A power tool

Abstract

The utility model belongs to electric tool technical field discloses a kind of electric tools, including rear shell, front shell and front cover;The inside fixed mounting of front shell has stator, the inside rotary mounting of stator has rotor, internal passage is formed between rotor and stator, external passage is formed between the inner wall of stator and front shell, and secondary filter screen is installed in front shell;The side surface of rear shell is equipped with air inlet, and primary filter screen is installed in the inside of air inlet;Internal passage and external passage are connected with the inside of rear shell;Front cover is equipped with air outlet, and internal passage and external passage are connected with air outlet.The utility model uses the classification filtering structure of primary filter screen cooperation secondary filter screen, primary screen intercepts large particle impurity, and secondary screen accurately filters iron end, effectively prevents iron end from invading internal passage between rotor and stator, avoids the fault such as motor burnout caused by iron end accumulation, significantly prolongs motor service life.

Description

TECHNICAL FIELD

[0001] The utility model relates to electric tool technical field, especially electric tool. BACKGROUND

[0002] In the electric tool technology iteration process, the brushless motor has become the core power unit of the angle grinder, electric drill, electric saw and other multi-category tools with the technical advantages of high efficiency output, long life cycle and low operation and maintenance cost, and deeply drives product performance upgrading and industry technology change.

[0003] But in the typical operation scene such as metal cutting and building polishing, the dust iron end (containing fine particulate matter such as metal debris and iron powder) generated by tool operation constitutes a serious challenge to the stable operation of the brushless motor - in the operation process, the dust iron end invades the motor interior along with the airflow or mechanical gap and is deposited in the stator / rotor gap area. Because the rotor / stator inner ring of the brushless motor has strong magnetism, the invading dust iron end will be quickly adsorbed and continuously accumulated, forming a "magnetic impurity deposition layer", thereby causing motor stall.

[0004] When the thickness of the deposition layer exceeds the motor design gap threshold, the relative rotation resistance of the stator / rotor increases sharply, directly triggering the stall failure; long-term stall causes winding overload, resulting in uncontrollable temperature rise, and eventually causing motor burnout. Such failure not only greatly shortens the tool service life and increases the end user maintenance cost, but also has safety hazards such as motor fire, which seriously restricts the release of the advantages of the brushless motor and becomes an industry common technical problem.

[0005] In the prior art, a filter screen is provided on the electric tool shell for filtering the air entering the shell interior, but the traditional filter screen has a large aperture (mostly millimeter level), which can only intercept large particle impurities and cannot form effective filtration of micron-level dust iron end (the particle size of the dust iron end generated by operation is usually ≤ 150 μm), resulting in a dust prevention scheme that is a mere formality and fails to fundamentally solve the brushless motor pollution problem.

[0006] Some are generally fully enclosed stator and rotor, such as using wool felt full closure, which has a complex structure, poor heat dissipation and high use cost.

[0007] Therefore, an electric tool is proposed. SUMMARY

[0008] The utility model aims to provide an electric tool, thereby solving or at least alleviating one or more of the above problems and other aspects in the prior art.

[0009] In order to achieve the above purpose, the main technical scheme adopted by the utility model comprises:

[0010] A power tool includes a rear housing, a front housing, and a front cover;

[0011] A stator is fixedly installed inside the front housing, and a rotor is rotatably installed inside the stator. An internal channel is formed between the rotor and the stator, and an external channel is formed between the stator and the inner wall of the front housing. A secondary filter screen for filtering iron filings in the air entering the internal channel is installed at one end of the front housing near the rear housing.

[0012] The rear housing is installed at one end of the front housing, the front cover is installed at the end of the front housing away from the rear housing, and an air inlet is provided on the side of the rear housing, with a primary filter screen installed inside the air inlet;

[0013] The air inlet of both the internal channel and the external channel is connected to the interior of the rear housing.

[0014] An air outlet is provided on the front cover, and the air outlet of both the internal channel and the external channel is connected to the air outlet.

