HK1083565B - Insulant housing comprising an inner ribbed contour - Google Patents

Description

Insulating material housing with internal rib profile

The invention relates to an insulating material housing for receiving and insulating electrically charged components in a tubular and integral and dimensionally stable housing having a circumferentially closed cross section and being penetrated by at least one through-opening for receiving a voltage-loadable connecting element, wherein ribs for increasing the resistance to leakage currents are formed on the housing.

Such an insulating material housing is disclosed, for example, in german patent application publication DE 19712182 a 1. The disclosed insulating material housing is made of casting resin and is used to accommodate and insulate a vacuum circuit breaker. The vacuum interrupter is disposed within a tubular enclosure. The housing extends beyond the vacuum interrupter tube by a hollow-cylindrical shoulder section. A through hole for accommodating a connecting piece is arranged on the side wall of the shoulder section. The connection piece enables the vacuum interrupter to be easily brought into contact with the current lead. In order to increase the resistance to leakage currents, the shoulder section has ribs extending in a closed manner around the shoulder section between its passage opening and an opening of the housing facing away from the vacuum interrupter. These ribs are formed on the outside of the shoulder section.

A disadvantage of the above-described known insulating material housing is that the ribs do not increase the strength against leakage currents. In contrast, a leakage current can flow along the inside of the casing to the grounded component without bypassing the ribs. Therefore, the intensity of the leakage current resistance is determined by the length of the shoulder section. In order to meet the respective strength requirements with respect to leakage currents, the shoulder portion therefore needs to be designed correspondingly longer. However, this leads to a construction which disturbs the space, which is generally undesirable.

German patent application publication DE 3538955 a1 discloses an insulating material housing for a compressed gas switch, wherein a tubular housing defines a gas chamber for extinguishing an arc formed between two switch contacts. The tubular casing is provided with an inner groove and an outer groove, and a through hole for arc extinguishing gas to flow is formed at the intersection point of the inner groove and the outer groove. These inner and outer grooves serve to enhance the mechanical stability of the casing.

A motor is described in german patent document DE 3712226C 2. The laminated core is provided with a winding and is provided with an inner groove for reducing the leakage current distance.

German patent DE 3923205 discloses an electrical junction box. It can be seen that through holes and rib segments are provided in the planar area of the terminal block. The rib segments surround the through holes from the sides.

DE 2740371 a1 discloses a tubular jacket with longitudinally extending ribs for improved heat dissipation.

German patent publication DE 19503347 a1 discloses a vacuum switch with a tubular casing, wherein the casing has on its inner side inner ribs which are closed around.

German patent document DE 3145391C 2 discloses a pressurized gas switch with an insulator. Wherein the switch is provided with annular gas-conducting chambers and with lamellae extending in the longitudinal direction.

The object of the present invention is to provide an insulating material housing of the type mentioned in the introduction which has a compact construction and is easy and therefore inexpensive to manufacture.

The object is achieved according to the invention by an insulating housing for receiving and insulating an electrically charged component, comprising a tubular and one-piece, dimensionally stable jacket which has a circumferentially closed cross section and is penetrated by at least one through-opening for receiving a voltage-loadable connecting element, wherein ribs for increasing the resistance to leakage currents are formed on the jacket, and according to the invention the ribs are designed as rib segments which surround each through-opening from several sides, the rib segments having longitudinal ribs which extend in each case in the longitudinal direction of the jacket and which are connected in a transition to at least one transverse rib which extends perpendicularly to the longitudinal direction and in the transverse direction of the jacket.

