Electrical machine
An electrical machine, in particular an electric motor of a motor vehicle, having a stator and having a rotor which has a rotation axis. An electrical machine can be a brushless electric motor (DC motor) or a synchronous machine, but also a generator. The stator or the rotor has an electromagnet structure, and the other has a permanent-magnet structure which comprises a first quantity of permanent magnets and a second quantity of permanent magnets. At at least the operating temperature (T), the magnetic coercive field strength (Hcji) of the first quantity is greater than the magnetic coercive field strength (Hcj2) of the second quantity. Further, two methods for producing hybrid magnets are provided.
1. A method for producing a hybrid magnet of an electrical machine, the method comprising:
forming a core from a second set;
placing the core in a press mold; and
filling the press mold with a first set, whose magnetic coercive field strength at, at least, the operating temperature of the electrical machine is greater than a magnetic coercive field strength of the second set,
wherein the first set is sintered in the press mold,
wherein an external magnetic field is applied during the filling or sintering, and
wherein the external magnetic field is oriented parallel to a magnetization direction of the core, such that the hybrid magnet has a linear magnetization in a single direction.
2. The method according to claim 1 , wherein a pocket of a lamination stack of a rotor or stator of the electrical machine is selected as the press mold.
3. The method according to claim 1 , wherein the press mold is filled partially with the first set before placing the core in the press mold.