Linear driver and hair cutting device

Abstract

The utility model relates to the technical field of linear motors, and particularly discloses a linear driver and a hair cutting device, the linear driver comprises a mounting frame, the mounting frame comprises an electromagnet mounting part and two magnet group mounting parts, the two magnet group mounting parts are oppositely arranged at an interval, and the electromagnet mounting part is connected with the electromagnet mounting part. The electromagnet mounting part is located between the two magnet group mounting parts, the two ends of each magnet group mounting part are elastically connected with the corresponding ends of the electromagnet mounting part through elastic connecting parts, each magnet group mounting part is connected with a driving arm, and at least one output shaft is arranged on each driving arm; the number of the output shafts on one magnet group mounting part is greater than that of the output shafts on the other magnet group mounting part, and each output shaft is connected with a load; each magnet group mounting part, the driving arm on the magnet group mounting part, the output shaft, the load and the elastic connecting parts at the two ends of the magnet group mounting part form a whole, and the inherent frequencies of the two whole bodies are the same, so that the function of a product applied to the linear actuating device is achieved.

Description

Technical Field

[0001] This utility model relates to the field of linear motor technology, and in particular to a linear driver and a hair-cutting device containing the linear driver. Background Technology

[0002] A linear actuator is a device used to control linear displacement or force. It generates a magnetic field through electromagnetic induction, and uses this magnetic field to apply force or movement to the load, thereby achieving linear control of the load. Some existing linear actuators have two drive arms with the same number of output shafts on each. In this case, a single drive arm, its output shaft, and the load connected to the output shaft (which could be the moving blade of a hair cutter) form a unit. Both such units have the same natural frequency. When the linear actuator receives an electrical signal and starts operating, the two units with the same natural frequency will vibrate synchronously. However, when the number of output shafts on the two drive arms is different, the natural frequencies of the two units will be different. In this case, when the linear actuator receives an electrical signal and starts operating, the two units with different natural frequencies will not be able to vibrate synchronously, thus failing to achieve the function of the product to which the linear actuator is applied. For example, when the load is a hair cutter, the moving blades on the two drive arms cannot vibrate synchronously. Utility Model Content

[0003] This invention aims to solve the technical problems existing in the prior art and provide a linear actuator capable of synchronizing the vibration of two drive arms. Furthermore, this invention also provides a hair-cutting device incorporating the aforementioned linear actuator.

[0004] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0005] The linear actuator of this utility model includes a mounting frame, which includes an electromagnet mounting part and two magnet assembly mounting parts. The two magnet assembly mounting parts are arranged opposite to each other and spaced apart. The electromagnet mounting part is located between the two magnet assembly mounting parts. Both ends of each magnet assembly mounting part are elastically connected to the corresponding ends of the electromagnet mounting part through elastic connecting parts. A drive arm is connected to each magnet assembly mounting part, and at least one output shaft is provided on the drive arm. The number of output shafts on one magnet assembly mounting part is greater than the number of output shafts on the other magnet assembly mounting part, and each output shaft is connected to a load. Each magnet assembly mounting part, its drive arm, output shaft, load, and elastic connecting parts at both ends form a whole. The natural frequencies of the two wholes are the same, or the natural frequencies of the two wholes differ by less than 5%.

[0006] The present invention describes a linear actuator in which each magnet assembly mounting part, its drive arm, output shaft, load, and elastic connection parts at both ends form a whole. When the natural frequencies of the two wholes are the same, the linear actuator can make all the loads vibrate at the same frequency when it is working, so as to realize the function of the product to which the linear actuator is applied.

[0007] Furthermore, the elastic connection portion includes a first elastic connection portion and a second elastic connection portion. The first elastic connection portion and the second elastic connection portion are respectively connected to the magnet assembly mounting portion on the corresponding side. The number of output shafts on the drive arm of the magnet assembly mounting portion connected to the first elastic connection portion is greater than the number of output shafts on the drive arm of the magnet assembly mounting portion connected to the second elastic connection portion. The first elastic connection portion includes a first elastic support portion, and the second elastic connection portion includes a second elastic support portion. The wall thickness of the first elastic support portion is greater than the wall thickness of the second elastic support portion, and the wall thickness of the first elastic support portion is 10%-30% greater than the wall thickness of the second elastic support portion. The length of the first elastic support portion is the same as the length of the second elastic support portion, so that the natural frequencies of the two components are the same, or the natural frequencies of the two components differ by less than five percent.

[0008] Furthermore, the elastic connection portion includes a first elastic connection portion and a second elastic connection portion. The first elastic connection portion and the second elastic connection portion are respectively connected to the magnet assembly mounting portion on the corresponding side. The number of output shafts on the drive arm of the magnet assembly mounting portion connected to the first elastic connection portion is greater than the number of output shafts on the drive arm of the magnet assembly mounting portion connected to the second elastic connection portion. The first elastic connection portion includes a first elastic support portion, and the second elastic connection portion includes a second elastic support portion. The length of the first elastic support portion is shorter than the length of the second elastic support portion, and the length of the first elastic support portion is 10%-30% shorter than the length of the second elastic support portion. The wall thickness of the first elastic support portion is the same as the wall thickness of the second elastic support portion, so that the natural frequencies of the two components are the same, or the natural frequencies of the two components differ by less than five percent.

