An installation method for the commutator of a high-overload-resistant DC brushed motor

Abstract

The present invention discloses a method for installing a commutator of a high-overload-resistant DC brushed motor, which relates to the technical field of motor commutators and is used to solve the problem that in some high-end application fields in the prior art, the installation methods of traditional commutators cannot simultaneously meet the requirements of miniaturization and light weight of DC brushed motors and the high-overload resistance and reliability of the motors. The present invention includes the following steps: Step S1: Determine the sizes of the central shaft hole of the commutator 2 and the rotor shaft according to the assembly clearance value between the central shaft hole of the commutator and the rotor shaft; Step S2: Install the commutator. The present invention can improve the reliability of DC brushed motors in high-overload environments without adding additional complex structures within a limited space, and at the same time meet the requirements of miniaturization and light weight of the motors.

Description

Technical Field

[0001] The present invention relates to the technical field of motor commutators, and particularly to an installation method for a high-overload-resistant DC brushed motor commutator. Background Art

[0002] In some high-end application fields, DC brushed motors are required to have high-overload resistance and reliability, and at the same time, there are requirements for miniaturization and light weight. However, miniaturization and light weight mean that complex structures cannot be used in a narrow space. The common method is to drill holes in the commutator and fix it with multiple bolts around. However, this method increases the weight of the commutator and does not meet the light-weight requirement. At the same time, the holes will also weaken the reliability of the commutator. Another method is to use an interference fit between the commutator and the shaft, and an external force is required to press the commutator onto the shaft. This method will generate large internal stresses, and the commutator and the shaft are extremely easy to break in a high-overload impact environment. Summary of the Invention

[0003] In view of the above analysis, the present invention aims to provide an installation method for a high-overload-resistant DC brushed motor commutator to solve the problem that the installation methods of traditional commutators in some high-end application fields of the prior art cannot simultaneously meet the requirements of miniaturization and light weight of DC brushed motors and the requirements of high-overload resistance and reliability of the motors.

[0004] The object of the present invention is mainly achieved through the following technical solutions:

[0005] An installation method for a high-overload-resistant DC brushed motor commutator includes the following steps:

[0006] Step S1: Determine the sizes of the central shaft hole of the commutator 2 and the rotor shaft according to the assembly clearance value between the central shaft hole of the commutator and the rotor shaft.

[0007] Step S2: Install the commutator.

[0008] Further, in the step 1, the assembly clearance value between the commutator and the rotor shaft is 0.012 mm to 0.018 mm.

[0009] Further, the step 2 specifically includes:

[0010] Step S2.1: Machine a glue storage groove on the installation surface of the rotor shaft and fill it with resin.

[0011] Step S2.2: Use a positioning tooling and a pressing device to install the commutator onto the shaft.

[0012] Further, the glue storage groove is a spiral groove.

[0013] Further, the ratio of the depth of the glue storage tank to the diameter of the installation end of the rotor shaft is 1:25 to 1:20; the ratio of the width to the depth of the glue storage tank is 0.6, and the spiral angle of the glue storage tank is 20°.

[0014] Further, the step S2.2 specifically includes:

[0015] Step S2.2.1: Fix the shaft using a positioning tooling and a pressing device, and assemble the commutator.

[0016] Step S2.2.2: Clean up the excess resin glue solution, let it stand for 24 h, and the DG-2 resin adhesive cures to complete the installation of the commutator.

[0017] Further, in the step S2.2.1,

[0018] The positioning tooling includes an upper die and a lower die; the pressing device includes an upper workbench, a lower workbench, and a guiding structure; the upper workbench is provided with a central through hole, and the upper die can move up and down in the central through hole; the guiding structure is used to guide the movement of the upper die.

[0019] The lower workbench is used to fix the lower die, and a first conical surface, a first cylindrical surface, a second conical surface, and a second cylindrical surface are coaxially arranged inside the upper die.

[0020] Further, during assembly, the axis of the first conical surface coincides with the axis of the shaft and ends at the end of the shaft; the diameter of the first cylindrical surface is the same as the diameter of the shaft section that cooperates with the commutator; one end of the first cylindrical surface is connected to the first conical surface, and the other end is connected to the second conical surface; the other end of the second conical surface is arranged at the end of the commutator; the diameter of the second cylindrical surface is the same as the outer diameter of the commutator.

