Electric tool

Abstract

The utility model provides an electric tool which comprises a shell, a motor and an air guide support, the shell is cylindrical, and an air inlet is formed in one end of the shell; the motor comprises a stator, a rotor and a rotor shaft, the stator is sleeved between the rotor and the shell, and a stator-rotor gap is formed between the stator and the rotor; the air guide support is arranged in the shell and close to the air inlet, the air guide support comprises a cover-shaped air gathering part, the air gathering part is arranged on the side, close to the air inlet, of the stator corresponding to the stator-rotor gap, and the air gathering part is arranged in a gradually shrinking mode in the direction from the air inlet to the stator-rotor gap. Cooling air entering the shell from the air inlet is guided into the gap between the stator and the rotor through the air gathering part. According to the electric tool, the air guide support is arranged at the air inlet, the gathering effect on the cooling air can be achieved through the air gathering portion of the air guide support, the air gathering portion can gather the cooling air entering from the air inlet to completely pass through the gap between the stator and the rotor, and therefore the air volume between the stator and the rotor is increased, and the heat dissipation efficiency of the motor is improved.

Description

Technical Field

[0001] The embodiments of the present utility model relate to the technical field of power tools, and particularly to a power tool. Background Art

[0002] Power tools such as trimming machines are machines for grooving, trimming, etc. at high speeds. During operation, they need to be comfortably held, not numb the hand, and the holding part does not get hot during long-term operation and has a good cooling system. The existing power tools adopt a double-shell structure of an internal resin material shell + an external metal shell to ensure the coaxiality of the motor, insulation, and no deformation during multiple smooth frictions with the base. The rear bearing of the motor rotor is positioned on the semi-plastic inner shell. Long-term operation and placement in the natural environment cause the inner shell to deform, resulting in low coaxiality of the motor positioning or friction between the rotor and the stator, burning out the motor. At the same time, the gap between the stator and the inner shell allows the cooling air flow to pass through, reducing the air volume between the stator and the rotor, so that the heat generated by the motor cannot be taken out in time, resulting in the heating of the shell at the holding part and reducing the user experience. Content of the Utility Model

[0003] The purpose of the embodiments of the present utility model is to provide a power tool, aiming to improve the heat dissipation problem between the motor and the shell of the existing power tool.

[0004] To solve the above technical problems, the embodiments of the present utility model provide a power tool, including:

[0005] A shell, the shell is arranged in a cylindrical shape, and an air inlet is arranged at one end of the shell;

[0006] A motor, the motor includes a stator, a rotor, and a rotor shaft. The rotor shaft is rotatably arranged in the shell. The rotor is sleeved on the rotor shaft, the stator is sleeved between the rotor and the shell, and a stator-rotor gap is formed between the stator and the rotor;

[0007] A wind guiding bracket, the wind guiding bracket is arranged in the shell and near the air inlet. The wind guiding bracket includes a wind-gathering part in a shape of a cover. The wind-gathering part is correspondingly arranged on the side of the stator close to the air inlet with respect to the stator-rotor gap. The wind-gathering part is gradually contracted in the direction from the air inlet to the stator-rotor gap, so as to guide the cooling air entering the shell from the air inlet into the stator-rotor gap through the wind-gathering part.

[0008] The power tool of the present utility model is provided with a wind guiding bracket at the air inlet. The wind-gathering effect of the cooling air can be achieved through the wind-gathering part of the wind guiding bracket. The wind-gathering part can gather the cooling air entering from the air inlet to completely pass through the stator-rotor gap, thereby increasing the air volume between the stator and the rotor and improving the heat dissipation efficiency of the motor.

[0009] Preferably, the inner side surface of the wind gathering part is an arc surface.

[0010] Preferably, the inner diameter of the end of the wind gathering part close to the stator is larger than the inner diameter of the stator.

[0011] Preferably, the air guiding bracket includes a supporting part, the supporting part is located inside the end of the wind gathering part close to the stator, an installation groove is arranged on the supporting part, and one end of the rotor shaft close to the air inlet can be rotatably arranged in the installation groove.

