Reciprocating rotation motor with low positioning force

Abstract

The utility model discloses a reciprocating rotation motor with low positioning force, which comprises a rotor part and a stator part, the rotor part comprises a rotating shaft and an iron core sleeved on the rotating shaft, the stator part comprises a casing and a magnetic steel assembly arranged on the inner wall of the casing, the magnetic steel assembly comprises first magnetic steel and second magnetic steel, the magnetic polarities of the first magnetic steel and the second magnetic steel are opposite, and the iron core comprises at least one tooth part. A group of magnetic steel components corresponding to each tooth part are arranged on the inner wall of the casing, the tooth parts face the space between the first magnetic steel and the first magnetic steel of the corresponding magnetic steel components at the initial position, and when the motor rotates clockwise or anticlockwise, the distance between the tooth parts and the corresponding first magnetic steel and / or the distance between the first magnetic steel tends to be decreased first and then increased; in this way, non-uniform air gaps are formed between the magnetic steel and the tooth parts in the rotating process, the cogging torque of the rotor is relatively small within a certain deflection angle, the cogging torque can be obviously increased when the deflection angle of the rotor is larger than a preset angle, the damping effect is achieved, and collision between the rotor and physical limiting is avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to motor field, concretely relates to a low positioning force reciprocating rotation motor. BACKGROUND

[0002] Electric toothbrushes are becoming more and more popular, and the number of users is also increasing. In order to meet market requirements, electric toothbrush manufacturers have introduced more action modes. For example, by inputting different frequency / duty cycle signals at both ends of the motor, the swing angle and speed of the motor can be adjusted. Even the motor action can be controlled by inputting a combination of signals. For example, when the motor is vibrating at 260 Hz, a 2 Hz swing signal is input at the same time, so that the brush head vibrates at a certain angle range, both fast (260 Hz) and slow (2 Hz). As a reciprocating rotation motor controlled by the motor, the smaller the self-positioning torque of the motor, the better the control. However, the swing amplitude of the brush head is not the larger the better. If it is too large, it is easy to hurt the gums, resulting in a decrease in user experience. Therefore, physical limits are often set inside the motor to limit the output swing angle of the motor within a safe range. However, when the user brushes his teeth with excessive deflection and the self-positioning torque of the motor is small, the rotor is easy to deflect. When the rotor deflects and hits the physical limit, high-frequency impact occurs, resulting in noise. This noise brings a bad experience to the user. SUMMARY

[0003] In view of this, in order to solve the problem of noise caused by high-frequency impact when the rotor hits the physical limit, the utility model provides a low-positioning-force reciprocating rotation motor. The reciprocating rotation motor can increase the self-positioning torque before the rotor deflects to the physical limit, thereby limiting the swing amplitude of the rotor and avoiding the noise problem caused by the collision between the rotor and the physical limit.

[0004] The technical scheme is as follows: a low-positioning-force reciprocating rotation motor, the reciprocating rotation motor comprises a rotor part and a stator part matched with each other, wherein the rotor part comprises a rotating shaft and an iron core sleeved on the rotating shaft, the stator part comprises a machine shell and a magnetic steel assembly arranged on the inner wall of the machine shell, each group of the magnetic steel assembly comprises a first magnetic steel and a second magnetic steel, and the magnetic polarities of the two are opposite, wherein:

[0005] At least one tooth part is arranged on the iron core, and a group of the magnetic steel assembly is arranged on the inner wall of the machine shell corresponding to each tooth part. In the initial position, the tooth part faces between the first magnetic steel and the second magnetic steel of the corresponding magnetic steel assembly;

[0006] When rotating clockwise or counterclockwise, the distance between the tooth part and the corresponding first magnetic steel and / or second magnetic steel shows a trend of first decreasing and then increasing.

[0007] The material of the iron core and the tooth part is the same.

