Brushless direct current motor for electric toothbrush

Abstract

The utility model provides a brushless direct current motor for an electric toothbrush, and relates to the technical field of electric toothbrushes, the brushless direct current motor comprises a stator iron core, an end cover and a rotor position feedback assembly, the rotor position feedback assembly comprises an induction magnet and a hall plate, and the stator iron core is internally provided with a rotor iron core; a vibration shaft is arranged in the rotor core; the outer part of the stator core is connected with a shell in a sleeving manner; one end of the shell is connected with a mounting plate in an assembling manner; one end of the machine shell is connected with a plate support in an assembled mode, one end of the vibration shaft is connected with a magnet support in a sleeved mode, a sensing assembly is arranged in the plate support, an annular groove is machined in the inner wall of the plate support, and two magnetic Hall components are arranged on one side of the Hall plate. The technical key points are as follows: the position of a motor rotor is detected in real time through an induction magnet and a hall plate at the tail end of a vibration shaft, and FOC logic control is performed, so that the rotation angle and direction of the brushless motor are accurately controlled, and the tooth brushing action of a human body can be simulated in combination with actual working conditions.

Description

Technical Field

[0001] The utility model relates to the technical field of electric toothbrushes, in particular to a brushless DC motor used for electric toothbrushes. Background Art

[0002] Electric toothbrushes use the rapid rotation or vibration of the motor core to make the brush head vibrate at high frequency, instantly breaking down the toothpaste into fine foam, deeply cleaning the gaps between teeth, and the vibration of the bristles can promote blood circulation in the mouth and have a massage effect on the gum tissue. In principle, electric toothbrushes are divided into two types: rotary and vibrating. The principle of rotary toothbrushes is simple, that is, the motor drives the circular brush head to rotate, and the friction effect is enhanced while performing ordinary brushing actions. Rotary toothbrushes have strong power, clean the tooth surface very cleanly, and the cleaning of the gaps between teeth is relatively weak, but they cause great wear on the teeth, so long-term use is not recommended. Vibrating toothbrushes are more complicated. There is an electrically driven vibration motor inside the vibrating toothbrush, which can make the brush head produce high-frequency swings perpendicular to the direction of the brush handle, but the swing amplitude is very small.

[0003] Existing electric toothbrushes mainly rely on motors to control the vibration of transmission components, thereby controlling the swing of the toothbrush to assist brushing. However, most motors are fixed inside the handle of the electric toothbrush, and their working status cannot be monitored, making it difficult to always maintain precise position control, or during position control, it is difficult to output torque smoothly to ensure the brushing effect. Utility Model Content

[0004] In order to overcome the shortcomings of the existing electric toothbrush, in which the motor is fixedly arranged inside the electric toothbrush handle, its working state cannot be monitored, and it is difficult to always maintain precise position control, or it is difficult to output the torque smoothly during position control to ensure the brushing effect, the embodiment of the present application provides a brushless DC motor for an electric toothbrush, which detects the position of the motor rotor in real time at the tail end of the vibration shaft through an induction magnet and a hall plate, and controls the rotation angle and direction of the brushless motor accurately through FOC logic. It can simulate the brushing action of the human body in combination with actual working conditions, and solves the problems of the existing electric toothbrush motor, in which the working state cannot be monitored, and it is difficult to always maintain precise position control, or it is difficult to output the torque smoothly during position control.

[0005] The technical solution adopted by the embodiment of the present application to solve the technical problem is:

[0006] A brushless DC motor for an electric toothbrush comprises a stator core, an end cover and a rotor position feedback assembly, wherein the end cover is arranged on one side of the stator core;

[0007] The rotor position feedback component is arranged on one side of the end cover;

[0008] Among them, the rotor position feedback component includes an induction magnet and a hall plate, a rotor core is arranged inside the stator core, four motor magnets are arranged between the inner side of the stator core and the outer side of the rotor core, a vibration shaft is arranged inside the rotor core, the outer sides of both ends of the vibration shaft are sleeve-connected with bearings, the outer side of the stator core is sleeve-connected with a casing, one end of the casing is assembled with a mounting plate, and the end cover is assembled with the other end of the casing.

[0009] In a possible implementation, one end of the housing is assembled with a plate support, the plate support is snap-connected to one side of the end cover, one end of the vibration shaft extends from the inside of the end cover, and the induction magnet is sleeve-connected to the outside of this end of the vibration shaft.

[0010] In a possible implementation, a magnet support is sleeve-connected to the outside of one end of the vibration shaft, and the magnet support is located between the end cover and the induction magnet.

[0011] In a possible implementation, the induction magnet is in a ring shape, and its two poles are sinusoidally magnetized.