[0009] Furthermore, F1 is the result of dividing the square root of the ratio of the elastic coefficient of the first elastic connection at both ends of one magnet assembly mounting part to the mass of the entire assembly formed by the magnet assembly mounting part, the drive arm, the output shaft, the load, and the first elastic connection at both ends by 2π. F2 is the result of dividing the square root of the ratio of the elastic coefficient of the second elastic connection at both ends of the other magnet assembly mounting part to the mass of the entire assembly formed by the magnet assembly mounting part, the drive arm, the output shaft, the load, and the second elastic connection at both ends by 2π. F1 = F2, or |F1-F2| ≤ 0.05 × min(F1, F2), where min(F1, F2) represents the smaller value of F1 and F2.

[0010] Furthermore, the first elastic connection portion also includes a third elastic support portion, there are two third elastic support portions, the first elastic support portion is located between the two third elastic support portions, and the thickness of the first elastic support portion is greater than the thickness of the third elastic support portions on both sides of it.

[0011] The second elastic connection portion further includes a fourth elastic support portion, there are two fourth elastic support portions, the second elastic support portion is located between the two fourth elastic support portions, and the thickness of the second elastic support portion is greater than the thickness of the fourth elastic support portions on both sides thereof.

[0012] Furthermore, the elastic connection portion also includes a first extension portion respectively disposed on two opposite sides of the electromagnet mounting portion. The first elastic connection portion includes a second extension portion, and the second elastic connection portion includes a third extension portion. The second extension portion and the third extension portion are both formed by extending out from the magnet assembly mounting portion on the corresponding side. The first extension portion is located between the first elastic connection portion and the second elastic connection portion on the same side. The first extension portion and the second extension portion on the same side are connected by a first elastic support portion and a third elastic support portion. The first extension portion and the third extension portion on the same side are connected by a second elastic support portion and a fourth elastic support portion.

[0013] Furthermore, connecting walls are provided on two opposite sides of the electromagnet mounting part, and each connecting wall is connected to the first extension on the same side. The portion of the first extension located between the first elastic support and the third elastic support, the portion located between the third elastic support and the connecting wall, the portion located between the second elastic support and the fourth elastic support, and the portion located between the fourth elastic support and the connecting wall are all set in an arc shape.

[0014] The portion of the second extension located between the first elastic support portion and the third elastic support portion, and the portion located between the third elastic support portion and the magnet assembly mounting portion, are configured as arc-shaped.

[0015] The portion of the third extension located between the second elastic support portion and the fourth elastic support portion, and the portion located between the fourth elastic support portion and the magnet assembly mounting portion, are configured as arc-shaped.

[0016] Furthermore, each magnet assembly is provided in the magnet assembly mounting section, and an electromagnet is horizontally arranged in the electromagnet mounting section. After the magnet assembly is installed in the magnet assembly mounting section, one end of the magnetic pole of each magnet assembly is opposite to that of the electromagnet installed in the electromagnet mounting section.

[0017] One drive arm has three output shafts, and the other drive arm has two output shafts; or, one drive arm has two output shafts, and the other drive arm has one output shaft.

[0018] Furthermore, a positioning hole is provided on the drive arm, and a positioning protrusion is provided on the magnet assembly mounting part. When the drive arm is connected to the magnet assembly mounting part, the positioning protrusion is inserted into the positioning hole to position the drive arm, or the drive arm and the magnet assembly mounting part are integrally formed.

[0019] The free ends of the two drive arms are either staggered or opposite to each other.

[0020] The present invention discloses a hair cutting device, comprising a housing, wherein the aforementioned linear driver is disposed within the housing, and the load is a moving blade assembly. The number of moving blade assemblies is consistent with the number of all output shafts, and one moving blade assembly is connected to each output shaft. The moving blade assembly reciprocates with the magnet assembly under the power provided by the magnet assembly of the linear driver.

[0021] The hair-cutting device described in this utility model, due to the aforementioned linear actuator, enables all moving blade components on the two drive arms to vibrate at the same frequency, thereby achieving effective hair cutting. Furthermore, the hair-cutting device, due to the aforementioned linear actuation device, also possesses all the beneficial technical effects it brings, which will not be elaborated upon here. Attached Figure Description

[0022] The above and other objects, features, and advantages of this invention will become clearer through a more detailed description of the preferred embodiments shown in the accompanying drawings. The same reference numerals indicate 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 this invention.

[0023] Figure 1 This is a perspective view of one embodiment of the linear actuator of this utility model.

[0024] Figure 2 for Figure 1 Main view.

[0025] Figure 3 This is a perspective view of one embodiment of the linear actuator of this utility model.

[0026] Figure 4 for Figure 2 Main view.

