Motor structure for low-cost and high-efficiency outer rotor electric toothbrush

Abstract

A motor structure for a low-cost high-efficiency outer rotor electric toothbrush is characterized by comprising a motor, a circuit board, a bearing, a spring, a copper sleeve and a magnetic ring, the motor is composed of a rotor assembly, a stator assembly, a stator support, a magnet and a machine shell, the stator assembly is assembled on the inner side of the rotor assembly, and the circuit board is connected with the motor through a power line. Two or three Hall sensors are arranged on a circuit board, position signals of rotation of a motor are set, so that a rotation position phase angle of a rotor assembly is limited, the motor is driven and controlled to reciprocate repeatedly within a certain angle, and a rotor of the motor of the electric toothbrush is designed to be in an external rotation and internal stator mode. The outer diameter of the rotor assembly is designed to be 14-15.2 mm, the inner diameter of the rotor assembly is designed to be 13-14.5 mm, the magnet is 10-30 mm, the lamination length of the motor stator assembly is 15-25 mm, the outer diameter of a stator core is 9-11.5 mm, one end of the rotor assembly is supported by a bearing on a stator support, the other end of the rotor assembly is fixedly supported by a bearing of a machine shell, and due to the design of the bearings at the two ends, the running stability and the working efficiency of the motor are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of electric toothbrush motors, in particular to a motor structure for a low-cost and high-efficiency external-rotor electric toothbrush. Background Art

[0002] The working principles of electric toothbrush motors are mainly divided into two types: mechanical rotation type and sonic vibration type. The working principle of a mechanically rotating electric toothbrush is that the motor drives a circular brush head to rotate. This rotation method is similar to manual brushing, but it enhances the friction effect and can more effectively remove dental calculus, dental plaque, and food residues. Mechanically rotating electric toothbrushes have strong cleaning power and obvious cleaning effects can be seen in a short time, but they also cause relatively greater wear on teeth. Sonic vibration type electric toothbrushes generate high-frequency vibrations through the motor, which drives the bristles on the brush head to swing at high frequencies. This vibration method can mix water flow and toothpaste into fine foam, and use the impact force generated by high-frequency vibration to deeply clean teeth in the interdental spaces, thereby achieving the effect of cleaning teeth. Sonic vibration type electric toothbrushes have strong stability, large output power, and because the friction of the magnetic levitation motor is very small, even when operating at high speeds, the noise is within an acceptable range.

[0003] In summary, the working principles of electric toothbrush motors vary according to their types. The mechanically rotating type cleans by rotating the brush head, while the sonic vibration type achieves the cleaning effect through high-frequency vibration. Existing electric toothbrush motors generally have an internal-rotor structure (i.e., the rotating rotors are all inside). Motors with an internal-rotor structure have problems of high cost and low working efficiency. Therefore, it is necessary to design a motor structure for a low-cost and high-efficiency external-rotor electric toothbrush to solve the above technical problems. Summary of the Utility Model

[0004] The purpose of the utility model is to solve the technical problem that existing electric toothbrush motors generally have an internal-rotor structure (i.e., the rotating rotors are all inside), and motors with an internal-rotor structure have problems of high cost and low working efficiency. A motor structure for a low-cost and high-efficiency external-rotor electric toothbrush is provided to solve the above technical problems. By adopting a brand-new external-rotor structure, that is, changing the rotor to rotate externally and the stator internally, the rotor assembly is designed to have an outer diameter of 14 mm - 15.2 mm and an inner diameter of 13 mm - 14.5 mm. Since the motor power P is proportional to the volume, the stack length dimension of the stator assembly of the motor is shortened from the original 35 mm to 15 mm - 25 mm. Since Pin = Pout + P (iron loss) + P (eddy current) + P (copper loss) + P (mechanical), after the motor length is reduced, P (iron loss) + P (eddy current) + P (copper loss) will all decrease, and the efficiency of the motor is greatly improved, and the cost of the motor is greatly reduced.