[0012] In one possible implementation, a sensor component is disposed inside the plate support, an annular groove is processed on the inner wall of the plate support, two magnetic Hall components are disposed on one side of the hall plate, the two magnetic Hall components are placed at a 90° angle and connected to a sensor component, and the sensor component is fixed to the plate support via the annular groove.

[0013] In one possible implementation, the bottom inner wall of the plate support is processed with two bases that are symmetrical about the origin, the bottom of the plate support is processed with a wire outlet groove and a mounting hole, the top of the base is processed with a positioning column, and the hall plate is snap-connected to the inside of the plate support and fixedly connected to the base by bolts.

[0014] In a possible implementation, the rotor position feedback component uses FOC and an encoder to implement motor rotation position control, and implements vibration control by superimposing reverse current modulation.

[0015] In summary, the present invention includes at least one of the following beneficial technical effects:

[0016] Through the induction magnet and the hall plate at the tail end of the vibration shaft, the motor rotor position is detected in real time, and through FOC logic control, the angle and direction of rotation of the brushless motor can be accurately controlled. It can be combined with actual working conditions to simulate the human brushing action, solving the problems that the working status of the existing electric toothbrush motor cannot be monitored, it is difficult to always maintain precise position control, or it is difficult to output the torque smoothly during position control. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0018] Figure 2 It is an exploded view of the utility model;

[0019] Figure 3 For this utility model Figure 2 The enlarged schematic diagram of the middle A part;

[0020] Figure 4 This is a schematic diagram of the structure of the positioning column of the utility model;

[0021] Figure 5 It is a cross-sectional view of the plate support of the utility model;

[0022] Figure 6 This is the principle diagram of the motor rotation position control of the utility model.

[0023] Description of the drawings: 1. Vibration shaft; 2. Casing; 3. Plate support; 4. Hall plate; 5. Mounting plate; 6. Stator core; 7. Bearing; 8. Motor magnet; 9. Rotor core; 10. Base; 11. Positioning column; 12. Induction magnet; 13. End cover; 14. Magnet support. DETAILED DESCRIPTION

[0024] The technical solution in the embodiment of the present application is to solve the problems of the above-mentioned background technology, and the overall idea is as follows:

[0025] Embodiment 1:

[0026] This embodiment introduces a specific structure of a brushless DC motor for an electric toothbrush. Figure 1-Figure 6 As shown, it includes a stator core 6, an end cover 13 arranged on one side of the stator core 6, and a rotor position feedback component arranged on one side of the end cover 13, the rotor position feedback component includes an induction magnet 12 and a hall plate 4, a rotor core 9 is arranged inside the stator core 6, four motor magnets 8 are arranged between the inner side of the stator core 6 and the outer side of the rotor core 9, a vibration shaft 1 is arranged inside the rotor core 9, the outer sides of both ends of the vibration shaft 1 are sleeve-connected with bearings 7, and the outer side of the stator core 6 is sleeve-connected with a housing 2;

[0027] Among them, by assembling the mounting plate 5 at one end of the housing 2 and assembling the end cover 13 to the other end of the housing 2, the motor assembly of the electric toothbrush can be encapsulated inside the housing 2, so that the electric toothbrush basically maintains the existing structural state;

[0028] At the same time, in order to fix the end cover 13 and the rotor position feedback assembly to the tail of the electric toothbrush, the rotor position feedback assembly monitors and controls the working state of the brushless motor inside the electric toothbrush, such as Figure 1 and Figure 5 As shown, one end of the housing 2 is assembled with a plate support 3, and the plate support 3 is snap-connected to one side of the end cover 13. By extending one end of the vibration shaft 1 from the inside of the end cover 13, the induction magnet 12 can be sleeve-connected to the outside of the end of the vibration shaft 1, so that the hall plate 4 is fixed to the tail end of the vibration shaft 1;

[0029] Secondly, the outer sleeve connection of one end of the vibration shaft 1 is provided with a magnet support 14, which is located between the end cover 13 and the induction magnet 12, and the induction magnet 12 is annular, and its two poles are sinusoidally magnetized, and the induction magnet 12 is not connected to the structural parts of the electric toothbrush, but is only sleeved on the tail of the vibration shaft 1, which can ensure the magnetic strength of the induction magnet 12 and the control accuracy;

[0030] Furthermore, a sensor component is disposed inside the plate support 3 so that the sensor component can cooperate with the induction magnet 12 to monitor the working state of the electric toothbrush housing 2. Figure 4 As shown, the inner wall of the plate support 3 is processed with an annular groove, and the sensor component is fixed to the plate support 3 through the annular groove;

