Motor and oral cavity cleaning equipment

Abstract

The utility model discloses a motor and oral cavity cleaning equipment. The motor comprises a stator assembly and a rotor assembly. The stator assembly comprises at least one pair of stator core bodies; the rotor assembly comprises a power shaft and a magnet assembly; each magnet assembly is configured to comprise a first magnet and a second magnet which are arranged in the circumferential direction of the power shaft and matched with the same stator core body, and at least part, close to the stator core body, of the first magnet and at least part, close to the stator core body, of the second magnet are configured to have different polarities; when the magnet assembly is located at the balance position, the ratio range of the central angle corresponding to the overlapped part of the single magnet in the magnet assembly and the projection of the stator core body to the half of the central angle corresponding to the inner arc of the stator core body facing the magnet assembly is 40%-70%.

Description

Technical Field

[0001] The utility model relates to the technical field of motors, and in particular to a motor and an oral cleaning device having the motor. Background Art

[0002] A motor is an electromagnetic device that converts or transmits electrical energy based on the law of electromagnetic induction.

[0003] Oral cleaning devices utilize a high-speed vibrating motor shaft to drive the brush head to oscillate or vibrate, effectively cleaning teeth. This high-frequency vibration of the motor breaks down toothpaste into fine foam, deeply cleaning between teeth. This provides a stronger cleaning capability than traditional toothbrushes. Currently, the vibration frequency of the motor in oral cleaning devices is typically above 200 Hz.

[0004] In addition, the motor of the current oral cleaning equipment drives the brush head to swing at a small angle, which generally does not exceed 10°, making it difficult to meet the teeth cleaning needs of different consumers.

[0005] Based on this, how to provide a motor with a larger swing angle for use in oral cleaning equipment has become a technical problem that needs to be solved urgently. Utility Model Content

[0006] The embodiments of this specification propose a motor to solve the problem that the swing angle of the motor in the existing oral cleaning device is small, which affects the user experience.

[0007] To solve the above technical problems, an embodiment of this specification provides a motor, comprising:

[0008] a stator assembly arranged to generate a magnetic field, wherein the stator assembly comprises at least one stator core;

[0009] a rotor assembly at least partially arranged within the magnetic field of the stator assembly, the rotor assembly comprising a power shaft and a magnet assembly disposed on the power shaft and cooperating with the stator core; each magnet assembly being configured to include a first magnet and a second magnet arranged circumferentially around the power shaft and cooperating with the same stator core, wherein at least a portion of the first magnet proximate to the stator core and at least a portion of the second magnet proximate to the stator core are configured to have different polarities;

[0010] When in a balanced position, the first magnet and the second magnet correspond to two sides of the stator core respectively, and the first magnet overlaps with the central projection of the stator core in the radial direction, and the second magnet overlaps with the central projection of the stator core in the radial direction;

[0011] The ratio of a first central angle corresponding to the overlapping portion of the projection of the first magnet and the stator core to half of a second central angle corresponding to the inner arc of the stator core facing the magnet assembly is in a range of 40% to 70%; and / or,

[0012] The ratio of the third central angle corresponding to the overlapping portion of the projection of the second magnet and the stator core to half of the second central angle is in a range of 40% to 70%; and / or,

[0013] The first central angle is the same as the third central angle.

[0014] Optionally, in a plane perpendicular to the rotation axis of the rotor assembly, a ratio of a fourth central angle corresponding to the outer circular arc of the stator core faced by the first magnet to the second central angle is in a range of 60% to 85%; a ratio of a fifth central angle corresponding to the outer circular arc of the stator core faced by the second magnet to the second central angle is in a range of 60% to 85%.

[0015] Optionally, in a plane perpendicular to the rotation axis of the rotor assembly, the ratio of the arc length of the outer arc of the first magnet facing the stator core to the arc length of the inner arc of the stator core facing the magnet assembly is in a range of 60% to 70%; the ratio of the arc length of the outer arc of the second magnet facing the stator core to the arc length of the inner arc of the stator core facing the magnet assembly is in a range of 60% to 70%.

[0016] Optionally, among the planes containing the rotation axis of the rotor assembly, at least one plane is a symmetry plane; the stator core is mirror-symmetrically arranged with the symmetry plane as a reference plane, and / or the first magnet and the second magnet are mirror-symmetrically arranged with the symmetry plane as a reference plane.

[0017] Optionally, the ratio of the first central angle to the fourth central angle ranges from 30% to 45%; the ratio of the third central angle to the fifth central angle ranges from 30% to 45%.

[0018] Optionally, the ratio of the first central angle to the fourth central angle ranges from 35% to 40%; the ratio of the third central angle to the fifth central angle ranges from 35% to 40%.

[0019] Optionally, in a plane perpendicular to the rotation axis of the rotor assembly, the first angle between the center line of the first magnet and the center line of the second magnet ranges from 73° to 87°; the center line of the first magnet is a line pointing from the center of the first magnet to the rotation axis, and the center line of the second magnet is a line pointing from the center of the second magnet to the rotation axis.

[0020] Optionally, the first magnet and the second magnet are both arc-shaped, including an outer arc and an inner arc distributed in the radial direction, and two side edges connecting the corresponding ends of the outer arc and the inner arc respectively; the central angles of the outer arc and the inner arc are the same.

[0021] Optionally, the width of the air gap between the outer arcs of the first magnet and the second magnet and the inner arc of the stator core facing the magnet assembly ranges from 0.15 mm to 0.25 mm.

