Linear actuator and hair cutting device

Abstract

The invention relates to the technical field of linear motors, and particularly discloses a linear actuator and a hair cutting device.The linear actuator comprises at least one horizontally-arranged electromagnet, the electromagnet is provided with two magnetic poles, and the two magnetic poles are arranged at the two ends of the electromagnet in the axis direction of the electromagnet correspondingly; the two ends of the electromagnets are respectively provided with a magnet group, each magnet group is opposite to the magnetic pole of the electromagnet on the corresponding side, each magnet group comprises at least two magnets, the side, facing the electromagnets, of part of the magnets is an S pole, the side, facing the electromagnets, of the other part of the magnets is an N pole, and after the electromagnets are powered on, the magnets are arranged in the magnet groups. And the magnet group reciprocates along the direction vertical to the central axis of the electromagnet under the magnetic induction action of the electromagnet and the magnet group. By means of the structure, the size of the linear actuator can be reduced.

Description

A linear actuator and hair cutting device Technical Field

[0001] This invention relates to the field of linear motor technology, and in particular to a linear actuator and a hair cutting device having the linear actuator. Background Technology

[0002] A linear actuator is a device used to control linear displacement or force. It generates a magnetic field through electromagnetic induction, using this magnetic field to apply force or motion to the load, thereby achieving linear control of the load. Existing linear actuators include a stator assembly and a mover assembly. The magnetic induction between the stator and mover assemblies enables the mover assembly to drive the load in linear reciprocating motion. Specifically, the electromagnet core in the existing stator assembly typically uses an E-shaped core, with a coil placed on the middle arm of the E-shaped core. When the linear actuator is energized, the E-shaped core becomes energized and magnetized. The magnetized E-shaped core possesses magnetism, generating repulsive or attractive forces with the magnet in the mover assembly, thus causing the load connected to the mover assembly to perform linear reciprocating motion. To ensure smooth linear reciprocating motion of the load, it is necessary to ensure that the core in the stator assembly and the magnet in the mover assembly continuously and alternately attract and repel each other. When two loads need to be driven to move in opposite directions simultaneously, two independently configured... The linear actuator uses two magnets, one driven by an electromagnet, to move linearly in opposite directions. However, due to the large size of the E-shaped core, it is not suitable to use two electromagnets to drive the magnets independently. Using only one E-shaped core for the electromagnet requires consideration of whether the magnetic flux generated by the electromagnet can pass through both magnets simultaneously to ensure continuous linear reciprocating motion. Therefore, the industry typically avoids using two E-shaped cores by appropriately increasing the size of the E-shaped core relative to the magnets, thus ensuring smooth reciprocating motion while appropriately reducing the overall volume. However, this still cannot effectively reduce the size of the linear actuator, requiring a larger installation space for the device or apparatus using it, thereby increasing the size and dimensions of the device or apparatus. Summary of the Invention

[0003] The present invention aims to solve the technical problems existing in the prior art and provide a small linear actuator and a hair cutting device having the linear actuator.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solutions:

[0005] The linear actuator of the present invention includes at least one horizontally arranged electromagnet, which has two magnetic poles. The two magnetic poles are respectively disposed at both ends of the electromagnet along the axial direction of the electromagnet. Magnet groups are respectively disposed at both ends of the electromagnet, and each magnet group is opposite to the magnetic pole of the corresponding side of the electromagnet. The magnet group includes at least two magnets, some of which have the S pole facing the electromagnet as the S pole and the other part of which have the N pole facing the electromagnet as the N pole. After the electromagnet is energized, the magnetic induction between the electromagnet and the magnet group causes the magnet group to reciprocate along the direction perpendicular to the central axis of the electromagnet.

[0006] The linear actuator described in this invention arranges an electromagnet horizontally, with its two magnetic poles positioned at opposite ends along its axial direction. A corresponding magnet group is located at each magnetic pole. When alternating current is applied to the electromagnet, the magnetic induction between the electromagnet and the magnet groups causes the magnet groups to reciprocate along a direction perpendicular to the electromagnet's axial direction. By arranging the electromagnet horizontally and placing the magnet groups to the side of the electromagnet opposite its magnetic poles, the electromagnet is positioned between two magnet groups. The magnetism generated at the two ends of the electromagnet drives one magnet group, fully utilizing the two magnetic poles to ensure smooth and continuous reciprocating motion of the magnet groups. This eliminates the need to increase the number or size of the electromagnets to ensure the movement of the magnet groups, significantly reducing the size of the linear actuator.

