A sealing ring for unbonded steel strand

Abstract

This utility model relates to a sealing ring for unbonded steel strand. The sealing ring body, including an elastic sealing ring body, an inner protruding C-shaped sealing surface, a lip, and an end face, all constitute sealing structural elements. The cross-section of the elastic sealing ring body is an inwardly protruding C-shaped structure, and the outer side of the sealing ring body has an annular groove. The elastic sealing ring body is divided into lip portions at both ends and an arc-shaped sealing surface portion in the middle, with the end face portion located between the lip portions and the arc-shaped sealing surface portion. The sealing ring can be used not only for sealing cylindrical surfaces but is also particularly suitable for sealing many irregular quasi-cylindrical surfaces. For example, the outer contour shape of the unbonded steel strand HDPE sheath being sealed is close to a hexagonal spiral prism with rounded corners, rather than a cylindrical surface. Therefore, a good conformal fit effect is required for the sealing element, and this utility model effectively meets this requirement.

Description

Technical Field

[0001] This utility model relates to the field of sealing technology for prestressed engineering, specifically a sealing ring for unbonded steel strands, which is particularly suitable for sealing and protecting external prestressed anchors, anchor cables, and unbonded steel strand stay cables in projects such as bridges and prestressed concrete wind power towers. Background Technology

[0002] Currently, among the products used in engineering fields such as bridges and prestressed concrete wind power towers, such as external prestressed anchorages, anchor cables, and unbonded steel strand stay cables, the sealing elements for unbonded steel strands mainly include the following types, such as perforated rubber sheets, rectangular cross-section sealing rings, or sealing rings, dust rings, and sealants used in hydraulic and pneumatic applications. The above sealing elements are more suitable for sealing circular structures.

[0003] like Figure 3 As shown, the unbonded steel strand consists of a steel strand body 201 made of multiple high-strength steel wires twisted together, an anti-corrosion grease covering the steel strand body, and a protective jacket 202 tightly wrapped around the anti-corrosion grease. The outer contour of the sealed unbonded steel strand protective jacket is close to a hexagonal spiral prism with rounded corners, rather than a cylindrical surface (the steel strand shown in the figure is not part of this invention; the illustration is provided primarily to illustrate the principles and ideas of this invention). Because the above-mentioned sealing elements are more suitable for sealing products with circular sealing surfaces, current sealing elements have certain problems with the sealing reliability and durability of unbonded steel strands due to limitations in the sealing structure principle. Using the above-mentioned sealing structure often results in stress corrosion of the steel strand due to sealing structure failure, leading to premature replacement of the steel strand or anchor cable, and consequently, significant economic losses.

[0004] This invention addresses existing problems by studying engineering characteristics and needs, the features of the steel strand to be sealed, and the sealing principle, and thus specifically invented this sealing ring. Utility Model Content

[0005] The purpose of this utility model is to provide a sealing ring for unbonded steel strands that adapts to the irregular cylindrical outer contour of the unbonded steel strand sheath and is suitable for a wide range of outer diameter dimensions of the unbonded steel strand sheath. Therefore, this sealing ring has a good sealing effect, strong versatility, simple structure, is easy to promote, has a high cost performance, and is easy to maintain.

[0006] The technical solution of this utility model:

[0007] A sealing ring for unbonded steel strand includes an elastic sealing ring body. The cross-section of the elastic sealing ring body is a C-shaped structure protruding inward. The outer side of the sealing ring body has an annular groove. The elastic sealing ring body is divided into lip portions at both ends and an arc-shaped sealing surface portion in the middle. The end face portion is located between the lip portions and the arc-shaped sealing surface portion.

[0008] The beneficial effects of this utility model are:

[0009] 1. The sealing ring of this utility model can not only be used for sealing cylindrical surfaces, but is especially suitable for sealing many irregular cylindrical surfaces. For example, the outer contour shape of the unbonded steel strand HDPE sheath being sealed is close to a hexagonal spiral prism with rounded corners, rather than a cylindrical surface. Therefore, the sealing element is required to have a good conformal fit, and this utility model meets this requirement very well.

