A vibrating planar constraint type mover unit

Abstract

The application discloses a kind of vibration plane restraint type mover unit, including first mover assembly and second mover assembly of double-layer parallel arrangement;First mover assembly has first swing frame, first permanent magnet, swing shaft and provides first elastic piece of swing recovery force;Second mover assembly has second swing frame, second permanent magnet and provides second elastic piece of swing recovery force;Two swing frames are swingably connected to fixed support portion by connecting piece;Two permanent magnets are oppositely arranged to be driven by magnetic force in opposite directions;Working part is connected to swing shaft, and the axis of swing shaft, the gravity center of working part and the action line of each elastic piece, are all located in the same working plane.The gravity center and force center line of each moving part are constrained in the same working plane, eliminating the force couple component perpendicular to the plane, converting multi-dimensional vibration into single plane vibration, effectively suppressing the movement perpendicular to the swing direction, reducing vibration and noise.

Description

Technical Field

[0001] This invention relates to the field of personal care small household appliance technology, specifically to a vibration plane constraint type moving part unit. Background Technology

[0002] Electric hair clippers are hair trimming tools powered by electromagnetic or electric motors and are widely used in the personal care industry. Electric hair clippers typically consist of a moving unit, a stator unit, a blade unit, and a housing. The stator unit generates an alternating magnetic field through a coil and an iron core. Under the influence of this magnetic field, the moving unit reciprocates and drives the moving blade to oscillate at a high frequency relative to the stationary blade, thus cutting the hair.

[0003] To achieve dynamic balance and reduce vibration, various improvement schemes have been proposed in the prior art. A common approach is to adopt a dual-mover counter-rotating oscillating structure, which involves setting two sets of mover units side by side with the permanent magnets having opposite polarities. Under the action of electromagnetic force, the two sets of mover units exhibit alternating oscillations in opposite directions. The linkage between the two sets of mover units is achieved through a balancing rocker arm, thereby canceling out their inertial forces to a certain extent. For example, patent document CN119681967A discloses a structure that integrates a mover unit, a stator unit, and a cutter head unit on the same bracket. Its mover units have two sets, side by side with the permanent magnets having opposite polarities, and the linkage between the two sets of mover units is achieved through a balancing rocker arm.

[0004] However, the aforementioned existing technologies have the following shortcomings: First, the vibration direction is complex, resulting in a poor user experience. In the dual-mover counter-oscillating structure, although the inertial forces of the two sets of mover units in the reciprocating motion direction are partially canceled out, the centers of gravity of each moving component (including the two mover units, elastic elements, moving blades, etc.) and the lines of action of the restoring forces generated by each elastic element are not in the same geometric plane. This generates torque about the normal direction of that plane during operation, causing the machine to produce multi-dimensional composite vibrations. That is, in addition to the expected horizontal oscillation direction, a surging component perpendicular to the plane of the oscillation direction is also generated, resulting in a poor grip and increased noise. For the single-swing rod structure, the same problem exists where the centers of gravity and forces of the moving components such as the swing rod, magnet, and moving blade deviate from the same plane, generating additional torques.

[0005] Second, dynamic center of gravity drift exacerbates vibration. During the high-frequency oscillation of the moving tool with the pendulum axis, the moving tool itself, as a reciprocating mass, will generate additional torque if its center of gravity is not on the extension line of the pendulum axis. At the same time, the dynamic center of gravity of the entire system drifts periodically, further generating additional vibration excitation.

[0006] Third, the layout of existing counterweight schemes is unreasonable. Although existing technologies include counterweights on the drive components to balance the inertia of reciprocating motion, such counterweights are usually placed on any side or both ends of the drive components, only for the purpose of mass matching. They do not have a unified planar layout design for the counterweights, the center of gravity of the moving parts such as the mover unit and the elastic element, and the line of action of the restoring force. The vibration component perpendicular to the expected swing direction still exists, and the vibration reduction effect is limited.