[0027] Figure 5 This is a perspective view of one embodiment of the linear actuator of this utility model.

[0028] Figure 6 for Figure 5 A schematic diagram of its breakdown.

[0029] Figure 7 This is a schematic diagram of two electromagnets.

[0030] Figure 8 This is a schematic diagram of the magnet assembly structure.

[0031] Figure 9 This is a schematic diagram of the reciprocating linear motion of the magnet assembly relative to the electromagnet (Example 1).

[0032] Figure 10 This is a schematic diagram of the reciprocating linear motion of the magnet assembly relative to the electromagnet (Example 2).

[0033] Figure 11 Top view of the linear actuator (with the electromagnet retaining plate and drive arm removed).

[0034] Figure 12 This is a schematic diagram showing the movement directions of the two sets of magnets (Example 1).

[0035] Figure 13 This is a schematic diagram showing the movement directions of the two sets of magnets (Example 2).

[0036] Figure 14 This is a schematic diagram of the installation frame structure.

[0037] Figure 15 This is a schematic diagram of the drive arm structure.

[0038] Figure 16 This is a schematic diagram of one embodiment of the linear actuator of this utility model.

[0039] Figure 17 This is a schematic diagram of one embodiment of the linear actuator of this utility model. Detailed Implementation

[0040] To facilitate understanding of this utility model, a more comprehensive description will be given below with reference to the accompanying drawings.

[0041] 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.

[0042] 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.

[0043] This embodiment provides a specific implementation of a linear driver; see [link to relevant documentation]. Figure 1-17 The system includes a mounting frame 200, which comprises an electromagnet mounting section and two magnet assembly mounting sections. The two magnet assembly mounting sections are arranged opposite each other and spaced apart. The electromagnet mounting section is located between the two magnet assembly mounting sections. Both ends of each magnet assembly mounting section (the "both ends" here refers to the two ends along the length of the magnet assembly mounting section) are elastically connected to the corresponding ends of the electromagnet mounting section through elastic connecting sections. A drive arm 400 is connected to each magnet assembly mounting section. At least one output shaft 421 is provided on the drive arm 400. The number of output shafts 421 on one magnet assembly mounting section is greater than the number of output shafts 421 on the other magnet assembly mounting section, and a load is connected to each output shaft 421. Each magnet assembly mounting section, its drive arm 400, output shaft 421, load, and elastic connecting sections at both ends form a whole, and the natural frequencies of the two wholes are the same. Since the number of output shafts 421 and the number of loads on each drive arm 400 are different, it will affect the overall quality of the whole formed by each magnet assembly mounting part and its drive arm 400, output shaft 421, load, and elastic connection parts at both ends. Therefore, it is necessary to control the natural frequency of the two wholes to be the same, or the natural frequency of the two wholes to differ by less than 5%. At this time, when the linear actuator receives the electrical signal drive, it controls the conversion frequency of the alternating current to achieve the same or close natural frequency as the aforementioned two wholes, so as to achieve resonance, thereby enabling the two wholes to vibrate at the same frequency, and thus realize the function of the product to which the linear actuator is applied.

[0044] In a preferred embodiment, to ensure that the natural frequencies of the two components are the same or differ by less than 5%, this invention provides two specific implementation methods. The first implementation method includes a first elastic connecting part and a second elastic connecting part, which are respectively connected to the magnet assembly mounting part on the corresponding side. (See [link to relevant documentation]). Figure 2 As shown, with Figure 2Taking the direction of the mounting frame 200 as an example, the two ends of the magnet assembly mounting part on the left side along its length are the first elastic connection parts, and the two ends of the magnet assembly mounting part on the right side along its length are the second elastic connection parts. The number of output shafts 421 on the drive arm 400 of the magnet assembly mounting part connected to the first elastic connection part is greater than the number of output shafts 421 on the drive arm 400 of the magnet assembly mounting part connected to the second elastic connection part. The first elastic connection part includes a first elastic support part 240, and the second elastic connection part includes a second elastic support part 250. The wall thickness of the first elastic support part 240 is greater than the wall thickness of the second elastic support part 250, and the wall thickness of the first elastic support part 240 is 10%-30% greater than the wall thickness of the second elastic support part 250. That is, it can be understood that the wall thickness d of the second elastic support part 250 multiplied by (10%-30%) and then added to the wall thickness d of the second elastic support part 250 equals the wall thickness of the first elastic support part 240. The length of the first elastic connection at both ends of the magnet assembly mounting part on the left is the same as the length of the second elastic support part 250. The square root of the ratio of the elastic coefficient of the first elastic connection at both ends of the magnet assembly mounting part on the left to the mass of the whole formed by the magnet assembly mounting part, the drive arm 400 on the magnet assembly mounting part, the output shaft 421, the load, and the first elastic connection at both ends divided by 2π is F1. The square root of the ratio of the elastic coefficient of the second elastic connection at both ends of the magnet assembly mounting part on the right to the mass of the whole formed by the magnet assembly mounting part, the drive arm 400 on the magnet assembly mounting part, the output shaft 421, the load, and the second elastic connection at both ends divided by 2π is F2. F1 = F2. F1 and F2 both represent natural frequencies, so that the natural frequencies of the two wholes are the same, or so that F1 and F2 satisfy the relationship |F1-F2|≤0.05×min(F1,F2), where min(F1,F2) represents the smaller value of F1 and F2, so that the natural frequencies of the two wholes differ by less than five percent. As can be seen, in this embodiment, by adjusting the wall thickness of the first elastic support portion 240 and the second elastic support portion 250, the natural frequencies of the two components are made the same.