[0010] 2. In existing technologies, the outer contour dimensions of the sealed unbonded steel strand HDPE sheath are not fixed. Taking unbonded steel strands with diameters of Φ15.2 and Φ15.7 as examples, considering the differences in steel strand diameter tolerances, sheath wall thickness tolerances, and grease content, the outer contour dimensions of the sheath for these specifications of unbonded steel strands can range from Φ17.2 to Φ20.5 in actual engineering applications. This range is relatively large, approaching 19.2%. It is difficult to meet such a wide range of sealing versatility requirements using commonly used sealing elements in existing technologies. This invention solves this problem, making its industrial application and promotion much easier. In other words, the sealing element of this invention demonstrates excellent versatility and practicality.

[0011] 3. In the sealing structure of the anchor and the steel strand in this application, the inner side of the sealing ring is sealed with the outer protective sleeve of the unbonded steel strand, the outer side is sealed with the anchor plate, and the upper and lower sides are sealed with the anchor plate and the pressure plate respectively. This structural design makes the sealing effect between the anchor and the unbonded steel strand better. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of the sealing ring structure for the unbonded steel strand in this application.

[0014] Figure 2 This is a schematic diagram of the sealing structure between the anchor and the steel strand in this application.

[0015] Figure 3 This is a schematic diagram of an unbonded steel strand structure.

[0016] Figure label:

[0017] Figure 1 Middle: Elastic sealing ring body 1;

[0018] The sealing ring structure includes: lip 101; arc-shaped sealing surface 102; end face 103; and annular groove 104.

[0019] Figure 2 In the middle: 1. Sealing ring; 2. Unbonded steel strand; 3. Anchor plate; 4. Pressure plate; 5. Screw;

[0020] The anchor plate has a tapered anchor hole 301; the sealing ring has an arc-shaped sealing surface 102.

[0021] 203 is the outer contour surface of the unbonded steel strand sheath; 204 is the end face of the unbonded steel strand sheath.

[0022] Figure 3 In the middle: steel strand 201; unbonded steel strand sheath 202. Detailed Implementation

[0023] To address the problems in the background art, this application presents a sealing ring for unbonded steel strands, primarily used for sealing unbonded steel strands. Its engineering applications mainly include external prestressed anchorages, anchor cables, and unbonded steel strand stay cables used in bridges, prestressed concrete wind turbine towers, and other similar projects. Its function is to prevent external moisture from entering the anchorage and to prevent grease and other substances inside the anchorage from leaking out.

[0024] It should be noted that in the description of this application, terms such as "inner", "outer", "upper", and "lower" that indicate direction or positional relationship are based on the direction or positional relationship shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this application.

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] A sealing ring for unbonded steel strand includes an elastic sealing ring body 1. The cross-section of the elastic sealing ring body 1 is a C-shaped structure protruding inwards. The outer side of the sealing ring body 1 has an annular groove 104, which is divided into two lip portions 101 at both ends and an arc-shaped sealing surface 102 in the middle. Between the lip portion 101 and the arc-shaped sealing surface 102 is an end face 103. The included angle between the two end faces 103 of the elastic sealing ring body 1 is β, where 0°≤β≤45°. The elastic sealing ring body 1 is made of rubber. The elastic sealing ring body is an overall annular structure, with the inwardly protruding C-shaped sealing surface, lips, and end faces forming a sealing structure. The inwardly protruding arc-shaped sealing surface contacts the HDPE sheath of the unbonded steel strand to seal the unbonded steel strand; its end face and lips each form a separate sealing structure for contact with the sealing elements of the anchor plate and pressure plate of the anchor, thus forming a complete sealing structure. The presence of the annular groove on the outer side of the sealing ring allows it to be significantly compressed. This enables the sealing ring of this invention to not only better adapt to the outer contour characteristics of the unbonded steel strand HDPE sheath but also to accommodate dimensional fluctuations in the HDPE sheath's outer contour. This also facilitates its widespread industrial application and broad applicability. The steel strand body of the unbonded steel strand passes through the sealing ring, and the outer contour surface 203 of the protective outer jacket contacts and seals the arc-shaped sealing surface 102 of the sealing ring.

