JPS604588B2 - Electrical capacitor with pot-shaped metal casing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The invention has a cylindrical winding, the gap between the housing and the winding preferably being at least partially filled with an insulating liquid, and an upper and a lower insulation. A pot having a conductive coating on the end face of a wound body that is insulated from the casing by a cap and held in the casing in the direction of the casing via a casing recess, and whose closed end face is closed by an insulating material lid. The present invention relates to an electrical capacitor having a shaped metal casing.

Capacitors of this kind are already known (German Published Patent Application No. 2 350 272), in which the capacitor winding is fixed by a hard holding plate to prevent it from swinging.
This holding plate presses in the axial direction the capacitor winding which is electrically insulated by the insulating cap through the recessed part of the casing.

Impregnation of the capacitor is ensured by holes in the winding retaining ring. Via this hole the impregnating liquid can enter the interior of the casing. This known structure has the following drawbacks. This means that on the one hand a very high pressing force in the axial direction of the winding is required to hold the capacitor winding against deflection inside the casing, and on the other hand a winding retaining ring as an additional component. The insertion of the capacitor requires additional construction, which increases costs and requires additional steps during capacitor assembly. The object of the invention is to provide a capacitor of the type mentioned at the outset, which avoids the above-mentioned disadvantages.

This problem can be solved according to the present invention by providing at least one protrusion on the inside of the upper and lower insulating caps so that the protrusion prevents the insulating cap from being manipulated and maintains a distance from the end face of the adjacent winding body. is solved by forming a passage in the insulating cap between the intermediate chambers not filled by the turns in the casing. The electrical capacitor according to the invention has the following advantages over known capacitors.

This means that the additional part can prevent the winding from being manipulated on the one hand, while on the other hand, due to the hollow space between the winding and the upper insulating cap, sufficient free space is maintained for the passage of the liquid impregnating material. be done. This simplifies the construction both in terms of material consumption as well as in terms of the various assembly steps, and increases the operational reliability of the capacitor. Operational reliability is improved both mechanically and electrically. Mechanically, damage due to short circuits or connecting conductors being penetrated into the capacitor winding is excluded; electrically, flawless and complete impregnation and specified filling of the entire capacitor winding are guaranteed. be done. According to the present invention, the capacitor winding can be fixed without any knots by fixing the protrusion existing on the capacitor winding between the insulating caps, such as the solder protrusion at the fixing point of the connecting conductor. It is particularly advantageous to use it to keep it free of debris, as it is simple and economical to implement.

Next, the present invention will be explained in detail using the drawings.

FIG. 1 shows the casing of an electric capacitor. The entire capacitor has a cylindrical or pot-like shape and is made of metallic material, preferably aluminum.
The bottom of the casing is indicated at 11. The upper closed part of the casing is closed by a lid 12. This lid is held between the flanged edge of the outer wall of the casing on the one hand and the recess 13 on the other hand. Further recesses are indicated at 15, which are used for elongation and for cutting the tear conductor 14. The broken conductor 14 forms an electrical connection to the lower wound plain contact strip of the capacitor winding 16. The upper connecting bridge of the capacitor winding is connected via a connecting conductor 17 to an outer connecting lug 18 . The break conductor 14 is connected to a connecting lug 19. The connecting conductor 17 is fixed to the bridging piece of the upper winding body using solder 20.
It will be held in A torn conductor 14 is electrically and mechanically fixed to the solder 21 of the lower winding body bridging piece. Insulation between the capacitor winding 16 and the casing 10 is achieved using an upper insulating cap 22 and a lower insulating cap 23. FIG. 2 is a sectional view showing the internal structure of the casing bottom surface 11.

The bottom surface has a rib 24 extending in a star shape. FIG. 3 is a sectional view thereof. The individual ribs 24 are offset from each other by 150 degrees in the exemplary embodiment, and the thread angle of the ribs is 600 degrees in the illustrated example. The ribs are formed during the manufacture of the aluminum casing in a flow press process together with all other forming steps. FIG. 4 clearly shows the configuration of the lower insulating cap.

In the right-hand part of the figure, a rib 25 is shown which is provided on the outside of the longitudinally extending part of the cap. This rib facilitates the insertion of the cap into the casing. Piston effects causing air leakage are avoided. The outer surface of the lower insulation cap 23, which rests on the casing bottom 11, has a roughened bottom surface 26 to increase the coefficient of friction between the insulation cap and the bottom 11.

FIG. 5 shows a plan view of the lower insulating cap 23, with the inner radially extending ribs 27 clearly visible.

Engaged between these are solder points 21 which form projections on the lower conductive coating on the lower end face of the winding 16. The shape of the ribs 27 is shown on an enlarged scale in FIG. 6, corresponding to the section W-- in FIG. The ribs extend in the radial direction only over a partial area of the bottom of the insulating cap 23, since the transmission of force must take place only in the area of the solder 21. FIG. 7 is a plan view of the inner surface of the upper insulating cap 22. FIG.

This cap is likewise formed with essentially radially extending lips 28 . These ribs 28 engage the upper solder 20' of the conductive coating on the end face of the upper winding body when the capacitor is assembled and completed, and thus prevent the windings from eroding into the insulating cap 22. Make it. FIG. 8 is a cross-sectional view of the upper insulating cap 22, the shape being shown in the axial direction. Insulation cap 22
It has a protrusion 29 for determining the center of the winding body 16 in the central region of the cap, and the green portion of the cap covers the winding body 16 by three rivers. The outer side of the upper insulating cap 22 is roughened in the region that serves as the abutment for the elongated recess 15, so that the coefficient of friction is increased in this region as well, so that the emplacement is strengthened and the winding body 16 is tightened against the casing. I try not to change it for just one river. The area with the outer roughened surface of the upper insulating cap 22 is indicated at 31. From the sectional view of FIG. 9, it can be seen that three edge grooves 32 are provided.

