DE8909259U1 - Alternator with stator core center lamella - Google Patents

Description

r · n ·

R.22826

2248/ot/wi/Zr
21.6.1983

Robert Bosch GmbH, 7000 Stuttgart, Germany

S Alternator with stator core center lamination ---ecY

State of the art

The invention is based on an alternating current generator according to the preamble of claim 1.i l Qi-'

In the case of alternating current generators and especially in the case of three-phase generators as alternators for motor vehicles etc., it is known (DE-OS 2 132 052) to design the stator core with a middle ring of larger diameter so that this ring forms an outer ring flange for clamping the stator core between the two bearing plates of the generator. This ring is preferably itself

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a part of the stator sheet;·;, thus formed from one or more stator sheet layers, which with their larger outer diameter form the outer ring shape for centering between the housing contact surfaces on both sides.

The stator center plates are made from one piece "N and are located between the two halves of the remaining stator package, with eyes in the form of projections, for example four eyes, preferably evenly distributed around the circumference of the center plates, being provided, which serve as support surfaces for the bearing shields of the generator. The entire stator package can then be riveted and/or welded together.

The eyes of the middle plates arranged around the circumference, which serve as centering for the two bearing halves of the generator housing, enable the three components A-bearing shield, B-bearing shield and ) of the stator package to be screwed together without the tightening forces of the screws passing through the eyes causing a deformation of the stator inner diameter. The two bearing shields in turn accommodate the bearings for the rotor shaft. In order to obtain a generator that is as quiet as possible, it is necessary, in addition to efforts in other areas, that the rotor is mounted exactly centrally to the stator. An important prerequisite for fulfilling this condition is that the middle plates of the stator package are aligned and placed between the remaining package halves in such a way that the coaxiality deviation between the outer and

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diameter of the middle lamellae and the inner diameter of the entire package is kept as small as possible. The middle lamellae must therefore always be designed so that their outer diameter can be aligned exactly concentrically with the inner diameter of the two remaining package halves.

/ The necessary degrees of freedom for this are obtained in the middle lamellas, which are necessarily one-piece for such an adjustment, by their inner diameter being slightly larger than that of the two adjacent stator package halves, in other words, the inner diameter of the middle lamellas is slightly smaller than the inner circle that accommodates the rotor. Furthermore, the groove surfaces, i.e. the free surfaces remaining between the webs of the lamellas, as well as the rivet hole diameters of the middle lamellas can be made larger, so that corresponding displacement options are available without this resulting in an overlap of the gaps created by the two

&ngr; Package halves free areas of the stator package.

It is therefore clear that the middle lamellae must be made in one piece and cannot, as is known for the lamellae forming the halves of the package, consist of individual segments that can be loosely inserted into the package. This is because, due to the larger inner diameter of the middle lamellae, these segments would otherwise move inwards during precise positioning, which is based on the outer diameter.

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However, one-piece slats are very material-intensive, i.e. they require a lot of raw material, as they have to be punched out of a solid disc at considerable expense.

It has therefore already become known elsewhere (DE-PS 2 015 502) to produce ring-shaped lamellae for electrodynamic machines by first starting from a flat sheet of ferromagnetic material and forming a tube from this sheet. This tube is then cut into corresponding tube pieces so that cylinders of predetermined dimensions and with a thickness corresponding to the initial sheet thickness are produced. Each tube piece is then bulged outwards between its end faces by a compression-deformation process and then pressed together to form a double-walled, ring-shaped disk by a force exerted in the axial direction. At the same time, when the bulged tube piece is pressed together, the inner and outer edges of the ring-shaped lamellae thus formed are calibrated. It is then still possible to separate the two lamellae that are created during each processing process by separating the compressed tube piece at the outer edge. The grooves are then machined into the ring-shaped lamella on the inner edge. This makes it possible to produce lamellas from one piece without the entire inner disc of the lamella ring being thrown away as waste during the otherwise necessary punching process, but it must be accepted that the compression process reduces the front surface areas of the original pipe section to a small extent.