[0008] With the above technical scheme, at the initial position, the magnetic steel assembly of the stator part and the iron core of the rotor part generate self-positioning torque under the magnetic force to position the rotor at the initial balance position, when reciprocating rotation, the distance between the iron core and the first magnetic steel and / or the second magnetic steel changes, so that there is a non-uniform air gap between the magnetic steel and the tooth part during rotation, so that the rotor has a relatively small cogging torque within a certain deflection angle, and the cogging torque will be significantly increased when the deflection angle of the rotor is greater than the preset angle. Thus, the swing amplitude of the rotor can be effectively controlled, and the damping effect is achieved, avoiding impact between the physical limit and avoiding the bad experience caused by impact noise.

[0009] Preferably, the rotating shaft reciprocates clockwise and counterclockwise within a preset angle, and compared with the magnetic slot torque at the initial position, when the rotating shaft rotates clockwise or counterclockwise by more than half of the preset angle, the magnetic slot torque between the tooth part and the corresponding first magnetic steel and / or first magnetic steel increases by no less than 100%. When the rotor deflection angle is greater than 50% of the preset angle, the sudden increase in the magnetic slot torque is preferably no less than 100% compared with the magnetic slot torque at the initial position. For example, the magnetic slot torque is about 80 gf·cm at the initial position, and when the rotor deflection angle is greater than the preset angle, the cogging torque is no less than 160 gf·cm, and when the rotating shaft rotates to the preset angle, the magnetic slot torque is generally no more than 100 gf·cm.

[0010] Preferably, the rotating shaft reciprocates between 20-30° clockwise and 20-30° counterclockwise.

[0011] Preferably, the tooth part includes a tooth root part for fixing on the iron core, and a tooth top part connected with the tooth root part, wherein a coil winding is wound on the tooth root part;

[0012] A separation groove is provided on the top surface of the tooth top part, and at the initial position, the groove opening of the separation groove faces the middle of the first magnetic steel and the second magnetic steel of the corresponding magnetic steel assembly. With this structure, the tooth part always remains at the initial position in the unpowered state through the separation groove.

[0013] Preferably, with the center line of the groove bottom surface of the separation groove as a first boundary line, from the direction close to the first boundary line to the direction away from the first boundary line, the distance between the top surface of the tooth top part and the axis of the iron core increases first and then decreases. This scheme provides a scheme that can effectively control the air gap change between the tooth part and the corresponding magnetic steel, and can effectively avoid the generation of impact noise.

[0014] Preferably, the top surface of the tooth top part includes a first surface, a second surface and a third surface;

[0015] The two sides of the first surface are sequentially connected with the second surface and the third surface respectively, the second surface is a circular arc surface concentric with the iron core, and the first surface and the third surface are located in the circle of the second surface.

[0016] Preferably, the first surface is a concave arc surface, and the concave part forms the separation groove.

[0017] Preferably, the third surface is a plane or a curved surface.

[0018] Preferably, the first surface and the second surface are connected through a smooth curved surface.

[0019] Preferably, the center line between the first magnetic steel and the second magnetic steel of the same group of magnetic steel assemblies is a second boundary line, and from the direction close to the second boundary line to the direction away from the second boundary line, the distance between the surface of the first magnetic steel and the second magnetic steel facing the tooth part and the inner wall of the shell shows an increasing trend. This scheme provides a new way to control the air gap between the tooth part and the magnetic steel. This scheme not only can obtain good noise reduction effect, but also is beneficial to save the use amount of magnetic steel.

[0020] In other words, the center line between the first magnetic steel and the second magnetic steel of the same group of magnetic steel assemblies is a second boundary line, and from the direction close to the second boundary line to the direction away from the second boundary line, the thickness of the first magnetic steel and the second magnetic steel shows an increasing trend.

