High-speed reciprocating drive module

Abstract

This invention discloses a high-speed reciprocating drive module, including a drive assembly and two sets of swing frames. Specifically: ① The drive assembly consists of a motor and a slotted cam; ② The swing frame includes two sets of swing plates, spring arms, and swing arms. The swing plates are parallel to the axis of the slotted cam. The spring arms connect and support the swing plates and the drive assembly. One end of the swing arm is rigidly connected to the swing plate, and the other end is slidably engaged with a ring groove via a swing shaft; ③ The drive stroke of the slotted cam is N, and the transmission phase difference between the two swing shafts and the slotted cam is π / N, so that the swing directions of the two swing plates are opposite. The advantages are: ① The slotted cam is designed with N strokes, and the motor rotates once to drive the swing plates to complete N reciprocations, increasing the output frequency to N times that of the traditional single-stroke structure; ② The phase difference π / N makes the instantaneous velocity directions of the two swing plates opposite, canceling the inertial forces in real time, reducing vibration and noise, and improving handheld comfort. This invention achieves high-frequency, low-noise, and high-reliability reciprocating drive at low cost.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and more specifically to a high-speed reciprocating drive module. Background Technology

[0002] Some small household appliances require linear reciprocating motion to function. A common method is to use transmission mechanisms such as cams and eccentric connecting rods to convert the circular motion of the motor output shaft into reciprocating oscillations. This structure is advantageous because it is a mature product, has stable performance, and is inexpensive. However, its transmission mechanism has many parts, exhibits significant vibration and noise, and its frequency is significantly limited by the transmission mechanism. Another approach is to use a linear motor. The principle is that when a coil is energized, the magnetic force drives an oscillating frame with a permanent magnet to oscillate back and forth. Linear motors can achieve high-frequency vibration and low noise, but they are more expensive and their reliability is relatively lower.

[0003] The applicant previously filed a patent application (application number: 202510654626.2, application date: 2025.05.21) disclosing a drive module for a reciprocating shaver. Its main structure is as follows: ① A base serves as the overall support structure; ② A tilting frame is fixed to the base via spring plates at both ends, forming a frame-like main structure; ③ An output shaft is installed above the tilting frame, serving as the power output end; ④ The motor is horizontally mounted on the base and is entirely located within the aforementioned frame structure; ⑤ A cam is directly mounted on the motor's power shaft, and its circumferential surface has annular grooves of equal width and parallel normal sections; ⑥ A rocker arm is hinged to the base at its lower end, with the middle rocker arm shaft embedded in the cam's groove for linkage, and its upper end forming a motion transmission connection with the tilting frame. The components of this drive module work together. The motor drives the cam to rotate, which in turn drives the rocker arm shaft through the groove to make the rocker arm swing back and forth. This, in turn, pushes the yaw frame to produce a yaw motion under the constraint of the spring plate. Finally, the output shaft realizes the reciprocating cutting action required by the shaver. It has the advantages of fewer transmission parts, high dynamic efficiency and transmission reliability, low noise, small size and low cost.

[0004] During research and development and use, it was discovered that the oscillation frequency of the yaw bracket in the aforementioned drive module is directly related to the motor speed; that is, one rotation of the motor / cam results in one reciprocating motion of the yaw bracket. Given this characteristic, significantly increasing the vibration frequency of the yaw bracket would require a substantial increase in the motor speed, which would significantly increase costs. Summary of the Invention

[0005] To achieve high-frequency vibration in a reciprocating drive module at low cost, this invention provides a high-speed reciprocating drive module.

[0006] The technical solution adopted in this invention is as follows: A high-speed reciprocating drive module includes: a drive assembly consisting of a motor and a slotted cam with multiple strokes, the slotted cam being mounted on the output shaft end of the motor, and the circumferential surface of the slotted cam having multiple strokes and parallel annular grooves with the same normal cross section; a swing frame consisting of a swing plate, a spring arm, and a swing arm, the swing plate being arranged parallel to the axis of the slotted cam, the spring arm being connected and supported between the two ends of the swing plate and the drive assembly, one end of the swing arm being rigidly connected to the swing plate, and the other end being slidably engaged with the annular groove through a swing shaft; there are two sets of the swing plate, the spring arm, the swing arm, and the swing shaft; the number of drive strokes of the slotted cam is N, and the transmission phase difference between the two swing shafts and the slotted cam is π / N, so that the swing directions of the two swing plates are opposite.