[0012] Preferably, a plurality of supporting ribs are connected between the wind gathering part and the supporting part, and the supporting ribs are arranged at intervals along the circumferential direction of the wind gathering part.

[0013] Preferably, one end of the rotor shaft close to the air inlet is arranged in the installation groove through a bearing.

[0014] Preferably, the housing includes an inner housing, an outer housing and a top housing, the inner housing is sleeved between the stator and the outer housing, one end of the outer housing is sleeved outside one end of the top housing, and the air inlet is arranged on the top housing; an annular boss extending along the circumferential direction of the wind gathering part is convexly arranged on the outer side wall of the wind gathering part, and the annular boss abuts between the end faces of the inner housing and the top housing close to each other.

[0015] Preferably, a first abutting protrusion is convexly arranged on the circumferential side surface of the annular boss, a second abutting protrusion abuting against the first abutting protrusion is convexly arranged on the inner wall of the outer housing, and a plurality of the second abutting protrusions and the first abutting protrusions are arranged at intervals and correspond to each other one by one along the circumferential direction of the wind gathering part.

[0016] Preferably, one end of the wind gathering part far from the air inlet extends into the inner housing, a third abutting protrusion is convexly arranged on the outer side surface of the end of the wind gathering part far from the air inlet, a fourth abutting protrusion abuting against the third abutting protrusion is convexly arranged on the inner wall of the inner housing, and a plurality of the third abutting protrusions and the fourth abutting protrusions are arranged at intervals and correspond to each other one by one along the circumferential direction of the wind gathering part.

[0017] Preferably, a first clamping groove extending along the circumferential direction of the wind gathering part is arranged on the outer side surface of the end of the wind gathering part extending into the top housing, a positioning rib clamped and matched with the first clamping groove is convexly arranged on the inner wall of the top housing, and the positioning rib extends along the circumferential direction of the wind gathering part.

[0018] Preferably, a plurality of the first card slots and the positioning ribs are arranged in a one-to-one correspondence and at intervals along the circumferential direction of the air gathering part, an anti-rotation rib is formed between two adjacent first card slots, and a second card slot that is in snap-fit with the anti-rotation rib is formed between two adjacent positioning ribs.

[0019] Preferably, an annular support surface extending along the circumferential direction of the stator is provided on the inner wall of the inner housing, and the annular support surface abuts against the side of the stator away from the air inlet. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0021] Figure 1 is a cross-sectional view of the power tool in an embodiment of the present invention;

[0022] Figure 2 is Figure 1 an exploded view of the power tool in;

[0023] Figure 3 is Figure 1 an exploded view of the top housing and the air guide bracket in;

[0024] Figure 4 is Figure 3 a schematic structural view of the air guide bracket in;

[0025] Figure 5 is Figure 4 a schematic structural view of the air guide bracket from another perspective in;

[0026] Figure 6 is Figure 4 a cross-sectional view of the air guide bracket in.

[0027] Description of the reference numerals in the drawings of the present invention:

[0028] Power tool 100, housing 1, inner housing 11, outer housing 12, top housing 13, positioning rib 14, second card slot 15, annular support surface 16, left housing 17, right housing 18, motor 2, stator 21, rotor 22, rotor shaft 23, stator-rotor gap 24, axial flow fan 25, air guide bracket 3, air gathering part 31, support part 32, installation groove 33, support rib 34, annular boss 35, first abutting projection 36, third abutting projection 37, first card slot 38, anti-rotation rib 39, bearing 4.

[0029] The realization, functional features and advantages of the object of the present invention will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation mode

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

[0031] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present utility model, the directional indications are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0032] In addition, if there are descriptions such as "first" and "second" involved in the embodiments of the present utility model, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present utility model.

[0033] The present utility model provides a power tool, which can be a trimming machine, etc. The following will take the power tool as a trimming machine as an example for introduction. Figures 1 to 6 Fig. shows a preferred embodiment of the power tool provided by the present utility model.

[0034] Please refer to Figure 1 and Figure 2 In this embodiment, the power tool 100 includes a housing 1, a motor 2, and a wind guide bracket 3.

