A brush holder for a direct current brush motor against electromagnetic interference

Abstract

The utility model relates to a kind of for direct current brush motor anti-electromagnetic interference's brush holder, and brush holder body bottom surface is equipped with the capacitor slot for accommodating capacitor, and brush holder body top surface is equipped with the riveting groove protruding to bottom surface side, the riveting groove corresponds and forms boss at brush holder body bottom surface;The riveting groove and capacitor slot are staggered in the circumferential direction of carbon brush body, and at carbon brush holder bottom surface, the boss and capacitor slot are respectively located at the two ends of inductance in the same group EMC filter element;The capacitor slot bottom surface is equipped with the ventilation opening through the brush holder body. The above scheme changes the setting position of riveting groove, increases capacitor slot under the premise of guaranteeing riveting strength, so that it can accommodate larger specification capacitor.

Description

Technical Field

[0001] This utility model relates to the field of DC brushed motor technology, and in particular to a brush holder for resisting electromagnetic interference in DC brushed motors. Background Technology

[0002] DC brushed motors are widely used in household sewing machines, floor brushes, and other electrical appliances. The brush holder is a key component of the motor, responsible not only for transmitting current to the commutator but also for electromagnetic interference (EMC) immunity. This is typically achieved through built-in capacitors and inductors, and the EMC immunity is closely related to the size of the capacitors and inductors.

[0003] Existing brush holders have riveting grooves for riveting to the motor housing. To enhance the strength of the riveting grooves, a boss is provided at the bottom of the brush holder corresponding to the riveting groove position. In the existing technology, the capacitor slot and the boss are designed together, resulting in limited space in the capacitor slot and an inability to accommodate larger capacitors (such as JY332 and above), thus limiting the ability to resist EMC interference. In addition, because the boss structure needs to withstand the riveting pressure, ventilation openings cannot be provided in its axial area, causing toner to easily accumulate inside the carbon brush, affecting the motor's operating life and causing poor motor withstand voltage.

[0004] Furthermore, the capacitor and inductor pins that make up the EMC filter assembly need to be electrically connected, as do the inductor pins and the torsion spring pins, with the torsion spring applying rated pressure to the brushes. Existing technology uses soldering to directly connect these pins, which is labor-intensive. Moreover, during operation, motor vibration can easily cause the solder joints to detach. Utility Model Content

[0005] To address the aforementioned issues, the present invention aims to provide a brush holder for electromagnetic interference suppression in DC brushed motors. By altering the location of the riveting slot, the capacitor slot is enlarged while maintaining riveting strength, enabling it to accommodate larger capacitors.

[0006] A brush holder for electromagnetic interference suppression in a DC brushed motor includes a brush holder body, a set of brushes on the brush holder body, and a set of EMC filter elements corresponding to each brush. The EMC filter elements include an electrically connected capacitor and an inductor. The inductor is connected to the corresponding carbon brush via a torsion spring. The bottom surface of the brush holder body has a capacitor groove for accommodating the capacitor. The top surface of the brush holder body has a riveting groove protruding to one side of the bottom surface. The riveting groove forms a boss on the bottom surface of the brush holder body. The riveting groove and the capacitor groove are offset circumferentially from the carbon brush body and are located on the bottom surface of the carbon brush holder. The boss and the capacitor groove are located at the two ends of the inductor in the same set of EMC filter elements. The bottom surface of the capacitor groove has a ventilation opening penetrating the brush holder body.

[0007] In the above solution, the riveting groove and capacitor groove are staggered. The riveting groove is located at the other end of the inductor groove, between the inductor groove and the retaining ring in the circumferential direction. The reinforcing boss corresponding to the riveting groove occupies the original wiring space between the retaining ring and the capacitor on the brush holder body, without adding extra space and requiring a larger brush holder body. Furthermore, this arrangement breaks the limitation of the boss on the space of the capacitor groove in the original structure, allowing the capacitor groove to be made large enough to accommodate larger capacitors (such as JY332 and above) to improve the EMC filtering effect. Since the capacitor groove area no longer needs to bear the riveting pressure, a ventilation port can be set on the bottom of the capacitor groove to discharge toner and prevent toner accumulation.

