Transformer bushing head assembly and transformer bushing

Abstract

The present invention discloses a head assembly of a transformer bushing, comprising an end cover and a cable connector; the end cover comprises an upper surface and a lower surface opposite to each other, a first through hole is arranged at the center of the end cover, a convex ring is arranged around the first through hole on the upper surface, and at least two grooves are arranged on the end surface of the convex ring; the cable connector passes through the first through hole, at least two pin holes are arranged on the cable connector, a pin passes through the groove and is fixed in the at least two pin holes, the pin is fixedly connected with the groove, so that the relative position of the cable connector and the convex ring is fixed. The present invention also discloses a transformer bushing, the head assembly of the transformer bushing is convenient for installation and disassembly, and can solve the problem of heating of the transformer bushing head.

Description

Technical Field

[0001] The present application relates to the technical field of power transmission insulation equipment, and in particular to a head assembly of a transformer bushing and a transformer bushing. Background Art

[0002] The power transformer is one of the most important and expensive key power equipment in the power system, and the transformer bushing is one of the key components of the transformer. The electrical performance of the transformer bushing directly affects the operating reliability and safety of the transformer.

[0003] At present, in the existing transformer bushing head, a cylindrical pin is mostly passed through the opening of the end cover to fix it with the cable connector, so that the cable connector is suspended in the conductive tube. There are the following problems: since the diameter of the opening is larger than the diameter of the cylindrical pin, there is a risk that the cable connector will jump up and down with the vibration of the transformer bushing, thereby causing discharge and causing heating of the head component; if the method of bending the pin is adopted, it is not convenient for the subsequent bushing to be disassembled, and when installing the bushing, the insertion pin needs to be aligned with the hole position, which is time-consuming, labor-intensive and inefficient. Summary of the invention

[0004] In view of the deficiencies in the prior art, one of the purposes of the present invention is to provide a head assembly of a transformer bushing, which is convenient for installation and disassembly and can solve the problem of heating of the transformer bushing head.

[0005] In order to achieve the above-mentioned invention object, the technical means adopted by the present invention are as follows: a head component of a transformer bushing includes an end cover and a cable connector; the end cover includes an upper surface and a lower surface relative to each other, a first through hole is arranged at the center of the end cover, a convex ring is arranged around the first through hole on the upper surface, and at least two grooves are arranged on the end surface of the convex ring; the cable connector passes through the first through hole, at least two pin holes are arranged on the cable connector, a pin passes through the groove and is fixed in the at least two pin holes, the pin is fixedly connected to the groove, so that the relative position of the cable connector and the convex ring is fixed.

[0006] Since the pin and the groove are fixedly connected to the transformer bushing head assembly, the relative position of the cable connector and the convex ring is fixed, so that the cable connector will not jump with the vibration of the transformer bushing, and the transformer bushing head will not generate heat due to unstable current; and the pin and the groove are fixedly connected, which is convenient for installation and disassembly, and is convenient for installation and maintenance.

[0007] Preferably, there are two pin holes, and the axes of the pin holes are on the same straight line; more preferably, the axes of the pin holes are located on the same diameter of the cable connector, which can achieve the best force balance and effectively reduce the difficulty of processing and matching.

[0008] Preferably, the two pin holes penetrate each other in the cable connector; only one pin shaft may be used, and the pin shaft directly penetrates the pin hole, so that the connection between the pin shaft and the cable connector is more convenient and reliable, and the force is more balanced.

[0009] Preferably, the groove is a U-shaped groove, and the end of the pin is a cylinder; the processing and matching of the U-shaped groove and the cylindrical pin are simpler.

[0010] Preferably, the pin protrudes from the end face of the convex ring; that is, the radial height of the pin end is greater than the depth of the groove, so that after the pin passes through the groove, the pin protrudes from the end face of the convex ring, and the pin can be fixed in the groove by pressing, providing a simple and reliable way to fix the pin.

[0011] More preferably, the head assembly also includes a wiring terminal, which is fixedly connected to the end cover, and the wiring terminal clamping pin forms a tight fit, which can further ensure that the relative position of the cable connector and the convex ring is fixed without shaking, thereby solving the problem of head heating.

