48V direct current brush motor

Abstract

The utility model discloses a 48V DC brush motor comprising a housing, a stator assembly, a rotor assembly, a commutator and a carbon brush. The number of the stator assembly is an even number of stator magnetic shoes; the rotor assembly comprises a rotor shaft and a rotor iron core fixed on the periphery of the rotor shaft, wire slots are formed on the periphery of the rotor iron core at intervals, the number of the wire slots is an odd number, winding coils are filled in the wire slots clockwise, and the span of the winding coils is 3; the commutator is fixed on the periphery of the rotor shaft, the carbon brush comprises a first carbon brush and a second carbon brush, and the included angle between the first carbon brush and the second carbon brush is 90 degrees. According to the utility model, the structural arrangement of the wire ducts, the magnetic poles, the carbon brushes and the windings is optimized, and the DC brush motor which is stable in commutation and long in service life is provided.

Description

Technical Field

[0001] This utility model relates to the field of motors, and more particularly to a 48V DC brushed motor. Background Technology

[0002] Traditional brushed DC motors typically employ an even number of slots (e.g., 12 slots) paired with two- or four-pole magnets. Poor phase matching between the magnets and brushes can lead to issues such as asymmetrical electromagnetic field distribution and low winding utilization, resulting in distorted armature back electromotive force waveforms. Under high voltage or high load conditions, this often manifests as significant torque ripple, noise, large commutation sparks, poor commutation stability, rapid brush wear, strong electromagnetic interference, and short motor lifespan. Particularly with four-pole magnets paired with even-numbered slots, precise matching of pole switching and commutation phase is difficult, easily exacerbating commutation sparks and increasing brush wear rates. Simultaneously, motor vibration and noise levels are difficult to effectively suppress. Furthermore, existing carbon brushes are typically arranged at 180° (two brushes facing each other), spanning half a turn between them, resulting in coarse commutation. This not only risks failing to maintain continuous torque but can also generate severe electrical sparks under high voltage conditions.

[0003] In existing technologies, winding span is typically selected based on experience or a common number of slots (such as 12 or 24 slots), without optimization for a specific number of slots. For example, when the winding coil span is too large, it leads to an increase in the length of the winding ends and an increase in copper losses; while when the span is too small, it may reduce efficiency due to insufficient magnetic field coupling. In addition, in 48V medium-voltage scenarios, traditional span designs are prone to causing a sudden high potential difference during commutation, resulting in increased commutation sparking, erosion of the carbon brush and commutator contact surfaces, and consequently shortening the motor's lifespan.

[0004] In addition, existing motor structures mostly rely on bolts to fix the housing and end cover, which has drawbacks such as complex assembly processes and increased material costs.

[0005] Therefore, it is urgent to optimize the structural arrangement of the slots, magnetic poles, carbon brushes, and windings to provide a DC brushed motor with smooth commutation and long service life. Utility Model Content

[0006] Therefore, in order to solve the above problems, this utility model provides a 48V DC brushed motor.

[0007] This utility model is achieved through the following technical solution:

[0008] A 48V DC brushed motor includes a housing, and the housing contains:

[0009] A stator assembly includes stator magnets arranged along the inner periphery of the housing, the number of which is even.

[0010] The rotor assembly includes a rotor shaft and a rotor core fixed to the outer periphery of the rotor shaft. The outer periphery of the rotor core is provided with slots at intervals and T-shaped rotor teeth are formed between adjacent slots. The number of slots is odd and winding coils are filled in the slots in a clockwise direction. The winding coils include multiple sets of coils, and the span of each set of coils is 3.

[0011] The commutator is fixed to the outer periphery of the rotor shaft and includes several copper plates arranged circumferentially. Each copper plate has an outwardly bent copper hook at one end near the rotor core. The number of copper hooks is the same as the number of wire slots. Each group of coils has a coil terminal at the beginning and end. The coil terminals are connected to the copper hooks on the outer periphery of the commutator.

