Linear driver and hair cutting device

Abstract

The invention 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 set mounting parts, and the two magnet set mounting parts are oppositely arranged at intervals; 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] The present invention relates to the technical field of linear motors, and in particular to a linear drive and a hair cutting device comprising the linear drive. Background Art

[0002] A linear actuator is a device for controlling linear displacement or force. It generates a magnetic field through the principle of electromagnetic induction, and uses this magnetic field to apply force or motion to a load, thereby achieving linear control of the load. In existing linear actuators, some linear actuators are provided with two driving arms, and the same number of output shafts are provided on the two driving arms. At this time, a single driving arm and the output shaft thereon, and the load connected to the output shaft (which may be a moving knife of a hair cutting device) form a whole. The natural frequencies of the two groups of such wholes are the same. When the linear actuator receives an electrical signal and starts working, the two groups of such wholes with the same natural frequency will have the same vibration frequency and can vibrate synchronously; however, when the number of output shafts on the two driving arms is inconsistent, the natural frequencies of the two groups of such wholes will be different. At this time, when the linear actuator receives an electrical signal and starts working, the two groups of such wholes with different natural frequencies will not be able to achieve synchronous vibration, thereby failing to achieve the function of the product to which the linear actuator is applied. For example, when the load is a hair cutting device, the moving knives on the two driving arms cannot achieve synchronous vibration. Summary of the invention

[0003] The present invention aims to solve the technical problems existing in the above-mentioned prior art and provides a linear actuator capable of making two driving arms vibrate synchronously. In addition, the present invention also provides a hair cutting device having the linear actuator.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0005] A linear actuator described in the present invention comprises a mounting frame, wherein the mounting frame comprises an electromagnet mounting portion and two magnet group mounting portions, wherein the two magnet group mounting portions are arranged opposite to each other and at intervals, wherein the electromagnet mounting portion is located between the two magnet group mounting portions, wherein both ends of each magnet group mounting portion are elastically connected to the corresponding ends of the electromagnet mounting portion through elastic connecting portions, wherein a driving arm is connected to each magnet group mounting portion, wherein at least one output shaft is arranged on the driving arm, wherein the number of output shafts on one magnet group mounting portion is greater than the number of output shafts on the other magnet group mounting portion, and wherein each output shaft is connected to a load; wherein each magnet group mounting portion, the driving arm, the output shaft, the load, and the elastic connecting portions at both ends thereof form an integral body, wherein the natural frequencies of the two integral bodies are the same, or the natural frequencies of the two integral bodies differ within 5%.

[0006] The linear actuator described in the present invention, when each magnet group mounting part forms a whole with the driving arm, output shaft, load and elastic connecting parts at both ends, and the natural frequencies of the two wholes are the same, when the linear actuator is working, all loads can vibrate at the same frequency to realize the function of the product to which the linear actuator is applied.

[0007] Furthermore, the elastic connecting part includes a first elastic connecting part and a second elastic connecting part, the first elastic connecting part and the second elastic connecting part are respectively connected to the magnet group mounting part on the corresponding side, and the number of output shafts on the driving arm on the magnet group mounting part connected to the first elastic connecting part is greater than the number of output shafts on the driving arm on the magnet group mounting part connected to the second elastic connecting part; the first elastic connecting part includes a first elastic supporting part, the second elastic connecting part includes a second elastic supporting part, the wall thickness of the first elastic supporting part is greater than the wall thickness of the second elastic supporting part, and the wall thickness of the first elastic supporting part is 10%-30% greater than the wall thickness of the second elastic supporting part, and the length of the first elastic supporting part is the same as the length of the second elastic supporting part, so that the natural frequencies of the two wholes are the same, or the natural frequencies of the two wholes differ within five percent.

[0008] Furthermore, the elastic connecting part includes a first elastic connecting part and a second elastic connecting part, the first elastic connecting part and the second elastic connecting part are respectively connected to the magnet group mounting part on the corresponding side, and the number of output shafts on the driving arm on the magnet group mounting part connected to the first elastic connecting part is greater than the number of output shafts on the driving arm on the magnet group mounting part connected to the second elastic connecting part; the first elastic connecting part includes a first elastic supporting part, the second elastic connecting part includes a second elastic supporting part, the length of the first elastic supporting part is shorter than the length of the second elastic supporting part, and the length of the first elastic supporting part is 10%-30% shorter than the length of the second elastic supporting part, and the wall thickness of the first elastic supporting part is the same as the wall thickness of the second elastic supporting part, so that the natural frequencies of the two wholes are the same, or the natural frequencies of the two wholes differ within five percent.

[0009] Furthermore, the square root of the ratio of the elastic coefficient of the first elastic connection part at both ends of one magnet group mounting part to the mass of the whole formed by the magnet group mounting part, the driving arm, the output shaft, the load, and the first elastic connection parts at both ends thereof divided by 2Π is F1, and the square root of the ratio of the elastic coefficient of the second elastic connection part at both ends of the other magnet group mounting part to the mass of the whole formed by the magnet group mounting part, the driving arm, the output shaft, the load, and the second elastic connection parts at both ends thereof divided by 2Π is F2, and 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 connecting portion further includes a third elastic supporting portion, there are two third elastic supporting portions, the first elastic supporting portion is located between the two third elastic supporting portions, and the thickness of the first elastic supporting portion is greater than the thickness of the third elastic supporting portions on both sides thereof;

[0011] The second elastic connecting portion also includes a fourth elastic supporting portion. There are two fourth elastic supporting portions. The second elastic supporting portion is located between the two fourth elastic supporting portions, and the thickness of the second elastic supporting portion is greater than the thickness of the fourth elastic supporting portions on both sides thereof.