[0012] Preferably, the terminal comprises a wiring portion, a receiving portion and a connecting portion, the receiving portion is provided with a stepped inner wall and a stepped surface, the stepped surface abuts the end surface of the convex ring, and the connecting portion abuts the upper surface; the shape of the inner wall of the terminal matches the shape of the cable connector so that it can be sleeved on the outer periphery of the cable connector and can be reliably connected.

[0013] Preferably, the accommodating portion is divided into a first accommodating portion and a second accommodating portion by a step surface, and a spring contact finger is arranged on the cable connector, the spring contact finger abuts against the inner wall of the first accommodating portion, so that the first accommodating portion is electrically connected to the cable connector; the second accommodating portion accommodates the convex ring; there is a stable electrical connection between the spring contact finger and the cable connector, which can maintain the equipotential of the head components and solve the problem of head heating.

[0014] In view of the deficiencies in the prior art, a second object of the present invention is to provide a transformer bushing which has a simple structure, is easy to install and disassemble, and does not have the problem of head heating.

[0015] The above-mentioned transformer bushing includes the above-mentioned head assembly.

[0016] Preferably, the transformer bushing also includes a conductive tube, the conductive tube fits the inner wall of the first through hole, and the cable connector is inserted into the conductive tube without contacting the conductive tube; the cable connector is suspended in the conductive tube, and there will be no electrical conduction and thus no unstable electrical connection, which will not cause heating of the transformer bushing head. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a cross-sectional view of a head assembly 100 according to a first embodiment of the present invention;

[0018] Figure 2is a three-dimensional schematic diagram of a head assembly 100 according to a first embodiment of the present invention;

[0019] Figure 3 is a cross-sectional view of a head assembly 200 according to a second embodiment of the present invention;

[0020] Figure 4 is a cross-sectional view of the connection terminal 203 of the second embodiment of the present invention;

[0021] Figure 5 is a partial cross-sectional view of a transformer bushing 1000 according to a third embodiment of the present invention;

[0022] Figure 6 1 is an overall schematic diagram of a transformer bushing 1000 according to a third embodiment of the present invention. DETAILED DESCRIPTION

[0023] Upon request, specific embodiments of the present invention will be disclosed herein. However, it should be understood that the embodiments disclosed herein are merely typical examples of the present invention, which may be embodied in various forms. Therefore, the specific details disclosed herein are not to be considered restrictive, but merely as a basis for the claims and as a representative basis for teaching those skilled in the art to apply the present invention in various ways in any appropriate manner in practice, including using the various features disclosed herein and in combination with features that may not be explicitly disclosed herein.

[0024] Embodiment 1:

[0025] like Figure 1-Figure 2 As shown, the present embodiment provides a head assembly 100 of a transformer bushing, the head assembly 100 comprising an end cover 101 and a cable connector 102; the end cover 101 comprises an upper surface 1011 and a lower surface 1012 relative to each other, a first through hole 1013 is arranged at the center of the end cover 101, a convex ring 1014 is arranged around the first through hole 1013 on the upper surface 1011, and the first through hole 1013 and the convex ring 1014 are arranged coaxially to facilitate later assembly; in the present embodiment, the inner diameter of the convex ring 1014 is equal to the diameter of the first through hole 1013, it can be understood that, in other embodiments, the inner diameter of the convex ring is not equal to the diameter of the first through hole, that is, the inner wall of the convex ring and the inner wall of the first through hole are not on the same curved surface.

[0026] In this embodiment, the cable connector 102 passes through the first through hole 1013, two grooves 1015 are provided on the end surface of the convex ring 1014, and two pin holes 1022 are provided on the cable connector 102. In other embodiments, the number of grooves on the end surface of the convex ring can be three, four or more, as long as corresponding pin holes are also provided on the cable connector, and the mechanical strength of the cable connector needs to be ensured at the same time.

