An underwater electric cylinder

Abstract

This utility model relates to the field of electric cylinder technology and provides an underwater electric cylinder, including a cylinder body and a push rod that moves axially within it. A first sealing element is embedded in the end of the cylinder body, sleeved on the outer wall of the push rod. The first sealing element contains a first sealing lip and a second sealing lip that conform to the outer wall of the push rod. The first sealing lip has a hollow conical structure that tapers towards the external medium, allowing it to deform radially inward under pressure. This utility model overcomes the shortcomings of existing technologies, featuring a reasonable design and compact structure. The first sealing lip utilizes water pressure to trigger radial contraction deformation, actively enhancing the clamping force on the push rod. The second sealing lip achieves static sealing through sharp corner contact. A pre-reserved deformation space between the two lips forms a pressure-adaptive sealing system, effectively preventing the intrusion of water. The annular groove at the bottom isolates the deformation stress of the second sealing lip, effectively preventing overall twisting failure of the sealing element.

Description

Technical Field

[0001] This utility model relates to the field of electric cylinder technology, specifically to an electric cylinder for underwater use. Background Technology

[0002] With the continuous development of marine development and underwater engineering, the demand for execution equipment capable of stable underwater operation is increasing. Electric cylinders, as devices that convert the rotational motion of a motor into linear motion, have broad application prospects in underwater operations due to their advantages such as high positioning accuracy and fast response speed. However, the complex underwater environment, with its high pressure, corrosion, and other adverse factors, places extremely high demands on the sealing performance and operational stability of electric cylinders.

[0003] Chinese utility model patent application number CN202221527558.1 discloses a novel underwater electric cylinder, relating to the field of electric cylinder technology. The cylinder includes a cylinder body with symmetrical through holes along its central axis. A shaft is installed in one of the through holes on the outer wall of the cylinder body. A double round nut is fitted between the shaft and the inner wall of the through hole. A ball screw is installed at one end of the shaft via a pusher groove. A nut is fitted on the outer wall of the ball screw, and a push rod is fitted on the outer wall of the nut. A copper sleeve is engaged on the outer wall of the push rod. Keyways are provided on both the top and bottom surfaces of the cylinder body, and these keyways engage with the outer wall of the nut.

[0004] The above structure uses a rotary oil seal design to prevent water molecules from entering the cylinder. However, the applicable pressure for conventional rotary oil seals underwater is usually less than 0.05 MPa. At a depth of 5m underwater, the water pressure is generally around 0.05 MPa. This means that using conventional rotary oil seals may result in water leakage. Therefore, we propose an electric cylinder for underwater use. Utility Model Content

[0005] In view of the shortcomings of the prior art, this utility model provides an underwater electric cylinder to solve the above-mentioned problems in the prior art.

[0006] To achieve the above objectives, this utility model is implemented through the following technical solution: an underwater electric cylinder, including a cylinder body and a push rod that moves along its axial direction inside the cylinder body. A first sealing element is embedded in the end of the cylinder body. The first sealing element is sleeved on the outer wall of the push rod. It has a first sealing lip and a second sealing lip that fit against the outer wall of the push rod. The first sealing lip has a hollow conical structure and gradually shrinks towards the external medium side so that it deforms radially inward after being pressed.

[0007] The second sealing lip has a sharp angle structure and forms a line contact with the outer wall of the push rod. There is a space between the first sealing lip and the second sealing lip to allow them to come together.

[0008] The first seal has fitting portions on its upper, lower, and side walls that are embedded inside the cylinder body;

[0009] The bottom of the first seal has an annular groove to block the stress transmission path generated when the second sealing lip is deformed under pressure.

[0010] Furthermore, a second seal is provided on the side of the cylinder body near the first seal. The inner wall of the second seal is fitted and sleeved on the outer wall of the push rod. It has a first extrusion lip with a sharp angle extending inward and a second extrusion lip with a sharp angle extending outward. The side of the second seal facing the first seal is tapered both inward and outward to form an inclined external medium bearing surface, which is used to increase the tightness between the second seal and the cylinder body and the push rod when under pressure.

