WO2021098649A1

WO2021098649A1 - Brush electric motor, and electric brush structure thereof

Info

Publication number: WO2021098649A1
Application number: PCT/CN2020/129118
Authority: WO
Inventors: 石晶新; 赵四军; 张平满; 雷远东; 郑景超; 王修贤; 黎生都; 欧阳军军; 王挚
Original assignee: 广东德昌电机有限公司
Priority date: 2019-11-21
Filing date: 2020-11-16
Publication date: 2021-05-27
Also published as: KR20220100931A; JP2023502453A; CN211404958U

Abstract

An electric brush structure, comprising a contact surface. When the electric brush structure is arranged in an electric motor, the contact surface faces a commutator of the electric motor, the contact surface has a first end and a second end in an axial direction of the electric motor, a first flange is provided at the first end of the contact surface, a second flange is provided at the second end of the contact surface, when the electric brush structure is arranged in a direct-current electric motor, end faces of the first flange and the second flange make contact with the commutator, the first flange and the second flange are staggered with respect to a tangential direction of the direct-current electric motor, and the first flange and the second flange are respectively connected to commutator segments at both ends of a space between the commutator segments in a commutated state. According to the present invention, an electric brush makes quick contact with the adjacent next commutator segment so as to complete commutation, thereby reducing the generation of electric arcs, and preventing noise generation caused by swinging of an armature.

Description

Brush motor and its brush structure

Technical field

The present invention relates to the technical field of motors, in particular to a brushed motor.

Background technique

Motors are the most common driving mechanism in our daily lives, and are widely used in various home appliances, such as washing machines, refrigerators, mixers, etc. Generally, a motor is composed of a stator and a rotor that rotates relative to the stator. The stator is provided with brushes, and the rotor is provided with a commutator. The brushes sequentially contact and conduct each commutator segment of the commutator to energize the rotor coil, and then The magnetic field is generated and the stator acts to push the rotor to continuously rotate. In the existing motor structure, the brush swing is often caused due to the motor torque and other reasons, which in turn leads to the generation of arc noise.

technical problem

In view of this, a brush structure that can effectively avoid arc noise and a brushed motor using the brush structure are provided.

Technical solutions

In one aspect, the present invention provides a brush structure, including a contact surface, when it is built in a motor, the contact surface faces the commutator of the motor, and the contact surface has a first end and a first end along the axial direction of the motor. Two ends, the first end of the contact surface has a first flange, and the second end of the contact surface has a second flange, wherein, when built in a DC motor, the first flange and the second flange The end surface of the flange is in contact with the commutator. The first flange and the second flange are arranged staggered with respect to the tangential direction of the DC motor. In the commutation state, the first flange and the second flange are respectively connected to one of the commutator segments. The commutator segments at both ends of the interval.

Preferably, the first and second flanges are respectively formed with first and second notches, and the first and second notches make the width of the first and second flanges in the circumferential direction smaller than the contact of the brush The width of the surface in the circumferential direction.

Preferably, the width of the first and second flanges in the circumferential direction is half of the width of the contact surface of the brush in the circumferential direction.

Preferably, the first notch is opposite to the second flange in the axial direction, and the second notch is opposite to the first flange.

Preferably, the first flange and the second flange are separated by a predetermined distance in the axial direction.

On the other hand, the present invention provides a DC motor with a commutator. The commutator has a rotating shaft and a plurality of commutating segments. There is a gap between adjacent commutating segments. The DC motor includes any one of the above The brush structure is such that when the brush is built in the DC motor, the first flange and the second flange are respectively connected to the two ends of the interval between the commutating segments in the commutating state.

Preferably, it further includes a housing accommodating the stator, the rotor, and the brush structure, the housing is formed with conductive terminals, and the conductive terminals are electrically connected to the brushes.

Preferably, it further includes a conductive sheet electrically connected to each brush, a card hole is formed on the conductive sheet, a card block is formed on each brush, and the card block is inserted into the card hole.

