Motor for personal care devices

Abstract

According to one aspect, a motor 1 for a personal care device 10 is provided. The motor 1 includes a stator 2 having a stator face, a rotor 3 having a rotor face disposed opposite the stator face, and a spacer 4 protruding between the stator face and the rotor face to define a minimum air gap between the stator 2 and the rotor 3. The spacer 4 is disposed on one of the rotor face and the stator face and has a contact surface configured to engage the other of the rotor face and the stator face.

Description

Technical Field

[0001] The present invention generally relates to a motor for personal care devices such as, for example, an electric toothbrush, an electric shaver, and a skin care device.

Background Art

[0002] The drive system of a personal care device is an electromagnetic module that creates the necessary movements of the device. In an electric toothbrush, the drive system creates the oscillating movement of the brush head. The drive system has a motor that includes a rotor and a stator. The rotor and the stator are separated by an air gap, which is important for the proper operation of the motor. When the air gap is closed, the frictional force between the rotor and the stator can prevent relative movement.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Therefore, in order to ensure the proper function of the motor, it is desirable to maintain and prevent the closing of the air gap.

[0004] Therefore, an object of the present invention is

Means for Solving the Problems

[0005] According to an embodiment of the first aspect, there is provided a motor for a personal care device, comprising: a stator having a stator surface; a rotor having a rotor surface disposed opposite to the stator surface; and a spacer protruding between the stator surface and the rotor surface and defining a minimum air gap between the stator and the rotor, wherein the spacer is disposed on one of the rotor surface and the stator surface and has a contact surface configured to engage with the other of the rotor surface and the stator surface.

[0006] In other words, a spacer is permanently placed between the rotor and stator to define the minimum air gap. The presence of a spacer between the rotor and stator prevents the rotor and stator from fitting together completely, thus preventing the air gap from closing. In other words, the spacer prevents the rotor surface and stator surface from directly contacting each other (at any point other than the spacer contact surface) and maintains the distance between the stator and rotor. Also, since the size of the spacer determines the (minimum) size of the air gap, the length of the protrusion can correspond to the desired air gap size. Therefore, a longer spacer (i.e., one that protrudes more from the rotor surface or stator surface) increases the distance between the stator and rotor and thus results in a larger air gap, while a spacer with a shorter protrusion defines a smaller air gap.

[0007] The rotor and stator are arranged adjacent to each other, with each having a surface at the interface facing the other surface, i.e., the stator surface faces the rotor surface. Spacers are placed on either the stator surface or the rotor surface, and therefore the minimum air gap may be defined more specifically between these surfaces. When spacers are placed on or in the stator surface, the contact surface of the spacer is configured to contact the rotor surface such that contact occurs between the rotor surface and the contact surface, and the rotor abuts against the spacer. Conversely, when spacers are provided on the rotor surface, the contact surface of the spacer is configured to contact the stator surface of the stator, and the stator may abut against the contact surface of the spacer.

[0008] However, it is also possible to ensure that there is no contact between the contact surface of the spacer and the stator surface or rotor surface, and that the spacer is positioned on one of the rotor surface and stator surface, and is separated from the other surface. This separation may be, for example, in the range of 0.1 mm to 5 mm. Therefore, the contact surface may be configured, fitted, or capable of engaging (i.e., contacting) the rotor surface or stator surface, but in practice it does not have to engage or contact the rotor surface or stator surface.

[0009] Therefore, according to embodiments of the present invention, the minimum air gap is clearly defined by the motor components (i.e., spacers), and the calibration / setting of the air gap is integrated into the device. The air gap is automatically set to an appropriate minimum size and maintained by the spacer for the life of the drive system. The spacer corresponds to the minimum air gap between the rotor and stator, but the spacer does not determine the maximum air gap. That is, since a separation or gap may be provided between the distal end of the spacer and the rotor or stator surface to which the spacer is configured to engage or contact, the air gap may be greater than the length of the spacer's projection. Therefore, the air gap may be set to a desired distance, but it is understood that the spacer is provided as a "backup" to ensure that a minimum distance is always provided between the rotor and stator. The motor may be provided as part of the drive system.

[0010] The presence of a spacer, and the arrangement of the spacer between the stator and rotor, defines and maintains a minimum air gap. The spacer may be positioned on or in the stator or rotor surface at its proximal end, and the contact surface of the spacer may be considered to be in contact with the other stator or rotor surface at its distal end. The spacer may also be called a spacer element, projection, projection, protrusion, bearing, or bearing point. Since the spacer protrudes from the stator or rotor surface, it is clear that the surface area of ​​the contact surface of the spacer is smaller than the surface area of ​​the stator surface and the surface area of ​​the rotor surface, respectively. More than one spacer may be provided, each of which is positioned on or in the rotor and stator surfaces, and each has a contact surface configured to engage (i.e., contact) the other rotor and stator surface.

[0011] The rotor and stator are arranged in a motor such that the rotor rotates at least partially relative to the stator, and the rotor rotates around a rotation axis. In a preferred embodiment, the spacer is aligned with the rotation axis of the rotor. That is, the spacer may preferably be positioned at the center of rotation of the rotor. Therefore, since the spacer contacts the center point of the rotor surface or stator surface, mutual friction between the spacer and the rotor surface or stator surface can be reduced.