[0012] Furthermore, the elastic connecting portion also includes a first extension portion respectively arranged on two opposite sides of the electromagnet mounting portion, the first elastic connecting portion includes a second extension portion, the second elastic connecting portion includes a third extension portion, the second extension portion and the third extension portion are both formed by extending from the magnet group mounting portion on the corresponding side, the first extension portion is located between the first elastic connecting portion and the second elastic connecting portion on the same side, the first extension portion and the second extension portion on the same side are connected through the first elastic supporting portion and the third elastic supporting portion, and the first extension portion and the third extension portion on the same side are connected through the second elastic supporting portion and the fourth elastic supporting portion.

[0013] Further, connecting walls are respectively arranged on two opposite sides of the electromagnet mounting portion, each connecting wall is connected to the first extension portion on the same side, and the first extension portion located between the first elastic supporting portion and the third elastic supporting portion, the portion located between the third elastic supporting portion and the connecting wall, the portion located between the second elastic supporting portion and the fourth elastic supporting portion, and the portion located between the fourth elastic supporting portion and the connecting wall are all arranged in an arc shape;

[0014] The portion of the second extension portion 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 group mounting portion are configured in an arc shape;

[0015] The third extension portion is configured in an arc shape as a portion located between the second elastic support portion and the fourth elastic support portion and a portion located between the fourth elastic support portion and the magnet assembly mounting portion.

[0016] Further, a magnet group is arranged in each magnet group installation part, and an electromagnet is horizontally arranged in the electromagnet installation part. After the magnet group is installed in the magnet group installation part, each magnet group is opposite to one end of the electromagnet installed in the electromagnet installation part.

[0017] The number of output shafts on one of the driving arms is three, and the number of output shafts on the other driving arm is two; or the number of output shafts on one of the driving arms is two, and the number of output shafts on the other driving arm is one.

[0018] Further, a positioning hole is provided on the driving arm, and a positioning protrusion is provided on the magnet group mounting portion. When the driving arm is connected to the magnet group mounting portion, the positioning protrusion is inserted into the positioning hole to position the driving arm, or the driving arm and the magnet group mounting portion are integrally formed;

[0019] The free ends of the two driving arms are arranged alternately or oppositely.

[0020] A hair cutting device according to the present invention comprises a housing, in which the above-mentioned linear drive is arranged, the load is a movable knife assembly, the number of the movable knife assemblies is consistent with the number of all output shafts, a movable knife assembly is connected to each output shaft, and the movable knife assembly reciprocates with the magnet group under the power provided by the magnet group of the linear drive.

[0021] The hair cutting device of the present invention has the above-mentioned linear driver, so that all the movable blade assemblies on the two driving arms can vibrate at the same frequency to achieve effective hair cutting. In addition, the hair cutting device has all the beneficial technical effects brought by the above-mentioned linear actuator, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other purposes, features and advantages of the present invention will become more clear by more specific description of the preferred embodiments of the present invention shown in the accompanying drawings. The same reference numerals indicate the same parts in all the accompanying drawings, and the accompanying drawings are not deliberately scaled to the actual size, and the focus is on illustrating the main purpose of the present invention.

[0023] Figure 1 This is a perspective view of an embodiment of a linear actuator of the present invention.

[0024] Figure 2 for Figure 1 Main view.

[0025] Figure 3 This is a perspective view of an embodiment of a linear actuator of the present invention.

[0026] Figure 4 for Figure 2 Main view.

[0027] Figure 5 This is a perspective view of an embodiment of a linear actuator of the present invention.

[0028] Figure 6 for Figure 5 Schematic diagram of the decomposition.

[0029] Figure 7 It is a schematic diagram of the structure of two electromagnets.

[0030] Figure 8 Schematic diagram of the magnet group structure.

[0031] Fig. 9 Schematic diagram of the reciprocating linear motion of the magnet group relative to the electromagnet (Example 1).

[0032] Fig.10 Schematic diagram of the reciprocating linear motion of the magnet group relative to the electromagnet (Example 2).

[0033] Fig.11 A top view of the linear actuator (without the electromagnet fixing plate and the drive arm).

[0034] Fig.12 Schematic diagram of the movement direction of two groups of magnets (Example 1).

[0035] Fig.13 Schematic diagram of the movement direction of two groups of magnets (Example 2).

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

[0037] Fig.15 Schematic diagram of the drive arm structure.

[0038] Fig.16 FIG. 4 is a schematic diagram of an embodiment of a linear actuator of the present invention.