[0022] Optionally, the thickness of the first magnet and the second magnet are both within a preset thickness range; the preset thickness range is 1 mm to 2 mm; the thickness of the first magnet and the second magnet is the radial distance between the outer arc and the inner arc.

[0023] Optionally, the thickness of the first magnet and the second magnet are both 1.5 mm.

[0024] Optionally, the first magnet and the second magnet are arranged around the circumference of the power shaft at a preset central angle interval.

[0025] Optionally, the preset central angle ranges from 23.5° to 38°.

[0026] Optionally, the preset central angle is 28.5°.

[0027] Optionally, the motor includes a motor housing; the rotor assembly is arranged in the motor housing.

[0028] Optionally, a limit member is provided on the motor housing; the limit member is used to prevent the rotor assembly from rotating beyond a preset angle threshold.

[0029] Optionally, the power shaft includes an output shaft and a magnetic conductive member.

[0030] Optionally, the power shaft includes a mounting groove; the mounting groove is used to install the magnet assembly.

[0031] Optionally, the number of the mounting slots is 4.

[0032] Optionally, the groove depth of the mounting groove is 0.7 mm.

[0033] Optionally, the magnets in the magnet assembly are embedded in the mounting grooves by adhesive.

[0034] Optionally, the motor includes an electromagnetic coil disposed around the stator core, and in response to a control signal applied to the electromagnetic coil, the stator core causes the rotor assembly to rotate relative to the stator core about a rotation axis of the rotor assembly.

[0035] Optionally, the stator core causes the rotor assembly to rotate unidirectionally around the rotation axis relative to the stator core in an angle range of 0° to 20°; the stator core causes the rotor assembly to rotate bidirectionally around the rotation axis relative to the stator core in an angle range of 0° to 40°.

[0036] Optionally, two stator cores are provided, and the two stator cores are constructed to be symmetrically distributed; two magnet assemblies are provided; each magnet assembly corresponds to one stator core; and the third angle between the two magnet assemblies is greater than the second angle between the first magnet and the second magnet in the magnet assembly.

[0037] Optionally, the frequency range of the motor in operation is 100 Hz to 180 Hz.

[0038] Optionally, the frequency range of the motor in operation is 140 Hz to 150 Hz.

[0039] The embodiment of this specification also provides an oral cleaning device, which has the motor.

[0040] At least one embodiment of the present specification can achieve the following beneficial effects: by setting a reasonable ratio range between the central angle corresponding to the overlapping portion of the projection of the magnet and the stator core in the rotor assembly and the central angle corresponding to the inner arc of the stator core facing the magnet when in the equilibrium position, the cogging torque can be reduced so that the swing angle of the rotor assembly can be increased while the motor output torque remains essentially unchanged, thereby facilitating the satisfaction of different consumers' tooth cleaning needs. Furthermore, the vibration frequency of the motor can be reduced, thereby avoiding the user's prominent toothache, soreness, and other sensations caused by high-frequency vibration, and avoiding the increase in motor noise caused by high-frequency vibration, thereby improving the user's experience of using an oral cleaning device with such a motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0042] Figure 1 A schematic diagram of the internal structure of a motor provided in an embodiment of this specification;

[0043] Figure 2A schematic diagram of the overall structure of a motor provided in an embodiment of this specification;

[0044] Figure 3 A schematic diagram of the structure of the first central angle and the third central angle provided in the embodiments of this specification;

[0045] Figure 4 A schematic diagram of the structure of the second central angle provided in the embodiment of this specification;

[0046] Figure 5 A schematic diagram of the structure of the fourth central angle and the fifth central angle provided in the embodiments of this specification;

[0047] Figure 6 A schematic structural diagram of the first angle provided in the embodiment of this specification;

[0048] Figure 7 A schematic diagram of the structure of the second angle and the third angle provided in the embodiments of this specification;

[0049] Figure 8 A schematic structural diagram of a first magnet provided in an embodiment of this specification;

[0050] Figure 9 A schematic diagram of the structure of a power shaft provided in an embodiment of this specification;

[0051] Figure 10 A schematic diagram of the distribution of simulation data of the motor cogging torque provided in the embodiments of this specification;

[0052] Figure 11 A schematic diagram of the distribution of simulation data of motor torque provided in the embodiments of this specification.

[0053] Figure numerals: 1. stator assembly, 11. stator core, 2. rotor assembly, 21. power shaft; 211. rotor core, 2111. mounting slot, 212. output shaft, 22. magnet assembly, 221. first magnet, 2211. outer arc, 2212. inner arc, 2213. side, 222. second magnet, 223. first central angle, 224. second central angle, 225. third central angle, 226. fourth central angle, 227. fifth central angle, 228. first included angle, 229. second included angle, 230. third included angle, 3. motor housing, 31. limiter, 4. air gap, 5. electromagnetic coil. DETAILED DESCRIPTION

[0054] To make the purpose, technical solutions, and advantages of one or more embodiments of the present invention more clear, the technical solutions of one or more embodiments of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of one or more embodiments of the present invention.

[0055] The present disclosure provides a motor that can be used in oral cleaning devices or care devices such as electric toothbrushes. Of course, it can also be used in other electronic devices that require reciprocating swinging, which are not listed here one by one. The motor of the present disclosure includes a motor body, and a stator assembly and a rotor assembly disposed on the motor body.

