An electric push rod

Abstract

The application relates to an electric push rod, belonging to the technical field of electric push rods, which comprises a motor, a push rod assembly and a gear transmission mechanism, the gear transmission mechanism comprising a base, a gear transmission assembly, a gear mounting plate and a limiting template, the gear transmission assembly comprising a plurality of gears, the gear mounting plate being arranged in space from the base, the rotating shafts of the gears being respectively supported and positioned between the base and the gear mounting plate, the limiting template being arranged between the base and the gear mounting plate and surrounding part of the outer circumferential side of the gear transmission assembly, and the limiting template being used for limiting the mounting position of the gears. The application improves the problems that the internal positioning structure of the existing electric push rod is complex, the machining precision is relatively high, local size deviation or forming failure occurs, the whole top box is scrapped, the structure is prone to causing the gear shaft center to deviate in the invisible assembly process, and assembly and maintenance are extremely inconvenient.

Description

Technical Field

[0001] This application relates to the field of electric linear actuators, and more particularly to an electric linear actuator. Background Technology

[0002] An electric linear actuator is a drive device that converts the rotary motion of a motor into the linear reciprocating motion of a linear actuator. It is widely used in various mechanical equipment that needs to perform pushing, pulling, and lifting actions. To meet different thrust and operating speed requirements, a gear transmission mechanism is usually set between the motor power output end and the linear actuator assembly to achieve speed reduction and torque increase.

[0003] In existing electric linear actuator structures, gearboxes mostly adopt an integrated housing design. To fix and support the shafts of the internal multi-stage reduction gears, multiple positioning holes or bearing seats corresponding to the gear shafts are often directly cut into the surface of the gearbox's top box or top cover. During assembly, by closing the top box, the internal positioning structure directly engages with the top of each gear shaft, thereby limiting the movement of the gear set.

[0004] However, this traditional structure usually has the following shortcomings in actual production and assembly: The machining and molding of the top box require high precision. Because the top box integrates multiple gear positioning structures, its mold design is relatively complex. During injection molding or machining, if there is a local dimensional deviation or molding error, such as a slight shift in the position of a positioning hole, the entire top box may become unusable, thereby increasing the overall scrap rate and manufacturing costs.

[0005] The assembly process is rather complicated. When the top box is closed downwards to fix the gear set, the operator's view is easily obstructed by the outer shell of the box, making it difficult to visually confirm whether all gear shafts are accurately aligned with the corresponding positioning holes. This increases the assembly difficulty to some extent and can easily lead to gear shaft misalignment or damage from compression.

[0006] Regarding the aforementioned technologies, the inventors believe that the existing electric push rods have a complex internal positioning structure in the top box, which requires high processing precision. Once a local dimensional deviation or molding error occurs, the entire top box will be scrapped. At the same time, this structure is also prone to gear shaft misalignment during the non-visual assembly process, making assembly and maintenance extremely inconvenient. Utility Model Content

[0007] To address the shortcomings of existing electric linear actuators, such as complex internal positioning structures in the top box, high precision requirements, and the risk of scrapping the entire top box due to local dimensional deviations or molding errors, as well as the inconvenience of gear shaft misalignment during non-visual assembly, this application provides an electric linear actuator.

[0008] The electric linear actuator provided in this application adopts the following technical solution: An electric linear actuator includes a motor, a linear actuator assembly, and a gear transmission mechanism disposed between the motor and the linear actuator assembly. The gear transmission mechanism includes a base, a gear transmission assembly, a gear mounting plate, and a limiting template. The gear transmission assembly includes multiple gears. The gear mounting plate is spaced apart from the base. The shaft of each gear is supported and positioned between the base and the gear mounting plate. The limiting template is disposed between the base and the gear mounting plate and surrounds a portion of the outer periphery of the gear transmission assembly. The limiting template also limits the installation position of the gears.