[0027] In this embodiment, the pin 1021 passes through the groove 1015 and is fixed in the two pin holes 1022. The pin 1021 is fixedly connected to the groove 1015, so that the relative position of the cable connector 102 and the convex ring 1014 is fixed. In this embodiment, the pin 1021 is fixedly connected to the groove 1015, and can be glued, interference fit, etc., as long as it is easy to install and disassemble and does not cause permanent damage to components. The pin 1021 and the pin hole 1022 can be fixed by threaded fit, or the pin 1021 can be glued in the pin hole 1022. It can be understood that the arrangement of the pin 1021 and the groove 1015 in this embodiment changes the previous practice of drilling holes on the convex ring. Since the diameter of the hole in the convex ring is inevitably larger than the diameter of the pin end, a gap will be caused between the pin and the hole on the convex ring. When the entire transformer bushing vibrates, the cable connector connected to the convex ring through the pin will jump with the jumping of the pin, and the electrical connection between the cable connector and other components will be unstable, thereby causing heat release from the transformer bushing head; it also changes the previous practice of bending the pin on the basis of drilling a hole on the convex ring to prevent the cable connector from jumping. This method causes permanent damage to the pin, and subsequent disassembly and maintenance cannot be carried out after assembly is completed. Even if a problem is found in the assembly stage, the head component can only be completely replaced and scrapped to stop the loss in time, which increases the manufacturing cost and assembly risk.

[0028] In this embodiment, the number of pin holes 1022 is two, and the axes of the two pin holes 1022 are on the same straight line; further, the axes of the two pin holes 1022 are located on the same diameter of the cable connector 102, which can achieve the best force balance, and the processing difficulty and matching difficulty are low. In other embodiments, the axes of the two pin holes may not be on the same diameter of the cable connector, but the axes of the two pin holes can still be on the same straight line, that is, any straight line passing through the circumference of the convex ring. In other embodiments, the axes of the two pin holes can be at a certain angle to each other, as long as it is convenient to fix the pin in the cable connector.

[0029] In this embodiment, the two pin holes 1022 are mutually connected in the cable connector 102, which increases the installation margin of the pin 1021 and can adapt to pins 1021 of different lengths. In addition, in other implementations, a pin shaft can be used, and the pin shaft directly passes through the pin hole, so that the connection between the pin shaft and the cable connector is more reliable and the force is more balanced.

[0030] In this embodiment, the groove 1015 is a U-shaped groove, and the end of the pin 1021 is a cylinder; the processing and matching of the U-shaped groove and the cylindrical pin are more convenient. In other embodiments, the groove can be other shapes, such as rectangular, irregular shapes, etc., as long as it matches the shape of the pin end and has a high fixing strength, that is, the groove and the pin end are tightly matched without any movable gap.

[0031] In this embodiment, the cable connector 102 is located at one end of the lower surface 2012 of the end cover 201 and is provided with a connection hole, which can be connected to the cable.

[0032] In the head assembly 100 of the present embodiment, since the pin 1021 is fixedly connected to the groove 1015, the relative position of the cable connector 102 and the convex ring 1014 is fixed, so that the cable connector 102 will not jump due to the vibration of the transformer bushing, and the transformer bushing head will not generate heat due to unstable current; and the pin 1021 and the groove 1015 are fixedly connected, which is convenient for installation and disassembly, and is convenient for installation and maintenance.

[0033] Embodiment 2:

[0034] like Figure 3 As shown, this embodiment also provides another transformer bushing head assembly 200, which is different from the first embodiment in that the head assembly 200 further includes a terminal 203, and the terminal 203 is fixedly connected to the end cover 201. The terminal 203 is an electrical connection assembly of the transformer bushing and is used to electrically connect with other devices.

[0035] In this embodiment, the pin 2021 protrudes from the end surface of the protruding ring 2014; that is, the radial height of the end of the pin 2021 is greater than the depth of the groove. The pin 2021 can be fixed by pressing, providing a simple and reliable way to fix the pin 2021.

[0036] In this embodiment, specifically, the connection terminal 203 presses the pin 2021 to form a tight fit, which can further ensure that the relative position of the cable connector 202 and the convex ring 2014 is fixed without shaking, thereby solving the problem of head heating.

