Linear electric push rod directly driven by motor

Abstract

The utility model provides a linear electric push rod directly driven by a motor, which comprises a shell, a motor, a screw rod and a telescopic rod, the motor, the screw rod and the telescopic rod are coaxially arranged, and the output shaft of the motor and the near end of the screw rod are circumferentially fixed and axially limited through a rotation constraint structure; the near end of the telescopic rod is provided with an internal threaded hole, the internal threaded hole and external threads of the lead screw form a lead screw pair, the far end of the telescopic rod extends out of the shell and is provided with a second connecting piece, and when the motor directly drives the lead screw to rotate, the lead screw pair converts rotary motion into axial linear motion of the telescopic rod. The telescopic rod and a guide sliding groove in the inner wall of the shell form a sliding pair through an annular flange, and a limiting flange is further arranged at the far end to restrain radial displacement. The linear type electric push rod directly driven by the motor is compact in overall design structure and high in transmission efficiency, achieves high-precision linear motion through combination of direct drive and a lead screw pair, is suitable for connection of executing mechanisms needing stable push-pull force, and is wide in application scene.

Description

Technical Field

[0001] This utility model relates to the field of electric linear actuator technology, and in particular to a direct-drive linear electric linear actuator. Background Technology

[0002] An electric linear actuator (also known as an electric cylinder or electric actuator) is a mechatronic device that converts the rotary motion of an electric motor into linear reciprocating motion. Due to its compact structure, precise control, and ease of automation, electric linear actuators are widely used in industrial automation, medical devices, smart home appliances, automobiles, aerospace, and many other fields to achieve functions such as lifting, pushing, pulling, positioning, and clamping of objects.

[0003] Traditional linear electric linear actuators typically consist of a motor, a transmission mechanism (such as a belt, gear, or worm gear reducer), and the actuator body. These components often need to be arranged in series, resulting in a relatively long axial dimension of the entire actuator and a less compact structure, making it difficult to meet the needs of applications with strict space constraints. In addition, traditional transmission methods may suffer from efficiency losses, noise, wear, and the need for regular maintenance.

[0004] In existing technologies, couplings, keyed connections, or splined connections are commonly used to transmit torque from the motor to the lead screw. While these connection methods are reliable, they inevitably increase the overall axial length of the push rod. Furthermore, to ensure the push rod does not rotate circumferentially during operation, a specialized guide and anti-rotation structure, such as a sliding key, guide key, or additional linear bearing, is required between the push rod body and the housing. These structures not only increase the number and complexity of parts but may also introduce additional frictional resistance, affecting the push rod's operating efficiency and lifespan. Therefore, more compact, high-efficiency, stable, reliable, and easy-to-install and maintain direct-drive linear electric push rods require solutions that significantly reduce axial dimensions, optimize internal transmission and connection structures, simplify guide and anti-rotation design, and improve overall rigidity and load-bearing capacity to meet the increasingly demanding space utilization and performance requirements of modern equipment. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a direct-drive linear electric actuator, which features a compact structure, stable transmission, and easy installation, thus solving core issues such as connection reliability, motion guidance, and end support.

[0006] To solve the above-mentioned technical problems, this utility model proposes a motor-driven linear electric actuator, including a housing, and a motor, a lead screw, and a telescopic rod coaxially disposed within the housing. The output shaft of the motor is fixedly connected to the proximal end of the lead screw, and the proximal end of the telescopic rod is provided with an internal threaded hole. The external thread of the lead screw and the internal threaded hole of the telescopic rod form a lead screw pair. The distal end of the telescopic rod extends to the outside of the housing. When the motor drives the lead screw to rotate, the rotational motion is converted into axial linear motion of the telescopic rod relative to the housing through the lead screw pair.

[0007] As a further limitation of this utility model, a first connecting member is fixedly provided at the end of the housing near the motor, and a second connecting member is provided at the far end of the telescopic rod. The first connecting member and the second connecting member are used to connect the external fixed base and the actuator, respectively.

