High-frequency power multi-mode electric toothbrush

Abstract

A high-frequency power multi-mode electric toothbrush, comprising a body housing (10), a swing motor (20), a battery (30), a rotary brush rod, and a swing brush rod. The body housing (10) is hollow to form an inner accommodating space. The rear end of the inner accommodating space of the body housing (10) is closed by means of a detachable tail cover (11). The body housing (10) accommodates a control circuit board (13), and a plurality of function buttons (12) connected to the control circuit board (13) are arranged on the side wall. The battery (30) is arranged at the rear end of the inner accommodating space. The battery (30) is electrically connected to the control circuit board (13) and the swing motor (20). The swing motor (20) is arranged at the front end of the inner accommodating space of the body housing (10). An output shaft (245) of the swing motor (20) extends from the front end of the body housing (10) and is connected to the rotary brush rod or the swing brush rod located at the front end of the body housing (10) to output power. The swing motor (20) comprises a motor support (21), an electromagnetic coil (22), a vibration arm assembly (24), a front cover (25), and a magnet (27). Thus, the toothbrush effectively combines two modes of a high-frequency rotary brush rod and a high-frequency swing brush rod, and the rotational or swing frequency is effectively improved. Flexible compensation is used to solve the problems of noise and service life in brush rods operating at a high frequency.

Description

High-frequency power multi-mode electric toothbrush Technical Field

[0001] This invention relates to the technical field of electric toothbrushes, and more particularly to a high-frequency power multi-mode electric toothbrush that can be adapted to both a high-frequency rotating brush handle and a high-frequency vibrating brush handle. Background Technology

[0002] Currently, high-frequency power output toothbrushes can be divided into two types based on the movement of the brush head: one type has an integrated brush handle and brush head, with the entire brush handle vibrating; the other type has a circular or elliptical brush head that reciprocates. Generally, the reciprocating brush head design faces far more technical challenges than the brush handle vibration design. The main common problems include:

[0003] 1. The brush head rotates, and the brush handle is often designed with a combination of multiple moving parts. Common designs include: a rotating shaft, and a mechanism that actuates or links the brush disc. Due to manufacturing tolerances, it is difficult to avoid noise in the movement of these mechanisms.

[0004] 2. Because the brush head works for a long time under the conditions of cleaning and abrasive materials such as toothpaste, the wear of moving parts will be accelerated, which will further increase the noise. Due to the wear of the workpiece, the actual movement stroke between the components will be reduced, which will eventually manifest as the brush plate output swing angle deteriorating and weakening, failing to meet the cleaning requirements.

[0005] 3. Conventional economical DC motor-driven electric toothbrushes have a maximum operating speed of less than 133Hz and require gear sets or lever linkages to complete torque conversion; otherwise, the direct-drive output torque is too small to meet the cleaning power requirements. For example, to ensure the brush head can operate effectively at 140-350Hz, the DC motor speed must be 2-4 times higher than the brush plate output speed for the gear set torque conversion. Under these conditions, conventional power conversion mechanisms generate excessive noise that is uncomfortable for the user, and component wear increases dramatically with the increased speed, affecting product lifespan. This invention proposes a high-frequency oscillating motor with direct drive and no torque conversion mechanism.

[0006] 4. Common electric toothbrushes can only be used with one type of brush head for cleaning: a reciprocating rotating brush head or a high-frequency oscillating brush head. You can only choose one of the two.

[0007] Therefore, in view of the above-mentioned defects, the designers of this invention, through dedicated research and design, and by integrating years of experience and achievements in related industries, have researched and designed a high-frequency power multi-mode electric toothbrush to overcome the above-mentioned defects. Summary of the Invention

[0008] The purpose of this invention is to provide a high-frequency power multi-mode electric toothbrush that overcomes the shortcomings of the prior art. It is driven by oscillating vibration, which overcomes the shortcomings of the push-pull torque in the prior art. It effectively combines the two modes of high-frequency rotary brush bar and high-frequency oscillating brush bar, and the rotation or oscillation frequency is effectively improved. Flexible compensation is used to solve the problems of brush bar noise and lifespan under high-frequency operation.

[0009] To achieve the above objectives, this invention discloses a high-frequency power multi-mode electric toothbrush, comprising a main body shell, a oscillating motor, a rotating brush bar, and an oscillating brush bar. The main body shell is hollow to form an internal space, and a control circuit board is housed within the main body shell, with multiple function buttons connected to the control circuit board located on the side wall. Its distinguishing feature is that:

[0010] The built-in space of the main body housing is equipped with a oscillating motor. The output shaft of the oscillating motor extends from the front end of the main body housing to provide power output. The oscillating motor includes a motor bracket, an electromagnetic coil, a vibrating arm assembly, a front cover, and a magnet. The front end of the motor bracket is equipped with a front cover, and the rear end is equipped with a magnet. A shock-absorbing block is also provided on the rear side of the magnet. An inner cavity is formed inside the motor bracket to accommodate the vibrating arm assembly. The rear outer edge of the inner cavity is covered with an electromagnetic coil.

[0011] The vibrating arm assembly includes a swing arm, a rotating shaft, bearings, and a connecting frame. The rear part of the swing arm is located in an electromagnetic coil at the rear of the inner cavity. The front part of the swing arm forms a disc portion with a shaft hole for the rotating shaft to pass through. The two ends of the rotating shaft are rotatably supported by a motor bracket via bearings. The rear end of the connecting frame covers the front part of the swing arm and forms a cylindrical structure that accommodates the disc portion of the swing arm. The front end of the connecting frame is connected to the rear end of the output shaft to transmit the vibration generated by the vibrating arm assembly to the output shaft for output.

[0012] The swing arm, rotating shaft, and output shaft are integrated into a vibration arm assembly by forming a connecting frame through secondary plastic injection molding. The swing arm is a straight iron swing arm, and the rotation axis of the rotating shaft is perpendicular to the swing direction of the swing arm.

[0013] Wherein: both ends of the rotating shaft are provided with shaft shoulders that cooperate with the bearings, and the rear end of the output shaft is provided with at least one concave ring, so that the output shaft and the connecting frame are stably integrally formed after secondary injection molding.

[0014] The swing arm is made of stacked silicon steel sheets with high frequency and low eddy current loss.

[0015] The rotating brush rod includes a brush rod housing, an inner support, a rotating brush head assembly, and a power transmission assembly. The inner support is disposed inside the brush rod housing to form an internal space for the built-in power transmission assembly. The rotating brush head assembly is disposed at the front end of the brush rod housing. The rear end of the rotating power transmission assembly is connected to the output shaft of the oscillating motor, and the front end is connected to the rotating brush head assembly, thereby transmitting the output power of the oscillating motor to the rotating brush head assembly.

[0016] The rotating brush head assembly includes a brush head base and rotating bristles. The brush head base is rotatably disposed inside the front end of the brush handle housing. One end of the brush head base is fitted with multiple rotating bristles for cleaning, and the other end is provided with a base connected to the rotating power transmission assembly.

[0017] The rotary power transmission assembly includes a rocker arm, an elastic fulcrum, an elastic coupler, a drive head, a compensating spring, and a connecting sleeve. The front end of the rocker arm is provided with a drive head that extends into the base of the brush head holder. The base of the brush head holder forms a passive component that matches the shape of the drive head. A compensating spring is sleeved between the drive head and the elastic fulcrum on the rocker arm. The rear end of the rocker arm extends into the front end of the connecting sleeve. The rear end of the connecting sleeve is connected to the output shaft through the elastic coupler.

[0018] The oscillating brush rod includes a brush rod housing, an internal support, an oscillating brush head assembly, and an oscillating power transmission assembly. The internal support is disposed within the brush rod housing to form an internal space for the built-in oscillating power transmission assembly. The oscillating brush head assembly is disposed at the front end of the brush rod housing. The rear end of the oscillating power transmission assembly is connected to the output shaft of the oscillating motor, and the front end is connected to the oscillating brush head assembly, thereby transmitting the output power of the oscillating motor to the oscillating brush head assembly.

[0019] The oscillating brush head assembly includes a brush head, a rotating shaft, a bristle tuft seat, and oscillating brush bristles. The rear end of the brush head extends into the front end of the brush head housing and is rotatably fixed to the internal support via the rotating shaft. The front end of the brush head is fixed with a bristle tuft seat, and the bristle tuft seat is fitted with multiple oscillating brush bristles for cleaning.

[0020] The pendulum vibration transmission component includes a pendulum shaft, a coupling block, and a connecting tube. The front end of the pendulum shaft is embedded in the recessed hole at the rear end of the brush head, and the rear end extends into the front end of the connecting tube. The rear end of the connecting tube is connected to the output shaft through the coupling block.

[0021] As can be seen from the above, the high-frequency power multi-mode electric toothbrush of the present invention has the following effects:

[0022] 1. This high-frequency rotary toothbrush technology, capable of operating effectively at 140-350Hz, utilizes a high-torque output oscillating motor instead of a traditional DC motor, reducing noise caused by gear sets or linkages that alter torque transfer. The replaceable toothbrush handle achieves power coupling via a coupling on the handle, transmitting the oscillating torque of the toothbrush body through the handle's pivot shaft using leverage to drive the handle's rotation. A non-rotating, oscillating handle can also be fitted, achieving high-frequency reciprocating oscillation driven by the oscillating motor to meet diverse user requirements.

