Patent ID: 12206318

Additional features, aspects and advantages of the invention or its exemplary embodiments will become apparent from the detailed description in conjunction with the claims.

DETAILED DESCRIPTION

FIG.1is a schematic illustration of a first embodiment of a stator component100for a stator of an electric machine, in particular of an electric motor. The stator component100is composed of a plastics workpiece10and a stator laminated core15. The plastics workpiece10comprises a can20, insulating sleeves30and an upper end disk40and/or a lower end disk42. The stator component100is a component of a stator of an electric machine (not illustrated in any more detail here). The electric machine comprises the stator and a rotor. The rotor is arranged in a receiving space formed by the stator. The electric machine may be used as a traction electric motor in an electric vehicle.

The stator laminated core15is placed into a tool and is then overmolded with plastic by way of an injection molding process or a transfer molding process to from the plastics workpiece10. The stator component10is thus a composite part composed of the stator laminated core15and the plastics workpiece10fixedly connected thereto by overmolding. The plastics workpiece10is composed of a magnetically neutral and electrically insulating plastic, for example PA (polyamide), PP (polypropylene) and/or PS (polystyrene).

As illustrated inFIG.2, the plastics workpiece10has a hollow cylindrical can20which, in the assembled state of the electric machine, is arranged in an air gap between the rotor and the stator and separates the stator from the rotor. This is necessary if the stator is cooled using a liquid coolant. Insulating sleeves30are formed on an outer surface22of the can20and can receive conductor bars (hairpins), which in some embodiments are composed of copper. The insulating sleeves of the illustrated embodiment surround the outer surface22of the can20in ring-shaped fashion and are directed radially outward.

As illustrated inFIG.3, an insulating sleeve30encloses a groove32with a rectangular cross section for receiving a conductor bar or track39that also is of rectangular cross section, and extends parallel to the longitudinal axis of the can20. Each insulating sleeve30has two side walls34that are connected at their inner end edges to the outer surface22of the can20. One outer wall36is connected to the outer end edges of the side walls34so that the side walls34and the outer wall36collectively form the groove32for the insertion of a conductor bar or track39. Formations for the throughflow of a coolant may also be provided in the grooves32. It is however also possible for the conductor bars39to be provided with formations for a coolant. The segments of the stator laminated core15(not illustrated in any more detail here) are arranged in the intermediate spaces38between the insulating sleeves30.

FIG.4illustrates the plastics workpiece10with the upper end disk40and the lower end disk42. The upper end disk40is arranged in the upper end region of the can20, and the lower end disk42is arranged in the lower end region of the can20. In particular, the upper end disk40and the lower end disk42are identical so that the stator component100is of symmetrical construction. It is however conceivable for the upper end disk40and the lower end disk42to be designed differently from one another. The plastics workpiece10of some embodiments may have only one end disk40.

The end disks40,42are annular and are formed on the outer surface22of the can20and/or the outer surfaces of the insulating sleeves30. In particular, the end disks40,42have recesses44and/or openings for the installation and fixing of the conductor tracks. In this way, the deformation and welding of the conductor tracks to form a winding head during the assembly of the electric machine can be simplified, because the end disks40,42are used for fixing the conductor tracks. This method step can be performed in automated fashion with the aid of robots.

The stator component100is formed as a single piece and is composed of the stator laminated core15and the plastics workpiece10molded thereon. The stator component100forms a composite part that is distinguished by a major reduction of the components required. By virtue of the stator laminated core15being overmolded with plastic, the use of a large number of materials can be dispensed with, for example because there is no need for insulating paper strips for the grooves32. The insulator sleeves30amply isolate the conductor tracks electrically from the stator laminated core15, such that no further materials are necessary. In this way, the production process of the stator is simplified, because fewer components have to be assembled. Furthermore, recyclability is increased as a result.

A low weight is made possible due to the smaller number of components, and less expensive base materials. The firm connection of the stator laminated core15to the plastics workpiece10furthermore results in greater strength of the stator component100. In this way, the wall thickness of the can20can be reduced, and this in turn leads to a reduction of the air gap between the stator and the rotor. A small air gap however increases the efficiency of the electric machine.

Manufacturing tolerances of the segments of the stator laminated core15can be compensated by virtue of cavities being filled with the plastics overmolding, such that the produced stator components100are distinguished by a high level of standardization and high surface quality. The stator component100can be equipped with two end disks40,42arranged respectively at the upper and lower end regions of the can20. Thus, the installation of the conductor tracks can be simplified. Altogether, the number of method steps can thus be reduced so that a more efficient production and a cost saving can be achieved. This leads overall to less expensive and more environmentally friendly production of an electric motor.