[0009] By adopting the above technical solution, the positioning and support function of the gear is separated from the external packaging structure. This helps to reduce the difficulty of mold manufacturing and the requirements for processing precision of the outer shell such as the top box to a certain extent. This improves the situation where the internal positioning structure of the top box of the existing electric push rod is complex and has high requirements for processing precision. Once a local dimensional deviation or molding error occurs, the entire top box will be scrapped. By setting a limiting template around the outer periphery of the gear transmission component, the necessary circumferential limiting support and installation guidance for each stage of discrete gears can be provided. This is conducive to improving the stability of the gear set during the assembly process and improves the problem that the gear shaft center is easily misaligned during the assembly process that is not visible, making assembly and maintenance extremely inconvenient.

[0010] Preferably, the gear mounting plate further includes an auxiliary support frame located above the gear and disposed between the gear mounting plate and the base. The auxiliary support frame includes multiple bearing support grooves and connecting ribs connecting adjacent bearing support grooves. The shafts of adjacent gears in the gear transmission assembly are respectively positioned and supported in the corresponding bearing support grooves.

[0011] By adopting the above technical solution, the auxiliary support frame set between the gear mounting plate and the base is used to connect multiple bearing support grooves on it into one piece through connecting ribs to support the gear shaft, and the gear shaft is independently fixed to the gear mounting plate through mounting ears with fastening holes, which to a certain extent helps to maintain relatively accurate meshing between multi-stage gears.

[0012] Preferably, the auxiliary support frame has outwardly extending mounting ears on its edge, and fastening holes are provided on the mounting ears. The auxiliary support frame is independently fixed to the gear mounting plate by fasteners passing through the fastening holes.

[0013] Preferably, the base is provided with a bearing bearing groove corresponding to the bearing support groove position, and the two ends of the rotating shaft are rotatably installed in the corresponding bearing support groove and bearing bearing groove, respectively.

[0014] By adopting the above technical solution, the bearing support groove and the bearing bearing bearing groove cooperate to rotatably support both ends of each gear shaft between them, thereby achieving bidirectional limitation and reliable support for both ends of the gear shaft.

[0015] Preferably, the electric push rod further includes a top box covering the gear transmission mechanism, the top box having a receiving cavity, and the gear transmission assembly, gear mounting plate, and limiting template all being housed between the receiving cavity and the base.

[0016] Preferably, there is a clearance between the inner wall of the top box and the top of the shaft of each gear in the gear transmission assembly.

[0017] By adopting the above technical solution, there is a clearance between the inner wall of the top box and the top of the shaft of each gear, which simplifies the function of the top box to external physical protection and enclosure, removes the assembly positioning constraint of the top box on the internal gear set, and to a certain extent helps to improve the assembly fault tolerance during the assembly of the top box.

[0018] Preferably, the plurality of gears include a primary gear connected to the motor drive, at least one intermediate gear, and an output main gear connected to the push rod assembly. The gear mounting plate covers the primary gear and the intermediate gear, and at least a portion of the structure of the output main gear extends upward through the gear mounting plate.

[0019] Preferably, the gear mounting plate is provided with a positioning and mating hole coaxial with the output main gear, the bottom of the push rod assembly passes through the positioning and mating hole, and the bottom of the push rod assembly is fixed to the gear mounting plate by bolts.

[0020] Preferably, the top box is provided with a connecting cylinder coaxial with the positioning and mating hole, the bottom of the connecting cylinder is provided with a through opening, and the bottom of the push rod assembly extends out of the opening at the bottom of the connecting cylinder.

[0021] Preferably, the main body of the motor is arranged parallel to the main axis of the push rod assembly, the output end of the motor is fixedly connected to one side of the bottom surface of the base, and the power shaft of the motor passes through the base from bottom to top and enters the gear transmission mechanism.