[0007] Therefore, it is necessary to provide an electric push-shear subunit that can effectively constrain the vibration of moving parts within a single plane and significantly reduce vertical movement. Summary of the Invention

[0008] To reduce motor vibration and noise, this invention provides a vibration plane constrained type mover unit.

[0009] The technical solution adopted in this invention is as follows: A vibration plane-constrained mover unit includes a first mover assembly and a second mover assembly arranged in parallel on two layers; the first mover assembly has a first swing frame, a first permanent magnet, and a first elastic element for providing swing restoring force to the first swing frame, and the first swing frame is provided with a swing shaft for driving the reciprocating motion of the working part; the second mover assembly has a second swing frame, a second permanent magnet, and a second elastic element for providing swing restoring force to the second swing frame; the first swing frame and the second swing frame are oscillatingly connected to a fixed support part through a connector; the first permanent magnet and the second permanent magnet are arranged with opposite polarities so as to be driven by magnetic forces in opposite directions in an external alternating magnetic field; the working part is connected to the swing shaft, and the axis of the swing shaft, the center of gravity of the working part, the line of action of the restoring force applied by the first elastic element to the first swing frame, and the line of action of the restoring force applied by the second elastic element to the second swing frame are all located in the same working plane.

[0010] Preferably, the connecting member is an elastic connecting member, and the two ends of the first swing frame and the second swing frame are respectively connected to the fixed support part through the elastic connecting member; the first elastic member and the second elastic member are both cylindrical springs, and the line of action of the restoring force is the axis of the cylindrical spring.

[0011] Preferably, both the first swing frame and the second swing frame are T-shaped; the first swing frame has a first crossbeam and a first longitudinal beam, the first permanent magnet is installed on the side of the first crossbeam facing the stator unit, the two connecting members are connected to both ends of the first crossbeam, the first elastic member is disposed on at least one side of the first longitudinal beam, and the swing shaft is disposed at the end of the first longitudinal beam; the second swing frame has a second crossbeam and a second longitudinal beam, the second permanent magnet is installed on the side of the second crossbeam facing the stator unit, the two connecting members are connected to both ends of the second crossbeam, the front end of the second longitudinal beam is forked and its end extends into the working plane to form two extension arms, the two extension arms are respectively straddled on both sides of the first longitudinal beam, and the second elastic member acts on the two extension arms respectively.

[0012] Preferably, the ends of the two extension arms are formed with enlarged portions, which are located in the working plane and serve as counterweights; or, the ends of the two extension arms are equipped with counterweights, the center of gravity of which is located in the working plane.

[0013] Preferably, the mass of the counterweight is matched with the mass of the working part, so that when the working part reciprocates with the swing shaft, the dynamic center of gravity of the whole machine changes within a preset deviation range.

[0014] Preferably, the mass of the counterweight is matched with the mass of the working part, and the deviation between the two is within 5%; or, the ratio of the mass of the counterweight to the mass of the working part is matched with the ratio of the distance from the center of gravity of the working part to the center of gravity of the whole machine to the distance from the center of gravity of the counterweight to the center of gravity of the whole machine, and the deviation between the two is within 5%; or, the mass of the counterweight is greater than the mass of the working part and less than the theoretical mass calculated according to the distance ratio.

[0015] Preferably, the first elastic element is supported between the first longitudinal beam and the fixed support, and the second elastic element is supported between the two extended arms and the fixed support.

[0016] Preferably, a reverse linkage device is provided between the first swing frame and the second swing frame. The reverse linkage device is configured to link the first swing frame and the second swing frame so that the swing amplitude is symmetrical and the motion phase is opposite during the swing process.

[0017] Preferably, the reverse linkage device is a balancing rocker arm, the middle part of which is hinged to the fixed support part, one end of which is hinged to the first swing frame, and the other end of which is hinged to the second swing frame.

[0018] Preferably, the center of gravity of the working part is located on the extension line of the axis of the pendulum shaft.

