Bidirectional motion motor and electric toothbrush

Abstract

The utility model discloses a bidirectional motion motor and an electric toothbrush, the bidirectional motion motor comprises a casing, a rotor assembly, a stator assembly and a bearing assembly, the rotor assembly is arranged in the casing and is provided with a rotating shaft; the stator assembly is arranged in the machine shell and used for driving the rotor assembly to swing in a reciprocating mode in the circumferential direction of the rotating shaft and driving the rotor assembly to stretch out and draw back in the axial direction of the rotating shaft. The bearing assembly comprises an outer ring, a sliding ring and a plurality of balls, and the outer ring is fixedly connected to the machine shell. The sliding ring is movably arranged between the outer ring and the rotating shaft; the balls are movably connected to the sliding ring. Wherein the rotating shaft is in rolling fit with the outer ring through the balls, so that the rotating shaft can perform circumferential reciprocating swing and axial stretching relative to the outer ring; and when the rotating shaft performs circumferential reciprocating swing and axial stretching, the outer ring is kept relatively fixed with the shell in the axial direction and the circumferential direction.

Description

Technical Field

[0001] This application relates to the technical field of electric toothbrushes, and particularly to a bidirectional motion motor and an electric toothbrush. Background Art

[0002] An electric toothbrush is a tool that achieves the effect of cleaning teeth by the rapid rotation or vibration of a motor core, causing the brush head to generate high-frequency vibration.

[0003] To adapt to the brushing habits of different users and meet various usage scenarios, it is often required that the brush head can vibrate in multiple directions, such as the brush head can achieve left and right swinging and telescopic vibration.

[0004] In related technologies, to reduce the friction between moving parts and ensure the smoothness and accuracy of mechanical motion, bearings are often provided on the rotating shaft. The bearings can significantly reduce the friction force during mechanical motion and reduce energy loss. During the movement of the bearings, the position of the outer ring is inaccurate or the motion control is improper, resulting in the rotation center or motion axis of the rotor not coinciding with the center of the bearing, and the outer ring may have unexpected contact or friction with other components. Utility Model Content

[0005] The embodiments of this application provide a bidirectional motion motor and an electric toothbrush, which can reduce unexpected contact and friction between the outer ring and other components.

[0006] In a first aspect, the embodiments of this application provide a bidirectional motion motor, including:

[0007] A housing;

[0008] A rotor assembly, disposed within the housing and having a rotating shaft;

[0009] A stator assembly, disposed within the housing, for driving the rotor assembly to reciprocally swing along the circumference of the rotating shaft, and for driving the rotor assembly to telescopically extend and retract along the axis of the rotating shaft; and

[0010] A bearing assembly, the bearing assembly including:

[0011] An outer ring, fixedly connected to the housing;

[0012] A slip ring, movably disposed between the outer ring and the rotating shaft; and

[0013] A plurality of balls, movably connected to the slip ring;

[0014] Wherein, the rotating shaft is in rolling fit with the outer ring through the ball bearings, so that the rotating shaft can perform the circumferential reciprocating swing and the axial telescopic movement relative to the outer ring; when the rotating shaft performs the circumferential reciprocating swing and the axial telescopic movement, the outer ring remains relatively fixed with the housing in the axial direction and the circumferential direction.

[0015] By adopting the above technical solution, by arranging a plurality of ball bearings to replace sliding friction with rolling friction, the frictional resistance of the bidirectional motion motor can be reduced, energy loss can be reduced, the operating efficiency of the bidirectional motion motor can be improved, and the rolling motion of the ball bearings helps to reduce vibration and noise, improving the motion smoothness of the bidirectional motion motor. Arranging a plurality of ball bearings can reduce the load on a single ball bearing and avoid local overload. The outer ring remains relatively fixed with the housing in the axial direction and the circumferential direction, and the outer ring can provide a stable support point for the rotor assembly, so that the axial center position of the rotor assembly remains unchanged during the movement process, avoiding mechanical failures caused by axial center offset. Moreover, the stability of the axial center of the rotor assembly reduces the possibility of friction between the rotating shaft and other components inside the outer ring or the housing. Friction occurs when the axial center is offset and the rotating shaft contacts the static components, and the relative fixation of the outer ring and the housing can reduce the risk of friction, and thus no impact sound or vibration noise caused by friction will be generated. The unbalanced force caused by axial center offset is reduced, improving the motion accuracy and service life of the motor.

[0016] Optionally, the slip ring is provided with a plurality of through holes, and the plurality of through holes are arranged at intervals;

[0017] Each ball bearing is received and limited in a through hole, and is in rolling contact with the rotating shaft and the outer ring respectively.

[0018] By adopting the above technical solution, the ball bearings can rotate freely in the through holes but will not fall out of the slip ring, enabling the slip ring to achieve both rolling rotational motion and rolling linear motion.

[0019] Optionally, the ratio of the diameter of the ball bearing to the wall thickness of the slip ring is k, and 1.1 ≤ k ≤ 2.

[0020] By adopting the above technical solution, the coordination between the ball bearings and the slip ring can be ensured, the rolling friction between the ball bearings and the slip ring can be optimized, low-energy consumption and high-efficiency motion can be achieved, and further the service life of the bearing assembly can be extended.

[0021] Optionally, the plurality of ball bearings are symmetrically arranged along the axial central plane of the slip ring.

[0022] By adopting the above technical solution, that is, the slip ring has at least two support points between the rotating shaft and the outer ring, enabling the slip ring to operate smoothly and not to be easily tilted.

[0023] Optionally, the plurality of balls are arranged in four rows along the circumference of the slip ring, and the balls in the four rows are evenly spaced along the circumference of the slip ring;

[0024] The number of the balls in each row is two, and the two balls in the same row are symmetrically arranged along the radial midplane of the slip ring.

[0025] By adopting the above technical solution, this distribution method ensures that no matter where the force point is located, at least one ball can bear the force. In most cases, the two balls in each circle jointly bear the force from all directions. This synergy improves the support efficiency of the bearing assembly and ensures the stability of the shaft when it is subjected to force in multiple directions.

[0026] Optionally, the slip ring has an inner raceway and an outer raceway, the inner raceway is arranged on the inner wall surface of the slip ring, and the outer raceway is arranged on the outer wall surface of the slip ring;

[0027] One of the inner raceway and the outer raceway is arranged to extend in the axial direction of the rotating shaft, and the other of the inner raceway and the outer raceway is arranged to extend in the circumferential direction of the slip ring;

[0028] The balls include inner balls and outer balls. The inner balls are rollably mounted between the inner raceway and the rotating shaft, and the outer balls are rollably mounted between the outer raceway and the outer ring.

[0029] By adopting the above technical scheme, the inner raceway and the outer raceway provide precise rolling paths for the inner ball and the outer ball respectively, clarify the movement paths of the inner ball and the outer ball, and at the same time restrict the inner ball and the outer ball to move only in the inner raceway and the outer raceway respectively, and cannot deviate from the corresponding track, thereby increasing the flexibility of the bearing assembly, supporting the multi-directional movement of the rotating shaft, and providing the rotating shaft with freedom of movement in two directions, including axial movement and circumferential swing.

[0030] Optionally, the inner raceway is extended along the axial direction of the rotating shaft, and the length of the inner raceway is greater than or equal to half of the total axial telescopic stroke of the mover assembly along the rotating shaft.

