Locomotive vehicle cable terminal

Abstract

The invention discloses a locomotive vehicle cable terminal which is characterized in that an oil storage device is designed to be communicated with an inner cavity of the cable terminal, the inner cavity of the cable terminal can be filled with polyisobutene through the oil storage device, and redundant swelling capacity is contained when the polyisobutene in the inner cavity of the cable terminal is heated; in addition, polyisobutene can be automatically supplemented to the upper part of the inner cavity of the cable terminal of the locomotive vehicle during horizontal transportation and installation of the cable terminal; oil leakage of the product is effectively prevented, partial discharge faults caused by air gaps are eliminated, the reliability of the product is improved, and the service life of the product is prolonged.

Description

Technical Field

[0001] The invention relates to a locomotive cable terminal and belongs to the technical field of electric locomotive operation and maintenance. Background Art

[0002] For the existing oil-filled cable terminals used in power systems, they are generally installed vertically, assembled and filled with polyisobutylene on site, and there is no horizontal transportation and installation. Therefore, only about two-thirds of the inner cavity needs to be filled with polyisobutylene, and the air gap at the top of the inner cavity can be used as a reserved space to accommodate the thermal expansion of polyisobutylene.

[0003] At present, the oil-filled cable terminals for electric locomotives are transported or installed horizontally during use, so the air gap in the inner cavity of the cable terminal needs to be completely filled with polyisobutylene. Otherwise, during horizontal transportation or installation, due to the effect of gravity, the polyisobutylene will cover the lower part of the inner cavity, and air gaps will appear in the upper part of the inner cavity, which will easily cause local discharge at the concentrated electric field, causing risks. However, if the inner cavity is completely filled with polyisobutylene, when the locomotive cable terminal is running, the polyisobutylene will expand due to heat, and there is a risk of oil leakage due to the expansion of the polyisobutylene due to heat. Therefore, it is urgent to provide a new technical solution to effectively prevent oil leakage of the product while eliminating local discharge failures caused by air gaps, thereby improving the reliability and service life of the product. Summary of the invention

[0004] The present invention aims to provide a locomotive vehicle cable terminal, which can prevent the oil leakage problem caused by the thermal expansion of polyisobutylene in the vehicle-mounted oil filling when the locomotive is running, and at the same time eliminate the risk of partial discharge during horizontal transportation or installation, thereby improving product reliability and service life.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a locomotive vehicle cable terminal, the cable terminal includes a cable terminal inner cavity, the cable terminal inner cavity is surrounded by the outer wall of the cable terminal head, the inner wall of the outer support insulator, the cable main insulation and the stress cone device; the cable terminal also includes an oil storage device, which is fixed to the upper part of the outer support insulator, and a through hole is provided in the middle of the oil storage device for passing through the cable terminal head. A filling hole is provided on the upper surface of the oil storage device for filling and exhausting liquid insulating filler. The oil storage device is also provided with an oil storage device inner cavity connected to the filling hole. An oil channel is provided in the oil storage device inner cavity for connecting the cable terminal inner cavity. The volume of the oil storage device inner cavity is larger than the volume of the cable terminal inner cavity that is not filled with oil flushed into the cable terminal when the cable terminal is in use when the cable terminal is placed horizontally.

[0006] The locomotive and rolling stock cable terminal provided by the present invention fully considers the actual operation conditions of the electric locomotive cable terminal and is an automatic replenishment device. When in horizontal transportation and installation, the locomotive and rolling stock cable terminal can replenish polyisobutene through the filling hole, automatically replenish the upper air gap in the inner cavity of the cable terminal, and the inner cavity of the oil storage device provides a storage space for the expansion amount when polyisobutene is heated, preventing product oil leakage and eliminating partial discharge faults caused by air gaps, and improving the reliability and service life of the product.

[0007] According to an embodiment of the present invention, the present invention can be further optimized, and the following is the technical solution formed after optimization:

[0008] In one preferred embodiment, the stress cone device includes a stress cone, and the stress cone is in direct and close contact with the inner wall of the outer support insulator.

[0009] The locomotive and rolling stock cable terminal provided by the present invention simplifies the product structure. The stress cone is in direct contact with polyisobutene and will not swell after experimental testing, reducing the composite interface and increasing the reliability of the product. Moreover, the stress cone is in direct and close contact with the inner wall of the outer support insulator, having a large contact pressure and playing a sealing role, increasing the insulation reliability of the interface.

[0010] In one preferred embodiment, the oil storage device is provided with mounting holes for fixing the oil storage device to the upper part of the outer support insulator, and the mounting holes penetrate through the inner cavity of the oil storage device in a sealed manner. The oil storage device provided by the present invention has a simple structure and is beneficial to the application in actual scenarios.