[0019] Preferably, the connecting member is a pivot shaft, and the middle parts of the first swing frame and the second swing frame are hinged to the fixed support part through the pivot shaft; the first elastic member and the second elastic member are both torsion springs fitted on the corresponding pivot shafts, and the line of action of the restoring force is the contact thrust direction of the torsion spring foot.

[0020] Preferably, the working part is the moving blade of the hair cutting device, which is connected to the swing shaft and driven by it to reciprocate, so as to cooperate with the stationary blade to cut the hair.

[0021] The present invention has the following beneficial effects: The present invention constrains the axis of the pendulum shaft, the center of gravity of the working part, and the lines of action of the restoring force of the two elastic elements acting on the pendulum frame to the same working plane, eliminating the couple component perpendicular to this plane, transforming multidimensional vibration into pendulum vibration in a single plane, and greatly suppressing vertical sway; at the same time, the inertial force self-cancellation is achieved by using the polarity reversal setting of the double movers, and with the counterweight block whose center of gravity is located in this plane and matches the mass of the working part, the dynamic center of gravity of the whole machine remains basically unchanged during the operation, further eliminating the dynamic excitation source and significantly reducing the vibration and noise of the whole machine. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention.

[0023] Figure 2 This is an assembly diagram of an embodiment of the present invention.

[0024] Figure 3 This is a schematic diagram of the assembly of the first swing frame and the second swing frame in an embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram of the coplanar working plane in an embodiment of the present invention.

[0026] Figure 5 This is a schematic diagram of the counterweight block position arrangement in an embodiment of the present invention.

[0027] The meanings of the labels in the attached figures are as follows: 1-First swing frame, 1.1-First crossbeam section, 1.2-First longitudinal beam section; 2-First elastic element; 3-Pinus axis; 4-First permanent magnet; 5-Second swing frame, 5.1-Second crossbeam, 5.2-Second longitudinal beam, 5.3-Extension arm; 6-Second elastic element; 7-Second permanent magnet; 8-Connectors; 9-Staff; 10-Stator unit; 11-Counterweight; 12-Balanced rocker arm; 13-Surgery; 14-Still knife; 15-Standard cover; P - Working plane. Detailed Implementation

[0028] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0029] like Figures 1 to 5 As shown, an electric push shear includes a moving subunit, a stator unit 10, and a cutter head unit. The moving subunit is movably mounted on a fixed support. The fixed support is the fixed base on which the moving subunit is attached during operation, and can refer to the bracket 9, the iron core of the stator unit 10, the bracket cover 15 fixed to the bracket 9, or the outer casing of the entire machine. The connecting member 8 oscillates the first swing frame 1 and the second swing frame 5 to the fixed support. Its specific form can be selected from an elastic connecting member or a pivot shaft depending on the movement mode of the moving subunit.

[0030] like Figures 1 to 3 As shown, in this embodiment, the connector 8 is an elastic connector, specifically a stacked spring sheet, or a torsion spring sheet, elastic metal wire or other flexible connecting element with elastic deformation capability.

[0031] The mover unit includes a first mover assembly and a second mover assembly arranged in two parallel layers. The first mover assembly has a first swing frame 1 and first elastic members 2 acting on both sides of the swing direction. The first swing frame 1 is provided with a swing shaft 3 and a first permanent magnet 4. The swing shaft 3 is used to drive the moving blade 13 to reciprocate. The second mover assembly has a second swing frame 5 and second elastic members 6 acting on both sides of the swing direction. The second swing frame 5 is provided with a second permanent magnet 7. The two ends of the first swing frame 1 and the second swing frame 5 are respectively connected to the fixed support part through elastic connectors. The first permanent magnet 4 and the second permanent magnet 7 are arranged opposite to the stator unit 10, and the polarities of the first permanent magnet 4 and the second permanent magnet 7 are opposite, so that they are driven by magnetic forces in opposite directions in the alternating magnetic field generated by the stator unit 10.

