Electric tool

Abstract

The utility model discloses an electric tool which comprises a shell, a motor, an impeller, a front end bearing and an air guide pressing plate, the air guide pressing plate is located between the impeller and the front end bearing in the axial direction of the motor, the air guide pressing plate comprises a pressing plate part and an air guide part, the air guide part surrounds the circumferential direction of the pressing plate part, and the plate face, opposite to the impeller, of the pressing plate part abuts against the front end bearing and a bearing chamber. The pressing plate part and the shell are pressed and fixed through a fastener, the air guide part comprises a plurality of blades used for guiding airflow, and the airflow flows in from the air inlet and flows out from the air outlet after being rectified through the blades. According to the utility model, airflow noise is reduced and the problem of fixing the front end bearing is solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of tool equipment, and in particular relates to an electric tool. Background Art

[0002] In order to facilitate heat dissipation, existing power tools (such as angle grinders) usually have an impeller fixed on the motor output shaft, and air inlets and outlets are set at corresponding positions of the shell. Cooling airflow is generated during the synchronous rotation of the impeller and the motor, and the main flow path of the airflow is to flow in through the air inlet and out of the air outlet.

[0003] Due to the external shape of the shell and the requirements of manufacturing, the inner surface of the shell is uneven, and the airflow collides with the irregular inner surface of the shell, which will generate loud noise.

[0004] The housing is also provided with a bearing chamber for accommodating the front bearing, and the motor output shaft is passed through the front bearing and supported on the housing by the front bearing. In the prior art, a boss is provided on the motor output shaft, and the front bearing is limited in the bearing chamber by mutual abutment with the boss. However, the above boss positioning method is subjected to force on the inner ring of the front bearing and has no limiting effect on the outer ring, resulting in low reliability of the fixing of the front bearing.

[0005] Therefore, it is necessary to improve the prior art to overcome the above defects in the prior art. Utility Model Content

[0006] Therefore, the utility model aims to solve the technical problems in the prior art that the electric tool has high noise and the front end bearing has low fixing reliability.

[0007] In order to solve the above technical problems, the utility model provides an electric tool, comprising:

[0008] A housing is provided with an air inlet and an air outlet;

[0009] A motor, disposed in the housing, comprising an output shaft for outputting rotational power;

[0010] An impeller, fixedly disposed on the driving section of the output shaft, and rotating synchronously with the output shaft to generate a cooling airflow;

[0011] A front end bearing is sleeved on the driving section and is located on a side of the impeller away from the rotor assembly of the motor, and the front end bearing is accommodated in a bearing chamber formed by the housing;

[0012] An air guide pressure plate is located between the impeller and the front end bearing in the axial direction of the motor. The air guide pressure plate includes a pressure plate portion and an air guide portion. The air guide portion surrounds the circumference of the pressure plate portion. The plate surface of the pressure plate portion facing away from the impeller abuts against the front end bearing and the bearing chamber. The pressure plate portion and the casing are pressed and fixed by fasteners. The air guide portion includes a plurality of blades for guiding airflow. The airflow flows in from the air inlet, is rectified by the blades, and then flows out through the air outlet.

[0013] In one embodiment, the pressing plate portion and the air guide portion are made of different materials, the strength of the pressing plate portion is greater than the strength of the air guide portion, and the air guide portion is integrally formed with the pressing plate portion.

[0014] In one embodiment, the air guide portion includes an annular base, the blades extend radially outward from a peripheral side surface of the base, and the base wraps around the peripheral outer edge of the pressure plate portion.

[0015] In one embodiment, a recess is provided at the circumferential outer edge of the pressure plate portion, and the air guide portion includes a chimeric body located in the recess and matching the shape of the recess.

[0016] In one embodiment, the pressing plate portion is made of metal material, the air guide portion is made of plastic, and the pressing plate portion serves as an insert of the air guide portion which is injection molded.

[0017] In one embodiment, in the radial direction of the output shaft, the air guide portion is located outside the fastener.

[0018] In one embodiment, the housing includes a positioning portion connected to the fastener, an end surface of the positioning portion is flush with an end surface of the bearing chamber, and the pressure plate portion is a flat plate, and the pressure plate portion is in abutment contact with both the positioning portion and the end surface of the bearing chamber.

