An external magnetic induction waterproof device for electric actuators

Abstract

This utility model belongs to the field of electric linear actuator technology, specifically disclosing an external magnetic induction waterproof device for an electric linear actuator. It includes a lead screw located at the output end of a drive module. An inner tube and an outer tube are sequentially fitted around the lead screw from the inside out. The lead screw is connected to the inner tube via a slide block, on which a magnet is fixedly mounted. A protective cover is sealed along the axial direction of the outer tube, forming an installation cavity. Two magnetic induction switches are installed within the installation cavity, distributed at both ends of the outer tube along its axial direction to sense the position of the magnet. This utility model utilizes the non-contact coupling between the magnet on the slide block and the magnetic induction switches located on the outside of the outer tube, breaking through the spatial limitations of traditional built-in switches. This allows the installation position of the magnetic induction switches to be flexibly adjusted along the axial direction of the outer tube to adapt to different stroke requirements. Simultaneously, the protective cover sealing the outer wall of the outer tube, together with the outer tube, forms an independent installation cavity, improving the waterproof rating and preventing rainwater and dust from directly corroding the magnetic induction switches.

Description

Technical Field

[0001] This utility model belongs to the field of electric linear actuator technology, and in particular relates to an external magnetic induction waterproof device for electric linear actuators. Background Technology

[0002] Electric linear actuators, as mechatronic devices that convert rotary motion into linear motion, are widely used in industrial automation, smart homes, and medical devices. Their core structure typically includes a drive module, a lead screw, a slide, and an outer sheath. The drive module rotates the lead screw, which in turn drives the inner tube connected to the slide to extend or retract axially, achieving linear displacement output. To precisely control the actuator's stroke, current technologies generally employ contact limit switches or built-in magnetic induction switches to detect the slide position.

[0003] Contact-type limit switches: These switches trigger signals through mechanical contacts, which can lead to contact wear and poor contact after long-term use. They also require physical installation space, resulting in an increase in the overall size of the push rod.

[0004] Built-in magnetic induction switch: The Hall sensor or magnetoresistive sensor is integrated inside the inner or outer tube. Although non-contact detection is achieved, it is limited by the small space inside the tube and the sensor installation position is fixed, making it difficult to adapt to different stroke requirements. At the same time, the built-in structure requires openings in the tube wall or adopts a non-sealed design, which leads to a decrease in waterproof and dustproof performance (usually only reaching IP54 level). In humid or dusty environments, it is easy to cause short circuits or sensor failure.

[0005] In addition, the adjustment method of magnetic induction switches in the existing technology generally relies on manual disassembly of the outer shell or tube to adjust the fixed position of the sensor to achieve stroke calibration. The operation is cumbersome and there is a risk of accidental touch. The adjustment efficiency is less than 30%, and frequent disassembly and assembly will damage the sealing structure and further reduce the protection level.

[0006] Therefore, the inventors dedicated themselves to designing a waterproof sensor for an electric actuator to solve the above problems. Utility Model Content

[0007] The purpose of this invention is to provide an external magnetic induction waterproof device for an electric actuator, which overcomes the space limitations of traditional built-in switches. It allows adjustment of the magnetic induction switch to the target position without disassembling the inner and outer tubes of the actuator, thus improving adjustment efficiency and waterproof rating.

[0008] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0009] An external magnetic induction waterproof device for an electric actuator includes a lead screw located at the output end of a drive module. An inner tube and an outer tube are sequentially fitted around the lead screw from the inside out. The lead screw is connected to the inner tube via a slide block, and a magnet is fixedly mounted on the slide block. A protective cover is sealed along the axial direction of the outer tube, forming an installation cavity. Two magnetic induction switches are installed in the installation cavity. The two magnetic induction switches are distributed at both ends of the outer tube along its axial direction to sense the position of the magnet.

[0010] As an improvement to the external magnetic induction waterproof device for the electric push rod of this utility model, the protective cover is made of PVC material and is sealed and snapped together with the outer tube.