[0012] The carbon brush includes a first carbon brush and a second carbon brush. The first carbon brush and the second carbon brush are respectively disposed on the outer periphery of the commutator and respectively contact the copper hooks on the outer periphery of the commutator. The included angle between the first carbon brush and the second carbon brush is 90°.

[0013] Preferably, the stator assembly includes four levels of stator magnets, with N-pole stator magnets and S-pole stator magnets alternately distributed.

[0014] Preferably, the fourth-stage stator magnet is arranged along the inner circumference of the housing, and adjacent stator magnets are fixed together by spring clips.

[0015] Preferably, the outer periphery of the rotor core has 13 slots formed at equal angles.

[0016] Preferably, the winding coil is a wave winding coil.

[0017] Preferably, the housing includes a cylindrical housing with a rear end opening and an end cap installed at the rear end opening.

[0018] Preferably, the rear opening of the housing has multiple limiting grooves formed at equal angles along its inner circumference, and the inner side of the end cover has a ring of retaining seats. The outer diameter of the retaining seats matches the diameter of the holes in the inner circumferential wall of the housing. The outer circumference of the retaining seats also has limiting protrusions that match the limiting grooves one by one. The retaining seats are inserted into the housing from the rear opening of the housing, and the limiting protrusions are embedded in the limiting grooves one by one.

[0019] Preferably, a first bearing chamber is coaxially disposed at the front end of the housing, and a first bearing is coaxially disposed in the first bearing chamber; a second bearing chamber is coaxially disposed on the end cover, and a second bearing is coaxially disposed in the second bearing chamber; the front end of the rotor shaft is coaxially connected to the first bearing, and the rear end of the rotor shaft is coaxially connected to the second bearing.

[0020] Preferably, a first carbon brush holder and a second carbon brush holder are installed on the inner side of the end cover. The end of the commutator without the copper hook extends between the first carbon brush holder and the second carbon brush holder. The first carbon brush holder and the second carbon brush holder are respectively provided with springs at the ends away from the axis of the end cover. One end of the first carbon brush is connected to the first carbon brush holder by the spring, and the other end contacts the copper sheet on the outer periphery of the commutator. One end of the second carbon brush is connected to the second carbon brush holder by the spring, and the other end contacts the commutator.

[0021] Preferably, the first carbon brush and the second carbon brush are respectively connected to carbon brush braids on their sides, and the first carbon brush holder and the second carbon brush holder are respectively provided with clearance grooves on the side where the carbon brush braids are located. The end cap is also respectively provided with a first inductor and a second inductor, as well as a first terminal and a second terminal. The carbon brush braid of the first carbon brush is connected to the first inductor, and the first inductor is connected to the first terminal. The carbon brush braid of the second carbon brush is connected to the second inductor, and the second inductor is connected to the second terminal.

[0022] The beneficial effects of this utility model's technical solution are mainly reflected in:

[0023] 1. The rotor core adopts an asymmetrical combination of odd-numbered slots and even-numbered magnetic tiles, combined with a clockwise wave winding method with a span of 3 slots and a 90° phase carbon brush layout, which significantly improves the distribution factor of each phase winding, making the armature back EMF waveform closer to a smooth sine. The sinusoidal back EMF waveform and optimized electromagnetic force harmonic components reduce the vibration amplitude of the motor and reduce the energy of the high-frequency noise spectrum, making it particularly suitable for applications with strict requirements for quiet operation. At the same time, it improves the symmetry of the electromagnetic field, reduces iron loss and copper loss, and improves rated efficiency.

[0024] 2. The rotor core and commutator copper hooks have the same number. It is preferred to use a commutator with a 13-slot core and 13 copper hooks. Combined with a winding method with a span of 3, compared with the traditional 13-slot core arrangement, this scheme has a finer commutation. The current change and mechanical angle change triggered by each commutation are greatly reduced, making the commutation process smoother and reducing the angle range of the brush instantaneous closing short circuit.

[0025] 3. A 90° angle is formed between the two carbon brushes to ensure that the commutator switches the current direction when the rotor rotates to a position perpendicular to the magnetic field, thereby improving commutation sensitivity, enhancing spark suppression, reducing wear rate of carbon brushes and commutator, and extending life.