[0012] The spacer is preferably formed, at least partially, from one or more of the following materials: wear-resistant material, material with a low coefficient of friction, and impact-resistant material. An example of such material is polyoxymethylene. At least the contact surface of the spacer is preferably formed from such material. This material can reduce friction between the spacer, specifically the contact surface of the spacer, and the rotor surface or stator surface, and can improve the durability and lifespan of the spacer. Similarly, a portion of the stator surface or rotor surface configured to engage with the spacer may be provided by or formed from a material that is wear-resistant, has a low coefficient of friction, and / or impact-resistant.

[0013] The spacer can take various forms. The spacer may be a rolling bearing that rotates at least partially relative to the rotor and stator. The rolling bearing may be held within a socket on the rotor or stator surface so that it can rotate freely within the socket. The surface of the rolling bearing protruding from the socket forms a contact surface. Since the rolling bearing moves freely relative to both the stator and rotor, friction between the rolling bearing and the surfaces of the rotor and stator can be reduced.

[0014] In a preferred embodiment, the spacer is formed on or connected to the stator such that the spacer protrudes from at least a portion of the stator surface. That is, the spacer is preferably positioned on or in the stator surface such that it protrudes from the stator surface and engages (i.e., contacts) with the rotor surface at its contact surface. The spacer may be attached to or incorporated into the stator in any suitable manner, examples of which are described in the detailed description.

[0015] The stator surface may be configured to receive a plate with spacers. That is, the plate with spacers may be attached to the stator surface by interconnection or fastening means between the plate and the stator surface. For example, the stator surface may have a recess configured to receive a spacer plate, and the recess may have crush ribs or snaps on its outer circumference for holding the spacer plate within the recess. Such an arrangement may allow for simpler manufacturing and assembly, and / or ensure secure attachment of the spacer to the stator surface. In an alternative configuration, the rotor surface may similarly be configured to receive a plate with spacers.

[0016] The stator may preferably have a core formed from a plurality of laminates, and the spacers may be projections extending from at least one end of the laminate of the core. That is, a laminate, such as an iron laminate, may be positioned within the stator such that the ends of the laminate provide at least a portion of the stator surface, and projections from one or more ends of the laminate may extend therefrom to provide spacers.

[0017] The stator may have one or more cores formed from a plurality of laminates, each core may have projections for providing one or more spacers. That is, the projections may extend from one or more ends of the laminate of each core (i.e., the projections may extend from each end of the core), thereby providing a plurality of spacer elements, and the distal end of each projection is configured to engage with the rotor surface. In this embodiment, it can be seen that each end of the core forms at least a portion of the stator surface. In a preferred embodiment, the stator has two cores.

[0018] If one or more ends of one or more cores provide at least a portion of the stator surface, it can be seen that one or more ends of one or more cores may be configured to receive a plate having a spacer. That is, the ends of the cores may be configured to receive a plate having a spacer. For example, the ends of the cores may be provided with stepped portions for receiving a spacer plate.

[0019] The stator may also have bobbins in which one or more cores are positioned and held. The ends of the bobbins may provide at least a portion of the stator surface so that spacers can be positioned or formed at the ends of the bobbins. The bobbins may consist of multiple parts, such as two complementary bobbin halves.

[0020] At least a portion of the rotor surface may have a low-friction coating. In addition to or alternatively, at least a portion of the stator surface may have a low-friction coating. Thus, mutual friction between the spacer and the stator surface or rotor surface can be reduced. Similarly, plates made of a low-friction and / or wear-resistant material may be provided on at least a portion of the rotor surface. Plates made of a low-friction and / or wear-resistant material may be provided on at least a portion of the stator surface.

[0021] In a preferred embodiment, the contact surface of the spacer is curved. That is, the distal end of the spacer is rounded, curved, or hemispherical in shape to provide a curved contact surface. This reduces the contact area between the spacer and the stator or rotor surface at the contact surface of the spacer, thereby minimizing friction.

[0022] A rotor surface is any surface of the rotor, or any surface of any part or component of the rotor, which is positioned opposite the stator. Similarly, a stator surface is any surface of the stator, or any surface of any part or component of the stator, which is positioned opposite the rotor. For example, either or each of the rotor and / or stator may have a plate or cover positioned at the interface between the rotor and the stator, such that the surface of the plate or cover provides the rotor surface and / or the stator surface. Furthermore, a rotor surface may consist of multiple surfaces of the rotor or components of the rotor. Similarly, a stator surface may consist of multiple surfaces of the stator or components of the stator. The stator surface is positioned opposite or facing the rotor surface.

[0023] The rotor may preferably have magnets having a magnetic surface that provides all or part of the rotor surface. That is, the rotor may be configured such that the magnets are positioned opposite / facing the stator such that the rotor surface is the magnetic surface. Similarly, the stator may consist of one or more iron cores, the ends of which may provide all or part of the stator surface.

[0024] According to an embodiment of the second aspect, a stator for use in a motor of a personal device is provided, the motor having a stator and a rotor, the stator having a stator surface that engages with a rotor surface of the rotor and a spacer protruding from the stator surface for defining a minimum air gap between the stator and the rotor.

[0025] Therefore, embodiments of the present invention are also applicable to a stator for a motor of a personal device and a motor having the stator. The features of the first aspect also apply to the second aspect, and vice versa.

[0026] According to an embodiment of the third aspect, a personal care device having a motor or a stator according to the above-described aspects of the present invention is provided. For example, the personal care device may be an oral care device such as an electric toothbrush or an electric shaver, or a skin care device such as a skin massager. Embodiments of the present invention can be applied to any series magnet-stator configuration. The motor may be provided as part of the drive system of such a device.