[0032] The axis of the swing shaft 3, the center of gravity of the moving blade 13, and the lines of action of the restoring forces applied to the corresponding swing frame by each of the first elastic elements 2 and the second elastic elements 6 are all located within the same working plane P. Both the first elastic element 2 and the second elastic element 6 are cylindrical springs, and the axis of the cylindrical spring is the line of action of the restoring force. Through this arrangement, the two moving parts are driven by opposite magnetic forces in an alternating magnetic field, achieving staggered swinging. The inertial forces generated by each moving part are constrained within this plane, with no couple component perpendicular to this plane, and the surging component perpendicular to the working plane P is effectively suppressed.

[0033] like Figures 2 to 3 As shown, both the first swing frame 1 and the second swing frame 5 are T-shaped. The first swing frame 1 has a first crossbeam 1.1 and a first longitudinal beam 1.2. A first permanent magnet 4 is installed on the side of the first crossbeam 1.1 facing the stator unit 10. Two connecting pieces 8 are respectively connected to the two ends of the first crossbeam 1.1. A first elastic member 2 is respectively disposed on both sides of the first longitudinal beam 1.2. A swing shaft 3 is disposed at the end of the first longitudinal beam 1.2. The second swing frame 5 has a second crossbeam 5.1 and a second longitudinal beam 5.2. A second permanent magnet 7 is installed on the side of the second crossbeam 5.1 facing the stator unit 10. Two connecting pieces 8 are respectively connected to the two ends of the second crossbeam 5.1. The front end of the second longitudinal beam 5.2 is forked and its end extends into the working plane P, forming two extension arms 5.3. The two extension arms 5.3 are respectively straddled on both sides of the first longitudinal beam 1.2, and the second elastic member 6 acts on the two extension arms 5.3 respectively. Specifically, the first elastic element 2 is supported between the first longitudinal beam 1.2 and the fixed support, and the second elastic element 6 is supported between the two extension arms 5.3 and the fixed support. The first swing frame 1 and the second swing frame 5 can be integrally molded using injection molding, and the material can be selected from engineering plastics with good rigidity and dimensional stability, such as polyoxymethylene, nylon, or liquid crystal polymer.

[0034] The aforementioned T-shaped structure creates clear functional zones between the crossbeam and longitudinal beam sections of the two swing frames. The crossbeam section carries the magnetic circuit function and provides elastic support, while the longitudinal beam section carries the swing drive and elastic reset. Based on this layout, the two extension arms 5.3 of the second swing frame 5 can straddle both sides of the first longitudinal beam section 1.2, allowing the two moving parts to form a staggered nesting arrangement in space. This ensures both the compactness of the double-layer parallel arrangement and that the lines of action of the restoring forces of the two second elastic elements 6 are located within the working plane P, eliminating the need to increase the overall size of the machine to meet the coplanar layout requirements. At the same time, the first permanent magnet 4 and the second permanent magnet 7 are directly opposite the stator unit 10, resulting in a short magnetic circuit, low magnetic leakage, and high electromagnetic energy conversion efficiency.

[0035] like Figures 2 to 3As shown, enlarged portions are formed at the ends of the two extension arms 5.3, which are located within the working plane P and serve as counterweights 11; alternatively, counterweights 11 are mounted at the ends of the two extension arms 5.3, with the center of gravity of the counterweights 11 located within the working plane P. The counterweights 11 can be made of a high-density metal material such as copper alloy or tungsten alloy to achieve the required mass in a smaller volume. The mass of the counterweights 11 matches the mass of the moving blade 13, ensuring that the dynamic center of gravity of the entire system remains essentially unchanged as the moving blade 13 reciprocates with the swing shaft 3.