[0023] 2. The oscillating motor drives the brush rod through a linkage and lever mechanism, and a clearance compensation mechanism is set at the linkage joint and lever fulcrum, which effectively solves the problems of high noise and easy wear in actual use.

[0024] 3. It combines the functions of both high-frequency rotary brush rod and high-frequency oscillating brush rod.

[0025] The details of this invention will become apparent from the following description and the accompanying drawings. Attached Figure Description

[0026] Figure 1 shows a schematic diagram of an embodiment of the high-frequency power multi-mode electric toothbrush of the present invention, in which the rotating brush bar cooperates with the oscillating motor.

[0027] Figure 2 shows a schematic diagram of an embodiment of the high-frequency power multi-mode electric toothbrush of the present invention, in which the oscillating brush bar and the oscillating motor cooperate.

[0028] Figure 3 shows a schematic diagram of the oscillating motor in this invention.

[0029] Figure 4 shows a schematic diagram of the internal components of the oscillating motor in this invention, presented in a half-section view.

[0030] Figure 5 shows an exploded view of the oscillating motor in this invention.

[0031] Figure 6 shows a cross-sectional view of the oscillating motor in this invention.

[0032] Figure 7 shows a cross-sectional view of the oscillating motor in this invention from another direction.

[0033] Figure 8 shows a schematic diagram of the structure of the vibrating arm assembly of the oscillating motor in this invention.

[0034] Figures 9A, 9B, and 9C show schematic diagrams of the three states of the oscillating motor under the action of electromagnetic force in this invention. Figures 9A and 9C show the oscillating states in opposite directions, while Figure 9B shows the stationary state when the current is terminated.

[0035] Figures 10A and 10B show two schematic diagrams illustrating the principles of the magnetic poles of the oscillating motor in this invention.

[0036] Figure 11 shows a schematic diagram of the overall structure of the rotating brush rod of the present invention.

[0037] Figure 12 shows an exploded structural diagram of the rotating brush rod of the present invention.

[0038] Figure 13 shows a schematic diagram of the internal structure of the rotating brush rod of the present invention.

[0039] Figure 14 shows an internal schematic diagram of the rotating brush rod of the present invention.

[0040] Figures 15A, 15B, and 15C show schematic diagrams of the three operating states of the rotating brush rod of the present invention.

[0041] Figure 16 shows a schematic diagram of the brush head holder in the rotating brush bar of the present invention.

[0042] Figure 17 shows a partial cross-sectional view of the elastic coupling in the rotating brush rod of the present invention.

[0043] Figure 18A shows a partial cross-sectional view of the elastic fulcrum in the rotating brush rod of the present invention.

[0044] Figure 18B shows a cross-sectional view of another embodiment of the rotary brush bar of the present invention.

[0045] Figures 19A and 19B show schematic diagrams of the compensating spring of the rotating brush rod in this invention.

[0046] Figures 20A and 20B show schematic diagrams of another embodiment of the rotary brush bar of the present invention.

[0047] Figures 21A and 21B show schematic diagrams of another embodiment of the rotary brush bar of the present invention.

[0048] Figures 22A, 22B, 22C and 22D show schematic diagrams of another embodiment of the rotary brush bar of the present invention.

[0049] Figures 23A and 23B show schematic diagrams of the operation of the output shaft of the rotating brush rod of the present invention, where the movement trajectory is an arc circle.

[0050] Figures 24A and 24B show schematic diagrams of the operation of the output shaft of the rotary brush rod of the present invention, where the motion trajectory is a reciprocating parallel line.

[0051] Figure 25 shows an overall schematic diagram of the oscillating brush rod of the present invention.

[0052] Figure 26 shows a schematic diagram of the internal structure of the oscillating brush rod of the present invention.

[0053] Figure 27 shows an exploded view of the oscillating brush rod in this invention.

[0054] Figure 28 shows a schematic diagram of the gap of the oscillating brush rod in this invention.

[0055] Figures 29A, 29B, and 29C show schematic diagrams of the operation of the oscillating brush rod in this invention.

[0056] Figure 30 shows the voltage signal waveform of a typical H-bridge output terminal of the oscillating motor in this invention connected to a purely resistive load.

[0057] Figure 31 shows a schematic diagram of the power current acquisition principle of the oscillating motor in this invention without additional sensors.

[0058] Figure 32 shows the truth diagram of four typical operating states of the H-bridge of the oscillating motor in this invention.

[0059] Figure 33 shows a signal diagram of the H drive bridge of the oscillating motor connected to a purely resistive load and an inductive motor load in this invention.

[0060] Figure 34 shows a schematic diagram of the battery terminal voltage of the oscillating motor in this invention during direct measurement operation, and how the oscillating motor exhibits different swing amplitudes and wave clusters under different loads.

[0061] Figure 35 shows a scatter plot of the relevant data in Figure 34.

[0062] Figure 36 shows a schematic diagram of asynchronous continuous dense voltage sampling of the oscillating motor in this invention.

[0063] Figure 37 shows a schematic diagram of the voltage data of the synchronous sampling method of the oscillating motor in this invention.

[0064] Figure 38 shows a schematic diagram of the principle of the short-circuited H-bridge of the oscillating motor absorbing back electromotive force in this invention.

[0065] Figure 39 shows a comparison of the current signals of the oscillating motor before and after eliminating the back electromotive force in the oscillating motor of the present invention.

[0066] Figure 40 shows a block diagram illustrating the process principle of the constant amplitude correction technology of the oscillating motor in this invention.

[0067] Figure 41 shows a comparison of the swing angle variation curves of the swing motor in this invention with and without compensation when the load changes.

[0068] Figure 42 shows a flowchart of the dynamic servo process for obtaining a constant output swing amplitude of the oscillating motor in this invention.

[0069] Reference numerals: 10. Main body housing; 11. Tail cover; 12. Function button; 13. Control circuit board; 20. Swing motor; 21. Motor bracket; 22. Electromagnetic coil; 23. Shock absorber; 24. Vibration arm assembly; 241. Swing arm; 242. Rotating shaft; 243. Bearing; 244. Connecting frame; 245. Output shaft; 25. Front cover; 26. Sealing cover; 27. Magnet; 30. Battery; 41. Brush rod housing; 421. Brush head holder; 422. Rotating bristles; 423. Fixing frame; 424. Rotating shaft; 425. Mounting bracket. 426. All nails; 43. Compensating spring pad; 44. Swing rod; 45. Elastic fulcrum; 46. Elastic coupler; 47. Drive head; 48. Inner support; 49. Compensating spring; 50. Connecting sleeve; 51. Brush rod housing; 521. Brush rod head; 522. Rotating shaft; 523. Bristle seat; 524. Swinging brush bristles; 53. Swing shaft; 54. Coupler block; 55. Connecting tube; 56. Inner support; 57. Compensating pad. Detailed Implementation

[0070] Referring to Figures 1 and 2, the high-frequency power multi-mode electric toothbrush of the present invention is shown. Figure 1 shows a schematic diagram of an embodiment in which the rotating brush bar cooperates with the oscillating motor in the high-frequency power multi-mode electric toothbrush of the present invention, and Figure 2 shows a schematic diagram of an embodiment in which the oscillating brush bar cooperates with the oscillating motor in the high-frequency power multi-mode electric toothbrush of the present invention.

[0071] Therefore, the high-frequency power multi-mode electric toothbrush includes a main body shell 10, a oscillating motor 20, a battery 30, a rotating brush bar, and an oscillating brush bar. The main body shell 10 is hollow to form an internal space, and its rear end is closed by a detachable tail cap 11. The main body shell 10 contains a control circuit board 13, and multiple function buttons 12 connected to the control circuit board 13 are provided on the side wall. Thus, the operator can provide control signals to the control circuit board 13 through the function buttons 12 to achieve the purpose of controlling the electric toothbrush.

[0072] The front end of the built-in space of the main body housing 10 is provided with a oscillating motor 20. The output shaft 245 of the oscillating motor 20 extends from the front end of the main body housing 10 and is connected to the brush rod located in front of the main body housing 10 to provide power output for the brush rod. The rear end of the built-in space is provided with a battery 30. The battery 30 is electrically connected to the control circuit board 13 and the oscillating motor 20 to provide stable and reliable power output for both.

[0073] In the embodiment shown in Figure 1, the rotating brush rod is detachably connected to the front end of the main body housing 10, and the output shaft 245 extends into the rotating brush rod to provide driving force. In the embodiment shown in Figure 2, the oscillating brush rod is detachably connected to the front end of the main body housing 10, and the output shaft 245 extends into the oscillating brush rod to provide driving force. Thus, the main body housing 10 can be detachably connected to either the rotating brush rod or the oscillating brush rod, thereby combining the advantages of both high-frequency rotating brush rods and high-frequency oscillating brush rods and better improving the applicability.

[0074] Please also refer to Figures 3 to 9C for a better understanding of a specific embodiment of the oscillating motor in this invention.

