DE7306596U - Electric machine with pronounced poles, especially DC machine - Google Patents

Description

SIEMENS AKTIENGESELLSCHAFT :. . ·

VPA 73/3707 GM

Electric machine with pronounced poles, especially DC machines

innovation
The present Ss & k & dagng = relates to an electrical machine with pronounced poles, in particular a direct current machine, the excitation winding of which consists of individual winding-insulated, disc-shaped coils, the flat conductors of which are wound flat-edged, and the spacers located directly beneath the pole core separated, are pushed over the insulated pole core that they lie essentially in a plane extending perpendicular to the side walls of the pole core.

■ Such an electrical machine with pronounced poles and an excitation winding made of disc-shaped coils is described in DL-PS 13 081. In this known machine the disc-shaped coils of the excitation winding consist of several flat-edged layers one on top of the other ;. (Coiled flat conductors that are twist-insulated against one another. In addition, each coil has overall external insulation surround, which hold the individual conductors together and thus gives the coil a certain mechanical strength. the disk-shaped coils are arranged on the Pclkern of the salient poles in each case one below the other by spacers separated, which lay directly next to the pole core gen and extend v / eit over the coil surface. In addition, in the middle of the pole core, which are divisible is provided as holding elements steel plates.

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As the height of the spacers and the disc-shaped holding devices are small compared to the height of the disc-shaped coils of the excitation winding, they are located in the space which is given by the height of the pole core, relatively close to each other. But this gives bad conditions for the heat transfer from the flat conductor to the surrounding air, since the exposed parts of the disc-shaped coils, the are not covered by the spacers, only form a small part of the total surface. In addition, the Heat also penetrate the relatively strong outer insulation of the coils. This means that the cross sections the flat conductors must be chosen so large that a relatively low excess temperature when operating the machine occurs.

In order to dissipate the heat generated in the excitation winding as well as possible, so that a lot of power can be accommodated in a small space v / ground is already known from DT-Gbm 1 817 5 ^ 7, to impregnate the coils of the excitation winding with a hardenable compound and then to harden it. This will make everyone the Avoid the formation of cavities that prevent heat transfer and also lie on top of one another in several layers between the flat edges wound flat conductors still arranged cooling plates that protrude from the coil insulation and from Flow of cooling air in the pole gap washes around v / ground.

innovation

The present Ep € = i = ¥ id «sg = is based on the task through a different construction of the coils of the excitation winding with simple means a good heat transfer with less space requirement to achieve. To solve this problem, in an electrical machine of the type described in the introduction According to the invention, each disc-shaped coil has only one layer. wraps and soaked and hardened with a hardenable compound, and without additional holding devices there is only a small fraction of the coil surface area between the coils overlapping insulating spacers arranged.

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Due to the single-layer design of each disc-shaped coil of the excitation winding, these are very flat and their largest Projection is in each case in a plane extending perpendicular to the walls of the pole core. Furthermore, the flat discs by impregnating them with a hardenable compound and subsequently hardening the winding insulation so great internal strength that they can be used as a self-supporting component. This means that special holding devices can be used be waived. Therefore, the ones arranged directly next to the pole core have only a small one A fraction of the coil surface covering spacers essentially only have the task of connecting the coils to one another and to keep a distance from the yoke and pole piece for the purpose of insulation, since the disc-shaped coils are only winding-insulated are. An external insulation of the coils is omitted and thus also an additional thermal resistance, because the winding insulation is much thinner than an outer insulation. Thus, the heat can unhindered, not even by holding devices, over the large, exposed, heat-emitting surface of the flat panes to the outside air or to the cooling air flow that flows through the pole gaps. This good cooling of the coils enables the flat conductors to be subjected to high thermal loads and allows high copper losses in the coil without the coil exceeding the permissible limit heating. The copper requirement and thus the space requirement for a certain power is therefore smaller than with an excitation coil of the known type only a small pole height, which reduces the machine outer diameter compared to machines with exciter poles of the known type is reduced. This still means an essential one Cost savings.

Another advantage is that the excitation winding is in each case composed of several individual coils, which can be connected in series or in parallel, which is a good one

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Allows adaptation to required pathogen data. You can therefore use different excitation powers from identically structured, but received differently switched coils. As a result, the number of excitation coils to be dimensioned differently is reduced for different machine designs.

Since the spacers have no supporting function for the excitation coils exercise, it is advisable to only provide them in the better-ventilated pole gaps in the case of rectangular coils and not on the ends of the poles.

