Linear driving mechanism

Abstract

The present invention relates to the technical field of linear driving, and in particular to a linear driving mechanism. The linear driving mechanism comprises a driving assembly and a transmission assembly that are fixedly connected to each other; the driving assembly drives the transmission assembly to move; the transmission assembly comprises a second housing; the second housing comprises a hollow housing body, a ring gear formed at the end of the housing body close to the driving assembly, and a slide rail formed by recessing from the end of the housing body distant from the driving assembly toward the end close to the driving assembly; the ring gear is engaged with a gear assembly; a stator assembly drives a rotor assembly to rotate so as to drive a lead screw to rotate, such that the lead screw rotates to drive a push rod to achieve linear extension and retraction. Compared with the prior art, in the present invention, the slide rail, the ring gear and the housing are integrally formed into a second housing, and the second housing is injection-molded from high-strength plastic pellets, thereby facilitating mass production and ensuring greater dimensional stability.

Description

Linear drive mechanism Technical Field

[0001] This invention relates to the field of linear drive technology, and more particularly to a linear drive mechanism. Background Technology

[0002] With the rapid development of the artificial intelligence and robotics industries, the fingers of humanoid robots are a crucial part of their ability to perform actions and complete tasks. Due to stricter requirements regarding space and energy efficiency, linear actuators are facing increasingly stringent demands, leading to their development towards higher integration, smaller size, higher load-bearing capacity, and faster response. A linear drive mechanism is a type of linear actuator that uses a lead screw as the driving element and a push rod for linear output; that is, the push rod does not rotate but extends and retracts along the axial direction, while the lead screw rotates. Technical issues

[0003] In the linear drive mechanism of the related technology, a plastic slide rail is assembled between the housing and the push rod, and a plastic gear ring is assembled between the housing and the gear set. However, due to the long dimensional chain relationship caused by the assembly of multiple parts in the existing linear drive mechanism, it has an adverse effect on the parts processing, assembly efficiency and transmission performance.

[0004] Therefore, it is necessary to provide a new linear drive mechanism to solve the above-mentioned technical problems. Technical solutions

[0005] The purpose of this invention is to provide a linear drive mechanism that reduces the number of transmission component parts, thereby improving assembly efficiency and accuracy.

[0006] To achieve the above objectives, the present invention provides a linear drive mechanism, comprising a drive assembly and a transmission assembly fixedly connected to each other;

[0007] The drive assembly includes a first housing, a stator assembly disposed within the first housing, and a rotor assembly disposed within the stator assembly. The rotor assembly passes through one end of the first housing near the transmission assembly, and the stator assembly drives the rotor assembly to rotate.

[0008] The transmission assembly includes a second housing, a first cover plate fixed to the second housing at the end away from the drive assembly, a gear assembly installed inside the second housing near the drive assembly, a lead screw fixed inside the second housing and located on the side of the gear assembly away from the drive assembly, a push rod disposed inside the second housing and located on the side of the lead screw away from the drive assembly, and a connecting member located on the end of the gear assembly near the drive assembly and rotatably connected to the gear assembly; the end of the connecting member near the drive assembly is fixedly connected to the output end of the rotor assembly, the push rod passes through the first cover plate and is slidably connected to the first cover plate, and the lead screw and the push rod are linearly connected.

[0009] The second housing includes a hollow housing body, a gear ring recessed from one end of the housing body near the drive assembly to the end away from the drive assembly, and a slide rail recessed from the inner circumference of the housing body. The slide rail extends from one end of the housing body away from the drive assembly to the end near the drive assembly. The gear assembly is supported on the side of the gear ring near the drive assembly and meshes with the gear ring. The push rod is slidably connected to the slide rail.

[0010] Preferably, the second housing is integrally injection molded from plastic particles.

[0011] Preferably, the plastic particles have a yield strength greater than or equal to 475 MPa and a tensile strength greater than or equal to 330 MPa at an environment of 23~30℃.

[0012] Preferably, the plastic particles are PEEK substrate, and by weight, the plastic particles contain at least 40% carbon fiber.

[0013] Preferably, the end of the push rod away from the drive assembly is provided with a pin hole that extends radially through the push rod.

[0014] Preferably, the transmission assembly further includes a bearing coaxially arranged with the lead screw and welded to one end of the lead screw near the drive assembly, wherein the outer peripheral side of the bearing is fixed to the inner peripheral side of the second housing.