[0031] By adopting the above technical solution, it is ensured that even when the mover assembly is extended and retracted to the extreme position in the axial direction, the inner ball can still roll stably in the inner raceway, providing reliable support and precise guidance.

[0032] Optionally, the inner raceway is arranged to extend along the axial direction of the rotating shaft, the number of the inner raceways is four, and the four inner raceways are evenly spaced along the circumference of the slip ring.

[0033] By adopting the above technical solution, when the rotating shaft is subjected to an axial force, the four longitudinal raceways can share this force. In most cases, two adjacent longitudinal raceways will jointly bear the main load. This load sharing mechanism reduces the stress on a single raceway, thereby reducing wear.

[0034] Optionally, the outer raceway is arranged circumferentially around the slip ring, and the number of the outer raceways is two. The two outer raceways are arranged at intervals along the axial direction of the rotating shaft.

[0035] By adopting the above technical solution, it helps to distribute the load more evenly, reduce the local wear of the outer balls and the outer raceway, and extend the service life of the bearing assembly.

[0036] Optionally, the bearing assembly further includes:

[0037] An inner cage, located between the rotating shaft and the inner raceway. The inner cage is provided with a first bearing hole for accommodating the inner ball, and the inner cage is used to limit the position of the inner ball.

[0038] By adopting the above technical solution, it ensures that the inner ball maintains the correct position during the rolling process, avoiding the deviation or misalignment of the inner ball. The inner cage can limit the vibration of the inner ball, reducing the noise or vibration caused by the collision or improper position of the inner ball. The inner cage can also provide additional support and guidance for the inner ball, enhancing the reliability of the bearing assembly during long-term use.

[0039] Optionally, the inner raceway extends along the axial direction of the rotating shaft, the inner cage is a longitudinal cage, and the longitudinal cage is provided with two first bearing holes. The two first bearing holes are arranged at intervals along the axial direction of the rotating shaft and are symmetrically arranged with respect to the central axis of the longitudinal cage.

[0040] By adopting the above technical solution, the distance between the two inner balls can be maintained, making the operation of the bearing assembly more stable.

[0041] Optionally, the slip ring is provided with a first jack, and the bearing assembly further includes:

[0042] A stop member, which is in interference fit with the inner wall of the first jack, and the stop member is used to limit the longitudinal cage from disengaging from the inner raceway.

[0043] By adopting the above technical solution, the stop member is provided to prevent the longitudinal cage and the inner ball from falling off from the axial ends of the slip ring.

[0044] Optionally, the bearing assembly further includes:

[0045] An outer cage, located between the outer ring and the outer raceway, is provided with second bearing holes for accommodating the outer balls, and the outer cage is used to position the outer balls.

[0046] By adopting the above technical solution, it is ensured that the outer balls run stably in the outer raceway, preventing the outer balls from being misaligned or derailed, and the outer cage can keep the outer balls running in the correct position, improving the smoothness of the bearing assembly during operation.

[0047] Optionally, the outer raceway is arranged circumferentially around the slip ring, the outer cage is an annular cage, and a plurality of the second bearing holes are provided on the annular cage, and the plurality of second bearing holes are evenly spaced along the circumferential direction of the annular cage.

[0048] By adopting the above technical solution, the spacing between the plurality of outer balls is maintained.

[0049] Optionally, four second bearing holes are provided on the annular cage.

[0050] By adopting the above technical solution, that is, the adjacent two outer balls are arranged at an interval of 90°, the load from different directions can be more evenly borne, and the stress concentration of a single outer ball is reduced.

[0051] Optionally, the slip ring has an inner arc-shaped raceway and an outer arc-shaped raceway, the inner arc-shaped raceway is arranged on the inner wall surface of the slip ring, and the outer arc-shaped raceway is arranged on the outer wall surface of the slip ring;

[0052] The balls include inner balls and outer balls, the inner balls are rollably installed between the inner arc-shaped raceway and the rotating shaft, and the outer balls are rollably installed between the outer arc-shaped raceway and the outer ring.

[0053] By adopting the above technical solution, the inner arc-shaped raceway and the outer arc-shaped raceway provide a smooth movement track, making the inner balls and the outer balls run more smoothly during the rolling process.

[0054] Optionally, the bidirectional movement motor further includes:

[0055] A snap ring, which is in interference fit with the inner wall surface of the outer ring and sleeved on the circumferential side of the rotating shaft to limit the axial movement stroke of the slip ring.

[0056] By adopting the above technical solution, the shedding of the slip ring is effectively prevented, and by controlling the movement range of the slip ring, the unnecessary contact and wear between the slip ring and other components are reduced.

[0057] Optionally, the snap ring is arranged at a radial interval from the rotating shaft along the radial direction of the rotating shaft.

[0058] By adopting the above technical solution, the direct contact between the rotating shaft during axial and circumferential movements and the retaining ring is reduced.

[0059] Optionally, the retaining ring is provided with a second jack, and the rotating shaft is inserted through the second jack;

[0060] Wherein, the diameter of the second jack is smaller than the diameter of the slip ring.

[0061] By adopting the above technical solution, when the slip ring is sleeved on the rotating shaft and located between the two retaining rings, it will not be easily slipped out of the second jack of the retaining ring, thus effectively preventing the slip ring from falling off.

[0062] Optionally, there are two retaining rings, and the two retaining rings are arranged at intervals along the axial direction of the outer ring, and the slip ring is arranged between the two retaining rings.

[0063] By adopting the above technical solution, the movement position of the slip ring on the rotating shaft is ensured, and the axial crosstalk of the slip ring is avoided.

[0064] Optionally, the distance between the two opposite wall surfaces of the two retaining rings is D1, the length of the slip ring is L1, and the total telescopic stroke of the mover assembly along the axial direction of the rotating shaft is X1, D1 - L1 ≥ X1.

[0065] By adopting the above technical solution, the slip ring will not frequently impact the retaining ring during movement, reducing the wear rate of the retaining ring and the slip ring caused by the impact.

[0066] Optionally, the distance between the two opposite wall surfaces of the two retaining rings is D1, and the total telescopic stroke of the mover assembly along the axial direction of the rotating shaft is X1, D1 ≥ X1 / 2.

[0067] By adopting the above technical solution, it is ensured that the slip ring can roll normally during the telescopic movement of the rotating shaft without being blocked due to insufficient space.

[0068] Optionally, the bearing assembly further includes:

[0069] An inner ring, sleeved on the rotating shaft and fixedly connected to the rotating shaft;

[0070] Wherein, the ball rolls against the outer wall of the inner ring and the inner wall of the outer ring.

[0071] By adopting the above technical solution, it plays a role in protecting the rotating shaft, can improve the anti-impact performance of the part of the rotating shaft sleeved with the inner ring, and the inner ring has a smooth surface, which can further reduce the friction resistance of the ball, thereby improving the operating efficiency of the bearing assembly.

[0072] Optionally, along the axial direction of the rotating shaft, the length of the inner ring is greater than or equal to the length of the outer ring.

[0073] By adopting the above technical solution, the possibility of collision between the two ends of the inner ring and the retaining ring is reduced, thereby avoiding possible movement hindrance.

[0074] Optionally, the difference between the length of the inner ring and the length of the outer ring is greater than or equal to the amplitude of the rotating shaft.

