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] The invention relates to the technical field of drivers, in particular to an electric push rod. Background Art

[0002] Traditional electric push rods generally drive the screw nut mechanism of the actuator through the deceleration of gears or worms, and use the rotation of the screw to drive the translation of the nut, and then use the nut to drive the load. Traditional electric push rods use a two-level mechanism with distinct levels and need corresponding parts to realize the function. In this way, at least four core transmission components are required, namely worm, turbine, screw, and nut. The space occupied by the mechanism cannot meet the use requirements of small spaces. The screw is a machined part with straightness deviation. The bending amount of the screw will be magnified in the middle or at both ends when it rotates, which is manifested as deflection during rotation and uneven resistance. What's more, it drives the turbine to deflect, affects the meshing of the worm, and produces abnormal noise. Generally, the push rod is fixed by screws. If the external part and the fixed part are offset, the push rod will be at risk of being stuck. In addition, the traditional design of using nuts as the output interface of force, whether through threads or peripheral structures set on the nut, has the phenomenon of uneven force and local stress concentration, and the structure connected to the external interface of the electric push rod is not necessarily a standard shape, and there are deformations, angle deviations, etc. To sum up, when improving the electric linear actuator, it is necessary to consider how to streamline the mechanism, reduce space occupancy to meet the needs of installation in a small space, how to improve the risk of uneven resistance and abnormal noise caused by yaw, and how to improve installation applicability and improve fault tolerance. Summary of the invention

[0003] The first technical problem to be solved by the present invention is to provide an electric push rod with a turbine and a nut as an integrated structure, which can eliminate the rotation and swing of the screw rod and reduce abnormal noise in response to the above-mentioned existing technical status.

[0004] The second technical problem to be solved by the present invention is to provide an electric push rod that can improve the installation applicability in view of the above-mentioned existing technical status.

[0005] The technical solution adopted by the present invention to solve the first technical problem mentioned above is as follows: the electric push rod includes a screw, a turbine and a driving motor, a worm is installed at the output end of the driving motor, and the worm is meshed with the turbine, and is characterized in that: an internal thread is formed on the inner circumferential wall of the turbine, the turbine is sleeved on the screw and is threadedly connected to the screw through the internal thread, the inner ring of the turbine has an upper extension part and a lower extension part, the upper extension part and the lower extension part are interconnected, and an internal thread threadedly connected to the screw is formed on the inner circumferential wall of the upper extension part and the lower extension part, a horizontal force-bearing surface is formed on the outer periphery of the lower edge of the upper extension part, an upper bearing is installed on the outer periphery of the upper extension part, and a lower bearing is installed on the outer periphery of the lower extension part, the upper bearing is supported on the horizontal force-bearing surface, and the upper bearing and the lower bearing are both limited in the push rod mounting seat.

[0006] The technical solution adopted by the present invention to solve the above-mentioned second technical problem is as follows: the electric push rod also includes an upper mounting bracket installed on the push rod mounting seat, a screw hole is opened on the mounting wall of the push rod mounting seat, a mounting hole corresponding to the screw hole is opened on the mounting wall of the upper mounting bracket, a first arc-shaped protrusion is convexly 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, and the fastening screw passes through the screw hole and the mounting hole in sequence to connect and fix the upper mounting bracket to the push rod mounting seat. In this way, 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 connecting member is angularly deflected during installation, the push rod can still be kept installed vertically, and the screw can still be fixed perpendicular to the mounting surface when tightened without generating bending stress.

[0007] Further preferably, the first arc-shaped protrusion is a cylindrical structure provided at the edge of the screw hole and extending in a direction away from the screw hole.

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

[0009] Further preferably, the mounting wall of the push rod mounting seat is provided with a second arc-shaped protrusion on the side facing the fastening screw, and a cushion block is provided between the head of the fastening screw and the mounting wall of the push rod mounting seat, and the cushion block abuts against the second arc-shaped protrusion. In this way, by designing a fault-tolerant structure on the connection and fixing interface between the electric push rod and the outside world, the applicability to the dimensional deviation or deformation of the external connection parts can be improved.

[0010] Further preferably, the electric push rod also includes a screw rod mounting seat, the screw rod mounting seat is arranged below the push rod mounting seat, and the lower end of the screw rod is mounted on the screw rod mounting seat.

[0011] In order to further improve the applicability of installation and the fault tolerance, the screw mounting seat includes an outer shell and a force-bearing body limited inside the outer shell, and the upper surface of the force-bearing body is a spherical surface. By designing the force-bearing surface as a spherical surface, when the angle of the force-applying surface of the lower mounting frame is skewed, the force-bearing point gradually moves to the periphery. Compared with the flat force-bearing surface, the force-bearing point will immediately move to the outermost side, thereby improving the stress generated on the force center position and improving safety.