[0026] 4. The uniform magnetomotive force distribution of the quadrupole magnet and the 90° phase difference of the carbon brush form a precise commutation timing match, which can suppress the intensity of commutation sparks, reduce the wear rate of the carbon brush and commutator contact surface, significantly extend the service life of the motor, and the improvement of magnetic balance reduces the current demand under rated operating conditions, and reduces energy consumption at the same output power, meeting the design requirements of high-efficiency electromechanical systems.

[0027] 5. The motor housing and end cover are fixed together by pressure fitting through their own limiting structure, eliminating the need for machining holes and fasteners required by traditional bolt connections, improving assembly efficiency, and reducing overall manufacturing costs. The multi-layer limiting structure also helps to improve the stability and sealing performance of the motor housing structure installation. Attached Figure Description

[0028] Figure 1 It is a first-person perspective 3D view of a 48V DC brushed motor;

[0029] Figure 2 This is a 3D view of a 48V DC brushed motor from a second-angle perspective (machine casing omitted);

[0030] Figure 3 This is a schematic diagram of the connection structure inside the end cap;

[0031] Figure 4 This is a top view of a 48V DC brushed motor from a second perspective (end cap omitted);

[0032] Figure 5 This is a cross-sectional view of a 48V DC brushed motor from a second-angle perspective.

[0033] Figure 6 yes Figure 5 Enlarged view of section A;

[0034] Figure 7 This is a top view showing the connection status between the rotor core and the commutator.

[0035] Figure 8 Reference in Example 1 Figure 7 A diagram showing the numbering of the cable tray and the copper hook;

[0036] Figure 9 This is a schematic diagram showing the connection positions of the winding coil, the wire groove, and the copper hook in Example 1. Detailed Implementation

[0037] To make the objectives, advantages, and features of this utility model clearer and more detailed, the following non-limiting description of preferred embodiments will be illustrated and explained. These embodiments are merely typical examples of applying the technical solutions of this utility model; any technical solutions formed by equivalent substitutions or equivalent transformations fall within the scope of protection claimed by this utility model.

[0038] It should also be stated that, in the description of the solution, the terms "center", "upper", "lower", "left", "right", "front", "rear", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of description and simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0039] Furthermore, the terms "first" and "second" in this solution are used for descriptive purposes only and should not be construed as indicating or implying a ranking of importance, or implicitly specifying the number of technical features shown. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In this utility model, "multiple" means two or more, unless otherwise explicitly specified.

[0040] This utility model discloses a 48V DC brushed motor, such as Figures 1-7 As shown, the system includes a housing, within which are disposed: a stator assembly, a rotor assembly, a commutator 5, and carbon brushes, wherein:

[0041] The stator assembly includes stator magnetic tiles 1 arranged along the inner periphery of the housing. The number of stator magnetic tiles 1 is even. The stator magnetic tiles 1 include N-pole stator magnetic tiles 1 and S-pole stator magnetic tiles 1, which are alternately distributed to form a continuous closed magnetic circuit inside the stator.

[0042] The rotor assembly includes a rotor shaft 2 and a rotor core 3 fixed to the outer periphery of the rotor shaft 2. The outer periphery of the rotor core 3 is provided with slots 301 spaced apart, and T-shaped rotor teeth 302 are formed between adjacent slots 301. The number of slots 301 is odd, and winding coils 4 are filled in the slots 301 in a clockwise direction. The winding coils 4 preferably adopt a wave winding method, and the winding coils 4 are composed of multiple groups of coils. The span of each group of coils is 3, that is, the starting and ending sides of each group of coils pass through 3 slots 301 to form a wave-shaped path. The protruding rotor teeth 302 between two slots 301 are used to support the winding coils 4 and separate different groups of coils. After the rotor core 3 and the winding coils 4 are assembled, the rotor assembly is formed, and the rotor assembly is installed in the housing.