[0015] Fan blades are fixedly installed on the rotor shaft.

[0016] In a power tool according to the present invention, an assembly groove is provided in the middle of one end of the front housing near the rear housing, and the secondary filter screen is fixedly installed in the assembly groove by screws.

[0017] In a power tool according to the present invention, the rear housing is fixedly mounted on the front housing by bolts.

[0018] In an electric tool according to the present invention, the primary filter screen is 40-60 mesh, and the secondary filter screen is 150-300 mesh.

[0019] This utility model has at least the following beneficial effects:

[0020] The system employs a graded filtration structure with a primary filter and a secondary filter. The primary filter intercepts large particles of impurities, while the secondary filter precisely filters iron filings. This effectively prevents iron filings from entering the internal channels between the rotor and stator, avoiding motor stalling, motor burnout, and other malfunctions caused by iron filings. This significantly extends the motor's lifespan and reduces user maintenance costs.

[0021] The secondary filter screen can be detached and installed via assembly slots and screws, making it easy to clean or replace regularly and ensuring continuous and effective filtration.

[0022] The rear housing is fixed to the front housing with bolts, which makes the connection secure and easy to disassemble, facilitating the maintenance of internal components.

[0023] The tiered filtration design reduces the probability of clogging a single filter, extends the filter maintenance cycle, and improves user convenience. Attached Figure Description

[0024] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0025] Figure 1 This is a schematic diagram of the structure of the power tool of this utility model;

[0026] Figure 2 This is a schematic diagram of the exploded structure of the rear shell of this utility model;

[0027] Figure 3 This is a schematic diagram of the front housing of this utility model;

[0028] Figure 4 This is a top view of the front housing of this utility model;

[0029] Figure 5 This is a schematic diagram of the airflow path into the front housing.

[0030] Explanation of icon numbers:

[0031] 1. Rear housing; 101. Air inlet; 102. Primary filter; 2. Front housing; 201. Internal channel; 202. External channel; 203. Assembly slot; 3. Front cover; 301. Air outlet; 4. Secondary filter; 5. Stator; 6. Rotor; 601. Fan blade. Detailed Implementation

[0032] The following will describe in detail the implementation of this application with reference to the accompanying drawings and embodiments, so that the implementation process of how this application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0033] Please refer to Figures 1 to 5As shown, this embodiment provides an electric tool, including a rear housing 1, a front housing 2, and a front cover 3. A stator 5 is fixedly installed inside the front housing 2, and a rotor 6 is rotatably installed inside the stator 5. An internal channel 201 is formed between the rotor 6 and the stator 5, and an external channel 202 is formed between the stator 5 and the inner wall of the front housing 2. A secondary filter 4 for filtering iron filings in the air entering the internal channel 201 is installed at one end of the front housing 2 near the rear housing 1. The rear housing 1 is mounted on one side of the front housing 2. At the end of the front housing 2, the front cover 3 is installed at the end away from the rear housing 1. An air inlet 101 is provided on the side of the rear housing 1. A primary filter 102 is installed inside the air inlet 101. The air inlet end of the internal channel 201 and the air inlet end of the external channel 202 are both connected to the interior of the rear housing 1. An air outlet 301 is provided on the front cover 3. The air outlet end of the internal channel 201 and the air outlet end of the external channel 202 are both connected to the air outlet 301. A fan blade 602 is fixedly installed on the rotating shaft 601 of the rotor 6.