[0008] Preferably, a first slot is provided between adjacent capacitor slots and inductor slots on the brush holder body. After the adjacent pins of the capacitor and inductor overlap in the first slot, a first electrical connection insert is inserted into the first slot to press the adjacent pins of the capacitor and inductor. A second slot is provided between adjacent inductor slots and connecting posts for mounting retaining rings on the brush holder body. After the adjacent pins of the inductor and retaining ring overlap in the second slot, a second electrical connection insert is inserted into the second slot to press the adjacent pins of the inductor and retaining ring.

[0009] The first and second electrical connection tabs are made of conductive metal. They are inserted into corresponding slots, pressing the two pins within the slot to maintain communication. Compared to soldering, this method is easier and reduces labor costs. Furthermore, the electrical connection tabs, when inserted into the slots, consistently press the corresponding pins, better withstanding the continuous vibration of the motor during operation, ensuring a reliable connection.

[0010] Preferably, the boss is disposed between the inductor slot and the connecting post, and the second slot is at least partially disposed on the boss.

[0011] At least a portion of the second slot is provided on the boss, and the second slot and the boss share the space on the brush holder body. The structure is compact, and the setting of the slot increases the concave and convex structure of the boss, which can ensure the strength of the boss.

[0012] Preferably, the terminal block is located outside the inductor and is integrally formed with the first electrical connection tab. This arrangement combines the terminal block and the electrical connection tab into a single part, simplifying the assembly process. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the brush holder structure in this application; Figure 2 for Figure 1 A structural diagram from another angle.

[0014] Figure label: The brush holder body 1, brush mounting slot 11, capacitor slot 12, inductor slot 13, connecting post 14, first slot 15, second slot 16, boss 17, riveting slot 18, vent 19, capacitor 21, inductor 22, torsion spring 3, first electrical connection plug 41, second electrical connection plug 42, and wiring terminal 43. Detailed Implementation

[0015] The embodiments of this application are described in detail below with reference to the accompanying drawings.

[0016] This embodiment relates to a brush holder for electromagnetic interference suppression in a DC brushed motor, as shown in Figures 1 and 2. The brush holder includes a brush holder body 1, with a central hole formed in the middle of the carbon brush body. A set of brushes (also called carbon brushes) are provided on the carbon brush body. In a specific embodiment, the carbon brush body has a brush mounting groove 11, and each brush is installed in the brush mounting groove 11. A set of EMC filter elements is provided for each brush. Each set of EMC filter elements includes a capacitor 21 and an inductor 22. One end of the inductor 22 is connected to the capacitor 21, and the other end is connected to the corresponding carbon brush through a torsion spring 3. The torsion spring 3 is used to apply a pressure pointing towards the commutator to the brush to ensure that the brush end face is always in close contact with the commutator surface. The working principle and connection method of the above-mentioned EMC filter elements, torsion spring 3, and brushes are conventional technical means and will not be described in detail here.

[0017] In this embodiment, the capacitor 21, inductor 22, torsion spring 3, and brush are sequentially arranged along the circumference of the brush holder body 1, corresponding to one brush. The brush holder body 1 has a capacitor slot 12 for accommodating the capacitor 21, an inductor slot 13 for accommodating the inductor 22, and a connecting post 14 for mounting the torsion spring 3, which is sleeved on the connecting post 14. Preferably, a set of brushes, capacitors 21, inductors 22, and torsion springs 3 are centrally symmetrically arranged on the brush holder body 1, which can make full use of the installation space on the brush holder.

[0018] As shown in Figure 1, the brush holder body 1 is provided with a set of riveting grooves 18. These riveting grooves 18 are used to mate with the riveting joint of the motor housing, fixing the brush holder body 1 to the iron shell. Correspondingly, a boss 17 is formed on the bottom surface of the brush holder body 1 corresponding to the riveting grooves 18. The boss 17 ensures the mechanical strength required for the riveting of the brush holder to the motor housing. Figure 2The riveting groove 18 and the capacitor groove 12 are offset circumferentially from the carbon brush body. On the bottom surface of the carbon brush holder, the boss 17 and the capacitor groove 12 are located at opposite ends of the inductor 22 in the same group of EMC filter elements. This arrangement eliminates the need for the boss 17 to occupy space in the capacitor groove 12, thus expanding the space of the capacitor groove 12 compared to existing technologies to accommodate larger capacitors (such as JY332 and above), thereby significantly improving the EMC filtering effect. Furthermore, the boss 17 is located on the other side of the inductor 22. The location of the boss 17 and the connection between the inductor 22 pins and the adjacent torsion spring 3 pins do not require additional installation space on the brush holder body 1 and do not affect the electrical connection between the inductor 22 and the torsion spring 3.

