A wire-wound starting resistor

Abstract

A wire-wound starting resistor of the present invention comprises a hollow shell and a resistor unit accommodated in the shell, the resistor unit comprises a support column, a plurality of support trays and a plurality of resistor strips, both ends of the support column are fixed to the shell, the support trays are insulated, the plurality of support trays are mounted on the support column in parallel, each resistor strip is in a spiral structure, the plurality of resistor strips are placed on the plurality of support trays respectively, the plurality of resistor strips are connected in series, the shell is filled with insulating paste so that the resistor unit is separated from the shell, and the resistor strip is coated with the insulating paste. Compared with the prior art, the wire-wound starting resistor of the present invention is fixedly packaged by the insulating paste, and the spiral resistor strip has no deformation space, so the installation of the resistor strip is firm and reliable, and the overall stability is high.

Description

Technical Field

[0001] The invention relates to the technical field of resistors, and in particular to a wire-wound starting resistor. Background Art

[0002] When the outdoor high-voltage power switch shunts current to the zero-voltage submodule capacitor, the power switch needs to be equipped with a starting resistor to prevent the starting current from being too large, causing the switch power supply to burn out the fuse or trip. High-power resistors are widely used in energy consumption control systems powered by variable-frequency motors, starting, speed regulation, and braking control systems for industrial motors, as well as simulated loads of various industrial electrical appliances and neutral point grounding resistors in distribution systems. The existing high-power resistors mainly include wire-wound resistors, thick-film resistors, and chip resistors. At present, it is difficult for high-power resistors to be both small in size and large enough in power requirements. With the development of science and technology, the higher the integration of power electronic equipment, the higher the requirements for the size of components. As an important component in electrical equipment, the performance, size, and power of resistors have a great influence on the stability of electrical and electronic equipment. To this end, the inventor invented a wire-wound resistor with patent numbers ZL201821584019.5 and ZL201821583986.X, which specifically discloses that the resistor bar passes through different side grooves of different cross support rods in a circuitous manner in sequence. The overall structure is relatively compact. When the volume of the box is constant, a longer resistor bar can be wound on the cross support rod to meet the needs of high-power use.

[0003] However, the resistor strip of the wire-wound resistor is easily separated from the side groove, resulting in short circuit between different sections of the resistor strip and damage to the entire resistor, and the stability is low. Summary of the invention

[0004] In view of the above technical problems in the prior art, the present invention provides a winding starting resistor with high stability.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A wire-wound starting resistor is provided, comprising a hollow shell and a resistor unit accommodated in the shell, wherein the resistor unit comprises a support column, a plurality of support trays and a plurality of resistor bars, both ends of the support column are fixed to the shell, the support trays are insulated, a plurality of the support trays are mounted on the support column in parallel, each of the resistor bars is in a spiral structure, a plurality of the resistor bars are placed on a plurality of the support trays respectively, and the plurality of the resistor bars are connected in series, and the shell is filled with insulating slurry to separate the resistor unit from the shell, and the resistor bars are covered by the insulating slurry.

[0007] Specifically, the resistor strips are spirally arranged on the same plane.

[0008] Alternatively, the resistor bar is spirally formed in a direction perpendicular to the support plate, and the spiral diameter gradually decreases in a direction away from the support plate, and the hardness of the resistor bar is sufficient to maintain the spiral posture.

[0009] Specifically, the winding starting resistor further includes a U-shaped conductive strip, and two adjacent resistor strips are connected in series via the conductive strip.

[0010] Specifically, the supporting tray is a circular thin plate.

[0011] Specifically, a mounting hole is opened in the middle of the support tray, the support column includes a plurality of insulating seats, a protrusion is provided on one side of the insulating seat, and a groove is provided on the other side of the insulating seat. The protrusion passes through the mounting hole of the support tray and is inserted into the groove of the adjacent insulating seat.

[0012] Specifically, the supporting tray is provided with a plurality of transition holes, and the plurality of transition holes are arranged around the mounting hole.