[0005] A motor structure for a low-cost and high-efficiency external-rotor electric toothbrush, characterized in that it includes a motor, a circuit board, bearings, springs, copper sleeves and magnetic rings. There are two bearings. The motor is composed of a rotor assembly, a stator assembly, a stator bracket, magnets and a housing. The rotor assembly is composed of a shaft core, a copper sleeve and a rotor housing. The stator assembly is composed of enameled wires and a stator core. The enameled wires are assembled in the slots of the stator core. The copper sleeve is assembled on the shaft core, and the rotor housing is assembled on the outside of the copper sleeve. The stator assembly is assembled on the inside of the rotor assembly. The magnets are assembled inside the rotor housing. The tail end of the shaft core is rotatably installed on the stator bracket through a bearing, and the front end is rotatably installed on the housing through a bearing. The circuit board is connected to the motor through a power cord. There are two or three Hall sensors on the circuit board. The Hall sensors are switch Hall or linear Hall. The magnetic ring is fixed to the tail end of the shaft core through a rear copper sleeve. The magnetic ring is a pair-pole magnetic ring. The spring is assembled at the front end of the shaft core and connected to the rotor assembly.

[0006] Further, the outer diameter of the rotor assembly is 14 mm - 15.2 mm, and the inner diameter is 13 mm - 14.5 mm.

[0007] Further, the enameled wires are connected to the circuit board.

[0008] Further, the stator core is provided with 9 slots or 6 slots. The outer diameter of the stator core is 9 mm - 11.5 mm. The stator core is stacked by a number of silicon steel chips with a thickness of 0.2 mm - 0.5 mm, and the stacking height is 15 - 25 mm.

[0009] Further, the enameled wires are made of pure copper enameled wires.

[0010] Further, the stator core is fixed on the stator bracket by interference fit or transition fit.

[0011] Further, the circuit board is fixed on the stator bracket by riveting.

[0012] Further, the rotor assembly adopts a 4-6-8-10-12-14 pole design.

[0013] Further, the length of the magnetic ring is 10 mm - 30 mm, and the structure of the magnetic ring is circular, tile-shaped or other irregular shapes.

[0014] Compared with the prior art, the advantages of the present utility model include: the electric toothbrush motor is designed into a brand-new outer rotor structure, that is, the rotor design of the electric toothbrush motor is changed to an external rotation and internal stator method. One end of the rotor assembly is rotatably installed on the casing through a bearing, and the other end is rotatably installed on the stator bracket through a bearing, realizing the stable operation of the rotor assembly. With the design of the two bearings, when the motor drives the shaft core to move, the energy loss is almost zero, greatly improving the overall performance and working efficiency of the motor.

[0015] During the operation of the electric toothbrush motor provided by the present utility model, two or three Hall sensors set on the circuit board are used to set the position signal of the motor rotation, thereby limiting the rotation position phase angle of the rotor assembly, and then driving and controlling the motor to repeat reciprocating motion within a certain angle. The motor torque T is directly proportional to the rotor diameter D. For the outer rotor motor designed by the present utility model, under the condition of ensuring the normal operation of the electric toothbrush motor, the rotor assembly is designed with an outer diameter of 14 mm - 15.2 mm and an inner diameter of 13 mm - 14.5 mm. Since the motor power P is directly proportional to the volume, the stack length dimension of the stator assembly of the motor is shortened from the original 35 mm to 15 mm - 25 mm. Since Pin = Pout + P (iron loss) + P (eddy current) + P (copper loss) + P (mechanical), after the motor length is reduced, P (iron loss) + P (eddy current) + P (copper loss) will all decrease, greatly improving the efficiency of the motor and greatly reducing the cost of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the drawings required for the description of the embodiments.