[0056] The stator assembly is provided on the motor body and is arranged to generate a magnetic field. The stator assembly includes at least one stator core, which can be fixed on the motor body to provide a magnetic field for the motor. There can be one stator core, or two or more stator cores; when there are two or more stator cores, the stator cores are usually evenly arranged in the circumferential direction of the rotor assembly to facilitate the cyclic rotation or reciprocating swing of the rotor assembly. In a specific embodiment of the present disclosure, the stator core may include a stator core and an electromagnetic coil cooperated with the stator core, and when the electromagnetic coil is energized, an alternating magnetic field can be generated for the motor.

[0057] The rotor assembly disclosed herein includes a power shaft and a magnet assembly disposed on the power shaft and engaged with each stator core. The power shaft can be rotatably connected to the motor body via a bearing or other structure, allowing the power shaft to rotate relative to the motor body. Each magnet assembly is configured to include a first magnet and a second magnet arranged circumferentially around the power shaft and engaged with the same stator core. That is, each stator core engages with two magnets simultaneously. For example, the first magnet and the second magnet correspond to portions on either side of the same end of the stator core, and at least the portion of the first magnet proximate the stator core and at least the portion of the second magnet proximate the stator core are configured to have different polarities. For example, when the end of the first magnet facing the stator core is an S pole, the end of the second magnet facing the stator core is an N pole, and vice versa. Thus, when the electromagnetic coil is energized to generate a magnetic field, the magnet assembly can be caused to rotate back and forth by a predetermined angle under the influence of the magnetic field, thereby achieving reciprocating oscillation of the motor.

[0058] In the motor disclosed in the present invention, the ends of the first magnet and the second magnet facing the stator core are in the shape of an arc, and correspondingly, the end of the stator core facing the first magnet and the second magnet is also in the shape of an arc. Wherein, when in the equilibrium position, the first magnet and the second magnet correspond to the two sides of the stator core respectively, and the first magnet and the second magnet both overlap with the radial center projection of the stator core. The ratio of the first center angle corresponding to the overlapping part of the projection of the first magnet and the stator core to half of the second center angle corresponding to the inner arc of the stator core facing the magnet assembly is in the range of 40% to 70%; and / or, the ratio of the third center angle corresponding to the overlapping part of the projection of the second magnet and the stator core to half of the second center angle is in the range of 40% to 70%; and / or, the first center angle is the same as the third center angle.

[0059] In existing technologies, the vibration frequency of the motors in oral cleaning devices (such as electric toothbrushes) is typically higher than 200 Hz. On the one hand, high-frequency vibration can negatively impact the user experience for those with sensitive teeth, causing prominent sensations such as toothache and soreness. On the other hand, high-frequency vibration increases motor noise, impacting the user experience. Furthermore, the motors in current oral cleaning devices drive the brush heads to swing at a relatively small angle, typically no more than 10°, making it difficult to meet the diverse cleaning needs of different consumers.

[0060] In the motor disclosed in the present invention, by optimizing the ratio range of the central angle corresponding to the overlapping portion of the projection of the magnet and the stator core in the rotor assembly in the equilibrium position and the central angle corresponding to the inner arc of the stator core facing the magnet, the cogging torque of the motor can be reduced, so that the swing angle of the rotor assembly can be increased while the output torque of the motor remains basically unchanged. When the motor disclosed in the present invention is applied to oral cleaning devices such as electric toothbrushes, the increased swing angle of the rotor assembly is conducive to meeting the tooth cleaning needs of different consumers. In addition, the vibration frequency of the motor can also be reduced, thereby avoiding the situation where the user has prominent sensations such as toothache and tooth acid due to high-frequency vibration, and can also avoid the situation where the motor noise increases due to high-frequency vibration, which is conducive to improving the user's experience of using oral cleaning devices with such a motor.

[0061] The technical solutions provided by the embodiments of this specification are described in detail below with reference to the accompanying drawings.

[0062] The embodiments of this specification provide a motor that can be used in an oral cleaning device so that the oral cleaning device can work based on the motor to clean teeth and gums and protect oral health.

[0063] Figure 1 A schematic diagram of the internal structure of a motor provided in an embodiment of this specification. Figure 2 This is a schematic diagram of the overall structure of a motor provided in the embodiment of this specification. Figure 1 and Figure 2 As shown, an embodiment of the present specification provides an electric motor, which may include: a stator assembly 1, which is arranged to generate a magnetic field, wherein the stator assembly 1 includes at least one stator core 11; and a rotor assembly 2 at least partially arranged in the magnetic field of the stator assembly 1, the rotor assembly 2 may include a power shaft 21 and a magnet assembly 22 arranged on the power shaft 21 and cooperating with the stator core 11; each magnet assembly 22 is configured to include a first magnet 221 and a second magnet 222 arranged circumferentially around the power shaft 21 and cooperating with the same stator core 11, and at least a portion of the first magnet 221 close to the stator core 11 and at least a portion of the second magnet 222 close to the stator core 11 are constructed to have different polarities.