[0045] The second embodiment: The elastic connection part includes a first elastic connection part and a second elastic connection part, which are respectively connected to the magnet assembly mounting part on the corresponding side. See [link to relevant documentation]. Figure 4 As shown, with Figure 4Taking the direction of the mounting frame 200 as an example, the two ends of the length direction of the magnet assembly mounting part on the left are the first elastic connection parts, and the two ends of the length direction of the magnet assembly mounting part on the right are the second elastic connection parts. The number of output shafts 421 on the drive arm 400 of the magnet assembly mounting part connected to the first elastic connection part is greater than the number of output shafts 421 on the drive arm 400 of the magnet assembly mounting part connected to the second elastic connection part. The first elastic connection part includes a first elastic support part 240, and the second elastic connection part includes a second elastic support part 250. The length of the first elastic support part 240 is shorter than the length of the second elastic support part 250, and the length of the first elastic support part 240 is 10%-30% shorter than the length of the second elastic support part 250. This can also be understood as follows: when the length of the second elastic support part 250 is L, the length of the first elastic support part 240 is equal to [LL × (10%-30%)]. The wall thickness of the first elastic support part 240 is greater than that of the second elastic support part 250. The wall thickness of the elastic support portion 250 is the same, so that the square root of the ratio of the elastic coefficient of the first elastic connection portion at both ends of the magnet assembly mounting portion on the left to the mass of the whole formed by the magnet assembly mounting portion, the drive arm 400 on the magnet assembly mounting portion, the output shaft 421, the load, and the first elastic connection portion at both ends, divided by 2π, is F1. The square root of the ratio of the elastic coefficient of the second elastic connection portion at both ends of the magnet assembly mounting portion on the right to the mass of the whole formed by the magnet assembly mounting portion, the drive arm 400 on the magnet assembly mounting portion, the output shaft 421, the load, and the second elastic connection portion at both ends, divided by 2π, is F2. And F1=F2, F1 and F2 both represent natural frequencies, so that the natural frequencies of the two wholes are the same, or F1 and F2 satisfy the relationship |F1-F2|≤0.05×min(F1,F2), where min(F1,F2) represents the smaller value of F1 and F2, so that the natural frequencies of the two wholes differ by less than five percent. As can be seen, in this embodiment, by adjusting the lengths of the first elastic support portion 240 and the second elastic support portion 250, the natural frequencies of the two components are made the same.

[0046] As can be seen, both of the above methods achieve control of the natural frequency by simultaneously adjusting the first elastic support portion 240 of the first elastic connection portion and the second elastic support portion 250 of the second elastic connection portion.

