A jack
By adopting an inner and outer convex edge limiting structure and a threaded rod design in the jack, the problem of piston rod collisions and scratches damaging the sealing components is solved, achieving a leak-free hydraulic system and a wider range of applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- WENLING DINGSHANG ELECTROMECHANICAL
- Filing Date
- 2025-09-10
- Publication Date
- 2026-07-07
AI Technical Summary
The piston rod of existing vertical jacks is prone to bumps and scratches during extension and retraction, which leads to wear of the sealing components and leakage of hydraulic oil.
The design incorporates an inner and outer convex edge structure. The sealing ring is fitted onto the outer side of the outer convex edge, with the inner and outer convex edges abutting and limiting each other. A threaded rod is screwed into the top rod to increase the contact area of the sealing ring, reduce the pressure per unit area, and prevent bumps and wear.
It effectively avoids the impact and wear of the sealing ring, prevents hydraulic oil leakage, and increases the lifting height and application range of the jack.
Smart Images
Figure CN224467444U_ABST
Abstract
Description
Technical fields:
[0001] This utility model belongs to the technical field of hydraulic lifting tools, specifically referring to a jack. Background technology:
[0002] Chinese utility model patent (publication number CN222099442U, application date 2024.05.06, publication date 2024.12.03) discloses a three-section vertical jack, including a base, a hydraulic oil tank, a top cap, a first piston rod, a second piston rod, and a third piston rod. The hydraulic oil tank is mounted on the base and has a cylinder inside. An oil storage chamber is formed between the outer wall of the cylinder and the inner wall of the hydraulic oil tank. The top cap is engaged with the upper part of the hydraulic oil tank and the upper part of the cylinder. Piston rod, second piston rod, and third piston rod are sequentially sleeved from the inside out. The third piston rod passes through the piston rod hole in the center of the top cap and is positioned inside the cylinder cavity of the hydraulic cylinder. The second piston rod has a first sealing assembly on the upper part of its inner cavity wall that seals with the first piston rod. The third piston rod has a second sealing assembly on the upper part of its inner cavity wall that seals with the second piston rod. The top cap has a third sealing assembly on the inner wall of its piston rod hole that seals with the third piston rod.
[0003] The shortcomings of the above-mentioned vertical jack are that the first, second, and third piston rods are prone to bumps and scratches during extension and retraction. Once scratches appear on the rods, they will directly wear down or even cut the corresponding sealing components, leading to hydraulic oil leakage. Utility model content:
[0004] The purpose of this utility model is to provide a jack that is free from bumps, scratches, and wear and tear on the sealing ring, effectively preventing hydraulic oil leakage.
[0005] This utility model is implemented as follows:
[0006] A jack includes a hydraulic cylinder fixedly mounted on a base plate at its lower end. A hollow, open-top and open-bottomed push rod slidably inside the hydraulic cylinder. A hollow, open-top and open-bottomed push rod slidably inside the push rod 1. A plug is sealed at the lower end of the push rod 2. An outer flange protrudes outward from the lower end of the push rod and the lower end of the plug. An inner flange protrudes inward from the upper end of the push rod 1 and the upper end of the hydraulic cylinder. The inner flange abuts against the corresponding outer flange, providing upper limit. A sealing ring is fitted over the outer flange, sealing the gap between the outer sidewall and the corresponding inner sidewall of the outer flange. A threaded rod is threaded into the push rod 2, and a top plate is fixedly mounted on the upper end of the threaded rod above the push rod 2.
[0007] In the aforementioned jack, two or more push rods are coaxially arranged and sequentially sleeved from the inside out. The outermost push rod's outer protrusion abuts and limits the movement against the inner protrusion of the cylinder. A sealing ring fitted outside the outermost push rod seals the gap between the inner wall of the cylinder and the outer wall of the outermost push rod's outer protrusion. The outer protrusions and inner protrusions of two adjacent push rods abut and limit the movement. The inner wall of the outermost push rod and the outer wall of its adjacent inner push rod are sealed by a sealing ring. The inner protrusion of the innermost push rod abuts and limits the movement against the outer protrusion of the plug. A sealing ring fitted outside the outer protrusion of the plug seals the gap between the inner wall of the innermost push rod and the outer wall of the plug's outer protrusion.
