Patent Application
20200373803
This application claims priority under 35 USC 119 to German Patent Appl. No. 10 2019 113 785.3 filed on May 23, 2019, the entire disclosure of which is incorporated herein by reference.
The invention relates to a stator of an electric machine, having a stator lamination stack that comprises stator laminations, and having at least one stator winding that comprises conductor bars arranged in slots of the stator lamination stack and fixed in the slots of the stator lamination stack with the aid of a fixing device. The invention also relates to a method for producing and/or machining a clamping stator lamination for such a stator.
U.S. Pat. No. 4,994,700 discloses a dynamoelectric machine having a stator with a stator main body and at least one winding. The winding comprises conductor bars arranged in slots of the main body. Each bar is fixed in the slots by a spring that surrounds the conductor bars and has a wave-like cross section.
DE 18 16 283 discloses a device for fixing winding bars or coils in the slots of the iron body of an electric machine. The slot is closed off by at least one closure piece extending over at least a portion of the iron length. The space of the slot between the slot closure piece and the slot base that is not filled by the winding is filled by a tubular hollow body that consists of an elastic and magnetic material and in whose interior a specific controllable pressure is generated continuously by a pressure-generating system connected to one of its ends so that a specific radial pressure is exerted continuously on the bars or coil of the winding.
DE 32 41 410 A1 discloses a device for fixing the windings of electric machines. The windings consist of individual coils and are inserted into stator slots. In each case a slot closure is formed from a slot closure wedge, from a spring element and from a spring support.
EP 0 489 882 B1 discloses a method for producing the electrical insulation of the winding of an electric machine that has winding sections inserted with play into slots of the rotor or stator. A laminate that expands under heat and that contains an elastically compressible mass of highly elastic fibers is introduced between the slot surface and the winding sections.
DE 10 2015 216 840 A1 discloses a stator for an electric machine. The stator has a lamination stack with slots that extend in an axial direction of the stator. Electrically conductive bars constitute electrical windings of the stator and are arranged respectively in the slots. Each bar is insulated electrically with respect to the lamination stack by a respective electrical insulation element. The electrical insulation element is a hose formed from a thermoplastic and surrounds the bar.
It is an object of the invention to improve a stator with regard to the service life thereof and/or to the producibility thereof.
A stator of an electric machine has a stator lamination stack that comprises stator laminations and at least one stator winding that comprises conductor bars arranged in slots of the stator lamination stack and fixed in the slots of the stator lamination stack with the aid of a fixing device. At least one clamping stator lamination has a clamping geometry and serves as the fixing device. This provides inter alia the advantage that no additional components are required for realizing the fixing device. In this way, the service life of the preferably directly cooled stator can be increased significantly. Furthermore, impregnation or casting with a resin can be dispensed with. In this way, an otherwise necessary manufacturing step is omitted.
The clamping geometry may have at least one clamping projection, such as a clamping lug formed directly on the clamping stator lamination.
The clamping geometry may comprise at least two clamping projections that face one another in a slot. In this way, the fixing of the conductor bars in the slot is considerably simplified.
The clamping geometry may have at least one clamping projection arranged in a slot base. The slot, on the side facing away from the slot base, may be closed off by a closure piece. The clamping projection in the slot base allows a sufficient clamping force to be realized between the slot base and the closure piece in a simple manner.
A protective layer may be formed at least partially between the clamping projection and the conductor bars of the stator winding. The protective layer may be formed by encapsulating the conductor bars with a plastic. The protective layer protects a primary insulation on the conductor bars from damage.
Direct winding cooling may be achieved by having a flow cross section for the cooling medium to remain free in the slot. The claimed clamping geometry prevents undesired relative movements of the conductor bars in relation to one another and/or movement of the conductor bars in the slot.
The stator lamination stack may comprise at least two clamping stator laminations and no clamping projection between the stator laminations. Thus, a sufficient clamping action can be achieved simply with just two clamping stator laminations. Depending on the design and size of the stator lamination stack, it is also possible for more than two, for example three or four, clamping stator laminations to be combined with a desired number of stator laminations without a clamping projection.
The clamping projection may be manufactured in the clamping stator lamination in a separation process, such as punching, as is also used for the production of conventional stator laminations. In this way, the outlay for production can be kept low.
The clamping projection on the clamping stator lamination may be deformed in the stator lamination stack such that the deformed clamping projection makes it possible for the conductor bars of the stator winding to be clamped resiliently. The deformation may be realized, for example, using a suitable deforming tool that is introduced into the packed stator lamination stack.
The invention also relates to a clamping stator lamination for a previously described stator. The clamping stator lamination is able to be handled separately.
Further advantages, features and details of the invention will emerge from the description below in which various exemplary embodiments are described in detail with reference to the drawing.
Intermediate spaces 48 remain free between the conductor bars 41 to 44 and the clamping stator lamination 8 and accommodate passage of a cooling medium (not illustrated in
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2019 113 785.3 | May 2019 | DE | national |