[0011] In one preferred embodiment, the cavity of the inner cavity of the oil storage device is a cylindrical structure. The cylindrical structure can improve the insulation of the product, is beneficial to the uniform distribution of the electric field, and avoids causing local field strength concentration.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: A locomotive and rolling stock cable terminal provided by the present invention is designed such that the oil storage device communicates with the inner cavity of the cable terminal. Polyisobutene can be filled into the inner cavity of the cable terminal through the oil storage device, and the excess expansion amount can be accommodated when the polyisobutene in the inner cavity of the cable terminal is heated. In addition, when the cable terminal is in horizontal transportation and installation, polyisobutene will be automatically replenished to the upper part of the inner cavity of the locomotive and rolling stock cable terminal, effectively preventing product oil leakage and eliminating partial discharge faults caused by air gaps, and improving the reliability and service life of the product. Description of the Drawings

[0013] Figure 1 is the structure diagram of the locomotive and rolling stock cable terminal of an embodiment of the present invention;

[0014] Figure 2Schematic diagram of a stress cone device according to an embodiment of the present invention;

[0015] Figure 3 Structural diagram of a locomotive and rolling stock cable terminal according to another embodiment of the present invention;

[0016] Figure 4 Cross-sectional view of an oil storage device of a locomotive and rolling stock cable terminal according to another embodiment of the present invention;

[0017] Figure 5 Top view of an oil storage device of a locomotive and rolling stock cable terminal according to another embodiment of the present invention.

[0018] Among them, 1 is a cable terminal head, 2 is an oil storage device, 3 is a bolt, 4 is an external support insulator, 5 is a closed air cavity, 6 is a cable copper core, 7 is a cable main insulation, 8 is a stress cone, 9 is an upper cover of the oil cavity, 10 is a lower cover of the oil cavity, 11 is a mounting hole, 12 is a welding, 13 is an oil channel, 14 is an inner cavity of the oil storage device, 15 is a filling hole, 16 is a through hole, 17 is a stress cone device, 18 is a cone support, and 19 is a stress cone cover. Detailed implementation mode

[0019] The present invention will be described in detail below with reference to the drawings and in combination with embodiments. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0020] Embodiment 1

[0021] The inner cavity of the locomotive and rolling stock cable terminal needs to be filled with polyisobutylene insulating liquid to fill the air gaps at the electric field concentration points, so as to prevent local discharge of the air gaps and reduce the reliability and service life of the product. Considering the possible horizontal transportation and installation of the cable terminal, the air gaps in the inner cavity of the cable terminal need to be completely filled with polyisobutylene. Otherwise, when installed horizontally, due to the action of gravity, the polyisobutylene will cover the lower part of the inner cavity, and air gaps will appear in the upper part of the inner cavity, and local discharge will occur at the electric field concentration points. When the locomotive and rolling stock cable terminal is operating, the polyisobutylene will expand when heated. To prevent the polyisobutylene from expanding and leaking oil when heated, Embodiment 1 of the present invention provides an oil storage device 2, as Figure 1 shown. The oil storage device 2 communicates with the inner cavity of the cable terminal. Through the oil storage device 2, polyisobutylene can be filled into the inner cavity of the cable terminal, and when the polyisobutylene in the inner cavity of the cable terminal is heated, it can accommodate the excess expansion amount. And when the cable terminal is horizontally transported or installed, the oil storage device 2 can supplement polyisobutylene and automatically fill it to the upper part of the inner cavity of the cable terminal.

[0022] The oil storage device 2 has a hollow structure with a through - hole in the middle for passing through the cable terminal head 1. It is fixed to the upper part of the outer support insulator 4 of the cable terminal through the mounting holes 11 on the periphery. A filling hole 15 that communicates with the internal cavity is provided on the upper surface of the oil storage device 2 for filling and exhausting polyisobutene. After the polyisobutene is filled and left to stand, the filling hole 15 is sealed. The inner cavity of the oil storage device is a non - fully sealed cavity, and there are notches on its inner cavity wall to keep the inner cavity of the oil storage device in communication with the inner cavity of the cable terminal, so that the polyisobutene in the two cavities can flow through each other. The diameter of the inner cavity of the oil storage device is larger than that of the inner cavity of the cable terminal. When installed horizontally, it automatically supplies polyisobutene to the inner cavity of the cable terminal, and the volume of the inner cavity of the oil storage device needs to be larger than the volume of the inner cavity of the cable terminal when the cable terminal is placed horizontally and not filled with oil in the unused state of the cable terminal, so as to reserve space for the expansion of polyisobutene.

[0023] Figure 2 It is a schematic structural diagram of the stress cone device 17. In this embodiment 1, the inner cavity of the cable terminal is composed of the inner wall of the outer support insulator 4, the cable main insulation 7, the outer wall of the cable terminal head 1, and the stress cone device 17. In this embodiment 1, the stress cone device 17 includes a stress cone cover 19, a stress cone 8, and a cone support 18.