[0015] Preferably, the housing body further includes a plurality of screw holes fixed to the outer periphery of the bearing and distributed along the bearing axial direction, wherein a plurality of screws pass through the plurality of screw holes to fix the bearing in the second housing.

[0016] Preferably, the connector includes a connector body fixedly connected to the output end of the rotor assembly and a transmission portion extending from the connector body toward the lead screw, the transmission portion meshing with the gear assembly.

[0017] Preferably, the gear assembly includes a fixed bracket fixed to one end of the lead screw near the drive assembly, a plurality of fixed posts extending from the fixed bracket toward the drive assembly, and a plurality of gears respectively sleeved on the fixed posts and rotatably connected to the fixed posts. The plurality of gears mesh sequentially and with the gear ring, wherein one of the gears meshes with the transmission part.

[0018] Preferably, the gears comprise three gears with different outer diameters, and the three gears mesh sequentially from smallest to largest.

[0019] Preferably, the slide rail includes a sidewall recessed from one end of the housing body away from the drive assembly toward the end closer to the drive assembly, and a plurality of limiting walls extending from the sidewall along the radial direction of the push rod, the plurality of limiting walls being spaced apart from each other and tangent to the push rod.

[0020] Preferably, the rotor assembly includes a rotating shaft supported on the first housing and forming a rotatable connection, an iron core sleeved and fixed to the rotating shaft, and a permanent magnet sleeved and fixed to the iron core. The permanent magnet and the stator assembly are spaced apart from each other, and the rotating shaft passes through the first housing and is fixedly connected to the connector. Beneficial effects

[0021] Compared with existing technologies, this invention integrates the slide rail, gear ring, and housing into a second housing, which improves the assembly efficiency and precision of the linear drive mechanism. The second housing is made of high-strength plastic particles through injection molding, facilitating mass production and ensuring greater dimensional stability. The gear ring in the second housing cooperates with the gear assembly to achieve the speed reduction function of the transmission component. Simultaneously, the increased space in the gear assembly allows for the design of gears with larger reduction ratios and higher strength. The slide rail in the second housing cooperates with the push rod to achieve the reversing function of the transmission component, converting the rotational motion of the push rod into the required linear motion. The straight edge of the slide rail area can limit the four degrees of freedom of the push rod, working together with the lead screw to control the linear motion of the push rod. The second housing has screw holes on the outer periphery of the bearing, using screws to secure the bearing and achieve the lead screw positioning function of the transmission component. The lead screw and bearing are welded together, eliminating the traditional threaded connection method, resulting in a more stable and reliable connection. The push rod eliminates the sliding ring and threaded interface, replacing them with a pin hole interface. The pin hole direction is fixed, ensuring higher consistency with external interfaces. By reducing the number of parts through high integration, the transmission mechanism is simplified, assembly efficiency and accuracy are improved, production costs are reduced, and mass production is facilitated. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0023] Figure 1 is a three-dimensional structural schematic diagram of the linear drive mechanism provided in an embodiment of the present invention;

[0024] Figure 2 is a three-dimensional exploded view of the linear drive mechanism provided in an embodiment of the present invention;

[0025] Figure 3 is a cross-sectional view along line AA in Figure 1;

[0026] Figure 4 is a schematic diagram of the slide rail side of the second housing of the linear drive mechanism provided in an embodiment of the present invention.

[0027] Figure 5 is a schematic diagram of the gear ring side of the second housing of the linear drive mechanism provided in an embodiment of the present invention.

[0028] In the diagram, 100 is the linear drive mechanism, 1 is the drive assembly, 11 is the first housing, 111 is the first housing body, 112 is the second cover plate, 12 is the stator assembly, 13 is the rotor assembly, 131 is the rotating shaft, 132 is the iron core, 133 is the permanent magnet, 2 is the transmission assembly, 21 is the second housing, 211 is the housing body, 212 is the slide rail, 2121 is the side wall, 2122 is the limiting wall, 213 is the gear ring, 214 is the screw hole post, 22 is the first cover plate, 23 is the push rod, 231 is the pin hole, 24 is the lead screw, 25 is the gear assembly, 251 is the fixed bracket, 252 is the fixed column, 253 is the gear, 26 is the connector, 261 is the connector body, 262 is the transmission part, 27 is the bearing, 28 is the screw, 3 is the sensor assembly, 31 is the control board, 32 is the Hall sensor, and 33 is the sensor magnet. Embodiments of the present invention

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Referring to Figures 1 to 5, this embodiment of the invention provides a linear drive mechanism 100, which includes a drive assembly 1 and a transmission assembly 2 that are fixedly connected to each other.