[0021] Preferably, the surface of the first magnetic steel and the second magnetic steel facing the tooth part comprises a fourth surface and a fifth surface spliced together, wherein the fourth surface is close to the second boundary line, and from the direction close to the second boundary line to the direction away from the second boundary line, the distance between the fourth surface and the inner wall of the shell shows a gradually increasing trend, and the distance between the fifth surface and the inner wall of the shell remains stable.

[0022] Compared with the prior art, the utility model has the beneficial effects that: when reciprocating rotation, the distance between the iron core and the first magnetic steel and / or the first magnetic steel changes, so that there is a non-uniform air gap between the magnetic steel and the tooth part during rotation, so that the rotor has a relatively small cogging torque within a certain deflection angle, and the cogging torque will be significantly improved when the rotor deflection angle is greater than the preset angle, so that the swing amplitude of the rotor can be effectively controlled, a damping effect is achieved, impact between the physical limit is avoided, and the adverse experience caused by impact noise is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a structure schematic view of the reciprocating rotation motor of example 1.

[0024] Figure 2 is a sectional view of A-A of Figure 1

[0025] Figure 3 is a structural schematic view of a tooth portion;

[0026] Figure 4 is a structural schematic view of an internal structure of a reciprocating rotation motor of Example 1;

[0027] Figure 5 is a first state schematic view of counterclockwise rotation of the reciprocating rotation motor of Example 1;

[0028] Figure 6 is a second state schematic view of counterclockwise rotation of the reciprocating rotation motor of Example 1;

[0029] Figure 7 is a structural schematic view of an internal structure of a reciprocating rotation motor of Example 2. DETAILED DESCRIPTION

[0030] The present application will be further described below in conjunction with the embodiments and the accompanying drawings.

[0031] In the description of the present application, it is to be understood that the terms "upper", "lower", "vertical", "horizontal", "top", "bottom", and the like are used to indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0032] The terms "first", "second", "third", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features referred to, so that the features with "first", "second", "third" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0033] In the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0034] Example 1

[0035] ​As Figures 1-4 shown in the figure, a low-positioning-force reciprocating rotary motor, comprising a rotor part and a stator part matched with each other, wherein the rotor part comprises a rotating shaft 5 and a core 6 sleeved on the rotating shaft 5, and the stator part comprises a casing 2 and a magnetic steel assembly 4 arranged on the inner wall of the casing 2, each of the magnetic steel assembly 4 comprises a first magnetic steel 4a and a second magnetic steel 4b, and the magnetic polarities of the two are opposite to the surface of the rotor part, wherein:

[0036] At least one tooth part 6a is arranged on the core 6, and a set of the magnetic steel assembly 4 is arranged on the inner wall of the casing 2 corresponding to each tooth part 6a, and the tooth part 6a is located between the first magnetic steel 4a and the second magnetic steel 4b of the corresponding magnetic steel assembly 4 in the initial position.

[0037] When rotating clockwise or counterclockwise, the distance between the tooth part 6a and the corresponding first magnetic steel 4a and / or second magnetic steel 4b shows a trend of first decreasing and then increasing.

[0038] The rotating shaft 5 reciprocates clockwise and counterclockwise within a preset angle, specifically, the rotating shaft 5 reciprocates between 20-30° clockwise and 20-30° counterclockwise, compared with the magnetic slot torque in the initial position, when the rotating shaft 5 rotates clockwise or counterclockwise by more than 50% of the preset angle, the magnetic slot torque between the tooth part 6a and the corresponding first magnetic steel 4a and / or second magnetic steel 4b increases by no less than 100%, and such change can be achieved by controlling the air gap size between the tooth top part 6a2 and the corresponding first magnetic steel 4a and / or second magnetic steel 4b.

[0039] Specifically, the tooth part 6a comprises a tooth root part 6a1 for fixing on the core 6, and a tooth top part 6a2 connected with the tooth root part 6a1, and the core, the tooth root part 6a1 and the tooth top part 6a2 are integrally formed, wherein a coil winding 8 is wound on the tooth root part 6a1, and the tooth part 6a generates a magnetic field on the tooth top part 6a2 after the coil winding 8 is electrified, and the magnetic field interacts with the magnetic steel assembly 4, thereby pushing the rotor part to rotate.