[0036] like Figures 1 to 2 As shown, the moving part assembly, supported by two sets of elastic connectors 8 and the first elastic element 2 and the second elastic element 6, constitutes a spring-mass resonant system, and its operating frequency is set near the system's natural frequency. The counterweight 11, as a mass participating in the resonance, generates an inertial force opposite to that of the moving blade 13 during its swing. The two forces cancel each other out, thus keeping the dynamic center of gravity of the entire system essentially unchanged. At the same time, in the resonant state, the system's inertial force and elastic restoring force are naturally balanced, and the electromagnetic driving force only needs to supplement the energy consumed by the damping. Therefore, the setting of the counterweight 11 does not increase power consumption.

[0037] The mass of counterweight 11 can be set in three ways.

[0038] Method 1: Static balance mode. For example... Figure 5 As shown, the mass m2 of the counterweight 11 is equal to or approximately equal to the mass m1 of the moving blade 13, i.e., m2≈m1, and the parameter can be adjusted within ±5%. In this mode, the masses of the counterweight 11 and the moving blade 13 are equal, and the torques of their gravity on the center of gravity O of the electric push shear machine are balanced, keeping the center of gravity O of the electric push shear machine in the designed position under static conditions. This design is intuitive, requiring no precise calculation of the lever arms and dynamic inertial forces of each component; static balance can be achieved simply by ensuring mass matching, facilitating rapid matching and suitable for conventional structural layouts.

[0039] Method 2: Dynamic balancing mode. For example... Figure 5As shown, the ratio of the mass m2 of the counterweight 11 to the mass m1 of the moving blade 13 is equal to or approximately equal to the ratio of the distance L1 from the center of gravity O1 of the moving blade 13 to the center of gravity O of the entire electric hair clipper to the distance L2 from the center of gravity O2 of the counterweight 11 to the center of gravity O of the entire electric hair clipper, that is, m2:m1≈L1:L2, and the parameters can also be adjusted within a range of ±5%. When this relationship is satisfied, the moments generated by the inertial forces of the moving blade 13 and the counterweight 11 during reciprocating oscillation about the center of gravity O of the entire electric hair clipper always cancel each other out, so that the center of gravity O of the entire electric hair clipper remains stationary during the dynamic process. Through accurate calculation and matching of the inertial forces of each moving component, this method achieves dynamic balance throughout the entire working process, and is suitable for applications with higher requirements for vibration damping performance. The center of gravity O of the entire electric hair clipper is usually located near the center of the grip part. When the center of gravity O of the entire electric hair clipper remains stationary during the dynamic process, the vibration received at the user's gripping part is the smallest, resulting in the best hand feel.

[0040] Mode 3: Comprehensive balance mode. As Figure 5 shown (generally L1>L2), the mass m2 of the counterweight 11 is between the mass values determined by Mode 1 and Mode 2, that is, m1<m2<(L1 / L2)m1. In this mode, m2 takes an intermediate value between the two, and its physical meaning is that both static center of gravity offset and dynamic inertia moment are partially suppressed, instead of setting a certain parameter to zero completely. Specifically, when m2 is within this interval, the static center of gravity offset caused by the mass difference between the moving blade 13 and the counterweight 11 is smaller than that in the dynamic balance of Mode 2, and the residual moment of the inertial forces of the two about the center of gravity O of the entire electric hair clipper is smaller than that in the static balance of Mode 1, achieving a balance and trade-off between static balance and dynamic balance performance. This mode is particularly applicable to situations where the installation space of the counterweight is limited and cannot accommodate the large-mass counterweight required in Mode 2, or when the product is cost-sensitive and it is not desired to change the overall shape due to the excessively large counterweight. By reasonably selecting the specific value of m2 within the interval (such as taking the median of the interval or determining it according to the weighted proportion), designers can flexibly adjust between static stability and dynamic vibration suppression according to the actual requirements of the product. To further improve the effect of the comprehensive balance mode, L1 can be made as close to L2 as possible by adjusting the lengths of the two extending arms 5.3 or the installation position of the counterweight 11. When L1 and L2 tend to be close, the mass value intervals of the three modes narrow and converge. No matter which of the above counterweight methods is adopted, both static and dynamic balance can be achieved with a small counterweight mass, which is beneficial to the miniaturization and lightweight design of the whole machine. In actual development, the ratio of L1 to L2 can be used as a design variable for comprehensive optimization according to the feasible range of assembly space and center of gravity layout, so as to find the optimal counterweight scheme under the constraint of the exposed position of the working part. As an engineering trade-off between Mode 1 and Mode 2, Mode 3 relaxes the stringent requirements on the mass accuracy and spatial layout of the counterweight on the premise of ensuring a significant vibration damping effect, and improves the design flexibility and process manufacturability of the product.

