A miniature DC carbon brush motor with a powder removal structure

Abstract

This utility model discloses a miniature DC carbon brush motor with a dust removal structure, including a housing, a stator, a rotor, an insulating base, and a top cover. The housing has a pivot cavity, and the stator is located on the inner wall of the pivot cavity. The rotor includes a rotating shaft rotatably mounted in the pivot cavity, a magnetic coil located in the middle of the rotating shaft, and a commutator located on the upper part of the rotating shaft. The insulating base is located at the upper end of the pivot cavity and has a guide hole that extends radially through the insulating base. A support portion extends upward from the bottom wall of the guide hole, and dust removal channels are provided on both sides of the support portion. A carbon brush is slidably mounted in the guide hole, and the lower wall of the carbon brush is in contact with the support portion. The front end of the carbon brush can switch between abutting against or moving away from the wall of the commutator. The top cover is mounted above the insulating base and fixed to the upper end of the housing.

Description

Technical Field

[0001] This utility model relates to the field of brushed motors, and in particular to a miniature DC carbon brush motor with a powder discharge structure. Background Technology

[0002] When a DC brushed motor is running, the commutator and carbon brushes continuously change the direction of the current, thereby driving the motor to rotate. This causes the current in the motor to change according to a certain pattern, thus generating continuous torque to drive the motor. The two functions complement each other, working together to ensure the normal operation of the motor.

[0003] This can be understood as switching between the S and N poles by changing the current, thereby achieving tangency with the stator (magnet) and enabling the rotor to rotate.

[0004] However, the friction between the carbon brushes and the commutator generates conductive carbon brush dust. This dust can accumulate at the edges of the carbon brushes and in the commutator gap, causing a short circuit in the motor's internal wiring and leading to the following problems: 1. The motor cannot start, so the rotor's magnetic coil will repeatedly start; 2. This can easily cause excessive current, resulting in severe overheating of the magnetic coil, or even burnout.

[0005] The current practice is generally to stop and then restart the machine to avoid dust obstruction. Of course, there is also the method of adding a starting capacitor to increase the starting speed and thus avoid the problem of rotor stagnation, thereby cleaning the dust through rotation.

[0006] However, dust accumulation can still affect the motor's operational stability and lifespan.

[0007] For example, Chinese patent 202420964144.8 uses a shaft-driven powder discharge structure, but this structure is not suitable for smaller micro motors (due to the high difficulty in processing), thus presenting technical limitations. Utility Model Content

[0008] The main purpose of this invention is to propose a miniature DC carbon brush motor with a dust discharge structure, which aims to improve the dust discharge mechanism of the carbon brush and effectively reduce dust accumulation; thereby improving the service life and rotational stability of the motor (especially for the initial start-up stage).

[0009] To achieve the above objectives, this utility model proposes a miniature DC carbon brush motor with a powder discharge structure, comprising:

[0010] The outer casing has a pivoting cavity;

[0011] The stator is disposed on the inner wall of the pivot cavity;

[0012] The rotor includes a rotating shaft rotatably mounted in a pivot cavity, a magnetic coil disposed in the middle of the rotating shaft, and a commutator disposed on the upper part of the rotating shaft;

[0013] An insulating base is located at the upper end of the pivot cavity. The insulating base has a guide hole that extends radially through it. A support portion extends upward from the bottom wall of the guide hole. Powder discharge channels are provided through the sides of the support portion.

[0014] The guide hole is equipped with a slidably mounted carbon brush. The lower wall of the carbon brush is in contact with the support part, and the front end of the carbon brush can switch between a position that abuts against or moves away from the wall of the commutator.

[0015] The top cover is installed above the insulating base and fixed to the upper end of the outer shell.

[0016] By improving the guide hole structure of the insulating base, by setting a support part, and by forming a powder discharge channel through the support part and the two sides of the guide hole, when the carbon brush generates carbon powder under the action of friction, the powder falls downward under the action of natural gravity and then enters the powder discharge channel. Through the reciprocating movement of the carbon brush and the rotation of the rotor, the carbon powder will be deposited in the powder discharge channel and move towards the wall of the pivot cavity, thereby avoiding the accumulation of carbon powder and improving the stability of the cooperation between the carbon brush and the commutator.

[0017] By reducing the accumulation of carbon brush powder on the commutator and carbon brush edges, the risk of wear and electrical failure is reduced, significantly extending the life of the commutator and carbon brushes, thereby improving the overall durability of the motor.

[0018] In practical applications, the commutator and carbon brushes are important components of a DC motor. They work together to ensure that the motor can rotate continuously and maintain a constant direction.

[0019] A commutator is a disc composed of multiple commutator segments made of copper or copper alloy, mounted on the rotor of a motor. Carbon brushes are conductive elements fixed to the stator of the motor, maintaining contact with the commutator surface by spring pressure.

[0020] When direct current flows through a coil, the commutator and carbon brushes work together to cause the current direction to alternate in each coil, thus generating a continuous rotating magnetic field. Specifically, when current flows through a coil, it rotates under the influence of a permanent magnet through attraction and repulsion (i.e., the switching between the S and N poles).