[0021] A positioning flange is arranged on the second cylindrical surface, and the shape of the positioning flange is the same as that of the groove outside the commutator for positioning the commutator.

[0022] Further, the step 2.2.1 is specifically: Fix the shaft with the lower die; insert the commutator into the second cylindrical surface of the upper die so that the elastic positioning flange is stuck into the groove outside the commutator.

[0023] Operate the pressing device, and under the guidance of the guiding structure, the upper die presses down to assemble the commutator to the shaft.

[0024] Further, in the step S2.2.1, specifically:

[0025] The unilateral clearance between the installation surface of the commutator and the installation surface of the shaft ≥ 0.006 mm; the installation distance between the commutator and the end of the shaft close to the commutator ≥ 3 mm.

[0026] Compared with the prior art, the present invention can at least achieve one of the following beneficial effects:

[0027] (1) Compared with the prior art, in the present invention, the commutator and the rotor shaft adopt an assembly small clearance fit between 0.012 mm and 0.018 mm, which avoids the situation that in the traditional interference fit, an external force is required to press the commutator onto the shaft, generating a large internal stress, and the commutator is extremely prone to fracture in a high-overload impact environment; it also avoids the loosening and displacement of components during the impact process in the case of a large clearance fit, and improves the connection stability between components. The small clearance fit can reduce the impact stress concentration between the commutator and the shaft, help disperse the impact load, make the acting force between components more evenly distributed under the impact load, effectively absorb and disperse energy; it can reduce the impact deformation; in the case of repeated impacts, the small clearance fit helps reduce the cumulative damage caused by too large a clearance.

[0028] (2) Compared with the prior art, in the present invention, a spiral glue storage groove is provided at the joint surface of the rotor shaft and the commutator, which increases the contact area and bonding force between the resin and the interface, and improves the impact resistance at the joint. The ratio of the groove depth of the spiral groove to the diameter of the installation end of the rotor shaft is 1:25 to 1:20, which improves the impact resistance without damaging the shaft strength. The ratio of the groove width to the groove depth of the spiral groove is 0.6, and the glue can be evenly distributed in the glue storage groove, avoiding stress concentration areas during impact; the spiral angle of the glue storage groove is 20°, and the absolute value of the cross damping is the largest, enhancing the impact resistance performance at the joint.

[0029] (3) Compared with the prior art, in order to improve the high-precision concentricity of the commutator and the shaft and reduce the additional stress caused by misalignment and reduce the anti-overload capacity, in the present invention, the positioning tooling is coaxially provided with a first conical surface, a first cylindrical surface, a second conical surface and a second cylindrical surface. The first conical surface starts from the extension line of the axis of the shaft. Using the centering function of the conical surface, the commutator is positioned to ensure the fitting accuracy between the shaft and the commutator, optimize the vibration of the rotor and reduce the gyroscopic moment effect generated by the rotor, so as to ensure that the motor can operate efficiently, safely, reliably and stably.

[0030] (4) After the commutator is installed on the rotor shaft in the present invention, the rotor assembly is installed on the motor housing. When the motor rotor rotates at a high speed during operation, during high-overload impact, the rotor and the commutator will oscillate in the motor housing. At the limit position, the end of the rotor shaft will contact the rear cover of the motor, and the commutator will move with the rotor. To ensure that the rotor rotates without jamming, the unilateral clearance between the commutator mounting surface and the shaft mounting surface ≥ 0.006 mm; the mounting distance between the commutator and the end of the shaft ≥ 3 mm.

[0031] (5) In order to make the connection between the commutator and the rotor shaft resistant to impact, in the present invention, a resin is provided in the glue storage groove as a shock-absorbing material to absorb and disperse the load during impact.

[0032] Other features and advantages of the present invention will be set forth in the following description, and in part will be obvious from the description, or may be learned by practice of the present invention. The objectives and other advantages of the present invention may be realized and attained by the structure particularly pointed out in the written description and the drawings. Description of the Drawings

[0033] The drawings are only for the purpose of illustrating specific inventions and are not considered as limitations to the present invention. Throughout the drawings, the same reference numerals denote the same components.

