Linear driving mechanism

Abstract

The invention relates to the technical field of linear driving, in particular to a linear driving mechanism which comprises a driving assembly and a transmission assembly which are fixedly connected with each other, the driving assembly drives the transmission assembly to move, and the transmission assembly comprises a second machine shell. The second machine shell comprises a hollow machine shell body, a gear ring formed by the end, close to the driving assembly, of the machine shell body, and a sliding rail formed by sinking the end, away from the driving assembly, of the machine shell body towards the end, close to the driving assembly, of the machine shell body. The gear ring is in meshed connection with the gear assembly. The stator assembly drives the rotor assembly to rotate to drive the lead screw to rotate, so that the lead screw rotates to drive the push rod to achieve linear telescopic motion. Compared with the prior art, the sliding rail, the gear ring and the machine shell are integrated to form the second machine shell, the second machine shell is formed by high-strength plastic particles in an injection molding mode through a mold, batch production is facilitated, and the size is more stable.

Description

Technical Field

[0001] The present invention relates to the field of linear drive technology, and in particular to a linear drive mechanism. Background Art

[0002] With the rapid development of artificial intelligence and robotics, the fingers of humanoid robots are an important part of their ability to perform actions and complete tasks. As space, energy efficiency and other requirements put forward stricter requirements on linear actuators, linear actuators are developing towards high integration, smaller size, higher load capacity and faster response. The linear drive mechanism is a type of linear actuator that uses a lead screw as the active part and a push rod as a linear output, that is, the push rod does not rotate but moves in a telescopic manner along the axis, and the lead screw rotates.

[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 assembly of multiple parts in the existing linear drive mechanism, a long dimensional chain relationship is caused, which has an adverse effect on part processing, assembly efficiency, and transmission performance.

[0004] Therefore, it is necessary to provide a new linear drive mechanism to solve the above technical problems. Summary of the invention

[0005] The object of the present invention is to provide a linear drive mechanism which reduces the number of transmission component parts and thus improves assembly efficiency and precision.

[0006] In order to achieve the above object, the present invention provides a linear drive mechanism, including a drive assembly and a transmission assembly fixedly connected to each other; The driving assembly includes a first housing, a stator assembly disposed in the first housing, and a rotor assembly disposed in the stator assembly, the rotor assembly passes through one end of the first housing close to the transmission assembly, and the stator assembly drives the rotor assembly to rotate; The transmission assembly includes a second housing, a first cover plate fixed to an end of the second housing away from the driving assembly, a gear assembly installed in the second housing near an end of the driving assembly, a lead screw fixed in the second housing and located on a side of the gear assembly away from the driving assembly, a push rod provided in the second housing and located on a side of the lead screw away from the driving assembly, and a connecting member located at an end of the gear assembly near the driving assembly and forming a rotational connection with the gear assembly; an end of the connecting member near the driving assembly is fixedly connected to an output end of the rotor assembly, the push rod penetrates the first cover plate and forms a sliding connection with the first cover plate, and the lead screw and the push rod form a linear transmission connection; The second casing includes a hollow casing body, a gear ring formed by an end of the casing body close to the drive assembly being recessed toward an end away from the drive assembly, and a slide rail formed by a recess on the inner circumference of the casing body, wherein the slide rail extends from an end of the casing body away from the drive assembly to an end close to the drive assembly; the gear assembly is supported on a side of the gear ring close to the drive assembly and meshes with the gear ring, and the push rod forms a sliding connection with the slide rail.

[0007] Preferably, the second housing is integrally injection-molded using plastic particles.

[0008] 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 under a temperature of 23-30°C.

[0009] Preferably, the plastic particles are PEEK-based and comprise at least 40% carbon fibers by mass.

[0010] Preferably, one end of the push rod away from the driving assembly is provided with a pin hole formed penetrating along the radial direction of the push rod.

[0011] Preferably, the transmission assembly further comprises a bearing which is coaxially arranged with the screw rod and welded and fixed to one end of the screw rod close to the driving assembly, and the outer peripheral side of the bearing is fixed to the inner peripheral side of the second housing.