[0007] Preferably, the number of strokes of the slotted cam is 2, and the included angle of the two rocker shafts is 90°; the rocker shaft corresponding to the inner rocker plate is arranged on the vertical axis plane of the slotted cam, and the rocker shaft corresponding to the outer rocker plate is arranged on the horizontal axis plane of the slotted cam.

[0008] Preferably, the number of strokes of the slotted cam is 3, the included angle of the two rocker shafts is 60°, and they are symmetrically arranged on both sides of the vertical axis plane of the slotted cam.

[0009] Preferably, the axes of the two rocker shafts intersect perpendicularly with the axis of the slot cam.

[0010] Preferably, the contour curve of the annular groove, when unfolded on the circumferential surface of the slotted cam, is a periodic function curve, including one or more of an elliptic curve, a sine curve, a modified sine curve, or a higher-order polynomial; the contour curve contains N periodic variation segments of the same shape that are connected end to end along the circumferential direction of the slotted cam, and each periodic variation segment corresponds to one drive stroke; during the rotation of the slotted cam, the instantaneous velocities of any two points on the contour curve that are separated by π / N radians always have opposite directions in the axial component of the slotted cam.

[0011] Preferably, the two spring arms at the same end are connected to the mounting part, and the mounting part is mounted and connected to the drive assembly.

[0012] Preferably, the motor consists of a front cover, a rear cover, an outer casing, a permanent magnet, and a rotor. The slotted cam is installed at the output shaft end of the rotor. The front cover is divided into a front cover body and a front seat body, and the rear cover is divided into a rear cover body and a rear seat body. The front cover body and the rear cover body are respectively inserted into the front end and the rear end of the outer casing. The front seat body and the rear seat body extend outward along the outer casing to form the mounting positions of the two mounting parts.

[0013] Preferably, the bottom of the mounting part is provided with a threaded hole, and the front seat and the rear seat are provided with corresponding through holes. The threaded hole and the through hole are connected and fixed by screws.

[0014] Preferably, the mounting part is provided with slots on the front and rear sides, and the front and rear sides of the front seat and the rear seat are provided with buckles, which are engaged in the slots for auxiliary fixation.

[0015] Preferably, the rocker plate, the spring arm, the rocker arm and the mounting part are integrally injection molded parts, and a metal fixing plate is inlaid on the lower surface of the rocker plate.

[0016] The present invention has the following beneficial effects: 1. High-frequency reciprocating: Through the phase difference design of multi-stroke slot cam and double swing frame, the motor can drive the swing plate to complete multiple reciprocating motions in one rotation. Compared with the traditional single-stroke cam, the output frequency is greatly improved at the same speed, breaking through the transmission frequency limitation, while avoiding the cost and reliability problems caused by high-speed motors. 2. Dynamic vibration self-balancing: The two sets of swing frames are arranged with a transmission phase difference of π / N, so that the swing directions of the two swing plates are always opposite. Their inertial forces cancel each other out in the drive components, significantly reducing overall vibration and noise. It is especially suitable for high-frequency scenarios such as shavers and facial cleansing devices, and improves handheld comfort. 3. Compact structure: Spring arms and rocker arms replace traditional bearings or connecting rods, the motor end cover extends into the mounting part and is injection molded and integrated with the rocker frame, simplifying the transmission chain, reducing the number of parts, reducing assembly complexity and failure rate, and providing independent space to achieve high module integration. Attached Figure Description

[0017] Figure 1 This is a three-dimensional schematic diagram of the first embodiment of the present invention.

[0018] Figure 2 This is a front view schematic diagram of the first embodiment of the present invention.

[0019] Figure 3 This is an exploded view of the first embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of the swing frame in the first embodiment of the present invention.

[0021] Figure 5 This is a cross-sectional schematic diagram of the swing frame in the first embodiment of the present invention.

[0022] Figure 6 This is a cross-sectional schematic diagram of the swing frame in the second embodiment of the present invention.

