiments, the axial length of the flow deflector 22 ranges from 1 cm to 3 cm.

[0042] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0043] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Since these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

[0044] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. An electric motor, characterized in that, The motor includes: The device includes a housing, a motor body housed within the housing, and a cooling fan mounted on the motor body. The motor body includes a stator assembly and a rotor assembly that rotates about the axis of the stator assembly. The housing is provided with an air inlet and an air outlet. The cooling fan draws in outside air through the air inlet, flows through the stator assembly, and discharges it from the air outlet. The air inlet and the air outlet are located at opposite ends of the axial direction of the motor body. The housing is provided with a through air inlet window, which is located at the axial end of the stator assembly. The air inlet is located on the same side as the air inlet window. The position of each air inlet window corresponds to the gap between two adjacent stator coils of the stator assembly. External airflow enters the stator assembly through the air inlet window.

2. The motor according to claim 1, characterized in that, The air inlet window extends axially through the housing, and the cross-sectional area of ​​the air inlet window facing the stator assembly is smaller than the cross-sectional area of ​​the air inlet window away from the stator assembly.

3. The motor according to claim 2, characterized in that, The radial shape of the air inlet window is an isosceles trapezoidal structure, with the short side of the isosceles trapezoidal structure close to the axis of the motor body and the long side of the isosceles trapezoidal structure far away from the axis of the motor body.

4. The motor according to claim 3, characterized in that, The radial cross-sectional area of ​​the air inlet window gradually decreases from the outside to the inside along the axial direction of the motor body; the wall surface formed by the air inlet window in the housing is a smooth surface with a smooth transition.

5. The motor according to claim 1, characterized in that, The rotor assembly includes a rotor and a motor shaft fixed to the rotor. The cooling fan is fixed to the motor shaft and is located at the axial outer end of the air inlet window. The cooling fan introduces external airflow into the stator assembly through the air inlet window.

6. The motor according to claim 5, characterized in that, The air inlets are evenly distributed around the circumference of the motor shaft, and the number of air inlets is the same as the number of stator coils in the stator assembly.

7. The motor according to claim 5, characterized in that, The motor body includes a shroud connected to the end of the housing, the shroud being located at the axial rear end of the air inlet window.

8. The motor according to claim 7, characterized in that, The air deflector has a horn-shaped structure, and the inner diameter of the cross section of the air deflector near the air inlet window is smaller than the inner diameter of the cross section of the air deflector away from the air inlet window.

9. The motor according to claim 8, characterized in that, The radial cross-sectional area of ​​the flow guide gradually decreases from the outside to the inside along the axial direction of the motor body and transitions smoothly. The flow guide is integrally injection molded.

10. The motor according to claim 9, characterized in that, The axial length of the fairing ranges from 1 cm to 3 cm.

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