[0075] In this embodiment, the oscillating motor 20 includes a motor bracket 21, an electromagnetic coil 22, a shock absorber 23, a vibrating arm assembly 24, a front cover 25, and a magnet 27. As can be seen more clearly from the exploded view shown in FIG5 and the cross-sectional views in FIG6 and FIG7, the front end of the motor bracket 21 is provided with a front cover 25 and the rear end is provided with a magnet 27. The rear side of the magnet 27 is also provided with a shock absorber 23, which can isolate the vibration of the oscillating motor 20 from the battery on the rear side, realize the shock absorption function, and avoid the user's comfort being reduced due to excessive vibration during use.

[0076] The motor bracket 21 has an inner cavity to house the vibrating arm assembly 24. The rear outer edge of the inner cavity is covered with an electromagnetic coil 22. Referring to Figure 8, the vibrating arm assembly 24 includes a swing arm 241, a rotating shaft 242, a bearing 243, and a connecting frame 244. The swing arm 241 is a straight iron swing arm with its rear end located in the electromagnetic coil 22 at the rear of the inner cavity. The front part of the swing arm 241 forms a disc portion with a shaft hole through which the rotating shaft 242 passes. The two ends of the rotating shaft 242 are rotatably supported on the motor bracket 21 by the bearings 243. The rear end of the connecting frame 244 covers the front part of the swing arm 241 and forms a cylindrical structure to house the disc portion of the swing arm 241. The front end of the connecting frame 244 is connected to the rear end of the output shaft 245 to transmit the vibration generated by the vibrating arm assembly 244 to the output shaft 245 for output.

[0077] The swing arm 241, rotating shaft 242, and output shaft 245 are integrally formed by plastic secondary injection molding to create a connecting frame 244, thus constituting a vibrating arm assembly. The rotation axis of the rotating shaft 242 is perpendicular to the swing direction of the swing arm 241. The rotating shaft 243 is preferably located in the rotating shaft hole at approximately 2 / 3 of the length of the swing arm 241, so that the rotating shaft and the swing arm are combined in a cross shape. The two ends of the rotating shaft 242 are provided with shaft shoulders that cooperate with the bearings 243. The rear end of the output shaft 245 is provided with at least one concave ring, so that the output shaft 245 and the connecting frame 244 are stably integrally formed after secondary injection molding. The at least one concave ring of the output shaft 245 can effectively prevent displacement of the output shaft under external force.

[0078] Therefore, as a power conversion device that converts electromagnetic energy into mechanical energy, the oscillating motor ultimately outputs a driving torque that is 2-5 times that of a traditional DC motor of the same volume under the same working conditions under the same power consumption conditions, in order to meet the high-frequency oscillation power requirements of electric toothbrushes.

[0079] Referring to Figures 9A, 9B, and 9C, the vibrating arm assembly is housed within the cavity of the device. A space is formed between the rear of the swing arm 241 and the inner wall of the motor bracket 21, allowing the swing arm 241 to swing back and forth by 20 degrees without colliding with the motor bracket. The rear end of the motor bracket 21 forms a stepped portion to accommodate the magnet 27, thereby maintaining a gap of at least 0.2-0.6 mm between the end of the swing arm 241 and the magnet. Thus, the magnet 27 at the tail end can induce a magnetic force on the tail end of the iron swing arm, but there is no physical contact.

[0080] Two magnets are arranged in parallel at the tail of the support, with their magnetized surfaces facing the swing arm. When the two magnets are combined, they are of the same polarity but have different names.

[0081] The front cover 25 of the motor bracket 21 is covered with a sealing cover 26 to achieve a seal. The front cover strengthens the stability of the bearings at both ends of the shaft and provides a limit for the sealing cover.

[0082] The process by which the electromagnetic force of the oscillating motor proposed in this invention is converted into oscillating mechanical energy is as follows:

[0083] 1. Connect a square wave power current with alternating positive and negative polarities to the electromagnetic coil.

[0084] 2. As shown in Figure 9A, assuming that during the positive half-cycle of the square wave, since the electromagnetic coil has an iron swing arm built inside, and the axis of the swing arm is in the same direction as the axis of the electromagnetic coil, the swing arm will be polarized and magnetized under the action of the electromagnetic field. Assuming that the swing arm closest to the magnetic pole is polarized to the S pole at this moment, under the principle of like poles repelling and unlike poles attracting, the swing arm of the vibrating arm assembly will swing in the direction of D1.

[0085] 3. As shown in Figure 9C, when the square wave current switches to the negative half-cycle, the polarity of the electromagnetic coil is reversed, and the current acting on the electromagnetic coil is opposite to that of the positive half-cycle. The magnetic pole induced by the swing arm changes to the N pole. Similarly, under the action of the new electromagnetic force, the swing arm of the vibrating arm assembly will switch from the D1 direction to the D2 direction.

[0086] 4. After the positive and negative half-cycles of current switching are completed, the swing of the motor's vibrating arm assembly constitutes a complete vibration cycle. The swing frequency of the vibrating arm assembly depends on the frequency of the square wave current of the drive coil. In this embodiment of the invention, the electromagnetic coil preferably operates at 140Hz-350Hz. The strength of the swing angle of the vibrating arm assembly can be adjusted by the duty cycle of the square wave. The swing angle is proportional to the size of the duty cycle.

[0087] The swing arm 241 is supported by a ferromagnetic material. Since the working frequency can be as high as 350Hz, the swing arm 241 is made of stacked silicon steel sheets with high frequency and low eddy current loss.

[0088] As shown in Figure 10A, the magnet 27 of this invention can be composed of two independent magnets M1 arranged to form magnetic poles, or as shown in Figure 10B, it can be constructed using a coplanar multi-pole magnetization process, employing only one magnet M2 to simultaneously magnetize and polarize the N and S poles on the same plane. The N and S poles being aligned with the polarities of the two magnets is sufficient to meet the requirements of this invention.

[0089] Among them, the sensorless synchronous drive pulse detection battery voltage technology is adopted. It relies on a specific drive pulse cycle to monitor the change of drive current caused by the change of motor dynamic impedance. Combined with the corresponding algorithm, the drive power is compensated in real time based on the monitored motor operating conditions to achieve constant swing output.

[0090] In one embodiment of this oscillating motor, a constant amplitude control method is involved. The typical driving voltage waveform is a square wave, with its frequency matching the output oscillation frequency. Theoretically, under constant voltage conditions, when the motor is operating at full power, the duty cycle of the square wave should be 100%. In practical applications, the most basic driving power device is an H-bridge consisting of four FETs. The H-bridge switches rapidly between positive and negative voltages at its output terminal as the input signal changes. Due to the time lag in FET switching, switching at a 100% duty cycle would result in all four FETs of the H-bridge conducting simultaneously, causing an internal short circuit and damaging the H-bridge drive. This fastest response interval is usually called the dead zone of the H-bridge drive. Therefore, the H-bridge must avoid operating in the dead zone, and power supply to the motor must be stopped during this interval. Considering the dead zone, the maximum duty cycle of the square wave is typically 98%–99%, not 100%.

[0091] If the duty cycle of the pulse is reduced in the opposite direction, the effective power of the drive will decrease in the opposite direction, and the swing amplitude of the oscillating motor will decrease accordingly. The mechanism of changing the output power by adjusting the duty cycle of the pulse serves as the theoretical basis for the output rate compensation of the oscillating motor mentioned in this invention.

[0092] Figure 30 shows a typical voltage signal waveform when the output of an H-bridge is connected to a purely resistive load. In the figure: S1 is the effective working pulse of the positive half-cycle, S2 is the effective working pulse of the negative half-cycle, t12 and t22 are the working stop cycles of the positive and negative half-cycles, respectively, which include the necessary dead zone control time and the stop time for adjusting the duty cycle of the entire pulse. t is a complete drive cycle, t = S1 + S2 + t12 + t22; assuming S1 = S2 and t12 = t22, the positive and negative half-cycles are completely symmetrical; the duty cycle is Duty = S1 / (t12 + S1) × 100% or Duty = S2 / (t22 + S2) × 100%. In actual control, the power control of the drive can be achieved by synchronously adjusting the proportion of t12 and t22 in the entire pulse t, i.e., the duty cycle parameter Duty. Obviously, the larger the proportion of t12 and t22, the smaller the output power. Controlling the output power by adjusting the duty cycle ratio is the theoretical basis of the motor control technology of this invention.

[0093] Before discussing how to implement the constant amplitude control theory of the motor mentioned in this invention, we will first explain the principle and method of acquiring power current without additional sensors. As shown in Figure 31, a schematic diagram of the principle of acquiring power current without additional sensors is displayed. In this diagram, BT represents the battery pack, V is the standard battery, and R0 is the internal resistance of the battery pack; MCU is the microprocessor of the circuit control unit, which contains an analog-to-digital converter labeled ADC and a reference voltage reference source for the ADC labeled Vref; S1 to S4 are the output drive signal ports of the MCU dedicated to the H-bridge; H is the H power drive bridge composed of two pairs of complementary FETs; M is the oscillating motor involved in this invention; and I is the power current.

[0094] Figure 32 shows the truth values ​​for four typical operating states of the H-bridge.

[0095] Among them, the current sampling required for the constant amplitude technology involved in this invention has two key aspects:

[0096] 1. Utilizing the internal resistance R0 of the battery pack, during power drive, the changing power current I will inevitably generate a changing voltage drop Vdp in R0. The change in load current can be reflected by detecting Vdp through the MCU control unit, i.e., Vdp = R0 × I.