[0047] This utility model provides three specific implementation methods for the specific structure of the mounting frame 200 in the linear driver. Implementation method one: see [link to implementation method]. Figure 5 , 611 and 14, the mounting frame 200 includes an electromagnet mounting part and two magnet assembly mounting parts. The two magnet assembly mounting parts are arranged opposite to each other and spaced apart. The electromagnet mounting part is located between the two magnet assembly mounting parts. Each magnet assembly mounting part is opposite to one end of the magnetic pole 112 of the electromagnet 100 installed in the electromagnet mounting part. Both ends of each magnet assembly mounting part are elastically connected to the corresponding end of the electromagnet mounting part through an elastic connecting part. In this embodiment, the elastic connecting part and the electromagnet mounting part are integrally formed. Specifically, the electromagnet mounting part is connected to the elastic connecting part through the connecting wall 201. The three are integrally formed, which simplifies the production process and reduces assembly errors during assembly. The first elastic connection portion further includes two third elastic support portions 220. A first elastic support portion 240 is located between the two third elastic support portions 220, and the thickness of the first elastic support portion 240 is greater than the thickness of the third elastic support portions 220 on both sides. The second elastic connection portion further includes two fourth elastic support portions 260. A second elastic support portion 250 is located between the two fourth elastic support portions 260, and the thickness of the second elastic support portion 250 is greater than the thickness of the fourth elastic support portions 260 on both sides. The first elastic support portion 240 and the second elastic support portion 250 store more elastic potential energy to help the magnet assembly 300 return to its original position. Simultaneously, the thicker first elastic support portion 240 is positioned between the two thinner third elastic support portions 220, and the thicker second elastic support portion 250 is positioned between the two thinner fourth elastic support portions 260. Between 0 and 0, the deformation of the third elastic support 220 and the fourth elastic support 260 on both sides can be made more uniform during movement, avoiding damage or breakage of either the third elastic support 220 or the fourth elastic support 260 due to large deformation; the elastic connection part also includes a first extension 213 respectively disposed on two opposite sides of the electromagnet mounting part, the first elastic connection part includes a second extension 214, the second elastic connection part includes a third extension 270, the second extension 214 and the third extension 270 are both formed by extending from the magnet assembly mounting part on the corresponding side, the first extension 213 is located between the first elastic connection part and the second elastic connection part on the same side, the first extension 213 and the second extension 214 on the same side are connected through the first elastic support 240 and the third elastic support 220, and the first extension 213 and the third extension 270 on the same side are connected through the second elastic support 250 and the fourth elastic support 260.Connecting walls 201 are provided on both opposite sides of the electromagnet mounting section. Each connecting wall 201 is connected to a first extension 213 on the same side. The portions of the first extension 213 located between the first elastic support 240 and the third elastic support 220, between the third elastic support 220 and the connecting wall 201, between the second elastic support 250 and the fourth elastic support 260, and between the fourth elastic support 260 and the connecting wall 201 are all arc-shaped 222. The portions of the second extension 214 located between the first elastic support 240 and the third elastic support 220, and between the third elastic support 220 and the adjacent stop 202, are all arc-shaped 222. The portion between (which can be understood as the portion between the third elastic support 220 and the corresponding magnet assembly 300 mounting portion) is set as an arc shape 222; the portion of the third extension 270 between the second elastic support 250 and the fourth elastic support 260 and the portion between the fourth elastic support 260 and the adjacent stop 202 (which can be understood as the portion between the fourth elastic support 260 and the corresponding magnet assembly mounting portion) is set as 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. The magnet assembly mounting section includes a side wall 230 and a pair of stops 202 extending from one side of the side wall 230 toward the electromagnet mounting section. The two stops 202 are spaced apart to provide mounting space for the magnet assembly 300. A second extension 214 and a third extension 270 are respectively located at both ends of the side wall 230 on the corresponding side of the magnet assembly mounting section, extending outward from both ends of the side wall 230. The stops 202 prevent the magnet assembly 300 from detaching from the magnet assembly mounting section during reciprocating motion. The electromagnet mounting section includes a supporting base 2011 and a pair of stops 202 disposed on the supporting base 2011. The support walls 210 are arranged at intervals, and two grooves 211 are provided at intervals on the end faces of the two support walls 210. The two grooves 211 on the two support 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 fastened in the electromagnet mounting part by the electromagnet fixing pieces 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 wall 201, and the extension part can be assembled to form the mounting frame 200 or directly formed by integral molding. In this embodiment, integral molding is used. The mounting frame 200 is made of plastic, which is beneficial to the deformation and recovery of the elastic connecting part.In this embodiment, a drive arm 400 is connected to each magnet assembly mounting part. One drive arm 400 has three output shafts 421, and the other drive arm 400 has two output shafts 421, enabling the connection and drive of five loads, such as the moving blade assembly in a hair-cutting device. Alternatively, one drive arm 400 may have two output shafts 421, and the other drive arm 400 may have one output shaft 421, enabling the connection and drive of three loads. When the output shafts 421 are mounted on the drive arm 400, they are positioned above the mounting frame 200. The drive arm 400 includes a fixing part 410 and an output shaft connecting part 420. The fixing part 410 is connected to the side wall 230 of the magnet assembly mounting part, while the output shaft connecting part 420 is bent relative to the fixing part 410 and positioned above the mounting frame 200. The output shafts 421 are mounted on the output shaft connecting part 420. See also [reference needed] in this embodiment. Figure 5 , 6 The drive arm 400 is provided with a positioning hole, and the magnet assembly mounting part is provided with a positioning protrusion. When the drive arm 400 is connected to the magnet assembly mounting part, the positioning protrusion is inserted into the positioning hole to position the drive arm 400, which facilitates 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.

[0048] This utility model also provides a second embodiment of the mounting frame 200, see [link to relevant documentation] Figure 16The mounting frame 200 in this embodiment is roughly the same as the structure in the first embodiment described above, 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 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 adapted to the shape of the top surface 2031 of the corresponding side edge 203. 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 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.

[0049] This utility model also provides a third embodiment of the mounting frame 200, see [link to documentation]. Figure 17 The mounting frame 200 in this embodiment is largely the same as the structure in the second embodiment described above, except 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 manner, better dynamic balance can be achieved, further reducing vibration. Specifically, there are two specific implementation methods for staggering the free ends of the two drive arms 400, one of which is described in [reference needed]. Figure 1-4 The free ends of the two drive arms 400 are staggered; see also... Figure 17 The output shaft 421 connection of the drive arm 400 includes a connected head 4001 and a neck 4002. The drive arm 400 is integrally connected to the magnet assembly mounting part through the neck 4002. The head 4001 is larger than the neck 4002, and the connection between the head 4001 and the neck 4002 is a concave arc 403. The concave arc 403 and the neck 4002 form a receiving groove. Part of the head 4001 of one drive arm 400 extends into the receiving groove of the other drive arm 400. At the same time, the output shafts 421 on the two drive arms 400 are located on the head 4001. The output shafts 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.