[0011] As an improvement of the external magnetic induction waterproof device for the electric push rod of this utility model, two slots are provided at intervals on the outer wall of the outer tube opposite to the protective cover. The mounting cavity is located between the two slots. Two buckles are provided at intervals on the side of the protective cover facing the outer tube. The two buckles and the two slots are sealed and engaged in a one-to-one correspondence.

[0012] As an improvement of the external magnetic induction waterproof device for the electric push rod of this utility model, the slot and the buckle are both arranged along the axial direction of the outer tube, the buckle is hook-shaped and its elastic end is engaged with the corresponding slot inner wall.

[0013] As an improvement of the external magnetic induction waterproof device for electric push rod of this utility model, an installation groove is provided on the outer wall of the outer tube along its axial direction, and the protective cover is placed on the installation groove to form the installation cavity. The two side walls of the installation groove are disconnected to form a break opening, and the break opening is located between the two magnetic induction switches.

[0014] As an improvement of the external magnetic induction waterproof device for electric push rod of this utility model, a sliding groove is provided on the outer wall of the slide block along its axial direction, and a sliding strip is provided on the inner wall of the outer tube along its axial direction, and the sliding strip slides in cooperation with the sliding groove.

[0015] As an improvement of the external magnetic induction waterproof device for electric push rod of this utility model, the slide includes a slider and a nut. The slider is sleeved on the outside of the nut and is slidably connected to the slider through the slide groove. The inner tube is threadedly fixed to the nut. The magnet is fixed on the slider.

[0016] As an improvement of the external magnetic induction waterproof device for the electric push rod of this utility model, a connector is fixedly connected to the top of the protruding end of the inner tube. The connector is located outside the outer tube. A self-aligning ball bearing is provided in the connection hole of the connector, and the gap between the self-aligning ball bearing and the connector is filled with glue.

[0017] As an improvement of the external magnetic induction waterproof device for the electric push rod of this utility model, the self-aligning ball bearing is connected to the joint through injection molding. The glue is arranged in a circle around the middle of the self-aligning ball bearing and the two corresponding ends extend outward to one end face of the joint.

[0018] As an improvement of the external magnetic induction waterproof device for the electric push rod of this utility model, one end of the outer tube and the protective cover are inserted into the housing of the drive module, and the other end of the outer tube and the protective cover are fixed with a fixing seat.

[0019] Compared with existing technologies, the external magnetic induction waterproof device of this utility model electric push rod designs the magnetic induction switch on the outside of the outer tube. It uses a magnet fixed on the slide to non-contactly couple with the magnetic induction switch on the outside of the outer tube, breaking through the spatial limitations of traditional built-in switches. This allows the installation position of the magnetic induction switch to be flexibly adjusted along the axial direction of the outer tube to adapt to different stroke requirements. At the same time, a protective cover is sealed on the outer wall of the outer tube, forming an independent installation cavity with the outer tube, which improves the waterproof level and prevents rainwater and dust from directly corroding the magnetic induction switch. Users do not need to disassemble the inner and outer tubes of the push rod. They only need to open the protective cover and slide the magnetic induction switch in the installation cavity to the target position. The stroke parameters can be calibrated in real time by the change of magnetic induction intensity, improving the adjustment efficiency and avoiding the risk of seal failure caused by disassembling the inner and outer tubes. Attached image description:

[0020] Figure 1 This is an enlarged view of the electric actuator of this utility model;

[0021] Figure 2 This is a three-dimensional enlarged view of the protective cover on the electric push rod of this utility model in the open state;

[0022] Figure 3 yes Figure 2 Enlarged view of point A in the middle;

[0023] Figure 4 This is a partial exploded perspective view of the electric push rod in this utility model;

[0024] Figure 5 This is a three-dimensional enlarged view of the slide of this utility model;

[0025] Figure 6 This is an enlarged cross-sectional view of the electric actuator of this utility model at the slider.

[0026] Figure 7 yes Figure 6 Enlarged view of point B in the middle;

[0027] Figure 8 This is a three-dimensional enlarged exploded view of a portion of the connector and inner tube of this utility model;

[0028] Figure 9 This is a three-dimensional exploded and enlarged view of the connector, glue injection, and self-aligning ball bearing of this utility model;

[0029] Figure 10 This is an enlarged cross-sectional view of the connector of this utility model;

[0030] Figure 11 This is another enlarged cross-sectional view of the connector of this utility model.