[0064] Figure 3 This is a schematic diagram of the structure of the first central angle and the third central angle provided in the embodiments of this specification. Figure 4 This is a schematic diagram of the structure of the second central angle provided in the embodiment of this specification. Figure 3 and Figure 4 As shown, when in the equilibrium position, the first magnet 221 and the second magnet 222 correspond to the two sides of the stator core 11 respectively, and the first magnet 221 partially overlaps with the central projection of the stator core 11 in the radial direction, and the second magnet 222 partially overlaps with the central projection of the stator core 11 in the radial direction. The ratio of a first central angle 223 corresponding to the overlapping portion of the projection of the first magnet 221 and the stator core 11 to half of a second central angle 224 corresponding to the inner arc of the stator core 11 facing the magnet assembly 22 is in a range of 40% to 70%; and / or, a third central angle 225 corresponding to the overlapping portion of the projection of the second magnet 222 and the stator core 11 to half of the second central angle 224 is in a range of 40% to 70%; and / or, the first central angle 223 and the third central angle 225 are the same. The center projection may refer to a projection of the first magnet 221 , the second magnet 222 and the stator core 11 with a point on the rotation axis of the rotor assembly 2 as the projection center when the rotor assembly 2 is in a balanced position.

[0065] In actual applications, the stator core 11 may also include a chamfered portion. If the stator core 11 includes a chamfered portion, the arc length of the inner arc of the stator core 11 facing the magnet assembly 22 may include the chamfered portion of the stator core 11, or may not include the chamfered portion of the stator core 11. The specific situation can be set based on the actual structural requirements of the motor. Similarly, the second central angle 224 corresponding to the inner arc of the stator core 11 facing the magnet assembly 22 may include the chamfered portion of the stator core 11, or may not include the chamfered portion of the stator core 11. The specific situation can be set based on the actual structural requirements of the motor.

[0066] In the embodiments of this specification, by setting the ratio of the first central angle 223 to half of the second central angle 224 to a range of 40% to 70%, and the ratio of the third central angle 225 to half of the second central angle 224 to a range of 40% to 70%, the cogging torque can be reduced, so that the swing angle of the rotor assembly can be increased while the motor output torque remains essentially unchanged, thereby facilitating the satisfaction of different consumers' tooth cleaning needs. Furthermore, the vibration frequency of the motor can be reduced, thereby avoiding situations where high-frequency vibration causes users to experience prominent toothaches, sore teeth, and other sensations, and also avoiding situations where high-frequency vibration causes increased motor noise, thereby improving the user experience of using an oral cleaning device with such a motor.

[0067] Figure 5 This is a schematic diagram of the structure of the fourth center angle and the fifth center angle provided in the embodiment of this specification. Figure 5 As shown, in a plane perpendicular to the rotation axis of rotor assembly 2, the ratio of the fourth central angle 226 of the first magnet 221, corresponding to the outer arc of the stator core 11, to the second central angle 224 ranges from 60% to 85%. The ratio of the fifth central angle 227 of the second magnet 222, corresponding to the outer arc of the stator core 11, to the second central angle 224 ranges from 60% to 85%. By setting a reasonable ratio range for the central angle corresponding to the outer arc of a single magnet to the central angle corresponding to the inner arc of the stator core, cogging torque can be reduced, the swing angle can be increased, and the vibration frequency of the motor can be lowered.

[0068] In practical applications, the cogging torque can be reduced and the swing angle can be increased by setting a reasonable ratio range of the arc length of the outer arc of a single magnet to the arc length of the inner arc of the stator core. Specifically, in a plane perpendicular to the rotation axis of the rotor assembly 2, the ratio of the arc length of the outer arc of the first magnet 221 facing the stator core 11 to the arc length of the inner arc of the stator core 11 facing the magnet assembly 22 is in a range of 60% to 70%; the ratio of the arc length of the outer arc of the second magnet 222 facing the stator core 11 to the arc length of the inner arc of the stator core 11 facing the magnet assembly 22 is in a range of 60% to 70%.

[0069] In the embodiments of this specification, in the plane containing the axis of rotation of the rotor assembly 2, at least one plane is a symmetry plane; the stator core 11 is arranged in a mirror-symmetrical manner with respect to the symmetry plane as a reference plane, and / or the first magnet 221 and the second magnet 222 are arranged in a mirror-symmetrical manner with respect to the symmetry plane as a reference plane. When in a balanced position, the symmetry plane used for the symmetry of the stator core 11 is the same as the symmetry plane used for the symmetry of the first magnet 221 and the second magnet 222. By symmetrically arranging the stator core and the magnets, the magnetic field distribution can be made more uniform, which is beneficial to the normal operation of the motor.

[0070] As another embodiment, the ratio of the first central angle 223 to the fourth central angle 226 can range from 30% to 45%, and the ratio of the third central angle 225 to the fifth central angle 227 can range from 30% to 45%. Preferably, the ratio of the first central angle 223 to the fourth central angle 226 can be further set to range from 35% to 40%, and the ratio of the third central angle 225 to the fifth central angle 227 can be further set to range from 35% to 40%. Specifically, the ratio range can be set to values ​​such as 35%, 37%, and 40% to improve the fit between the stator core and the magnet assembly.

[0071] Figure 6 This is a schematic diagram of the structure of the first angle provided in the embodiment of this specification. Figure 6 As shown, within a plane perpendicular to the rotation axis of the rotor assembly 2, a first angle 228 between the centerline of the first magnet 221 and the centerline of the second magnet 222 ranges from 73° to 87°. The centerline of the first magnet 221 is a line extending from the center of the first magnet 221 to the rotation axis, and the centerline of the second magnet 222 is a line extending from the center of the second magnet 222 to the rotation axis. The rotation axis can be the centerline of the power shaft 21, which, as will be understood, is also the centerline of the output shaft 212. The centerline of the first magnet 221 can be perpendicular to the rotation axis; the centerline of the second magnet 222 can also be perpendicular to the rotation axis. The first angle 228 can range from 73° to 87°. Specifically, the first angle 228 can be set to 75°, 79°, 83°, 85°, etc. In practical applications, the size of the first angle 228 can be adjusted based on actual needs and is not specifically limited here.