[0097] 2. To simplify the hardware design, a microprocessor with a built-in analog-to-digital converter (ADC) and a voltage reference source (Vref) is selected. This allows the power current change to be calculated directly without the need for additional external designs.

[0098] Unless otherwise specified, the power current change detection discussed in this article is based on the method of detecting the change in voltage drop Vdp of R0.

[0099] The following sections will further explain the implementation method and process of constant amplitude compensation in two parts.

[0100] The signals from a purely resistive load and an inductive motor load connected to the H-drive bridge exhibit significant differences, as shown in Figure 33. In the figure, the solid line CV1 represents the waveform of a purely resistive load, while the dashed line represents the waveform of a oscillating motor with an inductive load. The obvious difference between these two sets of waveforms is the presence of a peak ringing (marked as D) in each working pulse. Furthermore, under the influence of the inductive load, the horizontal line of a standard rectangular square wave changes to a slope line from the starting point a to the ending point b of each effective working waveform.

[0101] When the motor is connected to the drive end, the square wave exhibits significant overshoot and ringing. This is mainly due to the stopping cycle (dead zone cycle + power adjustment cycle), when power supply to the motor coil stops. Since the coil is an inductive load, it generates a back electromotive force (EMF). Additionally, the swing arm continues to cut the magnetic lines of force generated by the magnet due to inertia, creating a variable impedance to the coil. The superposition of the coil's back EMF and the variable impedance on the power supply directly affects the smoothness of the square wave's rising edge and pulse width.

[0102] After the coil is de-energized, the swing arm continues to oscillate due to inertia. Assuming the oscillation frequency remains constant, the larger the amplitude, the greater the velocity at which the magnetized swing arm cuts the magnetic field lines, and the greater the impact on the variable impedance generated by the coil. Clearly, if the instantaneous current related to the variable impedance can be measured, the current oscillation linear velocity of the swing arm can be mapped, i.e., the relative change in the current output swing. This idea is the most important theoretical basis for the real-time amplitude measurement involved in the constant amplitude drive technology mentioned in this invention.

[0103] To reduce the impact of stray electromagnetic interference on signal detection, the swing correlation data detection mentioned in this invention is not located at the motor drive output end, but rather the instantaneous voltage change at the battery terminal is measured directly. This voltage change has a corresponding mapping relationship with the current change at the motor drive end.

[0104] Figure 34 shows the battery terminal voltage measured directly during operation. Under different loads, the oscillating motor exhibits different oscillation amplitudes and waveforms. The solid curve CV1 in the figure represents the waveform under no-load conditions, while the dashed curves CV2, CV3, CV4, and CV5 represent the waveforms exhibited under increasing loads. It can be observed that the battery terminal voltage changes with the load at a certain time interval of each drive pulse. As shown in the attached figure, the correlation between motor load and voltage is clearly observed in the t1-t2 interval; the heavier the load, the higher the voltage. The summarized pattern is:

[0105] Load: CV5 > CV4 > CV3 > CV2 > CV1;

[0106] Pulse end voltage: V5>V4>V3>V2>V1.

[0107] Figure 35 shows the data as a scatter plot. In the figure, the V-axis is the battery terminal voltage, and the D-axis is the swing angle of the pendulum. The heavier the load, the smaller the swing angle of the pendulum.

[0108] V5 to V1 represent 5 sampling points, and curve a is the curve formed by connecting the actual sampling points in series. The attached figure clearly shows a strong correlation between the voltage at the sampling points and the angle of oscillation under different loads. To simplify the computational load on the microprocessor, the above sampling data can be fitted with a straight line b using the least squares method.

[0109] The instantaneous voltage change U at the battery terminals is affected by two important factors: U = Ub + Ur. Ub is the back electromotive force generated during the motor's power-off and stop cycle, while Ur is the change in the dynamic inductive reactance of the coil caused by the change in the swing amplitude of the vibrating arm. This change in dynamic inductive reactance directly affects the rate of current conduction in the coil, essentially creating a changing impedance. Ultimately, this change in coil impedance affects the performance of the rising edge of each pulse at the motor coil terminals.

[0110] Therefore, as long as the voltage change component caused by impedance change at the rising edge of each pulse can be effectively separated, the current motor swing data can be quantified.

[0111] To better separate the changing impedance of the motor coil, appropriate and accurate current sampling points are crucial. As can be seen from the waveform, unlike conventional sampling methods, the conventional approach for typical DC motors ignores pulse synchronization information and uses continuous, equidistant, dense sampling. The longer the sampling period, the more stable the weighted average, thus better reflecting the relationship between voltage and load. However, this asynchronous averaging method has proven ineffective for brushless motors driven by pulse commutation. The voltage results obtained from continuous sampling without pulse synchronization show no significant correlation with load changes.

[0112] Figure 36 illustrates the performance of asynchronous continuous dense voltage sampling in a brushless motor: In the figure: V-axis: voltage scalar, T-axis: time scalar, S1~Sn is the timing sequence of asynchronous continuous sampling, t2 is the sampling period, P1~pn is the periodic signal of voltage change observed at the battery terminal, which is obviously phase-related and synchronous with the motor drive pulse, t1 is the motor drive pulse period, and D1~Dn is the sampled voltage value.

[0113] As shown in the figure, if t1 and t2 are out of sync, the sampling positions of D1 and D5 differ significantly from the pulse start and end positions. D1 is closer to the beginning of pulse P1, while D5 is closer to the end of pulse P3, resulting in a large difference between these two sampled values. Therefore, a weighted average method can be used to average the data: Avg = (D1 + D2 + Dn…) / n…. However, the average value Avg fails to accurately capture the data that correctly correlates the load and voltage. Therefore, traditional asynchronous voltage sampling is not suitable for the oscillating motor operating conditions mentioned in this invention.

[0114] Figure 37 illustrates the performance of voltage data in the synchronous sampling method: In the figure: V-axis: voltage scalar, T-axis: time scalar, S1~Sn is the timing sequence of asynchronous continuous sampling, t2 is the sampling period, P1~pn is the voltage change periodic signal observed at the battery terminal, which is obviously phase-dependent and synchronous with the pulse. t1 is the motor drive pulse period, and D1~Dn are the sampled voltage values.

[0115] As can be observed from Figure 37, if t1 and t2 are synchronized, the sampling positions of D1, D2, D3...Dn are consistent with the pulse start and stop positions. Assuming that the weighted average method is used to average the data: that is, Avg=(D1+D2+Dn…) / n…, the average value Avg can correctly capture the data that correctly correlates the load and voltage. Therefore, synchronous voltage sampling is the preferred current sampling scheme for the oscillating motor mentioned in this invention.

[0116] Based on the data in the two figures above, the difference between the traditional simple weighted average current sampling mode and synchronous sampling is clearly explained. The oscillating motor, in a broad sense, belongs to the category of brushless motors. Both are driven by power pulses that switch between positive and negative polarity pulses at high frequency. The sampling mode that is synchronized with the pulse phase must be used to analyze the current information related to the load.

[0117] Even after synchronous sampling, additional technical means are still needed to filter out the back electromotive force signal generated by unnecessary coils that affect the load current performance in order to further improve signal quality.

[0118] The overcharge amount at the rising edge of the pulse contains not only information about the coil's dynamic impedance but also the back electromotive force (EMF) generated after the coil is de-energized. If the overcharge information of each pulse rising edge is used directly to quantize the swing amplitude relationship without considering the influence of the back EMF on signal superposition, the presence of the back EMF will more or less reduce the accuracy of quantization. To eliminate the influence of the back EMF on the overcharge of each pulse rising edge, the motor coil can be momentarily short-circuited using an H-bridge during each drive stop cycle, allowing the back EMF to be released quickly. Examples demonstrate that eliminating the back EMF enables more sensitive monitoring of motor swing amplitude changes and improves the signal-to-noise ratio.

[0119] Therefore, Figure 38 is a schematic diagram of the principle of short-circuited H-bridge absorbing back EMF. In the figure: F1 to F4 are two pairs of complementary NP-channel FETs forming an H-bridge to drive the oscillating motor. M is the oscillating motor. Before the motor current is detected and the drive power is disconnected, the inputs of S1 and S2 are set to high level, and F1 and F2 enter the cutoff state. The inputs of S3 and S4 are also high level, and F3 and F4 are turned on. After F3 and F4 are turned on, F3, F4 and M form a loop, which short-circuits the back EMF generated at both ends of the motor M, generating a short-circuit current loop C. The back EMF is converted into heat energy and dissipated on the motor coil.

[0120] Once the back electromotive force is absorbed, S3 and S4 switch to high level and enter the cutoff state, starting the MCU's ADC conversion for current detection.

[0121] Figure 39 shows a comparison of current signals before and after eliminating back EMF in the oscillating motor. In the figure: V axis: voltage scalar, T axis: time scalar, P1 to P3 show three sets of pulse period signals, CV1 solid curve is the voltage curve after eliminating back EMF using short-circuit technology, CV2 dashed curve is the voltage curve affected by back EMF, Ts is the important area containing load change information, C is the ringing peak signal that appears when back EMF is not eliminated by short-circuiting, and a is the area with a large influence of back EMF.

[0122] Since the shadowed area caused by the ringing peak of the signal due to the back electromotive force in the a region has a significant impact on the effective load signal in the Ts interval, absorbing the ringing peak using technical means is of positive significance for analyzing the load signal.