[0023] 1-Cam, 1.1-Annular groove; 2-Swing frame, 2.1-Swing plate, 2.2-Spring arm, 2.3-Swing arm, 2.4-Mounting part, 2.5-Threaded hole, 2.6-Slot, 2.7-Fixing plate; 3-Swing axis; 4-Front end cover, 4.1-Front end cover body, 4.2-Front seat body, 4.3-Through hole, 4.4-Snap fastener; 5- Rear end cover, 5.1- Rear cover body, 5.2- Rear seat body, 5.3- Through hole, 5.4- Buckle; 6-Outer shell; 7-Permanent magnet; 8-Rotor. Detailed Implementation

[0024] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0025] In the embodiments, such as Figure 1-5 As shown, a high-speed reciprocating drive module includes: a drive assembly consisting of a motor and a slotted cam 1 with multiple strokes, the slotted cam 1 being mounted on the output shaft end of the motor, and the circumferential surface of the slotted cam 1 having multiple strokes and parallel annular grooves 1.1 with the same normal cross section; and a swing frame 2 consisting of a swing plate 2.1, a spring arm 2.2, and a swing arm 2.3, the swing plate 2.1 being arranged parallel to the axis of the slotted cam 1, and the spring arm 2.2 being connected and supported between the swing plate 2.1 and both ends of the drive assembly. One end of the rocker arm 2.3 is rigidly connected to the rocker plate 2.1, and the other end is slidably engaged with the annular groove 1.1 via the rocker shaft 3. There are two sets of rocker plates 2.1, spring arms 2.2, rocker arms 2.3, and rocker shafts 3. The slotted cam 1 has two strokes, and the included angle between the two rocker shafts 3 is 90°. The rocker shaft 3 corresponding to the inner rocker plate 2.1 is arranged on the vertical axis plane of the slotted cam 1, and the rocker shaft 3 corresponding to the outer rocker plate 2.1 is arranged on the horizontal axis plane of the slotted cam 1. In this embodiment, by setting a slotted cam 1 with two driving strokes, and cooperating with two rocker shafts 3 with a phase difference of 90°, the rocker plate 2.1 can complete two reciprocating motions when the motor rotates one revolution. Compared with a single-stroke cam, the output frequency is doubled at the same speed, breaking through the traditional transmission frequency limitation. Due to the phase difference design, the two rocker plates 2.1 always swing in opposite directions, and their inertial forces cancel each other out in the drive assembly, significantly reducing overall vibration and noise, and improving handheld comfort. The spring arm 2.2 replaces the traditional bearing / connecting rod, directly connecting the rocker plate 2.1 to both ends of the drive assembly, reducing the number of parts and improving reliability. Figure 5 As shown, the inner swing shaft 3 is arranged vertically and the outer swing shaft 3 is arranged horizontally to avoid motion interference and reduce the lateral size of the module. The drive module of this embodiment is suitable for small household appliances such as electric toothbrushes, shavers, hair clippers, and facial cleansing devices.

[0026] In the embodiments, such as Figure 3 As shown, the axis of the rocker shaft 3 intersects perpendicularly with the axis of the cam 1. This perpendicular intersection ensures that the force exerted by the annular groove 1.1 on the rocker shaft 3 is always perpendicular to the plane of motion, reducing lateral friction and extending the lifespan of the mechanism. Simultaneously, it eliminates torque fluctuations caused by axis misalignment, reducing overall machine vibration and noise.

[0027] In the embodiments, such as Figure 3 As shown, the contour curve of the annular groove 1.1, when unfolded on the circumferential surface of the slotted cam 1, is a periodic function curve, including one or more of an elliptic curve, a sine curve, a modified sine curve, or a higher-order polynomial. The contour curve contains two periodic segments of identical shape connected end-to-end along the circumferential direction of the slotted cam 1, each corresponding to a drive stroke. During the rotation of the slotted cam 1, the instantaneous velocity components of any two points 90° apart on the contour curve are always the same in magnitude and opposite in direction along the axial direction of the slotted cam 1. The contour curve of the annular groove 1.1 uses a smooth function to avoid abrupt acceleration changes and reduce impact noise. The axial velocity components of points 90° apart on the contour curve are always opposite, ensuring that the two rocker plates 2.1 move in strictly opposite phases. This embodiment actually uses a simpler elliptical trajectory for the annular groove 1.1. To make the transmission smoother, an optimized trajectory, such as a modified sine curve, can be used to smooth the acceleration curve, reduce transmission impact, and further extend product life.