[0021] The lifespan of a brushed motor primarily depends on the lifespan of the commutator and carbon brushes. These two components withstand strong currents and high-load friction during motor rotation, making them the most susceptible to wear and tear, and thus the weakest points in the motor. Effectively extending the lifespan of the commutator and carbon brushes is equivalent to extending the overall lifespan of the motor, making it crucial. Attached Figure Description

[0022] Figure 1 This is an exploded view of the present invention;

[0023] Figure 2 This is a three-dimensional schematic diagram of the insulating base;

[0024] Figure 3 This is a radial sectional view of the present invention;

[0025] Figure 4 This is an axial sectional view of the present invention;

[0026] Figure 5 This is a three-dimensional schematic diagram of the present invention.

[0027] In the picture,

[0028] 1 represents the outer shell, and 10 represents the pivoting cavity.

[0029] 21 is the stator, 22 is the rotor.

[0030] 3 represents the commutator, and 30 represents the carbon brush.

[0031] 4 represents the magnetic induction coil, and 40 represents the rotating shaft.

[0032] 5 is the insulating base, 50 is the guide hole, 51 is the support part, 52 is the powder discharge channel, 53 is the notch, and 54 is the U-shaped groove.

[0033] 6 represents the top cover, and 60 represents the terminal.

[0034] 100 is the reversing clearance, and 200 is the width. Detailed Implementation

[0035] The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0036] It should be noted that if any directional indication (such as up, down, left, right, front, back, top, bottom, inside, outside, vertical, horizontal, longitudinal, counterclockwise, clockwise, circumferential, radial, axial, etc.) is involved in the embodiments of this utility model, the directional indication is only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0037] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0038] like Figures 1 to 5 As shown, a miniature DC carbon brush motor with a powder discharge structure includes:

[0039] Outer shell 1, wherein the outer shell 1 is provided with a pivot cavity 10;

[0040] Stator 21, wherein the stator 21 is disposed on the inner wall of the pivot cavity 10;

[0041] Rotor 22, the rotor 22 includes a rotating shaft 40 rotatably mounted on the pivot cavity 10, a magnetic induction coil 4 disposed in the middle of the rotating shaft 40, and a commutator 3 disposed on the upper part of the rotating shaft 40;

[0042] An insulating base 5 is located at the upper end of the pivot cavity 10. The insulating base 5 has a guide hole that extends radially through it. A support portion 51 extends upward from the bottom wall of the guide hole 50. Powder discharge channels 52 are provided through the sides of the support portion 51.

[0043] The guide hole 50 is provided with a slidably mounted carbon brush 30. The lower wall of the carbon brush 30 is in contact with the support part 51. The front end of the carbon brush 30 can switch between a position that abuts against or moves away from the wall of the commutator 3.

[0044] The upper cover 6 is installed above the insulating base 5 and fixed to the upper end of the outer shell 1.

[0045] By improving the structure of the guide hole 50 of the insulating base 5, by setting the support part 51, and by forming the powder discharge channel 52 on both sides of the support part 51 and the guide hole 50, when the carbon brush 30 generates carbon powder under the action of friction, the powder falls downward under the action of natural gravity and then to the powder discharge channel 52. Through the reciprocating movement of the carbon brush 30 and the rotation of the rotor 22, the carbon powder will be deposited in the powder discharge channel 52 and move towards the wall of the pivot cavity 10, thereby avoiding the accumulation of carbon powder and improving the stability of the cooperation between the carbon brush 30 and the commutator 3.

[0046] By reducing the accumulation of carbon brush powder on the commutator 3 and the edges of the carbon brush 30, the risk of wear and electrical failure is reduced, significantly extending the life of the commutator 3 and the carbon brush 30, thereby improving the overall durability of the motor.

[0047] In practical applications, the commutator 3 and carbon brush 30 are important components of the DC motor. They work together to ensure that the motor can rotate continuously and maintain a constant direction.

[0048] The commutator 3 is a disc composed of multiple copper or copper alloy commutator segments, mounted on the rotor 22 of the motor. The carbon brush 30 is a conductive element fixed on the stator 21 of the motor, and is kept in contact with the surface of the commutator 3 by spring pressure.

[0049] When direct current flows through the coil, the commutator 3 and carbon brush 30 work together to cause the current direction to alternate in each coil, thereby generating a continuous rotating magnetic field. Specifically, when current flows through the coil, it rotates under the influence of a permanent magnet through attraction and repulsion (i.e., switching between the S and N poles).

[0050] The lifespan of a brushed motor primarily depends on the lifespan of the commutator (3) and carbon brushes (30). These two components withstand strong current and high-load friction during motor rotation, making them the most susceptible to wear and tear, and thus the weakest points in the motor. Effectively extending the lifespan of the commutator (3) and carbon brushes (30) is equivalent to extending the overall lifespan of the motor, making it crucial.

[0051] Specifically, the commutator 3 is composed of multiple circumferentially distributed ring segments.

[0052] The commutation gap between adjacent commutator segments is 0.18 mm.