[0035] Please refer to Figure 1 and Figure 2 The housing 1 is arranged in a cylindrical shape, and an air inlet (not shown in the figure) is provided at one end of the housing 1.

[0036] Specifically, the housing 1 is usually arranged in a cylindrical shape. Here, the extension direction of the housing 1 is defined as the up-down direction, and the end of the housing 1 provided with the air inlet is the upper end of the housing 1. The specific style of the housing 1 can be set according to the actual situation. Optionally, please refer to Figures 1 to 3, in this embodiment, the housing 1 includes an inner housing 11, an outer housing 12 and a top housing 13. The inner housing 11 is sleeved inside the outer housing 12. One end of the outer housing 12 is sleeved outside one end of the top housing 13. An air inlet is provided on the top housing 13.

[0037] Specifically, the lower end of the outer housing 12 is sleeved outside the inner housing 11, the upper end of the outer housing 12 is sleeved outside the lower end of the top housing 13. The air inlet is provided at the upper end of the top housing 13. And the top housing 13 is generally used for installing the battery of the power tool 100, that is, the top housing 13 can be a battery holder.

[0038] Please refer to Figure 1 and Figure 2 , the motor 2 includes a stator 21, a rotor 22 and a rotor shaft 23. The rotor shaft 23 is rotatably arranged inside the housing 1. The rotor 22 is sleeved on the rotor shaft 23. The stator 21 is sleeved between the rotor 22 and the housing 1. A stator-rotor gap 24 is formed between the stator 21 and the rotor 22.

[0039] Specifically, the motor 2 is arranged inside the housing 1. The rotor shaft 23 extends along the vertical direction. The lower end of the rotor shaft 23 is rotatably arranged on the housing 1 along the vertical axis. And an axial flow fan 25 is provided at the lower end of the rotor shaft 23. The axial flow fan 25 can be driven to rotate by the rotor shaft 23.

[0040] The rotor 22 is sleeved outside the middle part of the rotor shaft 23. The stator 21 is sleeved outside the rotor 22. The stator 21 is fixedly sleeved inside the housing 1. For example, please refer to Figures 1 to 3 , in this embodiment, the stator 21 is fixedly sleeved inside the inner housing 11. And since the inner diameter of the stator 21 is larger than the outer diameter of the rotor 22, a stator-rotor gap 24 is formed between the stator 21 and the rotor 22.

[0041] Please refer to Figures 1 to 3 , the air guide bracket 3 is arranged inside the housing 1 and near the air inlet. The air guide bracket 3 includes a hood-shaped air gathering part 31. The air gathering part 31 is arranged on the side of the stator 21 close to the air inlet corresponding to the stator-rotor gap 24. The air gathering part 31 is gradually contracted in the direction from the air inlet to the stator-rotor gap 24, so as to guide the cooling air entering the housing 1 from the air inlet into the stator-rotor gap 24 through the air gathering part 31.

[0042] Specifically, the air guide bracket 3 is fixedly arranged in the upper end of the housing 1, and the air guide bracket 3 is close to the air inlet. The air guide bracket 3 includes an air gathering portion 31 with upper and lower openings, the upper opening of the air gathering portion 31 faces the air inlet, and the lower opening of the air gathering portion 31 faces the rotor gap 24. The cross-sectional shape of the air gathering portion 31 is usually circular, and the inner diameter of the air gathering portion 31 is gradually reduced from top to bottom, so that the air gathering portion 31 has a gathering effect on the cooling air, so that the air gathering portion 31 can gather the cooling air entering from the air inlet to completely pass through the stator-rotor gap 24, thereby increasing the air volume between the stator 21 and the rotor 22, and improving the heat dissipation efficiency of the motor 2.

[0043] The wind collecting portion 31 is gradually contracted from top to bottom, and the specific shape of the wind collecting portion 31 can be set in a variety of ways. For example, the wind collecting portion 31 can be set in a truncated cone shape. Figure 1 , Figure 5 and Figure 6 In this embodiment, the inner side surface of the wind collecting portion 31 is a curved surface, and the inner side surface of the wind collecting portion 31 is a curved surface such as a circular arc surface.