[0022] In summary, this application includes at least one of the following beneficial technical effects: Because the gear mounting plate and base are set independently of the top box, and the gears are directly supported and positioned on the limiting template and gear mounting plate, there is a clearance between the inner wall of the top box and the top of the shaft of each gear. The positioning and support function of the gears is effectively separated from the external packaging structure, which helps to reduce the mold manufacturing difficulty and processing accuracy requirements of the top box and other external shells. It improves the complex internal positioning structure of the existing electric push rod top box, which has high processing accuracy requirements. Once a local dimensional deviation or molding error occurs, the entire top box is prone to being scrapped. By setting a limiting template, intuitive circumferential limiting support and installation guidance can be provided for each level of gears before the external structure of the top box is closed. This helps to improve the visibility and alignment convenience of the gears during the assembly process. It also improves the situation that in the past, when closing a top box with a complex positioning structure, it was difficult to confirm the alignment due to blind spots in the assembly process, which could easily lead to gear shaft offset, crushing damage, and inconvenience in assembly and maintenance during the non-visual assembly process. By using an auxiliary support frame set between the gear mounting plate and the base, multiple bearing support grooves on it are connected together by connecting ribs, and then independently fixed to the gear mounting plate by mounting ears with fastening holes. This enhances the radial limiting and coordinated support of the internal multi-stage gears during assembly and operation, and helps to maintain a relatively accurate meshing state between the multi-stage gears. Attached Figure Description

[0023] Figure 1 This is a perspective view of the overall appearance of the electric actuator in the embodiment of this application.

[0024] Figure 2 This is a schematic diagram of the internal structure of the electric actuator after the top box is removed in an embodiment of this application.

[0025] Figure 3 This is a front view of the gear mounting plate in an embodiment of this application.

[0026] Figure 4 This is a schematic diagram of the internal structure of the electric actuator after the gear mounting plate has been further removed in the embodiment of this application.

[0027] Figure 5 This is a schematic diagram of the auxiliary support frame in an embodiment of this application.

[0028] Figure 6 This is a three-dimensional structural diagram of the limiting template in the embodiments of this application.

[0029] Figure 7 This is a top view of the base structure in an embodiment of this application.

[0030] Figure 8 This is a three-dimensional structural diagram of the top box in an embodiment of this application.

[0031] Explanation of reference numerals in the attached drawings: 1. Motor; 2. Push rod assembly; 3. Gear transmission mechanism; 4. Base; 5. Connecting cylinder; 6. Gear mounting plate; 7. Limiting template; 8. Push rod body; 9. Rotating shaft; 10. Auxiliary support frame; 11. Bearing support groove; 12. Connecting rib; 13. Mounting ear; 14. Fastening hole; 15. Bottom of push rod; 16. Bearing bearing groove; 17. Top box; 18. Accommodating cavity; 19. Primary gear; 20. Intermediate gear; 21. Output main gear; 22. Positioning mating hole. Detailed Implementation

[0032] The following is in conjunction with the appendix Figure 1-8 This application will be described in further detail.

[0033] This application discloses an electric linear actuator. (Refer to...) Figure 1 The device includes a motor 1, a push rod assembly 2, and a gear transmission mechanism 3 disposed between the motor 1 and the push rod assembly 2. The gear transmission mechanism 3 includes a base 4, a gear transmission assembly, a gear mounting plate 6, and a limiting template 7. The gear transmission assembly includes multiple gears. The gear mounting plate 6 and the base 4 are spaced apart. The rotating shaft 9 of each gear is supported and positioned between the base 4 and the gear mounting plate 6. The limiting template 7 is fixed on the base 4 and surrounds part of the outer periphery of the gear transmission assembly. The limiting template 7 is also used to limit the installation position of the gears.

[0034] The push rod assembly 2 includes a push rod body 8 and a push rod bottom 15. The push rod body 8 is the working part that performs linear push-pull or lifting actions. The push rod body 8 typically includes an outer tube, an inner tube slidably fitted inside the outer tube, and a lead screw drive mechanism built into the inner tube. When receiving rotational power, the lead screw drive mechanism inside the push rod body 8 converts the rotational motion into linear reciprocating motion of the inner tube along the axial direction.

[0035] The push rod bottom 15 is a key component for connection and force bearing, mainly consisting of a push rod connecting seat. The inner side of the push rod bottom 15 is connected to the lead screw transmission mechanism inside the push rod body 8 to receive rotational power from the output main gear 21; the outer side of the push rod bottom 15 extends downward through the opening of the connecting cylinder 5 on the top box 17 and is coaxially inserted and aligned with the positioning mating hole 22 on the gear mounting plate 6. Finally, the push rod bottom 15 is directly locked and fixed to the gear mounting plate 6 by multiple bolts, thereby achieving direct fixation between the push rod assembly 2 and the internal rigid frame of the gear transmission mechanism 3.