[0027] The sealing structure of this application, which combines a sealing ring with an anchor and an unbonded steel strand, includes an anchor, an unbonded steel strand 2, and a sealing ring 1. The anchor includes an anchor plate 3 and a pressure plate 4, which are connected by screws 5. The sealing ring is the sealing ring 1 described above. The anchor plate 3 has an anchor hole 301 for the steel strand to pass through. The end of the anchor plate 3 near the pressure plate 4 has a sealing groove. The sealing ring 1 is placed in the sealing groove and is pressed tightly by the anchor plate 3 and the pressure plate 4, so that the upper and lower end faces 103 of the sealing ring are in tight sealing contact with the anchor plate 3 and the pressure plate 4, respectively. The steel strand 2 passes through the anchor hole 301. The inner side of the sealing ring 1 is in tight contact with the outer contour surface 203 of the protective jacket of the unbonded steel strand 2 to achieve a seal. The outer lip 101 of the sealing ring 1 is in tight sealing contact with the sealing groove.

[0028] The sealing ring works within the anchor plate as follows: The sealing ring is located within the sealing groove, and the pressure plate presses it tightly. The lip and end face seal against the anchor plate and pressure plate. The C-shaped arc surface of the sealing ring tightly fits against the outer contour surface of the PE sheath of the steel strand, forming a seal against the unbonded steel strand. For unbonded steel strands with different outer diameters of the PE sheath, the degree of compression of the groove space varies; however, in existing technologies, the compression of rubber entities without annular grooves is limited. This is one of the important measures to adapt to changes in the sheath's outer diameter. The same principle can be applied to sealing unbonded steel strands of other diameters.

[0029] Specific examples of sealing rings for unbonded steel strands:

[0030] Example 1:

[0031] Technical parameters of the sealing ring: outer diameter Φ26mm, inner diameter Φ16.9mm, sealing ring height 9mm, and included angle β=45° between the two end faces.

[0032] Applicable unbonded steel strand sizes: for sealing unbonded steel strands with diameters of Φ15.2~15.7.

[0033] Installation steps: After the anchor is assembled, push the unbonded steel strand into the anchor hole. The steel strand body passes through the anchor hole. The PE sheath of the unbonded steel strand radially expands the sealing ring in the sealing groove and makes it in close contact with the sealing ring. The outer side and the upper and lower sides of the sealing ring are in close contact with the anchor plate and the pressure plate at the same time.

[0034] Example 2:

[0035] Technical parameters of the sealing ring: outer diameter Φ22mm, inner diameter Φ14.4mm, sealing ring height 8mm, and included angle β=37° between the two end faces.

[0036] Applicable unbonded steel strand size: For sealing Φ12.7 unbonded steel strand.

[0037] Installation steps: After the anchor is assembled, push the unbonded steel strand into the anchor hole. The steel strand body passes through the anchor hole. The PE sheath of the unbonded steel strand radially expands the sealing ring in the sealing groove and makes it in close contact with the sealing ring. The outer side and the upper and lower sides of the sealing ring are in close contact with the anchor plate and the pressure plate at the same time.

[0038] Example 3:

[0039] Technical parameters of the sealing ring: outer diameter Φ26mm, inner diameter Φ16.8mm, sealing ring height 8mm, and the included angle β=0° between the two end faces, that is, the two end faces of the sealing ring are parallel.

[0040] Applicable unbonded steel strand sizes: for sealing unbonded steel strands with diameters of Φ15.2~15.7.

[0041] Installation steps: After the anchor is assembled, push the unbonded steel strand into the anchor hole. The steel strand body passes through the anchor hole. The PE sheath of the unbonded steel strand radially expands the sealing ring in the sealing groove and makes it in close contact with the sealing ring. The outer side and the upper and lower sides of the sealing ring are in close contact with the anchor plate and the pressure plate at the same time.

[0042] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art, inspired by this description, design similar structures and implementations to the above embodiments without departing from the technical essence of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A sealing ring for unbonded steel strand, characterized by: The elastic sealing ring body is in a C-shaped structure with an inward convex cross section, has an annular groove on the outer side, and is divided into lip portions at both ends and an arc-shaped sealing surface portion in the middle.

2. A sealing ring for adhesive-free steel strand according to claim 1, characterized in that: The two end face portions of the elastic sealing ring body have an included angle β, and 0°≤β≤45°.

3. A sealing ring for adhesive-free steel strand according to claim 1, characterized in that: The material of the elastic sealing ring body is rubber material.

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