[0017] Figure 1 is an exploded view of the structure of a low-cost and high-efficiency outer rotor electric toothbrush motor provided in the embodiment of the present utility model;

[0018] Figure 2 is a three-dimensional view of the structure of a low-cost and high-efficiency outer rotor electric toothbrush motor provided in the embodiment of the present utility model;

[0019] Figure 3 is a three-dimensional view of the stator assembly in the structure of a low-cost and high-efficiency outer rotor electric toothbrush motor provided in the embodiment of the present utility model;

[0020] Figure 4 is a three-dimensional view of the stator core in the structure of a low-cost and high-efficiency outer rotor electric toothbrush motor provided in the embodiment of the present utility model;

[0021] Figure 5 is a three-dimensional view of the enameled wire in the structure of a low-cost and high-efficiency outer rotor electric toothbrush motor provided in the embodiment of the present utility model;

[0022] Figure 6 It is a three-dimensional view of the stator bracket in the motor structure of a low-cost and high-efficiency external-rotor electric toothbrush provided in the embodiment of the present utility model;

[0023] Figure 7 It is a three-dimensional view of the rotor assembly in the motor structure of a low-cost and high-efficiency external-rotor electric toothbrush provided in the embodiment of the present utility model;

[0024] Figure 8 It is a right view of the rotor assembly in the motor structure of a low-cost and high-efficiency external-rotor electric toothbrush provided in the embodiment of the present utility model;

[0025] Figure 9 It is a schematic diagram of the structure of the circuit board mounting the Hall sensor in the motor structure of a low-cost and high-efficiency external-rotor electric toothbrush provided in the embodiment of the present utility model;

[0026] In the drawings: 1. Motor; 2. Circuit board; 3. Rotor assembly; 4. Stator assembly; 5. Stator bracket; 6. Magnet; 7. Bearing; 8. Housing; 9. Spring; 10. Rear copper sleeve; 11. Magnetic ring; 301. Shaft core; 302. Copper sleeve; 303. Rotor housing; 401. Enameled wire; 402. Stator iron core; 201. Hall sensor. Detailed implementation manners

[0027] In view of the deficiencies in the prior art, through long-term research and a large number of practices in this case, the technical solution of the present utility model can be proposed. The technical solution in the embodiment of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings in the embodiment of the present utility model.