[0040] As Figure 2 shown in the figure, a top surface of the tooth top part 6a2 is provided with a separation groove 6a3, and in the initial position, a groove opening of the separation groove 6a3 is located between the first magnetic steel 4a and the second magnetic steel 4b of the corresponding magnetic steel assembly 4.

[0041] Taking the center line of the groove bottom surface of the separation groove 6a3 as a first boundary line, from the direction close to the first boundary line to the direction away from the first boundary line (i.e. from the middle to the left and right directions), the distance between the top surface of the tooth top part 6a2 and the axis of the core 6 shows a trend of first increasing and then decreasing.

[0042] The top surface of the tooth tip 6a2 includes a first surface 6a201, a second surface 6a202, and a third surface 6a203. The second surface 6a202 and the third surface 6a203 are connected sequentially to the two sides of the first surface 6a201. The second surface 6a202 is an arc surface concentric with the iron core 6. The first surface 6a201 and the third surface 6a203 are both located inside the circle containing the second surface 6a202.

[0043] The first surface 6a201 is a concave arc-shaped surface, and its concave part forms the dividing groove 6a3. The opening of the dividing groove 6a3 faces the middle of the corresponding first magnet 4a and second magnet 4b.

[0044] The third surface 6a203 is a plane or a curved surface, and the first surface 6a201 and the second surface 6a202 are connected by a smooth curved transition.

[0045] When the tooth 6a has the first surface 6a201, the second surface 6a202, and the third surface 6a203, the thickness of the first magnet 4a and the second magnet 4b is uniform, and the surfaces of the two facing the corresponding tooth 6a are arc surfaces. The center of the arc surface is concentric with the iron core 6. The change in the size of the air gap between the tooth 6a and the corresponding first magnet 4a and / or second magnet 4b is achieved by the change of the first surface 6a201, the second surface 6a202, and the third surface 6a203.

[0046] The reciprocating motor provided in this embodiment includes two symmetrically arranged teeth 6a, the first magnets 4a of the two sets of magnet assemblies 4 facing each other, and the second magnets 4b of the two sets of magnet assemblies 4 facing each other. When rotating counterclockwise, as... Figure 2 As shown, the distance between the upper tooth 6a and the corresponding first magnet 4a shows a trend of first decreasing and then increasing, and the distance between the lower tooth 6a and the corresponding second magnet 4b also shows a trend of first decreasing and then increasing.

[0047] like Figure 4 As shown, the reciprocating motor further includes: an end cover 12, the housing 2 is a cylindrical shape with one end open, the open end of which is closed by the end cover 12, a first bearing 11 is provided inside the end cover 12, a second bearing 1 is provided at the other end of the housing 2, the rotating shaft 5 is inserted into the first bearing 11 and the second bearing 1, and one end of the rotating shaft 5 extends out of the housing 2 to form an output end.

[0048] The iron core 6 and the tooth portion 6a are coated with an insulating coating 7, the casing 2 has a waist-shaped cross section, two opposite walls of which are circular arc-shaped, and the other two opposite walls are planar, the end frame 3 is mounted on the inner wall of the casing 2, the magnetic steel grooves are formed in the end frame 3, the first magnetic steel 4a and the second magnetic steel 4b are respectively mounted in the corresponding magnetic steel grooves, and the first magnetic steel 4a and the second magnetic steel 4b are both attached to the circular arc-shaped wall of the casing 2, the end frame 3 is matched with the casing 2 in shape, the physical limiting protrusion is arranged on the planar wall of the end frame 3, the physical limiting protrusion is used to limit the maximum rotation angle of the rotating part to be not more than 30°, preferably 20-30°, so as to avoid that the rotor part cannot return to the initial position due to too large swing angle.

