Electric push rod

Abstract

According to the electric push rod, a worm is installed at the output end of a driving motor and meshed with a turbine, internal threads are formed on the inner circumferential wall of the turbine, the turbine is arranged on a lead screw in a sleeving mode and is in threaded connection with the lead screw through the internal threads, and internal threads in threaded connection with the lead screw are formed on the inner circumferential walls of an upper extending part and a lower extending part of an inner ring of the turbine; a horizontal stress face is formed on the periphery of the lower edge of the upper extending part, an upper bearing is installed on the periphery of the upper extending part, a lower bearing is installed on the periphery of the lower extending part, the upper bearing is supported on the horizontal stress face, and the upper bearing and the lower bearing are both limited in the push rod installation base. According to the electric push rod, through the integrated design of the turbine and the nut, stress can be improved, the periphery of the turbine is evenly stressed, on one hand, the original space occupied by the nut is reduced, on the other hand, the lead screw does not need to rotate, rotary swing is eliminated, and then uneven resistance caused by deflection of the lead screw is eliminated; the double-bearing supporting and limiting structure can improve the meshing quality of the worm and the turbine and eliminate abnormal noise.

Description

Technical Field

[0001] This utility model relates to the field of actuator technology, and in particular to an electric actuator. Background Technology

[0002] Traditional electric linear actuators typically use gears or worm gears to reduce speed and drive a lead screw and nut mechanism. The rotation of the lead screw drives the translation of the nut, which in turn drives the load. Traditional electric linear actuators employ a two-stage mechanism with distinct layers, each requiring corresponding components to function. This results in at least four core transmission components: worm gear, worm wheel, lead screw, and nut. The space occupied by this mechanism is unsuitable for applications in confined spaces. The lead screw is a machined part, and straightness deviations exist. The bending of the lead screw is amplified during rotation, manifesting as yaw during rotation, causing uneven resistance. In severe cases, it can cause the worm wheel to wobble, affecting worm gear engagement and generating noise. Actuators are generally fixed with screws; if the external components or the fixing parts shift, the actuator risks jamming. Furthermore, the traditional design using the nut as the force output interface, whether through threads or a separate external structure on the nut, suffers from uneven force distribution and localized stress concentration. Moreover, the structure connecting to the external interface of the electric linear actuator is not necessarily a standard shape, and may be deformed or angularly misaligned. In summary, when improving electric linear actuators, it is necessary to consider how to simplify the mechanism, reduce space occupation to meet the needs of installation in confined spaces, how to improve the risk of uneven resistance and abnormal noise caused by sway, and how to improve installation applicability and improve the fault tolerance of use. Utility Model Content

[0003] The first technical problem to be solved by this utility model is to provide an electric push rod that integrates a turbine and a nut into one structure, which can eliminate the swing of the lead screw and reduce abnormal noise, in view of the above-mentioned existing technology.

[0004] The second technical problem to be solved by this utility model is to provide an electric push rod that can improve the applicability of installation, in view of the above-mentioned existing technology.

[0005] The technical solution adopted by this utility model to solve the first technical problem mentioned above is as follows: the electric push rod includes a lead screw, a worm gear, and a drive motor. A worm gear is installed at the output end of the drive motor, and the worm gear meshes with the worm gear. The characteristic is that: an internal thread is formed on the inner peripheral wall of the worm gear, the worm gear is sleeved on the lead screw and threadedly connected to the lead screw through the internal thread, the inner ring of the worm gear has an upper extension and a lower extension, the upper extension and the lower extension are interconnected, and an internal thread is formed on the inner peripheral wall of the upper extension and the lower extension to be threadedly connected to the lead screw. A horizontal force-bearing surface is formed on the outer periphery of the lower edge of the upper extension, an upper bearing is installed on the outer periphery of the upper extension, a lower bearing is installed on the outer periphery of the lower extension, the upper bearing is supported on the horizontal force-bearing surface, and both the upper bearing and the lower bearing are limited within the push rod mounting seat.