[0044] Optionally, see Figure 1 and Figure 6 In this embodiment, the inner diameter of the end of the wind collecting portion 31 close to the stator 21 is larger than the inner diameter of the stator 21. Such a configuration is conducive to the cooling wind collected by the wind collecting portion 31 to completely pass through the stator-rotor gap 24.

[0045] Likewise, see Figure 1 In this embodiment, an annular support surface 16 extending along the circumference of the stator 21 is provided on the inner shell wall of the inner shell 11, and the annular support surface 16 abuts against a side of the stator 21 away from the air inlet.

[0046] Specifically, an upward annular support surface 16 is provided on the inner shell wall at the lower end of the inner shell 11, and the annular support surface 16 is located on the lower side of the stator 21. The lower end surface of the inner shell 11 is in contact with the annular support surface 16, so that the air duct between the stator 21 and the inner shell 11 is blocked, so that all cooling air can flow through the stator-rotor gap 24.

[0047] The electric tool 100 of the utility model is provided with an air guide bracket 3 at the air inlet, and the air gathering portion 31 of the air guide bracket 3 can achieve a gathering effect on the cooling air. The air gathering portion 31 can gather the cooling air entering from the air inlet and completely pass through the stator-rotor gap 24, thereby increasing the air volume between the stator 21 and the rotor 22 and improving the heat dissipation efficiency of the motor 2.

[0048] Optionally, see Figure 1 , Figure 4 and Figure 6, in this embodiment, the air guiding bracket 3 includes a supporting part 32. The supporting part 32 is located inside one end of the air collecting part 31 close to the stator 21. An installation groove 33 is arranged on the supporting part 32. One end of the rotor shaft 23 close to the air inlet is rotatably arranged in the installation groove 33.

[0049] Specifically, the supporting part 32 is arranged in a downward cover shape. A circular installation groove 33 is arranged on the supporting part 32. The upper end of the rotor shaft 23 is rotatably arranged in the installation groove 33. The air guiding bracket 3 can support and position the rotor shaft 23 through the supporting part 32. In this way, while the air guiding bracket 3 realizes the positioning of the motor 2, it can also improve the heat dissipation problem between the motor 2 and the housing 1.

[0050] Further, please refer to Figure 1 and Figure 6 , in this embodiment, one end of the rotor shaft 23 close to the air inlet is arranged in the installation groove 33 through a bearing 4. Arranging the bearing 4 in the installation groove 33 is beneficial to realizing the support and positioning of the upper end of the rotor shaft 23.

[0051] Optionally, please refer to Figures 4 to 6 , in this embodiment, a plurality of support ribs 34 are connected between the air collecting part 31 and the supporting part 32. The support ribs 34 are arranged at intervals along the circumferential direction of the air collecting part 31. The air collecting part 31 and the supporting part 32 are connected by a plurality of support ribs 34. A hollow is formed between the plurality of support ribs 34. In this way, the air guiding bracket 3 has a smaller air resistance.

[0052] The air guiding bracket 3 is fixedly arranged inside the upper end of the housing 1. Optionally, please refer to Figures 1 to 3 , in this embodiment, an annular boss 35 extending along the circumferential direction of the air collecting part 31 is convexly arranged on the outer side wall of the air collecting part 31. The annular boss 35 abuts between the end faces of the inner housing 11 and the top housing 13 close to each other.

[0053] Specifically, the upper table surface of the annular boss 35 abuts and fits with the lower end surface of the top housing 13, and the lower table surface of the annular boss 35 abuts and fits with the upper end surface of the inner housing 11, so as to realize the fixed limit of the air guiding bracket 3 in the up and down directions.

[0054] Further, please refer to Figures 1 to 3 , in this embodiment, the annular boss 35 is fixedly arranged on the upper end surface of the inner housing 11 through a screw connection member (not shown in the figure, and the screw connection member can be a screw, etc.), and a plurality of screw connection members are arranged at intervals along the circumferential direction of the annular boss 35.