[0049] From Figure 4 It can also be seen that the commutator 9 is further mounted on one end of the rotating shaft 5 close to the end cover 12, at least one positioning groove is formed in the end face of the iron core 6 close to the commutator 9, the positioning protrusion is correspondingly arranged on the commutator 9, the positioning protrusion on the commutator 9 is inserted into the corresponding positioning groove, and the brush 10 is further arranged in the end cover 12, and the commutator 9 is connected with the brush 10.

[0050] In some embodiments, when the reciprocating rotating motor includes one tooth portion 6a, when counterclockwise rotating, the distance between the tooth portion 6a and the corresponding first magnetic steel 4a shows a trend of first decreasing and then increasing, and when clockwise rotating, the distance between the tooth portion 6a and the corresponding second magnetic steel 4b shows a trend of first decreasing and then increasing.

[0051] Other components or connections not specifically mentioned are conventional settings in the art, which will not be described here.

[0052] Taking counterclockwise rotation as an example, the rotating process of the reciprocating rotating motor provided in the embodiment is as shown in Figure 5 and 6 , wherein Figure 5 is a state diagram when the rotating angle of the rotating shaft 5 reaches 50% of the preset angle (the dashed circle in the figure is the circle where the second face 6a202 is located), at this time, compared with the magnetic slot torque at the initial position, the magnetic slot torque will be significantly improved, Figure 6 is a state diagram when the rotating angle of the rotating shaft 5 reaches the preset angle, at this time, the magnetic slot torque decreases.

[0053] Embodiment 2

[0054] As shown in Figure 7 , the difference between the embodiment and embodiment 1 is only that:

[0055] The center line between the first magnetic steel 4a and the second magnetic steel 4b of the same set of magnetic steel assemblies 4 is taken as a second demarcation line, and the distance from the surface of the tooth portion 6a to the inner wall of the casing 2 increases from the direction close to the second demarcation line to the direction away from the second demarcation line.

[0056] The surface of the first magnetic steel 4a and the second magnetic steel 4b towards the tooth portion 6a includes a fourth surface 401 and a fifth surface 402 spliced together, wherein the distance from the fourth surface 401 to the inner wall of the casing 2 increases gradually from the direction close to the second demarcation line to the direction away from the second demarcation line, and the distance from the fifth surface 402 to the inner wall of the casing 2 remains stable.

[0057] In other words, the thickness of the first magnetic steel 4a and the second magnetic steel 4b increases from the direction close to the second demarcation line to the direction away from the second demarcation line, specifically, the thickness increases gradually at first and then remains stable.

[0058] When the first magnetic steel 4a and the second magnetic steel 4b have the fourth surface 401 and the fifth surface 402, the tooth surface of the tooth top portion 6a2 is a circular arc surface, the center of which is concentric with the iron core 6, and the tooth surface of the tooth top portion 6a2 is provided with a separation groove 6a3, and the slot opening of the separation groove 6a3 is towards the middle of the corresponding first magnetic steel 4a and the second magnetic steel 4b.

[0059] The change of the air gap size between the tooth portion 6a and the corresponding first magnetic steel 4a and / or second magnetic steel 4b is realized by the change of the fourth surface 401 and the fifth surface 402.

[0060] Finally, it should be noted that the above description is only a preferred embodiment of the present application, and those skilled in the art can make various similar modifications under the inspiration of the present application without departing from the purpose and scope of the present application, and such modifications fall within the protection scope of the present application.

