Multi-layer composite waterproof structure of electric push rod pushing end

Abstract

This utility model belongs to the field of electric linear actuator technology, specifically disclosing a multi-layer composite waterproof structure for the pushing end of an electric linear actuator. It includes an inner tube and an outer tube sleeved outside the inner tube. The inner tube is driven by a lead screw at the output end of a drive module to extend and retract axially along the outer tube. A fixed seat is fixedly connected to the top end face of the outer tube. The retractable end of the inner tube passes through the fixed seat and extends beyond it. A lower waterproof groove and an upper waterproof groove are sequentially provided on the inner wall of the fixed seat along the extension direction of the inner tube. A lip seal is installed in the upper waterproof groove, and a Y-shaped oil seal is installed in the lower waterproof groove. The fixed seat forms a dynamic sealing connection with the inner tube through the lip seal and the Y-shaped oil seal. The dynamic contact surfaces of the lip seal and the Y-shaped oil seal with the inner tube, as well as the areas on the outer wall of the inner tube corresponding to the oil seal sealing sections, are all coated with a fluororubber coating. This utility model improves sealing effect, lifespan, and corrosion resistance through a multi-layer protection mechanism consisting of a corrosion-resistant material layer, a fluid dynamic damping layer, and a physical barrier layer.

Description

Technical Field

[0001] This utility model belongs to the field of electric linear actuator technology, and in particular relates to a multi-layer composite waterproof structure for the pushing end of an electric linear actuator. Background Technology

[0002] As a core component of linear drive devices, electric linear actuators are widely used in solar thermal power plants, industrial automation, medical devices, and other applications. Especially under extreme conditions such as high temperature, high humidity, and strong corrosion, stringent requirements are placed on the waterproof sealing performance of the actuators. Existing waterproof structures at the actuating end of electric linear actuators typically employ a single-layer sealing ring or a static sealing design, which has the following technical shortcomings:

[0003] Short sealing life: Traditional rubber seals (such as O-rings) are prone to sealing failure due to friction, wear and thermal aging during dynamic expansion and contraction. Especially in a wide temperature range of -40℃ to 120℃ (such as solar thermal power plants with high temperature and high humidity environments), the performance of rubber materials drops sharply, and the sealing life is generally less than 20,000 cycles, which cannot meet the long-term operation requirements of solar thermal power plants and other scenarios.

[0004] Insufficient corrosion protection: As a component that directly contacts the external environment, the inner tube is prone to corrosion due to moisture penetration under high temperature and humidity conditions, which in turn leads to accelerated wear of the sealing surface and increased driving resistance. In existing technologies, the surface treatment of the inner tube mostly adopts ordinary galvanizing or painting processes, which are insufficient in corrosion resistance, with a corrosion rate as high as 30% or more, seriously affecting the service life of the push rod.

[0005] The sealing structure is too simple: existing waterproof designs mostly rely on a single physical barrier (such as the compression of a sealing ring), lacking the synergistic protection of hydrodynamic damping and material corrosion resistance. Under conditions of high-speed expansion and contraction or pressure fluctuations, water vapor can easily penetrate through the sealing gaps, leading to short circuits in the internal drive module or failure of the lubricating grease.

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

[0007] The purpose of this utility model is to provide a multi-layer composite waterproof structure for the push end of an electric push rod, which improves the sealing effect, lifespan and corrosion resistance through a multi-layer protection mechanism.

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

[0009] A multi-layer composite waterproof structure for the push end of an electric actuator includes an inner tube and an outer tube sleeved outside the inner tube. The inner tube is driven by a lead screw at the output end of a drive module to extend and retract along the axial direction of the outer tube. A fixed seat is fixedly connected to the top end face of the outer tube. The telescopic end of the inner tube passes through the fixed seat and extends outside the fixed seat. A lower waterproof groove and an upper waterproof groove are sequentially provided on the inner wall of the fixed seat along the extension direction of the inner tube. A lip seal is installed in the upper waterproof groove, and a Y-shaped oil seal is installed in the lower waterproof groove. The fixed seat forms a dynamic sealing connection with the inner tube through the lip seal and the Y-shaped oil seal. The dynamic contact surfaces of the lip seal and the Y-shaped oil seal with the inner tube, as well as the areas on the outer wall of the inner tube corresponding to the sealing sections of the oil seals, are all coated with a fluororubber coating.

[0010] As an improvement to the multi-layer composite waterproof structure of the electric push rod driving end of this utility model, the lip of the lip seal is Y-shaped and presses against the inner tube.