[0007] Furthermore, the number of magnets in a single magnet group is one more than the total number of electromagnets.

[0008] Furthermore, there are two electromagnets arranged side by side. When energized, the polarities of the magnetic poles at the same end of all electromagnets are opposite. The magnet group has three magnets, and the polarities of the side of all magnets facing the electromagnet are arranged alternately with S and N poles.

[0009] Alternatively, there are two electromagnets arranged side by side, and when energized, the polarities of the magnetic poles at the same end of all electromagnets are the same; the magnet group has three magnets, and the polarities of the side of all magnets facing the electromagnet are arranged in units of S-S-N, N-S-S, S-N-N, or N-N-S.

[0010] Furthermore, the perpendicular line from the center of the magnet surface is staggered with the central axis of the electromagnet, and the central axis of a single electromagnet is located between the perpendicular lines from the centers of two adjacent magnet surfaces.

[0011] Furthermore, the magnetic pole arrangement of the side of all magnets facing the electromagnet in one group of magnets is the same as that of the side of all magnets facing the electromagnet in another group of magnets.

[0012] Alternatively, the magnetic poles of all magnets in one group of magnets facing the electromagnet are arranged in the opposite way to those of all magnets in another group of magnets facing the electromagnet.

[0013] Furthermore, the electromagnet includes a metal core and an insulating component covering the metal core, with a coil wound around the insulating component. The metal core comprises multiple metal sheets stacked together to form the metal core.

[0014] Furthermore, the linear actuator also includes a mounting frame, which includes an electromagnet mounting section and magnet assembly mounting sections disposed on both sides of the electromagnet mounting section. The electromagnet is horizontally disposed in the electromagnet mounting section, and the magnet assembly is disposed in the magnet assembly mounting section. After the magnet assembly is installed in the magnet assembly mounting section, the magnetic poles of the corresponding ends of the magnet assembly and the electromagnets installed in the electromagnet mounting section are opposite each other.

[0015] Furthermore, the magnet assembly mounting part is elastically connected to the electromagnet mounting part through an elastic connecting part; the elastic connecting part and the electromagnet mounting part are integrally formed or detachably connected by fasteners.

[0016] Alternatively, each magnet assembly mounting section is connected to a drive arm, and an output shaft is provided on the drive arm. The output shaft is located above the mounting frame, and the free ends of the two drive arms are staggered or opposite to each other.

[0017] Furthermore, connecting walls are provided on both sides of the electromagnet mounting part, and a first extension is provided on the connecting wall. A second extension is provided on both sides of the magnet assembly mounting part. The first extension and the second extension on the same side extend in the same direction. The first extension and the second extension on the same side are connected by an elastic connecting part.

[0018] Alternatively, the elastic connection portion includes two first elastic support portions; the elastic connection portion further includes a second elastic support portion, the second elastic support portion being located between the two first elastic support portions, and the thickness of the second elastic support portion being greater than the thickness of the first elastic support portions on both sides thereof.

[0019] The hair cutting device of the present invention includes a housing and a moving blade assembly. The linear actuator described above is disposed inside the housing. The moving blade assembly is connected to the magnet assembly mounting part. The moving blade assembly moves back and forth with the magnet assembly under the power provided by the magnet assembly of the linear actuator.

[0020] The hair cutting device of the present invention, having the aforementioned linear actuator, possesses all the beneficial technical effects brought about by the aforementioned linear actuator, which will not be elaborated upon here. Furthermore, since the hair cutting device employs the aforementioned small-sized linear actuator, the size of the hair cutting device can also be reduced, making it easier to carry and store. Attached Figure Description

[0021] The above and other objects, features, and advantages of the invention will become clearer through a more detailed description of the preferred embodiments illustrated in the accompanying drawings. The same reference numerals denote the same parts throughout the drawings, and the drawings are not intentionally drawn to scale with actual dimensions; the focus is on illustrating the gist of the invention.