[0072] Figure 7 This is a schematic diagram of the structure of the second angle and the third angle provided in the embodiment of this specification. Figure 7 As shown, the first magnet 221 and the second magnet 222 are arranged at a preset central angle spacing around the circumference of the power shaft 21; wherein the preset central angle is a second angle 229. The second angle 229 can range from 23.5° to 38°. Preferably, the second angle 229 is specifically 28.5°. It can be understood that when constructing the rotor assembly 2, the spacing between the first magnet 221 and the second magnet 222 can be reasonably set so as to make the magnetic field generated by the magnet assembly 22 more uniform, thereby reducing the cogging torque, increasing the swing angle, and reducing the vibration frequency of the motor.

[0073] Specifically, two stator cores 11 can be provided, and the two stator cores 11 can be configured to be symmetrically distributed; two magnet assemblies 22 can be provided; each magnet assembly 22 can correspond to one stator core 11; and the third angle 230 between the two magnet assemblies 22 is greater than the second angle 229 between the first magnet 221 and the second magnet 222 in the magnet assembly 22. This allows each stator core 11 and each magnet assembly 22 to cooperate with each other, avoiding any abnormal impact on adjacent magnet assemblies 22, which could cause the motor to malfunction.

[0074] Figure 8 This is a schematic diagram of the structure of the first magnet provided in the embodiment of this specification. Figure 8 As shown, the first magnet 221 is in the shape of an arc and may include an outer arc 2211 and an inner arc 2212 distributed in the radial direction, and two side edges 2213 respectively connecting the corresponding ends of the outer arc 2211 and the inner arc 2212, and the angles of the center angles corresponding to the outer arc 2211 and the inner arc 2212 are the same. The structure of the second magnet 222 is consistent with that of the first magnet 221 and is also in the shape of an arc. The center angle corresponding to the outer arc 2211 may be the angle between the two first line segments formed by the two end points of the outer arc 2211 and the center of the power shaft 21 respectively connected. The center angle corresponding to the inner arc 2212 may be the angle between the two second line segments formed by the two end points of the inner arc 2212 and the center of the power shaft 21 respectively connected. It is understandable that the two first line segments and the two side edges 2213 may have overlapping portions, and the two second line segments and the two side edges 2213 may also have overlapping portions. The arc-shaped magnet shape can better match the shape of the air gap between the rotor assembly 2 and the stator assembly 1, which helps to generate a more uniform magnetic field distribution, thereby reducing vibration and noise caused by uneven magnetic field.

[0075] In the actual process of constructing the motor, the width range of the air gap 4 between the outer arcs of the first magnet 221 and the second magnet 222 and the inner arc of the stator core 11 facing the magnet assembly 22 can be set to 0.15 mm to 0.25 mm, so as to improve the fit between the rotor assembly 2 and the stator assembly 1 without affecting the normal operation of the rotor assembly 2.

[0076] In the embodiment of this specification, the thickness of the first magnet 221 and the second magnet 222 can be set within a preset thickness range, wherein the preset thickness range can be 1 mm to 2 mm; the thickness of the first magnet 221 and the second magnet 222 can be the distance in the radial direction between the outer arc 2211 and the inner arc 2212. It is understandable that the distance in the radial direction between the outer arc 2211 and the inner arc 2212 can represent the shortest distance between the outer arc 2211 and the inner arc 2212. Preferably, the thickness of the first magnet 221 and the second magnet 222 can be constructed to be 1.5 mm. In practical applications, the first magnet 221 and the second magnet 222 can also be constructed to be 1.2 mm, 1.8 mm, etc. The thickness of the first magnet 221 and the second magnet 222 can be determined based on the spatial distance between the power shaft 21 and the stator assembly 1. An appropriate magnet thickness can be selected to ensure that the magnets have a certain gap with the stator assembly after being arranged on the power shaft, while also ensuring that the magnetic field generated by the magnets meets the preset requirements, thereby reducing the cogging torque, increasing the swing angle, and reducing the frequency without affecting the rotation of the rotor assembly 2.

[0077] In the embodiments of this specification, the motor may further include a motor housing 3; the stator assembly 1 may be integrally injection-molded and embedded on both sides of the motor housing 3; the rotor assembly 2 may be installed within the motor housing 3, and the stator assembly 1 and the rotor assembly 2 may be coaxially adapted. The stator assembly 1 does not require manual secondary assembly, and the concentricity tolerance between the stator assembly 1 and the rotor assembly 2 can be small, effectively reducing the cumulative tolerance of the assembled motor, reducing the vibration generated by the rotor assembly 2 during rotation, and reducing the noise during motor operation.

[0078] In practical applications, the stator core 11 can be made of high-permeability silicon steel sheets. Silicon steel sheets are an alloy material primarily composed of silicon, carbon, and iron, and possess excellent magnetic permeability and corrosion resistance. In addition to silicon steel sheets, the stator core 11 can also be made of aluminum alloys, copper-nickel alloys, and other materials.

[0079] like Figure 1 As shown, a limit member 31 can also be provided on the motor housing 3. The limit member 31 can be used to prevent the rotor assembly 2 from rotating beyond a preset angle threshold, thereby ensuring the normal use of the motor and avoiding the situation where the motor cannot operate normally due to excessive rotation of the rotor assembly 2.