[0019] In one embodiment, the pressure plate portion includes a flange close to the output shaft, the flange surrounds the circumference of the output shaft, the surface of the impeller facing the pressure plate portion is recessed inward to form a groove structure, the flange portion extends into the groove structure, or the flange is opposite to the groove structure.

[0020] In one embodiment, the bottom of the groove structure includes a convex rib, the convex rib and the flange are arranged relatively spaced apart, and the flange and the groove structure form a labyrinth structure.

[0021] In one embodiment, a central plane between two plate-shaped surfaces of the pressure plate portion is coplanar with a central plane of the air guide portion that is perpendicular to the output shaft.

[0022] The technical solution provided by the utility model has the following advantages:

[0023] The electric tool provided by the utility model is provided with an air guide pressure plate, and the blades of the air guide pressure plate are used to rectify the airflow, so that the probability of the airflow colliding with the uneven inner wall of the housing can be reduced, and the noise generated thereby can be reduced; after the air guide pressure plate is fixed to the housing, it is pressed against the front end bearing and the bearing chamber to achieve the fixation of the front end bearing, thereby improving the positioning reliability of the front end bearing. The utility model reduces the airflow noise and solves the problem of fixing the front end bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 A three-dimensional schematic diagram of the main structure of the electric tool provided by an embodiment of the utility model;

[0026] Figure 2 for Figure 1 The main structure of the electric tool is shown as a schematic diagram of the exploded structure;

[0027] Figure 3 for Figure 2 A schematic diagram of the front view of the head H of the electric tool shown;

[0028] Figure 4 for Figure 2 The schematic diagram of the main structure of the wind deflector pressure plate shown;

[0029] Figure 5 A schematic diagram of the structure of the two parts of the wind deflector pressure plate provided in one embodiment of the utility model;

[0030] Figure 6 A schematic diagram of a cross-sectional structure of an electric tool provided by an embodiment of the utility model through an air guide pressure plate;

[0031] Figure 7 A schematic diagram of a cross-sectional structure of an electric tool provided by an embodiment of the utility model passing through the motor axis;

[0032] Figure 8 for Figure 7 An enlarged structural schematic diagram of area a of the cross-sectional structural schematic diagram shown. DETAILED DESCRIPTION

[0033] The technical solution of the utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all of the embodiments. The utility model will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. It should be noted that the embodiments of the utility model and the features in the embodiments can be combined with each other without conflict.

[0034] It should be noted that the terms "first", "second", etc. in the specification and claims of the utility model and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0035] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0036] Power tools generally refer to various mechanical tools equipped with an electric drive device (usually a motor). Compared with traditional hand tools, power tools can improve work efficiency and reduce the physical labor intensity of workers, and are therefore widely used in many fields such as home, industry, and construction. Such as electric drills, angle grinders, electric hammers, grinders, and electric wrenches, etc. As described in the background technology, in the prior art, the heat dissipation structure of power tools has a large airflow noise, and the front end bearing positioning is unreliable.

[0037] In order to solve the above problems, the utility model provides an electric tool, which guides the airflow by setting an air guide pressure plate, reduces the noise caused by the collision of the airflow with the inner wall of the shell, and realizes the reliable positioning of the front end bearing. Figure 1 This is a three-dimensional schematic diagram of the main structure of the electric tool provided by the embodiment of the utility model. Figure 2 for Figure 1 The main structure of the power tool is shown in the schematic diagram of the decomposition structure. Figure 3 for Figure 2 The schematic diagram of the main structure of the head H of the electric tool shown in FIG. Figure 4 for Figure 2 The main structural diagram of the wind deflector pressure plate shown. Figure 1 and Figure 2 The electric tool shown is an angle grinder. This embodiment is described by taking the angle grinder as an example, but this should not be construed as a limitation to the present invention.

[0038] See also Figures 1 to 4 The electric tool includes a housing 10 , a motor 20 , an impeller 30 , a front end bearing 40 and an air guide pressure plate 50 .