[0013] Specifically, a plurality of heat dissipation fins are integrally formed on the outer side of the shell, and the plurality of heat dissipation fins are arranged along the length direction of the shell.

[0014] Specifically, mounting brackets are provided at both ends of the housing, and the mounting brackets are provided with bolts. The bolts are inserted into the housing to be electrically connected to the resistor bar.

[0015] Beneficial effects of the present invention:

[0016] The wire-wound starting resistor of the present invention comprises a hollow shell and a resistor unit accommodated in the shell, the resistor unit comprises a support column, a plurality of support trays and a plurality of resistor strips, both ends of the support column are fixed to the shell, the support trays are insulated, the plurality of support trays are mounted on the support column in parallel, each resistor strip is in a spiral structure, the plurality of resistor strips are placed on the plurality of support trays respectively, the plurality of resistor strips are connected in series, the shell is filled with insulating paste so that the resistor unit is separated from the shell, and the resistor strip is coated with the insulating paste. Compared with the prior art, the wire-wound starting resistor of the present invention is fixedly packaged by the insulating paste, and the spiral resistor strip has no deformation space, so the installation of the resistor strip is firm and reliable, and the overall stability is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the structure of the winding starting resistor in the embodiment.

[0018] Figure 2 This is a schematic diagram of the structure of the winding starting resistor in the embodiment with the housing hidden.

[0019] Figure 3 for Figure 2 Magnified view at A in the middle.

[0020] Figure 4 Schematic diagram of the resistance bar of the wire-wound starting resistor in the embodiment.

[0021] Figure 5 Schematic diagram of a support tray for a winding starting resistor in an embodiment.

[0022] Figure 6 Schematic diagram of the insulating base of the winding starting resistor in the embodiment.

[0023] Reference numerals:

[0024] Shell 1, heat dissipation fins 11;

[0025] Resistor unit 2, tray 21, mounting hole 211, transition hole 212, insulating seat 22, protrusion 221, groove 222, conductive strip 23, resistor strip 24;

[0026] Install bracket 3 and bolt 4. DETAILED DESCRIPTION

[0027] The present invention is described in detail below in conjunction with specific embodiments and drawings.

[0028] The winding starting resistor of this embodiment is as follows Figures 1 to 3 As shown, it includes a hollow shell 1 and a resistor unit 2 accommodated in the shell 1, the resistor unit 2 includes a support column, a plurality of trays 21 and a plurality of resistor strips 24, combined with Figure 5 As shown, the tray 21 is a circular insulating mica sheet, and a mounting hole 211 is opened in the middle of the tray 21. The support column includes a plurality of Figure 6 The insulating seat 22 made of ceramic material shown in the figure has a protrusion 221 on one side of each insulating seat 22, and a groove 222 on the other side of the insulating seat 22. The protrusion 221 passes through the mounting hole 211 of the tray 21 and is inserted into the groove 222 of the adjacent insulating seat 22. In this way, multiple insulating seats 22 are inlaid to form a columnar support column. The two insulating seats 22 at both ends are fixed to the housing 1, and multiple trays 21 are installed in parallel on the support column. Each resistor bar 24 has a spiral structure, and multiple resistor bars 24 are placed on multiple trays 21 respectively, and the resistor bars 24 correspond to the trays 21 one by one. The winding start resistor also includes a U-shaped conductive bar 23, and two adjacent resistor bars 24 are connected in series through the conductive bar 23. The housing 1 is filled with an insulating slurry not shown in the figure, and the insulating slurry completely fills the interior of the housing 1, so that the resistor unit 2 is separated from the housing 1, and the resistor bar 24 is coated with the insulating slurry, and the resistor bar 24 is also firmly fixed on the tray 21 by the insulating slurry.