[0075] By adopting the above technical solution, interference between the inner ring and the retaining ring is avoided when the rotating shaft moves back and forth axially.

[0076] Optionally, the bidirectional movement motor further includes:

[0077] A retaining ring, the outer peripheral side of the retaining ring is clamped in the outer ring and sleeved on the circumferential side of the rotating shaft to limit the axial movement stroke of the slip ring;

[0078] Wherein, the retaining ring is arranged between the outer ring and the inner ring along the radial direction of the rotating shaft, and the retaining ring and the inner ring are arranged at a radial interval along the rotating shaft.

[0079] By adopting the above technical solution, friction between the retaining ring and the inner ring is prevented when the rotating shaft moves axially and swings circumferentially.

[0080] In a second aspect, an embodiment of the present application further provides an electric toothbrush, including:

[0081] The bidirectional movement motor as described in any one of the above;

[0082] A handle housing, the bidirectional movement motor is arranged in the handle housing, one end of the rotating shaft is arranged in the handle housing, and the other end passes through the handle housing and is located outside the handle housing; and

[0083] A brush head, the brush head is connected to the end of the rotating shaft located outside the handle housing.

[0084] By adopting the above technical solution, the bidirectional movement motor can realize the axial movement and circumferential swing of the brush head, and this compound movement mode can provide a more comprehensive tooth cleaning effect. Description of the Drawings

[0085] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0086] Figure 1 Schematic diagram of the structure of a bidirectional motion motor in an embodiment of the present application;

[0087] Figure 2 is Figure 1 a schematic diagram of a disassembled structure of the bidirectional motion motor in

[0088] Figure 3 is Figure 1 another schematic diagram of a disassembled structure of the bidirectional motion motor in

[0089] Figure 4 is Figure 1 yet another schematic diagram of a disassembled structure of the bidirectional motion motor in

[0090] Figure 5 is Figure 1 the front view of the bidirectional motion motor in

[0091] Figure 6 is Figure 5 the cross-sectional view along the AA section line in

[0092] Figure 7 is Figure 6 the partial enlarged view at B in

[0093] Figure 8 Schematic diagram of a disassembled structure of a bearing assembly in an embodiment of the present application;

[0094] Figure 9 is Figure 8 another schematic diagram of a disassembled structure of the bearing assembly in

[0095] Figure 10 Schematic diagram of the structure of a bearing assembly in another embodiment of the present application;

[0096] Figure 11 is Figure 10 the cross-sectional view along the CC section line in

[0097] Figure 12 is Figure 10 a schematic diagram of a disassembled structure of the bearing assembly in

[0098] Figure 13 is Figure 10 another schematic diagram of a disassembled structure of the bearing assembly in

[0099] Figure 14 is Figure 10 a partial schematic diagram of the bearing assembly in

[0100] Figure 15 is Figure 14 a partial disassembled schematic diagram of the bearing assembly in

[0101] Description of the reference numerals in the drawings:

[0102] 100, bidirectional motion motor; 10, housing; 20, rotor assembly; 21, rotating shaft; 22, fixed seat; 23, permanent magnet; 30, stator assembly; 31, stator core; 311, stator teeth; 32, coil winding; 40, bearing assembly; 41, outer ring; 42, slip ring; 42a, through hole; 42b, first jack; 421, inner raceway; 422, outer raceway; 43, ball; 431, inner ball; 432, outer ball; 44, inner cage; 44a, first bearing hole; 45, outer cage; 45a, second bearing hole; 46, stopper; 47, inner ring; 50, retaining ring; 50a, second jack.

[0103] The realization of the purpose of this application, its functional features and advantages will be further described in conjunction with the embodiments with reference to the drawings. Detailed implementation manners

[0104] In order to make the purpose, technical solutions and advantages of this application clearer, the following further details this application in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application.

[0105] In a first aspect, please refer to Figure 1 and Figure 2 , an embodiment of this application relates to a bidirectional motion motor 100, which includes a housing 10, a rotor assembly 20, a stator assembly 30 and a bearing assembly 40.

[0106] Among them, the housing 10 has a receiving cavity. The housing 10 is used to protect the components in the receiving cavity and provide stable support for the components in the receiving cavity, protecting the internal components from the outside world and ensuring the overall stability and durability of the bidirectional motion motor 100. The overall shape of the housing 10 can be cylindrical. The rotor assembly 20 and the stator assembly 30 are both arranged in the receiving cavity of the housing 10. The rotor assembly 20 has a rotating shaft 21. The stator assembly 30 can precisely control the movement of the rotor assembly 20 to ensure the smoothness and accuracy of the movement. The stator assembly 30 is used to drive the rotor assembly 20 to swing back and forth along the circumference of the rotating shaft 21 and to drive the rotor assembly 20 to expand and contract along the axis of the rotating shaft 21. The bearing assembly 40 is sleeved on the rotating shaft 21, which can not only increase the radial support of the rotating shaft 21, but also reduce the friction between the rotating shaft 21 and the housing 10 or the stator assembly 30, ensuring the free movement of the rotating shaft 21 in the axial and circumferential directions.

[0107] As Figure 2As shown, exemplarily, there are two sets of bearing assemblies 40. The two sets of bearing assemblies 40 are spaced apart axially on the rotating shaft 21 and are respectively located at opposite ends of the rotor assembly. The two sets of bearing assemblies 40 can provide more uniform radial support. The two-end support can better disperse the load on the rotating shaft 21, reduce the load pressure on a single bearing assembly 40, and reduce the bending or twisting of the rotating shaft 21, thereby improving the stability of the overall structure.

[0108] Please refer to Figure 3 , the mover assembly 20 includes a fixed seat 22 and a plurality of permanent magnets 23. The configuration of the plurality of permanent magnets 23 can enhance the magnetic force effect of the rotor assembly. The fixed seat 22 is sleeved on the rotating shaft 21 to achieve a fixed connection with the rotating shaft 21. A plurality of the above-mentioned permanent magnets 23 are evenly spaced on the outer peripheral wall of the fixed seat 22, which helps to generate a uniformly distributed magnetic field. The permanent magnets 23 are firmly connected to the fixed seat 22, reducing the vibration and displacement of the magnets during operation and improving the structural stability of the entire rotor assembly.

[0109] Please continue to refer to Figure 3 , the stator assembly 30 includes a stator core 31 and a coil winding 32. The stator core 31 is disposed around the mover assembly 20. The stator core 31 includes a plurality of stator teeth 311 evenly distributed on the inner wall facing the mover assembly 20. The coil winding 32 is wound around the stator teeth 311. When the coil winding 32 is energized, it can drive the mover assembly 20 to drive the rotating shaft 21 to perform axial telescoping and circumferential swinging.

[0110] The stator assembly 30 includes a first stator mechanism and a second stator mechanism. The first stator mechanism is used to drive the mover assembly 20 to reciprocate circumferentially along the rotating shaft 21, and the second stator mechanism is used to drive the mover assembly 20 to axially telescope along the rotating shaft 21. The first stator mechanism and the second stator mechanism are respectively arranged corresponding to the mover assembly 20, so as to enable the rotating shaft 21 to swing circumferentially and reciprocate axially. Compared with two independent drive mechanisms formed by using two mover assemblies 20 and two rotor assemblies correspondingly, it can realize the miniaturization of the bidirectional motion motor 100, reduce the volume and weight of the bidirectional motion motor 100. Furthermore, when the bidirectional motion motor 100 is applied to an electric toothbrush, it can realize the lightweight of the electric toothbrush, making the electric toothbrush more convenient to carry and facilitating users to use when traveling or going out.