[0034] Figure 1 Installation flow chart of a specific embodiment;

[0035] Figure 2 Structural schematic diagram of a commutator of a specific embodiment;

[0036] Figure 3 Structural schematic diagram of a rotor shaft of a specific embodiment;

[0037] Figure 4 Structural schematic diagram of a pressing device and a positioning tooling of a specific embodiment;

[0038] Figure 5 Structural schematic diagram of an upper die of a specific embodiment;

[0039] Figure 6 Structural schematic diagram of a high-overload impact resistance test of a specific embodiment.

[0040] Reference Numerals:

[0041] 1 - Shaft, 101 - Glue storage groove, 2 - Commutator, 201 - Groove, 3 - Positioning tooling, 301 - Upper die, 3011 - First conical surface, 3012 - First cylindrical surface, 3013 - Second conical surface, 3014 - Second cylindrical surface, 3015 - Positioning flange, 302 - Lower die, 4 - Pressing device, 401 - Upper workbench, 402 - Lower workbench, 403 - Guide rod, 404 - Sleeve, 405 - Spring. Detailed Embodiments

[0042] The following will specifically describe the preferred invention of the present invention in conjunction with the drawings, wherein the drawings form a part of the present invention and are used together with the invention of the present invention to explain the principle of the present invention.

[0043] This embodiment provides an installation method for a commutator of a high-overload DC brushed motor, as Figure 1 shown, including the following steps:

[0044] Step S1: Determine the dimensions of the central shaft hole of the commutator 2 and the rotor shaft 1 according to the assembly clearance value between the commutator 2 and the rotor shaft 1;

[0045] Step S2: Install the commutator 2.

[0046] In the said step S1, it specifically includes:

[0047] Step S1.1: Determine the assembly clearance value between the central shaft hole of the commutator 2 and the rotor shaft 1;

[0048] The commutator 2 and the rotor shaft 1 are fitted by the selective assembly method. Specifically, the assembly clearance between the central shaft hole of the commutator 2 and the rotor shaft 1 is between 0.012 mm and 0.018 mm.

[0049] Compared with the prior art, the commutator 2 and the rotor shaft 1 adopt a small clearance fit, which avoids the situation that in the traditional interference fit, an external force is required to press the commutator 2 onto the shaft, generating a large internal stress, and the commutator 2 and the rotor shaft 1 are extremely prone to fracture in a high-overload impact environment; it also avoids the loosening and displacement of the commutator 2 during the impact process in the case of a large clearance fit, and improves the connection stability between the commutator 2 and the shaft 1. The small clearance fit can reduce the impact stress concentration between the commutator 2 and the shaft 1, help to disperse the impact load, optimize the interaction between the shaft 1 and the commutator 2, make the acting force between the shaft 1 and the commutator 2 more uniform under the impact load, and effectively absorb and disperse energy; it can increase the overall rigidity of the structure and reduce the impact deformation; in the case of repeated impacts, the small clearance fit helps to reduce the cumulative damage caused by too large a clearance.

[0050] Step S1.2: Determine the dimensions and tolerances of the rotor shaft 1 and the commutator 2.

[0051] As Figure 2 shown, the commutator 2 has a central hole. In this embodiment, the dimension of the central hole of the commutator 2 is The dimension of the installation and fit part of the shaft 1 and the commutator 2 is The fit clearance is 0.016 mm.

[0052] In the said step S2, it specifically includes:

[0053] Step S2.1: Machine a glue storage groove 101 on the rotor shaft 1 and fill it with resin;

[0054] Step S2.2: Install the commutator 2 onto the shaft 1, and the unilateral clearance between the installation surface of the commutator and the installation surface of the shaft is ≥ 0.006 mm.

[0055] Step S2.1.1: Determine the installation surface of the rotor shaft 1;

[0056] As Figure 3 shown, the installation surface of the rotor shaft 1 is from near the end of the rotor shaft 1 to the shaft shoulder of the rotor shaft 1.

[0057] Step S2.1.2: Machine a glue storage groove 101 on the mounting surface of the rotor shaft 1;

[0058] Specifically, the glue storage groove 101 is a spiral groove. The glue storage groove 101 is arranged as a spiral groove, which can increase the contact area between the resin and the interface, enhance the bonding force between the resin and the interface, and improve the impact resistance at the joint of the commutator and the shaft.

[0059] If the groove depth of the glue storage groove 101 is too large, it will weaken the bearing capacity of the shaft 1. The ratio of the groove depth of the glue storage groove 101 to the diameter of the mounting end of the rotor shaft 1 is set to be 1:25 - 1:20.