[0041] like Figures 1 to 2 As shown, the first elastic element 2 is supported between the first longitudinal beam 1.2 and the fixed support, and the second elastic element 6 is supported between the two extension arms 5.3 and the fixed support. Within the working plane P, the two first elastic elements 2 are located on either side of the first longitudinal beam 1.2, and the two second elastic elements 6 are located on the outer sides of the two extension arms 5.3. When the mover assembly deviates from its equilibrium position, the elastic element on one side is compressed, and the elastic element on the other side is stretched or reset, with both providing a restoring force. Using cylindrical springs for the elastic elements simplifies design and assembly, reduces manufacturing costs, and facilitates adjustment of the system's resonant frequency and oscillation amplitude by replacing springs with different elastic coefficients. The elastic elements can also be in the form of leaf springs or gas springs, as long as the line of action of their restoring force lies within the working plane P.

[0042] like Figure 2 and Figure 4 As shown, a balancing rocker arm 12 is also provided between the first swing frame 1 and the second swing frame 5. In this embodiment, the fixed support is specifically a bracket 9, on which a bracket cover 15 is fixed. The bracket cover 15 is made of metal, and part of its edge is bent inward to form a hinge seat. The middle part of the balancing rocker arm 12 is hinged to the hinge seat, one end of the balancing rocker arm 12 is hinged to the first swing frame 1, and the other end is hinged to the second swing frame 5. As a specific implementation of the reverse linkage device, the balancing rocker arm 12 links the movements of the two moving components, making their swing amplitudes symmetrical and their movement phases opposite during the swing process, further ensuring the symmetry of their swing amplitudes and the consistency of their opposite movement phases. The hinge holes at both ends of the balancing rocker arm 12 are elongated holes to adapt to the linear swing trajectory of the hinge point while transmitting the swing, compensating for the displacement caused by the difference in the hinge point trajectory, ensuring the smoothness and reliability of the movement, and avoiding jamming due to differences in the movement trajectory. The setting of the balancing rocker arm 12 increases the rigidity constraint of the system, making the staggered swing of the two moving components more stable and synchronized.

[0043] like Figure 1 and Figure 2As shown, the cutter head unit consists of a moving blade 13 and a stationary blade 14. The moving blade 13 is driven to reciprocate by a swing shaft 3 and works in conjunction with the stationary blade 14 to cut hair. Both the moving blade 13 and the stationary blade 14 are comb-shaped and overlap in surface contact. Driven by the swing shaft 3, the moving blade 13 slides back and forth relative to the stationary blade 14, thereby cutting the hair that extends between the teeth. The stationary blade 14 is mounted on the head of the bracket 9, with its front end face in contact with the rear end face of the moving blade 13. The center of gravity of the moving blade 13 is set on the extended axis of the swing shaft 3, eliminating the additional torque generated by the center of gravity deviating from the axis during the swinging process, making the reciprocating motion of the moving blade 13 smoother and further reducing the vibration excitation source. The position of the center of gravity of the moving blade 13 can be adjusted by adjusting the shape of the moving blade 13 or by adding local counterweights to the moving blade 13. Before use, the cutting interval can be adjusted by adjusting the position of the stationary blade 14 relative to the moving blade 13 to obtain different cutting lengths.