[0022] Figure 1 is a perspective view of one embodiment of the linear actuator of the present invention.

[0023] Figure 2 is a schematic diagram of the decomposition of Figure 1.

[0024] Figure 3 is a schematic diagram of the structure of the two electromagnets.

[0025] Figure 4 is a schematic diagram of the magnet assembly structure.

[0026] Figure 5 is a schematic diagram of the reciprocating linear motion of the magnet assembly relative to the electromagnet (Example 1).

[0027] Figure 6 is a schematic diagram of the reciprocating linear motion of the magnet assembly relative to the electromagnet (Example 2).

[0028] Figure 7 is a top view of the linear actuator (with the electromagnet retainer and drive arm removed).

[0029] Figure 8 is a schematic diagram of the movement direction of the two sets of magnets (Example 1).

[0030] Figure 9 is a schematic diagram of the movement direction of the two sets of magnets (Example 2).

[0031] Figure 10 is a schematic diagram of the installation frame structure.

[0032] Figure 11 is a schematic diagram of one embodiment of the drive arm.

[0033] Figure 12 is an exploded view of Embodiment 2 of the linear actuator of the present invention.

[0034] Figures 13 and 14 are schematic diagrams of a third embodiment of the linear actuator of the present invention. Detailed Implementation

[0035] To facilitate understanding of the present invention, a more comprehensive description will be given below with reference to the accompanying drawings.

[0036] It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to and integrated with the other component, or there may be an intervening component present. The terms "mounted," "one end," "the other end," and similar expressions used in this document are for illustrative purposes only.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0038] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0039] In the description of this specification, the references to terms such as "preferred embodiment," "another embodiment," "other embodiment," or "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0040] This invention provides a specific embodiment of a linear actuator, as shown in Figures 1-3 and 12-14. It includes at least one horizontally arranged electromagnet 100. The number of electromagnets 100 can be one or more; this embodiment uses two electromagnets 100, which can generate two pairs of magnetic field combinations, increasing the stability of the reciprocating motion of the magnet assembly 300 and increasing the magnetic force, while also saving costs. Each electromagnet 100 includes a metal core 110 and an insulating component 130 covering the metal core 110. The insulating component 130 can be an insulating winding box or insulating tape, etc. A coil 120 is wound around the insulating component 130. The metal core 110 includes multiple metal sheets 111, which are stacked to form the metal core 110. The metal core 110 includes at least five metal sheets 111, and the thickness of each metal sheet 111 is less than or equal to 0.5 mm. The metal sheet 111 can be I-shaped, making the resulting metal core 110 compact and reducing its size. When the required thickness of the metal core 110 is needed, multiple metal sheets 111 need to be assembled together to achieve the overall thickness of the metal core 110. For example, when the required overall thickness of the metal core 110 is 3mm, if 0.3mm metal sheets 111 are used, ten metal sheets 111 are needed; if 0.5mm metal sheets 111 are used, six metal sheets 111 are needed. In addition, the thickness of the metal sheet 111 is set to within 0.5mm (inclusive) so that eddy currents are not generated inside the metal sheet 111 when magnetization is applied, saving energy consumption and significantly reducing heat generation, without affecting the performance and energy efficiency of the linear actuator. When the insulating component 130 is an insulating winding box, it is made of polymer material and its thickness does not exceed 1mm (inclusive). Excessive thickness of the winding box will affect the magnetic conductivity and occupy space.