[0008] As a further limitation of this utility model, the output shaft of the motor is provided with an axially extending flat structure at its end, and a radial through hole is provided at the near end of the lead screw. The pin passes through the radial through hole and abuts against the plane of the flat structure. The pin, the flat structure and the radial through hole constitute a rotation constraint structure, so that the lead screw and the output shaft rotate synchronously and are axially fixed.

[0009] As a further limitation of this utility model, the near end of the telescopic rod is provided with a radially outwardly extending annular flange, and the inner wall of the housing is provided with an axially extending guide groove. The annular flange is embedded in the guide groove and forms a sliding pair.

[0010] As a further limitation of this utility model, the outer inner wall of the housing is provided with a radially inwardly extending limiting flange, and the central through hole of the limiting flange and the outer peripheral wall of the telescopic rod form a clearance fit.

[0011] As a further limitation of this utility model, the first connector includes an end cap, the inner wall of the near end of the housing is provided with a snap-fit ​​portion, and the outer periphery of the end cap is provided with a snap-fit ​​groove, the snap-fit ​​groove and the snap-fit ​​portion forming a snap-fit ​​connection.

[0012] The beneficial effects of this utility model are:

[0013] This technical solution, through its coaxial direct drive layout, compact and efficient shaft connection method, integrated guide and anti-rotation structure, and quick-installation connection design, features a compact structure, high transmission efficiency, smooth operation, reliability, and ease of installation and maintenance. It effectively overcomes many shortcomings of traditional electric linear actuators, and therefore has a wide range of applications. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a cross-sectional schematic diagram of a direct-drive linear electric actuator according to an embodiment of the present invention;

[0016] Figure 2 This is an exploded structural diagram of a direct-drive linear electric actuator according to an embodiment of the present invention;

[0017] Figure 3 This is a schematic diagram of the overall structure of the direct-drive linear electric actuator according to an embodiment of the present invention.

[0018] Reference numerals: housing 1; guide groove 11; limiting flange 12; snap-fit ​​part 13; motor 2; flat structure 21; lead screw 3; radial through hole 31; telescopic rod 4; annular flange 41; first connector 5; end cap 51; slot 52; second connector 6. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] Please see Figure 1 , Figure 2 and Figure 3 The direct-drive linear electric actuator provided in this embodiment includes a housing 1, and a motor 2, a lead screw 3, and a telescopic rod 4 coaxially disposed within the housing 1. The motor 2 can be a coreless motor. The output shaft of the motor 2 is fixedly connected to the proximal end of the lead screw 3. Preferably, the output shaft of the motor 2 is fixedly connected to the proximal end of the lead screw 3 through a reduction gearbox. The proximal end of the telescopic rod 4 is provided with an internal threaded hole. The external thread of the lead screw 3 and the internal threaded hole of the telescopic rod 4 form a lead screw pair. The distal end of the telescopic rod 4 extends to the outside of the housing 1. When the motor 2 drives the lead screw 3 to rotate, the rotational motion of the lead screw 3 is converted into the axial linear motion of the telescopic rod 4 relative to the housing 1 through the lead screw pair.

[0021] A first connector 5 is fixedly installed at one end of the housing 1 near the motor 2, and a second connector 6 is provided at the far end of the telescopic rod 4. The first connector 5 and the second connector 6 are used to connect the external fixed base and the actuator, respectively.

[0022] like Figure 1 As shown, the output shaft of motor 2 is provided with an axially extending flat structure 21 at its end. The flat structure 21 can also be called an anti-rotation plane. A radial through hole 31 is provided at the near end of the lead screw 3. The pin passes through the radial through hole 31 and abuts against the plane of the flat structure 21. The pin, the flat structure 21 and the radial through hole 31 constitute a rotation constraint structure, so that the lead screw 3 and the output shaft of motor 2 rotate synchronously and are axially fixed.