[0039] Fig.17 FIG. 4 is a schematic diagram of an embodiment of a linear actuator of the present invention. DETAILED DESCRIPTION

[0040] To facilitate understanding of the present invention, a more comprehensive description of the present invention will be given below with reference to the relevant drawings.

[0041] It should be noted that when an element is considered to be "connected" to another element, it may be directly connected to another element and integrated therewith, or there may be an intermediate element at the same time. The terms "installed", "one end", "the other end" and similar expressions used herein are for illustrative purposes only.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art. The terms used in the specification herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0043] This embodiment specifically provides an implementation of a linear actuator, see Figure 1-17 , including a mounting frame 200, the mounting frame 200 includes an electromagnet mounting part and two magnet group mounting parts, the two magnet group mounting parts are arranged oppositely and at intervals, the electromagnet mounting part is located between the two groups of magnet group mounting parts, both ends of each magnet group mounting part (the so-called "two ends" here are the two ends in the length direction of the magnet group mounting part) are elastically connected to the corresponding ends of the electromagnet mounting part through an elastic connecting part, a driving arm 400 is connected to each magnet group mounting part, and at least one output shaft 421 is arranged on the driving arm 400, the number of output shafts 421 on one magnet group mounting part is more than the number of output shafts 421 on the other magnet group mounting part, and each output shaft 421 is connected to a load; each magnet group mounting part forms a whole with the driving arm 400, the output shaft 421, the load, and the elastic connecting parts at both ends, 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 driving arm 400 are different, it will affect the mass of the whole formed by each magnet group mounting part and the driving arm 400, the output shaft 421, the load, and the elastic connecting parts at both ends. Therefore, it is necessary to control the natural frequencies of the two wholes to be the same, or the natural frequencies of the two wholes to differ within 5%. At this time, when the linear drive receives an electrical signal drive, it controls the conversion frequency of the alternating current to achieve the same or close natural frequency as the above-mentioned two wholes to achieve resonance, so that the two wholes can vibrate at the same frequency, thereby realizing the function of the product to which the linear actuator is applied.

[0044] In a preferred embodiment, in order to achieve the same natural frequency of the two bodies or the difference between the natural frequencies of the two bodies is within 5%, the present invention provides two specific implementation modes. In the first implementation mode, the elastic connection portion includes a first elastic connection portion and a second elastic connection portion, and the first elastic connection portion and the second elastic connection portion are respectively connected to the magnet group mounting portion on the corresponding side, see Figure 2 As shown, Figure 2Taking the direction of the mounting frame 200 in the figure as an example, the two ends of the length direction of the magnet group mounting part on the left are the first elastic connecting parts, and the two ends of the length direction of the magnet group mounting part on the right are the second elastic connecting parts, and the number of output shafts 421 on the driving arm 400 on the magnet group mounting part connected to the first elastic connecting part is greater than the number of output shafts 421 on the driving arm 400 on the magnet group mounting part connected to the second elastic connecting part; the first elastic connecting part includes a first elastic supporting part 240, and the second elastic connecting part includes a second elastic supporting part 250, the wall thickness of the first elastic supporting part 240 is greater than the wall thickness of the second elastic supporting part 250, and the wall thickness of the first elastic supporting part 240 is 10%-30% more than the wall thickness of the second elastic supporting part 250, that is, it can be understood that the wall thickness d of the second elastic supporting part 250 multiplied by (10%-30%) plus the wall thickness d of the second elastic supporting part 250 is the wall thickness of the first elastic supporting part 240, and the length of the first elastic supporting part 240 The length is the same as the length of the second elastic supporting part 250, so that the square root of the ratio of the elastic coefficient of the first elastic connection part at both ends of the magnet group 300 mounting part on the left to the mass of the whole formed by the magnet group mounting part, the driving arm 400 on the magnet group mounting part, the output shaft 421, the load, and the first elastic connection parts at both ends is divided by 2Π, and the square root of the ratio of the elastic coefficient of the second elastic connection part at both ends of the magnet group mounting part on the right to the mass of the whole formed by the magnet group mounting part, the driving arm 400 on the magnet group mounting part, the output shaft 421, the load, and the second elastic connection parts at both ends is divided by 2Π, 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. It can be seen that 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] Second embodiment: The elastic connection portion includes a first elastic connection portion and a second elastic connection portion, and the first elastic connection portion and the second elastic connection portion are respectively connected to the magnet assembly mounting portion on the corresponding side, see Figure 4 As shown, Figure 4Taking the direction of the mounting frame 200 in the figure as an example, the two ends of the length direction of the magnet group mounting part on the left are the first elastic connecting parts, and the two ends of the length direction of the magnet group mounting part on the right are the second elastic connecting parts, and the number of output shafts 421 on the driving arm 400 on the magnet group mounting part connected to the first elastic connecting part is greater than the number of output shafts 421 on the driving arm 400 on the magnet group mounting part connected to the second elastic connecting part; the first elastic connecting part includes a first elastic supporting part 240, and the second elastic connecting part includes a second elastic supporting part 250, the length of the first elastic supporting part 240 is shorter than the length of the second elastic supporting part 250, and the length of the first elastic supporting part 240 is 10%-30% shorter than the length of the second elastic supporting part 250. It can also be understood that when the length of the second elastic supporting part 250 is L, the length of the first elastic supporting part 240 is equal to [LL×(10%-30%)], and the wall thickness of the first elastic supporting part 240 is the same as that of the second elastic supporting part 250. The wall thickness of the elastic support part 250 is the same, so that the square root of the ratio of the elastic coefficient of the first elastic connection part at both ends of the left magnet group mounting part to the mass of the whole formed by the magnet group mounting part, the driving arm 400 on the magnet group mounting part, the output shaft 421, the load, and the first elastic connection parts at both ends divided by 2Π is F1, and the square root of the ratio of the elastic coefficient of the second elastic connection part at both ends of the right magnet group mounting part to the mass of the whole formed by the magnet group mounting part, the driving arm 400 on the magnet group mounting part, the output shaft 421, the load, and the second elastic connection parts at both ends is divided by 2Π, 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. It can be seen that in this embodiment, by adjusting the lengths of the first elastic supporting portion 240 and the second elastic supporting portion 250 , the natural frequencies of the two components are made the same.