[0012] Preferably, the housing body further comprises a plurality of screw hole columns fixed to the outer peripheral side of the bearing and distributed along the axial direction of the bearing, and a plurality of screws respectively pass through the plurality of screw hole columns to fix the bearing in the second housing.

[0013] Preferably, the connecting member comprises a connecting member body fixedly connected to the output end of the rotor assembly and a transmission portion formed by extending the connecting member body toward the direction close to the screw rod, and the transmission portion is meshed with the gear assembly.

[0014] Preferably, the gear assembly includes a fixed bracket fixed to one end of the screw rod close to the driving assembly, a plurality of fixed columns extended from the fixed bracket toward the driving assembly, and a plurality of gears respectively sleeved on the fixed columns and rotatably connected with the fixed columns, the plurality of gears meshing in sequence and with the gear ring, and one of the gears meshes with the transmission part.

[0015] Preferably, the gears include three gears with different outer diameters, and the three gears are meshed in sequence from small to large.

[0016] Preferably, the slide rail includes a side wall formed by an end of the casing body that is recessed toward an end close to the driving assembly, and a plurality of limiting walls formed by the side wall extending along the radial direction of the push rod, wherein the plurality of limiting walls are spaced apart from each other and tangent to the push rod.

[0017] Preferably, the rotor assembly includes a rotating shaft supported by the first housing and rotatably connected to the first housing, 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 connecting member.

[0018] Compared with the prior art, the present invention integrates the slide rail, the gear ring and the housing to form the second housing, which is conducive to improving the assembly efficiency and precision of the linear drive mechanism. The second housing is formed by injection molding of high-strength plastic particles, which is conducive to mass production and has more stable size. The gear ring part in the second housing cooperates with the gear assembly to realize the deceleration function of the transmission assembly. At the same time, since the space of the gear assembly is further released, it is convenient to design a gear assembly with a larger reduction ratio and higher strength. The slide rail part in the second housing cooperates with the push rod to realize the reversing function of the transmission assembly, that is, the rotational motion of the push rod is converted into the required linear motion. The straight edge of the slide rail area can limit the four degrees of freedom of the push rod, and together with the screw rod, the linear motion of the push rod can be controlled. The second housing is designed with a screw hole column on the outer peripheral side of the bearing, and the screw locking bearing is used to realize the screw rod positioning function of the transmission assembly. The screw rod and the bearing are connected by welding, eliminating the traditional threaded connection method, and the connection is more stable and reliable; the push rod eliminates the sliding ring and the threaded interface, and replaces them with a pin hole interface, the direction of the pin hole is fixed, and the consistency with the external interface is higher. Reducing the number of parts through high integration not only simplifies the transmission mechanism, but also improves assembly efficiency and precision, reduces production costs, and facilitates mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. 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 work, among which: Figure 1 A schematic diagram of the three-dimensional structure of a linear drive mechanism provided in an embodiment of the present invention; Figure 2 A schematic diagram of a three-dimensional structure decomposition of a linear drive mechanism provided in an embodiment of the present invention; Figure 3 For along Figure 1 The cross-section diagram of the AA line; Figure 4A schematic structural diagram of the slide rail side of the second housing of the linear drive mechanism provided by an embodiment of the present invention; Figure 5 A schematic structural diagram of the gear ring side of the second housing of the linear drive mechanism provided by an embodiment of the present invention.

[0020] In the figure, 100, linear drive mechanism, 1, drive component, 11, first housing, 111, first housing body, 112, second cover plate, 12, stator component, 13, rotor component, 131, rotating shaft, 132, iron core, 133, permanent magnet, 2, transmission component, 21, second housing, 211, housing body, 212, slide rail, 2121, side wall, 2122, limiting wall, 213, gear ring, 214, screw hole column, 22, first cover plate, 23, push rod, 231, pin hole, 24, screw rod, 25, gear assembly, 251, fixed bracket, 252, fixed column, 253, gear, 26, connecting piece, 261, connecting piece body, 262, transmission part, 27, bearing, 28, screw, 3, sensor component, 31, control board, 32, Hall sensor, 33, sensor magnet. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Combination Figures 1 to 5 As shown, an embodiment of the present invention provides a linear drive mechanism 100, and the linear drive mechanism 100 includes: a drive assembly 1 and a transmission assembly 2 fixedly connected to each other.