[0111] Understandably, when the bidirectional motion motor 100 is applied to an electric toothbrush, the brush head of the electric toothbrush is connected to the rotating shaft 21. The rotating shaft 21 can perform linear reciprocating motion and circumferential reciprocating swing under the drive of the mover assembly 20. This compound motion mode enables the brush head to have more flexible motion ability.

[0112] Exemplarily, when the electric toothbrush is turned on, the rotating shaft 21 can perform a linear reciprocating motion driven by the mover assembly 20, which helps the brush head move back and forth on the tooth surface to remove dental plaque and food residues. At the same time, the rotating shaft 21 can also achieve a circumferential reciprocating swing, which enables the brush head to perform multi-angle and multi-directional cleaning actions on the teeth at a fixed position. This cleaning method simulates various brushing techniques during manual brushing, can clean the tooth gaps and tooth surfaces more deeply, and achieve a more comprehensive oral cleaning effect.

[0113] Specifically, as Figure 4 shown, the bearing assembly 40 includes an outer ring 41, a slip ring 42, and a plurality of balls 43.

[0114] Among them, along the axial direction, the radial cross-section of the outer ring 41 is annular and is fixedly connected to the inner wall of the housing 10. The outer ring 41 is a rigid outer ring 41 or a hard outer ring 41. The outer ring 41 provides a stable support base for the bearing assembly 40, preventing the unexpected movement or vibration of the outer ring 41, thereby reducing the friction and wear caused by the inaccurate position of the outer ring 41. The slip ring 42 is also a rigid slip ring 42 or a hard slip ring 42. The slip ring 42 is movably arranged between the outer ring 41 and the rotating shaft 21. The balls 43 are rigid balls 43 or hard balls 43. The plurality of balls 43 are movably connected to the slip ring 42. The balls 43 are in rolling contact with the inner surface of the outer ring 41 and the outer surface of the rotating shaft 21, that is, the balls 43 are rigidly matched with the rotating shaft 21, and the slip ring 42 can provide a guiding function for the plurality of balls 43.

[0115] In the related art, a sliding bearing is mostly used to reduce the frictional resistance during the movement of the rotating shaft 21. However, the sliding bearing must overcome sliding friction both during circumferential rotation and axial movement, and the resistance of sliding friction is relatively large. In this embodiment, by providing a plurality of balls 43 to replace sliding friction with rolling friction, the frictional resistance of the bidirectional movement motor can be reduced, energy loss can be reduced, the operating efficiency of the bidirectional movement motor 100 can be improved, and the rolling movement of the balls 43 helps to reduce vibration and noise and improve the movement stability of the bidirectional movement motor 100. Providing a plurality of balls 43 can reduce the load on a single ball 43 and avoid local overload.

[0116] Among them, as Figures 5 - 7As shown, the rotating shaft 21 is in rolling fit with the outer ring 41 through the balls 43, enabling the rotating shaft 21 to perform reciprocating circumferential swinging and axial telescoping relative to the outer ring 41, providing a multi-directional motion mode. When the rotating shaft 21 performs reciprocating circumferential swinging and axial telescoping, the outer ring 41 remains relatively fixed with respect to the housing 10 axially and circumferentially. The outer ring 41 can provide a stable support point for the mover assembly 20, keeping the axial position of the mover assembly 20 unchanged during movement and avoiding mechanical failures caused by axial offset. Moreover, the stability of the axis of the mover assembly 20 reduces the possibility of friction between the rotating shaft 21 and other components within the outer ring 41 or the housing 10. Rubbing occurs when the axial offset causes the rotating shaft 21 to contact static components, and the relative fixation of the outer ring 41 and the housing 10 can reduce the risk of rubbing, thus preventing the impact sound or vibration noise caused by rubbing. The unbalanced force caused by axial offset is reduced, improving the motion accuracy and service life of the motor.

[0117] As Figure 8 shown, in some embodiments, multiple balls 43 are symmetrically arranged along the axial mid-plane of the slip ring 42. The axially symmetrically arranged balls 43 can provide symmetric supporting forces, that is, the slip ring 42 has at least two points of support between the rotating shaft 21 and the outer ring 41, enabling the slip ring 42 to operate smoothly and not easily tilt. The axially symmetric layout of the balls 43 can also better adapt to the multi-directional movement of the rotating shaft 21, such as axial telescoping and circumferential swinging.

[0118] In some embodiments, multiple balls 43 are arranged in four columns along the circumference of the slip ring 42, and the number of balls 43 in each column is two, that is, multiple balls 43 are arranged in two circles along the circumference of the slip ring 42, and the number of balls 43 in each circle is four. Two circles have better stability compared to only setting one circle, and the force can be evenly distributed to the two balls 43 in each column, thereby increasing the service life of the bearing assembly 40. Compared with setting three or more circles of balls 43, setting two circles can not only meet the performance requirements but also avoid the cost increase caused by using too many balls 43.

[0119] Please continue to refer to Figure 8 , the four balls 43 in each circle are evenly spaced, capable of forming supports in the positive and negative directions of the horizontal and vertical axes, ensuring that the load can be effectively dispersed in all directions. This distribution method ensures that at least one ball 43 can bear the force regardless of where the force application point is located. In most cases, two balls 43 in each circle jointly bear the forces from all directions. This synergistic effect improves the support efficiency of the bearing assembly 40 and ensures the stability of the rotating shaft 21 under multi-directional forces.

[0120] Exemplarily, when the bearing assembly 40 is subjected to a vertical downward force, the balls 43 that are most directly subjected to the force are those located in the force direction (ie, below). In each circle, the two balls 43 near the bottom will first contact and provide support force.

[0121] Specifically, two balls 43 in the same row are symmetrically arranged along the radial midplane of the slip ring 42. The radially symmetrical layout increases the stability of the slip ring 42 during movement, making it less likely for the slip ring 42 to tilt or deflect when subjected to force.

[0122] like Figure 9 As shown, in some embodiments, the slip ring 42 is provided with a plurality of through holes 42a penetrating in the radial direction, and the plurality of through holes 42a are evenly and spaced apart, and each ball 43 is accommodated and confined in a through hole 42a, and each ball 43 is confined in a through hole 42a, and the ball 43 can rotate freely in the through hole 42a, but will not fall out of the slip ring 42, so that the slip ring 42 can realize both rolling rotational motion and rolling linear motion. The provision of the through hole 42a can also prevent the ball 43 from deviating from the predetermined trajectory during the movement, and make the load on the rotating shaft 21 more evenly distributed to each ball 43, and the evenly distributed load reduces the wear of the contact point of a single ball 43, and prolongs the service life of the ball 43.