[0039] The housing 10 forms the outer shell of the electric tool, and the motor 20 and the impeller 30 are both disposed in the housing 10. The housing 10 is provided with an air inlet (not shown) and an air outlet 12, and the impeller 30 is driven to rotate by the motor 20. During the rotation of the impeller 30, an air flow is driven to flow from the air inlet to the air outlet 12, and the air flow flows through the motor 20 to achieve heat dissipation of the motor 20.

[0040] The motor 20 includes an output shaft 24 for outputting rotational power, and the impeller 30 is fixedly arranged on the output shaft 24 and rotates synchronously with the output shaft 24. Specifically, the motor 20 also includes a rotor assembly 21 and a stator assembly 23. The output shaft 24 is inserted into the rotor assembly 21 and rotates synchronously with the rotor assembly 21. The two ends of the output shaft 24 extend out of the rotor assembly 21 respectively, one of which is mainly used to output rotational power, defined as a driving section, and the other end is used to support and position the motor, defined as a positioning section. The driving section and the positioning section are both supported and positioned on the housing 10 by bearings, and the impeller 30 is fixedly arranged on the driving section of the output shaft.

[0041] The driving section of the output shaft 24 is supported and positioned on the housing 10 by the front bearing 40. The front bearing 40 is sleeved on the driving section and is located on the side of the impeller 30 away from the rotor assembly 21 of the motor 20. The front bearing 40 is accommodated in the bearing chamber 132 formed in the housing 10. The driving section extends into the front bearing 40 and is supported on the housing 10 by the front bearing 40. The rear bearing 42 is sleeved on the positioning section of the output shaft 24. The rear bearing 42 is accommodated in the rear bearing chamber (not shown) formed in the housing 10. The positioning section extends into the rear bearing 42 and is supported on the housing 10 by the rear bearing 42. The driving section and the positioning section of the output shaft 24 are supported and positioned on the housing 10 by the front bearing 40 and the rear bearing 42, respectively, so as to realize the support and positioning of the motor 20 relative to the housing 10.

[0042] In this embodiment, please refer to Figure 2 and Figure 3 The housing 10 includes a main housing 11 and a head housing 13. The main housing 11 is fixedly connected to the head housing 13. A bearing chamber 132 is formed in the head housing 13. The driving section of the output shaft 24 extends into the bearing chamber 132, thereby extending into the head housing 13, and is supported on the head housing 13 through the front bearing 40. A rear bearing chamber is formed in the main housing 11. The rear bearing 42 is accommodated in the rear bearing chamber. The positioning section of the output shaft 24 is supported on the main housing 11 through the rear bearing 42. The electric tool also includes a working shaft 80 for mounting a working head. The working shaft 80 is disposed in the head housing 13. The working shaft 80 is transmission-connected to the driving section and is driven to rotate by the driving section to drive the working head to perform a working task.

[0043] Specifically, the stator assembly 23, the rotor assembly 21 and the impeller 30 are arranged in the main housing 11, the air inlet is arranged in the main housing 11, and the air outlet 12 is arranged in the head housing 13. After the airflow passes through the impeller 30, it needs to pass through the inner space of the head housing 13 on the way to the air outlet 12. Since the inner wall of the head housing 13 is uneven, the noise caused by the chaotic collision of the airflow is relatively large, which needs to be improved.

[0044] The air guide plate 50 is used to guide the flow direction of the airflow and fix the front bearing 40, thereby reducing noise and improving the fixing effect of the front bearing. Please refer to 2. The air guide plate 50 is fixedly connected to the housing 10 by a fastener 60. In the axial direction of the motor output shaft 24, the front bearing 40, the air guide plate 50, and the impeller 30 are arranged in sequence, and the air guide plate 50 is located between the front bearing 40 and the impeller 30. The airflow flowing out of the impeller 30 is guided by the air guide plate, which can rectify the airflow, reduce the noise caused by it, and fix the front bearing at the same time.

[0045] See also Figure 4 As shown, the wind guide plate 50 includes a pressure plate portion 51 and a wind guide portion 53. The wind guide portion 53 surrounds the circumference of the pressure plate portion 51 and is used to guide the airflow direction and rectify the airflow. Figure 5 As shown, the air guide 53 includes a plurality of blades 531 for guiding the airflow, and the blades 531 are arranged at intervals in the circumferential direction, preferably, evenly spaced, and wind gaps are formed between adjacent blades 531. The shape of the blades defines the direction of the wind gaps, and the airflow flows in from the air inlet and passes through the wind gaps between the blades, thereby achieving rectification of the airflow direction, facilitating the airflow to flow toward the air outlet, and reducing the probability of random collisions with the inner wall of the housing, thereby reducing the noise generated thereby.