Claims

1. A low-positioning-force rotary motor of reciprocating rotation, the rotary motor of reciprocating rotation comprising a rotor portion and a stator portion that cooperate with each other, wherein, The rotor part comprises a rotating shaft (5) and a core (6) sleeved on the rotating shaft (5), and the stator part comprises a casing (2) and a magnetic steel assembly (4) arranged on the inner wall of the casing (2), each group of the magnetic steel assembly (4) comprises a first magnetic steel (4a) and a second magnetic steel (4b) with opposite magnetic polarities, characterized in that: At least one tooth part (6a) is arranged on the core (6), and a group of the magnetic steel assembly (4) is arranged on the inner wall of the casing (2) corresponding to each tooth part (6a), and the tooth part (6a) is located between the first magnetic steel (4a) and the second magnetic steel (4b) of the corresponding magnetic steel assembly (4) in the initial position. When rotating clockwise or counterclockwise, the distance between the tooth part (6a) and the corresponding first magnetic steel (4a) and / or second magnetic steel (4b) shows a trend of first decreasing and then increasing.

2. The reciprocating rotary motor of claim 1, wherein: The rotating shaft (5) reciprocates within a preset angle clockwise and counterclockwise, and compared with the magnetic slot torque in the initial position, when the rotating shaft (5) rotates clockwise or counterclockwise by more than 50% of the preset angle, the magnetic slot torque between the tooth part (6a) and the corresponding first magnetic steel (4a) and / or first magnetic steel (4b) increases by no less than 100%.

3. A reciprocating rotary motor according to claim 1 or 2, characterised in that: The rotating shaft (5) reciprocates between 20-30° clockwise and 20-30° counterclockwise.

4. The reciprocating rotary motor of claim 3, wherein: The tooth part (6a) comprises a tooth root part (6a1) for fixing on the core (6) and a tooth top part (6a2) connected with the tooth root part (6a1), wherein the tooth root part (6a1) is wound with a coil winding (8); The top surface of the tooth top part (6a2) is provided with a separation groove (6a3), and the groove opening of the separation groove (6a3) faces the middle of the first magnetic steel (4a) and the second magnetic steel (4b) of the corresponding magnetic steel assembly (4) in the initial position.

5. The reciprocating rotary motor of claim 4, wherein: Taking the center line of the groove bottom surface of the separation groove (6a3) as a first boundary line, from the direction close to the first boundary line to the direction away from the first boundary line, the distance between the top surface of the tooth top part (6a2) and the axis of the core (6) shows a trend of first increasing and then decreasing.

6. The reciprocating rotary motor of claim 5, wherein: The top surface of the tooth top part (6a2) comprises a first surface (6a201), a second surface (6a202) and a third surface (6a203); The first surface (6a201) is connected with the second surface (6a202) and the third surface (6a203) in sequence on both sides, the second surface (6a202) is a circular arc surface concentric with the core (6), and the first surface (6a201) and the third surface (6a203) are located inside the circle where the second surface (6a202) is located.

7. The reciprocating rotary motor of claim 6, wherein: The first surface (6a201) is a concave arc surface, and the concave part forms the separation groove (6a3). The third surface (6a203) is a plane or a curved surface.

8. The reciprocating rotary motor of claim 7, wherein: The first surface (6a201) and the second surface (6a202) are connected through a smooth curved surface.

9. The reciprocating rotary motor of claim 4, wherein: The center line between the first magnetic steel (4a) and the first magnetic steel (4b) of the same group of magnetic steel assemblies (4) is a second boundary line. From the direction close to the second boundary line to the direction away from the second boundary line, the distance from the surface of the first magnetic steel (4a) and the second magnetic steel (4b) to the inner wall of the shell (2) increases.

10. The reciprocating rotary motor of claim 9, wherein: The surface of the first magnetic steel (4a) and the second magnetic steel (4b) towards the tooth portion (6a) comprises a fourth surface (401) and a fifth surface (402) spliced together, wherein the fourth surface (401) is close to the second boundary line. From the direction close to the second boundary line to the direction away from the second boundary line, the distance from the fourth surface (401) to the inner wall of the shell (2) first increases gradually, and the distance from the fifth surface (402) to the inner wall of the shell (2) remains stable.

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