[0044] As another parallel implementation, the moving unit can also adopt a rotary hinged support structure. Based on the solution in patent document CN203357478U, the connecting member 8 is a pivot shaft. The middle parts of the first swing frame 1 and the second swing frame 5 are hinged to the fixed support via a pivot shaft, allowing each swing frame to swing freely around the pivot shaft. The first elastic member 2 and the second elastic member 6 are both torsion springs fitted onto the corresponding pivot shafts. The two torsion spring legs of the torsion springs respectively abut against the corresponding swing frame and the fixed support, providing a swing restoring torque for the swing frame. When the swing frame deviates from its equilibrium position under the drive of an external alternating magnetic field, the torsion spring is twisted, generating a restoring torque that drives the swing frame to reset. The torsion spring legs of the first elastic member 2 acting on the actual thrust direction line of the first swing frame 1, the torsion spring legs of the second elastic member 6 acting on the actual thrust direction line of the second swing frame 5, the axis of the swing shaft 3, and the center of gravity of the moving blade 13 are all constrained within the same working plane P. For a torsion spring, although its torsional axis is perpendicular to the working plane P, the contact force between the torsion spring foot and the swing frame is a tangential force, and the direction line of this tangential force is always within the working plane P. By applying coplanar constraints to the lines of action of all the above-mentioned restoring forces, it is ensured that all restoring driving forces act within this plane during the swing, eliminating the couple component perpendicular to this plane, thereby transforming the multidimensional composite vibration into a swing vibration within a single plane, effectively suppressing the lateral movement perpendicular to the swing direction.

[0045] In addition, in the above embodiments, the first swing frame 1 and the second swing frame 5 can also be equipped with a counterweight 11. The center of gravity of the counterweight 11 is also located in the working plane P, and the mass of the counterweight 11 matches the mass of the moving blade 13, so that the dynamic center of gravity of the whole machine remains basically unchanged during the operation.

[0046] Both of the above implementation schemes (elastic support type and rotary hinge type) can achieve the core inventive concept of this invention, constraining the lines of action and centers of gravity of the restoring forces of all moving parts to the same working plane, eliminating vertical couple components, and suppressing axial movement. The two schemes can be flexibly selected according to the actual product structure and cost requirements.

[0047] Obviously, the above embodiments of the present invention are merely illustrative examples to illustrate the invention and are not intended to limit the implementation of the invention. Other obvious variations or modifications derived from the essential spirit of the invention still fall within the protection scope of the invention.

Claims

1. A vibration plane-constrained mover unit, comprising a first mover assembly and a second mover assembly arranged in two parallel layers; The first moving part assembly has a first swing frame (1), a first permanent magnet (4) and a first elastic element (2) for providing swing restoring force to the first swing frame (1). The first swing frame (1) is provided with a swing shaft (3) for driving the working part to reciprocate. The second moving part assembly has a second swing frame (5), a second permanent magnet (7), and a second elastic element (6) for providing a swing restoring force to the second swing frame (5); The first swing frame (1) and the second swing frame (5) are swayably connected to the fixed support part through the connector (8); The first permanent magnet (4) and the second permanent magnet (7) are set with opposite polarities so that they are driven by magnetic forces in opposite directions in an external alternating magnetic field; Its features are, The working part is connected to the swing shaft (3), and the axis of the swing shaft (3), the center of gravity of the working part, the line of action of the restoring force applied by the first elastic element (2) to the first swing frame and the line of action of the restoring force applied by the second elastic element (6) to the second swing frame are all located in the same working plane (P).

2. The vibration plane-constrained moving sub-unit according to claim 1, characterized in that, The connector (8) is an elastic connector. The two ends of the first swing frame (1) and the second swing frame (5) are respectively connected to the fixed support through the elastic connector. The first elastic element (2) and the second elastic element (6) are both cylindrical springs. The line of action of the restoring force is the axis of the cylindrical spring.

