Pen type electric push-pull rod

Abstract

The utility model discloses a pen type electric push-pull rod, and belongs to the technical field of electric push rods. The electric push rod comprises a shell assembly, a power driving combination, a transmission assembly and a limit switch assembly, wherein the shell assembly is provided with a sealed cavity; the power driving assembly comprises a DC motor and a fixed star gear box coaxially connected with the DC motor, the DC motor and the fixed star gear box are sequentially installed in the sealed cavity, and a motor connecting flange is installed at the output end of the fixed star gear box; the transmission assembly comprises a screw and a sliding nut in threaded fit with the screw, and one end of the screw is connected with the output end of the fixed star gearbox. The limit switch assembly comprises a switch circuit board, a switch triggering piece and a switch positioning piece which are distributed along the axial direction of the screw rod, and is integrated above the motor connecting flange through a switch fixing disc; when the sliding nut moves linearly along the screw, the switch triggering piece can be triggered to achieve stroke limiting and direction control of the push-pull rod. The pen type electric push-pull rod is compact in structure, high in sealing performance, accurate in control and long in service life.

Description

Technical Field

[0001] This utility model belongs to the technical field of electric linear actuators, specifically relating to a pen-type electric push-pull actuator. Background Technology

[0002] Electric push-pull rods, as a common linear motion actuator, are widely used in medical equipment, automated instruments, smart homes, and other fields. Traditional electric push-pull rods generally suffer from loose structures and excessively large axial dimensions, making it difficult to meet the miniaturization and high integration requirements of precision equipment. For example, existing electric push rods typically rely on external sensors for limit control, resulting in complex structures and high costs; furthermore, open transmission mechanisms are susceptible to dust or liquid intrusion, affecting long-term reliability.

[0003] Especially for applications requiring high precision and small size, existing electric linear actuators struggle to meet the demands for compactness, sealing, and intelligent control. While some products attempt to simplify the structure by integrating limit switches, they still suffer from drawbacks such as low trigger sensitivity, easy wear, and insufficient waterproof and dustproof performance. Therefore, there is an urgent need for an electric linear actuator that is compact, highly sealed, precisely controlled, and has a long lifespan. Utility Model Content

[0004] The purpose of this invention is to provide a pen-type electric push-pull rod that is compact in structure, has strong sealing performance, precise control, and long service life.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A pen-type electric push-pull rod, characterized in that it comprises:

[0007] Housing assembly, the housing assembly having a sealed cavity;

[0008] A power drive assembly, comprising a DC motor and a stellar gearbox coaxially connected thereto, wherein the DC motor and the stellar gearbox are sequentially installed in a sealed cavity, and a motor connection flange is installed at the output end of the stellar gearbox;

[0009] A transmission assembly, comprising a screw and a sliding nut threadedly engaged therewith, one end of the screw being connected to the output end of a star gearbox, and the sliding nut being capable of linear movement along the screw axis;

[0010] The limit switch assembly includes a switch circuit board, a switch trigger, and a switch positioning element distributed along the screw axis, and is integrated above the motor connection flange via a switch fixing plate; when the sliding nut moves linearly along the screw, it can trigger the switch trigger to realize the stroke limit and direction control of the push-pull rod.

[0011] Preferably, the switch trigger includes an upper switch trigger and a lower switch trigger connected to both ends of the switch connector; the switch positioning includes an upper switch positioning and a lower switch positioning respectively disposed on both sides of the switch circuit board.

[0012] Preferably, the lower switch trigger is located in a groove on one side of the lower switch positioning member, and the switch connector passes through the edge of the switch circuit board, the upper switch positioning member, and the sliding nut; a spring is sleeved on the switch connector to abut against the lower switch trigger and the switch circuit board.

[0013] Preferably, the motor connection flange has a bearing inside, which is sleeved on the end of the screw to provide radial support.

[0014] Preferably, a stabilizing element is fitted onto the top of the screw, and a retaining spring is provided between the upper end of the stabilizing element and the screw.

[0015] Preferably, the housing assembly includes an upper housing, a lower housing, and a lower cover. The upper housing and the lower housing are threadedly connected, and the lower housing, the lower cover, and the motor connection flange form a sealed cavity.

[0016] Preferably, the upper housing is provided with a push rod, the end of which is fixed to a sliding nut.

[0017] Preferably, an oil seal is provided between the top of the upper housing and the push rod.

[0018] Preferably, the switch circuit board includes a diode rectifier return current protection circuit for automatically cutting off power when the electric push-pull rod reaches its effective stroke.

[0019] Preferably, the DC motor is equipped with an encoder at its tail end, which is used to transmit pulse signals to the controller based on the speed of the DC motor.

[0020] The beneficial effects of this utility model are:

[0021] (1) High integration and miniaturization design: Through the sealed cavity design of the housing component, the power drive component, transmission component and limit switch component are integrated into one, the overall structure is compact, in the shape of a pen cylinder, which significantly reduces the volume and is suitable for medical equipment, precision instruments and other scenarios with demanding space requirements.