[0055] Optionally, please refer to Figures 3 to 5, in this embodiment, a first abutting protrusion 36 protrudes from the circumferential side surface of the annular boss 35, and a second abutting protrusion (not shown in the figure) that abuts against the first abutting protrusion 36 protrudes from the inner wall of the outer housing 12. The second abutting protrusions and the first abutting protrusions 36 are arranged in a one-to-one correspondence and at intervals along the circumferential direction of the air gathering portion 31.

[0056] Specifically, the annular boss 35 is located inside the upper end of the outer housing 12. A plurality of first abutting protrusions 36 protrude from the circumferential side surface of the annular boss 35, and a plurality of second abutting protrusions corresponding to the plurality of first abutting protrusions 36 protrude from the inner wall of the upper end of the outer housing 12. Through the cooperation of the plurality of first abutting protrusions 36 and the plurality of second abutting protrusions, the guide air bracket 3 can be prevented from loosening in the radial direction.

[0057] Similarly, please refer to Figures 3 to 5 , in this embodiment, the end of the air gathering portion 31 away from the air inlet extends into the inner housing 11. A third abutting protrusion 37 protrudes from the outer side surface of the end of the air gathering portion 31 away from the air inlet, and a fourth abutting protrusion that abuts against the third abutting protrusion 37 protrudes from the inner wall of the inner housing 11. The third abutting protrusions 37 and the fourth abutting protrusions are arranged in a one-to-one correspondence and at intervals along the circumferential direction of the air gathering portion 31.

[0058] Specifically, the lower end of the air gathering portion 31 extends into the inner housing 11. A plurality of third abutting protrusions 37 protrude from the outer side surface of the lower end of the air gathering portion 31, and a plurality of fourth abutting protrusions corresponding to the plurality of third abutting protrusions 37 protrude from the inner wall of the upper end of the inner housing 11. Through the cooperation of the plurality of third abutting protrusions 37 and the plurality of fourth abutting protrusions, the guide air bracket 3 can be prevented from loosening in the radial direction.

[0059] Optionally, please refer to Figures 3 to 5 , in this embodiment, a first card slot 38 extending along the circumferential direction of the air gathering portion 31 is provided on the outer side surface of the end of the air gathering portion 31 extending into the top housing 13, and a positioning rib 14 that is in snap-fit with the first card slot 38 protrudes from the inner wall of the top housing 13. The positioning rib 14 is arranged to extend along the circumferential direction of the air gathering portion 31.

[0060] Optionally, please refer to Figures 3 to 5 , in this embodiment, the first card slots 38 and the positioning ribs 14 are arranged in a one-to-one correspondence and at intervals along the circumferential direction of the air gathering portion 31. An anti-rotation rib 39 is formed between two adjacent first card slots 38, and a second card slot 15 that is in snap-fit with the anti-rotation rib 39 is formed between two adjacent positioning ribs 14.

[0061] Specifically, the first slot 38 is close to the upper surface of the annular boss 35, and the top housing 13 includes a left housing 17 and a right housing 18 spliced ​​together on the left and right sides. The left housing 17 and the right housing 18 are both provided with positioning ribs 14 and second slots 15, and the air guide bracket 3 is provided with a first slot 38 and an anti-rotation rib 39. Through the cooperation between the positioning rib 14 and the first slot 38, and the cooperation between the anti-rotation rib 39 and the second slot 15, the air guide bracket 3 can be prevented from radial shaking, and at the same time, a double housing structure with high coaxiality and good rigidity is formed.

[0062] An independent metal motor positioning structure intermediate bracket (i.e., air guide bracket 3) is added to the inner housing 11. The air guide bracket 3 is used for positioning and supporting the rear bearing of the rotor, and is connected to the battery holder (i.e., the top housing 13) at the same time, and axially positions the motor 2 and the inner housing 11. The air guide bracket 3 is arranged at the air inlet. Under the drive of the axial flow fan 25, the cooling air entering from the air inlet can be gathered to completely pass through the stator-rotor gap 24, and the air duct between the stator 21 and the inner housing 11 is completely blocked to prevent the cooling air from circulating, thereby improving the heat dissipation efficiency of the motor 2.