[0024] Embodiment 2

[0025] As Figure 3 shown, in this embodiment 2, the cable terminal is in a vertical state. The cable copper core 6 and the cable main insulation 7 are processed into an integral structure. The cable terminal head 1 is crimped on the cable copper core 6 and becomes an integral part with the cable copper core 6. The stress cone 8 is sleeved on the cable main insulation 7 by an interference fit method. The cable terminal head 1, the cable copper core 6, the cable main insulation 7, and the stress cone 8 form an integral combined structure, passing through the inner cavity of the outer support insulator 4 and the inner hole of the oil storage device 2, constituting a closed air cavity 5 of the cable terminal composed of the inner wall of the outer support insulator 4, the cable main insulation 7, the stress cone 8, the outer wall of the cable terminal head 1, and the inner cavity 14 of the oil storage device. The closed air cavity 5 is filled with polyisobutene insulating liquid to assist in insulating the inside of the cable terminal. In this embodiment 2, the stress cone device 17 includes a stress cone 8 and a cone support 18. In this embodiment 2, the locomotive and rolling stock cable terminal simplifies the product structure. The stress cone 8 is in direct contact with polyisobutene and will not swell through test and measurement, reducing the composite interface and increasing the reliability of the product. Moreover, the stress cone 8 is in direct and close contact with the inner wall of the outer support insulator 4, having a large contact pressure, playing a sealing role and increasing the insulation reliability of the interface.

[0026] As Figure 4 shown, in this embodiment 2, the oil storage device 2 is formed by welding the upper oil chamber cover 9 and the lower oil chamber cover 10 into one body. As Figure 5As shown in the figure, in this embodiment, the oil storage device 2 is installed on the upper part of the outer support insulator 4 through six bolts 3. Two G3 / 8 threaded holes are provided on the upper cover 9 of the oil chamber for the filling and exhaust of polyisobutene. After the polyisobutene is filled and left standing, it is sealed with a matching G3 / 8 copper pipe plug. After the polyisobutene is filled into the oil storage device 2, it will flow into the closed air chamber 5 through the oil passage 13. In this embodiment 2, the hollow inner cavity formed by the upper cover 9 and the lower cover 10 of the oil chamber is the inner cavity 14 of the oil storage device. Its volume and the radially elongated cylindrical structure are specially designed. The cylindrical structure can improve the insulation of the product, is conducive to the uniform distribution of the electric field, and avoids causing local field strength concentration. By using the oil storage device 2 of this embodiment, the polyisobutene can fill the volume of the inner cavity of the cable terminal, automatically fill the upper air gap of the inner cavity of the cable terminal. When the upper air gap of the inner cavity of the cable terminal is filled with polyisobutene, there is still space in the inner cavity of the oil storage device as a reserved expansion space.

[0027] The content clarified in the above embodiments should be understood that these embodiments are only used to more clearly illustrate the present invention, rather than to limit the scope of the present invention. After reading the present invention, various equivalent forms of modification of this embodiment by those skilled in the art all fall within the scope defined by the appended claims of the present invention.

Claims

1. A cable terminal for locomotive vehicles, characterized in that, The cable terminal includes a cable terminal inner cavity, which is surrounded by the outer wall of the cable terminal head (1), the inner wall of the outer support insulator (4), the main cable insulation (7), and the stress cone device (17). The cable terminal further includes an oil storage device (2), which is fixed to the upper part of the outer support insulator (4). A through hole (16) is provided in the middle of the oil storage device (2) for passing through the cable terminal head (1). A filling hole (15) is provided on the upper surface of the oil storage device (2) for filling and exhausting the liquid insulating filler. The oil storage device (2) also has an oil storage device inner cavity (14) connected to the filling hole (15). An oil channel (13) is provided in the oil storage device inner cavity (14) for communicating with the cable terminal inner cavity. The volume of the oil storage device inner cavity (14) is larger than the volume of the cable terminal inner cavity that is not filled with oil when the cable terminal is placed horizontally in the unused state of the cable terminal.

2. The cable terminal for rolling stock according to claim 1, characterized in that, The stress cone device (17) includes a stress cone (8), and the stress cone (8) is in direct and close contact with the inner wall of the outer support insulator (4).

3. The locomotive and rolling stock cable terminal according to claim 1, characterized in that, The oil storage device (2) is provided with a mounting hole (11) for fixing the oil storage device (2) to the upper part of the outer support insulator (4), and the mounting hole (11) passes through the oil storage device inner cavity (14) in a sealed manner.

4. The locomotive and rolling stock cable terminal according to claim 1, characterized in that The cavity of the oil storage device inner cavity (14) is of a cylindrical structure.

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