[0043] The commutator 5 is fixed to the outer periphery of the rotor shaft 2 and includes several copper sheets arranged circumferentially. Each copper sheet has an outwardly bent copper hook 501 at one end near the rotor core 3. The number of copper hooks 501 is the same as the number of wire slots 301. Each group of coils in the winding coil 4 has a coil terminal at its starting end and ending end, and the coil terminal is connected to the copper hooks 501 on the outer periphery of the commutator 5. The leads of each group of coils are welded / pressed onto the copper hooks 501 of the commutator 5 in a specific order. Specifically, the coil terminal at the starting end of each group of coils is welded / pressed onto one of the copper hooks 501, and the coil terminal at the ending end is welded / pressed onto adjacent or spaced-apart copper hooks 501. The tension of the winding coil 4 is controlled to ensure that the winding coil 4 does not loosen. Through this connection, the winding is divided into multiple circuits, so that the current direction automatically switches when the commutator 5 rotates.

[0044] like Figure 3 , Figure 4 As shown, the carbon brush includes a first carbon brush 6 and a second carbon brush 7. The first carbon brush 6 and the second carbon brush 7 are respectively disposed on the outer periphery of the commutator 5 and respectively contact the copper hook 501 on the outer periphery of the commutator 5. The included angle between the first carbon brush 6 and the second carbon brush 7 is 90°. Since ideal commutation occurs when the armature winding is in the neutral plane, the winding does not cut the main magnetic field, the induced electromotive force is zero, and the neutral plane corresponds to the position where the rotor magnetic field is perpendicular to the stator magnetic field. At this time, the commutation current changes slowly, the voltage difference between the carbon brush and the commutator segment is the smallest, and the spark is the weakest. Therefore, by setting a 90° included angle between the two carbon brushes, it is ensured that the commutator 5 switches the current direction when the rotor assembly rotates to the position where the magnetic field is perpendicular, thereby suppressing the intensity of commutation spark.

[0045] like Figure 8 , Figure 9 As shown, in Embodiment 1, the stator assembly includes four-stage stator magnets 1, with N-pole and S-pole stator magnets 1 alternately distributed. The outer periphery of the rotor core 3 has 13 slots 301 formed at equal angles; therefore, the number of copper hooks 501 in the commutator 5 is also 13. The winding coil 4 includes two layers of coil groups (i.e., two turns of coil), each layer of coil group wrapping around the rotor core 3 once. Each layer of coil includes 5 coil groups, and each coil group has coil terminals at both its starting and ending ends. (Reference) Figure 8 , Figure 9 The connection relationships between the coil terminals of each group of coils in winding coil 4 and each copper hook 501 of commutator 5, as well as the connection relationships between each group of coils and each slot 301, are shown in Table 1 below: Table 1: Connection positions of each group of coils in rotor core 3 and their connection relationships with copper hooks 501 of commutator 5 in Example 1:

[0046] turn number Circle number Start Slot pair Out of slot pair termination 1 1 1 hook 3-channel 13 cable trays 4 hooks 1 2 4 hooks 6-channel 3-channel 7 hooks 1 3 7 hooks 9-channel 6-channel 10 hooks 1 4 10 hooks 12 cable trays 9-channel 13 hooks 1 5 13 hooks 2 cable trays 12 cable trays 1 hook 2 1 6 hooks 8-channel 5-channel 9 hooks 2 2 9 hooks 11 cable trays 8-channel 12 hooks 2 3 12 hooks 1 cable tray 11 cable trays 2 hooks 2 4 2 hooks 4-channel 1 cable tray 5 hooks 2 5 5 hooks 7-channel 4-channel 6 hooks

[0047] The first embodiment is a preferred embodiment of the present invention. In other embodiments, the connection relationship between the winding coil 4, the commutator 5, and the slot 301 can be adjusted according to actual needs, which will not be elaborated here.

[0048] like Figure 2 , Figure 4 As shown, when a four-stage stator magnet 1 is provided, the four-stage stator magnet 1 is arranged along the inner circumference of the housing, and adjacent stator magnet 1 are fixed by spring clips 21 to form a ring of stator assembly around the inner circumference of the housing. At the same time, the rotor assembly is installed at intervals on the inner circumference of the stator assembly.