[0011] As an improvement to the multi-layer composite waterproof structure of the electric push rod driving end of this utility model, an annular upper groove is provided on the inner wall of the fixed base at the end away from the lower waterproof groove, and the upper groove is connected to the upper waterproof groove.

[0012] As an improvement to the multi-layer composite waterproof structure of the electric push rod push end of this utility model, a guide ring is installed in the groove on the inner wall of the fixed seat. The guide ring is sleeved on the inner tube and located between the lip seal and the Y-shaped seal.

[0013] As an improvement to the multi-layer composite waterproof structure of the electric push rod's driving end of this utility model, the guide ring is made of polytetrafluoroethylene, and the thickness of the guide ring is greater than the depth of the groove.

[0014] As an improvement to the multi-layer composite waterproof structure of the electric push rod push end of this utility model, the fixed seat and the outer tube are sealed together by a sealing ring, and trunnions are respectively inserted on the two corresponding sides of the fixed seat.

[0015] As an improvement of the multi-layer composite waterproof structure of the electric push rod of this utility model, the lead screw is connected to the inner tube through a slide block. A magnet is fixedly installed on the slide block. Two magnetic induction switches are provided on the outer wall of the outer tube. 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.

[0016] As an improvement to the multi-layer composite waterproof structure of the electric push rod of this utility model, a dust cover is provided on the outer wall of the outer tube along its axial direction to form an installation cavity, and the two magnetic induction switches are installed in the installation cavity.

[0017] As an improvement to the multi-layer composite waterproof structure of 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, and the gap between the self-aligning ball bearing and the connector is filled with glue.

[0018] As an improvement of the multi-layer composite waterproof structure of the electric push rod push end of this utility model, the self-aligning ball bearing is connected to the joint through injection molding process, and 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.

[0019] Compared with existing technologies, the multi-layer composite waterproof structure of the electric actuator push end of this utility model improves the sealing effect, service life and corrosion resistance through the following multi-layer protection mechanisms:

[0020] Corrosion-resistant material layer: A fluororubber coating is applied to the dynamic contact surface between the inner tube and the lip seal and Y-shaped oil seal, as well as the sealing section area on the outer wall of the inner tube that seals with the oil seal. The high temperature resistance and chemical corrosion resistance of fluororubber are used to reduce the corrosion rate of the inner tube.

[0021] Fluid dynamic damping layer: Various waterproof grooves are set on the inner wall of the fixed seat to increase the permeation resistance by changing the fluid flow direction. Combined with the low surface energy characteristics of the fluororubber coating, water film adhesion is reduced, forming a fluid damping effect.

[0022] Physical barrier layer: It adopts a combination of lip seal and Y-shaped seal to dynamically fit the inner tube and work together to block the water vapor penetration path. Attached image description:

[0023] Figure 1 These are the front view and partial sectional view of the electric linear actuator of this utility model;

[0024] Figure 2 yes Figure 1 Enlarged view of a partial sectional view;

[0025] Figure 3 yes Figure 2 Enlarged view of point A in the middle;

[0026] Figure 4 This is a three-dimensional exploded and enlarged view of some components of the electric linear actuator of this utility model;

[0027] Figure 5 This is a three-dimensional enlarged sectional view of the fixing base and various oil seals of this utility model;

[0028] Figure 6 This is a three-dimensional enlarged sectional view of the lip seal of this utility model;

[0029] Figure 7This is a three-dimensional sectional enlarged view of the Y-shaped oil seal of this utility model;

[0030] Figure 8 This is a three-dimensional enlarged view of the connector and self-aligning ball bearing of this utility model after injection molding.

[0031] Illustration:

[0032] 1. Inner tube; 2. Outer tube; 21. Anti-sway ring; 22. Magnetic induction switch; 3. Fixing base; 31. Upper waterproof groove; 311. Upper groove; 32. Lower waterproof groove; 33. Groove; 34. Sealing ring; 35. Trunnion; 4. Lip seal; 41. Lip edge; 5. Y-shaped oil seal; 6. Guide ring; 7. Drive module; 71. Lead screw; 72. Protective cover; 8. Connector; 81. Self-aligning ball bearing; 82. Glue injection. 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 8 A multi-layer composite waterproof structure for the push end of an electric actuator includes an inner tube 1 and an outer tube 2. The outer tube 2 is sleeved outside the inner tube 1. The inner tube 1 is driven by the lead screw 71 at the output end of the drive module 7 to extend and retract along the axial direction of the outer tube 2. A fixed seat 3 is fixedly connected to the top end face of the outer tube 2. The telescopic end of the inner tube 1 passes through the fixed seat 3 and extends outside the fixed seat 3. A lower waterproof groove 32 and an upper waterproof groove 31 are sequentially provided on the inner wall of the fixed seat 3 along the extension direction of the inner tube 1 (i.e., from bottom to top). A lip seal 4 is installed in the upper waterproof groove 31, and a Y-shaped oil seal 5 is installed in the lower waterproof groove 32. The fixed seat 3 forms a dynamic sealing connection with the inner tube 1 through the lip seal 4 and the Y-shaped oil seal 5. The dynamic contact surfaces of the lip seal 4 and the Y-shaped oil seal 5 with the inner tube 1, as well as the areas on the outer wall of the inner tube 1 corresponding to the oil seal sealing sections, are coated with a fluororubber coating.