[0031] The drive assembly 1 includes a first housing 11, a stator assembly 12 disposed within the first housing 11, and a rotor assembly 13 disposed within the stator assembly 12. The rotor assembly 13 passes through one end of the first housing 11 near the transmission assembly 2, and the stator assembly 12 drives the rotor assembly 13 to rotate.

[0032] The transmission assembly 2 includes a second housing 21, a first cover plate 22 fixed to the end of the second housing 21 away from the drive assembly 1, a gear assembly 25 installed inside the second housing 21 near the end of the drive assembly 1, a lead screw 24 fixed inside the second housing 21 and located on the side of the gear assembly 25 away from the drive assembly 1, a push rod 23 disposed inside the second housing 21 and located on the side of the lead screw 24 away from the drive assembly 1, and a connector 26 located on the end of the gear assembly 25 near the drive assembly 1 and rotatably connected to the gear assembly 25; the end of the connector 26 near the drive assembly 1 is fixedly connected to the output end of the rotor assembly 13, the push rod 23 passes through the first cover plate 22 and is slidably connected to the first cover plate 22, and the lead screw 24 and the push rod 23 are linearly connected.

[0033] The second housing 21 includes a hollow housing body 211, a gear ring 213 recessed from one end of the housing body 211 near the drive assembly 1 to the end away from the drive assembly 1, and a slide rail 212 recessed from the inner shaft side of the housing body 211. The slide rail 212 extends from one end of the housing body 211 away from the drive assembly 1 to the end near the drive assembly 1. The gear assembly 25 is supported on the side of the gear ring 213 near the drive assembly 1 and meshes with the gear ring 213. The push rod 23 is slidably connected to the slide rail 212.

[0034] Specifically, the gear ring 213 in the second housing 21 cooperates with the gear assembly 25 to realize the deceleration function of the transmission assembly 2. At the same time, since the space of the gear assembly 25 is further freed up, it is easier to design a gear assembly 25 with a larger reduction ratio and higher strength. The slide rail 212 in the second housing 21 cooperates with the push rod 23 to realize the reversing function of the transmission assembly 2 (that is, to convert the rotational motion of the push rod 23 into the required linear motion).

[0035] The stator assembly 12 drives the rotor assembly 13 to rotate, thereby causing the lead screw 24 to rotate, which in turn drives the push rod 23 to achieve linear telescopic motion.

[0036] In this embodiment, the second housing 21 is injection molded from plastic particles using a mold. Specifically, the plastic particles are high-strength plastic particles. Since the second housing 21 is injection molded from high-strength plastic particles, it facilitates mass production and ensures more stable dimensions. For example, the plastic particles have a yield strength greater than or equal to 475 MPa and a tensile strength greater than or equal to 330 MPa at 23-30°C. The plastic particles are PEEK (polyetheretherketone) substrate, and by mass percentage, they contain at least 40% carbon fiber.

[0037] In this embodiment, the end of the push rod 23 furthest from the drive assembly 1 has a pin hole 231 formed radially through the push rod 23. Since the push rod 23 eliminates the sliding ring and threaded interface, replacing them with a pin hole interface, and the direction of the pin hole 231 is fixed, the consistency with external interfaces is higher. By reducing the number of parts through high integration, the structure of the transmission assembly 2 is simplified, the assembly efficiency and accuracy of the linear drive mechanism 100 are improved, production costs are reduced, and mass production is facilitated.

[0038] In this embodiment, the transmission assembly 2 further includes a bearing 27 coaxially arranged with the lead screw 24 and welded to one end of the lead screw 24 near the drive assembly 1. The outer periphery of the bearing 27 is fixed to the inner shaft side of the second housing. The lead screw 24 and the bearing 27 are connected by welding, eliminating the threaded connection method in the prior art, and the connection is more stable and reliable.