[0023] The driving assembly 1 includes a first housing 11, a stator assembly 12 disposed in the first housing 11, and a rotor assembly 13 disposed in the stator assembly 12. The rotor assembly 13 penetrates one end of the first housing 11 close to the transmission assembly 2, and the stator assembly 12 drives the rotor assembly 13 to rotate. The transmission assembly 2 includes a second housing 21, a first cover plate 22 fixed to an end of the second housing 21 away from the drive assembly 1, a gear assembly 25 installed in the second housing 21 near the end of the drive assembly 1, a screw rod 24 fixed in the second housing 21 and located on the side of the gear assembly 25 away from the drive assembly 1, a push rod 23 arranged in the second housing 21 and located on the side of the screw rod 24 away from the drive assembly 1, and a connecting member 26 located at an end of the gear assembly 25 close to the drive assembly 1 and forming a rotational connection with the gear assembly 25; the end of the connecting member 26 close to 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 forms a sliding connection with the first cover plate 22, and the screw rod 24 forms a linear transmission connection with the push rod 23.

[0024] The second housing 21 includes a hollow housing body 211, a gear ring 213 formed by an end of the housing body 211 close to the drive assembly 1 being recessed toward an end away from the drive assembly 1, and a slide rail 212 formed by a recess on the inner shaft side of the housing body 211, wherein the slide rail 212 extends from an end of the housing body 211 away from the drive assembly 1 to an end close to the drive assembly 1; the gear assembly 25 is supported on a side of the gear ring 213 close to the drive assembly 1 and meshes with the gear ring 213, and the push rod 23 forms a sliding connection with the slide rail 212.

[0025] Specifically, the deceleration function of the transmission assembly 2 is realized by the cooperation between the ring gear 213 in the second housing 21 and the gear assembly 25. At the same time, since the space of the gear assembly 25 is further released, it is easier to design a gear assembly 25 with a larger deceleration 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, converting the rotational motion of the push rod 23 into the required linear motion).

[0026] The stator assembly 12 drives the rotor assembly 13 to rotate to drive the screw rod 24 to rotate, so that the screw rod 24 rotates to drive the push rod 23 to achieve linear telescopic motion.

[0027] In this embodiment, the second housing 21 is formed by injection molding of plastic particles, and the specific plastic particles are high-strength plastic particles. Since the second housing 21 is formed by injection molding of high-strength plastic particles, it is conducive to mass production and has more stable dimensions. Exemplarily, the yield strength of the plastic particles is greater than or equal to 475MPa and the tensile strength is greater than or equal to 330MPa under an environment of 23-30°C. The plastic particles are PEEK (polyetheretherketone) substrates, and the plastic particles include at least 40% carbon fiber by mass percentage.

[0028] In this embodiment, the end of the push rod 23 away from the drive assembly 1 is provided with a pin hole 231 formed along the radial direction of the push rod 23. Since the push rod 23 cancels the sliding ring and the threaded interface and replaces it with a pin hole interface, and the direction of the pin hole 231 is fixed, the consistency with the external interface 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, the production cost is reduced, and it is conducive to mass production.

[0029] In this embodiment, the transmission assembly 2 further includes a bearing 27 coaxially arranged with the screw rod 24 and welded to the end of the screw rod 24 close to the driving assembly 1, and the outer peripheral side of the bearing 27 is fixed to the inner shaft side of the second housing. The screw rod 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.

[0030] In this embodiment, the housing body 211 further includes a plurality of screw holes 214 fixed to the outer peripheral side of the bearing 27 and distributed along the axial direction of the bearing 27, and a plurality of screws 28 respectively pass through the plurality of screw holes 214 to fix the bearing 27 in 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 screw rod 24.