[0041] In this embodiment, referring to Figures 1, 2, and 4, the electromagnet 100 has two magnetic poles 112, which are respectively disposed at both ends of the electromagnet 100 along the axial direction of the electromagnet 100. The axial direction is the central axis B of the metal core 110 formed by stacking I-shaped metal sheets 111 in the length direction. Magnet groups 300 are respectively disposed at both ends of the electromagnet 100, and each magnet group 300 is opposite to the magnetic pole 112 of the corresponding side of the electromagnet 100. This structure can drive at least two components that need to perform linear motion to reciprocate in the same or opposite directions. The magnet group 300 includes at least two magnets 320, that is, there can be two or more magnets 320. The magnet assembly 300 also includes a magnetically conductive metal 310, and magnets 320 are arranged on the surface of the magnetically conductive metal 310 along its length. Some magnets 320 have an S pole on the side facing the electromagnet 100, and other magnets 320 have an N pole on the side facing the electromagnet 100. In the same magnet assembly 300, since some magnets 320 have an S pole on the side facing the electromagnet 100 and other magnets 320 have an N pole on the side facing the electromagnet 100, after the electromagnet 100 is energized, the magnetic induction between the electromagnet 100 and the magnet assembly 300 causes the magnet assembly 300 to reciprocate along the direction B perpendicular to the central axis of the electromagnet 100.

[0042] In this embodiment, the linear actuator arranges the electromagnet 100 horizontally, with its two magnetic poles 112 positioned at both ends of the electromagnet 100 along the central axis B of the electromagnet 100. A corresponding magnet group 300 is provided at each magnetic pole 112 of the electromagnet 100. When alternating current is applied to the electromagnet 100, the magnetic induction between the electromagnet 100 and the magnet group 300 causes the magnet group 300 to reciprocate along the direction perpendicular to the central axis B of the electromagnet 100. By arranging the electromagnet 100 horizontally and placing the magnet assembly 300 to the side of the electromagnet 100 and opposite to the magnetic poles 112 of the electromagnet 100, the electromagnet 100 is positioned between the two magnet assemblies 300. The magnetism generated at the two ends of the electromagnet 100 drives one magnet assembly 300 respectively, making full use of the two magnetic poles 112 of the electromagnet 100 to ensure smooth and continuous reciprocating motion of the magnet assembly 300. This eliminates the need to increase the number or size of the electromagnet 100 to ensure the movement of the magnet assembly 300, thus significantly reducing the volume of the linear actuator.

[0043] In a preferred embodiment, referring to Figure 7, the number of magnets 320 in a single magnet group 300 is one more than the total number of electromagnets 100. The perpendicular line A to the center of the surface of the magnet 320 is staggered with the central axis B of the electromagnet 100. The central axis B of a single electromagnet 100 is located between the perpendicular lines A of the centers of the surfaces of two adjacent magnets 320. Preferably, the central axis B of a single electromagnet 100 coincides with the junction of two adjacent magnets 320. This ensures that the magnetic flux generated by a single electromagnet 100 (at least more than half of the magnetic flux) passes through at least two magnets 320 located on the same side at the same time, further ensuring that the magnet group 300 performs smooth reciprocating linear motion.

[0044] In a preferred embodiment, there are two electromagnets 100 arranged side by side. When energized, the polarities of the magnetic poles 112 at the same end of all electromagnets 100 are opposite. The magnet group 300 has three magnets 320, and the polarities of the sides of all magnets 320 facing the electromagnets 100 are arranged alternately as S and N poles. For example, when there are two electromagnets 100, after alternating current is applied, at the same end of the two electromagnets 100, the magnetic pole 112 of one electromagnet 100 is N pole, and the magnetic pole 112 of the other electromagnet 100 is S pole. The opposite polarities of the magnetic poles 112 at the same end of the two electromagnets 100 can be achieved by the opposite winding direction of the coil 120, so that after the two electromagnets 100 are connected in series, the currents flowing through the coil 120 are opposite, thereby making the two electromagnets 100... The magnetic poles 112 at the same end of the magnet 100 have opposite polarities; alternatively, two electromagnets 100 can be connected in parallel with their positive and negative terminals connected in opposite directions, causing the current to flow in opposite directions in the coil 120, thus making the magnetic poles 112 at the same end of the two electromagnets 100 have opposite polarities. However, this structure requires the two electromagnets 100 to be controlled separately, increasing the structural complexity of the control circuit and raising the manufacturing cost of the linear actuator. In this case, the magnet group 300 has three magnets 320, and the polarity of the side of the three magnets 320 facing the electromagnet 100 can be S-N-S or N-S-N, as shown in Figure 5, which illustrates the reciprocating linear motion of the magnet group 300 relative to the electromagnet 100 in this embodiment. The magnet group 300 moves upward in the direction of the arrow. Alternatively, in another embodiment, there are two electromagnets 100, arranged side by side. When energized, the magnetic poles 112 at the same end of all electromagnets 100 have the same polarity. The magnet group 300 has three magnets 320, and the polarities of the sides of all magnets 320 facing the electromagnets 100 are arranged in a unit pattern of S-S-N, N-S-S, S-N-N, or N-N-S. For example, when the electromagnets 100... When there are two magnets 100, after AC energizing, the polarity of the magnetic poles 112 at the same end of both magnets 100 is N (north). At this time, the magnet assembly 300 has three magnets 320, and the polarity of the side of the three magnets 320 facing the electromagnet 100 can be S-S-N, N-S-S, S-N-N, or N-N-S, as shown in Figure 6. This figure illustrates the reciprocating linear motion of the magnet assembly 300 relative to the electromagnet 100 in this embodiment, with the magnet assembly 300 moving downwards in the direction of the arrow. This structure ensures that the magnet assembly 300 can smoothly perform reciprocating linear motion.