[0039] In this embodiment, the housing body 211 further includes a plurality of screw hole posts 214 fixed to the outer peripheral side of the bearing 27 and distributed along the axial direction of the bearing 27. A plurality of screws 28 pass through the plurality of screw hole posts 214 to fix the bearing 27 inside the second housing 21. Specifically, the screws 28 are self-tapping screws, and the screws 28 are used to lock the bearing 27 to achieve the positioning function of the lead screw 24.

[0040] In this embodiment, the connector 26 includes a connector body 261 fixedly connected to the output end of the rotor assembly 13 and a transmission part 262 formed by the connector body 261 extending toward the lead screw 24, the transmission part 262 meshing with the gear assembly 25.

[0041] In this embodiment, the gear assembly 25 includes a fixed bracket 251 fixed to one end of the lead screw 24 near the drive assembly 1, a plurality of fixed posts 252 extending from the fixed bracket 251 toward the drive assembly 1, and a plurality of gears 253 respectively sleeved on the fixed posts 252 and rotatably connected to the fixed posts 252. The plurality of gears 253 mesh sequentially and mesh with the gear ring 213, and one of the gears 253 meshes with the transmission part 262.

[0042] In this embodiment, the gears 253 include three gears spaced apart from each other with different outer diameters. The three gears 253 mesh sequentially from smallest to largest. By controlling the outer diameter of the three gears 253, the rotation speed of the multiple gears 253 can be controlled, thereby controlling the linear transmission speed of the lead screw 24 and the push rod 23.

[0043] In this embodiment, the slide rail 212 includes a sidewall 2121 formed by recessing from one end of the housing body 211 away from the drive assembly 1 towards the other end, and a plurality of limiting walls 2122 formed by extending the sidewall 2121 along the radial direction of the push rod 23. The plurality of limiting walls 2122 are spaced apart from each other and tangent to the push rod 23. The multiple limiting walls 2122 limit the degrees of freedom of the push rod 23, and together with the lead screw 24, control the linear movement of the push rod 23.

[0044] In this embodiment, the rotor assembly 13 includes a rotating shaft 131 supported on the first housing 11 and rotatably connected thereto, an iron core 132 sleeved and fixed to the rotating shaft 131, and a permanent magnet 133 sleeved and fixed to the iron core 132. The permanent magnet 133 and the stator assembly 12 are spaced apart from each other. The rotating shaft 131 passes through the first housing 11 and is fixedly connected to the connector 26.

[0045] In this embodiment, the first housing 11 includes a first housing body 111 and a second cover plate 112 covering the first housing body 111 near the end of the transmission assembly 2. The end of the second cover plate 112 away from the first housing body 111 is fixedly connected to the second housing 21. The rotating shaft 131 passes through the first housing body 111 and is rotatably connected to the connector 26.

[0046] In this embodiment, the linear drive mechanism 100 further includes a sensor assembly 3, which is used to detect the movement data of the push rod 23. The sensor assembly 3 includes a control board 31 embedded and fixed in the first housing 11 and the second housing 21, a Hall sensor 32 fixed to one end of the control board 31 near the push rod 23, and a sensor magnet 33 fixed to the second housing 21. The sensor magnet 33 and the Hall sensor 32 are arranged at intervals.

[0047] Compared with existing technologies, this invention integrates the slide rail, gear ring, and housing into a second housing, which improves the assembly efficiency and precision of the linear drive mechanism. The second housing is made of high-strength plastic particles through injection molding, facilitating mass production and ensuring greater dimensional stability. The gear ring in the second housing cooperates with the gear assembly to achieve the speed reduction function of the transmission component. Simultaneously, the increased space in the gear assembly allows for the design of gears with larger reduction ratios and higher strength. The slide rail in the second housing cooperates with the push rod to achieve the reversing function of the transmission component, converting the rotational motion of the push rod into the required linear motion. The straight edge of the slide rail area can limit the four degrees of freedom of the push rod, working together with the lead screw to control the linear motion of the push rod. The second housing has screw holes on the outer periphery of the bearing, using screws to secure the bearing and achieve the lead screw positioning function of the transmission component. The lead screw and bearing are welded together, eliminating the traditional threaded connection method, resulting in a more stable and reliable connection. The push rod eliminates the sliding ring and threaded interface, replacing them with a pin hole interface. The pin hole direction is fixed, ensuring higher consistency with external interfaces. By reducing the number of parts through high integration, the transmission mechanism is simplified, assembly efficiency and accuracy are improved, production costs are reduced, and mass production is facilitated.