[0028] In the embodiments, such as Figure 1 , Figure 3 , Figure 4 As shown, the two spring arms 2.2 at the same end are connected to the mounting part 2.4, which is then connected to the drive assembly. The spring arms 2.2 at the same end are integrated into the mounting part 2.4, forming a stable support structure, improving resistance to deformation, and ensuring geometric accuracy under high-frequency motion; at the same time, it facilitates the modular and rapid assembly of the drive assembly and the swing frame 2, improving production efficiency.

[0029] In the embodiments, such as Figure 3 , 4 As shown, the rocker plate 2.1, spring arm 2.2, rocker arm 2.3, and mounting part 2.4 are integrally injection molded parts. Integral injection molding eliminates stress concentration points caused by traditional riveting / screwing, extends fatigue life, reduces the number of parts, saves assembly steps, and lowers manufacturing costs.

[0030] In the embodiments, such as Figure 3 , Figure 4As shown, a metal fixing plate 2.7 is embedded in the lower surface of the rocker plate 2.1. The metal fixing plate 2.7 can be embedded in the rocker frame 2 as an injection-molded insert to form a whole, thereby improving the strength and rigidity of the rocker plate 2.1, reducing deformation during instantaneous impact, suppressing motion trajectory deviation caused by plastic creep, and reducing displacement error of high-frequency reciprocating motion.

[0031] In the embodiments, such as Figure 3 As shown, the motor consists of a front cover 4, a rear cover 5, a housing 6, a permanent magnet 7, and a rotor 8. A cam 1 is mounted on the output shaft end of the rotor 8. The front cover 4 is divided into a front cover body 4.1 and a front seat body 4.2, and the rear cover 5 is divided into a rear cover body 5.1 and a rear seat body 5.2. The front cover body 4.1 and the rear cover body 5.1 are respectively inserted into the front and rear ends of the housing 6. The front seat body 4.2 and the rear seat body 5.2 extend outwards along the housing 6, forming two mounting parts 2.4. The front seat body 4.2 and the seat body 5.2 extend from the end cover to form the mounting parts, eliminating the need for an independent support structure. This not only compresses the axial space but also improves the overall installation stability of the drive assembly and the swing frame 2.

[0032] In the embodiments, such as Figure 3 , Figure 4 As shown, the bottom of the mounting part 2.4 is provided with a threaded hole 2.5, and the front seat 4.2 and rear seat 5.2 are respectively provided with through holes 4.3 and 5.3. The threaded hole 2.5 and the through holes 4.3 and 5.3 are connected and fixed by screws. The front and rear sides of the mounting part 2.4 are provided with slots 2.6, and the front and rear sides of the front seat 4.2 and rear seat 5.2 are respectively provided with buckles 4.4 and 5.4. The buckles 4.4 and 5.4 are engaged in the slots 2.6 for auxiliary fixing. The screw connection provides the main fixing force, and the engagement of the buckles 4.4 and 5.4 with the slots 2.6 plays an auxiliary role, helping to absorb vibration and impact and prevent the screws from loosening. At the same time, the engagement can play a positioning role during assembly, eliminating or simplifying tooling fixtures.

[0033] In another embodiment, such as Figure 6 As shown, the slotted cam 1 has a stroke of 3, and the two rocker shafts 3 are arranged symmetrically on both sides of the vertical axis plane of the slotted cam 1 at an angle of 60°. In this structure, the motor and the slotted cam 1 output 3 reciprocating cycles per revolution, increasing the frequency to 3 times that of the traditional structure, making it suitable for ultra-high frequency vibration scenarios. The two rocker shafts 3 are symmetrical with respect to the vertical axis plane, and their inertial torques are balanced, suppressing torsional vibration.