[0050] In the second and third embodiments of the above mounting frame 200, the electromagnet fixing piece 212 may not be required.

[0051] In this embodiment, see Figure 1-17 Each magnet assembly is provided with a magnet assembly 300 in each magnet assembly mounting section, and an electromagnet 100 is horizontally arranged in the electromagnet mounting section. After the magnet assembly 300 is installed in the magnet assembly mounting section, one end magnetic pole 112 of each magnet assembly 300 is opposite to that of the electromagnet 100 installed in the electromagnet mounting section. Specifically, the number of electromagnets 100 can be one or more. In this embodiment, two electromagnets 100 are used, 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 winding box 130 sleeved on the metal core 110. A coil 120 is wound around the insulating winding box 130. The metal core 110 includes at least five metal sheets 111, which are stacked to form the metal core 110. The thickness of the metal sheets 111 should be within 0.5 mm (inclusive), and the metal sheets 111 can be I-shaped. When the required thickness of the metal core 110 needs to be achieved, multiple sheets are stacked to form the core. After the metal sheets 111 are assembled together, the overall thickness of the metal core 110 is achieved. For example, when the overall thickness of the metal core 110 is required to be 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 sheets 111 is set to be within 0.5mm (inclusive) so that eddy currents will not be generated inside the metal sheets 111 when magnetization is applied, saving energy consumption and significantly reducing heat generation, without affecting the performance and energy efficiency of the linear actuator. The insulating winding box 130 is made of polymer material and its thickness does not exceed 1mm (inclusive). It is strictly forbidden for the winding box to be too thick, as this will affect the magnetic conductivity and occupy space.

[0052] In this embodiment, see Figure 1-17Each end of the electromagnet 100 has a magnet assembly 300 at each magnetic pole 112. The electromagnet 100 has two magnetic poles 112, and magnet assemblies 300 are respectively provided at the two magnetic poles 112 of the electromagnet 100. Each magnet assembly 300 includes at least two magnets 320, that is, there may be two or more magnets 320. The magnet assembly 300 also includes a magnetically conductive metal 310, and the magnets 320 are arranged along the length direction of the magnetically conductive metal 310 on the surface of the magnetically conductive metal 310. Some of the magnets 320... The side facing the electromagnet 100 is the S pole, and the side of another part of the magnets 320 facing the electromagnet 100 is the N pole. In the same magnet group 300, since some magnets 320 have the S pole facing the electromagnet 100 and the N pole facing the electromagnet 100, after the electromagnet 100 is energized, the magnetic induction between the electromagnet 100 and the magnet group 300 causes the magnet group 300 to move back and forth along the direction of the central axis B perpendicular to the electromagnet 100.

[0053] In a preferred embodiment, after all electromagnets 100 are energized, the polarities of the magnetic poles 112 at the same end of all electromagnets 100 are opposite; the magnet group 300 has three or more magnets 320, and the polarities of the sides of all magnets 320 facing the electromagnets 100 are arranged alternately with 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 polarities of the magnetic poles 112 at the same end of the two electromagnets 100 are opposite, which can be achieved by the opposite winding direction of the coil 120, thereby connecting the two electromagnets 100 in series. After 00, the current flowing through coil 120 is reversed, thus causing the polarities of the magnetic poles 112 at the same end of the two electromagnets 100 to be reversed; alternatively, the 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 coil 120, thus causing the polarities of the magnetic poles 112 at the same end of the two electromagnets 100 to be reversed. 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, such as... Figure 9The diagram illustrates the reciprocating linear motion of the magnet assembly 300 relative to the electromagnet 100 in this embodiment, with the magnet assembly 300 moving upwards in the direction of the arrow. In another embodiment, when there are two or more electromagnets 100, all electromagnets 100 are arranged side-by-side. After all electromagnets 100 are energized, the polarities of the magnetic poles 112 at the same end of all electromagnets 100 are the same. The magnet assembly 300 has three or more magnets 320, and the polarities of the sides of all magnets 320 facing the electromagnet 100 are arranged in a unit pattern of S-S-N, N-S-S, and S-N-N. The poles are arranged in units of N-N-S; for example, when there are two electromagnets 100, after AC current is applied, the magnetic poles 112 at the same end of the two electromagnets 100 are N-pole; at this time, 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-S-N, N-S-S, S-N-N, or N-N-S, such as... Figure 10 The diagram 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.

[0054] In the preferred embodiment, see Figure 11 The number of magnets 320 in the magnet assembly 300 is one more than the 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, and the central axis B of a single electromagnet 100 is located between the perpendicular lines A of the centers of two adjacent magnets 320. Preferably, the central axis B of a single electromagnet 100 coincides with the junction of two adjacent magnets 320, which can ensure 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 assembly 300 can smoothly perform reciprocating linear motion.