[0123] Short-circuiting to eliminate back EMF is beneficial for analyzing changes in the dynamic impedance of the coil, but it can also have a negative impact on the motor. When the coil current is short-circuited, heat will be generated in the coil, causing the coil operating temperature to rise. Whether to use back EMF elimination technology or choose a reasonable short-circuit sequence can be decided based on the actual application.

[0124] Once valid amplitude quantization data is obtained, this data can be used to adjust the duty cycle of the drive pulse in real time. When the amplitude is lower than the set value, the pulse duty cycle is continuously increased to increase the drive power and improve the amplitude; conversely, the duty cycle is continuously decreased to reduce the drive pulse power and decrease the amplitude. By dynamically monitoring the amplitude value and dynamically adjusting the pulse drive power in real time using the methods discussed above, a stable output amplitude can be obtained under load variations.

[0125] Figure 40 is a block diagram illustrating the process principle of the constant amplitude correction technology involved in this invention. In specific implementations, besides addressing the battery voltage change related to the swing amplitude, it is also necessary to correctly select appropriate sampling and adjustment frequencies. This is because ADC data acquisition and processing consumes resources, and overly dense data sampling can interfere with the stability of the driving pulse phase, causing phase jitter, resulting in irregular oscillations and abnormal noise on the motor swing shaft. The density of the adjustment pulse duty cycle also needs to be appropriate, as the motor swing shaft has rotational inertia and response time requirements. Overly dense adjustments will weaken the analyzed useful amplitude information, leading to overshoot and overshoot oscillations, making normal control impossible. Overly sparse adjustments will result in sluggish control response and unsatisfactory compensation effects. Generally, the following factors should be considered in practical control applications:

[0126] 1. Synchronization point with motor signal: The implementation example proves that sampling data is most stable and has a high signal-to-noise ratio when the pulse is about to end.

[0127] 2. Back EMF Activation Duration and Density: Back EMF absorption should not be activated for every pulse. It should only be enabled before detecting the battery voltage and immediately disabled after detection. Otherwise, a large amount of heat will be dissipated into the motor coils, causing the motor operating temperature to rise sharply. Similarly, the absorption duration is also a key point in controlling heat, and the specific duration should be determined based on actual conditions and experimental results.

[0128] 3. Battery voltage sampling: Sampling should not be performed for every pulse. In the example sub-test, sampling once every 20 pulses is optimal. Overly frequent sampling will cause phase jitter and abnormal noise in the motor.

[0129] 4. Adjusting the frequency of the motor drive pulse duty cycle: This also needs to be reasonable. Too frequent corrections will result in overshoot oscillation, while too sparse compensation will lead to sluggish response and unstable swing after load changes.

[0130] Therefore, the control method includes the following steps:

[0131] Step 1: Synchronize the output pulse (which can be the square wave pulse mentioned above);

[0132] Step 2: Initiate back electromotive force absorption;

[0133] Step 3: Synchronously collect battery voltage;

[0134] Step 4: Analyze load-related variables;

[0135] Step 5: Calculate the correction amount;

[0136] Step 6: After correcting the drive duty cycle, return to Step 1.

[0137] Figure 42 shows a flowchart of the dynamic servo process signal processing for obtaining a constant output swing of the motor, as mentioned in this invention.

[0138] It includes the following steps:

[0139] Step 1: After the interrupt response, determine whether the 20-pulse interval is met. If yes, proceed to Step 2; otherwise, exit.

[0140] Step 2: Determine if it is a stop cycle. If yes, proceed to Step 3; otherwise, exit.

[0141] Step 3: Start back EMF absorption, determine whether the drive pulse has ended; if yes, proceed to step 4; otherwise, exit.

[0142] Step 4: Collect the battery voltage. If the voltage value is lower than the previous value, proceed to step 5; otherwise, proceed to step 6.

[0143] Step 5: Increment the duty cycle of the drive pulse and then exit;

[0144] Step 6: Is the voltage value greater than the previous acquisition value? If yes, decrease the duty cycle of the drive pulse and exit; otherwise, exit directly.

[0145] The above exit method directly exits the interrupt response.

[0146] In embodiments of the present invention, after system initialization, the initial pulse duty cycle without compensation is preset to 45%, and to 98% under maximum compensation.

[0147] Figure 41 compares the swing angle variation curves with and without compensation under load changes. The vertical axis represents the swing angle exhibited by the swing axis, and the horizontal axis represents the force applied to the swing axis. Curve CV1 represents the output performance without compensation, and CV2 represents the performance after real-time dynamic compensation. As can be seen from the figure, the swing amplitude's ability to withstand load changes is significantly improved after compensation.

[0148] Figures 11 to 24B show embodiments of the rotating brush rod of the present invention. Referring to Figures 11, 12, 13 and 14, an embodiment of the rotating brush rod of the present invention is shown. Figure 11 shows an overall structural schematic diagram of the rotating brush rod of the present invention, Figure 12 shows an exploded structural schematic diagram of the rotating brush rod of the present invention, and Figures 13 and 14 show detailed schematic diagrams of the internal structure of the rotating brush rod of the present invention.

[0149] As shown in Figures 11, 12, and 13, the rotating brush handle includes a brush handle housing 41, an inner support 47, a rotating brush head assembly, and a power transmission assembly. The brush handle housing 41 is hollow and its rear end is detachably connected to the main unit of the electric toothbrush. The rear part of the brush handle housing 41 is formed into a trumpet shape and accommodates the inner support 47. The inner support 47 is trumpet-shaped and hollow, adapted to the inner cavity of the brush handle housing 41, to form an inner space for the built-in power transmission assembly. The front end of the brush handle housing 41 forms a circular groove for accommodating the rotating brush head assembly.

[0150] Referring also to the installation diagram in Figure 1, a specific embodiment of the rotating brush handle of the present invention is shown in an electric toothbrush. In this embodiment, the rear end of the brush handle housing 41 is detachably connected to the front end of the main body housing 10, the rear end of the power transmission assembly is connected to the output shaft 245 of the oscillating motor 20, and the front end is connected to the rotating brush head assembly, thereby transmitting the output power of the oscillating motor 20 to the rotating brush head assembly.

[0151] Specifically, the rotating brush head assembly includes a brush head base 421 and rotating bristles 422. The brush head base 421 is rotatably disposed in a circular groove at the front end of the brush handle housing 41. Multiple rotating bristles 422 for cleaning are embedded at its upper end, and a base is provided at its lower end. In the illustrated embodiment, the brush head base 421 is connected to the brush handle housing 41 via a rotating assembly. The rotating assembly includes a fixing frame 423, a rotating shaft 424, and a safety pin 425. The base of the brush head base 421 provides a fixing frame. 423 is a through hole. The side of the fixing frame 423 is fixed to the brush rod housing 41 by a safety pin 425. The middle of the fixing frame 423 is provided with a through hole for the rotating shaft 424 to pass through. Both ends of the rotating shaft 424 extend into the brush head seat 421. Thus, the fixing frame 423 is fixed to the brush rod housing 41 by the safety pin 425, while the brush head seat 421 rotates relative to the fixing frame 423. This allows the brush head seat 421 to rotate within the circular groove through the power transmission of the rotating power assembly.

[0152] Optionally, a compensation spring pad 426 is provided between the base of the brush head holder 421 and the brush rod housing 41 to provide compensation during rotational movement.

[0153] The power transmission assembly includes a rocker arm 43, an elastic fulcrum 44, an elastic coupling body 45, a drive head 46, a compensating spring 48, and a connecting sleeve 49. The front end of the rocker arm 43 is provided with a drive head 46 for driving the brush head seat 421. In the embodiments shown in Figures 12 to 14, the drive head 46 is a protruding head. Referring also to Figure 16, the base of the brush head seat 421 has a groove 4211 that meshes with the protruding head, so that the protruding head 46 can extend into and engage with the brush head seat 421. The toothed groove 4211 enables the power transmission between the two. The middle part of the swing rod 43 is elastically supported on the front inner wall of the inner bracket 47 by the elastic fulcrum 44. A compensating spring 48 is sleeved between the drive head 46 and the elastic fulcrum 44. The connecting sleeve 49 is embedded in the rear end of the inner bracket 47. The rear end of the swing rod 43 extends into the front end of the connecting sleeve 49. The rear end of the connecting sleeve 49 is connected to the output shaft 245 of the swing motor through the elastic coupling body 45 to transmit power.

[0154] Therefore, the brush head seat of the rotating brush bar is round or elliptical. The movement of the brush head seat is a rotary joint. The center of rotation is the center of the brush head seat around the rotation axis 424. The circular brush head seat moves in the form of reciprocating rotations in opposite directions. The rotation angle range is usually 10-120 degrees, and the conventional reciprocating rotation frequency is 80-130Hz.

[0155] In the specific embodiments shown in Figures 12 to 14, the rotating brush bar can reliably operate in the 80-350Hz range and maintain an effective load swing angle of more than 20 degrees.

[0156] The free length of the compensation spring 48 is greater than the distance between the elastic fulcrum and the drive head. When the compensation spring 48 is compressed, it generates a reaction force that pushes the drive component toward the brush head seat. The connecting sleeve 49 is a trumpet-shaped sleeve, and the elastic coupling body 45 is a through-hole elastic body. The protruding end of the output shaft 245 is contained by the elastic coupling body 45.