[0046] Please combine Figure 2 , 3 and Figure 4 As shown, the plate surface of the pressure plate portion 51 facing away from the impeller 30 abuts against the front bearing 40 and the bearing chamber 132, and is used to position the front bearing 40 and keep the front bearing 40 in the bearing chamber 132. The pressure plate portion 51 is provided with a through positioning hole 512, and the fastener 60 is passed through the positioning hole 512 and is screwed and fixed to the housing 10. In other words, the air guide pressure plate 50 is fixed to the housing 10 by the fastener 60. Specifically, the fastener 60 is a fastening bolt, and after the fastening bolt 60 passes through the positioning hole 512, it is locked with the housing 10, thereby achieving the fixation of the air guide pressure plate 50 to the housing 10.

[0047] The electric tool provided in this embodiment is provided with an air guide pressure plate, and the airflow is guided by the circumferential blades of the air guide pressure plate, so that the probability of the airflow colliding with the inner wall of the housing and the noise generated thereby can be reduced; after the air guide pressure plate is fixed to the housing, it is pressed against the front end bearing and the bearing chamber to fix the front end bearing, thereby improving the positioning reliability of the front end bearing. The utility model reduces the airflow noise and solves the problem of reliable fixing of the front end bearing.

[0048] Since the air guide pressure plate is directly fixedly connected to the housing through the pressure plate portion, and the front end bearing is pressed and fixed through the pressure plate portion, in order to ensure the reliability of the fixation. In a specific embodiment, the pressure plate portion 51 and the air guide portion 53 are made of different materials, the strength of the pressure plate portion 51 is greater than the strength of the air guide portion 53, and the air guide portion 53 is integrally formed with the pressure plate portion 51. The pressure plate portion is made of a material with greater structural strength, which can suppress its deformation during the fixing and pressing process, ensuring the reliable fixation of the front end bearing and the position consistency before and after the air guide portion is locked.

[0049] The above-mentioned "strength" refers to the strength of the mechanical properties of a material or object in resisting fracture and excessive deformation when subjected to force. The greater the strength, the stronger the ability of the object or material to resist external force damage or excessive deformation.

[0050] In a specific embodiment, the air guide part is made of plastic material, and the pressure plate part is made of metal material. During the injection molding process of the air guide part, the pressure plate part is used as an insert for injection molding of the air guide part. The pressure plate part is placed in a molding mold of the air guide part, and the air guide part is directly molded on the pressure plate part, and closely cooperates with the pressure plate part to form an integrated structure. In this way, the pressure plate part and the air guide part do not need an additional connection structure, which can improve assembly efficiency and relative positioning accuracy.

[0051] In order to improve the reliability of the axial positioning of the air guide part and the pressure plate part. In one embodiment, please combine Figure 4 and Figure 5 The air guide portion 53 includes an annular base 530, and the blades 531 extend radially outward from the peripheral side surface of the base 530, and the base 530 wraps the circumferential outer edge of the pressure plate portion 51. Among them, the pressure plate portion 51 is plate-shaped as a whole, including two opposite plate-shaped surfaces and a peripheral side surface surrounding the center line of the pressure plate portion 51, and "wrapping" is understood as the base 530 is combined with the peripheral side surface of the pressure plate portion 51 and the outer edges of the two plate-shaped surfaces. In the axial direction, the base 530 has a limited blocking structure on both sides of the plate surface of the pressure plate portion 51, and the pressure plate portion 51 is limited in the base 530, and the base 530 and the two side plate surfaces of the pressure plate portion 51 are integrally bonded. In this way, the stability of the axial position of the air guide portion and the pressure plate portion can be guaranteed, and the reliability of the one-piece molding structure can be improved.