[0046] It can be seen that the above two methods both achieve the control of the natural frequency by simultaneously adjusting the first elastic supporting portion 240 of the first elastic connecting portion and the second elastic supporting portion 250 of the second elastic connecting portion.

[0047] The present invention provides three specific implementations for the specific structure of the mounting frame 200 in the linear actuator. Implementation 1: See Figure 5 , 6, 11 and 14, the mounting frame 200 includes an electromagnet mounting portion and two magnet group mounting portions, the two magnet group mounting portions are opposite to each other and spaced apart, the electromagnet mounting portion is located between the two magnet group mounting portions, each magnet group mounting portion is opposite to one end of the magnetic pole 112 of the electromagnet 100 mounted in the electromagnet mounting portion, both ends of each magnet group mounting portion are elastically connected to the corresponding end of the electromagnet mounting portion through an elastic connecting portion, in this embodiment, the elastic connecting portion and the electromagnet mounting portion are integrally formed, specifically, the electromagnet mounting portion is connected to the elastic connecting portion through a connecting wall 201, the three are integrally formed, the production process is simplified, and the assembly error during assembly is reduced. The first elastic connection part also includes a third elastic support part 220, there are two third elastic support parts 220, the first elastic support part 240 is located between the two third elastic support parts 220, and the thickness of the first elastic support part 240 is greater than the thickness of the third elastic support parts 220 on both sides thereof; the second elastic connection part also includes a fourth elastic support part 260, there are two fourth elastic support parts 260, the second elastic support part 250 is located between the two fourth elastic support parts 260, and the thickness of the second elastic support part 250 is greater than the thickness of the fourth elastic support parts 260 on both sides thereof, more elastic potential energy is stored by the first elastic support part 240 and the second elastic support part 250 to help the magnet group 300 return to its original position, and at the same time, the thicker first elastic support part 240 is arranged between the two thinner third elastic support parts 220 and the thicker second elastic support part 250 is arranged between the two thinner fourth elastic support parts 260 0, the deformation of the third elastic supporting part 220 and the fourth elastic supporting part 260 on both sides can be made more uniform during movement, thereby preventing any of the third elastic supporting part 220 and the fourth elastic supporting part 260 from being damaged or broken due to large deformation; the elastic connecting part also includes a first extending part 213 respectively arranged on two opposite sides of the electromagnet mounting part, the first elastic connecting part includes a second extending part 214, the second elastic connecting part includes a third extending part 270, the second extending part 214 and the third extending part 270 are both formed by extending from the magnet group mounting part on the corresponding side, the first extending part 213 is located between the first elastic connecting part and the second elastic connecting part on the same side, the first extending part 213 and the second extending part 214 on the same side are connected to the third elastic supporting part 220 through the first elastic supporting part 240, and the first extending part 213 and the third extending part 270 on the same side are connected to the fourth elastic supporting part 260 through the second elastic supporting part 250.Connecting walls 201 are respectively arranged on two opposite sides of the electromagnet mounting portion, each connecting wall 201 is connected to the first extension portion 213 on the same side, and the first extension portion 213 is located between the first elastic support portion 240 and the third elastic support portion 220, between the third elastic support portion 220 and the connecting wall 201, between the second elastic support portion 250 and the fourth elastic support portion 260, and between the fourth elastic support portion 260 and the connecting wall 201, all of which are arranged in an arc shape 222; the second extension portion 214 is located between the first elastic support portion 240 and the third elastic support portion 220, and between the third elastic support portion 220 and the adjacent stopper 202 The portion between the third elastic support portion 220 and the mounting portion of the magnet group 300 on the corresponding side is set as an arc shape 222; the portion of the third extension portion 270 located between the second elastic support portion 250 and the fourth elastic support portion 260 and the portion located between the fourth elastic support portion 260 and the adjacent baffle 202 (which can be understood as being located between the fourth elastic support portion 260 and the mounting portion of the magnet group on the corresponding side) is set as an arc shape 222, and the radius of the arc shape 222 is greater than 0.5 mm (including 0.5 mm). By setting the arc shape 222 and limiting its radius, the stress at the edge of the connection can be dispersed to avoid the stress exceeding the material strength and causing cracks. The magnet group mounting portion includes a side wall 230 and a pair of stoppers 202 extending toward the electromagnet mounting portion on one side of the side wall 230. The two stoppers 202 are arranged at intervals to provide an installation space for the magnet group 300. The second extension portion 214 and the third extension portion 270 are respectively arranged at the two ends of the side wall 230 of the magnet group mounting portion on the corresponding side, and are formed by extending outward from the two ends of the side wall 230. The stoppers 202 prevent the magnet group 300 from detaching from the magnet group mounting portion during reciprocating motion. The electromagnet mounting portion includes a support bottom surface 2011 and a pair of stoppers 202 arranged on the support bottom surface 2011 in a pair. The support walls 210 are arranged at intervals, and two grooves 211 are arranged at intervals on the end faces of the two support walls 210. The two grooves 211 on the two support walls 210 correspond to each other. When the two electromagnets 100 are installed in the electromagnet installation part, the two ends of the metal core 110 are supported in the grooves 211 at the corresponding ends, and the electromagnet 100 is pressed and fastened in the electromagnet installation part by the electromagnet fixing sheet 212. Since the electromagnet installation part is fixed, the magnet group installation part will reciprocate with the magnet group 300. At this time, the elastic connection part plays a role of buffering and elastic reset. Among them, the electromagnet installation part, the magnet group installation part, the elastic connection part, the connecting wall 201 and the extension part can be assembled to form the installation frame 200, or the installation frame 200 can be directly formed by integral molding. In this embodiment, the integral molding method is adopted. The installation frame 200 is made of plastic, which is conducive to the deformation and recovery of the elastic connection part.In this embodiment, a driving arm 400 is connected to each magnet group mounting portion, wherein the number of output shafts 421 on one driving arm 400 is three, and the number of output shafts 421 on the other driving arm 400 is two, so that five loads can be connected and driven, for example, the load is a movable blade assembly in a hair cutting device, or the number of output shafts 421 on one driving arm 400 is two, and the number of output shafts 421 on the other driving arm 400 is one, so that three loads can be connected and driven; when the output shaft 421 is arranged on the driving arm 400, the output shaft 421 is located above the mounting frame 200. The driving arm 400 includes a fixing portion 410 and an output shaft connecting portion 420, wherein the fixing portion 410 is connected to the side wall 230 of the magnet group mounting portion, and the output shaft connecting portion 420 is bent relative to the fixing portion 410 and located above the mounting frame 200, and the output shaft 421 is installed on the output shaft connecting portion 420. In this embodiment, see. Figure 5 , 6 A positioning hole is provided on the driving arm 400, and a positioning protrusion is provided on the magnet group mounting portion. When the driving arm 400 is connected to the magnet group mounting portion, the positioning protrusion is inserted into the positioning hole to position the driving arm 400, which facilitates the positioning and installation of the driving arm 400. In this embodiment, the free ends of the two driving arms 400 are arranged opposite to each other.