[0023] like Figure 1 and Figure 2 As shown, the near end of the telescopic rod 4 is provided with a radially outwardly extending annular flange 41, and the inner wall of the housing 1 is provided with an axially extending guide groove 11. The annular flange 41 is embedded in the guide groove 11 and forms a sliding pair. The inner wall of the far end of the housing 1 is provided with a radially inwardly extending limiting flange 12. The central through hole of the limiting flange 12 and the outer peripheral wall of the telescopic rod 4 form a clearance fit. The far end of the telescopic rod 4 can extend out of the housing 1.

[0024] like Figure 1 and Figure 2 As shown, the first connector 5 includes an end cap 51, a snap-fit ​​portion 13 is provided on the inner wall near the end of the housing 1, and a snap-fit ​​groove 52 is provided on the outer periphery of the end cap 51. The snap-fit ​​groove 52 and the snap-fit ​​portion 13 form a snap-fit ​​connection.

[0025] The working principle of this direct-drive linear electric actuator in this embodiment is as follows: When the motor starts and the motor output shaft rotates, the torque is transmitted to the near end of the lead screw through the constraint structure (pin, flat structure, and radial through hole). The rotation of the lead screw drives the lead screw pair formed by its external thread and the internal thread hole at the near end of the telescopic rod, converting the rotational motion into the axial linear motion of the telescopic rod. The annular flange at the near end of the telescopic rod is embedded in the axial guide groove inside the housing, forming a sliding pair. When the telescopic rod extends out of the housing, its outer wall forms a clearance fit with the center through hole of the limiting flange at the far end of the housing, radially constraining the runout and preventing the lead screw pair from jamming. The near end of the housing is connected to the external base through the first connecting piece, and the second connecting piece at the far end of the telescopic rod is connected to the actuator, outputting push / pull force.

[0026] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A motor-driven linear electric actuator, characterized in that, The device includes a housing (1), and a motor (2), a lead screw (3), and a telescopic rod (4) coaxially disposed within the housing (1). The output shaft of the motor (2) is fixedly connected to the proximal end of the lead screw (3). The proximal end of the telescopic rod (4) is provided with an internal threaded hole. The external thread of the lead screw (3) and the internal threaded hole of the telescopic rod (4) form a lead screw pair. The distal end of the telescopic rod (4) extends to the outside of the housing (1). When the motor (2) drives the lead screw (3) to rotate, the rotational motion is converted into the axial linear motion of the telescopic rod (4) relative to the housing (1) through the lead screw pair.

2. The direct-drive linear electric actuator according to claim 1, characterized in that, The housing (1) is fixedly provided with a first connector (5) at one end near the motor (2), and the telescopic rod (4) is provided with a second connector (6) at the far end. The first connector (5) and the second connector (6) are used to connect the external fixed base and the actuator respectively.

3. The direct-drive linear electric actuator according to claim 1, characterized in that, The output shaft of the motor (2) has an axially extending flat structure (21) at its end, and a radial through hole (31) is provided at the near end of the lead screw (3). The pin passes through the radial through hole (31) and abuts against the plane of the flat structure (21). The pin, the flat structure (21) and the radial through hole (31) constitute a rotation constraint structure, so that the lead screw (3) rotates synchronously with the output shaft and is axially fixed.

4. The direct-drive linear electric actuator according to claim 1, characterized in that, The telescopic rod (4) has a radially outwardly extending annular flange (41) at its near end, and the inner wall of the housing (1) has an axially extending guide groove (11). The annular flange (41) is embedded in the guide groove (11) and forms a sliding pair.

5. The direct-drive linear electric actuator according to claim 4, characterized in that, The outermost inner wall of the housing (1) is provided with a radially inwardly extending limiting flange (12), and the central through hole of the limiting flange (12) and the outer peripheral wall of the telescopic rod (4) form a clearance fit.

6. The direct-drive linear electric actuator according to claim 2, characterized in that, The first connector (5) includes an end cap (51), and the inner wall of the near end of the housing (1) is provided with a snap-fit ​​part (13). The outer periphery of the end cap (51) is provided with a snap-fit ​​groove (52), and the snap-fit ​​groove (52) and the snap-fit ​​part (13) form a snap-fit ​​connection.

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