[0011] Furthermore, the cylinder body is provided with a lead screw, the end of which is provided with a drive unit to drive it to rotate along its own axis. The outer wall of the lead screw is threaded with a lead screw nut. One side of the lead screw nut is engaged with the outside of the push rod to drive the push rod to reciprocate. The inner wall of the cylinder body is provided with a guide plate along its axial direction. The outer wall of the lead screw nut is provided with a keyway that matches the guide plate to restrict the rotation of the lead screw nut.

[0012] Furthermore, the drive unit includes a drive source mounted on the cylinder block, the output end of the drive source is connected to a drive gear, the outer wall of the drive gear is meshed with a transmission gear, and the outer wall of the transmission gear is meshed with a driven gear.

[0013] Furthermore, the upper and lower walls of the fitting part are embedded in the annular groove on the inner wall of the cylinder to achieve axial positioning;

[0014] The sidewall of the fitting part has a dovetail-shaped structure, which cooperates with the corresponding wedge-shaped groove of the cylinder to prevent radial dislodgement.

[0015] Furthermore, several waterproof and breathable valves are installed on the cylinder body.

[0016] This utility model provides an underwater electric cylinder, which has the following beneficial effects:

[0017] 1. The first sealing lip utilizes water pressure to trigger radial contraction deformation, actively enhancing the clamping force on the push rod. The second sealing lip achieves static sealing through sharp corner contact. The pre-reserved deformation space between the two lips forms a pressure-adaptive sealing system, effectively blocking the intrusion of water media. Its bottom annular groove isolates the deformation stress of the second sealing lip, effectively preventing the overall twisting failure of the seal.

[0018] 2. The second seal has two compression lips. During installation, the deformation enhances the seal, and the pressure-bearing surface further strengthens the tightness when the first seal leaks, forming a double protection to effectively prevent moisture from entering.

[0019] 3. The nut engages with the guide plate via a keyway. When the drive unit stops, the nut is limited by the guide plate and cannot rotate, preventing the push rod from moving under external forces such as water pressure. The drive source uses a servo motor with self-locking, plus an inefficient reverse transmission of the gear set, to jointly resist the water pressure thrust and prevent the push rod from retracting uncontrolled. The triple self-locking mechanism ensures the self-locking performance of the push rod. Attached Figure Description

[0020] Figure 1 This is a three-dimensional schematic diagram of the overall structure of this utility model;

[0021] Figure 2 This utility model Figure 1 Vertical sectional view of the structure;

[0022] Figure 3 This is a cross-sectional schematic diagram of the push rod structure of this utility model;

[0023] Figure 4 This is a three-dimensional schematic diagram of the drive unit structure of this utility model;

[0024] Figure 5 This is a three-dimensional schematic diagram of the structure of the first sealing element of this utility model;

[0025] Figure 6 This is a bottom-view perspective view of the structure of the first sealing element of this utility model;

[0026] Figure 7 This is a cross-sectional view of the structure of the first sealing element of this utility model;

[0027] Figure 8 This is a three-dimensional schematic diagram of the structure of the second sealing element of this utility model;

[0028] Figure 9 This is a cross-sectional view of the structure of the second sealing element of this utility model.

[0029] In the diagram: 1. Cylinder body; 2. Push rod; 3. First seal; 31. First sealing lip; 32. Second sealing lip; 33. Fitting part; 34. Groove; 4. Second seal; 41. First extrusion lip; 42. Second extrusion lip; 5. Lead screw; 6. Nut; 7. Guide plate; 81. Drive source; 82. Drive gear; 83. Transmission gear; 84. Driven gear; 9. Waterproof and breathable valve. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0031] See attached document Figure 1-9 An underwater electric cylinder suitable for use at a depth of 5m includes a cylinder body 1 and a push rod 2 that moves along its axial direction inside the cylinder body 1. A first sealing element 3 is embedded in the end of the cylinder body 1. The first sealing element 3 is sleeved on the outer wall of the push rod 2. It has a first sealing lip 31 and a second sealing lip 32 that fit against the outer wall of the push rod 2. The double lips cooperate to prevent the intrusion of high-pressure water and ensure that the electric cylinder can be used normally in deep water.