[0048] The present invention also provides a second embodiment of the mounting frame 200, see Fig.16The mounting frame 200 in this embodiment has a substantially similar structure to that in the first embodiment, except that: in this embodiment, the electromagnet mounting portion is independently formed and then assembled with the connecting wall 201 and the elastic connecting portion. Specifically, the electromagnet mounting portion includes two symmetrical and spaced support walls 210, and 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, and the bottom surface 2011 of the connecting wall 201 is in a state of matching the shape of the top surface 2031 of the side edge 203 on the corresponding side. For example, when the top surface 2031 of the side 203 is in a concave shape, the bottom surface 2011 of the connecting wall 201 is in a convex shape, and vice versa. When the electromagnet mounting part is assembled with the connecting wall 201, the support arm of the electromagnet mounting part is inserted between the two connecting walls 201, and the top surface 2031 of the side 203 of the electromagnet mounting part abuts against the bottom surface 2011 of the connecting wall 201 on the corresponding side, and the side 203 is fastened to the connecting wall 201 on the corresponding side by a fastener, so that the electromagnet mounting part is connected to the connecting wall 201 and indirectly connected to the elastic connecting part. In addition, the difference between this embodiment and the aforementioned first embodiment is that the drive arm 400 is integrally formed with the magnet group mounting part, thereby simplifying the production process and avoiding errors caused by assembly. Specifically, the drive arm 400 includes an output shaft connecting part 420, and the output shaft connecting part 420 is directly integrally formed with the magnet group mounting part.

[0049] The present invention also provides a third embodiment of the mounting frame 200, see Fig.17 The structure of the mounting frame 200 in this embodiment is substantially the same as that in the second embodiment, except that the free ends of the two driving arms 400 in this embodiment are staggered. By staggering the two driving arms 400, better dynamic balance can be achieved, and vibration can be further reduced. Specifically, there are two specific implementations of staggering the free ends of the two driving arms 400. One of them is shown in FIG. Figure 1-4 , the free ends of the two driving arms 400 are staggered; the second one refers to Fig.17 The output shaft 421 connection portion of the driving arm 400 includes a connected head 4001 and a neck 4002. The driving arm 400 is integrally connected to the magnet group mounting portion through the neck 4002. The size of the head 4001 is larger than the size of the neck 4002, and the connection between the head 4001 and the neck 4002 is a concave arc 403. A receiving groove is formed by the concave arc 403 and the neck 4002, wherein the head 4001 of the driving arm 400 on one side partially extends into the receiving groove of the driving arm 400 on the other side. At the same time, the output shafts 421 on the two driving arms 400 are located on the head 4001, and the output shafts 421 on the heads 4001 of the two driving arms 400 are arranged side by side, so that the free ends of the two driving arms 400 are in a staggered state.