[0053] Specifically, the width of the carbon brush 30 is 2.2 mm. By improving the commutation gap and the width of the carbon brush 30, compared to the previous structure, the width of the carbon brush 30 is reduced from 2.4 mm to 2.2 mm, while the commutation gap is increased from 0.08 mm to 0.18 mm, an increase of 2.2 times. These adjustments effectively prevent transient short circuits that may occur after the carbon brush 30 wears down.

[0054] The advantages of this design are: 1. Reduced damage from welding effect: The welding effect generated during ignition will accelerate the wear of carbon brush 30 and commutator 3. Reducing the width can reduce this damage; 2. Increased commutation clearance: After reducing the width of carbon brush 30, the electrical clearance during commutation is increased, which reduces the risk of instantaneous short circuit.

[0055] These design improvements not only extend the service life of the commutator 3 and carbon brush 30, but also enhance the overall reliability and safety of the motor.

[0056] The above improvements work together to reduce the failure rate, enabling the motor to maintain excellent performance under high load or long-term operation conditions.

[0057] These advantages, achieved through optimized design, result in a dual improvement in performance and lifespan, providing a reliable guarantee for the efficient operation of brushed motors. However, large-scale deployment led to a significant number of defects.

[0058] Ensure product quality and improve customer satisfaction.

[0059] In this embodiment of the utility model, the guide hole 50 and the insulating seat 5 are integrally formed.

[0060] Specifically, the insulating seat 5 is provided with a notch 53 above the front end of the guide hole 50. In actual operation, carbon powder will also accumulate above the carbon brush 30, thereby preventing carbon powder from being deposited at the end (i.e. the wall surface that abuts against the commutator 3).

[0061] In this embodiment of the utility model, the insulating seat 5 is provided with a U-shaped groove 54 at the position above the rear of the guide hole 50, which facilitates the installation of the carbon brush 30 and also facilitates the removal of powder.

[0062] Specifically, the U-shaped groove 54 is designed to gradually increase in diameter from the axis outward, thereby improving the stability of powder discharge, which is equivalent to having a gap between the carbon brush 30 and the guide hole 50.

[0063] In this embodiment of the utility model, the upper end of the magnetic induction coil 4 is formed with terminals 60 distributed circumferentially along the rotation axis 40.

[0064] The terminal 60 abuts against the commutator 3. The structure in which the terminal 60 directly contacts the commutator 3 makes the magnetic coil 4 more compact and more stable. In particular, it can effectively ensure the stability of rotation for this miniature motor.

[0065] Specifically, the terminal 60 is bent into shape.

[0066] In this embodiment of the utility model, the insulating base 5 is embedded in the lower wall of the upper cover 6 or integrally injection molded, thereby ensuring the stability of the structure.

[0067] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A miniature DC carbon brush motor with a powder discharge structure, characterized in that, include: The outer casing has a pivoting cavity; The stator is disposed on the inner wall of the pivot cavity; The rotor includes a rotating shaft rotatably mounted in a pivot cavity, a magnetic coil disposed in the middle of the rotating shaft, and a commutator disposed on the upper part of the rotating shaft; An insulating base is located at the upper end of the pivot cavity. The insulating base has a guide hole that extends radially through it. A support portion extends upward from the bottom wall of the guide hole. Powder discharge channels are provided through the sides of the support portion. The guide hole is equipped with a slidably mounted carbon brush. The lower wall of the carbon brush is in contact with the support part, and the front end of the carbon brush can switch between a position that abuts against or moves away from the wall of the commutator. The top cover is installed above the insulating base and fixed to the upper end of the outer shell.

2. The miniature DC carbon brush motor with a powder discharge structure as described in claim 1, characterized in that: The commutator consists of multiple circumferentially distributed toroidal segments. The commutation gap between adjacent commutator segments is 0.18 mm.

3. The miniature DC carbon brush motor with a powder discharge structure as described in claim 2, characterized in that: The width of the carbon brush is 2.2 mm.

4. The miniature DC carbon brush motor with a powder discharge structure as described in claim 2, characterized in that: The guide hole is integrally formed with the insulating base.

5. The miniature DC carbon brush motor with a powder discharge structure as described in claim 4, characterized in that: The insulating base has a notch located above the front end of the guide hole.

6. The miniature DC carbon brush motor with a powder discharge structure as described in claim 4, characterized in that: The insulating seat is provided with a U-shaped groove at the upper position of the rear part of the guide hole.

7. The miniature DC carbon brush motor with a powder discharge structure as described in claim 6, characterized in that: The U-shaped groove is designed to gradually increase in diameter from the center outwards.

8. The miniature DC carbon brush motor with a powder discharge structure as described in claim 1, characterized in that: The upper end of the magnetic coil is formed with terminals distributed circumferentially along the axis of rotation. The terminal abuts against the commutator.

9. The miniature DC carbon brush motor with a powder discharge structure as described in claim 8, characterized in that: The terminal is bent into shape.

10. The miniature DC carbon brush motor with a powder discharge structure as described in claim 1, characterized in that: The insulating base is embedded in the lower wall of the upper cover or integrally injection molded.

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