[0123] It is understandable that the diameter of the ball 43 is greater than the radial thickness of the slip ring 42, and the ratio of the diameter of the ball 43 to the wall thickness of the slip ring 42 is k, and 1.1≤k≤2. If the ratio k is too small, that is, the diameter of the ball 43 is too small relative to the wall thickness of the slip ring 42, the contact area or frequency between the ball 43 and the rotating shaft 21 or the outer ring 41 will be too large, and this excessive contact may increase friction, resulting in energy loss and premature wear. Conversely, if the ratio k is too large, that is, the diameter of the ball 43 is too large relative to the wall thickness of the slip ring 42, the slip ring 42 may not provide sufficient guidance for the ball 43. This may cause the ball 43 to deviate from the predetermined trajectory during movement, affecting the stability and accuracy of the bearing assembly 40. By setting a suitable ratio k, that is, k is greater than or equal to 1.1 and less than or equal to 2, the coordination between the ball 43 and the slip ring 42 can be ensured, the rolling friction between the ball 43 and the slip ring 42 can be optimized, and low-energy and high-efficiency movement can be achieved, thereby extending the service life of the bearing assembly 40.

[0124] like Figure 10 and Figure 11 As shown, in some embodiments, the slip ring 42 has an inner raceway 421 and an outer raceway 422 (such as Figure 15), the inner raceway 421 is arranged on the inner wall surface of the slip ring 42, and the outer raceway 422 is arranged on the outer wall surface of the slip ring 42. The inner raceway 421 and the outer raceway 422 are arranged on the slip ring 42 to effectively utilize the space of the slip ring 42 and realize a compact design. One of the inner raceway 421 and the outer raceway 422 is extended along the axial direction of the rotating shaft 21, and the other of the inner raceway 421 and the outer raceway 422 is extended along the circumferential direction of the slip ring 42. The ball 43 includes an inner ball 431 and an outer ball 432. The ball 431 can be rollably mounted between the inner raceway 421 and the shaft 21, and the outer ball 432 can be rollably mounted between the outer raceway 422 and the outer ring 41. The inner raceway 421 and the outer raceway 422 provide precise rolling paths for the inner ball 431 and the outer ball 432, respectively, and define the movement paths of the inner ball 431 and the outer ball 432, while limiting the inner ball 431 and the outer ball 432 to move only in the inner raceway 421 and the outer raceway 422, respectively, and cannot deviate from the corresponding tracks. The setting of the inner raceway 421 and the outer raceway 422 ensures the guiding accuracy of the movement of the shaft 21, and the setting of the inner ball 431 and the outer ball 432 provides the shaft 21 with rolling freedom in two directions, increases the flexibility of the bearing assembly 40, and supports the multi-directional movement of the shaft 21, including axial extension and circumferential swing.

[0125] like Figure 12 As shown, for example, the inner raceway 421 is a longitudinal raceway extending axially, which can limit the inner ball 431 to move only along the longitudinal raceway, thereby ensuring the rolling friction during the linear telescopic movement of the bearing assembly 40; the outer raceway 422 is a circumferential raceway extending circumferentially, which can limit the outer ball 432 to move only along the longitudinal raceway, thereby ensuring the rolling friction during the circumferential swing of the bearing assembly 40. It is understandable that the inner raceway 421 can also be a circumferential raceway, and the outer raceway 422 can be a longitudinal raceway, and this application does not limit this.

[0126] like Figure 13 and Figure 14 As shown, in some embodiments, the inner raceway 421 is extended along the axial direction of the rotating shaft 21, that is, the inner raceway 421 is a longitudinal raceway, and the length of the inner raceway 421 is greater than or equal to half of the total axial telescopic stroke of the movable subassembly 20 along the rotating shaft 21. If the length of the inner raceway 421 is less than half of the total axial telescopic stroke of the movable subassembly 20 along the rotating shaft 21, it may not be possible to provide a sufficient rolling path for the inner ball 431 during the entire telescopic process, thereby affecting the continuous rolling of the ball 43. The longer inner raceway 421 ensures that even when the movable subassembly 20 is telescoped to the extreme position in the axial direction, the inner ball 431 can still roll stably in the inner raceway 421, providing reliable support and precise guidance.

[0127] Please continue reading Figure 14, due to certain tolerances in the production, manufacturing, and assembly processes, the actual telescopic stroke may deviate from the designed value. The length of the inner raceway 421 is greater than half of the total axial telescopic stroke of the mover assembly 20 along the rotating shaft 21, which can ensure that the inner ball 431 can roll normally even in the presence of tolerances. Considering the design of miniaturizing the bidirectional motion motor, while pursuing the miniaturization of the bidirectional motion motor, it is necessary to balance the length of the inner raceway 421 and the overall size of the bidirectional motion motor. Therefore, the length of the inner raceway 421 can be set to half of the total telescopic stroke of the mover assembly 20 along the rotating shaft 21 plus the length of the cumulative tolerance. The reasonable setting of the length of the inner raceway 421 can avoid excessive increase in length and maintain the compactness of the structure of the bidirectional motion motor.

[0128] In some embodiments, the inner raceway 421 is arranged to extend axially along the rotating shaft 21, that is, the inner raceway 421 is a longitudinal raceway, and the number of longitudinal raceways is four, rather than only setting a single longitudinal raceway, thereby increasing the number of support points. The four longitudinal raceways are evenly spaced circumferentially along the slip ring 42, ensuring that at any position during the telescopic process of the rotating shaft 21, at least one longitudinal raceway provides support. This continuous support reduces the risk of the rotating shaft 21 losing support during movement. When the rotating shaft 21 is subjected to an axial force, the four longitudinal raceways can share this force. In most cases, two adjacent longitudinal raceways will jointly bear the main load. This load sharing mechanism reduces the stress on a single raceway, thereby reducing wear.

[0129] And since at least two longitudinal raceways can share the load, even if one longitudinal raceway is worn or damaged, the other longitudinal raceways can still continue to provide support, which increases the reliability of the entire bearing assembly 40.

[0130] As Figure 14 shown, in some embodiments, the outer raceway 422 is arranged to surround the circumference of the slip ring 42, that is, the outer raceway 422 is a circumferential raceway, and the number of circumferential raceways is two. Compared with the possible instability factors brought about by only setting one circumferential raceway, and when the force is relatively large, setting only one circumferential raceway may cause damage to the outer ball 432 due to overloading. Therefore, setting two circumferential raceways can share the radial force received by the bearing assembly 40, thereby improving the overall load-bearing capacity. And compared with setting three or more circumferential raceways, setting two circumferential raceways can better control the cost.

[0131] And the two circumferential raceways are arranged at an axial interval, which helps to distribute the load more evenly, reduce the local wear of the outer ball 432 and the outer raceway 422, and extend the service life of the bearing assembly 40.

[0132] As Figure 15As shown, in some embodiments, the bearing assembly 40 further includes an inner cage 44. The inner cage 44 is located between the rotating shaft 21 and the inner raceway 421. The inner cage 44 is provided with a first load-bearing hole 44a for accommodating the inner ball 431, ensuring that the inner ball 431 maintains a correct position during rolling and preventing the inner ball 431 from shifting or being misaligned. The inner cage 44 can limit the vibration of the inner ball 431, reducing noise or vibration caused by the collision or improper position of the inner ball 431. The inner cage 44 can also provide additional support and guidance for the inner ball 431, enhancing the reliability of the bearing assembly 40 during long-term use.

[0133] In some embodiments, the inner raceway 421 extends along the axial direction of the rotating shaft 21, that is, the inner raceway 421 is a longitudinal raceway. Two inner balls 431 are arranged on the longitudinal raceway. The two inner balls 431 jointly bear the load. Compared with only setting a single inner ball 431, a greater axial force can be borne, thereby improving the load-bearing capacity of the entire bearing assembly 40.