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

[0051] In this embodiment, see Figure 1-17 A magnet group 300 is arranged in each magnet group mounting part, and an electromagnet 100 is horizontally arranged in the electromagnet mounting part. After the magnet group 300 is installed in the magnet group mounting part, each magnet group 300 is opposite to one end magnetic pole 112 of the electromagnet 100 installed in the electromagnet mounting part. Specifically, the number of electromagnets 100 can be one or more. In the present embodiment, two electromagnets 100 are used to generate two pairs of magnetic field combinations, thereby increasing the stability of the reciprocating motion of the magnet group 300 and increasing the magnetic force, while also saving costs. The electromagnet 100 includes a metal core 110 and an insulating winding box 130 sleeved on the metal core 110, and a coil 120 is wound around the insulating winding box 130, wherein the metal core 110 includes at least five metal sheets 111, and multiple metal sheets 111 are stacked to form the metal core 110, and the thickness of the metal sheet 111 must be within 0.5 mm (including 0.5 mm), and the metal sheet 111 can be in an I shape; when the required thickness of the metal core 110 needs to be achieved, multiple sheets need to be stacked to form the metal core 110. 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 3 mm, if a 0.3 mm metal sheet 111 is used, ten metal sheets 111 are required, and if a 0.5 mm metal sheet 111 is used, six metal sheets 111 are required; in addition, the thickness of the metal sheet 111 is set to be within 0.5 mm (including 0.5 mm). When magnetism is passed, eddy currents will not be generated inside the metal sheet 111, which saves energy and greatly reduces heat generation, and does not affect 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 1 mm (including 1 mm). If the absolute winding box is too thick, it will affect the magnetic conductivity effect and occupy space.

[0052] In this embodiment, see Figure 1-17, a magnet group 300 is respectively arranged at each end of the magnetic pole 112 of the electromagnet 100, the electromagnet 100 has two magnetic poles 112, and a magnet group 300 is respectively arranged at the two magnetic poles 112 of the electromagnet 100; the magnet group 300 includes at least two magnets 320, that is, the magnets 320 can be two or more than two, and the magnet group 300 also includes a magnetic conductive metal 310, and the magnets 320 are arranged on the surface of the magnetic conductive metal 310 along the length direction of the magnetic conductive metal 310; some of the magnets 320 The side facing the electromagnet 100 is the S pole, and the side facing the electromagnet 100 of another part of the magnets 320 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, when the electromagnet 100 is energized, the magnetic induction effect 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.

[0053] In a preferred embodiment, after all the electromagnets 100 are energized, the polarities of the magnetic poles 112 at the same end of all the electromagnets 100 are opposite; the magnet group 300 has more than three magnets 320, and the polarities of the sides of all the magnets 320 in the magnet group 300 facing the electromagnet 100 are arranged alternately according to the S pole and the N pole; for example, when there are two electromagnets 100, after the alternating current is passed, at the same end of the two electromagnets 100, the polarity of the magnetic pole 112 of one electromagnet 100 is the N pole, and the polarity of the magnetic pole 112 of the other electromagnet 100 is the S pole; the polarities of the magnetic poles 112 at the same end of the two electromagnets 100 are opposite, and the winding directions of the coils 120 are opposite, so that the two electromagnets 100 connected in series are connected. 00, the current flowing through the coil 120 is opposite, thereby making the polarity of the magnetic pole 112 at the same end of the two electromagnets 100 opposite; it can also be that the two electromagnets 100 are arranged in parallel, so that the positive and negative poles of the two are connected in opposite directions, thereby causing the current to flow in the coil 120 in opposite directions, thereby making the polarity of the magnetic pole 112 at the same end of the two electromagnets 100 opposite, but this structure requires that the two electromagnets 100 be controlled separately, which increases the structural complexity of the control circuit and improves the manufacturing cost of the linear actuator; 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 pole-N pole-S pole or N pole-S pole-N pole, such as Fig. 9As shown, a schematic diagram of the action of the magnet group 300 in this embodiment in reciprocating linear motion relative to the electromagnet 100 is shown, and the magnet group 300 moves upward in the direction of the arrow. In another embodiment, when there are more than two electromagnets 100, all electromagnets 100 are arranged side by side, and after all electromagnets 100 are powered on, the polarity of the magnetic poles 112 at the same end of all electromagnets 100 is the same; the magnet group 300 has more than three magnets 320, and the polarity of the side of all magnets 320 in the magnet group 300 facing the electromagnet 100 is arranged in a unit arrangement of S pole-S pole-N pole, N pole-S pole-S pole, or S pole-N pole-N pole. The magnet group 300 is provided with three magnets 320, and the polarities of the sides of the three magnets 320 facing the electromagnet 100 may be S-S-N, N-S-S, S-N-N, or N-N-S. Fig.10 , which shows a schematic diagram of the reciprocating linear motion of the magnet group 300 relative to the electromagnet 100 in this embodiment, and the magnet group 300 moves downward in the direction of the arrow. The above structure can ensure that the magnet group 300 can smoothly perform the reciprocating linear motion.