[0157] Thus, as shown in Figures 15A, 15B, and 15C, when the output shaft oscillates, the power is coupled through the connecting sleeve 49 and the elastic coupling body 45. The swing arm rotates around the elastic fulcrum 44, and the rotation of the swing arm drives the drive component 46 to follow suit. The drive component 46 further drives the brush head seat to rotate at high speed. When the swing arm oscillates in the opposite direction, the direction of motion of the brush head seat also changes in the opposite direction. The oscillation of the swing arm in both directions constitutes a complete motion cycle. The mechanical principle of the swing arm's action on the brush head seat is essentially a simple lever principle. The position of the elastic fulcrum at the top of the inner support determines the magnitude of the brush head output swing angle and output torque. The closer the elastic fulcrum is to the brush head, the smaller the brush head seat swing angle and the greater the brush head seat torque; conversely, the further away the elastic fulcrum is, the larger the brush head seat swing angle and the smaller the brush head torque.

[0158] As shown in Figure 17, the front end of the connecting sleeve 49 is tightly fitted with the rear end of the swing rod 43, and the rear end accommodates the elastic coupling body 45. The elastic coupling body 45 has a concave inner ring 451 in the middle. The connecting sleeve 49 has a corresponding inner protrusion that extends into the concave space of the elastic coupling body 45. The fit between the concave inner ring 451 and the inner protrusion can better cooperate with the output shaft of the swing motor for power transmission.

[0159] As shown in Figure 18A, in a preferred embodiment of the present invention, the elastic fulcrum 44 is provided with a concave ring 441 in the middle, and the front end of the inner support 47 is provided with a concave convex part that extends into the concave space of the elastic fulcrum 44. Thus, the concave ring 441 of the elastic fulcrum 44 is tightly fitted with the middle part of the swing rod 43, and the outer edge of the elastic fulcrum 44 is also in contact with the inner support 47, so that the swing rod 43 can swing stably with the elastic fulcrum 44 as the fulcrum.

[0160] In another embodiment shown in Figure 18B, a different form of the power transmission assembly of the rotating brush rod of the present invention is illustrated. In this embodiment, the structure of the connecting sleeve 49' and the elastic coupling body 45' differs from that in Figures 1 to 4. In this embodiment, the elastic coupling body 45' has an outer protrusion corresponding to the outer edge of the concave annular protrusion 451 to extend into a hollow groove of the connecting sleeve 49', so as to achieve stable coupling between the connecting sleeve 49' and the elastic coupling body 45'. This structure can better achieve power coupling between the connecting sleeve 49' and the elastic coupling body 45'.

[0161] As shown in Figures 19A and 19B, a compensating spring 48 is installed between the elastic fulcrum and the drive head. The free length L2 of the compensating spring 48 is greater than the distance L1 between the elastic fulcrum and the drive head. Therefore, when the compensating spring 48 is compressed, it will generate a constant reaction force that pushes the drive head towards the brush head seat, ensuring that the two are in close contact at any given time. This allows for the elimination of the gap between the two at any given time. Thus, the compensating spring 48 can be referred to as an elastic compensation gap elimination mechanism. This elastic compensation gap elimination mechanism will improve performance under the following operating conditions:

[0162] 1. During brushing, the brush head holder may lose contact with the drive head due to load changes, creating a gap. At this moment, the elastic compensation gap elimination mechanism will activate, pressing the contact surface together under the reaction force of the compensation spring.

[0163] 2. During user use, the rolling friction between the drive head and the brush head seat caused by the abrasive in the toothpaste will cause wear on the mating surfaces and will also lead to the formation of a clearance. At this time, the elastic compensation clearance elimination mechanism will come into play.

[0164] 3. During user use, the brush head holder spindle and spindle fixing bracket will also experience wear due to the abrasive action of toothpaste, resulting in a clearance. Due to the existence of the compensating spring reaction force, the worn components will be tightened, thus solving the noise and abnormal sounds caused by the impact of the gap between high-speed moving components.

[0165] 4. The rocker arm and drive head are separate components. In the actual manufacturing and assembly process, there will be tolerances, which will cause gaps in the fit. At this time, the elastic compensation gap elimination mechanism will come into play.

[0166] 5. There may be errors between the theoretical design of the shape and the actual manufacturing. These errors may also cause gaps in the fit between the protrusion and the groove of the brush head seat. At this time, the elastic compensation gap elimination mechanism will come into play.

[0167] In summary, the elastic compensation and backlash elimination mechanism formed by the compensating spring 48 can effectively stabilize the output angle and torque during brushing, reduce noise, and effectively improve service life.

[0168] Even more preferably, since the brush handle's moving parts operate under conditions of toothpaste abrasive slurry for extended periods, in addition to selecting high-wear-resistant materials for the components, a well-designed meshing profile between the drive head and the brush head holder should theoretically ensure maximum meshing area throughout the entire motion cycle. This helps reduce meshing pressure and improves wear resistance. Furthermore, it should maximize rolling friction between the meshing surfaces throughout the entire friction cycle, minimizing sliding friction, thus further enhancing wear resistance.

[0169] In a further preferred embodiment, a conventional involute profile curve is preferred to solve the above problems. The protrusion and groove 4211 are involute tooth profiles, thereby ensuring that the meshing friction type throughout the process is rolling friction. To maximize the meshing area, the largest module and the largest tooth thickness are selected as much as possible.

[0170] In this embodiment, besides using an involute tooth profile to solve the meshing problem between the protrusion and groove of the brush handle, other contour shapes can also be used, such as a cylindrical protrusion and a trapezoidal groove. Because this invention incorporates a compensating spring, a constant force pushes the protrusion towards the brush head seat. Theoretically, there is no gap during the entire movement of the protrusion and the meshing with the groove. However, compared to the involute tooth profile, its movement involves sliding friction, therefore its theoretical lifespan is shorter.

[0171] Regarding the implementation of the driving head and passive component discussed in this invention, the actual design requirements can be considered. As shown in the embodiments of Figures 20A and 20B, the front end of the driving head 46 can be formed as an active groove 46', and the brush head seat 42 is provided with a corresponding passive boss 4212. The active groove 46' of the driving head 46 can be a single tooth or a multi-tooth shape. Such variations in form fall within the scope of this invention.

[0172] In another embodiment of Figures 21A and 21B, the head of the drive head 46 is formed with a cylindrical protrusion 46”, and the brush head seat 42 is provided with a corresponding receiving groove 4213, and the front end of the cylindrical protrusion 46” is formed into a cylindrical shape.

[0173] In another embodiment of Figures 22A, 22B, 22C and 22D, the head of the drive head 46 is formed with a U-shaped groove 46”', and the brush head seat 42 is provided with a corresponding passive cylinder 4214.

[0174] The base of the brush head holder 421 is a frame that can accommodate the fixing frame 423. After the fixing frame is correctly installed, it penetrates the brush head base. The rotating shaft 424 is fitted with the fixing frame by interference fit, with no relative movement. After the two ends of the rotating shaft 424 extend out, they are fitted with the base by clearance fit, forming two independent coaxial rotating motion pairs.

[0175] The safety pin 425 is perpendicular to the axis of the rotating shaft 424. The rotating brush head assembly is securely locked to the brush rod housing by transverse locking through the transverse hole on the brush rod housing 41 and the hole on the side of the fixing bracket 423. The reason for this transverse device of the safety pin is to prevent the main body from falling vertically, causing the safety pin to be impacted, resulting in unsafe damage such as cracking, loosening, denting, etc., which could lead to the risk of the brush head assembly falling off.

[0176] As shown in Figures 23A and 23B, Figure 23A is a schematic diagram of the output shaft of the oscillating motor in the present invention in a stationary state, and Figure 23B is a schematic diagram of the output shaft swinging left and right. The output shaft swings around the origin O, P1 and P2 are the extreme positions of the two ends that can swing, A is the maximum angle that can swing, and B represents the arc-shaped motion trajectory formed by the coupling point under the swing. Thus, the motion trajectory of the power coupling point (output shaft) at the rear end of the swing shaft 53 is an arc circle, which coincides with the rotation center.

[0177] As shown in Figures 24A and 24B, Figure 24A is a schematic diagram of the output shaft in a stationary state, and Figure 24B is a schematic diagram of the output shaft swinging left and right. The output shaft in the figure moves in parallel and does not swing in an arc, which is another example of the oscillating motor mentioned in this invention. Whether the motor shaft swings or oscillates in parallel, it can meet the requirements of the toothbrush head driving power source mentioned in this invention. P1 and P2 are the extreme positions of parallel oscillation, and D is the stroke of the oscillation.

[0178] Therefore, the main working mechanism of the rotating brush rod of the present invention is as follows:

[0179] 1. The main unit of the electric toothbrush provides reciprocating oscillation torque through the output shaft. The trumpet-shaped sleeve at the end of the swing arm, the embedded connecting sleeve 49, and the elastic coupling body 45 form a coupling. The output shaft of the main unit achieves power coupling with the inner hole of the connecting sleeve 49 and the elastic coupling body 45, which are made of elastic material, thereby driving the swing arm to oscillate back and forth.