[0031] At the same time, two magnetic Hall components are arranged on one side of the hall plate 4, and the two magnetic Hall components are placed at a 90° angle and connected to a sensor component, so as to transmit the working status information of the brushless motor on the electric toothbrush;

[0032] Further, such as Figure 6 As shown, the rotor position feedback component uses FOC and encoder to achieve motor rotation position control, and realizes vibration control by superimposing reverse current modulation;

[0033] In some examples, in order to facilitate the fixing of the hall board 4 and the board support 3 and ensure the stable connection of the electrical components, such as Figure 4 As shown, the bottom inner wall of the plate support 3 is processed with two bases 10 which are symmetrical about the origin, the bottom of the plate support 3 is processed with a wire outlet groove and a mounting hole, and the top of the base 10 is processed with a positioning column 11. The hall plate 4 can be connected and fixed to the plate support 3 by snapping the hall plate 4 into the interior of the plate support 3, and threading the base 10 with bolts passing through the interior of both sides of the hall plate 4, and inserting the positioning columns 11 on the base 10 into the interior of the hall plate 4.

[0034] Specifically, when the brushless DC motor is used to support the electric toothbrush:

[0035] With the help of the induction magnet 12 and the hall plate 4 arranged at the tail of one end of the vibration shaft 1, when the vibration shaft 1 is controlled by the brushless motor inside the casing 2, the motor rotor position is detected in real time through the induction magnet 12 and the hall plate 4 at the tail end of the vibration shaft 1, and through FOC logic control, the angle and direction of rotation of the brushless motor are accurately controlled. Combined with the actual working conditions, the human body brushing action is simulated, and the motor is controlled by the above principle to rotate forward and reverse at a set angle. In high-speed forward and reverse rotation, the motor can also generate a high-frequency vibration effect, thereby simulating the human body brushing action.

[0036] Finally, it should be noted that: Obviously, the above embodiments are only examples for clearly explaining the present invention, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from this are still within the scope of protection of the present invention.

Claims

1. A brushless DC motor for an electric toothbrush, characterized in that: include: Stator core (6); An end cover (13) is arranged on one side of the stator core (6); A rotor position feedback component, which is arranged on one side of the end cover (13); The rotor position feedback component comprises an induction magnet (12) and a hall plate (4); a rotor core (9) is arranged inside the stator core (6); four motor magnets (8) are arranged between the inner side of the stator core (6) and the outer side of the rotor core (9); a vibration shaft (1) is arranged inside the rotor core (9); the outer sides of both ends of the vibration shaft (1) are sleeve-connected with bearings (7); the outer side of the stator core (6) is sleeve-connected with a housing (2); one end of the housing (2) is assembled with a mounting plate (5); and the end cover (13) is assembled with the other end of the housing (2).

2. A brushless DC motor for an electric toothbrush as claimed in claim 1, characterized in that: One end of the housing (2) is assembled with a plate support (3), and the plate support (3) is snap-connected to one side of the end cover (13). One end of the vibration shaft (1) extends from the inside of the end cover (13), so that the induction magnet (12) is sleeve-connected to the outside of the end of the vibration shaft (1).

3. A brushless DC motor for an electric toothbrush as claimed in claim 1, characterized in that: A magnet support (14) is sleeve-connected to the outside of one end of the vibration shaft (1), and the magnet support (14) is located between the end cover (13) and the induction magnet (12).

4. A brushless DC motor for an electric toothbrush as claimed in claim 1, characterized in that: The induction magnet (12) is annular and has two poles that are sinusoidally magnetized.

5. A brushless DC motor for an electric toothbrush as claimed in claim 2, characterized in that: A sensor component is arranged inside the plate support (3), and an annular groove is processed on the inner wall of the plate support (3). Two magnetic Hall components are arranged on one side of the hall plate (4), and the two magnetic Hall components are placed at an angle of 90° and connected to a sensor component. The sensor component is fixed to the plate support (3) via the annular groove.

6. A brushless DC motor for an electric toothbrush as claimed in claim 2, characterized in that: The bottom inner wall of the plate support (3) is processed with two bases (10) symmetrical about the origin, the bottom of the plate support (3) is processed with a wire outlet groove and a mounting hole, the top of the base (10) is processed with a positioning column (11), and the hall plate (4) is snap-connected to the inside of the plate support (3) and fixedly connected to the base (10) by bolts.

7. A brushless DC motor for an electric toothbrush as claimed in claim 1, characterized in that: The rotor position feedback component uses FOC and an encoder to achieve motor rotation position control, and achieves vibration control by superimposing reverse current modulation.

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