These grooves play an important role in the impregnation of capacitors, for example. These grooves facilitate the passage of the impregnating liquid. This will be explained in detail later. 10 and 11 are enlarged views of the side edge area of the upper insulating cap 22. FIG.

FIG. 10 shows an enlarged view of the groove 32, and FIG. 11 shows that instead of a straight groove, a radial groove 32' can be formed. 1st
The functions of the two forms according to Figures 0 and 11 are the same,
In both cases it is achieved to construct channels through which the soaking material passes. The method according to the invention is advantageously used in electrical capacitors in which the gap between the housing and the winding is at least partially filled with an insulating liquid. Forming grooves 32, 32' and 33 in the upper insulating cap creates an impregnated channel between the conductive coating of the winding-like surface and the insulating cap, which provides rapid, complete and A given impregnation is guaranteed. As the insulating cap, a synthetic resin is used which is chemically stable to the impregnated material and has a high degree of mechanical strength. In the assembled state, the block consisting of the capacitor winding 16 and the insulating caps 22 and 23 is pressed by the elongated recess 15 into the housing bottom 11 .

The positive and partially frictional assembly ensures that the capacitor winding 16 does not sink into the housing 10 even under high rotational and vibrational stresses. The star-shaped ribs 24 on the inner surface of the casing bottom 11 of the aluminum casing 10 to be flow pressed are connected to the lower insulating cap 23 made of polyamide.
is placed on the phased bottom 26 of the. This cap also supports star-shaped ribs 27, which engage the solder points 21 mentioned above, so that the casing 101
This vibration of the wound body 16 is eliminated. This rubbing is ensured by additionally engaging the upper solder 20 with the inner groove 33 of the upper insulating cap 22, which is fixedly pressed against the winding body 16 by the recessed part 15 after assembly. is further reinforced. Upper insulation cap 2
2 and the groove 15 is ensured by facing the outer surface of the upper cap 22.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view of the capacitor of the present invention, Figure 2 is a cross-sectional view of the capacitor in Figure 1 excluding the winding body and lower cap, and Figure 3 is a cross-sectional view along the line of Figure 2. 4 is a partially cutaway schematic diagram of the lower insulating cap, and FIG. 5 is a plan view of the insulating cap in FIG. 4 as seen from the direction of arrow V. 6 is a partial sectional view taken along the line 1 in FIG. 5, FIG. 7 is a plan view of the upper insulating cap viewed from the direction of arrow W in FIG. 8, and FIG. 8 is a partial sectional view taken along the line 1 in FIG. 9 is a sectional view taken along line KK in FIG. 7, FIG. 10 is an enlarged partial plan view of FIG. 7, and FIG. 11 is a partial plan view of FIG. 7. This is a phantom enlarged view. 10, 11...Casing, 13, 15...Groove, 16.
...Wound body, 20, 21...Protrusion part, 2
2, 23... Insulation cap, 24, 27, 28
...Protrusion, 26...Rough surface. Fi9.1 Fi9.2 Fi. 3Fig. Fig.5 Fig9.6 Fig. 7Fig. 8 Fi9.9 Fi9.10 Fig. 11

Claims (1)

[Scope of Claims] 1. A cylindrical winding body, the gap between the casing and the winding body being at least partially filled with an insulating liquid, and an upper and a lower insulating cap insulating the winding body with respect to the casing. electrical conductor having an urn-shaped metal casing with a conductive coating on the end face of the winding which is axially held in the casing through a casing recess and whose open end face is closed by an insulating lid; In the capacitor, at least one protrusion 27, 28 is provided on the inside of the upper and lower insulating caps 22, 23, and a gap is provided between the end faces of adjacent windings so that the protrusion does not twist the insulating caps 22, 23. The winding 16 is held in the casing 10 at the upper insulating cap 22.
A capacitor characterized in that a passage is formed between hollow chambers which are not filled by. 2. The capacitor according to claim 1, wherein at least one protrusion 20 is formed on the end face of the upper winding body, and the protrusion holds the winding body 16 on the inner surface of the upper insulating cap 22 so as not to twist it. 3. The capacitor of claim 1, wherein the outer surface of the upper insulating cap 22 has a high coefficient of friction. 4. A capacitor according to claim 1, wherein the bottom of the casings (10, 11) is provided with a protrusion (24) on the inner surface thereof, which protrusion (24) is adjacent to a roughened surface (26) of the lower surface of the lower insulating cap (23). 5 The inside of the lower insulating cap 23 is connected to the protrusion 27 and/or
or has a recessed part, and at least one protrusion 21 on the end surface of the lower winding body is engaged with the recessed part.
Capacitors listed. 6 Projection 2 on the upper and/or lower end surface of the winding body
3. The capacitor according to claim 2, wherein 0 and 21 are made of solder. 7 The inner surface of the upper insulating cap 22 and/or the inner surface of the lower insulating cap 23 and/or the casing 11
2. A capacitor according to claim 1, wherein the protrusions on the bottom-inner surface of the capacitor extend radially. 8. The capacitor according to claim 1, wherein the insulating caps 22, 23 are made of synthetic resin. 9 The block consisting of the insulating cap of the upper part 22 and lower part 23 and the capacitor winding body 16 is inserted into the recessed part 15 for extension.
2. A capacitor according to claim 1, supported by and pressed against the casing bottom.