[0006] The technical solution adopted by this utility model to solve the second technical problem mentioned above is as follows: The electric push rod further includes an upper mounting bracket mounted on the push rod mounting seat. The mounting wall of the push rod mounting seat has screw holes, and the mounting wall of the upper mounting bracket has mounting holes corresponding to the screw holes. A first arc-shaped protrusion is provided on the side of the mounting wall of the push rod mounting seat facing the upper mounting bracket. The mounting wall of the upper mounting bracket abuts against the first arc-shaped protrusion. Fastening screws pass through the screw holes and mounting holes in sequence to connect and fix the upper mounting bracket to the push rod mounting seat. With this configuration, by providing an arc-shaped protrusion protruding from the mounting surface on the screw fastening surface of the upper interface, even if the mounting surface of the upper connector is angularly misaligned during installation, the push rod can still be installed vertically, and the screws can still be fixed perpendicular to the mounting surface without generating bending stress when tightened.

[0007] More preferably, the first arc-shaped protrusion is a cylindrical structure located on the edge of the screw hole and extending away from the screw hole.

[0008] In order to position the push rod mounting base on the upper mounting bracket, the mounting wall of the upper mounting bracket has a positioning hole, which is located above the mounting hole. The top of the push rod mounting base has a hanging wall, which is inserted into the positioning hole.

[0009] Further preferably, the mounting wall of the push rod mounting base has a second arc-shaped protrusion protruding towards the side of the fastening screw, and a pad is provided between the head of the fastening screw and the mounting wall of the push rod mounting base, the pad abutting against the second arc-shaped protrusion. This configuration, by designing a fault-tolerant structure at the connection and fixing interface between the electric push rod and the external environment, improves the applicability to dimensional deviations or deformations of external connection components.

[0010] In a further preferred embodiment, the electric actuator also includes a lead screw mounting base, which is located below the actuator mounting base, and the lower end of the lead screw is mounted on the lead screw mounting base.

[0011] To further improve installation applicability and fault tolerance, the lead screw mounting base includes an outer shell and a force-bearing body confined within the outer shell. The upper surface of the force-bearing body is spherical. By designing the force-bearing surface as a sphere, when the angle of the lower mounting bracket's force application surface is skewed, the force point gradually moves outwards. Compared to a planar force-bearing surface, the force point will immediately move to the outermost edge, improving the stress on the center of force application and enhancing safety.

[0012] Further preferably, it also includes a lower base, the bottom of which has a bayonet, the outer shell is fitted into the bayonet, and the lower base is fixed to the load by screws.

[0013] As a preferred embodiment of any of the above schemes, the lead screw is set vertically and the worm gear is set horizontally, and the worm gear moves up and down along the lead screw under the drive of the drive motor.

[0014] Compared with the prior art, the advantages of this utility model are as follows: the inner circumferential wall of the electric push rod is formed with internal threads, the push rod is sleeved on the lead screw and connected to the lead screw through internal threads, the inner circumferential walls of the upper and lower extensions of the inner ring of the push rod are formed with internal threads that are connected to the lead screw, and the upper bearing on the outer circumference of the upper extension and the lower bearing on the outer circumference of the lower extension are both limited in the push rod mounting seat, and the upper bearing is supported on the horizontal force-bearing surface. By integrating the push rod and the nut into one design, the force distribution can be improved, so that the push rod is evenly stressed around the circumference, and the force direction is all positive pressure, thereby improving the safety factor of the parts. The space occupied by the original nut is reduced, and the original limiting and fasteners of the worm gear and screw are eliminated, realizing a reduction in the size of the mechanism in the direction of movement. On the other hand, after the nut and worm gear are integrated, they rotate actively with the worm gear, and the screw acts as the driven part. This eliminates the need for the screw to rotate, thus eliminating rotational oscillation and the uneven resistance caused by screw wobble. Another advantage of the screw not rotating is that it does not cause repeated oscillation of the worm gear, which can improve the meshing quality of the worm gear and the worm and reduce abnormal noise. In addition, the use of a double bearing support limiting structure further improves the meshing quality of the worm and the worm and eliminates abnormal noise. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the electric actuator according to an embodiment of the present invention.

[0016] Figure 2 for Figure 1 The structural cross-sectional view of the electric actuator shown;

[0017] Figure 3 for Figure 1 A partially exploded view of the electric linear actuator shown.