[0027] The present invention also extends to a method aspect corresponding to the device aspect.

[0028] In particular, according to an embodiment of the fourth aspect, a method of manufacturing a motor for a personal care device, the method comprising the steps of mounting a rotor having a rotor surface in the motor, and disposing a stator having a stator surface adjacent to the rotor in the motor, the rotor surface facing the stator surface, and a spacer disposed on one of the rotor surface and the stator surface protruding between the stator surface and the rotor surface to define a minimum air gap between the stator and the rotor, disposing the stator such that a contact surface of the spacer engages with the other of the rotor surface and the stator surface, moving the stator toward the rotor, and fixing the stator in the motor.

[0029] Therefore, the spacer determines and controls the minimum air gap between the rotor and the stator, and the stator is fixed to the motor at a position where a desired air gap is provided between the rotor and the stator. The means for setting the air gap is explicitly and permanently present in the product itself. No additional parts such as shims are required, nor is a shimming procedure. Therefore, the complexity and cost of assembly can be reduced.

[0030] The stator may be moved towards the rotor by the magnetic force provided between the rotor and the stator. The stator may be fixed in place using any suitable fixing means, such as screws or bolts.

[0031] Therefore, it can be seen that embodiments of the present invention may provide means for setting the minimum air gap between the rotor and the stator, and means for controlling the air gap during the life of the motor. As described above, the manufacturing method according to embodiments of the present invention may eliminate the requirement for a shimming procedure during manufacturing, thereby reducing the complexity and cost of manufacturing.

[0032] Embodiments of the present disclosure may take the form of various components and arrangements of components, as well as various steps and arrangements of steps. Therefore, the drawings are for the purpose of illustrating various embodiments and should not be construed as limiting the embodiments. In the drawings, like reference numerals refer to like elements. Further, note that the figures may not be drawn to scale.

Brief Description of the Drawings

[0033] [Figure 1] It is a diagram of an example of the motor discussed above. [Figure 2] It is a diagram of the shimming manufacturing process discussed above. [Figure 3] It is a block diagram of a personal care device according to a general embodiment of one aspect of the present invention. [Figure 4] It is a diagram of an electric toothbrush to which embodiments of the aspect of the present invention may be applied. [Figure 5(A)] This is a diagram of a motor according to a general embodiment of one aspect of the present invention. [Figure 5(B)] This is a diagram of a motor according to a general embodiment of one aspect of the present invention. [Figure 6] This is a diagram of a manufacturing method according to a general embodiment of another aspect of the present invention. [Figure 7] This is a side view of a drive system having a motor according to one embodiment of the present invention. [Figure 8] Figure 7 is a top view of the drive system. [Figure 9] This is a perspective view of a stator according to an embodiment of one aspect of the present invention. [Figure 10] This is a perspective view of a rotor according to one embodiment of the present invention. [Figure 11] This is an end view of a motor according to one embodiment of the present invention. [Figure 12] This is a side view of a motor according to an embodiment of one aspect of the present invention. [Figure 13] This is a side view of a motor according to an embodiment of one aspect of the present invention. [Figure 14] This is a top view of a motor according to one embodiment of the present invention. [Figure 15] This is a perspective view of a stator according to an embodiment of one aspect of the present invention. [Figure 16(A)] This is a perspective view of a stator according to an embodiment of one aspect of the present invention. [Figure 16(B)] Figure 16A shows a perspective view of the stator spacer element. [Figure 17(A)] This is a perspective view of a stator and spacer element according to an embodiment of one aspect of the present invention. [Figure 17(B)] A further diagram of the stator shown in Figure 17A is provided. [Figure 18(A)] This is a perspective view of a stator according to an embodiment of one aspect of the present invention. [Figure 18(B)] Figure 18A is a perspective view of the stator spacer element. [Figure 18(C)] Figure 18A is a perspective view of the stator shown. [Figure 19(A)] This is a perspective view of a stator according to an embodiment of one aspect of the present invention. [Figure 19(B)] Figure 19A is a side view of the stator. [Figure 19(C)] Figure 19A is a perspective view of the stator. [Figure 20(A)] This is a perspective view of a stator according to an embodiment of one aspect of the present invention. [Figure 20(B)] Figure 20A is a perspective view of the stator spacer element. [Figure 20(C)] Figure 20A is a perspective view of the stator. [Figure 21(A)] This is a perspective view of a stator and spacer element according to an embodiment of one aspect of the present invention. [Figure 21(B)] Figure 21A is a side view of the stator. [Figure 21(C)] Figure 21A is a perspective view of the stator. [Figure 22(A)] This is a perspective view of a stator and spacer element according to an embodiment of one aspect of the present invention. [Figure 22(B)] Figure 22A is a perspective view of the stator. [Figure 23] This is a perspective view of a stator according to an embodiment of one aspect of the present invention. [Figure 24] This is a perspective view of a stator according to an embodiment of one aspect of the present invention. [Modes for carrying out the invention]

[0034] The embodiments of this disclosure, and their various features and advantageous details, are more adequately described by reference to non-limiting examples shown and / or illustrated in the drawings and described in detail in the following description. It should be noted that the features illustrated in the drawings are not necessarily drawn to a fixed scale, and that features of one embodiment may be adopted together with others, as will be recognized by those skilled in the art, even if not explicitly stated herein. Descriptions of well-known components and processing techniques may be omitted so as not to unnecessarily obscure the embodiments of this disclosure. The embodiments used herein are intended merely to facilitate understanding of how the embodiments of this disclosure may be carried out and to enable those skilled in the art to carry them out further. Accordingly, the embodiments described herein should not be construed as limiting the scope of the embodiments of this disclosure as defined solely by the appended claims and applicable law.