[0034] Working principle: When the power tool is working, the rotor 6 rotates inside the stator 5, and the fan blades 602 mounted on the rotor 6 shaft 601 rotate accordingly, generating suction. External air enters through the air inlet 101 on the side of the rear housing 1, first passing through the primary filter 102, which initially filters out larger particles of impurities. Then the air splits into two paths: one path enters the external channel 202 between the stator 5 and the inner wall of the front housing 2, and the other path passes through the secondary filter 4 to filter out fine impurities such as iron filings before entering the internal channel 201 between the rotor 6 and the stator 5. Both airflows eventually exit from the air outlet 301 of the front cover 3. During this process, heat dissipation is achieved inside the motor. At the same time, the secondary filter 4 effectively prevents iron filings from entering the internal channel 201, protecting the motor. Moreover, some air containing iron filings is directly discharged from the external channel 202, reducing the filtration load of the secondary filter 4 and extending its service life. In addition, because the internal channel 201 is equipped with the secondary filter 4, and the external channel 202 is directly connected to the interior of the rear housing 1, the resistance when air enters the internal channel 201 is relatively large, so that most of the air containing iron filings will naturally flow into the external channel 202.

[0035] An assembly groove 203 is provided in the middle of one end of the front housing 2 near the rear housing 1, and the secondary filter screen 4 is fixedly installed in the assembly groove 203 by screws.

[0036] The assembly slot 203 provides a precise installation position for the secondary filter screen 4, which is securely mounted on the front housing 2 using screws. This detachable installation method allows users to easily open the front housing 2, unscrew the screws, and clean or replace the secondary filter screen 4 when a large amount of iron filings accumulate there, ensuring its continuous and effective filtration performance.

[0037] In this embodiment, the rear housing 1 is fixedly mounted on the front housing 2 by bolts.

[0038] The bolted fastening method provides a secure connection between the rear housing 1 and the front housing 2. During the operation of the power tool, vibrations and other forces are generated. The bolted connection can withstand these forces, ensuring that the rear housing 1 and the front housing 2 will not loosen or separate due to vibration, thus maintaining the stability of the overall structure of the power tool. At the same time, this fastening method facilitates operation during production and assembly, and also makes it convenient for later inspection and maintenance of internal components such as the motor.

[0039] In this embodiment, the primary filter 102 is 40-60 mesh, and the secondary filter 4 is 150-300 mesh.

[0040] The primary filter 102, with a mesh size of 40-60, is able to filter out larger particles of impurities, such as large dust and debris generated during operation, providing initial purification of the air entering the power tool. The air filtered by the primary filter 102 can then dissipate heat from the control and power modules inside the rear housing 1, while reducing the filtration burden on the secondary filter 4. The secondary filter 4, with a mesh size of 150-300, has even finer pores, effectively intercepting smaller particles such as iron filings, preventing them from entering the internal channel 201. This protects the motor's stator and rotor from the impact of iron filings, avoiding motor malfunctions caused by iron filings accumulation and extending the motor's lifespan.

[0041] The foregoing description illustrates and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the present invention's conception through the foregoing teachings or related technical or knowledge. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A power tool, characterized in that, Includes the rear housing, front housing, and front cover; A stator is fixedly installed inside the front housing, and a rotor is rotatably installed inside the stator. An internal channel is formed between the rotor and the stator, and an external channel is formed between the stator and the inner wall of the front housing. A secondary filter screen for filtering iron filings in the air entering the internal channel is installed at one end of the front housing near the rear housing. The rear housing is installed at one end of the front housing, the front cover is installed at the end of the front housing away from the rear housing, and an air inlet is provided on the side of the rear housing, with a primary filter screen installed inside the air inlet; The air inlet of both the internal channel and the external channel is connected to the interior of the rear housing. An air outlet is provided on the front cover, and the air outlet of both the internal channel and the external channel is connected to the air outlet. Fan blades are fixedly installed on the rotor shaft.

2. The power tool according to claim 1, characterized in that: An assembly groove is provided in the middle of one end of the front housing near the rear housing, and the secondary filter screen is fixedly installed in the assembly groove by screws.

3. The power tool according to claim 1, characterized in that: The rear housing is fixedly mounted on the front housing by bolts.

4. A power tool according to claim 2, characterized in that: The primary filter screen is 40-60 mesh, and the secondary filter screen is 150-300 mesh.

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