[0008] In the aforementioned type of jack, a retaining spring is attached to the inner side of the lower end of the push rod. The retaining spring of the outer push rod 1 limits the lower position of the adjacent inner push rod 1, and the retaining spring of the innermost push rod 1 limits the lower position of the plug.
[0009] In the aforementioned type of jack, the upper end of the plug extends into the second push rod, and the upper end of the plug is fixedly connected to the second push rod. The lower end face of the second push rod abuts against the upper end face of the outer protruding edge of the plug.
[0010] In the aforementioned type of jack, the upper end of the plug can be tightly connected to the push rod, or it can be screwed or welded.
[0011] In the aforementioned type of jack, the outer side wall of the convex edge is recessed to form an annular groove, and the sealing ring is disposed within the annular groove.
[0012] In the aforementioned type of jack, each outer convex edge is provided with two or more annular grooves, and correspondingly, each outer convex edge is fitted with two or more sealing rings.
[0013] In the aforementioned jack, the lower end of the threaded rod is provided with a limiting structure to prevent the threaded rod from completely unscrewing out of the top rod. The threaded rod is a hollow structure, and the lower end of the top plate is provided with a mounting post that extends into the threaded rod. The mounting post is fixedly connected to the threaded rod.
[0014] In the aforementioned type of jack, the limiting structure may be provided when the external thread of the threaded rod is not provided at the bottom of the threaded rod; the limiting structure may also be provided at the lower end of the threaded rod with a weld point that seals its external thread.
[0015] In the aforementioned type of jack, the mounting column and the threaded rod can be tightly fitted together, screwed together, or welded together.
[0016] In the aforementioned type of jack, the top plate is cylindrical, and the upper surface of the top plate is recessed to form a cross groove, the center of which coincides with the center of the top plate.
[0017] In one of the aforementioned jacks, the top plate has anti-slip protrusions on its upper surface.
[0018] In the aforementioned jack, the lower end of the cylinder has an outwardly protruding mounting flange, the base plate is provided with a pressure plate for pressing on the mounting flange, the bottom of the cylinder is provided with a sealing ring two for sealing the gap between the cylinder and the base plate, and the base plate is provided with an oil passage connecting the inner cavity of the cylinder and the outside.
[0019] In one of the aforementioned jacks, the lower surface of the hydraulic cylinder is concave to form an annular groove for setting a second sealing ring.
[0020] In one of the aforementioned jacks, a gear pump is installed on the base plate, and the gear pump is connected to the inner cavity of the oil cylinder through the oil passage. An oil tank is provided on the base plate surrounding the oil cylinder, and the oil tank is connected to the gear pump.
[0021] The outstanding advantages of this utility model compared to the prior art are:
[0022] This invention features an outwardly protruding edge at the lower end of the push rod and the lower end of the plug, and an inwardly protruding edge at the upper end of the push rod and the upper end of the cylinder. The inner protruding edges abut against the corresponding outer protruding edges, providing upper limit positioning. A sealing ring is fitted over the outer protruding edges, sealing the gap between the outer wall of the outer protruding edge and the corresponding inner wall. Both the outer wall of the outer protruding edge and the corresponding inner wall, which are in contact with the sealing ring, are located internally and do not protrude externally, eliminating the problems of bumping, scratching, or abrasion on the sealing ring, effectively preventing hydraulic oil leakage. Furthermore, because the sealing ring is fitted over the outer protruding edge, compared to being fitted onto a slender push rod, the sealing ring has a longer circumference and a larger contact area, significantly reducing the pressure per unit area and thus slowing down wear. Simultaneously, this invention includes a hollow push rod II with a threaded rod screwed into it. With unchanged oil pressure and starting height, this greatly increases the lifting height, broadening the application range of the jack. This utility model sets the second push rod as having openings at the top and bottom, and separates the threaded rod from the top plate, so that the threaded rod can be screwed in from the lower end of the second push rod first, and then the lower end of the second push rod can be sealed by a plug, and the top plate and the threaded rod are fixedly connected. Attached image description:
[0023] Figure 1 This is a perspective view of the present invention;
[0024] Figure 2 This is a cross-sectional view of the present invention.