According to the invention, it is possible to dispense with the provision of ribs which extend in a closed manner over the entire circumference of the annular tubular jacket, so that no leakage currents follow the direction of extension of the ribs into the regions of the jacket which are free of ribs and thus bypass the ribs in a manner which shortens the leakage path. This applies to both the inner and outer ribs. Thus, the relevant profiled portion of the rib can be confined around the through hole. By limiting the through-opening from several sides by rib segments, the leakage current is forced to flow via a ribbed region, wherein the leakage path is increased according to the invention. It is not necessary here for the rib segment to extend in a closed manner around the through-opening. The rib segment can therefore surround the through-opening from three sides only. In this case, however, it is ensured that the path which the leakage current has to travel to bypass the rib segments is greater than the straight path of the leakage current which flows directly to the component having the different potential. The straight path is also referred to as an air line.

In other words, the rib segments have rib segments which are connected to one another and extend over an arc angle of 0 to 180 °, for example 60 to 120 ° or preferably 90 °.

The jacket is made according to the invention of a dimensionally stable or rigid material. This prevents the jacket from being made of an elastic material which could escape from an inner core after or during its production due to elastic deformation of the material. As a material for producing such a dimensionally stable insulating housing, it is possible to use epoxy resins, such as potting resins or other thermosetting or thermoplastic materials.

The rib segments have longitudinal ribs extending in the longitudinal direction of the casing, respectively, which are connected to at least one transverse rib extending perpendicularly to the longitudinal direction and in the transverse direction of the casing. The rib segments thus formed can be produced particularly simply, so that the production costs of the insulating material housing are further reduced.

According to a suitable development of the invention, the rib segments are arranged on the inside of the casing.

In a further development of the invention, the transverse ribs are not closed around their circumference when viewed in a cross-sectional view of the housing. A core for forming the integral structure for forming the inner ribs can therefore be removed without difficulty during production after the insulating material casing has hardened.

In a further embodiment of the invention, the longitudinal ribs each have a longitudinal rib height such that, as seen in a cross-sectional view of the housing, the longitudinal ribs and the transverse ribs lie against a common surface contour. The longitudinal ribs and the transverse ribs thus together define a cavity through which electrical components can be introduced into or removed from the insulating material housing. The longitudinal ribs and the transverse ribs are therefore arranged approximately flush with one another and jointly abut against the contour of the available cavity. In other words, the leakage path is optimized in the longitudinal and transverse directions over an available cavity. This is because it is avoided that the height of the ribs is lower than necessary for introducing the predetermined component.

It is also advantageous if the common surface contour is a circular contour. This allows, for example, a cylindrical vacuum switch to be inserted into or removed from the insulating material housing.

Further developments and advantages of the invention are explained in more detail below with reference to the drawing, wherein corresponding components are denoted by the same reference numerals in the figures. In the drawings:

FIG. 1 is a longitudinal cross-sectional view of one embodiment of an insulation enclosure according to the present invention;

FIG. 2 is a cross-sectional view of the insulation jacket of FIG. 1 taken along section line II;

fig. 3 is a cross-sectional view of the insulative material housing of fig. 1 taken in longitudinal section along another cross-sectional line.

Fig. 1 shows a longitudinal section through an embodiment of an insulating material housing 1 according to the invention. The insulating material casing 1 has a jacket 2 made of casting resin and a plurality of outer ribs 3 and inner ribs 4 respectively molded on the jacket 2. The insulating material housing is thus of one-piece construction.

A cylindrical vacuum interrupter 5 is visible in the insulating material housing, wherein an elastic material is provided between the casing 2 and the vacuum interrupter 5 in order to compensate for temperature-induced volume changes of the vacuum interrupter 5 during operation.

The vacuum interrupter 5 has a stationary contact and a movable contact controlled in movement in relation thereto in its interior. Only the free end of a switching rod 7, which is fixedly connected to the movable contact, is visible in fig. 1. The switching lever can transmit the drive movement of a drive unit, not shown, to the movable contact. For the transmission of the drive movement from the drive unit to the switching lever 7, transmission elements are provided, such as levers, push rods or the like, which are not shown in fig. 1 for the sake of clarity of the illustration. In order to electrically connect the switching rod 7 to the movable contact, a strip conductor 8 having bending elasticity is provided. The strip conductor 8 is fixed on one side to the switching rod 7 which is moved in a controlled straight line and on the other side to a fixed-position connecting piece 9. The coupling piece 9 is arranged in a through hole 10 of the casing 2 and has a threaded coupling hole 11. A connecting line, not shown in the figures, can be fixed by means of the connecting opening 11.