[0022] (2) High-precision stroke control and intelligent limit: The limit switch assembly achieves fast response and automatic power-off function through the coordinated action of the upper and lower switch triggers and the switch circuit board, combined with the diode rectification return protection circuit; when the sliding nut moves to the stroke limit, the trigger accurately contacts the switch circuit board to ensure the repeatability and reliability of the push rod action.

[0023] (3) Strong sealing and environmental adaptability: The housing assembly adopts a threaded connection of upper housing, lower housing and lower cover, combined with the oil seal between the push rod and the upper housing to form a multi-layer sealing structure, which effectively prevents dust and liquid intrusion and is suitable for harsh environments such as humid and dusty environments.

[0024] (4) Intelligent feedback and closed-loop control: The DC motor integrates an encoder at the tail end to detect the speed pulse signal in real time and feed it back to the external controller, supporting the synchronous action of multiple push and pull rods or precise positioning. Attached Figure Description

[0025] For ease of explanation, this utility model is described in detail below with reference to the specific embodiments and accompanying drawings.

[0026] Figure 1 This is a schematic diagram of the overall external structure of this embodiment;

[0027] Figure 2 This is an example. Figure 1 Sectional view at point AA;

[0028] Figure 3 This is a schematic diagram of the internal structural layout of this embodiment;

[0029] Figure 4 This is a schematic diagram showing the internal structure of this embodiment.

[0030] In the picture:

[0031] 100-Housing assembly; 110-Upper housing; 120-Lower housing; 130-Lower cover; 140-Push rod; 150-Oil seal; 200-Power drive assembly; 210-DC motor; 220-Stellar gearbox; 230-Motor connecting flange; 240-Bearing; 300-Transmission assembly; 310-Screw; 320-Sliding nut; 330-Stabilizing component; 400-Limit switch assembly; 410-Switch circuit board; 420-Switch mounting plate; 430-Upper switch trigger; 440-Lower switch trigger; 450-Upper switch positioning component; 460-Lower switch positioning component; 470-Switch connector; 480-Spring. Detailed Implementation

[0032] The following are specific embodiments of the present invention described in conjunction with the accompanying drawings, further illustrating the technical solution of the present invention. However, the present invention is not limited to these embodiments. Specific details such as particular configurations and components are provided in the following description merely to aid in a comprehensive understanding of the embodiments of the present invention. Therefore, those skilled in the art should understand that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention. Furthermore, for clarity and brevity, descriptions of known functions and structures have been omitted.

[0033] It should be noted that, where there is no conflict, the embodiments and features in the embodiments of this utility model can be combined with each other.

[0034] like Figure 1-4 As shown, this embodiment provides a pen-type electric push-pull rod, including a housing assembly 100, a power drive assembly 200, a transmission assembly 300, and a limit switch assembly 400. The housing assembly 100 consists of an upper housing 110, a lower housing 120, and a lower cover 130, which are connected by threads to form a sealed cavity. A push rod 140 is provided inside the upper housing 110, and the end of the push rod is fixedly connected to the sliding nut 320 of the transmission assembly 300. An oil seal 150 is provided between the top of the push rod and the upper housing 110 to achieve dynamic sealing.

[0035] The power drive assembly 200 includes a DC motor 210 and a star gearbox 220 coaxially connected thereto. The DC motor 210 and the star gearbox 220 are installed in a sealed cavity. The output end of the star gearbox 220 is fixedly connected to the screw 310 of the transmission assembly 300 through a motor connection flange 230. A bearing 240 is sleeved at the end of the screw 310 to provide radial support and reduce friction. The transmission assembly 300 converts the rotational motion of the motor into the linear motion of the push rod 140 through a sliding nut 320 threadedly engaging with the screw 310.

[0036] The limit switch assembly 400 is integrated above the motor connection flange 230 and includes a switch circuit board 410, a switch fixing plate 420, an upper switch trigger 430, a lower switch trigger 440, and a spring 480. The switch connector 470 passes through the edge of the switch circuit board 410, the upper switch positioning member 450, and the sliding nut 320, and its two ends are respectively connected to the upper switch trigger 430 and the lower switch trigger 440. When the sliding nut 320 moves along the screw 310 to the limit position of the stroke, it makes pressure contact with the upper switch trigger 430 or the lower switch trigger 440 and connects to the switch circuit board 410 to achieve precise stroke limit and direction control. In addition, the switch circuit board 410 is equipped with a diode rectification backflow protection circuit, which can automatically cut off the power when the electric push-pull rod runs within the effective stroke, thereby enhancing the service life of the product.

[0037] In this embodiment, an oil seal 150 is provided between the upper housing 110 and the push rod 140 to prevent external contaminants from entering. The lower cover 130 is threadedly connected to the lower housing 120, further enhancing the dustproof and waterproof performance of the sealed cavity. A stabilizing member 330 is fitted onto the top of the screw 310 and fixed by a snap ring to suppress the radial displacement of the sliding nut 320 and ensure smooth movement.