[0025] Reference numerals in the attached drawings: 1. Base plate; 2. Hydraulic cylinder; 3. Push rod one; 4. Push rod two; 5. Plug; 6. Outer flange; 7. Inner flange; 8. Threaded rod; 9. Top plate; 10. Annular groove; 11. Mounting column; 12. Cross groove. Detailed implementation method:
[0026] The present invention will be further described below with reference to specific embodiments. See also: Figure 1 —2:
[0027] A jack includes a hydraulic cylinder 2 with its lower end fixedly mounted on a base plate 1. A hollow, open-top and open-bottomed push rod 3 is slidably mounted inside the hydraulic cylinder 2. A hollow, open-top and open-bottomed push rod 4 is slidably mounted inside the push rod 3. A plug 5 is sealed at the lower end of the push rod 4. An outer flange 6 protrudes outward from the lower end of the push rod 3 and the lower end of the plug 5. An inner flange 7 protrudes inward from the upper end of the push rod 3 and the upper end of the hydraulic cylinder 2. The inner flange 7 abuts against the corresponding outer flange 6 and is limited in position. A sealing ring 1 is fitted over the outer flange 6 and seals the gap between the outer side wall and the corresponding inner side wall of the outer flange 6. A threaded rod 8 is screwed into the push rod 4. A top plate 9 is fixedly mounted on the upper end of the threaded rod 8 above the push rod 4.
[0028] The working principle of this utility model is as follows: Figure 1 , 2 As shown, when the hydraulic cylinder 2 is pressurized, push rod 3 and push rod 4 rise slowly; when the pressure is released, push rod 3 and push rod 4 fall slowly. When it is necessary to further lengthen the jack, the threaded rod 8 can be rotated to unscrew it from push rod 4.
[0029] This invention features an outwardly protruding edge 6 at the lower end of the push rod 3 and the lower end of the plug 5, and an inwardly protruding edge 7 at the upper end of the push rod 3 and the upper end of the cylinder 2. The inner protruding edge 7 abuts against the corresponding outer protruding edge 6, providing upper limit positioning. A sealing ring is fitted over the outer protruding edge 6, sealing the gap between the outer wall of the outer protruding edge 6 and the corresponding inner wall. Both the outer wall of the outer protruding edge 6 and the corresponding inner wall, which are in contact with the sealing ring, are located inside and do not protrude to the outside, eliminating the problems of bumping, scratching, and wear / cutting of the sealing ring, effectively preventing hydraulic oil leakage. Furthermore, because the sealing ring is fitted over the outer protruding edge 6, compared to being fitted onto a slender push rod, the sealing ring 6 has a longer circumference and a larger contact area, significantly reducing the pressure per unit area and thus slowing down the wear rate. Meanwhile, this utility model features a hollow top rod 4, with a threaded rod 8 screwed into it. Under the condition of constant oil pressure and starting height, the lifting height can be greatly increased, thus broadening the application range of the jack. This utility model design makes the top rod 4 open at both ends and separates the threaded rod 8 from the top plate 9. This allows the threaded rod 8 to be screwed in from the lower end of the top rod 4 first, and then the lower end of the top rod 4 is sealed by a plug 5. The top plate 9 is then fixedly connected to the threaded rod 8.
[0030] To increase the lifting height, two or more push rods 3 are coaxially arranged and sequentially sleeved from the inside out. The outermost push rod 3's outer protruding edge 6 abuts and limits the inner protruding edge 7 of the cylinder 2. A sealing ring fitted outside the outermost push rod 3's outer protruding edge 6 seals the gap between the inner wall of the cylinder 2 and the outer wall of the outermost push rod 3's outer protruding edge 6. Adjacent push rods 3's outer protruding edges 6 and inner protruding edges 7 abut and limit the outer edges. The inner wall of the outermost push rod 3 and the outer wall of its adjacent inner push rod 3's outer protruding edge 6 are sealed by a sealing ring. The innermost push rod 3's inner protruding edge 7 abuts and limits the outer protruding edge 6 of the plug 5. A sealing ring fitted outside the plug 5's outer protruding edge 6 seals the gap between the inner wall of the innermost push rod 3 and the outer wall of the plug 5's outer protruding edge 6. In this embodiment, two push rods 3 are provided.