[0035] The embodiments described herein are not limited to the specific methods, protocols, apparatus, devices, materials, and applications described herein, and it should be understood that these may be modified. Furthermore, the terms used herein are intended to describe only specific embodiments and are not intended to limit the scope of the claimed embodiments. It should be noted that, as used herein and in the appended claims, the singular forms “a, an” and “the” include plural references unless the context explicitly indicates otherwise.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by a person of ordinary skill in the art to which the embodiments of this disclosure belong. Preferred methods, apparatus, and materials are described herein, but any methods and materials similar or equivalent to those described herein may be used in carrying out or testing the embodiments of this disclosure.

[0037] Figure 1 shows an example of a typical configuration of a motor 1 used in a drive system. The motor has a stator 92 and a rotor 93 separated by an air gap 95. In this configuration, the stator 92 is formed by two iron core coils 921 and 922, and the rotor 93 is formed by a magnet 931 and a back iron 932. The interaction between the magnetic field from the stator 92 and the magnetic field from the rotor 93 generates a torque in the Y direction. This torque causes the rotor 93 to move around the y-axis.

[0038] The air gap of 95 separates the stator and rotor, and the air gap is necessary for the proper functioning of the motor. If the air gap is closed so that δ=0, the relative motion between the rotor and stator can be hindered by the frictional force between them. Therefore, the presence of an air gap in the motor is important.

[0039] Furthermore, the air gap can be used to alter the performance and efficiency of a motor. A larger air gap reduces the interaction between the stator's magnetic field and the rotor's magnetic field, decreasing the effective torque generated in the rotor. A smaller air gap increases the interaction between the stator's and rotor's magnetic fields, increasing the effective torque generated in the rotor. Therefore, setting and maintaining a specific air gap distance is crucial for achieving the desired motor operation.

[0040] A common method currently used to set the air gap requires the use of shims in a process called "shimming," in which the shims precisely control the air gap during manufacturing. In this process, shims (strips of appropriate thickness) are placed between the rotor 93 and the stator 92 before the stator is fixed to the motor or drive frame. The stator slides towards the strips under the attractive force of magnets. The air gap is then set to the correct size by fixing the stator in place and removing the shims.

[0041] Figure 2 shows an example of such a process. In step (1), the rotor 93 is attached to the motor 1, and in step (2), a separate shim 94 is placed between the rotor 93 and the stator 92 to position the stator 92. In step (3), a magnetic force F attracts the stator 92 toward the rotor 93, and the stator 92 is fixed in place by a fixing point 923. Finally, in step (4), the shim 94 is removed, leaving an air gap 95.

[0042] The stator's core creates a certain attractive force between the rotor and stator, causing them to move toward each other, which can reduce or close the air gap. Therefore, to prevent movement of either component, both the stator and rotor must be properly fixed along the Y-axis. However, despite these measures, the air gap can still close, resulting in a complete loss of motor function. For example, air gap closure can be caused by one or more of the following: - Magnetic attraction force, - User load, and / or - Insufficient fastening of the stator or rotor due to the following: • Creep of plastic parts in the drivetrain, • Slippage at the screw connection, or • Dropping the part can lead to plastic deformation.

[0043] Therefore, in order to ensure the proper functioning of the motor, it is desirable to maintain and prevent the closure of the air gap.

[0044] Figure 3 is a block diagram of a personal care device according to a general embodiment of one aspect of the present invention. According to one embodiment of the present invention, the personal care device 10 has a motor 1. The personal care device 10 may be, for example, an oral care device such as an electric toothbrush, an oral care device such as an electric shaver, a skin care device such as a skin massager, or any other type of personal care device.

[0045] Figure 4 shows an exemplary personal care device in which the teachings of this disclosure may be implemented. The personal care device in Figure 4 is in the form of an electric toothbrush, but is not limited thereto, and it will be understood that the teachings of this disclosure may be implemented in other devices having a motor. For example, the teachings may be applied to personal care devices such as tongue cleaners, shavers, clippers or trimmers, hair removal devices, or skin care devices. The personal care device 10 has an attachment structure 116 and a handle portion 112. The handle portion has a motor 1. The handle portion 112 may include a drive system 120 and a drive shaft 7. The drive shaft 7 extends from the distal end f of the handle portion 112 and enters the attachment structure 116 when the attachment structure 16 is attached to the handle portion 112.

[0046] Motor 1 may have a motor controller (i.e., control electronic circuit), which may be any suitable controller, microcontroller, processor, power supply and / or other electronic device, or a combination thereof, for providing power and control signals to perform various functions, as will be further discussed below.

[0047] In the embodiment, the motor 1 may be configured to provide and control the operation of the drive system 120 for generating mechanical stimulation. The mechanical stimulation may have vibration or other motion at high frequencies, for example, frequencies greater than 50 Hz, for example, in the range of 250 to 300 Hz. The motor 1 may be a motor according to an embodiment of the present invention.

[0048] Referring further to Figure 4, the distal end of the attachment structure 116 includes the brush head 118. However, it can be understood that different types of attachment structures and devices may be used with different types of personal care devices 10 than the electric toothbrush shown in the example of Figure 4.

[0049] During operation, the attachment structure 116 performs movement in response to the motor 1, which operates to control the movement of the drive train 120 in order to generate mechanical stimulation.