[0045] In a preferred embodiment, the magnetic pole arrangement of all magnets 320 in one group of magnets 300 facing the electromagnet 100 is the same as that of all magnets 320 in another group of magnets 300 facing the electromagnet 100. For example, each group of magnets 300 has three magnets 320, and the magnetic pole arrangement of all magnets 320 in one group of magnets 300 facing the electromagnet 100 is S-N-S, and the magnetic pole arrangement of all magnets 320 in the other group of magnets 300 facing the electromagnet 100 is also S-N-S. As shown in Figure 8, which is a schematic diagram of the movement directions of the two groups of magnets 300, the two groups of magnets 300 move in opposite directions. By making the movement directions of the two groups of magnets 300 opposite, To reduce amplitude, alleviate vibration, and lower noise; or, in another embodiment, the magnetic pole arrangement of all magnets 320 in one group of magnets 300 facing the electromagnet 100 is opposite to that of all magnets 320 in another group of magnets 300 facing the electromagnet 100. For example, each group of magnets 300 has three magnets 320, and the magnetic pole arrangement of all magnets 320 in one group of magnets 300 facing the electromagnet 100 is S-pole-N-S-pole, while the magnetic pole arrangement of all magnets 320 in another group of magnets 300 facing the electromagnet 100 is N-pole-S-pole-N-pole, as shown in Figure 9, which is a schematic diagram of the movement direction of the two groups of magnets 300. In this case, the movement direction of the two groups of magnets 300 is the same.