Beneficial effect

Compared with the prior art, a gap is formed on the flange of the brush structure of the brush motor of the present invention. When the brush is commutated, the elastic conductive piece is pushed to the commutating piece to make up for the gap, so that the brush and the adjacent The next commutator piece quickly forms contact to complete the commutation, so as to reduce the generation of arcs and avoid the noise caused by the swing of the armature.

The smaller width makes the contact position and contact area of the flange and the commutator change, effectively reducing the commutation time, thereby reducing or even avoiding the generation of arcs, and avoiding vibration and noise.

Description of the drawings

Fig. 1 is a schematic structural diagram of an embodiment of a brushed motor of the present invention.

Figure 2 is an exploded view of the brushed motor shown in Figure 1.

Fig. 3 is another angle view of the rotor of the brushed motor described in Fig. 2.

Fig. 4 is a further exploded view of the brush structure and end cover of the brush motor shown in Fig. 2.

Fig. 5 is another angle view of Fig. 4.

Fig. 6 is an enlarged view of one of the brushes of the brush structure shown in Fig. 4.

Figure 7 is an assembly diagram of the brush structure and the rotor.

Fig. 8 is a top view of the brush structure and the rotor shown in Fig. 7.

Fig. 9 is a top view of a conventional brush structure and a rotor.

Embodiments of the present invention

In order to facilitate the understanding of the present invention, the present invention will be more fully described below with reference to the relevant drawings. One or more embodiments of the present invention are exemplarily given in the drawings, so as to make the understanding of the technical solutions disclosed in the present invention more accurate and thorough. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments described below.

As shown in FIGS. 1 and 2, a brush motor according to an embodiment of the present invention includes a housing 10, and a stator, a rotor 20 and a brush structure 30 arranged in the housing 10.

The housing 10 includes a housing 12 and an end cover 14 connected to the housing 12. The casing 12 is a barrel-shaped structure with an opening 120 at one end, and the end cover 14 is fixedly connected to the open end of the casing 12 and closes the casing 12. In this embodiment, a bump 140 is formed on the end cover 14, and an opening 120 is formed on the housing 12 to be plugged and fixed to the bump 140 of the end cover 14. The stator is fixed on the inner wall surface of the side wall of the housing 12 and is usually composed of N pairs of magnets with opposite polarities, where N is an integer greater than or equal to 1. In this embodiment, the magnets of the stator are a pair. A first bearing hole 122 is formed in the center of the axial end surface of the housing 12, and a second bearing hole 142 is formed in the center of the end cover 14. The first bearing hole 122 and the second bearing hole 142 are arranged coaxially . The first bearing hole 122 is provided with a first bearing 16, and the second bearing hole 142 is provided with a second bearing 18.

3, the rotor 20 includes a rotating shaft 22, a rotor core 24 and a commutator 26 fixedly sleeved on the rotating shaft 22, and a rotor core 24 and electrically connected to the commutator 26 The rotor coil (not shown). The rotating shaft 22 is a longitudinally long round rod, one end of the rotating shaft 22 passes through the first bearing 16 and extends out of the housing 12, as the output end of the brushed motor of the present invention, and is used to connect to an external load to output torque The other end of the rotating shaft 22 is pivotally connected to the second bearing 18 in rotation. The rotor core 24 is preferably made of stacked silicon steel sheets. Preferably, the surface of the rotor core 24 is covered with an insulating frame 28 to avoid short circuit of the coil. The commutator 26 is arranged coaxially with the rotor core 24 and is located on the side of the rotor core 24 facing the end cover 14. As shown in Figures 7 and 8, the commutator 26 includes a number of commutating segments 260, which are arranged evenly spaced around the rotating shaft 22, and a small portion is formed between adjacent commutating segments 260. Interval 262. Preferably, a buckle ring 29 is sleeved on the rotating shaft 22 (see FIG. 7), and the buckle ring 29 limits the commutator 26 in the axial direction.