[0080] In the embodiments of this specification, the motor housing 3 may not be provided with the limit member 31, so that the rotatable angle of the rotor assembly 2 under the action of an external force can be greater than 360°, that is, the rotatable angle of the rotor assembly 2 under the action of an external force can be any value. When the external force is removed, the rotor assembly 2 can be reset to the equilibrium position under the action of the cogging torque. Specifically, the equilibrium position to which the rotor assembly 2 is reset can be determined based on the angle between the current non-equilibrium position and the first equilibrium position and the second equilibrium position. For example, when the external force is removed, the rotor assembly 2 can be reset toward the first equilibrium position or the second equilibrium position with the minimum angle.

[0081] In the embodiments of this specification, when the stator assembly 1 is in a non-powered state, the rotor assembly 2 may have a balanced position that cooperates with the stator core 11. The rotor assembly 2 may be in a balanced position when not subjected to external force; the balanced position may be a position where the rotor assembly 2 is in a stationary state relative to the stator assembly 1; the balanced position may ensure the normal starting of the motor. In practical applications, the number of balanced positions corresponds to the number of stator cores 11. For example, when the stator assembly 1 includes only a pair of stator cores 11, the rotor assembly 2 may include two balanced positions, namely a first balanced position and a second balanced position. Here, the two stator cores 11 in a pair of stator cores 11 may be mirror-symmetrical, and the first angle between the first balanced position and the second balanced position may be in the range of 180°-3° to 180°+3°.

[0082] In the embodiments of this specification, if no stopper is provided on the motor housing, the rotor assembly 2 can rotate to any angle under the action of an external force, allowing the user to manually rotate the brush head to any desired equilibrium position, or to the vicinity of any desired equilibrium position, as needed. For example, in an oral cleaning device where the brush filament area and the electronic display area on the brush head are located on the same side. It is understood that at this point, the rotor assembly 2 is located at one of the equilibrium positions. When the user needs to view prompt information displayed in the electronic display area through a mirror to avoid having to stop brushing to view the relevant prompt information, the user can manually rotate the brush head 180°, so that the brush filament area and the electronic display area face different sides, thereby allowing the user to view the prompt information displayed in the electronic display area through the mirror without affecting the user's brushing process, meeting the user's needs and improving the user's convenience in using the oral cleaning device. It is understood that after the user manually rotates the brush head 180°, the rotor assembly 2 is located at another equilibrium position.

[0083] like Figure 1 and Figure 2As shown, the motor may also include an electromagnetic coil 5 disposed around a stator core 11. In response to a control signal applied to the electromagnetic coil 5, the stator core 11 can rotate the rotor assembly 2 relative to the stator core 11 about the rotation axis. Furthermore, the stator core 11 can cause the rotor assembly 2 to rotate unidirectionally about the rotation axis relative to the stator core 11 within an angle range of 0° to 20°. Correspondingly, the stator core 11 can cause the rotor assembly 2 to rotate bidirectionally about the rotation axis relative to the stator core 11 within an angle range of 0° to 40°. This increases the swing angle and helps meet the dental cleaning needs of different consumers. The motor's operating frequency range is 100 Hz to 180 Hz; it can further maintain a stable operating frequency between 140 Hz and 150 Hz. This reduces the motor's vibration frequency, preventing users from experiencing prominent toothaches and soreness caused by high-frequency vibrations. It also prevents increased motor noise caused by high-frequency vibrations, thereby improving the user experience of oral cleaning devices equipped with this motor.

[0084] Figure 9 This is a schematic diagram of the structure of the power shaft provided in the embodiment of this specification. Figure 9 As shown, the power shaft 21 may include a rotor core 211 and an output shaft 212 disposed at the center of the rotor core 211. The output shaft 212 may be connected to a brush head of an oral cleaning device, thereby driving the brush head. The rotor core 211 also includes a mounting slot 2111 for mounting the magnet assembly 22.

[0085] In practical applications, the magnets in the magnet assembly 22 can be embedded in the mounting grooves 2111 using an adhesive, such as glue. Alternatively, the magnets in the magnet assembly 22 can be placed in the mounting grooves 2111 by welding. The first magnet 221 and the second magnet 222 in the magnet assembly 22 can be embedded in different mounting grooves 2111, respectively, thereby fixing the magnets in the magnet assembly 22 in the mounting grooves 2111 and preventing the magnet assembly 22 from falling out of the mounting grooves 2111 and affecting the normal operation of the motor.

[0086] In the embodiment of this specification, the number of corresponding mounting slots 2111 can be set based on the number of magnet assemblies 22. Preferably, the number of magnet assemblies 22 can be 2 groups, and accordingly, the number of mounting slots 2111 can be 4. The groove depth of the mounting slot 2111 can be set to 0.7 mm; the distance between the bottom of the mounting slot 2111 and the rotation axis can be set to 2.5 mm; the distance between the outer arc 2211 of the magnet in the magnet assembly 22 and the rotation axis corresponds to 4 mm; it can be understood that the magnet in the magnet assembly 22 is partially exposed outside the mounting slot 2111 to enhance the fit between the rotor assembly 2 and the stator assembly 1.

[0087] In actual applications, the motor can be set in the oral cleaning device, and specifically can be connected to the brush head of the oral cleaning device through the output shaft 212, so that when the rotor assembly 2 reciprocates under the influence of the stator assembly 1, it can drive the brush head of the oral cleaning device to reciprocate, thereby cleaning the teeth at a larger angle, which is beneficial to improving the cleaning angle and the cleaning ability of the oral cleaning device.