[0046] In a preferred embodiment, the linear actuator further includes a mounting frame 200. The mounting frame 200 has multiple implementations, and three specific implementations are given in this invention. In the first implementation, referring to Figures 1, 2, 7 and 10, the mounting frame 200 includes an electromagnet mounting part and magnet assembly mounting parts disposed on both sides of the electromagnet mounting part. The electromagnet 100 is horizontally disposed in the electromagnet mounting part, and the magnet assembly 300 is disposed in the magnet assembly mounting part. After the magnet assembly 300 is installed in the magnet assembly mounting part, the magnetic poles 112 at the corresponding ends of the electromagnet 100 installed in the electromagnet mounting part are opposite to each other. Specifically, the magnet assembly mounting part is elastically connected to the electromagnet mounting part through an elastic connecting part, and the electromagnet mounting part is connected to the elastic connecting part through a connecting wall 201. The three are integrally formed, simplifying the production process and reducing assembly errors during assembly. Connecting walls 201 are provided on both sides of the electromagnet mounting portion, and first extension portions 213 are provided on the connecting walls 201. Second extension portions 214 are provided on both sides of the magnet assembly mounting portion. The first extension portions 213 and second extension portions 214 on the same side extend in the same direction and are connected by elastic connecting portions. Specifically, the magnet assembly mounting portion includes a side wall 230 and a pair of stops 202 extending from one side of the side wall 230 toward the electromagnet mounting portion. The two stops 202 are spaced apart to provide mounting space for the magnet assembly 300. The second extension portions 214 are provided at both ends of the side wall 230 and are formed by extending outward from both ends of the side wall 230. Component 202 prevents the magnet assembly 300 from detaching from the magnet assembly mounting part during reciprocating motion. The electromagnet mounting part includes a supporting bottom surface and symmetrically spaced supporting walls 210 on the supporting bottom surface. Two grooves 211 are spaced apart on the end faces of the two supporting walls 210, and the two grooves 211 on the two supporting walls 210 correspond one-to-one. When the two electromagnets 100 are installed in the electromagnet mounting part, the two ends of their metal cores 110 are supported in the corresponding grooves 211. The electromagnets 100 are pressed and secured in the electromagnet mounting part by the electromagnet fixing piece 212. Since the electromagnet mounting part is fixed, while the magnet assembly mounting part will reciprocate with the magnet assembly 300, the elastic connecting part plays a role in buffering and elastic reset. The electromagnet mounting part, the magnet assembly mounting part, the elastic connecting part, the connecting part 201, and the extension part can be assembled to form the mounting frame 200, or the mounting frame 200 can be directly formed by an integral molding process. In this embodiment, the integral molding method is adopted. The mounting frame 200 is made of plastic, which facilitates the deformation and recovery of the elastic connection.In this embodiment, referring to Figure 10, the elastic connection portion includes at least one first elastic support portion 220. In this embodiment, two first elastic support portions 220 are provided, and a second elastic support portion 240 is also included. The second elastic support portion 240 is located between the two first elastic support portions 220, and the thickness of the second elastic support portion 240 is greater than the thickness of the first elastic support portion 220. The second elastic support portion 240 stores more elastic potential energy to help the magnet assembly 300 return to its original position. At the same time, by placing the thicker second elastic support portion 240 between the two thinner first elastic support portions 220, the deformation of the first elastic support portions 220 on both sides can be more uniform during movement, avoiding any first elastic support portion 220 from being damaged or broken first because its deformation is greater than that of the other first elastic support portions 220. In addition, one end of the first elastic support portion 220 is connected to the first extension portion 213, and the other end is connected to the second extension portion 214. One end of the second elastic support portion 240 is connected to the first extension portion 213, and the other end is connected to the second extension portion 214. The portion of the second extension portion 214 located between the first elastic support portion 220 and the second elastic support portion 240, and the portion located between the first elastic support portion 220 and the adjacent stop 202 (which can be understood as located between the first elastic support portion 220 and the magnet assembly mounting portion) is set to an arc shape 222. The portion of the first extension portion 213 located between the first elastic support portion 220 and the second elastic support portion 240, and the portion located between the first elastic support portion 220 and the adjacent connecting wall 201 is also set to an arc shape 222. The radius of the arc shape 222 is 0.5 mm or more (including 0.5 mm). By setting the arc shape 222 and limiting its radius, the stress at the edge of the connection can be distributed, and the stress can be prevented from exceeding the material strength and causing cracks. In this embodiment, referring to Figures 1, 2, and 11, a drive arm 400 is connected to the magnet assembly mounting portion, and an output shaft 421 is provided on the drive arm 400, with the output shaft 421 located above the mounting frame 200. The drive arm 400 includes a fixing portion 410 and an output shaft connecting portion 420. The fixing portion 410 is connected to the side wall 230 of the magnet assembly mounting portion, while the output shaft connecting portion 420 is bent relative to the fixing portion 410 and located above the mounting frame 200. The output shaft 421 is mounted on the output shaft connecting portion 420. The number of output shafts 421 is determined by the number of components that need to perform reciprocating linear motion. In this embodiment, each drive arm 400 is provided with two output shafts 421. The two output shafts 421 on the same side are arranged at intervals along the direction perpendicular to the reciprocating motion of the magnet group 300. That is, one magnet group 300 drives two output shafts 421 to perform reciprocating linear motion, and two magnet groups 300 drive four output shafts 421 to perform reciprocating linear motion. For example, when the component that needs to perform reciprocating linear motion is the moving blade in the hair cutting device, four moving blades can be set, which results in high cutting efficiency and cleaner shaving.In this embodiment, referring to Figures 1 and 2, a positioning hole is provided on the drive arm 400, and a positioning protrusion is provided on the magnet assembly mounting part. When the drive arm 400 is connected to the magnet assembly 300 mounting part, the positioning protrusion is inserted into the positioning hole to position the drive arm 400, facilitating the positioning and installation of the drive arm 400. In this embodiment, the free ends of the two drive arms 400 are arranged opposite each other.