[0050] Figures 5A and 5B show alternative configurations according to a general embodiment of one aspect of the present invention. Both figures show a motor 1 having a stator 2 and a rotor 3, with a spacer 4 positioned between them to define a minimum air gap 5. In Figure 5A, motor 1a has a spacer 4a positioned on the stator surface and configured to engage (i.e., contact) with the surface of the rotor 3. Conversely, motor 1b in Figure 5B has a spacer 4b positioned on the rotor surface and configured to engage (i.e., contact) with the surface of the stator 2. Thus, in each configuration, the spacer 4 defines the minimum distance between the rotor 3 and the stator 2 corresponding to a desired air gap. The defined air gap 5 is maintained by the spacer 4 such that the minimum size of the air gap 5 is determined by the size of the spacer 4 in the Y direction.

[0051] The contact surface of the spacer 4 is configured to engage with or contact the rotor surface or the stator surface. However, the contact surface of the spacer may be configured not to contact the stator surface or rotor surface, such that the spacer 4 is positioned on one of the rotor surface and the stator surface and spaced apart from the other of the rotor surface and the stator surface. For example, the spacer may be positioned on the stator surface and configured to engage with the rotor surface, but in reality it may not engage with or contact the rotor surface, and a gap may be provided between the spacer and the rotor. Similarly, the spacer may be positioned on the rotor surface and configured to engage with the stator surface, but in reality it may not engage with or contact the stator surface, and a gap may be provided between the spacer and the stator. Therefore, the spacer is still provided to prevent the closure of the air gap, but since it does not initially contact the rotor surface or the stator surface, it can be considered a "backup" in the event that the rotor and stator move toward each other, for example, due to a failure / creep of a component or fixture, or an impact on the motor, for example, due to the dropping of the equipment.

[0052] Figure 6 shows a method for manufacturing a motor according to a general embodiment of one aspect of the present invention. As shown in step (1), a rotor 3 is attached to the motor. In step (2), a stator 2 is placed inside the motor. Due to the magnetic force F between the rotor 3 and the stator 2, the stator 2 and the rotor 3 are attracted to each other at the interface region where a spacer 4a is placed between the stator 2 and the rotor 3. Therefore, the spacer 4a prevents the stator 2 and the rotor 3 from directly contacting each other at points other than the contact region of the spacer 4a. In step (3), the stator 2 is fixed in a predetermined position in the motor at a fixing point 41. Any suitable fixing means, such as screws or bolts, can be used. It will be apparent from this method of manufacture that a means for setting an air gap is clearly present in the motor itself and is provided by the spacer.

[0053] In the configuration shown in Figure 6, spacer 4a is located on the stator 2. However, as discussed above with reference to Figure 5B, the spacer may alternatively be located on the rotor 3. The method of manufacturing the motor is the same in both configurations.

[0054] Figure 7 is a side view of a drive system having a motor according to an embodiment of one aspect of the present invention. The drive system includes an output shaft 7 and a motor 1, which includes a rotor 3, a stator 2, and a spacer 4 positioned between the rotor 3 and the stator 2 to define a minimum air gap 5. The drive system may have further elements that are not necessary to understand the embodiment of the present invention and are therefore not shown in the figure.

[0055] In this embodiment, the rotor 3's axis of rotation 6, around which the rotor 3 can rotate, is aligned with the spacer 4. The output shaft 7 of the drive system is also aligned with the axis of rotation 6. This is also shown in Figure 8, which is a top view of the drive system shown in Figure 7. Aligning the spacer's protrusion 4 with the axis of rotation 6 minimizes the contact area between the spacer's protrusion 4 and the surface of the rotor 3 or stator 2, and also reduces friction between the spacer's protrusion 4 and the surface of the rotor 3 or stator 2.

[0056] Figure 9 is a perspective view of a stator 2 according to an embodiment of one aspect of the present invention. The stator 2 may also be the stator 2 shown in the drive system of Figures 7 and 8. The stator 2 has two iron cores having a plurality of laminates 8. Windings are provided around each core to provide two coils. Spacers 4a are positioned on the stator surface 22 so as to protrude from the stator surface 22. The ends of the laminates 8 may also protrude from the end face of the stator, but the amount of protrusion of the ends of the laminates is not as large as the amount of protrusion of the spacers 4a so as not to contact the rotor 3 (i.e., the laminates do not protrude much from the stator surface, and the spacers 4a protrude even more). The air gap is generally defined as the distance between the stator and the rotor. If the stator has laminates and the ends of these laminates protrude from the end face of the stator, the air gap may also be defined as the distance between the ends of the laminates and the rotor (e.g., the magnets of the rotor), i.e., the air gap is the shortest distance between the components of the stator and the components of the rotor (excluding the spacers).

[0057] Spacer 4a has a circular upper shape at its contact surface to minimize the contact area between the spacer and the rotor. Furthermore, spacer 4a may be made of a wear-resistant material with a low coefficient of friction to further reduce friction between spacer 4a and the rotor surface. The operating principle of the drive system is not affected by the presence of spacer 4a.

[0058] In this embodiment, the stator surface 22 is the end of the stator body, which may be a bobbin holding two cores, and the spacer 4a is formed at the end of the bobbin. However, as will become clear from the example configuration described later, the stator surface may change depending on the stator configuration, and the formation or position of the spacer may also change.