[0032] The first sealing lip 31 has a hollow conical structure and gradually tapers towards the external medium. Its conical outer wall contacts the external medium. When the electric cylinder is used at a depth of 5 meters underwater, the water pressure will squeeze the conical outer wall of the first sealing lip 31, causing it to deform inward. This further causes the first sealing lip 31 to deform radially inward after being pressed, thus fitting more tightly to the outer wall of the push rod 2 and enhancing the sealing effect.

[0033] The second sealing lip 32 has a sharp angle structure and forms a line contact with the outer wall of the push rod 2, which enhances the sealing effect and reduces friction with the push rod 2. The first sealing lip 31 and the second sealing lip 32 have a space to come together, which can ensure that the two deform under pressure to increase the tightness of the fit with the outer wall of the push rod 2.

[0034] The upper, lower and side walls of the first sealing member 3 are provided with fitting parts 33 that are embedded inside the cylinder body 1 to ensure the seal between the first sealing member 3 and the cylinder body 1;

[0035] The bottom of the first seal 3 is provided with an annular groove 34, which is used to block the stress transmission path generated when the second sealing lip 32 is deformed under pressure, so as to avoid large deformation of the upper, lower and side walls of the first seal 3, which would affect the seal between the first seal 3 and the cylinder 1.

[0036] Furthermore, the upper and lower walls of the fitting part 33 are embedded in the annular groove of the inner wall of the cylinder 1 to achieve axial positioning, thereby preventing the first seal 3 from moving axially and causing leakage.

[0037] The sidewall of the fitting part 33 has a dovetail-shaped structure, which cooperates with the wedge-shaped groove corresponding to the cylinder body 1 to prevent radial dislodgement, ensuring the stability of the first seal 3 in the cylinder body 1, so that it can effectively play a sealing role and avoid sealing failure caused by seal displacement.

[0038] In this embodiment, a second seal 4 is provided inside the cylinder body 1 on the side close to the first seal 3. The inner wall of the second seal 4 is fitted and sleeved on the outer wall of the push rod 2. It has a first extrusion lip 41 extending inward with a sharp angle structure inside and a second extrusion lip 42 extending outward with a sharp angle structure outside. The two extrusion lips are extruded and deformed during installation, which enhances the sealing between the second seal 4, the push rod 2 and the cylinder body 1.

[0039] The second seal 4 is tapered both inside and out on the side facing the first seal 3 to form an inclined external medium-bearing surface. This increases the tightness between the second seal 4 and the cylinder 1 and push rod 2 when under pressure. When the first seal 3 leaks, water pressure acts on the medium-bearing surface of the second seal 4, causing the first extrusion lip 41 and the second extrusion lip 42 to deform away from the first seal 3. This further enhances the tightness between the second seal 4 and the push rod 2 and cylinder 1, increases the sealing effect, and effectively prevents water from entering the electric cylinder.

[0040] In this embodiment, a lead screw 5 is provided inside the cylinder body 1, and a drive unit is provided at its end to drive it to rotate along its own axis. A lead screw nut 6 is threadedly connected to the outer wall of the lead screw 5. One side of the lead screw nut 6 is engaged with the outside of the push rod 2 to drive the push rod 2 to reciprocate. A guide plate 7 is installed on the inner wall of the cylinder body 1 along its axial direction. A keyway is opened on the outer wall of the lead screw nut 6 to cooperate with the guide plate 7. When the drive unit drives the lead screw 5 to rotate, the lead screw nut 6 is restricted from rotating by cooperating with the guide plate 7 through the keyway, so that the lead screw nut 6 can only move linearly along the axial direction of the lead screw 5, thereby driving the push rod 2 to reciprocate, so as to ensure that the electric cylinder can operate normally underwater. When the drive unit stops working, the lead screw nut 6 is limited by the guide plate 7 and cannot rotate on the lead screw 5, effectively preventing the push rod 2 from moving under the action of external forces such as water pressure, and enhancing the reliability of self-locking.