[0048] The above description is merely an embodiment of the present invention. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of the present invention, but these improvements all fall within the protection scope of the present invention.

Claims

1. A linear drive mechanism, comprising a drive assembly and a transmission assembly fixedly connected to each other; The drive assembly includes a first housing, a stator assembly disposed within the first housing, and a rotor assembly disposed within the stator assembly. The rotor assembly extends through the first housing at one end near the transmission assembly, and the stator assembly drives the rotor assembly to rotate. The characteristic of this assembly is that... The transmission assembly includes a second housing, a first cover plate fixed to the second housing at the end away from the drive assembly, a gear assembly installed inside the second housing near the end of the drive assembly, a lead screw fixed inside the second housing and located on the side of the gear assembly away from the drive assembly, a push rod disposed inside the second housing and located on the side of the lead screw away from the drive assembly, and a connecting member located on the end of the gear assembly near the drive assembly and rotatably connected to the gear assembly; The end of the connector near the drive assembly is fixedly connected to the output end of the rotor assembly; the push rod passes through the first cover plate and forms a sliding connection with the first cover plate; the lead screw forms a linear transmission connection with the push rod. The second housing includes a hollow housing body, a gear ring recessed from one end of the housing body near the drive assembly to the end away from the drive assembly, and a slide rail recessed from the inner circumference of the housing body, the slide rail extending from one end of the housing body away from the drive assembly to the end near the drive assembly; the gear assembly is supported on the side of the gear ring near the drive assembly and meshes with the gear ring, and the push rod is slidably connected to the slide rail.

2. The linear drive mechanism of claim 1, wherein The second housing is integrally injection molded from plastic particles.

3. The linear drive mechanism of claim 2, wherein, The plastic particles have a yield strength greater than or equal to 475 MPa and a tensile strength greater than or equal to 330 MPa at an environment of 23~30℃.

4. The linear drive mechanism of claim 2, wherein, The plastic particles are PEEK-based and contain at least 40% carbon fiber by weight.

5. The linear drive mechanism of claim 1, wherein, The end of the push rod away from the drive assembly has a pin hole that extends radially through the push rod.

6. The linear drive mechanism of claim 1, wherein, The transmission assembly further includes a bearing coaxially arranged with the lead screw and welded to one end of the lead screw near the drive assembly, wherein the outer peripheral side of the bearing is fixed to the inner peripheral side of the second housing.

7. The linear drive mechanism of claim 6, wherein The housing body also includes a plurality of screw holes fixed to the outer periphery of the bearing and distributed along the bearing axis, wherein a plurality of screws pass through the plurality of screw holes to fix the bearing inside the second housing.

8. The linear drive mechanism of claim 1, wherein, The connector includes a connector body fixedly connected to the output end of the rotor assembly and a transmission part extending from the connector body toward the lead screw, the transmission part meshing with the gear assembly.

9. The linear drive mechanism of claim 8, wherein, The gear assembly includes a fixed bracket fixed to one end of the lead screw near the drive assembly, a plurality of fixed posts extending from the fixed bracket toward the drive assembly, and a plurality of gears respectively sleeved on the fixed posts and rotatably connected to the fixed posts. The plurality of gears mesh sequentially and with the gear ring, and one of the gears meshes with the transmission part.

10. The linear drive mechanism of claim 9, wherein, The gears consist of three gears with different outer diameters, and the three gears mesh in sequence from smallest to largest.

11. The linear drive mechanism of claim 1, wherein, The slide rail includes a sidewall recessed from one end of the housing body away from the drive assembly toward the end closer to the drive assembly, and a plurality of limiting walls extending from the sidewall along the radial direction of the push rod, the plurality of limiting walls being spaced apart from each other and tangent to the push rod.

12. The linear drive mechanism of claim 1, wherein, The rotor assembly includes a rotating shaft supported on the first housing and forming a rotatable connection, an iron core sleeved and fixed to the rotating shaft, and a permanent magnet sleeved and fixed to the iron core. The permanent magnet and the stator assembly are spaced apart from each other, and the rotating shaft passes through the first housing and is fixedly connected to the connector.

Images