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diameter and a middle layer of material must be made larger than the original pipe diameter, so that flow of the material is required or different materials

£ material thicknesses result.

The invention is based on the object of

for the stator package of an AC generator

s tors on the one hand material and thus cost saving under

To avoid punching out a round solid disc, but on the other hand to ensure that the central lamella is the required one-piece for positioning.

Advantage of the invention

The invention solves this problem with the characterizing features of claim 1fe» and has the decisive advantage that it is possible to punch individual segments for the middle slats out of a sheet metal strip in a material-saving manner and then to join the segments together to form a one-piece slat by pressing them together using appropriately designed joining elements.

The invention therefore combines the advantages of a one-piece slat in terms of handling during assembly with the material and cost-saving advantages of a slat consisting of segments, each of which is punched from individual sheet metal strips.

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The measures listed in the subclaims enable advantageous further developments and improvements of the design and manufacture of stator center plates in alternating current generators made possible by the invention. It is particularly advantageous to manufacture a center plate from several, for example two, three or four segments, whereby the division is carried out in such a way that the segments are as similar as possible.

The individual segments are then connected to form a one-piece full lamella using form-fitting fasteners at each end of the individual segment. For example, a circular attachment at the front end of one segment can be pressed into a corresponding recess at the adjacent front end of the other segment, thus connecting both segments to form a unit. This creates a type of buttoning which, when dimensioned accordingly, ensures a completely non-slip and rigid connection between the individual segments, so that the adjusting positioning of the middle lamella can also be safely controlled during assembly.

drawing

An embodiment of the invention is shown in the drawing and is explained in more detail in the following description. They show: Fig. i in longitudinal section the essential parts of a three-phase generator as an alternator

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for motor vehicles and the like as a preferred embodiment for the use of the present invention;

Fig. 2 in plan view a lamella segment for a

Central lamella according to the present invention in the form of a semicircular ring;

Fig. 3 a slat segment end area with recess for receiving the

Fig. 4 shown adjacent slat end area with protruding, circular attachment and

Fig. 5 shows a possible embodiment of a middle plate of a stator package consisting of two individual segments, pressed together by appropriately designed joining elements.

Description of the embodiments

The basic idea of the present invention is to produce the middle lamellae of a stator package by simply punching out partial segments from flat sheet metal strips and then positively connecting these segments to form a one-piece, rigid solid lamella.

In Fig. 1, which mainly serves to better understand the explanations of the state of the art given above and shows the arrangement of the middle plates in a three-phase generator as an alternator for motor vehicles and the like, the stator 1 is on the inner circumference of the two bearing plates forming the housing of the three-phase generator.

•&Igr;&idiagr; ■··· i · &igr; ·

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the A-bearing shield 8 and the B-bearing base 9, whereby the two bearing shields each accommodate the two-sided bearings 8a and 9a for the rotor shaft 10a of the rotor 10. In addition to the winding 2, the stator 1 comprises two package halves 3a and 3b, which accommodate the so-called middle lamellae between them, which are designated here as 4 and 5. The middle lamellae 4 and 5 are larger on their outer diameter 6 than the two package halves 3a and 3b and also have a predetermined number on their circumference, for example four eyes 7 (see also Fig. 5).

As already mentioned at the beginning, the inner diameter 13 of the middle lamellae is larger than the inner diameter 13' of the two package halves 3a and 3b, so that their outer diameter 6 can be aligned very precisely concentrically to the inner diameter 13' of the package halves during assembly, provided that the middle lamellae 4 and 5 react as a unit.

Fig. 2 shows a partial segment 12 punched from a flat sheet metal strip in a material-saving manner, whereby the number of segments that ultimately add up to a complete central lamella is not critical, so that a central lamella can also be made from several, for example two, three, four, five or even more segments. This also makes it possible to arrange the individual segments in a correspondingly favorable manner on the available sheet metal strips so that as little waste as possible is generated.