[0134] Please continue to refer to Figure 15 , further, in order to prevent the two inner balls 431 from gathering together during operation, the inner cage 44 is a longitudinal cage. The longitudinal cage is in the shape of a thin sheet. The longitudinal cage is provided with two first load-bearing holes 44a. The two first load-bearing holes 44a are arranged at intervals along the axial direction of the rotating shaft 21, capable of maintaining the distance between the two inner balls 431 and making the operation of the bearing assembly 40 more stable. If the longitudinal cage is not provided, the two inner balls 431 will gather together during operation, and the balance of force will become worse. At this time, the effect is equivalent to only setting one inner ball 431. Therefore, setting the longitudinal cage reduces the unbalanced force generated due to the gathering of the inner balls 431.

[0135] And the two first load-bearing holes 44a are symmetrically arranged with respect to the central axis of the longitudinal cage, so that the two inner balls 431 evenly share the load and reduce local stress concentration. The symmetrical arrangement also helps to reduce the eccentric moment during the movement of the rotating shaft 21, thereby improving the dynamic stability of the bearing assembly 40.

[0136] As Figure 15 shown, in some embodiments, the bearing assembly 40 further includes an outer cage 45. The outer cage 45 is located between the outer ring 41 and the outer raceway 422. The outer cage 45 is provided with a second load-bearing hole 45a for accommodating the outer ball 432. The outer cage 45 is used to limit the outer ball 432, ensuring the stable operation of the outer ball 432 in the outer raceway 422, preventing the outer ball 432 from being misaligned or derailed, and the outer cage 45 can keep the outer ball 432 running in the correct position, improving the smoothness of the bearing assembly 40 during operation.

[0137] In some embodiments, the outer raceway 422 is circumferentially arranged around the slip ring 42, that is, the outer raceway 422 is a circumferential raceway. Four outer ball bearings 432 can be arranged on the circumferential raceway. The four outer ball bearings 432 are evenly spaced in the circumferential direction of the outer raceway 422 and can jointly bear the load. That is, the spacing between two adjacent outer ball bearings 432 is arranged at 90°, which can bear the load from different directions more evenly and reduce the stress concentration of a single outer ball bearing 432. Especially during high-speed rotation, the stability and balance of the bearing assembly 40 can be maintained.

[0138] Please continue to refer to Figure 15 , further, in order to prevent the four outer ball bearings 432 from gathering together during operation, the outer cage 45 is an annular cage. The annular cage is provided with a plurality of second bearing holes 45a, and the plurality of second bearing holes 45a are evenly spaced along the circumferential direction of the annular cage. The number of the plurality of second bearing holes 45a can be four. During rotational movement, the annular cage rotates together with the rotation of the outer ball bearings 432, which does not affect the rolling of the outer ball bearings 432 and at the same time maintains the spacing between the plurality of outer ball bearings 432. If the annular cage is not provided, during the movement process, the plurality of outer ball bearings 432 will gather together, causing a jamming problem, ensuring the smooth movement of the bearing assembly 40.

[0139] In some embodiments, the slip ring 42 has an inner arc-shaped raceway and an outer arc-shaped raceway. The inner arc-shaped raceway is arranged on the inner wall surface of the slip ring 42, and the outer arc-shaped raceway is arranged on the outer wall surface of the slip ring 42; the ball bearings 43 include inner ball bearings 431 and outer ball bearings 432. The inner ball bearings 431 are rotatably installed between the inner arc-shaped raceway and the rotating shaft 21, and the outer ball bearings 432 are rotatably installed between the outer arc-shaped raceway and the outer ring 41, which can enable the inner ball bearings 431 and the outer ball bearings 432 to evenly bear the load. The inner arc-shaped raceway and the outer arc-shaped raceway provide a smooth movement track, making the inner ball bearings 431 and the outer ball bearings 432 more stable during the rolling process. Arranging the inner arc-shaped raceway and the outer arc-shaped raceway can adapt to complex movement modes and help improve the dynamic response performance of the bearing assembly 40, quickly adapting to load changes and changes in the movement direction.

[0140] Such as Figure 14 and Figure 15As shown, in some embodiments, the slip ring 42 needs to be sleeved on the rotating shaft 21. The slip ring 42 is provided with corresponding first jacks 42b. To prevent the longitudinal cages and inner balls 431 at the two axial end faces of the slip ring 42 from falling off, the bearing assembly 40 further includes a stopper 46. Axially, the radial cross-section of the stopper 46 is annular, and the stopper 46 is in interference fit with the inner wall of the first jack 42b, which is used to limit the longitudinal cage and the inner ball 431 from disengaging from the inner raceway 421, making the bearing assembly 40 more reliable during use and reducing the risk of accidental failures. Moreover, the presence of the stopper 46 enhances the structural rigidity of the bearing assembly 40, making the bearing assembly 40 more stable when bearing loads.

[0141] Understandably, two stoppers 46 are provided, and the two stoppers 46 are respectively located at the two axial ends of the slip ring 42 to prevent the longitudinal cage and the inner balls 431 from falling off from the two axial ends of the slip ring 42.

[0142] Exemplarily, the stopper 46 can be a copper ring. The copper ring has sufficient mechanical strength. After being press-fitted into the slip ring 42, it can reliably limit the axial displacement of the longitudinal cage. Moreover, the copper ring is easy to process and can be manufactured into appropriate sizes and shapes to meet the requirements of the bearing assembly 40 for the size and shape of the stopper 46.

[0143] As Figure 10 and Figure 11 shown, in some embodiments, the bi-directional movement motor 100 further includes a retaining ring 50. Axially, the radial cross-section of the retaining ring 50 is annular. The retaining ring 50 is in interference fit with the inner wall surface of the outer ring 41 and is sleeved on the periphery of the rotating shaft 21 to limit the axial movement stroke of the slip ring 42, effectively preventing the slip ring 42 from falling off. By controlling the axial movement range of the slip ring 42, unnecessary contact and wear between the slip ring 42 and other components are reduced, thereby extending the service life of the bearing assembly 40.

[0144] As Figure 12 shown, understandably, two retaining rings 50 are provided, and the two retaining rings 50 are arranged axially spaced along the outer ring 41, while the slip ring 42 is arranged between the two retaining rings 50 to ensure the movement position of the slip ring 42 on the rotating shaft 21 and avoid the axial crosstalk of the slip ring 42.

[0145] As Figure 11 and Figure 12 shown, in some embodiments, the retaining ring 50 is provided with a second jack 50a, and the rotating shaft 21 passes through the second jack 50a. Among them, the diameter of the second jack 50a is smaller than the diameter of the slip ring 42. By restricting the axial movement range of the slip ring 42, it is ensured that when the slip ring 42 is sleeved on the rotating shaft 21 and located between the two retaining rings 50, it will not be easily slipped out of the second jack 50a of the retaining ring 50, thereby effectively preventing the slip ring 42 from falling off.

[0146] As Figure 6 and Figure 7 shown, in some embodiments, when the rotating shaft 21 swings, the slip ring 42 can roll freely in the circumferential direction. When the rotating shaft 21 expands and contracts, the slip ring 42 also moves along with the forward and backward movement of the rotating shaft 21. The distance between two opposite wall surfaces of the two snap rings 50 is D1, and the total expansion and contraction of the mover assembly 20 along the axial direction of the rotating shaft 21 is X1. Among them, D1≥X1 / 2, which can ensure that the slip ring 42 can roll normally during the expansion and contraction movement of the rotating shaft 21 without being blocked due to insufficient space.