[0037] Combination Figure 4 As shown, in this embodiment, the terminal block 203 includes a wiring portion 2031, a receiving portion 2032 and a connecting portion 2033. The receiving portion 2032 is provided with a stepped inner wall and has a stepped surface 2037. The stepped surface 2037 abuts against the end surface of the convex ring 2014, and the connecting portion 2033 abuts against the upper surface 2011. The shape of the inner wall of the terminal block 203 matches the shape of the cable connector 202, so as to be sleeved around the cable connector 202. The connecting portion 2033 is fixedly connected to the end cover 201, and a fixed connection method such as screw connection or adhesive connection can be adopted. The inner wall of the terminal block 203 is pressed by the end surface of the convex ring 2014 and the pin 2022 to reliably fix the cable connector 202 and will not jump with the vibration of the transformer bushing. In other embodiments, the external shape of the terminal block can be in other forms, and the shape of its inner wall is sufficient, that is, the terminal block can press the pin and be fixedly connected to the end cover to achieve the purpose of fixing the relative position of the cable connector and the convex ring.

[0038] In this embodiment, a plurality of through holes 2034 are evenly arranged on the connection part 2033, a plurality of threaded holes corresponding to and matching the through holes 2034 are arranged on the upper surface 2011 of the end cover 201, and the end cover 201 and the connection part 2033 are fixedly connected by screws. The screw connection has a high strength, and the inner wall of the connection terminal 203 can be tightly pressed against the end surface of the convex ring 2014, without hindering the disassembly of the connection terminal 203. In other embodiments, the fixing method of the end cover and the connection part can also adopt other reliable connection methods such as bolt connection, or a mixed method of bolt connection and adhesive connection.

[0039] In this embodiment, the upper surface 2011 of the end cover 201 is provided with a sealing groove 2017, and a sealing ring (not shown in the figure) is provided between the end cover 201 and the connecting portion 2033, which can increase the sealing between the end cover 201 and the terminal 203. When the head assembly 200 is installed on the transformer bushing, oil leakage will not occur at the head assembly, thereby ensuring the sealing performance and electrical performance of the transformer bushing. In other embodiments, a sealing groove can also be provided where the connecting portion contacts the upper surface of the end cover, and a sealing ring is placed in the sealing groove. The technical effect is the same as above, and will not be repeated here.

[0040] In this embodiment, the accommodating portion 2032 is divided into a first accommodating portion 20321 and a second accommodating portion 20322 by a stepped surface 2037, and a spring contact finger 2023 is provided on the cable connector 202. Specifically, an annular groove is provided on the inner wall of the first accommodating portion 20321, and the spring contact finger 2023 is placed in the annular groove. The spring contact finger 2023 abuts against the inner wall of the first accommodating portion 20321, so that the first accommodating portion 20321 is electrically connected to the cable connector 202; the second accommodating portion 20322 accommodates the convex ring 2014; the spring contact finger 2023 and the cable connector 202 have a stable electrical connection, which can maintain the same potential of the head assembly 200 and solve the problem of head heating. In other embodiments, the annular groove may not be provided in the first accommodating portion, and there is a certain gap between the inner wall of the first accommodating portion and the cable connector, so that the spring contact finger can be pressed between the inner wall of the first accommodating portion and the cable connector, and the spring contact finger can also be kept in a relatively fixed state.

[0041] In this embodiment, the inner wall of the first through hole 2013 is also provided with an annular groove, and a sealing ring is arranged in the annular groove. When the head assembly 200 is installed on the transformer bushing, an additional seal of the head assembly is added to prevent oil leakage.

[0042] In the head assembly 200 of this embodiment, due to the setting of the terminal 203, the inner wall of the terminal 203 tightly fixes the pin 2021 and the groove 2015, and the relative position of the cable connector 202 and the convex ring 2014 is fixed, so that the cable connector 202 will not jump due to the vibration of the transformer bushing, and the head of the transformer bushing will not generate heat due to unstable current; and the pin 2021 is fixedly connected to the terminal 203 and the groove 2015 respectively, and is easy to install and disassemble, which is convenient for installation and maintenance.