[0055] In the preferred embodiment, see Figure 1-17 There are two sets of magnet groups 300, each corresponding to one of the two magnetic poles 112 of the electromagnet 100. The arrangement of the magnetic poles 112 on the side of all magnets 320 facing the electromagnet 100 in one set of magnet groups 300 is the same as that in the other set. For example, each set of magnets 300 has three magnets 320. In one set, the arrangement of the magnetic poles 112 on the side of all magnets 320 facing the electromagnet 100 is S-N-S, and in the other set, the arrangement is also S-N-S. Figure 12 The diagram shows the movement directions of the two sets of magnet groups 300. In this case, the two sets of magnet groups 300 move in opposite directions. By making the movement directions of the two sets of magnet groups 300 opposite, the amplitude can be reduced, vibration can be lessened, and noise can be lowered. In another embodiment, there are two sets of magnet groups 300, each corresponding to one of the two magnetic poles 112 of the electromagnet 100. The arrangement of the magnetic poles 112 on the side of all magnets 320 facing the electromagnet 100 in one set of magnet groups 300 is the same as that in the other set. In each magnet group 300, the magnetic poles 112 of all magnets 320 facing the electromagnet 100 are arranged in opposite directions. For example, each magnet group 300 has three magnets 320. In one group, the magnetic poles 112 of all magnets 320 facing the electromagnet 100 are arranged in an S-N-S configuration, while in another group, the magnetic poles 112 of all magnets 320 facing the electromagnet 100 are arranged in an N-S-N configuration. Figure 13 As shown, this is a schematic diagram of the movement direction of the two sets of magnet groups 300. At this time, the two sets of magnet groups 300 move in the same direction.

[0056] The electromagnet 100 is horizontally arranged within the electromagnet mounting section, and the magnet assembly 300 is placed within the magnet assembly mounting section, so that the magnet assembly 300 is aligned with the corresponding magnetic poles 112 of the horizontally arranged electromagnet 100. When alternating current is applied to the electromagnet 100, the magnetic induction between the electromagnet 100 and the magnet assembly 300 causes the magnet assembly 300 to reciprocate along the direction perpendicular to the central axis of the electromagnet 100. By arranging the electromagnet 100 horizontally and placing the magnet assembly 300 to the side of the electromagnet 100 and aligned with its magnetic poles 112, lateral space can be fully utilized, significantly reducing the height of the linear actuator. This reduces the length of the product using the linear actuator, making its length and lateral proportions more harmonious and improving the product's aesthetic appearance.

[0057] This utility model also provides a specific embodiment of a hair-cutting device, including a housing, within which the aforementioned linear actuator is disposed. The load is a moving blade assembly, the number of which is consistent with the number of all output shafts 421. One moving blade assembly is connected to each output shaft 421, and the moving blade assembly reciprocates with the magnet assembly 300 under the power provided by the linear actuator. Because this hair-cutting device has the aforementioned linear actuator, all moving blade assemblies on two drive arms 400 with different numbers of loads can vibrate at the same frequency, thereby achieving effective hair cutting. Furthermore, because the hair-cutting device has the aforementioned linear actuator, it also possesses all the beneficial technical effects it brings, which will not be elaborated upon here.

[0058] 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.

[0059] 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.

[0060] 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 drive comprising a mounting frame, characterised in that: The mounting frame comprises an electromagnet mounting portion and two magnet group mounting portions, the two magnet group mounting portions are oppositely and spacedly arranged, the electromagnet mounting portion is located between the two magnet group mounting portions, the two ends of each magnet group mounting portion are elastically connected with the corresponding end of the electromagnet mounting portion through elastic connecting portions, a driving arm is connected on each magnet group mounting portion, at least one output shaft is arranged on the driving arm, the number of output shafts on one magnet group mounting portion is more than the number of output shafts on the other magnet group mounting portion, and a load is connected on each output shaft; each magnet group mounting portion, the driving arm, the output shaft, the load and the elastic connecting portions at the two ends form an integral body, the natural frequencies of the two integral bodies are the same, or the natural frequencies of the two integral bodies differ by less than 5%.

2. Linear drive according to claim 1, characterized in that The elastic connecting portions comprise a first elastic connecting portion and a second elastic connecting portion, the first elastic connecting portion and the second elastic connecting portion are connected with the magnet group mounting portions on the corresponding side respectively, and the number of output shafts on the driving arm on the magnet group mounting portion connected with the first elastic connecting portion is more than the number of output shafts on the driving arm on the magnet group mounting portion connected with the second elastic connecting portion; the first elastic connecting portion comprises a first elastic supporting portion, the second elastic connecting portion comprises a second elastic supporting portion, the wall thickness of the first elastic supporting portion is greater than the wall thickness of the second elastic supporting portion, and the wall thickness of the first elastic supporting portion is 10%-30% more than the wall thickness of the second elastic supporting portion, the length of the first elastic supporting portion is the same as the length of the second elastic supporting portion, so that the natural frequencies of the two integral bodies are the same, or the natural frequencies of the two integral bodies differ by less than 5%.