[0047] The present invention also provides a second embodiment of the mounting frame 200. Referring to Figure 12, the mounting frame 200 in this embodiment has a structure that is largely the same as that in the first embodiment, except that in this embodiment, the electromagnet mounting part is formed independently and then assembled with the connecting wall 201 and the elastic connecting part. Specifically, the electromagnet mounting part includes two symmetrically arranged and spaced support walls 210. The two sides of the two support arms 210 are connected by side edges 203 respectively. The top surface 2031 of each side edge 203 is concave or convex, while the bottom surface 2011 of the connecting wall 201 is aligned with the corresponding side edge 203. The top surface 2031 is adapted to the shape of the connecting wall 201. For example, when the top surface 2031 of the side 203 is concave, the bottom surface 2011 of the connecting wall 201 is convex, and vice versa. When assembling the electromagnet mounting part with the connecting wall 201, the support arm 210 of the electromagnet mounting part is inserted between the two connecting walls 201. The top surface 2031 of the side 203 of the electromagnet mounting part abuts against the bottom surface 2011 of the corresponding side connecting wall 201, and the side 203 is fastened to the corresponding side connecting wall 201 by fasteners, thereby connecting the electromagnet mounting part with the connecting wall 201 and indirectly connecting it with the elastic connecting part. In addition, this embodiment differs from the first embodiment described above in that the drive arm 400 and the magnet assembly mounting part are integrally formed, thereby simplifying the manufacturing process and avoiding errors caused by assembly. Specifically, the drive arm 400 includes an output shaft connecting part 420, which is directly integrally formed with the magnet assembly mounting part.

[0048] The present invention also provides a third embodiment of the mounting frame 200. Referring to Figure 13, the mounting frame 200 in this embodiment has a structure that is largely the same as that in the second embodiment described above. The difference is that the free ends of the two drive arms 400 in this embodiment are staggered. By setting the two drive arms 400 in a staggered state, better dynamic balance can be achieved, and vibration can be further reduced. Specifically, there are two specific implementations for the staggered arrangement of the free ends of the two drive arms 400. One is shown in Figure 14, where the free ends of the two drive arms 400 are staggered. The other is shown in Figure 13, where the output shaft connection portion 420 of the drive arm 400 includes a connected head 4. 001 and neck 4002, drive arm 400 is integrally connected to magnet assembly mounting part through neck 4002. The size of head 4001 is larger than that of neck 4002, and the connection between head 4001 and neck 4002 is a concave arc 403. The concave arc 403 and neck form a receiving groove. Part of the head of one drive arm 400 extends into the receiving groove of the other drive arm 400. At the same time, the output shaft 421 on the two drive arms 400 is located on head 4001. The output shaft 421 on the head 4001 of the two drive arms 400 are arranged side by side, so that the free ends of the two drive arms 400 are staggered.

[0049] In the second and third embodiments described above, the fixing piece 212 may not be necessary.

[0050] This invention also provides a specific embodiment of a hair cutting device, including a housing and moving blade assemblies. The structure of the moving blade assemblies is existing technology. In this embodiment, four moving blade assemblies are used. The aforementioned linear actuator is disposed within the housing. The moving blade assemblies are connected to the magnet assembly mounting portion. Under the power provided by the magnet assembly 300 of the linear actuator, the moving blade assemblies reciprocate with the magnet assembly 300. Specifically, the moving blade assemblies are connected to the output shaft 421 and connected to the magnet assembly mounting portion via a drive arm 400, allowing them to perform reciprocating linear motion with the magnet assembly 300 for hair cutting. Because this hair cutting device uses the aforementioned small-sized linear actuator, the size of the hair cutting device can also be reduced, making it easier to carry and store, and improving the aesthetics of the hair cutting device. Furthermore, the hair cutting device, due to the aforementioned linear actuator, also possesses all the beneficial technical effects it brings, which will not be elaborated further here.