As can also be seen from fig. 1, the insulating-material housing 1 is formed in a tubular or hollow-cylindrical shape, wherein the inner ribs have both longitudinal ribs 12 extending in the longitudinal direction of the jacket 2 and transverse ribs 13 extending perpendicularly thereto. Wherein the longitudinal ribs 12 are connected to the transverse ribs 13 at transition points 14. This forms a rib segment which surrounds the through-opening 10 on three sides. A potential leakage current is thus forced to flow from the connection 9 through the rib segments to the opening 15 of the casing 2. A leakage path which first runs along the first longitudinal rib 12 closest to the through-opening 10, then transversely through the other two longitudinal ribs 12 and finally through the unformed or unformed region to the free opening 15 may be longer than the path from the connection 9 down to the free opening 15 via the transverse rib 13. Therefore, the strength against the leakage current is ensured by the molding depth of the inner rib or the outer rib 3.

Fig. 2 is a cross-sectional view of the insulating material casing shown in fig. 1, taken along section line II. From this figure, only the inner ribs 4 are visible, and it is clear that the longitudinal ribs 12 have different rib heights, so that they lie together with the transverse ribs 13 on a common surface contour in the cross-sectional illustration. The surface contour is here a reference circle. In other words, all the longitudinal ribs 12 are arranged flush with the transverse ribs. The reference circle defined by said longitudinal ribs 12 and transverse ribs 13 is a semi-circle complementary to the other semi-circle defined by the inner surface of the casing 2. These two semi-circles constitute the full circle 16 shown in fig. 2. The full circle 16 represents the cross-section of a cavity. The cavity is configured in a cylindrical shape, the inner diameter of which is larger than the outer diameter of the vacuum interrupter 5. This prevents the vacuum circuit breaker 5 from being disturbed by the casing 2 or the insulating material housing 1 even when it is replaced after the start of operation. The leakage current is therefore optimized over a predefined cavity.

Fig. 3 is a cross-sectional view of the insulative material housing of fig. 1 taken in longitudinal section along another cross-sectional line. It is clear from this figure that the through-opening 10 is surrounded on multiple sides by the rib segments, namely the longitudinal ribs 12 and the transverse ribs 13.

Claims (5)

1. An insulating material housing (1) for receiving and insulating an electrically charged component (5), comprising a tubular and one-piece construction and dimensionally stable housing (2), the housing (2) has a circumferentially closed cross section and is penetrated by at least one through-opening (10) for receiving a voltage-loadable connecting element (9), wherein ribs (12, 13) for increasing the resistance to leakage currents are formed on the jacket (2), characterized in that the ribs (12, 13) are designed as rib segments which surround each through-opening (10) from several sides, the rib segments (12, 13) have longitudinal ribs (12) extending in the longitudinal direction of the casing (2), the longitudinal ribs (12) are connected in transition to at least one transverse rib (13) extending perpendicularly to the longitudinal direction and in the transverse direction of the casing (2).

2. An insulating-material casing according to claim 1, characterised in that each transverse rib (13) extends circumferentially without closure in a cross-sectional view of the casing (2).

3. An insulating-material casing according to claim 1 or 2, characterised in that the rib segments (12, 13) are arranged inside the casing (2).

4. An insulating-material casing according to claim 3, characterised in that the longitudinal ribs (12) each have a longitudinal rib height such that, seen in a cross-sectional view of the casing (2), the longitudinal ribs (12) and the transverse ribs (13) bear against a common surface contour (16).

5. An enclosure of insulating material according to claim 4, characterised in that the common surface contour (16) is a reference circle.