[0019] With the above configuration, since the capacitor slot 12 does not need to withstand riveting pressure, a ventilation opening 19 is provided on the bottom surface of the capacitor slot 12, penetrating the brush holder body 1. The ventilation opening 19 does not occupy additional space on the brush holder body 1 and does not affect the overall strength of the brush holder. The ventilation opening 19 provides a discharge channel for toner, which can effectively prevent toner from accumulating inside the brush holder.

[0020] As shown in Figure 2, a first slot 15 is provided between adjacent capacitor slots 12 and inductor slots 13 on the brush holder body 1. After the adjacent pins of capacitor 21 and inductor 22 overlap in the first slot 15, a first electrical connection tab 41 is inserted into the first slot 15 to press the adjacent pins of capacitor 21 and inductor 22 firmly. A second slot 16 is provided between adjacent inductor slots 13 and connecting posts 14 for mounting retaining rings on the brush holder body 1. After the adjacent pins of inductor 22 and retaining rings overlap in the second slot 16, a second electrical connection tab 42 is inserted into the second slot 16 to press the adjacent pins of inductor 22 and retaining rings firmly. In the above structure, the electrical connection tab and the slot are plugged in and engaged. The slot and the electrical connection tab are respectively provided with grooves corresponding to the pins. After the electrical connection tab is inserted into the slot, the pins in the slot can be fixed and pressed firmly through the groove engagement, so that the pins can always maintain electrical connection. Compared with the soldering method, the operation is convenient and can reduce labor costs. Furthermore, the electrical connection tab, inserted into the slot, can always press the corresponding pin firmly, and can withstand the continuous vibration during motor operation, ensuring a reliable connection. In this embodiment, the terminal 43 is located radially outside the inductor 22 and is integrally formed with the first electrical connection tab 41. This arrangement simplifies the assembly process.

[0021] In a preferred embodiment, the second slot 16 is at least partially disposed on the boss 17. For example... Figure 2As shown, the boss 17 has a functional space for installing connecting inserts, making the most of the limited space on the brush holder body 1. The overall layout of the brush holder body 1 is compact. Furthermore, the installation space and the increased concave-convex structure of the boss 17 ensure the strength of the boss 17.

[0022] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A brush holder for electromagnetic interference suppression in a DC brushed motor, comprising: a brush holder body, a set of brushes disposed on the brush holder body, and a set of EMC filter elements corresponding to each brush, wherein the EMC filter elements include an electrically connected capacitor and an inductor, the inductor being connected to the corresponding carbon brush via a torsion spring, characterized in that... The bottom surface of the brush holder body is provided with a capacitor groove for accommodating capacitors, and the top surface of the brush holder body is provided with a riveting groove protruding to one side of the bottom surface. The riveting groove forms a boss on the bottom surface of the brush holder body. The riveting groove and the capacitor groove are offset in the circumferential direction of the carbon brush body, and on the bottom surface of the carbon brush holder, the boss and the capacitor groove are respectively located at both ends of the inductor in the same group of EMC filter elements. The bottom surface of the capacitor groove is provided with a ventilation opening that runs through the brush holder body.

2. A brush holder for electromagnetic interference suppression in a DC brushed motor according to claim 1, characterized in that, A first slot is provided between adjacent capacitor slots and inductor slots on the brush holder body. After the adjacent pins of the capacitor and inductor overlap in the first slot, a first electrical connection insert is inserted into the first slot to press the adjacent pins of the capacitor and inductor. A second slot is provided between adjacent inductor slots and connecting posts for mounting retaining rings on the brush holder body. After the adjacent pins of the inductor and retaining ring overlap in the second slot, a second electrical connection insert is inserted into the second slot to press the adjacent pins of the inductor and retaining ring.

3. A brush holder for electromagnetic interference suppression in a DC brushed motor according to claim 2, characterized in that, The boss is disposed between the inductor slot and the connecting post, and the second slot is at least partially disposed on the boss.

4. A brush holder for electromagnetic interference suppression in a DC brushed motor according to claim 2, characterized in that, The wiring terminal is located on the outside of the inductor and is integrally formed with the first electrical connection plug.

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