[0051] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A linear actuator, characterized in that: The device includes at least one horizontally arranged electromagnet, which has two magnetic poles located at both ends of the electromagnet along its axial direction. Magnet groups are respectively arranged at both ends of the electromagnet, with each magnet group opposite to the magnetic pole of the corresponding side of the electromagnet. Each magnet group includes at least two magnets, with one magnet having an S pole facing the electromagnet and the other having an N pole facing the electromagnet. When the electromagnet is energized, the magnetic induction between the electromagnet and the magnet groups causes the magnet groups to reciprocate along the direction perpendicular to the central axis of the electromagnet.

2. The linear actuator according to claim 1, characterized in that: The number of magnets in a single magnet group is one more than the total number of electromagnets.

3. The linear actuator according to claim 1 or 2, characterized in that: There are two electromagnets, which are arranged side by side. When energized, the polarities of the magnetic poles at the same end of all the electromagnets are opposite. The magnet group has three magnets, and the polarities of the sides of all magnets facing the electromagnet are arranged alternately with S and N poles; or, there are two electromagnets, which are arranged side by side, and when energized, the polarities of the magnetic poles at the same end of all electromagnets are the same; the magnet group has three magnets, and the polarities of the sides of all magnets facing the electromagnet are arranged in units of S-S-N, N-S-S, S-N-N, or N-N-S.

4. The linear actuator according to claim 2, characterized in that: The perpendicular line from the center of the magnet surface is offset from the central axis of the electromagnet, and the central axis of a single electromagnet is located between the perpendicular lines from the centers of the surfaces of two adjacent magnets.

5. The linear actuator according to any one of claims 1-4, characterized in that: The magnetic pole arrangement of the magnets facing the electromagnet in one group of magnets is the same as that of the magnets facing the electromagnet in another group of magnets; or, the magnetic pole arrangement of the magnets facing the electromagnet in one group of magnets is the opposite of that of the magnets facing the electromagnet in another group of magnets.

6. The linear actuator according to claim 1, characterized in that: The electromagnet includes a metal core and an insulating component covering the metal core. A coil is wound around the insulating component. The metal core includes multiple metal sheets stacked together to form the metal core.

7. The linear actuator according to claim 1, characterized in that: The linear actuator also includes a mounting frame, which includes an electromagnet mounting section and magnet assembly mounting sections disposed on both sides of the electromagnet mounting section. The electromagnet is horizontally disposed in the electromagnet mounting section, and the magnet assembly is disposed in the magnet assembly mounting section. After the magnet assembly is installed in the magnet assembly mounting section, the magnetic poles of the corresponding ends of the magnet assembly and the electromagnets installed in the electromagnet mounting section are opposite each other.

8. The linear actuator according to claim 7, characterized in that: The magnet assembly mounting part is elastically connected to the electromagnet mounting part through an elastic connecting part; the elastic connecting part and the electromagnet mounting part are integrally formed or detachably connected by fasteners; or, each magnet assembly mounting part is connected to a drive arm, and an output shaft is provided on the drive arm. The output shaft is located above the mounting frame, and the free ends of the two drive arms are staggered or opposite to each other.

9. The linear actuator according to claim 7 or 8, characterized in that: Connecting walls are provided on both sides of the electromagnet mounting part, and a first extension is provided on the connecting wall. A second extension is provided on both sides of the magnet assembly mounting part. The first and second extensions on the same side extend in the same direction and are connected to each other by an elastic connecting part. Alternatively, the elastic connecting part includes two first elastic support parts. The elastic connecting part also includes a second elastic support part, which is located between the two first elastic support parts. The thickness of the second elastic support part is greater than the thickness of the first elastic support parts on both sides.

10. A hair cutting device, comprising a housing and a moving blade assembly, characterized in that: A linear actuator as described in any one of claims 1-9 is provided inside the housing, the moving blade assembly is connected to the magnet assembly mounting part, and the moving blade assembly reciprocates with the magnet assembly under the power provided by the magnet assembly of the linear actuator.

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