•I ■

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In order to form-fit the partial segments 12 with one another , so that the full circle of each central lamella can be formed, the segments have form-fit connecting means at their end regions 14 bsv» M' , which, according to a preferred embodiment, have a mutual locking effect and therefore connect the individual segments not only by force but also form-fit to form the full central lamella.

In the illustrated embodiment, a projection is formed on one end 14 of the lamella segment 12, which transitions from a tapered neck part 15 into a circular head part 16, whereby the other end 14' in the illustrated embodiment of the same lamella 12 then has a corresponding recess 17, which is formed from a partial circular shape 17a, which is open to the outside in the transition by projections on both sides. It is therefore possible to connect adjacent ends of lamella segments to one another and to connect all existing segments to form the unit of the complete central lamella by first placing the head part 16 and the opening 17a on top of one another and then pressing them together. The two end faces 14 and 14' of adjacent lamella segments support each other so that by pressing the circular projections into the corresponding recesses, the segments are rigidly and immovably connected to one another to form a unit, preferably in the manner of the "connection" shown in Figures 3 and 4.

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It is of course also possible to provide other, positive-locking connecting elements for the individual slat segments.

It is also possible to arrange only projecting lugs on one slat segment and only recesses on the other - however, the implementation form of slat segments shown in Figures 2, 3 and 4 is preferred, since in this way only one type of segment needs to be produced.

In any case, the respective slat segments of a predetermined number complement each other to form a one-piece and complete central slat 20, as shown in Fig. 5.

All features presented in the description, the following claims and the drawing can be essential to the invention both individually and in any combination with one another.

Claims (1)

R.22826 2248/ot/wi
21.6.1989 Robert Bosch GmbH, 7000 Stuttgart 10 EiTtnsprüche 1. Alternating current generator, in particular three-phase generator as an alternator for mobile units, motor vehicles, trains and the like, with a stator package and a rotor rotating in it, whereby a stator package central lamella with its outer diameter is accommodated by bearing plates forming the housing, characterized in that the central lamella (20) consists of individual, interconnected, segment-like parts (12). 2. Alternating current generator according to claim 1, characterized in that each central lamella is composed of a multiplicity of individual lamella segments (12) which have locking means (16, 17) on their adjoining end faces, with which they engage in a form-fitting manner. 3. Alternating current generator according to claim 1 or 2, characterized in that the locking means each consist of a circular, respectively projecting over the front end surface (I4) of each segment. i < 2248/ot/wi 21.6.1989 - 2 - R.22826 Head part (16) and a corresponding complementary recess (17) in the adjacent front end part of the adjacent lamella segment, whereby the head part is pressed into the recess and the gap-free opposite front end surfaces (14, 14') rigidly support the individual lamella segments against each other in the transition. 4. Alternating current generator according to one of claims 1 to 3, characterized in that each lamella segment has on its two end faces (14, 14*) the mutually complementary locking means (16, 17). nri &igr; i ir middle lamella of the Stator package of an alternating current generator, in particular three-phase generator as an alternator for mobile units, motor vehicles, trains and the like, wherein the stator package/with the outer diameter of its central lamella is received by two-sided bearing plates forming the housing of the alternating current generator, characterized in that individual partially circular lamella segments are punched out of a sheet metal strip and placed against one another with their respective end faces to form the one-piece central lamella and positively connected according to &Agr;&eegr; &pgr;&rgr;&Ggr; ¹¹ ^ ¹ ·* ^q r characterized in that the individual lamella segments on the flat sheet metal strip are material-spacing 2248/ot/wi 21.6.1989 - 3 - R-22826 liquid connection enabling mutual locking of the joining parts f at the front end faces of the lamella segments in ' complementary E^rm formed and interlocked / 2 i S~jl·. &iacgr;+&ogr;&kgr;£ ahaciyinacn claim ^r odor ^ thereby marked characterized in that the interlocking joints I parts recesses in the adjacent front end face &iacgr; chenbereich are projections that engage behind ' adjacent lamella segments in circumferential direction, whereby the adjacent end faces lie against one another and support one another.