[0035] Reference Figure 1 and Figure 4 The drive module 7 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 71. 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 71 to rotate. Therefore, the lead screw 71 is located at the output end of the drive module 7.

[0036] Reference Figure 4The lead screw 71 is connected to the inner tube 1 via a slide block. The slide block is sleeved on the lead screw 71 and threadedly connected to the lead screw 71. The slide block is located inside the outer tube 2 and is slidably connected to the inner wall of the outer tube 2. The inner tube 1 is coaxially fixed to the top of the slide block. A magnet is fixedly installed on the slide block. Two magnetic induction switches 22 are provided on the outer wall of the outer tube 2. The two magnetic induction switches 22 are distributed at both ends of the outer tube 2 along its axial direction to sense the position of the magnet. A protective cover 72 is provided on the outer wall of the outer tube 2 along its axial direction to form an installation cavity. The two magnetic induction switches 22 are installed in the installation cavity. The motor in the drive module 7 drives the worm gear to rotate. The worm gear drives the worm wheel to rotate. The worm wheel drives the lead screw 71 to rotate. The lead screw 71 drives the inner tube 1 to extend and retract along the axial direction of the outer tube 2 via the slide block. The two magnetic induction switches 22 can detect the extension and retraction length of the inner tube 1 by sensing the position of the magnet on the slide block.

[0037] Reference Figure 2 , Figure 3 , Figure 4 and Figure 5 The fixing seat 3 is fixed to the top end face of the outer tube 2 by four screws. The lower end of the fixing seat 3 is inserted into the outer tube 2 and sealed to the outer tube 2 by an annular sealing ring 34. The inner wall of the fixing seat 3 is provided with an annular upper groove 311 at the end away from the lower waterproof groove 32. The upper groove 311 is connected to the upper waterproof groove 31. Both the upper waterproof groove 31 and the lower waterproof groove 32 are annular. The inner wall of the fixing seat 3 is also provided with an annular groove 33. The groove 33 is located between the upper waterproof groove 31 and the lower waterproof groove 32. Both the upper waterproof groove 31 and the lower waterproof groove 32 are annular. An annular anti-sway ring 21 is provided at the end of the outer tube 2 near the fixing seat 3. The anti-sway ring 21 is sleeved on the outside of the inner tube 1. Trunnions 35 are inserted into the two corresponding sides of the fixing seat 3.

[0038] Reference Figure 3 , Figure 4 , Figure 5 and Figure 7 The Y-shaped oil seal 5 is generally annular, and the top surface of the Y-shaped oil seal 5 is provided with an annular top groove along its circumference, so that the radial cross section of the Y-shaped oil seal 5 is Y-shaped.

[0039] Reference Figure 2 , Figure 3 and Figure 5 An annular guide ring 6 is installed in the groove 33 on the inner wall of the fixed seat 3. The guide ring 6 is sleeved on the inner tube 1 and located between the lip seal 4 and the Y-shaped seal 5. The guide ring 6 is made of polytetrafluoroethylene and the thickness of the guide ring 6 is greater than the depth of the groove 33.

[0040] Reference Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6The lip seal 4 is generally annular, and the inner wall of the lip seal 4 is provided with an annular side groove along its circumference, thereby forming a lip edge 41 with a radial cross section of Y shape, which presses against the inner tube 1.

[0041] Reference Figure 2 and Figure 8 A connector 8 is fixedly connected to the top of the extended end 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.

[0042] Reference Figures 1 to 8 This utility model features a multi-layer composite waterproof structure at the push end of the electric actuator. A lip seal 4, multiple waterproof grooves, and a fluororubber coating are sequentially installed at the upper end of the inner tube 1, forming a triple protection system of "physical barrier + fluid damping + material corrosion resistance." Under operating conditions of -40℃ to 120℃, the waterproof lifespan of the electric actuator can be increased to over 100,000 cycles, and the corrosion rate of the inner tube 1 is reduced by 90%. This electric actuator is primarily suitable for solar thermal power plants with high-temperature and high-humidity environments.

