Synchronous electrical machine, and associated propulsion oriented drive device, boat, and method for cooling such a machine
Provided is a synchronous electrical machine that includes a machine housing having a stator and a rotor lodged in the stator, the rotor being separated from the stator by an airgap, and the machine housing dissipating thermal losses generated by the stator. The stator having stacks of laminations and at least one channel extending along a longitudinal direction of the stator and formed in the laminations, two adjacent stacks of laminations being separated by pins or spacers to form an extraction duct connected to the channel, the machine housing further having an extraction opening so that a fluid injected in the air gap at the ends of the stator flows in the extraction duct and in the channel, and is extracted from the machine through the opening to cool the stator and the rotor.
1 . A synchronous electrical machine comprising:
a machine housing including:
a stator and a rotor lodged in the stator, the rotor (i) being separated from the stator by an airgap and (ii) made of individual poles obtained with either magnet blocks or wounded coils, the stator comprising stacks of laminations and at least one channel extending along a longitudinal direction of the stator and formed in the laminations, two adjacent stacks of laminations being separated by pins or specific spacers to form an extraction duct connected to the channel; and
an extraction opening so that a fluid being (i) cooled and delivered via a cooling fluid unit and (ii) injected in the air gap at the ends of the stator flows in the extraction duct and in the channel, and is extracted from the machine through the extraction opening to cool the stator and the rotor; and
wherein an entire circumference of the stator is in direct contact with the machine housing, the machine housing surrounding the stator in such a manner that there is no air layer between the stator and the machine housing, thereby allowing an efficient thermal exchange by conduction with a liquid surrounding the housing without compromising the air circulation inside the machine.
2 . The synchronous electrical machine according to claim 1 , wherein the stator comprises a plurality of tie rods passing through the stacks of laminations and evenly distributed along a diameter of the stator to maintain the stacks of lamination compacted, the channel being disposed on the said diameter.
3 . The synchronous electrical machine according to claim 2 , wherein the stator comprises a plurality of channels evenly distributed along the said diameter, at least one channel being interposed between two tie rods.
4 . The synchronous electrical machine according to claim 2 , wherein the tie rods are made of non-magnetic material.
5 . The synchronous electrical machine according to claim 1 , wherein the rotor comprises permanent magnets.
6 . The synchronous electrical machine according to claim 4 , wherein the rotor comprises permanent magnets.
7 . The synchronous electrical machine according to claim 6 , wherein the permanent magnets are arranged in U or V shapes.
8 . The synchronous electrical machine according to claim 1 , wherein the rotor comprises a plurality of magnetic rotor pole cores evenly distributed around the rotor and rotor coils, each rotor coil being wounded around a different magnetic rotor pole core, the said machine comprising supply means to fed the rotor coils.