This can also improve the heat transfer further be achieved that the winding insulation is arranged only between the individual flat conductors, so that the The end faces of the disc-shaped coils remain f: tei, that is to say bare metal or only a thin layer of the hardened one Impregnating agent are coated.

innovation

In the following, the statement is based on the figures in the figures

1 and 2 illustrated embodiments explained in more detail. The figures each show a radial section in the scheme through the pole of an electrical DC machine with excitation coils designed according to the invention.

In an electrical direct current machine, the excitation winding 2 arranged on each main pole 1 consists of each two flat disc-shaped coils 3 which are electrically connected to each other. Any flat, disc-shaped coil is a single layer of flat-edged wound, wound with a suitable, impregnable insulating material for winding insulation Flat conductors 4 constructed. Each coil 3 is coated with a curable impregnating resin such as. B. an epoxy resin-acid anhydride hardener mixture soaked and then cured. This creates a firm bond between the coiled Flat conductors 4 one below the other, so that each coil 3 is a self-supporting Bai5element forms.

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The flat disc-shaped coils 3 are devoid of any holding device are pushed over the pole core 6 of the main poles 1, which is surrounded by an insulation 5, and are interconnected »As well as to the pole piece 7 and the yoke 8 kept at a distance. Spacers 9, which are in the immediate vicinity of the pole core 6, are used for this purpose. These spacers 9 are in the rest only arranged in the pole gap 10 and not on the end faces of the main roll 1. The coils 3 have the same as the main poles 1 and their pole core 6 have a rectangular cross-section.

Since the excitation coils 3 lie essentially in a plane extending perpendicular to the side walls 11 of the pole core 6, the height of the main poles 1 can be kept very small in each case. This results in a reduction in the outside diameter of the machine and thus a substantial saving in costs. In addition, the space requirement of the coils 3 of the excitation winding 2 designed according to the invention is less than that for coils of the known type, v / eil the flat disc-shaped excitation coils 3 have a large heat-emitting surface on v / iron, around which the cooling air flow in the pole gaps flows on all sides. As a result, the thermal load on the flat conductors 4 of the coils 3 can be selected to be very high, so that the copper requirement for a certain excitation power and thus in turn the space requirement for the coils 3 of the excitation winding 2 is less than with excitation coils of the conventional type.

Fig. 2 shows a different arrangement of the coils 3 of the field winding 2. This is recommended for the case ₁ that the field winding 2 must have a large number of turns. In this case, the coils 3 are arranged in pairs and are kept at a distance from one another and from the pole piece 7 and yoke 8 by spacers 9. Despite this arrangement of the excitation coils 3 in pairs, one is still sufficient

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r; roßo würmenbgebcndo surface of the coils 3 available, the direct from the cooling air flowing in the Pollückc 10 is washed around.

Are the coils 3 to further improve the 'heat transfer provided with a turn insulation, which is only between the individual turns of the flat conductor 4 is arranged and leaves the end faces of the coils 3 free, so must be in pairs arranged coils 3 zv / ischen the abutting end faces in each case an insulation can be provided which however, it can be relatively thin, v / eil it corresponds to only one turn insulation.

In this embodiment too, the field winding 2 is off Single-layer wound coils 3 of flat conductors 4 arranged in pairs / in pairs, the space requirement in the radial direction is relative low, so that the height of the main poles 1 can be kept small.

2 figures
4 claims

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Claims (4)

• · * Φ φ r * 0 frr «l ^ t ro ····« t · VPA 73/3707 GM protection claims 1st Electrical machine with pronounced poles, in particular a DC machine, the excitation winding of which consists of individual winding-insulated, disc-shaped coils, the flat conductors of which are wound flat-edged, and which, separated from one another by spacers immediately next to the pole core, are pushed over the insulated pole core in such a way that they are essentially lie in a plane extending perpendicular to the side walls of the pole core, characterized in that each disc-shaped coil (3) is wound only in one layer and soaked and cured with a hardenable mass, and that without additional holding devices between the coils (3) only a small one A fraction of the coil surface covering insulating spacers (9) are arranged. 2. Electrical machine according to claim 1, characterized in that in the case of rectangular coils (3) the spacers (9) only lie in the pole gap (10). 3. Electrical machine according to claim 1 or 2, characterized characterized in that the disc-shaped coils (3) are each arranged in pairs and kept at a distance. 4. Electrical machine according to claim 1 or 2, characterized in that the winding insulation only between the individual turns of the flat conductor (4) is arranged and the surfaces of the coils (3) leaves free.