[0063] The above are only preferred embodiments of the present invention, and do not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the utility model concept, or directly / indirectly used in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An electric tool, characterized in that: include: A shell, the shell is cylindrical, and one end of the shell is provided with an air inlet; A motor, the motor comprising a stator, a rotor and a rotor shaft, the rotor shaft being rotatably disposed in the housing, the rotor being sleeved on the rotor shaft, the stator being sleeved between the rotor and the housing, and a stator-rotor gap being formed between the stator and the rotor; An air guide bracket is arranged in the shell and close to the air inlet, and the air guide bracket includes a hood-shaped air collecting portion. The air collecting portion is arranged on a side of the stator close to the air inlet corresponding to the stator-rotor gap, and the air collecting portion is gradually contracted in the direction from the air inlet to the stator-rotor gap, so as to guide the cooling air entering the shell from the air inlet into the stator-rotor gap through the air collecting portion.

2. The electric tool according to claim 1, characterized in that: The inner side surface of the wind gathering portion is a curved surface; and / or, An inner diameter of an end of the wind concentrating portion close to the stator is larger than an inner diameter of the stator.

3. The electric tool according to claim 1, characterized in that: The air guide bracket includes a support portion, the support portion is located in one end of the wind collecting portion close to the stator, the support portion is provided with a mounting groove, and one end of the rotor shaft close to the air inlet is rotatably arranged in the mounting groove.

4. The electric tool according to claim 3, characterized in that: A supporting rib is connected between the wind collecting portion and the supporting portion, and a plurality of the supporting ribs are arranged at intervals along the circumference of the wind collecting portion; and / or, One end of the rotor shaft close to the air inlet is arranged in the mounting groove through a bearing.

5. The electric tool according to any one of claims 1 to 4, characterized in that: The housing comprises an inner housing, an outer housing and a top housing, the inner housing is sleeved between the stator and the outer housing, one end of the outer housing is sleeved outside one end of the top housing, and the top housing is provided with the air inlet; An annular boss extending along the circumference of the wind gathering portion is convexly provided on the outer side wall of the wind gathering portion, and the annular boss abuts between the end surfaces of the inner casing and the top casing which are close to each other.

6. The electric tool according to claim 5, characterized in that: A first abutment protrusion is protruding on the circumferential side surface of the annular boss, and a second abutment protrusion abutting against the first abutment protrusion is protruding on the inner shell wall of the outer shell. The second abutment protrusion corresponds to the first abutment protrusion one by one along the circumferential direction of the wind gathering part and is arranged in multiple intervals.

7. The electric tool according to claim 5, characterized in that: One end of the wind collecting portion away from the air inlet extends into the inner casing, and a third abutment protrusion is protrudingly provided on the outer surface of the end of the wind collecting portion away from the air inlet, and a fourth abutment protrusion abutting against the third abutment protrusion is protrudingly provided on the inner shell wall of the inner casing, and the third abutment protrusion and the fourth abutment protrusion are arranged one by one and at intervals along the circumference of the wind collecting portion.

8. The electric tool according to claim 5, characterized in that: A first slot extending along the circumference of the wind gathering portion is provided on the outer surface of one end of the wind gathering portion extending into the top casing, and a positioning rib which is engaged with the first slot is protruded from the inner shell wall of the top casing, and the positioning rib is extended along the circumference of the wind gathering portion.

9. The electric tool according to claim 8, characterized in that: The first card slots and the positioning ribs are arranged one by one and at intervals along the circumference of the wind gathering portion, an anti-rotation rib is formed between two adjacent first card slots, and a second card slot engaged with the anti-rotation rib is formed between two adjacent positioning ribs.

10. The electric tool according to claim 5, characterized in that: An annular supporting surface extending along the circumference of the stator is arranged on the inner shell wall of the inner shell, and the annular supporting surface abuts against a side of the stator away from the air inlet.

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