[0060] According to the influence of the spiral groove on the liquid film dynamic coefficient, when the ratio of the groove width to the groove depth is 0.6, the glue can be evenly distributed in the glue storage groove 101 and has good fluidity. Therefore, when stressed, the stress can be evenly distributed, avoiding stress concentration areas and improving the impact resistance of the connection part; when the spiral angle of the spiral groove is 20°, the absolute value of the cross damping between the two angles is the largest, so the ability to absorb vibration energy is the largest and the impact resistance performance is stronger. Therefore, the ratio of the groove width to the groove depth of the glue storage groove 101 is set to be 0.6, and the spiral angle is 20°.

[0061] Compared with the prior art, in this embodiment, a spiral glue storage groove 101 is provided at the joint surface of the rotor shaft 1 and the commutator 2, which increases the contact area and bonding force between the resin and the interface and improves the impact resistance at the joint. The ratio of the groove depth of the spiral groove to the diameter of the mounting end of the rotor shaft 1 is set to be 1:25 - 1:20, which improves the impact resistance without damaging the strength of the shaft. The ratio of the groove width to the groove depth of the spiral groove is set to be 0.6, so that the glue can be evenly distributed in the glue storage groove 101, avoiding stress concentration areas during impact; the spiral angle of the glue storage groove 101 is set to be 20°, and the absolute value of the cross damping is the largest, enhancing the impact resistance performance at the joint.

[0062] It should be noted that the machining direction of the glue storage groove 101 is the same as the installation direction of the commutator 2, that is, from the side close to the end of the rotor shaft 1 to the shaft shoulder of the rotor shaft 1.

[0063] Step S2.1.3: Fill the glue storage groove 101 with resin.

[0064] In the step S2.1.3, it specifically includes:

[0065] Step S2.1.3.1: Select resin;

[0066] In order to make the connection between the commutator 2 and the rotor shaft 1 shock-resistant, a damping material is provided in the glue storage groove 101 to absorb and disperse the load during impact. The damping material should have high elasticity, damping characteristics and mechanical properties, and have a low density to meet the lightweight requirements. In this embodiment, a resin with high viscosity, elasticity, damping characteristics and mechanical properties is selected as the damping material.

[0067] In this embodiment, the selected resin is DG-2 epoxy resin. As an alternative to this embodiment, it can also be polycarbonate, ABS resin or PBT resin.

[0068] DG-2 epoxy resin has high viscosity and can bond the commutator and the rotor shaft. The viscosity of DG-2 resin is 300-700 Pa·s at room temperature. It has high elasticity and can absorb and disperse vibration and impact energy when subjected to impact or vibration, and quickly return to its original state. It has a high damping coefficient, reaches the maximum value in the glass transition region, can absorb vibration energy to the greatest extent, reduce vibration, and has a large impact resistance. It has good mechanical properties. The shear strength of the selected resin is ≥18 Mpa, and the peel strength is ≥39.2 N / cm, and it can withstand the expected load and impact.

[0069] Compared with the prior art, in this embodiment, the glue storage groove is filled with a damping material resin, and the commutator 2 and the rotor shaft 1 are connected through the high viscosity of the resin. The high elasticity of the resin enables the connection to absorb and disperse vibration and impact energy when subjected to impact or vibration; the high damping coefficient can reduce vibration and has a large impact resistance. The shear strength of the resin is ≥18 Mpa, the peel strength is ≥39.2 N / cm, and the good mechanical properties can withstand the expected load and impact.

[0070] Step S2.1.3.2: Inject the resin into the glue storage groove 101.

[0071] First, clean the glue storage groove 101, and use a syringe to draw DG-2 resin and inject it into the glue storage groove 101 of the rotor shaft 1.

[0072] It should be noted that when injecting DG-2 resin, it should be injected slowly to discharge air to ensure that a complete glue layer can be formed by the DG-2 adhesive in the glue storage groove 101.

[0073] In step 2.2, the commutator 2 is installed on the shaft 1 by using a positioning tooling, which specifically includes:

[0074] Step S2.2.1: Fix the shaft 1 by using the pressing device 4 and the positioning tooling 3, and assemble the commutator 2;

[0075] To ensure the high-precision concentricity between the commutator 2 and the rotating shaft 1, and to reduce the additional stress caused by misalignment and thus reduce the anti-overload capacity, in this embodiment, a positioning tooling 3 and a pressing device 4 are used to assemble the commutator 2.