[0054] In a preferred embodiment, see Fig.11 The number of magnets 320 in the magnet group 300 is one more than the number of electromagnets 100, and the perpendicular line A perpendicular 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 the single electromagnet 100 coincides with the junction of two adjacent magnets 320, which can ensure that the magnetic flux generated by the single electromagnet 100 (at least more than half of the magnetic flux) passes through at least two magnets 320 on the same side at the same time, further ensuring that the magnet group 300 can smoothly perform reciprocating linear motion.

[0055] In a preferred embodiment, see Figure 1-17 There are two groups of magnet groups 300, which are respectively arranged corresponding to the two magnetic poles 112 of the electromagnet 100; the arrangement of the magnetic poles 112 of all the magnets 320 in one group of magnet groups 300 facing the electromagnet 100 is the same as the arrangement of the magnetic poles 112 of all the magnets 320 in the other group of magnet groups 300 facing the electromagnet 100. For example, each group of magnet groups 300 has three magnets 320, and the arrangement of the magnetic poles 112 of all the magnets 320 in one group of magnet groups 300 facing the electromagnet 100 is S pole-N pole-S pole, and the arrangement of the magnetic poles 112 of all the magnets 320 in the other group of magnet groups 300 facing the electromagnet 100 is also S pole-N pole-S pole, such as Fig.12 , which is a schematic diagram of the movement direction of the two magnet groups 300. At this time, the movement directions of the two magnet groups 300 are opposite. By making the movement directions of the two magnet groups 300 opposite, the amplitude can be reduced, the vibration can be reduced, and the noise can be reduced. In another embodiment, there are two magnet groups 300, which are respectively arranged corresponding to the two magnetic poles 112 of the electromagnet 100; the arrangement of the magnetic poles 112 of all the magnets 320 in one magnet group 300 facing the electromagnet 100 is different from that of the other magnet group 300. The magnetic poles 112 of all the magnets 320 in the magnet groups 300 facing the electromagnet 100 are arranged in opposite ways. For example, each magnet group 300 has three magnets 320, and the magnetic poles 112 of all the magnets 320 in one magnet group 300 facing the electromagnet 100 are arranged in an S-pole-N-pole manner, and the magnetic poles 112 of all the magnets 320 in the other magnet group 300 facing the electromagnet 100 are arranged in an N-pole-S-pole manner. Fig.13 , which is a schematic diagram of the movement directions of the two magnet groups 300 . At this time, the movement directions of the two magnet groups 300 are the same.

[0056] The electromagnet 100 is arranged horizontally in the electromagnet installation part, and the magnet group 300 is arranged in the magnet group installation part, so that the magnet group 300 is opposite to the magnetic pole 112 at the corresponding end of the horizontally arranged electromagnet 100. After the electromagnet 100 is supplied with alternating current, the magnetic induction effect of the electromagnet 100 and the magnet group 300 can cause the magnet group 300 to reciprocate along the direction perpendicular to the central axis of the electromagnet 100. By arranging the electromagnet 100 horizontally and arranging the magnet group 300 on the side of the electromagnet 100 and opposite to the magnetic pole 112 of the electromagnet 100, the lateral space can be fully utilized, the height of the linear actuator is greatly reduced, the length of the product using the linear actuator is reduced, the proportion of the length direction and the lateral direction is coordinated, and the aesthetic appearance of the product is improved.

[0057] The present invention also provides a specific embodiment of a hair cutting device, including a housing, in which the above-mentioned linear drive is arranged, and the load is a moving knife assembly, the number of which is consistent with the number of all output shafts 421, and a moving knife assembly is connected to each output shaft 421, and the moving knife assembly reciprocates with the magnet group 300 under the power provided by the magnet group 300 of the linear drive. Because the hair cutting device has the above-mentioned linear drive, all the moving knife assemblies on the two driving arms 400 with different numbers of loads can vibrate at the same frequency to achieve effective hair cutting. In addition, because the hair cutting device has the above-mentioned linear actuator, it also has all the beneficial technical effects brought by it, which will not be repeated here one by one.

[0058] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0059] In the description of this specification, the description with reference to the terms "preferred embodiment", "further embodiment", "other embodiments" or "specific example" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0060] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A linear actuator, comprising a mounting frame, characterized in that: The mounting frame includes an electromagnet mounting portion and two magnet group mounting portions, the two magnet group mounting portions are arranged opposite to each other and at intervals, the electromagnet mounting portion is located between the two groups of magnet group mounting portions, both ends of each magnet group mounting portion are elastically connected to the corresponding ends of the electromagnet mounting portion through elastic connecting portions, a driving arm is connected to 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 greater than the number of output shafts on the other magnet group mounting portion, and each output shaft is connected to a load; each magnet group mounting portion forms an integral whole with the driving arm, the output shaft, the load, and the elastic connecting portions at both ends thereon, the natural frequencies of the two integral parts are the same, or the natural frequencies of the two integral parts differ by less than 5%.