[0028] Please refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 , Figure 1 It is an exploded view of the structure of the motor structure of a low-cost and high-efficiency external-rotor electric toothbrush provided in the embodiment of the present utility model, Figure 2 It is a three-dimensional view of the structure of the motor structure of a low-cost and high-efficiency external-rotor electric toothbrush provided in the embodiment of the present utility model, Figure 3 It is a three-dimensional view of the stator assembly in the motor structure of a low-cost and high-efficiency external-rotor electric toothbrush provided in the embodiment of the present utility model, Figure 4 It is a three-dimensional view of the stator iron core in the motor structure of a low-cost and high-efficiency external-rotor electric toothbrush provided in the embodiment of the present utility model, Figure 5It is a three-dimensional structure diagram of the enameled wire in a motor structure for a low-cost and high-efficiency external-rotor electric toothbrush provided in an embodiment of the present utility model. Figure 6 It is a three-dimensional structure diagram of the stator bracket in a motor structure for a low-cost and high-efficiency external-rotor electric toothbrush provided in an embodiment of the present utility model. Figure 7 It is a three-dimensional structure diagram of the rotor assembly in a motor structure for a low-cost and high-efficiency external-rotor electric toothbrush provided in an embodiment of the present utility model. Figure 8 It is a schematic structural diagram of the circuit board mounting a Hall sensor in a motor structure for a low-cost and high-efficiency external-rotor electric toothbrush provided in an embodiment of the present utility model. Figure 9 It is a schematic structural diagram of the circuit board mounting a switch in a motor structure for a low-cost and high-efficiency external-rotor electric toothbrush provided in an embodiment of the present utility model, as Figures 1 to 9As shown in the figure, a motor structure for a low-cost and high-efficiency external-rotor electric toothbrush is characterized by including a motor 1, a circuit board 2, bearings 7, a spring 9, a rear copper sleeve 10, and a magnetic ring 11. The motor 2 is composed of a rotor assembly 3, a stator assembly 4, a stator bracket 5, a magnet 6, and a housing 8. There are two bearings 7. The rotor assembly 3 is composed of a shaft core 301, a copper sleeve 302, and a rotor housing 303. The stator assembly 4 is composed of an enameled wire 401 and a stator core 402. The enameled wire 401 is assembled in the slots of the stator core 402. The copper sleeve 302 is assembled on the shaft core 301, and the rotor housing 303 is assembled on the outside of the copper sleeve 302. The stator assembly 4 is assembled inside the rotor assembly 3. When the motor works, the rotor assembly 3 rotates at a high speed outside, and the stator assembly 4 does not rotate. The magnet 6 is assembled inside the rotor housing 303. The tail end of the shaft core 301 is rotatably installed on the stator bracket 5 through the bearing 7, and the front end is rotatably installed on the housing 8 through the bearing 7. This design enables one end of the rotor assembly to be rotatably installed on the housing through the bearing, and the other end to be rotatably installed on the stator bracket through the bearing, realizing the smooth operation of the rotor assembly. With the design of the two bearings 7, when the motor 1 drives the shaft core 301 to move, the energy loss is almost zero, greatly improving the working efficiency of the motor. The circuit board 2 is connected to the motor 1 through a power cord. The enameled wire 401 is connected to the circuit board 2. There are two or three Hall sensors 201 on the circuit board 2. The Hall sensors 201 are switch Hall or linear Hall. During the operation of the motor 1, the rotation position signal of the motor 1 is set through the set Hall sensors 201, thereby limiting the rotation position phase angle of the rotor assembly 3. Then, the motor is driven to repeat reciprocating motion within a certain angle. The outer diameter of the rotor assembly 3 is 14 mm - 15.2 mm, and the inner diameter of the structure of the rotor assembly 3 is 13 mm - 14.5 mm. Since the motor power P is proportional to the volume, the stack length dimension of the stator assembly of the motor is shortened from the original 35 mm to 15 mm - 25 mm. Since Pin = Pout + P (iron loss) + P (eddy current) + P (copper loss) + P (mechanical), after the motor length is reduced, P (iron loss) + P (eddy current) + P (copper loss) will all decrease, greatly improving the efficiency of the motor 1 and greatly reducing the cost of the motor. The magnetic ring 11 is fixed to the tail end of the shaft core 301 through the rear copper sleeve 10. The magnetic ring 11 is a pair-pole magnetic ring. The design of the pair-pole magnetic ring can ensure that the normal and useful signals can pass through unobstructed when the motor works, and can also well suppress the passage of high-frequency interference signals, ensuring the normal operation of the motor and having a low cost, further reducing the manufacturing cost of the motor. The spring 9 is assembled at the front end of the shaft core 301 and is connected to the rotor assembly 3. The spring 9 is used to prevent the rotor assembly 3 from moving axially and provides a pre-tightening force for the bearing.

[0029] Preferably, the stator core 402 is provided with 9 slots or 6 slots, the outer diameter of the stator core 402 is between 9 mm and 11.5 mm, the stator core 402 is stacked by a plurality of silicon steel sheets with a thickness of 0.2 mm - 0.5 mm, and the enameled wire 401 is an enameled wire made of pure copper. The selection of materials with excellent properties such as silicon steel core and pure copper ensures the working efficiency and service performance of the motor.

[0030] Preferably, the motor 1 is designed as an outer rotor structure, that is, the rotor rotates at a high speed outside, with high heat dissipation efficiency, low power consumption, stable voltage, and long service life of the electric toothbrush motor.