[0043] Embodiment three:

[0044] like Figure 5-Figure 6 As shown, this embodiment is a transformer bushing 1000 , comprising the head assembly 200 .

[0045] In this embodiment, the transformer bushing 1000 further includes a conductive tube 300, which is attached to the inner wall of the first through hole 2013, and the cable connector 202 is inserted into the conductive tube 300 without contacting the conductive tube 300; the cable connector 202 is suspended in the conductive tube 300, and thus no electrical conduction occurs and thus no unstable electrical connection is generated, which will not cause the head of the transformer bushing 1000 to heat up.

[0046] In this embodiment, a sealing groove is provided between the conductive tube 300 and the inner wall of the first through hole 2013 to accommodate a sealing ring. An additional sealing arrangement can prevent oil leakage from occurring at the head of the transformer bushing.

[0047] In this embodiment, the transformer bushing 1000 also includes an oil conservator 400, a composite bushing 500, an oil-insulated tube 600, a terminal assembly 700 and a capacitor core, the head assembly 200 is connected to the oil conservator 400, and the conductive tube 300 is a part of the capacitor core.

[0048] In other embodiments, the transformer bushing may adopt the structure of the head assembly 100 described above.

[0049] Since the transformer bushing 1000 of this embodiment adopts the head assembly 200, the head of the transformer bushing will not generate heat due to unstable current, and it is easy to install and disassemble, and is convenient for installation and maintenance.

[0050] The technical content and technical features of the present invention have been disclosed above, but it is understood that under the creative ideas of the present invention, those skilled in the art can make various changes and improvements to the above structures and materials, including combinations of technical features disclosed or claimed separately herein, and obviously including other combinations of these features. These variations and / or combinations all fall within the technical field involved in the present invention and fall within the protection scope of the claims of the present invention.

Claims

1. A head assembly of a transformer bushing, characterized in that: The head assembly includes an end cap and a cable connector; The end cover comprises an upper surface and a lower surface opposite to each other, a first through hole is arranged at the center of the end cover, a convex ring is arranged around the first through hole on the upper surface, and at least two grooves are arranged on the end surface of the convex ring; The cable connector passes through the first through hole, and at least two pin holes are arranged on the cable connector. The pin passes through the groove and is fixed in the at least two pin holes. The radial height of the pin end is greater than the depth of the groove, so that the pin protrudes from the end surface of the convex ring. The pin is fixedly connected to the groove, so that the relative position of the cable connector and the convex ring is fixed.

2. The head assembly according to claim 1, characterized in that: The number of the pin holes is two, and the axes of the two pin holes are on the same straight line.

3. The head assembly according to claim 2, characterized in that: The two pin holes penetrate each other in the cable connector.

4. The head assembly according to claim 1, characterized in that: The groove is a U-shaped groove, and the end of the pin is a cylinder.

5. The head assembly according to claim 1, characterized in that: The head assembly also includes a wiring terminal, which is fixedly connected to the end cover and presses the pin.

6. The head assembly according to claim 5, characterized in that: The connection terminal comprises a connection portion, an accommodating portion and a connecting portion. The accommodating portion is provided with a stepped inner wall and has a stepped surface. The stepped surface abuts against the end surface of the convex ring. The connecting portion abuts against the upper surface.

7. The head assembly according to claim 6, characterized in that: The accommodating portion is divided into a first accommodating portion and a second accommodating portion by the step surface. The cable connector is provided with a spring contact finger, which abuts against an inner wall of the first accommodating portion to electrically connect the first accommodating portion to the cable connector. The second accommodating portion accommodates the convex ring.

8. A transformer bushing, characterized in that: Comprising the head assembly as described in claims 1-7.

9. The transformer bushing according to claim 8, characterized in that: The transformer bushing also includes a conductive tube, the conductive tube is in contact with the inner wall of the first through hole, and the cable connector is inserted into the conductive tube without contacting the conductive tube.

Images