[0043] This utility model features a multi-layer composite waterproof structure at the push end of an electric actuator. Through a triple protection mechanism of "physical barrier + fluid damping + material corrosion resistance," it achieves a breakthrough improvement in sealing life and corrosion resistance.

[0044] Physical barrier layer: A combination sealing structure of lip seal 4 and Y-shaped seal 5 is adopted. The flexible lip 41 of lip seal 4 forms a dynamic fit with the inner tube 1, and the two work together to block the water vapor penetration path.

[0045] Fluid damping layer: A waterproof groove is set on the inner wall of the fixed seat 3. By changing the direction of fluid flow, the permeation resistance is increased. Combined with the low surface energy characteristics of the fluororubber coating, water film adhesion is reduced, forming a fluid dynamic damping effect.

[0046] Corrosion-resistant material: A fluororubber coating is applied to the dynamic contact surface between the inner tube 1 and the oil seal, as well as the corresponding sealing section area. This material has excellent high temperature resistance (can withstand 260℃ for a long time), chemical corrosion resistance (resistant to acids, alkalis, and salt spray), and low coefficient of friction (μ≤0.2), which reduces the corrosion rate of the inner tube 1 by more than 90%.

[0047] The electric actuator of this invention has a waterproof lifespan of over 100,000 cycles under operating conditions ranging from -40℃ to 120℃, which is five times longer than that of traditional structures. It is especially suitable for high-temperature and high-humidity environments such as the concentrator tracking system of solar thermal power plants, and significantly reduces equipment maintenance costs and downtime risks.

[0048] 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. A multi-layer composite waterproof structure of an electric push rod pushing end, comprising an inner tube and an outer tube sleeved outside the inner tube, the inner tube is driven by a lead screw at the output end of a driving module to stretch and retract along the axial direction of the outer tube, characterized in that, A fixing seat is fixedly connected to the top end face of the outer tube. The telescopic end of the inner tube passes through the fixing seat and extends outside the fixing seat. A lower waterproof groove and an upper waterproof groove are sequentially provided on the inner wall of the fixing seat along the extension direction of the inner tube. A lip seal is installed in the upper waterproof groove, and a Y-shaped oil seal is installed in the lower waterproof groove. The fixing seat forms a dynamic sealing connection with the inner tube through the lip seal and the Y-shaped oil seal. The dynamic contact surfaces of the lip seal and the Y-shaped oil seal with the inner tube, as well as the areas on the outer wall of the inner tube corresponding to the oil seal sealing sections, are all coated with a fluororubber coating.

2. The multi-layer composite waterproof structure of the electric actuator push end according to claim 1, characterized in that, The lip of the lip seal is Y-shaped and presses against the inner tube.

3. The multi-layer composite waterproof structure of the electric actuator push end according to claim 1, characterized in that, The inner wall of the fixing seat has an annular upper groove at one end away from the lower waterproof groove, and the upper groove is connected to the upper waterproof groove.

4. The multi-layer composite waterproof structure of the electric actuator push end according to claim 1, characterized in that, A guide ring is installed in the groove on the inner wall of the fixed seat. The guide ring is sleeved on the inner tube and located between the lip seal and the Y-shaped seal.

5. The multi-layer composite waterproof structure of the electric actuator push end according to claim 4, characterized in that, The guide ring is made of polytetrafluoroethylene, and the thickness of the guide ring is greater than the depth of the groove.

6. The multi-layer composite waterproof structure of the electric actuator push end according to claim 1, characterized in that, The fixed base and the outer tube are sealed together by a sealing ring, and trunnions are inserted into the two corresponding sides of the fixed base.

7. The multi-layer composite waterproof structure of the electric actuator push end according to claim 1, characterized in that, The lead screw is connected to the inner tube via a slide block. A magnet is fixedly mounted on the slide block. Two magnetic induction switches are provided on the outer wall of the outer tube. 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.

8. The multi-layer composite waterproof structure of the electric actuator push end according to claim 7, characterized in that, The outer wall of the outer tube is sealed with a dust cover along its axial direction, forming an installation cavity, and the two magnetic induction switches are installed in the installation cavity.

9. The multi-layer composite waterproof structure of the electric actuator push end 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.

10. The multi-layer composite waterproof structure of the electric actuator push end according to claim 9, 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.

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