[0018] Figure 4 for Figure 1Another structural cross-sectional view of the electric linear actuator shown;

[0019] Figure 5 This is a schematic diagram of the push rod mounting base according to an embodiment of the present utility model;

[0020] Figure 6 This is a schematic diagram of the upper mounting bracket according to an embodiment of the present utility model;

[0021] Figure 7 This is a schematic diagram of the turbine structure according to an embodiment of the present invention;

[0022] Figure 8 This is a schematic diagram of the installation of the turbine, upper bearing, and lower bearing according to an embodiment of the present invention. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0024] like Figures 1 to 8 As shown, the electric actuator of this embodiment includes a lead screw 1, a worm gear 2, and a drive motor 3. A worm gear 4 is installed at the output end of the drive motor 3, and the worm gear 4 meshes with the worm gear 2. The lead screw 1 is vertically arranged, and the worm gear 4 is horizontally arranged. Under the drive of the drive motor 3, the worm gear 2 moves up and down along the lead screw 1. The inner ring of the worm gear 2 has an upper extension 21 and a lower extension 22, which are interconnected. An internal thread 24 is formed on the inner peripheral wall of the worm gear 2 to connect with the lead screw 1. An internal thread 24 is also formed on the inner peripheral walls of the upper extension 21 and the lower extension 22 to connect with the lead screw 1. The worm gear 2 is sleeved on the lead screw 1 and connected to the lead screw 1 by the internal thread 24. That is, the worm gear 2 and the nut are integrated into one design, eliminating the auxiliary connecting parts between traditional transmission mechanisms and the space occupied by the original nut, realizing the reduction of the size in the direction of movement of the mechanism and meeting the requirements of installation in narrow spaces. Furthermore, after the nut and turbine 2 are integrated, they rotate actively with the turbine. The lead screw 1 acts as the driven component, which eliminates the need for the lead screw 1 to rotate, thereby eliminating rotational oscillation and the uneven resistance caused by the oscillation of the lead screw 1.

[0025] A horizontal force-bearing surface 23 is formed on the outer periphery of the lower edge of the upper extension 21. An upper bearing 51 is installed on the outer periphery of the upper extension 21, and a lower bearing 52 is installed on the outer periphery of the lower extension 22. The upper bearing 51 is supported on the horizontal force-bearing surface 23, and both the upper bearing 51 and the lower bearing 52 are confined within the push rod mounting seat 6. This improves the force distribution, ensuring that the turbine 2 is evenly stressed around its periphery, with all forces acting as positive pressure, thus increasing the safety factor of the components. Furthermore, the use of a double bearing support and confining structure further improves the meshing quality of the worm and turbine, eliminating abnormal noise.

[0026] In this embodiment, the upper mounting bracket 7 is mounted on the push rod mounting base 6. Specifically, the mounting wall of the push rod mounting base 6 has screw holes 61, and there are three mounting walls of the push rod mounting base 6 arranged in a triangular pattern. Each mounting wall has a screw hole 61 at its top. The mounting wall of the upper mounting bracket 7 has mounting holes 71 corresponding to the screw holes 61. A first arc-shaped protrusion 62 protrudes from the side of the mounting wall of the push rod mounting base 6 facing the upper mounting bracket 7. The mounting wall of the upper mounting bracket 7 abuts against the first arc-shaped protrusion 62. The fastening screw 8 passes through the screw holes 61 and the mounting holes 71 in sequence to connect and fix the upper mounting bracket 7 to the push rod mounting base 6. In this embodiment, the first arc-shaped protrusion 62 is a cylindrical structure located at the edge of the screw hole 61 and extending away from the screw hole 61. The mounting wall of the push rod mounting base 6 has a second arc-shaped protrusion 64 protruding from the side facing the fastening screw 8. The second arc-shaped protrusion 64 also has a cylindrical structure. A pad 9 is provided between the head of the fastening screw 8 and the mounting wall of the push rod mounting base 6, and the pad 9 abuts against the second arc-shaped protrusion 64. By providing a cylindrical structure protruding from the mounting surface on the screw fastening surface of the push rod mounting base 6, the push rod can still be installed vertically even if the mounting surface of the upper mounting bracket 7 is angularly deviated during installation, and the screw can still be fixed perpendicular to the mounting surface without generating bending stress when tightened. This prevents additional stress on the internal components of the push rod when a load is applied from below, improving reliability.

[0027] In addition, the mounting wall of the upper mounting bracket 7 has a positioning hole 72, which is located above the mounting hole 71. The top of the push rod mounting base 6 has a hanging wall 63, which is inserted into the positioning hole 72 during installation.