[0059] Figure 10 is a perspective view of a rotor 3 according to an embodiment of one aspect of the present invention. The rotor 3 may also be the rotor 3 shown in the drive system in Figures 7 and 8. The rotor 3 has a magnet 31, and the output shaft 7 of the drive system is connected to the rotor 3. The rotor 3 and the output shaft 7 rotate around a rotation axis 6, and the rotation axis 6 extends along the length of the output shaft 7. In this embodiment, a rotor surface 32 is provided as the surface of the magnet 31, and no spacers are placed on the rotor surface. Therefore, the spacers are placed on the stator surface, and the contact surface of the spacers engages with and contacts the rotor surface 32 (the surface of the magnet 31). Preferably, the spacers may contact the rotor surface 32 at a center point aligned with the rotation axis 6 of the rotor 3 so that the spacers coincide with the rotation axis.

[0060] Figure 11 is an end view of a motor 1 according to an embodiment of one aspect of the present invention. The motor may be the motor shown in Figures 7 and 8, and may utilize the stator shown in Figure 9 and the rotor shown in Figure 10. The end of the laminate 8 is shown on either side of the rotating shaft 6, and the magnets 32 of the rotor have a north pole and a south pole.

[0061] Figure 12 is a side view of a motor according to an embodiment of one aspect of the present invention. In this embodiment, the spacer 4b is positioned on the rotor 3 and configured to engage with the stator 2. The rotor 3 may be equipped with magnets, and the spacer 4b may be positioned on the surface of the magnets that provide the rotor surface.

[0062] Figures 13 and 14 show another embodiment in which the spacer 4b is provided on the rotor surface of the rotor 3. It can be seen that the spacer is aligned with the rotation axis of the rotor 3.

[0063] Figure 15 is a perspective view of the configuration of a stator according to an embodiment of one aspect of the present invention. The stator 2 has a rolling bearing 41a disposed on the stator surface 22 of the stator 2. The rolling bearing 41a provides a spacer such that the surface of the rolling bearing 41a is a contact surface configured to engage with the rotor surface, for example, the surface of a magnet. The rolling bearing 41a is disposed within a collar or socket of the stator 2. The rolling bearing 41a is seated within the collar / socket and rotates freely relative to the stator 2 and the rotor. Therefore, friction between the rolling bearing 41a and the stator 2 and the rotor can be reduced.

[0064] Figures 16A and 16B show perspective views of a stator configuration according to an embodiment of one aspect of the present invention. In this configuration, the spacer 42a is provided on a plate configured to connect to the stator surface 22 of the stator 2, more specifically, to the end of the laminate 8 of the stator 2. That is, the plate having the spacer 42a is directly attached to the laminate end 8. In this configuration, the stator surface 22 can be considered to have the laminate end 8 and the body of the stator 2 (e.g., the bobbin). The spacer 42a can be considered a bearing positioned in the center of the plate, configured to engage with the laminate end 8. The plate may be attached to the stator using any suitable fastening means, such as adhesive. Such an arrangement is easy to manufacture, easy to test, and requires no modification of tools when applied to existing motor designs. The ends of the laminate may protrude slightly from the stator body to mount the plate, but the amount of protrusion should not be as large as the amount of spacer 42a protruding from the plate. The plate may be a non-pressed iron (e.g., brass) portion positioned on the end face of the laminate, which allows for tight tolerance control in the Y direction. The plate may simply act as a supported beam, bridging the stator body between the ends of the laminate, across both ends of the laminate, so as not to contact the stator body. The material of the plate must be stiff enough to support thrust loads without deformation. Spacer 42a (bearing point) protrudes slightly from the laminate surface.

[0065] Figures 17A and 17B show the configuration of a stator and spacer element according to an embodiment of one aspect of the present invention. In this configuration, the spacer 43a is provided on the stator surface 22, more specifically on a plate configured to connect to a recess provided in the stator body. That is, the stator surface 22 is shaped to receive and hold the plate having the spacer 43a. The plate may be held in the recess by crush ribs or snaps 24 arranged on the outer edge of the recess. The recess has stepped portions 81 at each of the laminate ends 8 where the plate is located when held in the recess. In this configuration, the stator surface 22 may appear to be composed of the body of the stator 2 (e.g., a bobbin) and the stepped end of the laminate 81.

[0066] Such an arrangement is easy to manufacture, reliable, resilient, and provides good tolerances. Each stepped portion 81 at the end of the laminate provides tight tolerance control. The plate may be a non-pressed iron (e.g., brass) portion placed on the stepped portion 81, enabling tight tolerance control in the Y direction. Also, the spacer 43a (bearing point) protrudes slightly from the laminate surface. In Figure 17B, Figure (3), the end of the laminate 8 protrudes above the horizontal plane of the stator body, and the spacer 43a protrudes significantly above the surface. Crush ribs or snaps are added to the recesses to hold the plate, minimizing vibration and noise.

[0067] Figures 18A to 18C are perspective views of a stator configuration according to an embodiment of one aspect of the present invention. In this configuration, the spacer 44a is provided as a portion held at the end of the stator body by a collar. As can be seen from Figure 18A, the stator surface 22 is shaped to receive and hold the spacer portion 44a. The spacer portion 44a is shaped to engage with the stator surface 22 so that the spacer portion 44a is held within the stator 2. Each end of the laminate 8 is provided with a stepped portion 81 for receiving the stator body, and a thick portion of the stator body surrounding the spacer portion 44a is realized so that the spacer portion 44a is securely held. In this configuration, the stator surface 22 can be considered as the body of the stator 2 (e.g., a bobbin).