[0012] Further preferably, it further comprises a lower base, the bottom of the lower base has a bayonet, the outer shell is embedded in the bayonet, and the lower base is fixed to the load by screw connection.

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

[0014] Compared with the prior art, the advantages of the present invention are as follows: an internal thread is formed on the inner circumferential wall of the turbine of the electric push rod, the turbine sleeve is arranged on the screw rod and is threadedly connected with the screw rod through the internal thread, the inner circumferential wall of the upper extension part and the lower extension part of the inner ring of the turbine are formed with internal threads threadedly connected with the screw rod, and the upper bearing on the outer periphery of the upper extension part and the lower bearing on the outer periphery of the lower extension part are both limited in the push rod mounting seat, and the upper bearing is supported on the horizontal force-bearing surface. By integrating the turbine and the nut into an integrated design, the force can be improved, so that the turbine is evenly stressed all around, and the force direction is positive pressure, thereby improving the safety factor of the parts and reducing the friction between the turbine and the nut. The space occupied by the original nut is reduced, and the limiters and fasteners of the original turbine and screw are eliminated, thereby reducing the size of the mechanism in the direction of movement. On the other hand, after the nut and turbine are integrated, they actively rotate with the turbine, and the screw serves as a driven part, so that the screw does not need to rotate, eliminating rotational swing, and then eliminating the uneven resistance caused by the screw eccentricity. Another advantage of the screw not rotating is that it will not cause repeated swing of the turbine, which can improve the meshing quality of the turbine and the worm and reduce abnormal noise. In addition, a double-bearing support limit structure is used to further improve the meshing quality of the worm and the turbine and eliminate abnormal noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of the structure of an electric push rod according to an embodiment of the present invention

[0016] Figure 2 for Figure 1 A structural cross-sectional view of the electric push rod shown;

[0017] Figure 3 for Figure 1 A partial exploded schematic diagram of the electric linear actuator shown;

[0018] Figure 4 for Figure 1Another structural sectional view of the electric push rod shown;

[0019] Figure 5 It is a structural schematic diagram of a push rod mounting seat according to an embodiment of the present invention;

[0020] Figure 6 It is a structural schematic diagram of an upper mounting bracket according to an embodiment of the present invention;

[0021] Figure 7 A schematic diagram of the structure of a turbine 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 DESCRIPTION

[0023] The present invention is further described in detail below with reference to the accompanying drawings.

[0024] like Figures 1 to 8 As shown, the electric push rod of this embodiment includes a screw 1, a turbine 2 and a drive motor 3, and a worm 4 is installed at the output end of the drive motor 3, and the worm 4 is meshed with the turbine 2. The screw 1 is arranged vertically, and the worm 4 is arranged horizontally. Driven by the drive motor 3, the turbine 2 moves up and down along the screw 1. The inner ring of the turbine 2 has an upper extension 21 and a lower extension 22, and the upper extension 21 and the lower extension 22 are mutually connected. An internal thread 24 is formed on the inner circumferential wall of the turbine 2, and an internal thread 24 is formed on the inner circumferential wall of the upper extension 21 and the lower extension 22, which is threadedly connected to the screw 1. The turbine 2 is sleeved on the screw 1 and threadedly connected to the screw 1 through the internal thread 24. That is, the turbine 2 and the nut are designed in an integrated manner, which eliminates the space occupied by the auxiliary connecting parts and the original nut between the traditional transmission mechanism, realizes the size reduction in the movement direction of the mechanism, and realizes the need for installation in a narrow space. In addition, after the nut and the turbine 2 are integrated, they actively rotate with the turbine, and the screw rod 1 serves as a driven part, so that the screw rod 1 does not need to rotate, eliminating the rotational swing, and further eliminating the uneven resistance caused by the sway of the screw rod 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 limited in the push rod mounting seat 6. In this way, the force can be improved, and the turbine 2 can be evenly stressed all around, and the force direction is positive pressure, thereby improving the safety factor of the parts. In addition, the dual-bearing support and limiting structure is adopted to further improve the meshing quality of the worm and the turbine and eliminate abnormal noise.