[0052] In order to improve the reliability of the circumferential positioning of the air guide portion and the pressure plate portion. In some embodiments, please combine Figure 5 and Figure 6The circumferential outer edge of the pressure plate portion 51 is provided with a recess 510, and the air guide portion 53 includes a chimera 533 located in the recess 510 and matching the shape of the recess 510. During the molding process of the air guide portion, the chimera 533 matching the shape of the recess 510 is formed, and the chimera 533 is embedded in the recess 510, which can increase the resistance of the air guide portion and the pressure plate portion to relative rotation in the circumferential direction, and ensure the reliability of the circumferential positioning of the pressure plate portion and the air guide portion.

[0053] In one embodiment, see Figure 6 In the radial direction of the output shaft, the air guide portion 23 is located outside the fastener 60. In this way, the tightening operation of the fastener will not be transmitted to the air guide portion, and the air guide portion will not be subjected to the reaction force due to the tightening operation, thereby ensuring that the air guide portion will not be deformed by the external force of the tightening operation, thereby improving the reliability and stability of the air guide portion.

[0054] Specifically, the pressure plate portion 51 is provided with a through positioning hole 512, and the housing 10 is further provided with a positioning portion 131 connected to the fastener 60. The fastener 60 is passed through the positioning hole 512 and is screwed and fixed to the positioning portion 131. In order to ensure the reliability of the front end bearing positioning, in one embodiment, see Figure 5 , 7 and Figure 8 As shown, the end surface of the positioning portion 131 is flush with the end surface of the bearing chamber 132, and the pressure plate portion 51 is a flat plate, and the pressure plate portion 51 is in contact with the end surfaces of the positioning portion 131 and the bearing chamber 132. The tightening operation of the fastener causes the pressure plate portion to be pressed against the positioning portion and the bearing chamber, and the end surfaces of the positioning portion and the bearing chamber are flush, thereby suppressing the deformation of the pressure plate portion and ensuring that it can reliably press the front end bearing.

[0055] It should be noted that the pressure plate portion is a flat plate, which means that the pressure plate portion has a relatively flat plate surface, and the relatively flat plate surface can simultaneously press the end surface of the bearing chamber and the positioning portion during the locking operation. However, it is not excluded that the outer edge or inner edge of the pressure plate portion has a partially protruding mechanism. In a specific embodiment, the plate surface of the pressure plate portion 51 close to the bearing chamber 132 is a plane.

[0056] In a specific embodiment, without considering the flange 513, the two plate-like surfaces of the pressing plate portion 51 are roughly parallel, the distance between the two plate-like surfaces is the thickness of the pressing plate portion 51, and the plane located between the two plate-like surfaces of the pressing plate portion 51, parallel to the two plate-like surfaces and at the same distance is defined as the central plane of the pressing plate portion 51, and the plane passing through the thickness center of the air guide portion 53 and perpendicular to the output shaft 24 is the central plane of the air guide portion 53. Preferably, the central plane between the two plate-like surfaces of the pressing plate portion 51 is coplanar with the central plane of the air guide portion 53 perpendicular to the output shaft 24. In this way, the center of the air guide portion and the pressing plate portion is centered, the axial size is compact and small, and the structure is more reliable.

[0057] In this embodiment, the positioning portion 131 is located on the outside of the bearing chamber 132, and the number of the positioning portions 131 is 3, which are arranged around the bearing chamber 132. Preferably, the positioning portions 131 are evenly spaced. Correspondingly, the number of the fasteners 60 is also 3, which correspond one to one with the positioning portions 131. Of course, there are many options for the number of the positioning portions 131, which are not limited here. Specifically, the fastener 60 is a fastening bolt, which passes through the positioning hole 512 and is locked with the positioning portion 131, thereby achieving the fixation of the air guide pressure plate and the housing.

[0058] In order to reduce the probability of dust entering the front bearing through the air guide plate, in a specific embodiment, please combine Figure 5 and 8 As shown, the pressure plate portion 51 includes a flange 513 close to the output shaft 24, the flange 513 surrounds the circumference of the output shaft 24, and extends to the side close to the impeller 30. The surface of the impeller 30 facing the pressure plate portion 51 is inwardly recessed to form a groove structure 32, and the flange 513 partially extends into the groove structure 32, or the flange 513 is opposite to the groove structure 32. The probability of foreign matter reaching the vicinity of the output shaft and the front end bearing from the outside is reduced, thereby preventing foreign matter from contaminating the front end bearing and preventing the guide from affecting the normal operation of the front end bearing.