[0147] And when designing, considering the errors in production manufacturing and processes, a part of the margin will be added on the basis of the minimum moving distance to ensure that the slip ring 42 can roll freely even with variations within the tolerance range. And considering the miniaturized design of the bidirectional motion motor, the distance D1 between two opposite wall surfaces of the two snap rings 50 should not be increased excessively. Therefore, in actual design, the value of D1 can be taken as half of the total expansion and contraction stroke of the mover assembly 20 along the rotating shaft 21 plus the length of the cumulative tolerance.

[0148] Furthermore, the distance between two opposite wall surfaces of the two snap rings 50 is D1, that is, the range within which the slip ring 42 can move. The length of the slip ring 42 is L1, and the total expansion and contraction stroke of the mover assembly 20 along the axial direction of the rotating shaft 21 is X1. D1 - L1≥X1. This enables the slip ring 42 not to frequently hit the snap ring 50 during the movement process, reduces the wear rate of the snap ring 50 and the slip ring 42 caused by the impact, and improves the durability of the bearing assembly 40.

[0149] Please continue to refer to Figure 7 , in some embodiments, the snap ring 50 is arranged at a radial interval from the rotating shaft 21 along the radial direction of the rotating shaft 21, reducing the direct contact between the rotating shaft 21 and the snap ring 50 during the axial and circumferential movements of the rotating shaft 21, reducing the wear, and extending the service life of the snap ring 50 and the rotating shaft 21. And the rotating shaft 21 will not be blocked by the snap ring 50 during the axial and circumferential movements, ensuring the smoothness and continuity of the movement of the rotating shaft 21.

[0150] During the actual assembly process, first install the slip ring 42 into the outer ring 41, and then embed the two snap rings 50 into both axial ends of the outer ring 41 in an interference fit manner to limit the slip ring 42 axially.

[0151] As Figure 7 and Figure 8As shown, since the hardness of the rotating shaft 21 is relatively low compared to that of the ball 43, if the rotating shaft 21 directly contacts the ball 43, when extreme situations such as dropping occur, the ball 43 will directly impact the rotating shaft 21, thereby generating pits on the rotating shaft 21 and causing relatively large resistance. Therefore, to solve the above problems, in some embodiments, the bearing assembly 40 further includes an inner ring 47. The inner ring 47 is sleeved on the rotating shaft 21 and fixedly connected to the rotating shaft 21. The inner ring 47 is made of high-hardness steel. Among them, the slip ring 42 can slide relative to the inner ring 47 and the outer ring 41, and the ball 43 can roll and abut against the outer wall of the inner ring 47 and the inner wall of the outer ring 41. That is, the design of the inner ring 47 plays a role in protecting the rotating shaft 21, can improve the impact resistance of the part of the rotating shaft 21 sleeved with the inner ring 47, and the inner ring 47 has a smooth surface, which can further reduce the friction resistance of the ball 43, thereby improving the operating efficiency of the bearing assembly 40.

[0152] In the actual assembly process, the inner ring 47 and the rotating shaft 21 are in interference fit, and then fixed by means of dotting. During the movement of the rotating shaft 21, the inner ring 47 is driven to move together, that is, the inner ring 47 can move axially along the rotating shaft 21 and rotate circumferentially around the rotating shaft 21 relative to the outer ring 41.

[0153] Please continue to refer to Figure 8 , in some embodiments, since the inner ring 47 moves axially back and forth with the rotating shaft 21, if the length of the inner ring 47 is relatively short, the two ends of the inner ring 47 may enter between the two retaining rings 50 during the movement. When moving axially back and forth again, the end of the inner ring 47 may interfere with the adjacent retaining ring 50. Therefore, along the axial direction of the rotating shaft 21, the length of the inner ring 47 is greater than or equal to the length of the outer ring 41, reducing the possibility of collision between the two ends of the inner ring 47 and the retaining ring 50, thereby avoiding possible movement obstacles, reducing the wear of the inner ring 47 and the retaining ring 50, and prolonging the service life of the inner ring 47 and the retaining ring 50.

[0154] Furthermore, as the inner ring 47 moves axially back and forth with the rotating shaft 21, the length of the inner ring 47 is set to be greater than or equal to the length of the outer ring 41, that is, during the reciprocating translation process, the ball 43 can maintain rolling contact with the inner ring 47, reducing the risk of ball 43 deviation.

[0155] Such as Figure 6 and Figure 7 shown, in some embodiments, the difference between the length of the inner ring 47 and the length of the outer ring 41 is greater than or equal to the amplitude of the rotating shaft 21, avoiding interference between the inner ring 47 and the retaining ring 50 when the rotating shaft 21 moves axially back and forth, and reducing the risk of mechanical failure of the bidirectional motion motor 100.

[0156] To prevent friction from occurring between the retaining ring 50 and the inner ring 47 when the rotating shaft 21 undergoes axial telescoping and circumferential swinging, in some embodiments, the retaining ring 50 and the inner ring 47 are spaced apart along the radial direction of the rotating shaft 21, reducing the chance of direct contact between the retaining ring 50 and the inner ring 47, thereby significantly reducing friction. And reducing unnecessary frictional force can improve the movement precision of the rotating shaft 21 and ensure its swinging and translation along a predetermined trajectory.

[0157] In a second aspect, an embodiment of the present application further relates to an electric toothbrush, which includes a handle housing, a brush head, and a bidirectional movement motor 100 in any of the above embodiments. The handle housing provides a gripping portion, and the internal space of the handle housing can be used to accommodate a battery, a control circuit, etc. The bidirectional movement motor 100 is disposed inside the handle housing, one end of the rotating shaft 21 is disposed inside the handle housing, and the other end passes through the handle housing and is located outside the handle housing; the brush head is the part of the electric toothbrush that directly contacts the user's teeth, and the brush head is connected to the end of the rotating shaft 21 located outside the handle housing. The bidirectional movement motor 100 can achieve the axial telescoping and circumferential swinging of the brush head. This compound movement mode can provide a more comprehensive tooth cleaning effect. The multi-directional movement of the brush head helps to deeply clean the tooth gaps and the tooth surface, achieving a more efficient cleaning effect.

[0158] In the drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components; in the description of the present application, it should be understood that if there are terms such as "upper", "lower", "left", "right", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and should not be construed as a limitation of the present application. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0159] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A bidirectional motion motor, characterized in that: include: chassis; A moving subassembly is arranged in the housing and has a rotating shaft; A stator assembly is disposed in the housing and is used to drive the mover assembly to reciprocate along the circumference of the rotating shaft, and to drive the mover assembly to extend and retract along the axial direction of the rotating shaft; as well as A bearing assembly, the bearing assembly comprising: An outer ring, fixedly connected to the housing; a slip ring, movably disposed between the outer ring and the rotating shaft; and A plurality of balls movably connected to the slip ring; Among them, the rotating shaft rolls with the outer ring through the ball, so that the rotating shaft can perform the circumferential reciprocating swing and the axial expansion and contraction relative to the outer ring; when the rotating shaft performs the circumferential reciprocating swing and the axial expansion and contraction, the outer ring remains relatively fixed with the casing in the axial direction and the circumferential direction.