[0088] Figure 10 Schematic diagram of the distribution of simulation data of the motor cogging torque in the embodiment of this specification. Figure 11 Schematic diagram of the distribution of simulation data of motor torque in the embodiment of this specification. Figure 10 and Figure 11 The parameters of the test samples are as follows:

[0089] Figure 10 mid-dash line and Figure 11 Scheme A represented by the dotted line in the figure; the central angle corresponding to the first magnet and the second magnet in the magnet assembly is 49.5°, that is, the central angle corresponding to the outer arc and the inner arc of the first magnet and the second magnet are both 49.5°; the second angle of the interval between the first magnet and the second magnet is 28.5°; the magnet thickness is constructed to be 1.5 mm; the mounting groove depth is constructed to be 0.7 mm; the third angle between the two magnet assemblies is constructed to be 52.5°.

[0090] Figure 10 Solid middle line and Figure 11 In scheme B represented by the solid line in the figure, the central angle corresponding to the first magnet and the second magnet in the magnet assembly is 45°, that is, the central angle corresponding to the outer arc and the inner arc of the first magnet and the second magnet are both 45°; the second angle of the interval between the first magnet and the second magnet is 37°; the magnet thickness is constructed to be 1.5 mm; the mounting groove depth is constructed to be 0.7 mm; and the third angle between the two magnet assemblies is constructed to be 53°.

[0091] Figure 10 The dashed line and Figure 11 In scheme C represented by the dotted line, the central angle corresponding to the first magnet and the second magnet in the magnet assembly is 54°, that is, the central angle corresponding to the outer arc and the inner arc of the first magnet and the second magnet are both 54°; the second angle of the interval between the first magnet and the second magnet is 28°; the magnet thickness is constructed to be 1.5 mm; the mounting groove depth is constructed to be 0.7 mm; the third angle between the two magnet assemblies is constructed to be 44°.

[0092] It is understandable that as the rotation angle of the rotor assembly in the motor changes, the cogging torque of the motor will also change. Figure 10 Used to show the relationship between the cogging torque of an electric machine and the rotor components in the machine. Figure 10The horizontal axis in the figure can represent the rotation angle of the rotor assembly in the motor; the vertical axis can represent the cogging torque corresponding to the rotation angle of the rotor assembly.

[0093] For motors used in oral cleaning devices such as electric toothbrushes, the electromagnetic torque and cogging torque act in opposition to each other during the motor's swing. By reducing the cogging torque, the swing angle can be increased under the same electromagnetic torque, while the resonance frequency can be shifted downward. Figure 11 This is the experimental data obtained under a load of 0.5A forward current. The horizontal axis is the rotation angle of the rotor assembly; the vertical axis is the motor torque. Figure 11 Schematic diagram of the distribution of motor torque simulation data, Figure 10 It can be seen from the distribution diagram of the illustrated cogging torque simulation data that the zero-position torque of Scheme A is 9.03mN.m, and the NR position is 8.04°; the zero-position torque of Scheme B is 8.23mN.m, and the NR position is 9.71°; the zero-position torque of Scheme C is 9.6mN.m, and the NR position is 9.16°; based on this, the zero-position torque of the motor in the embodiment of this specification is low. This is because the modified electromagnetic structure greatly reduces the cogging torque, and also has a certain impact on the starting torque at the equilibrium position. The NR position angle increases, that is, the position angle where the electromagnetic torque and the cogging torque offset each other to 0, which is conducive to a larger swing angle and a downward shift of the resonant frequency.

[0094] In the embodiment of this specification, when the motor is in a no-load state of I=0A, the rotor is stationary at zero position and there is no output torque. When a positive current is applied, the rotor assembly generates a zero-position torque in the negative direction and rotates in this direction until it reaches the position where the natural return NR output torque is equal to 0Nm, and then shifts to the positive direction. Afterwards, if the current is positive, the rotor assembly will rotate backward around the NR position and stop at the preset NR position. If a negative current is applied, the direction of rotation of the rotor assembly can be opposite to the direction of rotation when a positive current is applied, thereby applying an alternating current to cause the rotor assembly in the motor to reciprocate.

[0095] For ease of description, spatially relative terms such as "above," "above," "on the upper surface of," and "upper" may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in a drawing is inverted, a device described as "above" or "on top of" another device or structure would then be positioned as "below" or "beneath" the other device or structure. Thus, the exemplary term "above" can include both the "above" and "below" orientations. The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used herein should be interpreted accordingly.

[0096] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0097] It should be noted that the terms "first", "second", etc. in the description and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0098] The foregoing is merely an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A motor, characterized in that: The motor comprises: a stator assembly arranged to generate a magnetic field, wherein the stator assembly comprises at least one stator core; a rotor assembly at least partially arranged within the magnetic field of the stator assembly, the rotor assembly comprising a power shaft and a magnet assembly disposed on the power shaft and cooperating with the stator core; each magnet assembly being configured to include a first magnet and a second magnet arranged circumferentially around the power shaft and cooperating with the same stator core, wherein at least a portion of the first magnet proximate to the stator core and at least a portion of the second magnet proximate to the stator core are configured to have different polarities; When in a balanced position, the first magnet and the second magnet correspond to two sides of the stator core respectively, and the first magnet overlaps with the central projection of the stator core in the radial direction, and the second magnet overlaps with the central projection of the stator core in the radial direction; The ratio of a first central angle corresponding to the overlapping portion of the projection of the first magnet and the stator core to half of a second central angle corresponding to the inner arc of the stator core facing the magnet assembly is in a range of 40% to 70%; and / or, The ratio of the third central angle corresponding to the overlapping portion of the projection of the second magnet and the stator core to half of the second central angle is in a range of 40% to 70%; and / or, The first central angle is the same as the third central angle.