[0036] The gear mounting plate 6 also includes an auxiliary support frame 10, which is located above the gear and is positioned between the gear mounting plate 6 and the base 4. The auxiliary support frame 10 includes multiple bearing support grooves 11 and connecting ribs 12 that connect adjacent bearing support grooves 11. The shafts 9 of adjacent gears in the gear transmission assembly are respectively positioned and supported in the corresponding bearing support grooves 11.

[0037] The auxiliary support frame 10 has outwardly extending mounting ears 13 on its edge, and fastening holes 14 are provided on the mounting ears 13. The auxiliary support frame 10 is independently fixed to the gear mounting plate 6 by fasteners passing through the fastening holes 14.

[0038] The base 4 is provided with a bearing support groove 16 corresponding to the position of the bearing support groove 11. The two ends of the rotating shaft 9 are rotatably installed in the corresponding bearing support groove 11 and bearing support groove 16, respectively.

[0039] The electric push rod also includes a top box 17 covering the outside of the gear transmission mechanism 3. The top box 17 has a receiving cavity 18, and the gear transmission assembly, gear mounting plate 6 and limiting template 7 are all housed between the receiving cavity 18 and the base 4.

[0040] There is a clearance between the inner wall of the top box 17 and the top of the shaft 9 of each gear in the gear transmission assembly.

[0041] The gear transmission assembly also includes a primary gear 19 connected to the motor 1, at least one intermediate gear 20, and an output main gear 21 connected to the push rod assembly 2. The gear mounting plate 6 covers the primary gear 19 and the intermediate gear 20, and at least a portion of the structure of the output main gear 21 extends upward through the gear mounting plate 6.

[0042] The main body of motor 1 and the axis of push rod body 8 are arranged in parallel. The output end of motor 1 is fixedly connected to one side of the bottom surface of base 4. The power shaft of motor 1 passes through base 4 from bottom to top and enters gear transmission mechanism 3.

[0043] The implementation principle of an electric actuator according to an embodiment of this application is as follows: First, a limiting template 7 is pre-fixed on a base 4 to form an installation enclosure with a specific internal contour above the base 4. Then, the primary gear 19, intermediate gears 20 at each stage, and the output main gear 21 are sequentially placed onto the base 4. During placement, the inner wall contour of the limiting template 7 is used to radially limit and guide the installation alignment of each gear. Next, an auxiliary support frame 10 is installed above the intermediate gear 20, so that its bearing support groove 11 engages with the corresponding gear's shaft 9, forming a local rigid interconnection. Then, a gear mounting plate 6 is placed over the gear transmission assembly and locked in place with fasteners, so that the shafts 9 of each gear are rotatably supported and positioned between the base 4 and the gear mounting plate 6, thereby constructing a relatively independent and structurally stable gear transmission mechanism 3 internally. Bolts are used as fasteners.

[0044] After the internal gear transmission mechanism 3 is fixed, the bottom end of the lead screw inside the push rod connecting seat passes downward through the center of the push rod connecting seat and completes coaxial insertion with the transmission hole at the center of the output main gear 21 located below the gear mounting plate 6. After the docking is completed, the top box 17 is fastened and fastened directly onto the internal gear mounting plate 6 by fasteners passing through the push rod connecting seat and the top box 17.

[0045] In actual operation, the motor 1, which is arranged parallel to the push rod body 8, starts, and its power shaft drives the primary gear 19 located in the gear transmission mechanism 3 to rotate from bottom to top. This rotational power is transmitted sequentially through the primary gear 19 to the intermediate gears 20 of each stage, which are supported by the auxiliary support frame 10 and the limiting template 7, and finally to the output main gear 21. During this high-speed transmission process, the internal support frame composed of the base 4, the limiting template 7, the auxiliary support frame 10, and the gear mounting plate 6 helps to distribute the lateral forces and vibrations on the gears to a certain extent, maintaining the relative stability of the gear shaft spacing and meshing state of each stage.