[0180] 1.1 The elastic coupling body 45 is designed with a concave ring 451 in the middle. The entire main shaft extends into the concave ring 451 and makes line contact with it to achieve no interference during the swing process and ensure effective power coupling.

[0181] 1.2 The connecting sleeve 49 and the elastic coupling body 45 can also be made of rigid plastic or other materials. In this embodiment of the invention, an elastic material is selected, which can effectively absorb the noise generated by the impact force of the swing arm on the swing arm when the main unit output shaft swings and reverses.

[0182] 1.3 The hardness of the connecting sleeve 49 and the elastic coupling body 45 needs to be moderate; if it is too low, it will affect the dynamic coupling effect of the swing arm, sacrificing the final output torque performance of the brush head seat.

[0183] 2. The elastic fulcrum at the middle of the swing arm and the top of the inner bracket forms a lever fulcrum. When the coupling swings, the drive head at the other end of the swing arm swings in the opposite direction. The drive head and the brush head seat interlock, ultimately driving the brush head to swing around the central rotation axis.

[0184] 2.1 A concave ring 441 with a convex annular surface is set inside the elastic fulcrum constituting the fulcrum. The minimum diameter of the convex surface of the concave ring 441 is slightly larger than or equal to the outer diameter of the rocker arm, so as to allow the rocker arm to slide axially within the hole. The concave ring 441 can effectively prevent interference with the bushing during the swing of the rocker arm, thus avoiding loss of power.

[0185] 2.2 The material for the elastic fulcrum can also be rigid plastic. This embodiment of the invention specifically uses an elastic rubber body to effectively buffer and absorb noise and abnormal sounds generated by the collision of components due to gaps during swinging. The hardness of the elastic fulcrum should be moderate and not too low; otherwise, excessive deformation of the elastic body under heavy load will cause significant changes in the fulcrum position or displacement, resulting in a loss of the swing stroke and insufficient power at the end of the swing arm. This embodiment of the invention preferably uses nitrile rubber with a hardness of 80-90 degrees to make the elastic fulcrum.

[0186] 3. In one embodiment, the protrusion is enclosed by the groove of the brush head seat. When the protrusion swings, the groove is pushed and displaced. Since the brush head seat has a rotating shaft 424 forming a rotating pair, the displacement of the groove is ultimately manifested as the repeated rotation of the brush head causing the brush bristles on the brush head to rotate and swing.

[0187] 3.1 Theoretically, the ideal fit between the boss and the groove should be a seamless match throughout the entire reciprocating oscillation process. The friction between the surface of the boss and the groove of the brush head seat should be rolling friction, not sliding friction. In this case, material wear caused by dynamic coupling is minimized, and coupling power loss is minimized. In this embodiment of the invention, a traditional involute tooth shape is preferred to achieve the envelope shape of the boss and groove fit. The center of the pitch circle of the boss is the fulcrum of the swing arm, which is also the annular boss of the elastic body at the top of the inner support of the brush arm. The central axis of the brush head seat is the center of the pitch circle of the groove in the brush head seat. The ratio of the pitch circle of the boss to the pitch circle of the brush head seat determines the torque transformation ratio of the dynamic coupling, ultimately affecting the swing angle and output torque of the brush head seat. Theoretically, the distance from the fulcrum of the swing arm to the fit point of the boss is directly proportional to the swing angle of the brush head seat and inversely proportional to the output torque of the brush head seat.

[0188] 3.2 The fit between the boss and the brush head seat groove adopts an involute envelope, and ideally, the entire reciprocating motion matching process is a gapless fit. Therefore, theoretically, the operating noise caused by the gap in the fit between the boss and the brush head groove can be completely eliminated.

[0189] 3.3 The boss and groove of the present invention can be selected to have a single tooth or multiple tooth engagement. In the embodiments of the present invention, considering wear resistance and the applicable brush head seat swing angle range, a single boss and a single groove structure for the brush head seat is preferred. This can maximize the tooth profile module and improve the actual strength and wear resistance of the boss.

[0190] 3.4 In this embodiment of the invention, in order to improve the wear resistance of the fit between the boss and the brush head seat, the tooth thickness of the boss is increased as much as possible to reduce the interaction pressure of the surface area. Working space for the thick teeth is reserved in the design.

[0191] 4. In the embodiments of the pendulum rod mentioned in this invention, a stainless steel rod with good rigidity is preferred. During the implementation and verification process, it was found that if the rigidity of the pendulum rod is insufficient, under the action of high-frequency oscillation force, the flexural resonance deformation of the pendulum rod will partially offset the swing angle, which will ultimately result in a smaller swing angle and output torque of the brush head, thus losing the expected performance.

[0192] 5. In this embodiment of the invention, the safety pin device is perpendicular to the axis of the brush handle, rather than being coaxial as in the traditional method. This effectively prevents the safety pin from collapsing towards the main axis of the brush head holder due to direct impact force when the brush head falls to the ground, causing the brush head holder to break or the safety pin hole to crack, thus posing a safety risk of the brush head holder falling off during use. The perpendicular mounting of the safety pin to the brush shaft effectively avoids these problems and improves the safety factor of the brush head holder under various operating conditions.

[0193] Referring to Figures 25 to 28, the oscillating brush rod of the present invention is shown, wherein Figure 25 shows an overall external schematic diagram of the oscillating brush rod of the present invention, Figure 26 shows an internal structural schematic diagram of the oscillating brush rod of the present invention, Figure 27 shows an exploded schematic diagram of the oscillating brush rod of the present invention, and Figure 28 shows a gap schematic diagram of the oscillating brush rod of the present invention.

[0194] The oscillating brush handle of this invention includes a brush handle housing 51, an internal support 56, an oscillating brush head assembly 52, and an oscillating power transmission assembly. The rear end of the brush handle housing 51 is detachably connected to the electric toothbrush, and more specifically, to the front end of the main body housing of the electric toothbrush. The brush handle housing 51 is formed in a hollow, flared shape, and its rear part contains an internal support 56, which is also hollow and flared, thereby forming an internal space for the built-in oscillating power transmission assembly. The oscillating brush head assembly 52 is disposed at the front end of the brush handle housing 51. The rear end of the oscillating power transmission assembly is connected to the output shaft 245 of the oscillating motor 20 of the electric toothbrush, and the front end is connected to the oscillating brush head assembly 52, thereby transmitting the output power of the oscillating motor 20 to the oscillating brush head assembly 52.

[0195] The oscillating brush head assembly 52 includes a brush head 521, a rotating shaft 522, a bristle tuft seat 523, and oscillating bristles 524. The rear end of the brush head 521 extends into the front end of the brush head housing 51 and is rotatably fixed to the internal support 56 via the rotating shaft 522. The front end of the brush head 521 is fixed with a bristle tuft seat 523, and the bristle tuft seat 523 is fitted with multiple oscillating bristles 524 for cleaning.

[0196] The brush head 521 is provided with a shaft hole through which the rotating shaft 522 rotates. Both ends of the rotating shaft 522 extend into the internal bracket 56, thereby forming the swing fulcrum of the brush head.

[0197] The oscillating vibration power transmission assembly includes a oscillating shaft 53 and a coupling assembly. The front end of the oscillating shaft 53 is embedded in a recessed hole at the rear end of the brush head 521, and the rear end is connected to the coupling assembly, which serves as the output power coupling point. The power drives the coupling point to oscillate in an oscillating manner. The coupling assembly includes a coupling block 54 and a connecting pipe 55. The oscillating shaft 53 extends into the front end of the connecting pipe 55, and the rear end of the connecting pipe 55 is connected to the output shaft 245 of the oscillating vibration motor 20 of the electric toothbrush through the coupling block 54.

[0198] The coupling block 54 is made of an elastic material and serves as the passive end, while the connecting pipe 55 is made of a rigid material and serves as the active end.

[0199] The motion of the oscillating motor is shown in Figures 23A, 23B, 24A, and 24B, and its oscillation process is the same as before.

[0200] It is obvious that this method matches the motion trajectory of the motor output and the coupling point of the toothbrush shaft, and the parallel line of this reciprocating transformation is perpendicular to the axis of the toothbrush body.

[0201] The concave hole at the rear end of the brush head 521 is perpendicular to the swing shaft 53.

[0202] When the output shaft swings, the power is coupled through the coupling assembly, and the brush head 521 swings around the rotating shaft at the top of the inner bracket of the brush head. The swing of the shaft is linked to the swing of the brush head to realize the brushing process.

[0203] The swing trajectory of the output shaft can be arc-shaped or an axis perpendicular to the main body axis. Both swing modes can effectively drive the swing shaft of the brush rod.

[0204] Preferably, the coupling assembly adopts an elastic coupling structure, which consists of a trumpet-shaped connecting pipe 55 and a coupling block 54 inside the connecting pipe 55. The coupling block 54 is an elastic body with a through hole, and the output shaft of the oscillating motor is fitted into the elastic body. This special structural design solves two problems:

[0205] 1. The through-hole of the elastomer mates with the output shaft of the oscillating motor. If both the hole and shaft are rigidly coupled, wear will inevitably occur under high-frequency oscillation. The worn hole and shaft will then experience high-frequency reciprocating impacts, generating severe noise. By adopting an elastic coupling design, the reciprocating impacts generated after wear are absorbed by the elastomer itself and dissipated as heat, effectively solving the noise problem after wear.