[0034] 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 high speed shuttle drive module, characterized by: include: The drive assembly consists of a motor and a slotted cam (1) with multiple strokes. The slotted cam (1) is mounted on the output shaft end of the motor. The circumferential surface of the slotted cam (1) is provided with annular grooves (1.1) with multiple strokes, the same normal cross section and parallel. The swing frame (2) consists of a swing plate (2.1), a swing arm (2.3) and a pair of spring arms (2.2). The swing plate (2.1) is arranged parallel to the axis of the slot cam (1). The two spring arms (2.2) are respectively connected and supported between the two ends of the swing plate (2.1) and the two ends of the drive assembly. One end of the swing arm (2.3) is rigidly connected to the swing plate (2.1), and the other end is slidably engaged with the annular groove (1.1) through the swing shaft (3). The rocker shaft (3), the rocker plate (2.1), the rocker arm (2.3) and the pair of spring arms (2.2) each have two sets; the number of driving strokes of the slot cam (1) is N, and the transmission phase difference between the two rocker shafts (3) and the slot cam (1) is π / N, so that the two rocker plates (2.1) swing in opposite directions; The contour curve of the annular groove (1.1) is a periodic function curve on the circumferential surface of the groove cam (1), including one or more of elliptic curves, sine curves, modified sine curves or higher-order polynomials. The contour curve contains N periodic variation segments with the same shape and connected end to end along the circumferential direction of the slot cam (1), and each periodic variation segment corresponds to one drive stroke. During the rotation of the slot cam (1), the instantaneous velocities of any two points on the contour curve that are separated by π / N radians are always opposite in direction to the components of the axial velocity of the slot cam (1).

2. The high speed shuttle drive module of claim 1, wherein, The number of strokes of the slotted cam (1) is 2, and the included angle between the two rocker shafts (3) is 90°; The rocking shaft (3) corresponding to the inner rocking plate (2.1) is arranged on the vertical axis plane of the slot cam (1), and the rocking shaft (3) corresponding to the outer rocking plate (2.1) is arranged on the horizontal axis plane of the slot cam (1).

3. The high-speed reciprocating drive module according to claim 1, characterized in that, The number of strokes of the slotted cam (1) is 3, and the included angle of the two rocker shafts (3) is 60°, which are symmetrically arranged on both sides of the vertical axis plane of the slotted cam (1).

4. The high-speed reciprocating drive module according to claim 1, 2, or 3, characterized in that, The axes of the two rocker shafts (3) intersect perpendicularly with the axis of the slot cam (1).

5. The high-speed reciprocating drive module according to claim 1, 2, or 3, characterized in that, The two spring arms (2.2) at the same end are connected to the mounting part (2.4), which is mounted to the drive assembly.

6. The high-speed reciprocating drive module according to claim 5, characterized in that, The motor consists of a front cover (4), a rear cover (5), an outer shell (6), a permanent magnet (7), and a rotor (8). The slotted cam (1) is installed on the output shaft end of the rotor (8). The front cover (4) is divided into a front cover body (4.1) and a front seat body (4.2). The rear cover (5) is divided into a rear cover body (5.1) and a rear seat body (5.2). The front cover body (4.1) and the rear cover body (5.1) are respectively inserted into the front end and the rear end of the outer shell (6). The front seat body (4.2) and the rear seat body (5.2) extend outward along the outer shell (6) to form the mounting positions of the two mounting parts (2.4).

7. The high-speed reciprocating drive module according to claim 6, characterized in that, The bottom of the mounting part (2.4) is provided with a threaded hole (2.5), and the front seat (4.2) and the rear seat (5.2) are provided with corresponding through holes (4.3, 5.3). The threaded hole (2.5) and the through holes (4.3, 5.3) are connected and fixed by screws.

8. The high-speed reciprocating drive module according to claim 7, characterized in that, The mounting part (2.4) is provided with slots (2.6) on the front and rear sides, and the front seat (4.2) and the rear seat (5.2) are provided with buckles (4.4, 5.4) on the front and rear sides respectively. The buckles (4.4, 5.4) are engaged in the slots (2.6) for auxiliary fixation.

9. The high-speed reciprocating drive module according to claim 5, characterized in that, The rocker plate (2.1), the spring arm (2.2), the rocker arm (2.3) and the mounting part (2.4) are integral injection molded parts, and a metal fixing plate (2.7) is inlaid on the lower surface of the rocker plate (2.1).

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