[0031] 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 portion 262 formed by extending the connector body 261 toward the screw rod 24 , and the transmission portion 262 meshes with the gear assembly 25 .

[0032] In this embodiment, the gear assembly 25 includes a fixed bracket 251 fixed to one end of the screw rod 24 close to the driving assembly 1, a plurality of fixed columns 252 extending from the fixed bracket 251 toward the driving assembly 1, and a plurality of gears 253 respectively sleeved on the fixed columns 252 and rotatingly connected to the fixed columns 252. The plurality of gears 253 are meshed in sequence and meshed with the ring gear 213, and one of the gears 253 is meshed with the transmission part 262.

[0033] In this embodiment, the gear 253 includes three gears 253 that are spaced apart from each other and have different outer diameters. The three gears 253 are meshed in sequence from small to large. By controlling the outer diameters of the three gears 253, the rotation speed of the multiple gears 253 can be controlled to control the linear transmission speed of the screw rod 24 and the push rod 23.

[0034] In this embodiment, the slide rail 212 includes a side wall 2121 formed by an end of the housing body 211 that is recessed toward an end close to the driving assembly 1, and a plurality of limiting walls 2122 formed by the side wall 2121 extending 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 plurality of limiting walls 2122 limit the freedom of the push rod 23, and together with the screw rod 24, the push rod 23 is controlled to move linearly.

[0035] In this embodiment, the rotor assembly 13 includes a rotating shaft 131 supported on the first housing 11 and forming a rotational connection, an iron core 132 sleeved and fixed on the rotating shaft 131, and a permanent magnet 133 sleeved and fixed on the iron core 132, the permanent magnet 133 and the stator assembly 12 are spaced apart from each other, and the rotating shaft 131 passes through the first housing 11 and is fixedly connected to the connecting member 26.

[0036] In this embodiment, the first housing 11 includes a first housing body 111 and a second cover plate 112 covering one end of the first housing body 111 close to the transmission assembly 2, the second cover plate 112 is fixedly connected to the second housing 21 at one end away from the first housing body 111, and the rotating shaft 131 passes through the first housing body 111 and is rotatably connected to the connecting member 26.

[0037] In this embodiment, the linear drive mechanism 100 also includes a sensor component 3, which is used to detect the movement data of the push rod 23. The sensor component 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 the control board 31 near one end of 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 from each other.

[0038] Compared with the prior art, the present invention integrates the slide rail, the gear ring and the housing to form the second housing, which is conducive to improving the assembly efficiency and precision of the linear drive mechanism. The second housing is formed by injection molding of high-strength plastic particles, which is conducive to mass production and has more stable size. The gear ring part in the second housing cooperates with the gear assembly to realize the deceleration function of the transmission assembly. At the same time, since the space of the gear assembly is further released, it is convenient to design a gear assembly with a larger reduction ratio and higher strength. The slide rail part in the second housing cooperates with the push rod to realize the reversing function of the transmission assembly, that is, the rotational motion of the push rod is converted into the required linear motion. The straight edge of the slide rail area can limit the four degrees of freedom of the push rod, and together with the screw rod, the linear motion of the push rod can be controlled. The second housing is designed with a screw hole column on the outer peripheral side of the bearing, and the screw locking bearing is used to realize the screw rod positioning function of the transmission assembly. The screw rod and the bearing are connected by welding, eliminating the traditional threaded connection method, and the connection is more stable and reliable; the push rod eliminates the sliding ring and the threaded interface, and replaces them with a pin hole interface, the direction of the pin hole is fixed, and the consistency with the external interface is higher. Reducing the number of parts through high integration not only simplifies the transmission mechanism, but also improves assembly efficiency and precision, reduces production costs, and facilitates mass production.