[0076] As Figure 4 shown, the positioning tooling 3 includes an upper die 301 and a lower die 302.

[0077] The pressing device 4 includes an upper workbench 401, a lower workbench 402, and a guiding structure 403. The guiding structure 403 includes a guide rod 4031, a sleeve 4032, and a spring 4033. A guide rod 4031, a sleeve 4032, and a spring 4033 are arranged between the upper workbench 401 and the lower workbench 402 for guiding the downward movement of the upper die 301. An external thread is provided on the outside of the upper die 301, and a threaded through hole is provided in the middle of the upper workbench 401 for installing the upper die 301.

[0078] The lower die 302 is fixed to the lower workbench 402. There is a long cylindrical groove inside the lower die 302 for fixing the rotating shaft 1. The inner part of the lower die 302 accommodates the shaft section from the end away from the commutator 2 to the shoulder step.

[0079] To improve the alignment between the commutator 2 and the rotating shaft 1, a first conical surface 3011, a first cylindrical surface 3012, a second conical surface 3013, and a second cylindrical surface 3014 are coaxially arranged inside the upper die 301. The axis of the first conical surface 3011 coincides with the axis of the rotating shaft 1, and the first conical surface 3011 ends at the end of the rotating shaft 1. The diameter of the first cylindrical surface 3012 is the same as the diameter of the shaft section that mates with the commutator 2; one end of the first cylindrical surface 3012 is connected to the first conical surface 3011, and the other end is connected to the second conical surface 3013. The other end of the second conical surface 3013 is arranged at the end of the commutator 2; the diameter of the second cylindrical surface 3014 is the same as the outer diameter of the commutator 2.

[0080] Furthermore, as Figure 5 shown, an elastic positioning flange 3015 is provided on the second cylindrical surface 3014 of the upper die 301. The positioning flange 3015 has the same shape as the groove 201 on the outside of the commutator 2 for positioning the commutator 2.

[0081] During assembly, first, the end of the rotating shaft 1 away from the commutator 2 is inserted into the lower die 302 until it reaches the shoulder end face; the commutator 2 is inserted into the second cylindrical surface 3014 of the upper die 301, so that the elastic positioning flange 3015 is snapped into the groove 201 of the commutator 2 to fix the commutator 2. The upper die 301 is screwed into the central threaded through hole of the upper workbench 401. The pressing device 4 is operated, and under the guidance of the guiding structure 403, the upper die 301 is pressed down until the commutator 2 is assembled to fit the other end face of the shoulder.

[0082] Compared with the prior art, in this embodiment, the positioning tooling 3 coaxially sets a first conical surface 3011, a first cylindrical surface 3012, a second conical surface 3013 and a second cylindrical surface 3014. And the first conical surface 3011 starts from the extension line of the axis of the rotating shaft 1. By using the centering effect of the conical surface, the positioning accuracy of the commutator 2 and the rotating shaft 1 is improved, the fitting accuracy between the rotating shaft 1 and the commutator 2 is ensured, the vibration of the rotor is optimized, and the gyroscopic moment effect generated by the rotor is reduced, so as to ensure that the motor can operate efficiently, safely, reliably and stably.

[0083] The commutator 2 is installed on the rotating shaft 1 and detected under a high-magnification image tester to ensure that the unilateral clearance between the mounting surface of the commutator 2 and the outer circular surface of the rotating shaft 1 is ≥0.006 mm, and to ensure the uniformity of the glue filling amount between the inner hole of the commutator 2 and the rotor rotating shaft 1.

[0084] It should be noted that after the commutator 2 is installed on the rotor rotating shaft 1, the rotor assembly is installed on the motor housing. When the motor rotor rotates at a high speed during operation, during high-overload impact, the rotor and the commutator 2 will oscillate in the motor housing. At the limit position, the end of the rotor rotating shaft 1 will contact the motor rear cover, and the commutator 2 will move with the rotor. To ensure that the rotor rotates without jamming, the installation distance between the commutator 2 and the end of the rotating shaft 1 is ≥3 mm.

[0085] Step S2.2.2: Clean up the excess resin glue solution, let it stand for 24 h, and the DG-2 resin adhesive cures to complete the installation of the commutator 2.