[0031] Illustration:

[0032] 1. Inner tube; 2. Outer tube; 21. Mounting slot; 22. Disconnection port; 23. Slot; 231. Slot platform; 24. Sliding bar; 3. Protective cover; 31. Buckle; 4. Magnetic induction switch; 5. Drive module; 51. Lead screw; 6. Nut; 61. Slide block; 62. Retaining ring; 7. Slider; 71. Slide groove; 72. Magnet; 8. Connector; 81. Self-aligning ball bearing; 82. Glue injection; 83. Connecting hole. Detailed Implementation

[0033] The embodiments of this utility model are described in detail below with reference to the accompanying drawings. The drawings are for reference and illustration only and do not constitute a limitation on the scope of patent protection of this utility model.

[0034] Reference Figures 1 to 11 An external magnetic induction waterproof device for an electric actuator includes a lead screw 51 located at the output end of a drive module 5. An inner tube 1 and an outer tube 2 are sequentially fitted around the lead screw 51 from the inside out. The lead screw 51 is connected to the inner tube 1 via a slide block 61. A magnet 72 is fixedly mounted on the slide block 61. A protective cover 3 is sealed along the axial direction of the outer tube 2 to form an installation cavity. Two magnetic induction switches 4 are installed in the installation cavity. The two magnetic induction switches 4 are distributed at both ends of the outer tube 2 along the axial direction to sense the position of the magnet 72.

[0035] Reference Figure 1 , Figure 2 and Figure 4 The drive module 5 includes a housing, a worm gear, a worm, and a motor. The worm gear, worm, and motor are all located inside the housing. The worm is located on the output shaft of the motor. The worm gear meshes with the worm and is sleeved on the bottom end of the lead screw 51. The motor inside the housing drives the worm to rotate, the worm drives the worm gear to rotate, and the worm gear drives the lead screw 51 to rotate. Therefore, the lead screw 51 is located at the output end of the drive module 5.

[0036] Reference Figure 4 , Figure 5 , Figure 6 and Figure 7The inner tube 1 and the slide block 61 are sequentially sleeved on the lead screw 51 from top to bottom. Both the slide block 61 and the inner tube 1 are located inside the outer tube 2. The slide block 61 is slidably connected to the outer tube 2. A groove 71 is provided on the outer wall of the slide block 61 along its axial direction. A slide bar 24 is provided on the inner wall of the outer tube 2 along its axial direction. The slide bar 24 is slidably engaged with the groove 71. Specifically, the slide block 61 includes a slider 7 and a nut 6. The nut 6 is preferably a ball nut. The nut 6 is sleeved on the lead screw 51 and threadedly connected to the lead screw 51. The upper end of the nut 6 is inserted into the outer tube 2 and threadedly fixedly connected to the outer tube 2. The lower outer wall of the nut 6 is polygonal, the slider 7 is annular and sleeved on the lower end of the nut 6, the inner wall of the slider 7 is also polygonal and fits with the lower end of the nut 6 to prevent the slider 7 from rotating relative to the nut 6. The lower end of the nut 6 is fitted with an annular retaining ring 62, and the slider 7 is located on the retaining ring 62. The sliding groove 71 is set on the outer wall of the slider 7 along the axial direction of the slider 7. There are two sliding grooves 71 and they are respectively set on the slider 7. The slider 7 is slidably connected to the sliding strip 24 on the inner wall of the outer tube 2 through the sliding groove 71. The magnet 72 is fixed in the outer groove of the slider 7.