[0031] Preferably, the stator core 402 is fixed on the stator bracket 5 by interference fit or transition fit, and the circuit board 2 is fixed on the stator bracket 5 by riveting. The motor components are assembled by means of riveting, interference fit and transition fit, and the motor assembly is simple and efficient.

[0032] Preferably, the rotor assembly adopts a 4 - 6 - 8 - 10 - 12 - 14 pole design, the length of the magnetic ring is between 10 mm and 30 mm, the structure of the magnetic ring is circular, square or other irregular shapes, and the structure shape of the magnetic ring is not limited as long as it can be assembled in the motor. In actual use, the magnetic ring can also be replaced by magnetic sheets.

[0033] A motor structure for a low - cost and high - efficiency outer rotor electric toothbrush provided by the present utility model. It should be understood that the above - mentioned embodiments are only used to illustrate the technical concept and characteristics of the present utility model. The purpose is to enable those skilled in the art to understand the content of the present utility model and implement it accordingly, and it cannot be used to limit the protection scope of the present utility model. Any simple modifications and substitutions made using the content of the present utility model are included in the protection scope of the present utility model.

Claims

1. A motor structure for a low-cost and highly efficient external rotor electric toothbrush, characterized in that: It includes a motor, a circuit board, bearings, springs, a rear copper sleeve and a magnetic ring. There are two bearings. The motor consists of a rotor assembly, a stator assembly, a stator bracket, magnets and a housing. The rotor assembly consists of a shaft core, a copper sleeve and a rotor housing. The stator assembly consists of enameled wire and a stator core. The enameled wire is assembled in the slots of the stator core. The copper sleeve is assembled on the shaft core, and the rotor housing is assembled on the outside of the copper sleeve. The stator assembly is assembled on the inside of the rotor assembly. The magnets are assembled inside the rotor housing. The tail end of the shaft core is rotatably installed on the stator bracket through a bearing, and the front end is rotatably installed on the housing through a bearing. The circuit board is connected to the motor through a power cord. There are two or three Hall sensors on the circuit board. The Hall sensors are switch Hall or linear Hall. The magnetic ring is fixed to the tail end of the shaft core through the rear copper sleeve. The magnetic ring is a pair-pole magnetic ring. The spring is assembled at the front end of the shaft core and connected to the rotor assembly.

2. The motor structure for a low-cost and high-efficiency external-rotor electric toothbrush according to claim 1, wherein: The outer diameter of the rotor assembly is 14mm - 15.2mm, and the inner diameter is 13mm - 14.5mm.

3. The motor structure for a low-cost and highly efficient external-rotor electric toothbrush according to claim 1, wherein: The length of the magnets is 10mm - 30mm.

4. A motor structure for a low-cost and high-efficiency external-rotor electric toothbrush according to claim 1, characterized in that: The enameled wire is connected to the circuit board.

5. The motor structure for a low-cost and highly efficient external rotor electric toothbrush according to claim 1, wherein: The stator core has 9 slots or 6 slots. The outer diameter of the stator core is 9mm - 11.5mm. The stator core is stacked by a number of silicon steel chips with a thickness of 0.2mm - 0.5mm.

6. The motor structure for a low-cost and high-efficiency external rotor electric toothbrush according to claim 1, wherein: The enameled wire is made of pure copper.

7. The motor structure for a low-cost and highly efficient external rotor electric toothbrush according to claim 1, wherein: The stator core is fixed on the stator bracket by interference fit or press fit.

8. The motor structure for a low-cost and highly efficient external rotor electric toothbrush according to claim 1, characterized in that: The circuit board is fixed on the stator bracket by riveting.

9. The motor structure for a low-cost and highly efficient external-rotor electric toothbrush according to claim 1, characterized in that: The rotor assembly adopts a 4-6-8-10-12-14 pole design.

10. The motor structure for a low-cost and high-efficiency external-rotor electric toothbrush according to claim 1, characterized in that: The length of the magnetic ring is 10mm - 30mm, and the structure of the magnetic ring is circular or tile-shaped.

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