[0049] like Figures 1-6 As shown, in some embodiments, the housing includes a cylindrical housing 16 with a rear end opening and an end cap 18 installed at the rear end opening. Multiple limiting grooves 1601 are formed at equal angles along the inner circumference of the rear end opening of the housing 16. A ring of retaining seats 1801 is formed on the inner side of the end cap 18. The outer diameter of the retaining seats 1801 matches the diameter of the hole in the inner circumferential wall of the housing 16. Limiting bosses 1802 are also formed on the outer circumference of the retaining seats 1801, each matching one of the limiting grooves 1601. The retaining seats 1801 are inserted into the housing 16 from the rear end opening, and the limiting bosses 1802 are embedded into the limiting grooves 1601, thereby fixing the end cap 18 to the housing 16.

[0050] like Figures 2-5 As shown, in one embodiment, a first bearing chamber 17 is coaxially disposed at the front end of the housing 16. The first bearing chamber 17 is preferably integrally disposed with the housing 16. In some embodiments, the first bearing chamber 17 and the housing 16 may also be detachable structures, which will not be elaborated here. A first bearing 19 is coaxially disposed in the first bearing chamber 17. A second bearing chamber 22 is coaxially disposed on the end cover 18. A second bearing 20 is coaxially disposed in the second bearing chamber 22. The front end of the rotor shaft 2 is coaxially connected to the first bearing 19, and the rear end of the rotor shaft 2 is coaxially connected to the second bearing 20, thereby coaxially fixing the rotor shaft 2 in the motor housing. At the same time, the mover core, winding coil 4 and commutator 5 on the rotor shaft 2 are also fixed in the motor housing.

[0051] like Figures 2-5As shown, in one embodiment, a first carbon brush holder 8 and a second carbon brush holder 9 are installed on the inner side of the end cover 18. The inner side of the end cover 18 refers to the side where the end cover 18 is connected to the housing 16. The end of the commutator 5 without the copper hook 501 extends between the first carbon brush holder 8 and the second carbon brush holder 9. The first carbon brush holder 8 and the second carbon brush holder 9 have openings at both ends, one end facing the commutator 5 and the other end away from the commutator 5. The first carbon brush holder 8 and the second carbon brush holder 9 are respectively provided with springs 10 at the ends away from the axis of the end cover 18. One end of the first carbon brush 6 is connected to the first carbon brush holder 8 through the spring 10, and the other end contacts the copper sheet on the outer periphery of the commutator 5. One end of the second carbon brush 7 is connected to the second carbon brush holder 9 through the spring 10, and the other end contacts the commutator 5.

[0052] like Figure 3 As shown, the first carbon brush 6 and the second carbon brush 7 are respectively connected to carbon brush braids 11 on their sides. The first carbon brush holder 8 and the second carbon brush holder 9 are respectively provided with clearance grooves on the side where the carbon brush braids 11 are located. The clearance grooves are strip-shaped grooves, thereby ensuring that the clearance grooves on the sides of the first carbon brush holder 8 and the second carbon brush holder 9 can avoid the carbon brush braids 11 during the movement of the first carbon brush 6 and the second carbon brush 7. The end cap 18 is also provided with a first inductor 12 and a second inductor 13, as well as a first terminal 14 and a second terminal 15. The carbon brush braid 11 of the first carbon brush 6 is connected to the first inductor 12, and the first inductor 12 is connected to the first terminal 14. The carbon brush braid 11 of the second carbon brush 7 is connected to the second inductor 13, and the second inductor 13 is connected to the second terminal 15. One of the first terminal 14 and the second terminal 15 is a positive terminal and the other is a negative terminal. The first terminal 14 and the second terminal 15 are connected to an external power supply, and the external current forms a closed loop between the two terminals and the two carbon brushes, the commutator 5 and the winding coil 4.

[0053] This utility model has many other embodiments. All technical solutions formed by equivalent transformation or equivalent transformation fall within the protection scope of this utility model.