[0086] After the commutator 2 is installed by this method, the high-overload resistance ability is greatly improved, and the reliability of high-overload impact resistance reaches 100%. The assembled motor is installed on a certain steering gear to carry out a high-overload test. As Figure 6 shown, the high-overload impact resistance ability is ≥18000 g, and the safety factor of the structural strength is ≥2. The performance of the motor is tested before and after the test, and the motor works normally. After the commutator 2 is installed by using a small clearance fit and a glue storage groove 101, the high-overload resistance ability exceeds 13000 - 14000 g of the traditional installation method, and the reliability of the DC brushed motor in a high-overload environment is improved without adding additional complex structures in a limited space, while meeting the requirements of miniaturization and lightweight of the commutator 2.

[0087] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for installing a commutator of a high-overload-resistant DC brushed motor, characterized in that, It includes the following steps: Step S1: Determine the sizes of the central shaft hole of the commutator (2) and the rotor shaft (1) according to the assembly clearance value between the central shaft hole of the commutator (2) and the rotor shaft (1); the assembly clearance value between the commutator (2) and the rotor shaft (1) is 0.012 mm to 0.018 mm; Step S2: Install the commutator (2); Step S2.1: Machine a resin storage groove (101) on the installation surface of the rotor shaft (1) and fill it with resin; wherein, the resin storage groove (101) is a spiral groove; the ratio of the groove depth of the resin storage groove (101) to the diameter of the installation end of the rotor shaft (1) is 1:25 to 1:20; the ratio of the groove width to the groove depth of the resin storage groove (101) is 0.6, and the spiral angle of the resin storage groove (101) is 20°; Step S2.2: Use a positioning tooling (3) to install the commutator (2) onto the shaft (1); the positioning tooling (3) includes an upper die (301) and a lower die (302); a first conical surface (3011), a first cylindrical surface (3012), a second conical surface (3013), and a second cylindrical surface (3014) are coaxially arranged inside the upper die (301); Step S2.2.1: Fix the shaft (1) using a pressing device (4) and the positioning tooling (3), and assemble the commutator (2); the pressing device includes an upper workbench, a lower workbench, and a guiding structure. The guiding structure includes a guide rod, a sleeve, and a spring. The guiding structure is arranged between the upper workbench and the lower workbench and is used to guide the downward movement of the upper die; wherein, the upper die is installed on the upper workbench, and the lower die is fixed to the lower workbench; The lower die (302) fixes the shaft (1); install the commutator (2) into the second cylindrical surface (3014) of the upper die (301); the upper die (301) presses down to assemble the commutator (2) onto the shaft (1); Step S2.2.2: Clean up the excess resin glue, let it stand for 24 h, and the DG-2 resin adhesive cures to complete the installation of the commutator (2).

2. The installation method of the commutator of the high-overload-resistant DC brushed motor according to claim 1, wherein During assembly, the axis of the first conical surface (3011) coincides with the axis of the shaft (1) and ends at the end of the shaft (1); the diameter of the first cylindrical surface (3012) is the same as the diameter of the shaft section that mates with the commutator (2); one end of the first cylindrical surface (3012) is connected to the first conical surface (3011), and the other end is connected to the second conical surface (3013); the other end of the second conical surface (3013) is arranged at the end of the commutator (2); the diameter of the second cylindrical surface (3014) is the same as the outer diameter of the commutator (2); An elastic positioning flange (3015) is arranged on the second cylindrical surface (3014). The positioning flange (3015) has the same shape as the groove (201) outside the commutator (2) and is used for positioning the commutator (2).

3. The installation method of the commutator of the high-overload-resistant DC brushed motor according to claim 2, characterized in that, Step 2.2.1 further includes: When installing the commutator (2) into the second cylindrical surface (3014) of the upper die (301), make the elastic positioning flange (3015) snap into the groove (201) outside the commutator (2).

4. The installation method of the commutator of the high-overload-resistant DC brushed motor according to claim 3, characterized in that, In the specific step S2.2.1, it is as follows: The unilateral clearance between the mounting surface of the commutator (2) and the mounting surface of the rotating shaft (1) is ≥ 0.006 mm; the mounting distance between the commutator (2) and the end of the rotating shaft (1) close to the commutator (2) is ≥ 3 mm.

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