Please refer to FIGS. 2, 4 and 5 at the same time, the brush structure 30 is fixedly arranged in the end cover 14, the end cover 14 is provided with a conductive terminal 19, and the inner end of the conductive terminal 19 is inserted into the end cover The inner part 14 is electrically connected to the brush structure 30, and the outer end is used as an external terminal of the entire motor, which extends out of the end cover 14 and is electrically connected to an external power source, thereby realizing the connection of the brush structure 30 and the external power source. The brush structure 30 includes brushes 32 arranged in pairs, and conductive sheets 34 respectively connecting the brushes 32 and the conductive terminals 19.

The conductive sheet 34 is an elastic metal sheet, which is deformed under force. Each conductive sheet 34 can be a whole-segment integrated structure, or can be a multi-segment splicing structure. In this embodiment, the conductive sheets 34 are all spliced in multiple sections. Correspondingly, a groove 144 is formed in the end cover 14, and the groove 144 matches the shape of the conductive sheet 34 to accommodate and fix the conductive sheet 34. One end of the conductive sheet 34 is connected to the inner end of the conductive terminal 19 and is electrically conducted, and the other end of the conductive sheet 34 extends out of the groove 144 to form a free end, which is connected to the brush 32 and is electrically conducted. In this embodiment, a card hole 340 is formed on the free end of the conductive sheet 34, and a protruding card block 320 is formed on the back of the brush 32. The card block 320 is inserted into the card hole 340 to hold the brush 32 is fixedly connected to the conductive sheet 34. Preferably, the conductive sheet 34 is slightly deformed initially to form a pre-tightening force, forcing the brush 32 to maintain good contact with the commutator 26.

Please refer to FIG. 6 and FIG. 7 at the same time. The two brushes 30 have the same structure and are arranged symmetrically around the commutator 26. Each brush 32 has a radially inner side surface 322 as a contact surface with the commutator 260, and the radially inner side surfaces 322 of the two brushes 32 are opposite to each other. The axial ends of the radially inner side surface 322 of each brush 32 (the upper and lower ends in FIG. 4 are marked as the first end and the second end respectively) are radially inward, that is, toward the other brush 32 protruding to form a flange is denoted as a first flange 324 and a second flange 325, and the first and second flanges 324 and 325 are in contact and conduction with the commutator 26. The first flange 324 is formed with a first notch 326, and the second flange 325 is formed with a second notch 327, so that the circumferential width of the first and second flanges 324, 325 is greatly reduced.

In this embodiment, the width of the notches 326, 327 in the circumferential direction is approximately half of the circumferential width of the flanges 324, 325. Preferably, the first and second flanges 324 of each brush 32 The positions of the first and second notches 326, 327 of 325 and 325 are different. According to the direction of FIG. 4, the first notch 326 of the first flange 324 located at the top of the brush 32 is formed on the front side of the circumferential direction of the brush 32, The second notch 327 of the second flange 325 at the bottom of the brush 32 is formed on the axial rear side of the brush 32, so that the first flange 324 at the top in the axial direction faces the second notch 327 at the bottom and the bottom The second flange 325 is directly opposite to the first notch 326 at the top, so that the contact positions of the two flanges 324, 325 of each brush 32 and the commutator 26 are staggered in the axial direction and on the tangent line without overlapping.

When the motor of the present invention is connected to an external power source through its conductive terminals 19, the rotor coils are energized through the brushes 32 and the commutator 26 to generate a magnetic field and the magnetic field of the stator magnets to drive the rotor 20 to rotate. During the rotation of the rotor 20, the brushes 32 sequentially contact and conduct with different commutator segments 260 of the commutator 26, so that different rotor coils are energized and de-energized, and the rotor 20 is continuously rotated to drive the load.

As shown in FIG. 9, the brush 32' of the existing structure forms two flanges 324' with the same structure on its upper and lower edges. The two flanges 324' serve as the running-in parts of the brush 32' and slide with the commutating piece 260. To touch. Once the brush 32' of the motor is in the commutation position, that is, the position corresponding to the interval 262 between the commutator segments 260, the brush 32' will stay on one of the commutator segments 260 and be connected to the next commutator segment next to each other. 260 forms a small gap 264. At this time, due to motor torque, brush vibration and other reasons, the brush 32' will often swing, and then a high-frequency switch will be formed between the air gap and the high-frequency arc. If the armature swing is further induced, it will be in the bushing/ The position of the rotating shaft generates arc noise and is amplified by the motor rear housing.