[0041] In this embodiment, the drive unit includes a drive source 81 mounted on the cylinder 1. The output end of the drive source 81 is connected to a drive gear 82. The outer wall of the drive gear 82 is meshed with a transmission gear 83, and the outer wall of the transmission gear 83 is meshed with a driven gear 84. When the drive source 81 is started, the drive gear 82 drives the transmission gear 83 to rotate, which in turn drives the driven gear 84 to rotate, thereby realizing the rotation of the lead screw 5. The drive source 81 uses a servo motor with self-locking, which can further ensure the self-locking performance of the push rod 2 and prevent it from retracting into the cylinder 1 due to water pressure.

[0042] In this embodiment, in order to ensure the stable operation of the electric cylinder when used underwater, several waterproof and breathable valves 9 are installed on the cylinder body 1. These valves can ensure that the inside of the electric cylinder is connected to the outside air while preventing external moisture from entering the inside of the electric cylinder. The waterproof and breathable valves 9 can balance the internal and external air pressure and avoid damage to the seals due to the air pressure difference, which would affect the normal use of the electric cylinder.

[0043] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0044] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. An underwater electric cylinder, comprising a cylinder body (1) and a push rod (2) that moves along its axial direction within the cylinder body, characterized in that: The cylinder body (1) is fitted with a first sealing element (3) at the end. The first sealing element (3) is sleeved on the outer wall of the push rod (2). It has a first sealing lip (31) and a second sealing lip (32) that fit the outer wall of the push rod (2). The first sealing lip (31) has a hollow conical structure and gradually shrinks towards the external medium side so that it deforms radially inward after being pressed. The second sealing lip (32) has a sharp angle structure and forms a line contact with the outer wall of the push rod (2). There is a space between the first sealing lip (31) and the second sealing lip (32) that allows them to approach each other. The first sealing member (3) has fitting parts (33) embedded in the cylinder body (1) on its upper, lower and side walls; The bottom of the first seal (3) is provided with an annular groove (34) to block the stress transmission path generated when the second sealing lip (32) is deformed under pressure.

2. The underwater electric cylinder as described in claim 1, characterized in that: The cylinder (1) has a second seal (4) on the side close to the first seal (3). The inner wall of the second seal (4) is fitted and sleeved on the outer wall of the push rod (2). It has a first extrusion lip (41) extending inward with a sharp angle structure and a second extrusion lip (42) extending outward with a sharp angle structure. The side of the second seal (4) facing the first seal (3) is gradually narrowed both inside and out to form an inclined external medium bearing surface, which is used to increase the tightness between the second seal (4) and the cylinder (1) and the push rod (2) when under pressure.

3. An underwater electric cylinder as described in claim 1 or 2, characterized in that: The cylinder (1) is provided with a lead screw (5), and its end is provided with a drive unit that drives it to rotate along its own axis. The outer wall of the lead screw (5) is threaded with a lead nut (6). One side of the lead nut (6) is engaged with the outside of the push rod (2) to drive the push rod (2) to reciprocate. The inner wall of the cylinder (1) is provided with a guide plate (7) along its axial direction. The outer wall of the lead nut (6) is provided with a keyway that matches the guide plate (7) to restrict the rotation of the lead nut (6).

4. The underwater electric cylinder as described in claim 3, characterized in that: The drive unit includes a drive source (81) mounted on the cylinder (1), the output end of the drive source (81) is connected to a drive gear (82), the outer wall of the drive gear (82) is meshed with a transmission gear (83), and the outer wall of the transmission gear (83) is meshed with a driven gear (84).

5. The underwater electric cylinder as described in claim 1, characterized in that: The upper and lower walls of the fitting part (33) are embedded in the annular groove of the inner wall of the cylinder (1) to achieve axial positioning; The sidewall of the fitting part (33) has a dovetail-shaped structure, which cooperates with the corresponding wedge groove of the cylinder body (1) to prevent radial dislodgement.

6. The underwater electric cylinder as described in claim 1, characterized in that: Several waterproof and breathable valves (9) are installed on the cylinder body (1).

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