[0031] To prevent the inner push rod 3 from being completely pressed into the adjacent outer push rod 3, and the push rod 4 from being completely pressed into the push rod 3, a retaining spring is provided on the inner side of the lower end of the push rod 3. The retaining spring of the outer push rod 3 limits the lower position of the adjacent inner push rod 3, and the retaining spring of the innermost push rod 3 limits the lower position of the plug 5.
[0032] The installation structure of the plug 5 and the second push rod 4: The upper end of the plug 5 extends into the second push rod 4, and the upper end of the plug 5 is fixedly connected to the second push rod 4. The lower end face of the second push rod 4 abuts against the upper end face of the outer protruding edge 6 of the plug 5. The structure is simple, easy to install, and has a good sealing effect. In this embodiment, the upper end of the plug 5 is tightly connected to the second push rod 4.
[0033] During installation, first screw the threaded rod 8 into the second push rod 4 from below, and then tightly connect the upper end of the plug 5 to the second push rod 4 to seal the lower end of the second push rod 4.
[0034] Installation structure of sealing ring one: The outer side wall of the outer convex edge 6 is recessed to form an annular groove 10, and the sealing ring one is disposed in the annular groove 10.
[0035] For better sealing, each outer protruding edge 6 is provided with two or more annular grooves 10, and correspondingly, each outer protruding edge 6 is fitted with two or more sealing rings. In this embodiment, each outer protruding edge 6 is provided with two annular grooves 10, and correspondingly, each outer protruding edge 6 is fitted with two sealing rings.
[0036] To prevent the threaded rod 8 from completely unscrewing out of the top rod 4, a limiting structure is provided at the lower end of the threaded rod 8 to restrict its complete unscrewing out. The threaded rod 8 has a hollow structure, and a mounting post 11 extending into the threaded rod 8 is provided at the lower end of the top plate 9. The mounting post 11 is fixedly connected to the threaded rod 8. The structure is simple, easy to install, and the connection is firm and reliable. In this embodiment, the mounting post 11 is tightly fitted to the threaded rod 8.
[0037] In this embodiment, the limiting structure is used when the external thread of the threaded rod is not provided at the bottom of the threaded rod during machining.
[0038] During installation, the threaded rod 8 is screwed into the top rod 4 from the lower end and extends out from the upper end of the top rod 4. Then, the mounting post 11 of the top plate 9 is tightly connected to the threaded rod 8.
[0039] This utility model sets the threaded rod 8 as a hollow structure, which reduces the weight on the one hand, and makes it easier to screw the threaded rod 8 into the lower end of the top rod 4 and out the upper end of the top rod 4 during installation.
[0040] To facilitate finding the center of the jack during use, the top plate 9 is cylindrical, and the upper surface of the top plate 9 is recessed to form a cross groove 12, the center of which coincides with the center of the top plate 9.
[0041] To prevent the lifted object from sliding against the top plate 9 during use, the upper surface of the top plate 9 is provided with anti-slip protrusions.
[0042] The installation structure of the hydraulic cylinder 2: The lower end of the hydraulic cylinder 2 has an outward protrusion of the mounting flange 13. The base plate 1 is provided with a pressure plate 14 for pressing on the mounting flange 13. The bottom of the hydraulic cylinder 2 is provided with a sealing ring 2 to seal the gap between the hydraulic cylinder 2 and the base plate 1. The base plate 1 is provided with an oil passage connecting the inner cavity of the hydraulic cylinder 2 and the outside.
[0043] Furthermore, the lower surface of the hydraulic cylinder 2 is concave to form an annular groove for setting the sealing ring 2.