[0026] In this embodiment, the upper mounting bracket 7 is mounted on the push rod mounting seat 6. Specifically, a screw hole 61 is opened on the mounting wall of the push rod mounting seat 6. There are three mounting walls of the push rod mounting seat 6 and they are distributed in a triangular shape. A screw hole 61 is opened on the top of each mounting wall. A mounting hole 71 corresponding to the screw hole 61 is opened on the mounting wall of the upper mounting bracket 7. A first arc-shaped protrusion 62 is convexly provided on the side of the mounting wall of the push rod mounting seat 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 hole 61 and the mounting hole 71 in sequence to connect and fix the upper mounting bracket 7 to the push rod mounting seat 6. The first arc-shaped protrusion 62 of this embodiment is a cylindrical structure arranged at the edge of the screw hole 61 and extending in a direction away from the screw hole 61. The mounting wall of the push rod mounting seat 6 is convexly provided with a second arc-shaped protrusion 64 on the side facing the fastening screw 8. The second arc-shaped protrusion 64 also adopts a cylindrical structure. A cushion block 9 is provided between the head of the fastening screw 8 and the mounting wall of the push rod mounting seat 6. The cushion block 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 seat 6, the push rod can still be installed vertically even if the mounting surface of the upper mounting bracket 7 is angularly deflected during installation, and the screw can still be fixed perpendicular to the mounting surface without generating bending stress when tightening. When a load is applied from below, no additional stress is generated in the internal parts of the push rod, thereby improving reliability.

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

[0028] A screw rod mounting seat 10 is provided below the push rod mounting seat 6 of the present embodiment. The push rod mounting seat 6 constitutes the upper interface of the electric push rod, and the screw rod mounting seat 10 constitutes the lower interface of the electric push rod. The lower end of the screw rod 1 is mounted on the screw rod mounting seat 10. The screw rod mounting seat 10 includes an outer shell 101 and a force-bearing body 102 limited inside the outer shell 101, and the upper surface of the force-bearing body 102 is a spherical surface. By designing the force-bearing surface as a spherical surface, when the angle of the force-applying surface of the lower interface is skewed, the force-bearing point gradually moves toward the periphery. Compared with the plane force-bearing surface, the force-bearing point will immediately move to the outermost side, thereby improving the stress generated on the force center position and improving safety. In addition, the bottom of the lower base 11 has a bayonet 111, and the outer shell 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 the present invention, terms indicating directions, such as "front", "rear", "up", "down", "left", "right", "side", "top", "bottom", etc., are used to describe various exemplary structural parts and elements of the present invention, but these terms are used here only for the purpose of convenience of description and are determined based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in the present invention can be arranged in different directions, these terms indicating directions are only used as explanations and should not be regarded as limitations. For example, "up" and "down" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

Claims

1. An electric push rod, comprising a screw (1), a turbine (2) and a drive motor (3), wherein a worm (4) is mounted on the output end of the drive motor (3), and the worm (4) is meshed with the turbine (2), characterized in that: An internal thread (24) is formed on the inner circumferential wall of the turbine (2); the turbine (2) is sleeved on the screw rod (1) and is threadedly connected to the screw rod (1) through the internal thread (24); the inner ring of the turbine (2) has an upper extension part (21) and a lower extension part (22); the upper extension part (21) and the lower extension part (22) are interconnected; internal threads (24) threadedly connected to the screw rod (1) are formed on the inner circumferential walls of the upper extension part (21) and the lower extension part (22); a horizontal force-bearing surface (23) is formed on the outer periphery of the lower edge of the upper extension part (21); an upper bearing (51) is installed on the outer periphery of the upper extension part (21); and a lower bearing (52) is installed on the outer periphery of the lower extension part (22); the upper bearing (51) is supported on the horizontal force-bearing surface (23), and the upper bearing (51) and the lower bearing (52) are both limited in 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 seat (6), a screw hole (61) is opened on the mounting wall of the push rod mounting seat (6), a mounting hole (71) corresponding to the screw hole (61) is opened on the mounting wall of the upper mounting bracket (7), a first arc-shaped protrusion (62) is protruded on the side of the mounting wall of the push rod mounting seat (6) facing the upper mounting bracket (7), the mounting wall of the upper mounting bracket (7) abuts against the first arc-shaped protrusion (62), and a fastening screw (8) passes through the screw hole (61) and the mounting hole (71) in sequence to connect and fix the upper mounting bracket (7) to the push rod mounting seat (6).

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

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

5. The electric linear actuator according to claim 2, characterized in that: The push rod mounting seat (6) has three mounting walls which are distributed in a triangular shape, and the top of each mounting wall is provided with the screw hole (61).

6. The electric linear actuator according to claim 1, characterized in that: A second arc-shaped protrusion (64) is convexly provided on the side of the mounting wall of the push rod mounting seat (6) facing the fastening screw (8), and a cushion block (9) is provided between the head of the fastening screw (8) and the mounting wall of the push rod mounting seat (6), and the cushion block (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 screw rod mounting seat (10), which is arranged below the push rod mounting seat (6), and the lower end of the screw rod (1) is mounted on the screw rod mounting seat (10).

8. The electric linear actuator according to claim 7, characterized in that: The screw rod mounting seat (10) comprises 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) is a spherical surface.

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

10. The electric linear actuator according to any one of claims 1 to 9, characterized in that: The screw rod (1) is arranged vertically, and the worm gear (4) is arranged horizontally. Driven by the driving motor (3), the turbine (2) moves up and down along the screw rod (1).

Images