[0046] The output main gear 21 drives the bottom end of the lead screw, which is coaxially inserted with it, to rotate synchronously. The rotational power is thus smoothly input into the push rod body 8, driving the internal lead screw to rotate, which in turn drives the lead screw nut and inner tube, which are restricted from circumferential rotation, to perform axial linear reciprocating motion, thereby executing the push-pull or lifting action of the target equipment. During this operation and under external load, since the push rod connecting seat is directly locked to the gear mounting plate 6, the axial thrust and reaction force generated by the push rod can directly bypass the top box 17 and be transmitted to the internal support frame with higher rigidity. This allows the top box 17 to only perform the function of external physical protection without participating in the core load, thereby improving the overall structural stability of the equipment when operating under heavy load.

[0047] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An electric linear actuator, comprising a motor (1), a linear actuator assembly (2), and a gear transmission mechanism (3) disposed between the motor (1) and the linear actuator assembly (2); characterized in that: The gear transmission mechanism (3) includes a base (4), a gear transmission assembly, a gear mounting plate (6), and a limiting template (7). The gear transmission assembly includes multiple gears. The gear mounting plate (6) is spaced apart from the base (4). The shaft (9) of the gear is supported and positioned between the base (4) and the gear mounting plate (6). The limiting template (7) is disposed between the base (4) and the gear mounting plate (6), and the limiting template (7) surrounds part of the outer periphery of the gear transmission assembly. The limiting template (7) is also used to limit the installation position of the gear.

2. The electric linear actuator according to claim 1, characterized in that: The gear mounting plate (6) also includes an auxiliary support frame (10), which is located above the gear and is disposed between the gear mounting plate (6) and the base (4). The auxiliary support frame (10) includes multiple bearing support grooves (11) and connecting ribs (12) connecting adjacent bearing support grooves (11). The shafts (9) of adjacent gears in the gear transmission assembly are respectively positioned and supported in the corresponding bearing support grooves (11).

3. The electric linear actuator according to claim 2, characterized in that: The auxiliary support frame (10) has outwardly extending mounting ears (13) on its edge. The mounting ears (13) have fastening holes (14). The auxiliary support frame (10) is fixed to the gear mounting plate (6) by fasteners passing through the fastening holes (14).

4. The electric linear actuator according to claim 3, characterized in that: The base (4) is provided with a bearing support groove (16) corresponding to the position of the bearing support groove (11), and the two ends of the rotating shaft (9) are rotatably installed in the corresponding bearing support groove (11) and bearing support groove (16).

5. The electric linear actuator according to claim 1, characterized in that: The electric push rod also includes a top box (17) covering the outside of the gear transmission mechanism (3). The top box (17) has a receiving cavity (18). The gear transmission assembly, gear mounting plate (6) and limiting template (7) are all housed between the receiving cavity (18) and the base (4).

6. The electric actuator according to claim 5, characterized in that: There is a clearance between the inner wall of the top box (17) and the top of the shaft (9) of each gear in the gear transmission assembly.

7. The electric linear actuator according to claim 6, characterized in that: The plurality of gears include a primary gear (19) connected to the motor (1), at least one intermediate gear (20), and an output main gear (21) connected to the push rod assembly (2). The gear mounting plate (6) covers the primary gear (19) and the intermediate gear (20), and at least a portion of the structure of the output main gear (21) extends upward through the gear mounting plate (6).

8. The electric linear actuator according to claim 7, characterized in that: The gear mounting plate (6) is provided with a positioning and mating hole (22) coaxial with the output main gear (21). The bottom of the push rod assembly (2) passes through the positioning and mating hole (22), and the bottom of the push rod assembly (2) is fixed to the gear mounting plate (6) by bolts.

9. The electric linear actuator according to claim 8, characterized in that: The top box (17) is provided with a connecting cylinder (5) coaxial with the positioning mating hole (22). The bottom of the connecting cylinder (5) is provided with a through opening, and the bottom of the push rod assembly (2) passes through the opening at the bottom of the connecting cylinder (5).

10. The electric linear actuator according to claim 1, characterized in that: The main body of the motor (1) is arranged parallel to the main axis of the push rod assembly (2). The output end of the motor (1) is fixedly connected to one side of the bottom surface of the base (4). The power shaft of the motor (1) passes through the base (4) from bottom to top and enters the gear transmission mechanism (3).

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