[0029] In this embodiment, the resistor bar 24 is as follows Figure 4As shown, the resistor bar 24 is spiraled on the same plane, which has the advantage that the resistor bar 24 is attached to the support tray 21, reducing the deformation of the spiral shape of the resistor bar 24 during the grouting process. In practice, the resistor bar 24 can be changed to spiral in a direction perpendicular to the support tray 21, and the spiral diameter gradually decreases in the direction away from the support tray 21. Such a resistor bar 24 has a higher hardness requirement, and the hardness of the resistor bar 24 is sufficient to maintain the spiral posture before grouting, and the insulating slurry cannot compress the spiral deformation of the resistor bar 24 during grouting. In order to reduce the influence of the slurry on the spiral shape of the resistor bar 24 during the grouting process, the support tray 21 is provided with a plurality of transition holes 212 evenly arranged around the mounting hole 211. During grouting, the slurry flows downward layer by layer through the transition holes 212, so that the slurry has a smaller squeezing force on the resistor bar 24. If there is no transition hole 212, the slurry can only flow inward from the circumference of the support tray 21, which requires an excessively large extrusion force for the slurry to flow to the insulating seat 22. This excessive extrusion force will compress the spiral deformation of the resistor bar 24, and even cause the distance between two adjacent circles of the resistor bar 24 to be too small or even to contact and short-circuit. As the number of support trays 21 and resistor bars 24 increases, the role of the transition hole 212 becomes more obvious, because the more insulating slurry is needed, the greater the extrusion force will be. The provision of the transition hole 212 solves this problem well.

[0030] In this embodiment, a plurality of heat dissipation fins 11 are integrally formed on the outer side of the housing 1 . The plurality of heat dissipation fins 11 are arranged along the length direction of the housing 1 . The housing 1 and the heat dissipation fins 11 are an integrated ceramic component.

[0031] In this embodiment, mounting brackets 3 are provided at both ends of the housing 1 , and the mounting brackets 3 are provided with bolts 4 . The bolts 4 are inserted into the housing 1 and electrically connected to the resistor bar 24 , and the bolts 4 serve as lead-out terminals.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A wire-wound starting resistor, characterized in that: The invention comprises a hollow shell and a resistor unit accommodated in the shell, wherein the resistor unit comprises a support column, a plurality of support trays and a plurality of resistor bars, both ends of the support column are fixed to the shell, the support tray is insulated, a plurality of the support trays are installed on the support column in parallel, each of the resistor bars is in a spiral structure, a plurality of the resistor bars are placed on a plurality of the support trays respectively, and the plurality of the resistor bars are connected in series, and the shell is filled with an insulating slurry so that the resistor unit is separated from the shell, and the resistor bars are covered by the insulating slurry; The resistor bar is spiraled in a direction perpendicular to the support tray, and the spiral diameter gradually decreases in a direction away from the support tray. The hardness of the resistor bar is sufficient to maintain the spiral posture.

2. A wire-wound starting resistor according to claim 1, characterized in that: The resistor strips are spirally arranged on the same plane.

3. A wire-wound starting resistor according to claim 1, characterized in that: The winding starting resistor also includes a U-shaped conductive strip, and two adjacent resistor strips are connected in series through the conductive strip.

4. A wire-wound starting resistor according to claim 1, characterized in that: The supporting tray is a circular thin plate.

5. A wire-wound starting resistor according to claim 4, characterized in that: A mounting hole is provided in the middle of the support tray, and the support column includes a plurality of insulating seats, a protrusion is provided on one side of the insulating seat, and a groove is provided on the other side of the insulating seat. The protrusion passes through the mounting hole of the support tray and is inserted into the groove of the adjacent insulating seat.

6. A wire-wound starting resistor according to claim 5, characterized in that: The supporting tray is provided with a plurality of transition holes, and the plurality of transition holes are arranged around the mounting hole.

7. A wire-wound starting resistor according to claim 1, characterized in that: A plurality of heat dissipation fins are integrally formed on the outer side of the shell, and the plurality of heat dissipation fins are arranged along the length direction of the shell.

8. A wire-wound starting resistor according to claim 1, characterized in that: Mounting brackets are provided at both ends of the shell, and the mounting brackets are provided with bolts. The bolts are inserted into the shell and electrically connected to the resistor bar.

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