[0037] Reference Figure 2 , Figure 4 , Figure 8 , Figure 9 , Figure 10 and Figure 11 A connector 8 is fixedly connected to the top of the inner tube 1. The entire connector 8 is located outside the outer tube 2. The lower end of the connector 8 is inserted into the top of the inner tube 1 and is threadedly fixed to the inner wall of the inner tube 1. The upper end of the connector 8 is located outside the inner tube 1 and is provided with a connecting hole 83 to form a ring. A self-aligning ball bearing 81 is provided in the connecting hole 83 of the connector 8. The gap between the self-aligning ball bearing 81 and the connector 8 is filled with injection adhesive 82. The self-aligning ball bearing 81 is connected to the connector 8 through injection molding. The injection adhesive 82 is arranged in a circle around the middle of the self-aligning ball bearing 81 and the two corresponding ends extend outward to one end face of the connector 8. The injection adhesive 82 is made of polymer material, which not only ensures the axial pressure of the self-aligning ball bearing 81, but also reduces the gap of the self-aligning ball bearing 81.

[0038] Reference Figure 1 , Figure 2 , Figure 3 , Figure 6 and Figure 7The lower ends of the outer tube 2 and the protective cover 3 are inserted into the housing of the drive module 5. A fixing seat is fixed on the upper end face of the outer tube 2 and the protective cover 3. The protective cover 3 is made of PVC material and is sealed and snapped into the outer tube 2. An installation groove 21 is provided on the outer wall of the outer tube 2 along its axial direction. The protective cover 3 is placed on the installation groove 21 to form an installation cavity. The two side walls of the installation groove 21 are disconnected to form a break opening 22. The break opening 22 is located between the two magnetic induction switches 4. Two slots 23 are provided at intervals on the outer wall of the outer tube 2 opposite to the protective cover 3. The installation cavity is located between the two slots 23. Two buckles 31 are provided at intervals on the side of the protective cover 3 facing the outer tube 2. The slots 23 and buckles 31 are both arranged along the axial direction of the outer tube 2. Each buckle 31 is hook-shaped and its elastic end is engaged with the corresponding slot 231 on the inner wall of the slot 23 so that the two buckles 31 are sealed and snapped into the two slots 23 one by one to prevent external water from entering the installation cavity and damaging the magnetic induction switches 4.

[0039] Reference Figures 1 to 11 The working principle of the external magnetic induction waterproof device for electric push rod of this utility model is as follows:

[0040] The output end of the drive module 5 drives the lead screw 51 to rotate. The lead screw 51 drives the nut 6 and the slider 7 to slide together in the outer tube 2 along its axis, thereby causing the upper end of the inner tube 1 to extend to the outside of the outer tube 2. The two magnetic induction switches 4 detect the position change of the magnet 72 on the slider 7, and thus detect the extension length of the inner tube 1. When it is necessary to adjust the position of the two magnetic induction switches 4, the protective cover 3 can be removed directly to adjust the position of the two magnetic induction switches 4 on the outer tube 2.

[0041] This utility model discloses an external magnetic induction waterproof device for an electric actuator. It employs an external switch layout, utilizing magnetic induction to achieve non-contact stroke adjustment and installation distance adaptation. The external switch is a waterproof magnetic switch, with a screw-locking structure enabling quick disassembly and fine-tuning of the position. The switch is covered by an inverted PVC protective cover 3, forming a double waterproof barrier. This utility model overcomes the installation space limitations of traditional built-in switches, utilizing magnetic induction to achieve "adjustment without disassembly." Combined with the inverted PVC protective cover 3 design, it improves the waterproof rating (IPX7 and above) while increasing adjustment efficiency by more than 50%.

[0042] Compared with the prior art, the external magnetic induction waterproof device for electric actuators of this utility model has the following beneficial technical effects:

[0043] External magnetic induction layout: The magnetic induction switch 4 is designed outside the outer tube 2. The magnet 72 fixed on the slide 61 is non-contactly coupled to the magnetic induction switch 4 on the outside of the outer tube 2, breaking through the spatial limitations of traditional built-in switches. This allows the installation position of the magnetic induction switch 4 to be flexibly adjusted along the axis of the outer tube 2 to adapt to different travel requirements. The external switch is a waterproof magnetic switch, and a screw locking structure enables quick disassembly, assembly, and fine-tuning of its position. The switch is covered by an inverted PVC protective cover 3, forming a double waterproof barrier. While improving the waterproof rating (IPX7 and above), the adjustment efficiency is increased by more than 50%.