[0059] Specifically, the bottom of the groove structure 23 includes an axially extending convex rib 321, and the convex rib 421 is arranged at intervals relative to the flange 513, and the flange 513 and the groove structure 23 form a labyrinth structure. The arrangement of the convex rib makes the path for external dust to enter the output shaft and the front end bearing more tortuous and narrow, which can further isolate the dust.

[0060] It should be noted that “the flange portion extends into the groove structure” is understood to mean that the flange exceeds the plane where the end edge of the side wall defining the groove structure is located, and extends a certain length into the groove structure, but does not reach the bottom of the groove structure.

[0061] The electric tool provided in this embodiment, through the integrally formed wind guide pressure plate, not only realizes the rectification of the cooling airflow and reduces the airflow noise, but also realizes the compression and positioning of the front end bearing, thereby ensuring the reliability of the front end bearing fixation.

[0062] Obviously, the above described embodiments are only a part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, ordinary technicians in this field can make other different forms of changes or modifications without creative work, which should fall within the scope of protection of the utility model.

Claims

1. An electric tool, characterized in that: include: A housing is provided with an air inlet and an air outlet; A motor, disposed in the housing, comprising an output shaft for outputting rotational power; An impeller, fixedly disposed on the driving section of the output shaft, and rotating synchronously with the output shaft to generate a cooling airflow; A front end bearing is sleeved on the driving section and is located on a side of the impeller away from the rotor assembly of the motor, and the front end bearing is accommodated in a bearing chamber formed by the housing; An air guide pressure plate is located between the impeller and the front end bearing in the axial direction of the motor. The air guide pressure plate includes a pressure plate portion and an air guide portion. The air guide portion surrounds the circumference of the pressure plate portion. The plate surface of the pressure plate portion facing away from the impeller abuts against the front end bearing and the bearing chamber. The pressure plate portion and the casing are pressed and fixed by fasteners. The air guide portion includes a plurality of blades for guiding airflow. The airflow flows in from the air inlet, is rectified by the blades, and then flows out through the air outlet.

2. The electric tool according to claim 1, characterized in that: The pressing plate portion and the air guide portion are made of different materials, the strength of the pressing plate portion is greater than the strength of the air guide portion, and the air guide portion is integrally formed with the pressing plate portion.

3. The electric tool according to claim 2, characterized in that: The wind guide portion includes an annular base, the blades extend radially outward from the peripheral side surface of the base, and the base wraps the peripheral outer edge of the pressure plate portion.

4. The electric tool according to claim 2, characterized in that: A recess is arranged on the circumferential outer edge of the pressure plate portion, and the air guide portion comprises a chimeric body located in the recess and matching the shape of the recess.

5. The electric tool according to claim 2, characterized in that: The pressing plate part is made of metal material, the air guide part is made of plastic, and the pressing plate part serves as an insert of the air guide part which is injection molded.

6. The electric tool according to claim 1, wherein: In the radial direction of the output shaft, the air guide portion is located outside the fastener.

7. The electric tool according to claim 1, wherein: The housing comprises a positioning portion connected to the fastener, an end surface of the positioning portion is flush with an end surface of the bearing chamber, and the pressure plate portion is a flat plate, and the pressure plate portion is in abutment contact with both the positioning portion and the end surface of the bearing chamber.

8. The electric tool according to claim 1, wherein: The pressure plate portion includes a flange close to the output shaft, the flange surrounds the circumference of the output shaft, the surface of the impeller facing the pressure plate portion is recessed inward to form a groove structure, the flange portion extends into the groove structure, or the flange is opposite to the groove structure.

9. The electric tool according to claim 8, characterized in that: The bottom of the groove structure includes a convex rib, the convex rib is arranged relatively and spaced apart from the flange, and the flange and the groove structure form a labyrinth structure.

10. The electric tool according to claim 1, wherein: A central plane between the two plate-shaped surfaces of the pressure plate portion is coplanar with a central plane of the air guide portion that is perpendicular to the output shaft.

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