[0068] Each stepped portion 81 at the end of the laminate provides tight tolerance control. The stator body (e.g., bobbin) engages with the stepped portion, enabling tight tolerance control in the Y direction. The spacer portion may be a threaded non-iron (e.g., brass) portion that provides a spacer (bearing point) and is assembled between the stator body, which may constitute two complementary bobbins (bobbin halves). The spacer 44a (bearing point) protrudes slightly from the laminate surface.

[0069] Figures 19A to 19C are perspective views of a stator configuration according to an embodiment of one aspect of the present invention. In this configuration, the spacer 45a is provided on the stator surface 22, and more specifically, is molded into the stator body. The stator body may be a bobbin, and the spacer 45a may be formed as part of the bobbin so as to protrude from the surface of the bobbin. In this configuration, the stator surface 22 can be seen as the surface of the stator body, i.e., the surface of the bobbin. Each end of the laminate 8 is provided with a stepped portion 81 for receiving the stator body, improving tolerances.

[0070] Since the spacer 45a is formed from the same material as the stator body (bobbin), a material suitable for the stator body is also used to provide the spacer 45a. This configuration is low-cost because it does not require additional parts. Each stepped portion 81 at the end of the laminate has tight tolerance control. The stator body (e.g., bobbin) engages with each stepped portion 81, enabling tight tolerance control in the Y direction. The spacer 45a is molded into the bobbin. The spacer 45a (bearing point) protrudes slightly from the laminate surface.

[0071] Figures 20A to 20C show the configuration of a stator according to an embodiment of one aspect of the present invention. In this configuration, the spacer 46a is provided on a strap configured to connect to a recess provided on the stator surface 22, more specifically on the stator body. That is, the stator surface 22 is shaped to receive and hold the strap having the spacer 46a. The ends of the strap are curved to engage with the ends of the stator body so that the ends of the strap wrap around the ends of the stator body and the strap is held within the recess. Each end of the laminate 8 is provided with a stepped portion 81 for receiving the stator body, allowing a part of the stator body to be located below the strap so that the spacer 44a can be securely held. In this configuration, the stator surface 22 can be considered as the stator body 2 (e.g., a bobbin).

[0072] Tight tolerance control is provided at the stepped portion 81 at each end of the stack. The stator body (e.g., bobbin) engages with the stepped portion 81, enabling tight tolerance control in the Y direction. The strap may be a pressed non-iron (e.g., brass) portion positioned on the stator surface, or it may be assembled between the stator body, or it may constitute two complementary bobbins (bobbin halves). The spacer 46a (bearing point) protrudes slightly from the stack surface.

[0073] Figures 21A to 21C show the configuration of a stator and spacer element according to an embodiment of one aspect of the present invention. In this configuration, the spacer 47a is provided on the stator surface 22, more specifically on a plate configured to connect to a recess provided in the stator body. That is, the stator surface 22 is shaped to receive and hold the plate having the spacer 47a. One or more shims 60 may be provided below the spacer plate to achieve a desired protrusion height of the spacer 47a. The stator body may constitute an arm for holding the spacer plate in the recess. In this configuration, the stator surface 22 may be seen as a stator body 2 (e.g., a bobbin).

[0074] This configuration requires minimal tool changes and does not modify the motor's magnetic circuit. The stator body (bobbin) is shaped to receive and secure the spacer plate. The plate may be a stamped non-iron (e.g., brass) sheet assembled between the stator body, which may form two complementary bobbins (bobbin halves), and positioned on the stator surface 22. Shims 60 may be provided between the stator body and the spacer 47a to lift the spacer 47a so that the spacer 47a (bearing point) protrudes slightly from the laminated surface.

[0075] Figures 22A and 22B show the configuration of a stator and spacer element according to an embodiment of one aspect of the present invention. In this configuration, the spacer 48a is provided on the stator surface 22, more specifically on a strip configured to connect to channels provided in the stator body and the laminate 8. That is, the stator surface 22 and the laminate core 8 are shaped to receive and hold the strip having the spacer 48a. The channel in the stator body passes between two laminate cores 8, and each core 8 is provided with a shortened laminate 82. The shortened laminate 82 is aligned with the channel in the stator body so that the channel is continuous through the laminated core 8. The height of the strip body corresponds to the depth of the channel in the laminate core 8 so that when the strip is held in the channel, the upper end of the strip is flat with the end of the laminate core 8 (the part other than the shortened laminate 82). The spacer 48a protrudes from the upper end of the strip and is positioned between the two laminate cores 8.

[0076] The strips in this configuration may be made of one of several different materials to provide a wider range of material options. The shortened laminate 82 may be centrally located within each core 8. The plate may be a pressed non-iron (e.g., brass) sheet placed in a channel on top of the shortened laminate 82 to ensure good tolerance control in the Y direction. The spacers 48a (bearing points) protrude slightly from the laminate surface.

[0077] Figure 23 is a perspective view of a stator according to an embodiment of one aspect of the present invention. In this configuration, the spacer 49a is provided as a projection extending from one end of the laminate of the laminated core 8. In this arrangement, the stator surface 22 may be seen as the end of the laminated core 8.

[0078] One or more laminations of the laminated core 8, for example, the central lamination, are replaced by a lamination that includes a projection providing a spacer 49a. Since the projection is provided on the core lamination, several material options are available. This is a low-cost configuration as no further parts are required. The tolerance in the Y direction is controlled by the tight tolerance of the lamination stamping of the spacer 49a (bearing). The lamination of the spacer 49a may be made of iron or a non-iron material, taking into consideration the balance between bearing properties and magnetic properties. The spacer 49a (bearing point) protrudes slightly from the lamination surface.