[0044] Furthermore, a gear pump is installed on the base plate 1, and the gear pump is connected to the inner cavity of the oil cylinder 2 through the oil circuit. An oil tank is provided on the base plate 1 surrounding the oil cylinder 2, and the oil tank is connected to the gear pump.
[0045] The above embodiments are only one of the preferred embodiments of this utility model and are not intended to limit the scope of implementation of this utility model. Therefore, all equivalent changes made in accordance with the shape, structure and principle of this utility model should be covered within the protection scope of this utility model.
Claims
1. A jack, characterized in that: The device includes a cylinder (2) with its lower end fixedly mounted on a base plate (1). A hollow push rod (3) with openings at the top and bottom is slidably mounted inside the cylinder (2). A hollow push rod (4) with openings at the top and bottom is slidably mounted inside the push rod (3). A plug (5) is sealed at the lower end of the push rod (4). An outer protrusion (6) protrudes outward from the lower end of the push rod (3) and the lower end of the plug (5). An inner protrusion (7) protrudes inward from the upper end of the push rod (3) and the upper end of the cylinder (2). The inner protrusion (7) abuts against the corresponding outer protrusion (6) and is limited in place. A sealing ring (1) is fitted on the outer side of the outer protrusion (6) and seals the gap between the outer side wall of the outer protrusion (6) and the corresponding inner side wall through the sealing ring (1). A threaded rod (8) is screwed into the push rod (4). A top plate (9) located above the push rod (4) is fixedly mounted on the upper end of the threaded rod (8).
2. The jack according to claim 1, characterized in that: Two or more push rods (3) are coaxially arranged and are sequentially sleeved from the inside to the outside. The outermost protruding edge (6) of the outermost push rod (3) abuts and limits the inner protruding edge (7) of the oil cylinder (2). The sealing ring sleeved outside the outermost protruding edge (6) of the outermost push rod (3) seals the gap between the inner wall of the oil cylinder (2) and the outer wall of the outermost protruding edge (6) of the outermost push rod (3); the outer protruding edge (6) and inner protruding edge (7) of two adjacent push rods (3) are respectively connected. 7) The inner wall of the outermost push rod (3) is sealed by a sealing ring; the inner edge (7) of the innermost push rod (3) is sealed by the outer edge (6) of the plug (5); the inner edge (7) of the innermost push rod (3) is sealed by the outer edge (6) of the plug (5); the sealing ring fitted outside the outer edge (6) of the plug (5) seals the gap between the inner wall of the innermost push rod (3) and the outer edge (6) of the plug (5).
3. The jack according to claim 1, characterized in that: The upper end of the plug (5) extends into the second push rod (4), and the upper end of the plug (5) is fixedly connected to the second push rod (4). The lower end face of the second push rod (4) abuts against the upper end face of the outer protrusion (6) of the plug (5).
4. A jack according to claim 1, characterized in that: The outer side wall of the protruding edge (6) is recessed to form an annular groove (10), and the sealing ring is disposed in the annular groove (10).
5. A jack according to claim 1, characterized in that: The lower end of the threaded rod (8) is provided with a limiting structure that restricts the threaded rod (8) from being completely screwed out of the top rod (4). The threaded rod (8) is a hollow structure. The lower end of the top plate (9) is provided with a mounting post (11) that extends into the threaded rod (8). The mounting post (11) is fixedly connected to the threaded rod (8).
6. A jack according to claim 1, characterized in that: The top plate (9) is cylindrical, and the upper surface of the top plate (9) is recessed to form a cross groove (12), the center of the cross groove (12) coincides with the center of the top plate (9).
7. A jack according to claim 1, characterized in that: The lower end of the cylinder (2) has an outward protrusion of an mounting flange (13). The base plate (1) is provided with a pressure plate (14) for pressing on the mounting flange (13). The bottom of the cylinder (2) is provided with a sealing ring II to seal the gap between the cylinder (2) and the base plate (1). The base plate (1) is provided with an oil passage connecting the inner cavity of the cylinder (2) and the outside.