3. The vibration plane-constrained moving sub-unit according to claim 2, characterized in that, Both the first swing frame (1) and the second swing frame (5) are T-shaped; The first swing frame (1) has a first crossbeam (1.1) and a first longitudinal beam (1.2), the first permanent magnet (4) is installed on the side of the first crossbeam (1.1) facing the stator unit (10), the two connecting members (8) are connected to both ends of the first crossbeam (1.1), the first elastic member (2) is disposed on at least one side of the first longitudinal beam (1.2), and the swing shaft (3) is disposed at the end of the first longitudinal beam (1.2); The second swing frame (5) has a second crossbeam (5.1) and a second longitudinal beam (5.2). The second permanent magnet (7) is installed on the side of the second crossbeam (5.1) facing the stator unit (10). The two connecting members (8) are connected to the two ends of the second crossbeam (5.1). The front end of the second longitudinal beam (5.2) is forked and its end extends into the working plane (P) to form two extension arms (5.3). The two extension arms (5.3) are respectively straddled on both sides of the first longitudinal beam (1.2), and the second elastic member (6) acts on the two extension arms (5.3).

4. The vibration plane-constrained moving sub-unit according to claim 3, characterized in that, The ends of the two extension arms (5.3) are formed with enlarged portions, which are located within the working plane (P) and serve as counterweights (11); or, The ends of the two extension arms (5.3) are equipped with counterweights (11), the center of gravity of which is located within the working plane (P).

5. The vibration plane-constrained moving sub-unit according to claim 4, characterized in that, The mass of the counterweight (11) is matched with the mass of the working part, so that when the working part reciprocates with the swing shaft (3), the dynamic center of gravity of the whole machine changes within a preset deviation range.

6. The vibration plane-constrained moving sub-unit according to claim 5, characterized in that, The mass of the counterweight (11) matches the mass of the working part, and the deviation between the two is within 5%; or, The ratio of the mass of the counterweight (11) to the mass of the working part is matched with the ratio of the distance from the center of gravity of the working part to the center of gravity of the whole machine to the distance from the center of gravity of the counterweight (11) to the center of gravity of the whole machine, and the deviation between the two is within 5%; or, The mass of the counterweight is greater than the mass of the working part but less than the theoretical mass calculated based on the ratio of the distances.

7. The vibration plane-constrained moving sub-unit according to claim 3, characterized in that, The first elastic member (2) is supported between the first longitudinal beam (1.2) and the fixed support, and the second elastic member (6) is supported between the two extension arms (5.3) and the fixed support.

8. The vibration plane-constrained moving sub-unit according to claim 1, characterized in that, A reverse linkage device is provided between the first swing frame (1) and the second swing frame (5). The reverse linkage device is configured to link the first swing frame (1) and the second swing frame (5) so that the swing amplitude is symmetrical and the motion phase is opposite during the swing process.

9. The vibration plane-constrained moving sub-unit according to claim 8, characterized in that, The reverse linkage device is a balance rocker arm (12), the middle part of which is hinged to the fixed support part. One end of the balance rocker arm (12) is hinged to the first swing frame (1), and the other end is hinged to the second swing frame (5).

10. The vibration plane-constrained moving sub-unit according to claim 1, characterized in that, The center of gravity of the working part is located on the extension line of the axis of the pendulum shaft (3).

11. The vibration plane-constrained moving sub-unit according to claim 1, characterized in that, The connecting member (8) is a pivot shaft, and the middle parts of the first swing frame (1) and the second swing frame (5) are hinged to the fixed support part through a pivot shaft; the first elastic member (2) and the second elastic member (6) are both torsion springs fitted on the corresponding pivot shafts, and the line of action of the restoring force is the contact thrust direction of the torsion spring foot of the torsion spring.

12. The vibration plane-constrained moving sub-unit according to claim 1, characterized in that, The working part is the moving blade (13) of the hair cutting device. The moving blade (13) is connected to the swing shaft (3) and driven by it to reciprocate, so as to cooperate with the stationary blade (14) to cut the hair.

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