2. The bidirectional motion motor according to claim 1, characterized in that: The slip ring is provided with a plurality of through holes, and the plurality of through holes are arranged at intervals; Each of the balls is accommodated and limited in one of the through holes, and is in rolling contact with the rotating shaft and the outer ring respectively.

3. The bidirectional motion motor according to claim 2, characterized in that: The ratio of the diameter of the ball to the wall thickness of the slip ring is k, and 1.1≤k≤2.

4. The bidirectional motion motor according to claim 1, characterized in that: The plurality of balls are symmetrically arranged along the axial midplane of the slip ring.

5. The bidirectional motion motor according to claim 1, characterized in that: The plurality of balls are arranged in four rows along the circumference of the slip ring, and the balls in the four rows are evenly spaced along the circumference of the slip ring; The number of the balls in each row is two, and the two balls in the same row are symmetrically arranged along the radial midplane of the slip ring.

6. The bidirectional motion motor according to claim 1, characterized in that: The slip ring has an inner raceway and an outer raceway, the inner raceway is arranged on the inner wall surface of the slip ring, and the outer raceway is arranged on the outer wall surface of the slip ring; One of the inner raceway and the outer raceway is arranged to extend in the axial direction of the rotating shaft, and the other of the inner raceway and the outer raceway is arranged to extend in the circumferential direction of the slip ring; The balls include inner balls and outer balls. The inner balls are rollably mounted between the inner raceway and the rotating shaft, and the outer balls are rollably mounted between the outer raceway and the outer ring.

7. The bidirectional motion motor according to claim 6, characterized in that: The inner raceway is extended along the axial direction of the rotating shaft, and the length of the inner raceway is greater than or equal to half of the total axial telescopic stroke of the mover assembly along the rotating shaft.

8. The bidirectional motion motor according to claim 6, characterized in that: The inner raceway is extended along the axial direction of the rotating shaft, the number of the inner raceways is four, and the four inner raceways are evenly spaced along the circumferential direction of the slip ring.

9. The bidirectional motion motor according to claim 6, characterized in that: The outer raceway is arranged around the circumference of the slip ring, the number of the outer raceways is two, and the two outer raceways are arranged at intervals along the axial direction of the rotating shaft.

10. The bidirectional motion motor according to claim 6, characterized in that: The bearing assembly further comprises: The inner retainer is located between the rotating shaft and the inner raceway. The inner retainer is provided with a first bearing hole. The first bearing hole is used to accommodate the inner ball. The inner retainer is used to limit the inner ball.

11. The bidirectional motion motor according to claim 10, characterized in that: The inner raceway is extended along the axial direction of the rotating shaft, the inner retainer is a longitudinal retainer, and the longitudinal retainer is provided with two first bearing holes, the two first bearing holes are arranged at intervals along the axial direction of the rotating shaft, and the two first bearing holes are symmetrically arranged with respect to the central axis of the longitudinal retainer.

12. The bidirectional motion motor according to claim 11, characterized in that: The slip ring is provided with a first plug hole, and the bearing assembly further comprises: A stopper is formed in interference fit with a hole wall of the first insertion hole, and is used to limit the longitudinal retainer from being separated from the inner raceway.

13. The bidirectional motion motor according to claim 6, characterized in that: The bearing assembly further comprises: The outer retainer is located between the outer ring and the outer raceway. The outer retainer is provided with a second bearing hole, the second bearing hole is used to accommodate the outer ball, and the outer retainer is used to limit the outer ball.

14. The bidirectional motion motor according to claim 13, characterized in that: The outer raceway is arranged around the circumference of the slip ring, the outer retainer is an annular retainer, and a plurality of the second bearing holes are arranged on the annular retainer, and the plurality of the second bearing holes are evenly spaced along the circumference of the annular retainer.

15. The bidirectional motion motor according to claim 14, characterized in that: The annular retaining frame is provided with four second bearing holes.

16. The bidirectional motion motor according to claim 1, characterized in that: The slip ring has an inner arc-shaped raceway and an outer arc-shaped raceway, the inner arc-shaped raceway is arranged on the inner wall surface of the slip ring, and the outer arc-shaped raceway is arranged on the outer wall surface of the slip ring; The balls include inner balls and outer balls. The inner balls are rollably mounted between the inner arc-shaped raceway and the rotating shaft, and the outer balls are rollably mounted between the outer arc-shaped raceway and the outer ring.

17. The bidirectional motion motor according to any one of claims 1 to 16, characterized in that: The bidirectional motion motor also includes: The retaining ring is interference-fitted with the inner wall surface of the outer ring and is sleeved on the circumferential side of the rotating shaft to limit the axial movement stroke of the slip ring.

18. The bidirectional motion motor according to claim 17, characterized in that: The retaining ring and the rotating shaft are spaced apart from each other along the radial direction of the rotating shaft.

19. The bidirectional motion motor according to claim 17, characterized in that: The retaining ring is provided with a second plug hole, and the rotating shaft is passed through the second plug hole; Wherein, the diameter of the second plug hole is smaller than the diameter of the slip ring.

20. The bidirectional motion motor according to claim 17, characterized in that: Two retaining rings are provided, and the two retaining rings are arranged at intervals along the axial direction of the outer ring, and the slip ring is arranged between the two retaining rings.

21. The bidirectional motion motor according to claim 20, characterized in that: The distance between two opposite wall surfaces of the two retaining rings is D1, the length of the slip ring is L1, the total telescopic stroke of the mover assembly along the axial direction of the rotating shaft is X1, and D1-L1≥X1.

22. The bidirectional motion motor according to claim 20, characterized in that: The distance between the two opposite wall surfaces of the two retaining rings is D1, and the total telescopic stroke of the movable component along the axial direction of the rotating shaft is X1, and D1≥X1 / 2.

23. The bidirectional motion motor according to any one of claims 1 to 16, characterized in that: The bearing assembly further comprises: An inner ring, sleeved on the rotating shaft and fixedly connected to the rotating shaft; The balls roll against the outer wall of the inner ring and the inner wall of the outer ring.

24. The bidirectional motion motor according to claim 23, characterized in that: Along the axial direction of the rotating shaft, the length of the inner ring is greater than or equal to the length of the outer ring.

25. The bidirectional motion motor according to claim 23, characterized in that: The difference between the length of the inner ring and the length of the outer ring is greater than or equal to the amplitude of the rotating shaft.

26. The bidirectional motion motor according to claim 23, characterized in that: The bidirectional motion motor also includes: A retaining ring, the outer peripheral side of which is clamped in the outer ring and sleeved on the peripheral side of the rotating shaft to limit the movement stroke of the slip ring in the axial direction; Wherein, the retaining ring is arranged between the outer ring and the inner ring along the radial direction of the rotating shaft, and the retaining ring and the inner ring are arranged at intervals along the radial direction of the rotating shaft.

27. An electric toothbrush, characterized in that: include: A bidirectional motion motor as claimed in any one of claims 1 to 26; a handle shell, wherein the bidirectional motion motor is disposed in the handle shell, one end of the rotating shaft is disposed in the handle shell, and the other end is penetrated through the handle shell and is located outside the handle shell; and A brush head is connected to one end of the rotating shaft located outside the handle shell.

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