2. The motor according to claim 1, characterized in that In a plane perpendicular to the rotation axis of the rotor assembly, the ratio of the fourth central angle corresponding to the outer circular arc of the first magnet facing the stator core to the second central angle ranges from 60% to 85%; the ratio of the fifth central angle corresponding to the outer circular arc of the second magnet facing the stator core to the second central angle ranges from 60% to 85%.

3. The motor according to claim 1, characterized in that In a plane perpendicular to the axis of rotation of the rotor assembly, the ratio of the arc length of the outer arc of the first magnet facing the stator core to the arc length of the inner arc of the stator core facing the magnet assembly is in a range of 60% to 70%; the ratio of the arc length of the outer arc of the second magnet facing the stator core to the arc length of the inner arc of the stator core facing the magnet assembly is in a range of 60% to 70%.

4. The motor according to claim 1, characterized in that Among the planes containing the rotation axis of the rotor assembly, at least one plane is a symmetry plane; The stator core is arranged in a mirror-symmetrical manner with the symmetry plane as a reference plane, and / or, The first magnet and the second magnet are arranged in mirror symmetry with the symmetry plane as a reference plane.

5. The motor according to claim 2, characterized in that The ratio of the first central angle to the fourth central angle ranges from 30% to 45%; the ratio of the third central angle to the fifth central angle ranges from 30% to 45%.

6. The motor according to claim 5, characterized in that The ratio of the first central angle to the fourth central angle ranges from 35% to 40%; the ratio of the third central angle to the fifth central angle ranges from 35% to 40%.

7. The motor according to claim 1, characterized in that In a plane perpendicular to the rotation axis of the rotor assembly, the first angle between the center line of the first magnet and the center line of the second magnet ranges from 73° to 87°; the center line of the first magnet is a line pointing from the center of the first magnet to the rotation axis, and the center line of the second magnet is a line pointing from the center of the second magnet to the rotation axis.

8. The motor according to claim 1, characterized in that The first magnet and the second magnet are both arc-shaped, including an outer arc and an inner arc distributed in the radial direction, and two side edges connecting the corresponding ends of the outer arc and the inner arc respectively; the central angles of the outer arc and the inner arc are the same.

9. The motor according to claim 8, characterized in that The width of the air gap between the outer arcs of the first magnet and the second magnet and the inner arc of the stator core facing the magnet assembly is in a range of 0.15 mm to 0.25 mm.

10. The motor according to claim 8, characterized in that The thickness of the first magnet and the second magnet are both within a preset thickness range; the preset thickness range is 1 mm to 2 mm; the thickness of the first magnet and the second magnet is the radial distance between the outer arc and the inner arc.

11. The motor according to claim 10, characterized in that The thickness of the first magnet and the second magnet are both 1.5 mm.

12. The motor according to claim 1, characterized in that The first magnet and the second magnet are arranged around the circumference of the power shaft at a preset central angle interval; the preset central angle is a second included angle.

13. The motor according to claim 12, characterized in that The second angle ranges from 23.5° to 38°.

14. The motor according to claim 13, characterized in that The second angle is 28.5°.

15. The motor according to claim 1, characterized in that The motor includes a motor housing; the rotor assembly is disposed in the motor housing.

16. The motor according to claim 15, characterized in that A limiter is provided on the motor housing; the limiter is used to prevent the rotor assembly from rotating beyond a preset angle threshold.

17. The motor according to claim 1, characterized in that The power shaft includes a rotor core and an output shaft.

18. The motor according to claim 1, characterized in that The power shaft includes a mounting groove; the mounting groove is used to install the magnet assembly.

19. The motor according to claim 18, characterized in that The number of the mounting slots is 4.

20. The motor according to claim 18, characterized in that The groove depth of the mounting groove is 0.7 mm.

21. The motor according to claim 18, characterized in that The magnets in the magnet assembly are embedded in the mounting grooves by adhesive.

22. The motor according to claim 1, characterized in that The electric machine includes electromagnetic coils disposed about the stator core that rotate the rotor assembly relative to the stator core about a rotational axis of the rotor assembly in response to control signals applied to the electromagnetic coils.

23. The motor according to claim 22, characterized in that The stator core enables the rotor assembly to rotate around the rotation axis in a unidirectional angle range of 0° to 20° relative to the stator core; the stator core enables the rotor assembly to rotate around the rotation axis in a bidirectional angle range of 0° to 40° relative to the stator core.

24. The motor according to any one of claims 1 to 23, characterized in that: There are two stator cores, and the two stator cores are constructed to be symmetrically distributed; there are two magnet assemblies; each magnet assembly corresponds to one stator core; the third angle between the two magnet assemblies is greater than the second angle between the first magnet and the second magnet in the magnet assembly.

25. The electric machine according to claim 1, characterized in that The frequency range of the motor in the operating state is 100 Hz to 180 Hz.

26. The motor according to claim 25, characterized in that The frequency range of the motor in the operating state is 140 Hz to 150 Hz.

27. An oral cleaning device, characterized in that The oral cleaning device comprises the motor according to any one of claims 1-26.

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