[0038] In this embodiment, an encoder is installed at the tail of the DC motor 210. As the DC motor 210 rotates, the magnetic ring on its shaft rotates synchronously. A dual-channel Hall sensor is installed on the circuit to provide feedback AB pulse signals. The encoder's function is to detect how many pulses are generated per revolution of the motor. The pulse signals detected by the DC motor's speed are transmitted to the controller. When the controller detects the pulse signals, it can control the push rods accordingly. This embodiment of the pen-type electric push rod can control multiple push rods to achieve real-time synchronous operation or synchronous stopping through signal pulse signals, enhancing product performance, ensuring safety and reliability, and broad applicability, making it suitable for various industries.

[0039] Working principle: After the DC motor 210 is powered on, it drives the stellar gearbox 220 to output low-speed, high-torque power, which drives the screw 310 to rotate. The sliding nut 320 moves linearly along the axial direction under the thread drive of the screw, pushing the push rod 140 to extend or retract. When the sliding nut 320 moves to the preset end point of the stroke, it triggers the lower switch trigger 440 or the upper switch trigger 430, connecting the switch circuit board 410. At the same time, the encoder detects the speed pulse signal of the DC motor 210 in real time and feeds it back to the external controller to achieve closed-loop control, further improving motion accuracy.

[0040] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0041] In the description of this application, it should be understood that the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0042] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

Claims

1. A pen-type electrically powered push-pull rod characterized by comprising: The application relates to a power-driven push-pull rod, which comprises the following components: a shell assembly (100) provided with a sealed cavity; a power-driven assembly (200) comprising a DC motor (210) and a sun gear box (220) coaxially connected with the DC motor (210), wherein the DC motor (210) and the sun gear box (220) are sequentially arranged in the sealed cavity, and a motor connecting flange (230) is arranged at the output end of the sun gear box (220); a transmission assembly (300) comprising a screw rod (310) and a sliding nut (320) threadedly matched with the screw rod (310), wherein one end of the screw rod (310) is connected with the output end of the sun gear box (220), and the sliding nut (320) can move linearly along the screw rod (310) in the axial direction; a limit switch assembly (400) comprising a switch circuit board (410), a switch triggering piece and a switch positioning piece which are arranged in the axial direction of the screw rod (310) and integrated above the motor connecting flange (230) through a switch fixing disc (420); when the sliding nut (320) moves linearly along the screw rod (310), the switch triggering piece can be triggered to realize stroke limiting and direction control of the power-driven push-pull rod.

2. A pen-type electrically powered push-pull rod according to claim 1, wherein The switch triggering piece comprises an upper switch triggering piece (430) and a lower switch triggering piece (440) which are connected at the two end portions of a switch connecting piece (470); the switch positioning piece comprises an upper switch positioning piece (450) and a lower switch positioning piece (460) which are separately arranged at the two sides of the switch circuit board (410).

3. A pen style electric push-pull rod according to claim 2, wherein The lower switch triggering piece (440) is arranged in a groove at one side of the lower switch positioning piece (460), the switch connecting piece (470) penetrates through the edges of the switch circuit board (410), the upper switch positioning piece (450) and the sliding nut (320), and a spring (480) is arranged on the switch connecting piece (470) and abuts between the lower switch triggering piece (440) and the switch circuit board (410).

4. A pen-type electrically powered push-pull rod according to claim 1, wherein A bearing (240) is arranged in the motor connecting flange (230) and sleeved with the end of the screw rod (310) to provide radial support.

5. A pen-type electrically powered push-pull rod according to claim 1, wherein A stabilizing piece (330) is sleeved with the top end of the screw rod (310), and a clamping spring is arranged between the upper end of the stabilizing piece (330) and the screw rod (310).

6. A pen style electrically powered push-pull rod as defined in claim 1, wherein The shell assembly (100) comprises an upper shell (110), a lower shell (120) and a lower cover (130), the upper shell (110) is threadedly connected with the lower shell (120), and the lower shell (120), the lower cover (130) and the motor connecting flange (230) form the sealed cavity.

7. A pen style electric push-pull rod according to claim 6, wherein A push rod (140) is arranged in the upper shell (110) and fixed with the sliding nut (320) at the end.

8. A pen style electric push-pull rod according to claim 7, wherein An oil seal (150) is arranged between the top end of the upper shell (110) and the push rod (140).

9. A pen-type electrically powered push-pull rod according to claim 1, wherein The switch circuit board (410) comprises a diode rectification backflow protection circuit for automatically cutting off power supply when the power-driven push-pull rod operates to the effective stroke.

10. A pen-type electrically powered push-pull rod according to claim 1, wherein The DC motor (210) tail is provided with an encoder, which is used for transmitting a speed detection pulse signal to a controller through the DC motor (210).

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