As shown in Figure 8, the first and second flanges 324, 325 of the brush structure 30 of the motor of the present invention are formed with first and second notches 326, 327, so that the first and second flanges 324, 325 are The tangential direction of the motor is staggered, and when the brush 32 is in the commutation position, once the first flange 324 of the brush 32 passes over the original commutating plate 260 in the first half of the circumferential direction, the gap 326 of the first flange 324 makes the upper end of the brush 32 The second half of the diverter plate 260 forms a gap with the original commutating plate 260 without support. At this time, the brush 32 is inclined, and the first flange 324 will be pushed by its elastic conductive plate 34 to the next diverting plate 260 to make up for the gap, so that The first flange 324 of the brush 32 quickly comes into contact with the adjacent next commutating piece 260, and arc extinguishing occurs between the first flange 324 and the next commutating piece 260. Compared with traditional brushes, before the entire brush passes through the commutator interval 262, the gap 264 between the brush surface and the next commutator segment 260 always exists, and high-frequency switching generates noise. During the commutation process, the next commutation piece 260 and the brush surface are physically contacted as quickly as possible to reduce the generation of arcs. Before the commutation is completed, the second flange 325 of the brush 32 is still in contact with the original commutation blade 260. When the motor is commutated, the first flange 324 and the second flange 325 are respectively connected to the commutator segments 260 at both ends of the commutator interval 262, which prompts the brush 32 to quickly complete commutating, reducing the generation of arcs and avoiding armature swinging. noise.

It should be noted that the present invention is not limited to the above-mentioned embodiments. According to the creative spirit of the present invention, those skilled in the art can also make other changes. These changes made according to the creative spirit of the present invention should all be included in the present invention. Within the scope of protection claimed by the invention.

Claims

A brush structure includes a contact surface, when it is built in a motor, the contact surface faces the commutator of the motor, and the contact surface has a first end and a second end along the axial direction of the motor. The first end of the contact surface has a first flange, and the second end of the contact surface has a second flange, wherein, when built in a DC motor, the end faces of the first flange and the second flange and The commutator is in contact, and the first flange and the second flange are arranged staggered with respect to the tangential direction of the DC motor. In the commutating state, the first flange and the second flange are respectively connected to the two spaces between the commutating segments. Commutator at the end.
The brush structure of claim 1, wherein the first and second flanges are respectively formed with first and second notches, and the first and second notches make the first and second convex The width of the rim in the circumferential direction is smaller than the width of the contact surface of the brush in the circumferential direction.
The brush structure of claim 1, wherein the width of the first and second flanges in the circumferential direction is half of the width of the contact surface of the brush in the circumferential direction.
The brush structure of claim 2, wherein the first notch is axially opposite to the second flange, and the second notch 327 is opposite to the first flange.
The brush structure of claim 1, wherein the first flange and the second flange are spaced apart by a predetermined distance in the axial direction.
A DC motor with a commutator, the commutator having a rotating shaft, a plurality of commutating segments, and a gap is provided between adjacent commutating segments. The DC motor includes the one according to any one of claims 1-5 The aforementioned brush structure makes it possible that when the brush is built into the DC motor, the first flange and the second flange are respectively connected to the two ends of the interval between the commutating segments in the commutating state.
7. The DC motor according to claim 6, further comprising a housing for accommodating the stator, rotor, and brush structure, and conductive terminals are formed on the housing, and the conductive terminals are electrically connected to the brushes. connection.
7. The DC motor according to claim 6, further comprising a conductive sheet electrically connected to each brush, a card hole is formed on the conductive sheet, a clamping block is formed on each brush, and The card block is inserted into the card hole.