Claims

A 1.48V DC brushed motor, including a housing, characterized in that: The housing contains: A stator assembly includes stator magnets arranged along the inner periphery of the housing, wherein the number of stator magnets is even. The rotor assembly includes a rotor shaft and a rotor core fixed to the outer periphery of the rotor shaft. The outer periphery of the rotor core is provided with slots at intervals and T-shaped rotor teeth are formed between adjacent slots. The number of slots is odd and winding coils are filled in the slots in a clockwise direction. The winding coils include multiple sets of coils, and the span of each set of coils is 3. The commutator is fixed to the outer periphery of the rotor shaft and includes several copper plates arranged circumferentially. Each copper plate has an outwardly bent copper hook at one end near the rotor core. The number of copper hooks is the same as the number of wire slots. Each group of coils has a coil terminal at the beginning and end. The coil terminals are connected to the copper hooks on the outer periphery of the commutator. The carbon brush includes a first carbon brush and a second carbon brush. The first carbon brush and the second carbon brush are respectively disposed on the outer periphery of the commutator and respectively contact the copper hooks on the outer periphery of the commutator. The included angle between the first carbon brush and the second carbon brush is 90°.

2. The 48V DC brushed motor according to claim 1, characterized in that: The stator assembly includes four levels of stator magnets, with N-pole stator magnets and S-pole stator magnets alternately distributed.

3. The 48V DC brushed motor according to claim 2, characterized in that: The four-stage stator magnets are arranged along the inner circumference of the housing, and adjacent stator magnets are fixed together by spring clips.

4. The 48V DC brushed motor according to claim 2, characterized in that: The outer periphery of the rotor core has 13 slots formed at equal angles.

5. The 48V DC brushed motor according to claim 4, characterized in that: The winding coil is a wave winding coil.

6. The 48V DC brushed motor according to claim 5, characterized in that: The housing includes a cylindrical casing with an opening at the rear end, and an end cap is installed at the rear end opening.

7. The 48V DC brushed motor according to claim 6, characterized in that: The rear opening of the housing has multiple limiting grooves formed at equal angles along its inner circumference. A ring of retaining seats is formed on the inner side of the end cover. The outer diameter of the retaining seats matches the diameter of the holes in the inner circumferential wall of the housing. The outer circumference of the retaining seats also has limiting protrusions that match the limiting grooves one by one. The retaining seats are inserted into the housing from the rear opening of the housing, and the limiting protrusions are embedded into the limiting grooves one by one.

8. The 48V DC brushed motor according to claim 6, characterized in that: The front end of the housing is coaxially provided with a first bearing chamber, and a first bearing is coaxially provided in the first bearing chamber. The end cover is coaxially provided with a second bearing chamber, and a second bearing is coaxially provided in the second bearing chamber. The front end of the rotor shaft is coaxially connected to the first bearing, and the rear end of the rotor shaft is coaxially connected to the second bearing.

9. The 48V DC brushed motor according to claim 6, characterized in that: The inner side of the end cover is equipped with a first carbon brush holder and a second carbon brush holder. The end of the commutator without the copper hook extends between the first carbon brush holder and the second carbon brush holder. The first carbon brush holder and the second carbon brush holder are respectively provided with springs at the ends away from the axis of the end cover. One end of the first carbon brush is connected to the first carbon brush holder through the spring, and the other end contacts the copper sheet on the outer periphery of the commutator. One end of the second carbon brush is connected to the second carbon brush holder through the spring, and the other end contacts the commutator.

10. The 48V DC brushed motor according to claim 9, characterized in that: The first carbon brush and the second carbon brush are respectively connected to carbon brush braids on their sides. The first carbon brush holder and the second carbon brush holder are respectively provided with clearance grooves on the side where the carbon brush braids are located. The end cap is also respectively provided with a first inductor and a second inductor, as well as a first terminal and a second terminal. The carbon brush braid of the first carbon brush is connected to the first inductor, and the first inductor is connected to the first terminal. The carbon brush braid of the second carbon brush is connected to the second inductor, and the second inductor is connected to the second terminal.

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