3. The linear drive of claim 1, wherein: The elastic connecting portions comprise a first elastic connecting portion and a second elastic connecting portion, the first elastic connecting portion and the second elastic connecting portion are connected with the magnet group mounting portions on the corresponding side respectively, and the number of output shafts on the driving arm on the magnet group mounting portion connected with the first elastic connecting portion is more than the number of output shafts on the driving arm on the magnet group mounting portion connected with the second elastic connecting portion; the first elastic connecting portion comprises a first elastic supporting portion, the second elastic connecting portion comprises a second elastic supporting portion, the length of the first elastic supporting portion is shorter than the length of the second elastic supporting portion, and the length of the first elastic supporting portion is 10%-30% shorter than the length of the second elastic supporting portion, the wall thickness of the first elastic supporting portion is the same as the wall thickness of the second elastic supporting portion, so that the natural frequencies of the two integral bodies are the same, or the natural frequencies of the two integral bodies differ by less than 5%.

4. Linear drive according to claim 2 or 3, characterized in that: The elastic coefficient of the first elastic connecting part at both ends of one magnet group mounting part and the square root of the ratio of the mass of the whole formed by the magnet group mounting part, the driving arm, the output shaft, the load, and the first elastic connecting part at both ends thereof divided by 2Π is F1, the elastic coefficient of the second elastic connecting part at both ends of the other magnet group mounting part and the square root of the ratio of the mass of the whole formed by the magnet group mounting part, the driving arm, the output shaft, the load, and the second elastic connecting part at both ends thereof divided by 2Π is F2, and F1=F2 or |F1-F2|≤0.05×min(F1, F2), wherein min(F1, F2) represents the smaller value of F1 and F2.

5. Linear drive according to claim 2 or 3, characterized in that: The first elastic connecting part further comprises third elastic supporting parts, the first elastic supporting part is located between the two third elastic supporting parts, and the thickness of the first elastic supporting part is greater than the thickness of the third elastic supporting parts on both sides thereof. The second elastic connecting part further comprises fourth elastic supporting parts, the second elastic supporting part is located between the two fourth elastic supporting parts, and the thickness of the second elastic supporting part is greater than the thickness of the fourth elastic supporting parts on both sides thereof.

6. The linear drive of claim 5, characterized in that: The elastic connecting part further comprises first extending parts arranged on opposite sides of the electromagnet mounting part, the first elastic connecting part comprises a second extending part, the second elastic connecting part comprises a third extending part, the second extending part and the third extending part are formed by extending from the corresponding magnet group mounting part, the first extending part is located between the first elastic connecting part and the second elastic connecting part on the same side, the first extending part and the second extending part on the same side are connected through the first elastic supporting part and the third elastic supporting part, and the first extending part and the third extending part on the same side are connected through the second elastic supporting part and the fourth elastic supporting part.

7. The linear drive of claim 6, characterized in that: Connecting walls are arranged on opposite sides of the electromagnet mounting part, each connecting wall is connected with the first extending part on the same side, and the portions of the first extending part located between the first elastic supporting part and the third elastic supporting part, between the third elastic supporting part and the connecting wall, between the second elastic supporting part and the fourth elastic supporting part, and between the fourth elastic supporting part and the connecting wall are arranged in a circular arc shape. The portions of the second extending part located between the first elastic supporting part and the third elastic supporting part and between the third elastic supporting part and the magnet group mounting part are arranged in a circular arc shape. The portions of the third extending part located between the second elastic supporting part and the fourth elastic supporting part and between the fourth elastic supporting part and the magnet group mounting part are arranged in a circular arc shape.

8. Linear drive according to any of claims 1-3, characterized in that: A magnet group is arranged in each magnet group mounting part, and an electromagnet is arranged horizontally in the electromagnet mounting part, each magnet group is opposite to one end magnetic pole of the electromagnet arranged in the electromagnet mounting part after being mounted in the magnet group mounting part. The number of output shafts on one driving arm is three, and the number of output shafts on the other driving arm is two; or, the number of output shafts on one driving arm is two, and the number of output shafts on the other driving arm is one.

9. Linear drive according to any of claims 1-3, characterized in that: Positioning holes are arranged on the driving arms, and positioning protrusions are arranged on the magnet group mounting part; when the driving arms are connected to the magnet group mounting part, the positioning protrusions are inserted into the positioning holes to position the driving arms, or the driving arms are integrally formed with the magnet group mounting part; The free ends of the two driving arms are arranged in a staggered manner or in an opposite manner.

10. A hair cutting device comprising a housing, characterized in that: A linear driver as claimed in any one of claims 1-9 is arranged in the housing, the load is a moving knife assembly, the number of moving knife assemblies is consistent with the number of all output shafts, one moving knife assembly is connected to each output shaft, and the moving knife assembly reciprocates with the magnet group under the power provided by the magnet group of the linear driver.

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