[0028] In this embodiment, a lead screw mounting base 10 is provided below the push rod mounting base 6. The push rod mounting base 6 constitutes the upper interface of the electric push rod, and the lead screw mounting base 10 constitutes the lower interface of the electric push rod. The lower end of the lead screw 1 is mounted on the lead screw mounting base 10. The lead screw mounting base 10 includes a housing 101 and a force-bearing body 102 limited inside the housing 101. The upper surface of the force-bearing body 102 is spherical. By designing the force-bearing surface as a spherical surface, when the angle of the force-bearing surface of the lower interface is skewed, the force point gradually moves to the outer periphery. Compared with a planar force-bearing surface, the force point will immediately move to the outermost side, improving the stress generated at the center of the force and improving safety. In addition, the bottom of the lower base 11 has a bayonet 111, and the housing 101 is embedded in the bayonet 111. The lower base 11 is connected and fixed to the load by screws 12.

[0029] In the specification and claims of this utility model, terms indicating direction, such as "front," "rear," "upper," "lower," "left," "right," "side," "top," and "bottom," are used to describe various exemplary structural parts and elements of this utility model. However, the use of these terms is merely for the purpose of explanation and is based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in this utility model can be arranged in different orientations, these terms indicating direction are for illustrative purposes only and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

Claims

1. An electric actuator, comprising a lead screw (1), a worm gear (2), and a drive motor (3), wherein a worm (4) is mounted on the output end of the drive motor (3), the worm gear (4) meshing with the worm gear (2), characterized in that: The inner circumferential wall of the turbine (2) is formed with an internal thread (24). The turbine (2) is sleeved on the lead screw (1) and is threadedly connected to the lead screw (1) through the internal thread (24). The inner ring of the turbine (2) has an upper extension (21) and a lower extension (22). The upper extension (21) and the lower extension (22) are interconnected. The inner circumferential wall of the upper extension (21) and the lower extension (22) is formed with an internal thread (24) that is threadedly connected to the lead screw (1). The outer periphery of the lower edge of the upper extension (21) forms a horizontal force-bearing surface (23). An upper bearing (51) is installed on the outer periphery of the upper extension (21), and a lower bearing (52) is installed on the outer periphery of the lower extension (22). The upper bearing (51) is supported on the horizontal force-bearing surface (23). Both the upper bearing (51) and the lower bearing (52) are limited within the push rod mounting seat (6).

2. The electric linear actuator according to claim 1, characterized in that: It also includes an upper mounting bracket (7) mounted on the push rod mounting base (6). The mounting wall of the push rod mounting base (6) has screw holes (61), and the mounting wall of the upper mounting bracket (7) has mounting holes (71) corresponding to the screw holes (61). A first arc-shaped protrusion (62) is provided on the side of the mounting wall of the push rod mounting base (6) facing the upper mounting bracket (7). The mounting wall of the upper mounting bracket (7) abuts against the first arc-shaped protrusion (62). Fastening screws (8) pass through the screw holes (61) and the mounting holes (71) in sequence to connect and fix the upper mounting bracket (7) to the push rod mounting base (6).

3. The electric linear actuator according to claim 2, characterized in that: The first arc-shaped protrusion (62) is a cylindrical structure located on the edge of the screw hole (61) and extending away from the screw hole (61).

4. The electric linear actuator according to claim 2, characterized in that: The mounting wall of the upper mounting bracket (7) has a positioning hole (72) located above the mounting hole (71). The top of the push rod mounting base (6) has a hanging wall (63) inserted into the positioning hole (72).

5. The electric actuator according to claim 2, characterized in that: The push rod mounting base (6) has three mounting walls arranged in a triangular pattern, and each mounting wall has a screw hole (61) at its top.

6. The electric linear actuator according to claim 1, characterized in that: The mounting wall of the push rod mounting base (6) has a second arc-shaped protrusion (64) protruding from the side facing the fastening screw (8). A pad (9) is provided between the head of the fastening screw (8) and the mounting wall of the push rod mounting base (6), and the pad (9) abuts against the second arc-shaped protrusion (64).

7. The electric linear actuator according to claim 1, characterized in that: It also includes a lead screw mounting base (10), which is located below the push rod mounting base (6), and the lower end of the lead screw (1) is mounted on the lead screw mounting base (10).

8. The electric linear actuator according to claim 7, characterized in that: The lead screw mounting base (10) includes an outer shell (101) and a force-bearing body (102) limited inside the outer shell (101), the upper surface of the force-bearing body (102) being spherical.

9. The electric linear actuator according to claim 8, characterized in that: It also includes a lower base (11), the bottom of which has a bayonet (111), the outer shell (101) is embedded in the bayonet (111), and the lower base (11) is connected and fixed to the load by screws (12).

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