2. The linear actuator according to claim 1, characterized in that: The elastic connection part includes a first elastic connection part and a second elastic connection part, the first elastic connection part and the second elastic connection part are respectively connected to the magnet group mounting part on the corresponding side, and the number of output shafts on the driving arm on the magnet group mounting part connected to the first elastic connection part is greater than the number of output shafts on the driving arm on the magnet group mounting part connected to the second elastic connection part; the first elastic connection part includes a first elastic supporting part, and the second elastic connection part includes a second elastic supporting part, the wall thickness of the first elastic supporting part is greater than the wall thickness of the second elastic supporting part, and the wall thickness of the first elastic supporting part is 10%-30% greater than the wall thickness of the second elastic supporting part, and the length of the first elastic supporting part is the same as the length of the second elastic supporting part, so that the natural frequencies of the two wholes are the same, or the natural frequencies of the two wholes differ within five percent.

3. The linear actuator according to claim 1, characterized in that: The elastic connection part includes a first elastic connection part and a second elastic connection part, the first elastic connection part and the second elastic connection part are respectively connected to the magnet group mounting part on the corresponding side, and the number of output shafts on the driving arm on the magnet group mounting part connected to the first elastic connection part is greater than the number of output shafts on the driving arm on the magnet group mounting part connected to the second elastic connection part; the first elastic connection part includes a first elastic supporting part, and the second elastic connection part includes a second elastic supporting part, the length of the first elastic supporting part is shorter than the length of the second elastic supporting part, and the length of the first elastic supporting part is 10%-30% shorter than the length of the second elastic supporting part, and the wall thickness of the first elastic supporting part is the same as the wall thickness of the second elastic supporting part, so that the natural frequencies of the two wholes are the same, or the natural frequencies of the two wholes differ within five percent.

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

5. The linear actuator according to claim 2 or 3, characterized in that: The first elastic connecting portion further includes a third elastic supporting portion, the third elastic supporting portion has two portions, the first elastic supporting portion is located between the two third elastic supporting portions, and the thickness of the first elastic supporting portion is greater than the thickness of the third elastic supporting portions on both sides thereof; The second elastic connecting portion also includes a fourth elastic supporting portion. There are two fourth elastic supporting portions. The second elastic supporting portion is located between the two fourth elastic supporting portions, and the thickness of the second elastic supporting portion is greater than the thickness of the fourth elastic supporting portions on both sides thereof.

6. The linear actuator according to claim 5, characterized in that: The elastic connection part also includes a first extension part respectively arranged on two opposite sides of the electromagnet mounting part, the first elastic connection part includes a second extension part, the second elastic connection part includes a third extension part, the second extension part and the third extension part are both formed by extending from the magnet group mounting part on the corresponding side, the first extension part is located between the first elastic connection part and the second elastic connection part on the same side, the first extension part and the second extension part on the same side are connected through the first elastic support part and the third elastic support part, and the first extension part and the third extension part on the same side are connected through the second elastic support part and the fourth elastic support part.

7. The linear actuator according to claim 6, characterized in that: Connecting walls are respectively arranged on two opposite sides of the electromagnet mounting portion, each connecting wall is connected to the first extension portion on the same side, and the first extension portion located between the first elastic supporting portion and the third elastic supporting portion, the portion located between the third elastic supporting portion and the connecting wall, the portion located between the second elastic supporting portion and the fourth elastic supporting portion, and the portion located between the fourth elastic supporting portion and the connecting wall are all arranged in an arc shape; The portion of the second extension portion 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 group mounting portion are configured in an arc shape; The third extension portion is configured in an arc shape as a portion located between the second elastic support portion and the fourth elastic support portion and a portion located between the fourth elastic support portion and the magnet assembly mounting portion.

8. The linear actuator according to any one of claims 1 to 3, characterized in that: A magnet group is arranged in each magnet group installation part, and an electromagnet is horizontally arranged in the electromagnet installation part. After the magnet group is installed in the magnet group installation part, each magnet group is opposite to one end of the electromagnet installed in the electromagnet installation part. The number of output shafts on one of the driving arms is three, and the number of output shafts on the other driving arm is two; or the number of output shafts on one of the driving arms is two, and the number of output shafts on the other driving arm is one.

9. The linear actuator according to any one of claims 1 to 3, characterized in that: A positioning hole is provided on the driving arm, and a positioning protrusion is provided on the magnet group mounting portion. When the driving arm is connected to the magnet group mounting portion, the positioning protrusion is inserted into the positioning hole to position the driving arm, or the driving arm and the magnet group mounting portion are integrally formed; The free ends of the two driving arms are arranged alternately or oppositely.

10. A hair cutting device, comprising a housing, characterized in that: A linear drive as described in any one of claims 1 to 9 is arranged in the shell, the load is a moving knife assembly, the number of the moving knife assemblies is consistent with the number of all output shafts, a 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 drive.

Images