[0039] The above description is only an implementation mode of the present invention. It should be pointed out that, for ordinary technicians in this field, improvements can be made without departing from the creative concept of the present invention, but these all belong to 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 driving assembly includes a first housing, a stator assembly disposed in the first housing, and a rotor assembly disposed in the stator assembly, wherein the rotor assembly penetrates one end of the first housing close to the transmission assembly, and the stator assembly drives the rotor assembly to rotate; characterized in that: The transmission assembly includes a second housing, a first cover plate fixed to an end of the second housing away from the driving assembly, a gear assembly installed in the second housing near an end of the driving assembly, a screw rod fixed in the second housing and located at a side of the gear assembly away from the driving assembly, a push rod arranged in the second housing and located at a side of the screw rod away from the driving assembly, and a connecting member located at an end of the gear assembly near the driving assembly and forming a rotational connection with the gear assembly; One end of the connecting member close to the driving assembly is fixedly connected to the output end of the rotor assembly, the push rod penetrates the first cover plate and forms a sliding connection with the first cover plate, and the screw rod forms a linear transmission connection with the push rod; The second casing includes a hollow casing body, a gear ring formed by an end of the casing body close to the drive assembly being recessed toward an end away from the drive assembly, and a slide rail formed by a recess on the inner circumference of the casing body, wherein the slide rail extends from an end of the casing body away from the drive assembly to an end close to the drive assembly; the gear assembly is supported on a side of the gear ring close to the drive assembly and meshes with the gear ring, and the push rod forms a sliding connection with the slide rail.

2. The linear drive mechanism according to claim 1, characterized in that: The second housing is integrally injection-molded using plastic particles.

3. The linear drive mechanism according to claim 2, characterized in that: 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 under an environment of 23-30°C.

4. The linear drive mechanism according to claim 2, characterized in that: The plastic particles are PEEK-based and contain at least 40% carbon fibers by mass.

5. The linear drive mechanism according to claim 1, characterized in that: One end of the push rod away from the driving assembly is provided with a pin hole formed and penetrated along the radial direction of the push rod.

6. The linear drive mechanism according to claim 1, characterized in that: The transmission assembly also includes a bearing coaxially arranged with the screw rod and welded and fixed to one end of the screw rod close to the driving assembly, and the outer peripheral side of the bearing is fixed to the inner peripheral side of the second housing.

7. The linear drive mechanism according to claim 6, characterized in that: The housing body also includes a plurality of screw hole columns fixed to the outer peripheral side of the bearing and distributed along the axial direction of the bearing, and a plurality of screws pass through the plurality of screw hole columns respectively to fix the bearing in the second housing.

8. The linear drive mechanism according to claim 1, characterized in that: The connecting member comprises a connecting member body fixedly connected to the output end of the rotor assembly and a transmission part formed by extending the connecting member body toward the direction close to the screw rod, and the transmission part is meshed with the gear assembly.

9. The linear drive mechanism according to claim 8, characterized in that: The gear assembly includes a fixed bracket fixed to one end of the screw rod close to the driving assembly, a plurality of fixed columns extended from the fixed bracket toward the driving assembly, and a plurality of gears respectively sleeved on the fixed columns and rotatably connected to the fixed columns, the plurality of gears meshing in sequence and with the gear ring, and one of the gears meshes with the transmission part.

10. The linear drive mechanism according to claim 9, characterized in that: The gears include three gears with different outer diameters, and the three gears are meshed in sequence from small to large.

11. The linear drive mechanism according to claim 1, characterized in that: The slide rail includes a side wall formed by an end of the housing body that is recessed toward an end close to the drive assembly, and a plurality of limiting walls formed by the side wall extending along the radial direction of the push rod. The plurality of limiting walls are spaced apart from each other and tangent to the push rod.

12. The linear drive mechanism according to claim 1, characterized in that: The rotor assembly includes a rotating shaft supported by the first housing and rotatably connected, an iron core sleeved and fixed on the rotating shaft, and a permanent magnet sleeved and fixed on the iron core. The permanent magnet and the stator assembly are spaced apart from each other. The rotating shaft passes through the first housing and is fixedly connected to the connecting member.

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