[0044] Waterproof barrier 3: The protective cover 3 is sealed on the outer wall of the outer tube 2, forming an independent installation cavity together with the outer tube 2. This not only prevents rainwater and dust from directly corroding the sensor, but also improves the waterproof rating to IP67.

[0045] No disassembly required adjustment mechanism: Users do not need to disassemble the push rod housing. They only need to slide the magnetic induction switch 4 in the installation cavity to the target position. The stroke parameters can be calibrated in real time by the change in magnetic induction intensity. The adjustment efficiency is more than 50% higher than that of traditional solutions, while avoiding the risk of seal failure caused by disassembly.

[0046] The above-disclosed embodiments are merely preferred embodiments of the present utility model and should not be construed as limiting the scope of protection of the present utility model. Therefore, any equivalent changes made in accordance with the scope of the patent application of the present utility model shall still fall within the scope of the present utility model.

Claims

1. An external magnetic induction waterproof device of an electric push rod, comprising a lead screw arranged at an output end of a driving module, an inner tube and an outer tube are sequentially sleeved outside the lead screw from inside to outside, the lead screw is connected with the inner tube through a sliding seat, characterized in that, A magnet is fixedly installed on the slide block. A protective cover is sealed along the axial direction of the outer wall of the outer tube to form an installation cavity. Two magnetic induction switches are installed in the installation cavity. The two magnetic induction switches are distributed at both ends of the outer tube along its axial direction to sense the position of the magnet.

2. The external magnetic induction waterproof device for an electric trolley according to claim 1, characterized in that, The protective cover is made of PVC material and is sealed and snapped together with the outer tube.

3. The external magnetic induction waterproof device for an electric trolley according to claim 2, characterized in that, The outer wall of the outer tube is provided with two slots at intervals opposite to the protective cover. The mounting cavity is located between the two slots. The protective cover is provided with two buckles at intervals on the side facing the outer tube. The two buckles and the two slots are sealed and engaged in a one-to-one correspondence.

4. The external magnetic induction waterproof device for an electric trolley according to claim 3, characterized in that, Both the slot and the buckle are arranged along the axial direction of the outer tube. The buckle is hook-shaped and its elastic end engages with the corresponding slot inner wall.

5. The external magnetic induction waterproof device for an electric trolley according to claim 1, characterized in that, An installation groove is provided on the outer wall of the outer tube along its axial direction. The protective cover is placed on the installation groove to form the installation cavity. The two side walls of the installation groove are disconnected to form a break opening. The break opening is located between the two magnetic induction switches.

6. The external magnetic induction waterproof device for an electric trolley according to claim 1, characterized in that, The outer wall of the slide block is provided with a sliding groove along its axial direction, and the inner wall of the outer tube is provided with a sliding strip along its axial direction, the sliding strip slidingly engaging with the sliding groove.

7. The external magnetic induction waterproof device for an electric trolley according to claim 6, characterized in that The slide block includes a slider and a nut. The slider is sleeved on the outside of the nut and slidably connected to the slider strip through the slide groove. The inner tube is threadedly fixed to the nut. The magnet is fixed to the slider.

8. The external magnetic induction waterproof device for an electric trolley according to claim 1, characterized in that, A connector is fixedly connected to the top of the protruding end of the inner tube. The connector is located outside the outer tube. A self-aligning ball bearing is provided in the connection hole of the connector. The gap between the self-aligning ball bearing and the connector is filled with glue.

9. The external magnetic induction waterproof device for an electric trolley according to claim 8, characterized in that, The self-aligning ball bearing is connected to the joint via injection molding. The injection molding compound surrounds the center of the self-aligning ball bearing in a ring, with its two corresponding ends extending outward to one end face of the joint.

10. The external magnetic induction waterproof device for an electric trolley according to claim 1, characterized in that, One end of the outer tube and the protective cover is inserted into the housing of the drive module, and the other end of the outer tube and the protective cover is fixed with a mounting base.

Images