[0206] 2. The dynamic coupling point features an elastic design. Due to the material properties of the elastomer, an interference fit between the shaft and the hole is permissible. If motion interference occurs during rotation, the elastomer can mitigate the impact of this interference through its deformable properties. A well-designed interference fit between the shaft and the hole effectively extends the brush rod's lifespan.

[0207] Therefore, the oscillating brush head assembly can be designed into shapes such as ellipse, circle, rectangle, triangle, etc., according to actual usage requirements.

[0208] The brush handle housing 51 encloses the moving brush head and swing shaft, effectively reducing the discomfort caused to the user by direct contact between the brush head and the human mouth and high-speed friction and impact. It also effectively reduces the power loss caused by direct contact between the brush head and the human body, and improves the swing output efficiency.

[0209] The axis of the rotating shaft 522 is perpendicular to the swing direction of the output shaft.

[0210] The connecting pipe 55 is a trumpet-shaped sleeve.

[0211] The coupling block 54 is a hollow sleeve with a concave annular protrusion in its middle part.

[0212] It may also be equipped with a compensation pad 57 to compensate for the swinging motion.

[0213] The front end of the brush rod housing 51 extends into a brush head protective cap to accommodate the brush head. The brush head protective cap and the moving brush head 521 maintain a distance G (as shown in Figure 28). This distance G ensures that the oscillating brush head does not rub against the edge of the cap at the front end of the brush rod housing, and ensures that all high-speed moving parts work within the housing. This solves the discomfort caused by the direct contact between the inner wall of the oral cavity and the high-frequency oscillating brush head during the use of conventional oscillating brush heads.

[0214] Preferably, the brush head protective cap is a cap-shaped tongue that partially encloses the brush head, which can better enclose the brush head and provide space for its movement.

[0215] Figures 29A, 29B, and 29C show schematic diagrams of the operation of the oscillating electric toothbrush rod with a protective device in this invention. When the output shaft oscillates, the power is coupled through the coupling assembly, and the brush head 521 oscillates with the rotation axis at the top of the inner bracket of the brush rod as the fulcrum. The oscillation of the swing shaft is linked to the oscillation of the brush head to realize the brushing process.

[0216] Therefore, it is evident that conventional high-frequency oscillating toothbrush heads cause discomfort during use because the back of the oscillating brush head directly rubs against the user's oral cavity wall through impact contact. The oscillating brush handle disclosed in this invention features a cap-like brim at the front of the housing, surrounding the back of the brush head. The size of this brim is designed not to affect the maximum oscillation stroke of the brush head. This brim effectively prevents direct contact between the user's oral cavity wall and the high-frequency oscillating brush head, solving the problem of excessive stimulation from the brush head's back. The brim also effectively reduces pressure from the oral cavity wall on the moving brush head, resulting in a more stable oscillation amplitude and minimizing power loss.

[0217] In summary, the technical content of this invention combines the advantages of both, and achieves a high-frequency reciprocating rotating brush head as a technical feature, overcoming the common defects of high-frequency rotating toothbrushes such as high noise and short lifespan, and effectively increasing the rotation or oscillation frequency from the conventional limit of 133Hz to 350Hz.

[0218] The present invention employs flexible compensation technology to solve the problems of noise and lifespan of the brush rod under high-frequency operation.

[0219] The electric toothbrush of this invention effectively combines two modes, adapting to both high-frequency rotating brush heads and high-frequency oscillating brushes. It achieves power drive characterized by 140-350Hz high-frequency vibration, meeting diverse and efficient cleaning needs of users. Furthermore, it features low noise and a simple structure in both oscillating and rotating torque operation, offering good economic efficiency.

[0220] It is obvious that the above description and account are merely illustrative and not intended to limit the disclosure, application, or use of this invention. Although embodiments have been described and illustrated in the accompanying drawings, the invention is not limited to the specific examples exemplified by the drawings and described in the embodiments as currently considered the best mode for carrying out the teachings of the invention. The scope of the invention will include any embodiments falling within the foregoing description and the appended claims.

Claims

1. A high-frequency power multi-mode electric toothbrush, comprising a body shell, a oscillating motor, a rotating brush bar, and an oscillating brush bar, wherein the body shell is hollow to form an internal space, a control circuit board is disposed within the body shell, and a plurality of function buttons connected to the control circuit board are provided on the side wall, characterized in that: The built-in space of the main body housing is equipped with a oscillating motor. The output shaft of the oscillating motor extends from the front end of the main body housing to provide power output. The oscillating motor includes a motor bracket, an electromagnetic coil, a vibrating arm assembly, a front cover, and a magnet. The front end of the motor bracket is equipped with a front cover, and the rear end is equipped with a magnet. A shock-absorbing block is also provided on the rear side of the magnet. An inner cavity is formed inside the motor bracket to accommodate the vibrating arm assembly. The rear outer edge of the inner cavity is covered with an electromagnetic coil. The vibrating arm assembly includes a swing arm, a rotating shaft, bearings, and a connecting frame. The rear part of the swing arm is located in an electromagnetic coil at the rear of the inner cavity. The front part of the swing arm forms a disc portion with a shaft hole for the rotating shaft to pass through. The two ends of the rotating shaft are rotatably supported by a motor bracket via bearings. The rear end of the connecting frame covers the front part of the swing arm and forms a cylindrical structure that accommodates the disc portion of the swing arm. The front end of the connecting frame is connected to the rear end of the output shaft to transmit the vibration generated by the vibrating arm assembly to the output shaft for output.

2. The high-frequency power multi-mode electric toothbrush as described in claim 1, characterized in that: The swing arm, rotating shaft, and output shaft are integrated into a vibrating arm assembly by forming a connecting frame through secondary plastic injection molding. The swing arm is a straight iron swing arm, and the rotation axis of the rotating shaft is perpendicular to the swing direction of the swing arm.

3. The high-frequency power multi-mode electric toothbrush as described in claim 1, characterized in that: The two ends of the rotating shaft are provided with shoulders that cooperate with the bearings, and the rear end of the output shaft is provided with at least one concave ring, so that the output shaft and the connecting frame are stably integrally formed after secondary injection molding.

4. The high-frequency power multi-mode electric toothbrush as described in claim 1, characterized in that: The swing arm is made of stacked silicon steel sheets with high frequency and low eddy current loss.

5. The high-frequency power multi-mode electric toothbrush as described in claim 1, characterized in that: The rotating brush rod includes a brush rod housing, an inner support, a rotating brush head assembly, and a power transmission assembly. The inner support is disposed inside the brush rod housing to form an internal space for the built-in power transmission assembly. The rotating brush head assembly is disposed at the front end of the brush rod housing. The rear end of the rotating power transmission assembly is connected to the output shaft of the oscillating motor, and the front end is connected to the rotating brush head assembly, thereby transmitting the output power of the oscillating motor to the rotating brush head assembly.

6. The high-frequency power multi-mode electric toothbrush as described in claim 5, characterized in that: The rotating brush head assembly includes a brush head base and rotating bristles. The brush head base is rotatably disposed inside the front end of the brush handle housing. One end of the brush head base is fitted with multiple rotating bristles for cleaning, and the other end is provided with a base connected to the rotating power transmission assembly.

7. The high-frequency power multi-mode electric toothbrush as described in claim 6, characterized in that: The rotary power transmission assembly includes a rocker arm, an elastic fulcrum, an elastic coupler, a drive head, a compensating spring, and a connecting sleeve. The front end of the rocker arm is provided with a drive head that extends into the base of the brush head holder. The base of the brush head holder forms a passive component that matches the shape of the drive head. A compensating spring is sleeved between the drive head and the elastic fulcrum on the rocker arm. The rear end of the rocker arm extends into the front end of the connecting sleeve. The rear end of the connecting sleeve is connected to the output shaft through the elastic coupler.

8. The high-frequency power multi-mode electric toothbrush as described in claim 1, characterized in that: The oscillating brush rod includes a brush rod housing, an internal support, an oscillating brush head assembly, and an oscillating power transmission assembly. The internal support is disposed inside the brush rod housing to form an internal space for the built-in oscillating power transmission assembly. The oscillating brush head assembly is disposed at the front end of the brush rod housing. The rear end of the oscillating power transmission assembly is connected to the output shaft of the oscillating motor, and the front end is connected to the oscillating brush head assembly, thereby transmitting the output power of the oscillating motor to the oscillating brush head assembly.

9. The high-frequency power multi-mode electric toothbrush as described in claim 8, characterized in that: The oscillating brush head assembly includes a brush head, a rotating shaft, a bristle tuft seat, and oscillating brush bristles. The rear end of the brush head extends into the front end of the brush head housing and is rotatably fixed to the internal support via the rotating shaft. The front end of the brush head is fixed with a bristle tuft seat, and the bristle tuft seat is fitted with multiple oscillating brush bristles for cleaning.

10. The high-frequency power multi-mode electric toothbrush as described in claim 8, characterized in that: The pendulum vibration transmission assembly includes a pendulum shaft, a coupling block, and a connecting tube. The front end of the pendulum shaft is embedded in the recessed hole at the rear end of the brush head, and the rear end extends into the front end of the connecting tube. The rear end of the connecting tube is connected to the output shaft through the coupling block.

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