[0079] Figure 24 is a perspective view of a stator configuration according to an embodiment of one aspect of the present invention. This configuration is the same as the configuration in Figure 23, except that a laminate with protrusions is provided on each of the two cores 8 to provide two spacers 50a. Thus, one or more laminates of each core of the laminate, such as the central laminate, are replaced with laminates that include protrusions that function as spacers 50a at the ends of each core. The stator surface in this configuration can be considered to have both ends of the laminated cores 8.

[0080] Similar to the configuration in Figure 23, the protrusions are provided on the laminate of each core, so there are several material options. No further parts are needed, making this a low-cost configuration. The tolerance in the Y direction is controlled by the tight tolerance of the laminate stamping of each spacer 50a (bearing). The laminate of each spacer 50a may be made of iron or non-ferrous metal, taking into consideration the balance between bearing properties and magnetic properties. Each spacer 50a (bearing point) protrudes slightly from the laminate surface.

[0081] As can be seen from the above, in embodiments of the present invention, air gap closure can be prevented by clearly setting the minimum air gap with a spacer protruding between the stator and the rotor. Furthermore, the need for shimming procedures during assembly can be avoided. The spacer can prevent the rotor magnets and stator coils from moving too close to each other. The spacer may set the air gap during assembly and control the air gap during its lifespan. For example, if the stator or rotor is not properly secured, the spacer prevents the air gap from closing by providing a protrusion between the stator and the rotor. Therefore, it can be considered a fallback scenario to prevent the air gap from closing completely.

[0082] Although only a few exemplary embodiments are described in detail above, those skilled in the art will readily understand that many modifications are possible in the exemplary embodiments without substantially departing from the novel teachings and advantages of the embodiments of this disclosure. The embodiments described above of the present invention can be advantageously used independently of any other embodiments of the embodiments of this disclosure, or in any practicable combination with one or more other embodiments of the embodiments of this disclosure.

[0083] Accordingly, all such modifications are intended to fall within the scope of the embodiments of this disclosure, as defined in the following claims. In the claims, the means-function clause is intended to cover not only the structures and structural equivalents described herein as performing the listed functions, but also equivalent structures.

[0084] Furthermore, reference numerals placed in parentheses in one or more claims should not be construed as limiting the scope of the claims. Words such as “comprise” and “comprises” do not preclude the existence of elements or steps other than those described in any claim or specification as a whole. A singular reference to an element does not preclude multiple references to such element, nor does it preclude multiple references. One or more embodiments of this embodiment may be implemented by hardware means having multiple different elements. In an apparatus or device of a claim listing multiple means, some of these means may be implemented by the same hardware item. The mere fact that certain means are cited in claims with different dependencies does not imply that combinations of these means cannot be used advantageously.

Claims

1. A motor for a personal care device, A stator having a stator surface, A rotor having a rotor surface positioned opposite the stator surface, A spacer protruding between the stator surface and the rotor surface, defining the minimum air gap between the stator and the rotor, It has, The rotor is configured to rotate at least partially around the axis of rotation relative to the stator, A motor in which the spacer is positioned on one of the rotor surface and the stator surface and has a curved contact surface configured to engage with the other of the rotor surface and the stator surface, the other surface of the spacer being a flat surface.

2. The spacer is aligned with the axis of rotation, The motor according to claim 1.

3. The spacer is at least partially, Wear-resistant materials, Materials with a low coefficient of friction, and Impact-resistant material A motor according to claim 1 or 2, formed from one or more of the above.

4. The motor according to any one of claims 1 to 3, wherein the spacer is formed on the stator or connected to the stator so as to protrude from at least a portion of the stator surface.

5. The motor according to any one of claims 1 to 4, wherein the stator surface is configured to receive a plate having the spacer.

6. The stator has a core formed from a plurality of laminates, The spacer is a projection extending from at least one end of the laminate of the core. The motor according to any one of claims 1 to 5.

7. The motor according to any one of claims 1 to 6, wherein at least a portion of the rotor surface has a low-friction coating.

8. The motor according to any one of claims 1 to 7, wherein at least a portion of the stator surface has a low-friction coating.

9. The motor according to any one of claims 1 to 8, wherein the rotor has a magnet having a magnetic surface that provides the rotor surface.

10. A stator for a motor in a personal care device, wherein the motor has the stator and a rotor, and the stator is Stator surface and, A spacer protruding from the stator surface to engage with the rotor surface of the rotor and defining the minimum air gap between the stator and the rotor, It has, A stator in which the spacer includes a curved contact surface configured to engage with the rotor surface, and the other surface of the spacer is a flat surface.

11. A personal care device having a motor according to any one of claims 1 to 9.

12. A method for manufacturing a motor for a personal care device, A step of mounting a rotor having a rotor surface in the motor, wherein the rotor is configured to rotate at least partially around the rotation axis relative to the stator, The motor comprises the step of arranging a stator having a stator surface adjacent to the rotor, wherein the rotor surface faces the stator surface, and a spacer arranged on either the rotor surface or the stator surface protrudes between the stator surface and the rotor surface, defining the minimum air gap between the stator and the rotor. The steps include moving the stator toward the rotor so that the curved contact surface of the spacer engages with the other of the rotor surface and the stator surface, The steps include fixing the stator, It has, A method wherein the other surface of the spacer is a flat surface.

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