Rotating electrical machine for vehicles with liquid cooling
An embodiment of a rotating electrical machine has: a shaft rotatably mounted to rotate around a central rotation axis; a rotor carried by the shaft; a stator which supports stator windings and is arranged around the rotor to enclose the rotor therein; a cylindrical casing which encloses the stator therein; and a cooling circuit which is intended for the circulation of a cooling fluid, is obtained at the casing, has a single common inlet opening for the cooling fluid axially arranged in the centre of a lateral wall of the casing, and two helicoidal paths, each of which is a mirror-image twin of the other one, centrally originates from the common inlet opening and extends from the centre of the casing towards a corresponding end of the casing.
1. A rotating electrical machine comprising:
a shaft, which is mounted so as to rotate around a central rotation axis;
a rotor, which is supported by the shaft;
a stator, which supports stator windings provided with heads and is arranged around the rotor so as to surround the rotor;
a cylindrical casing, which contains in its inside the stator;
a cooling circuit, which is intended for the circulation of a cooling fluid and is obtained at the casing, has a single common inlet opening for letting the cooling fluid in, which is axially arranged at the center of a lateral wall of the casing, and has two helicoidal paths, each of which is a mirror-image twin of the other one, centrally originates from the common inlet opening and extends from the center of the casing towards a corresponding end of the casing;
two annular distribution chambers, each of which has a circular shape, is arranged at an end of the casing and forms the end of a corresponding helicoidal path; and
two collecting chambers, in which the heads of the stator windings are arranged:
wherein each annular distribution chamber has a plurality of outlet through holes, which are arranged in a radial fashion, open through an inner wall of the annular distribution chamber in order to lead to the central rotation axis, and establish a communication between each distribution chamber and a corresponding collecting chamber.
2. An electrical machine according to claim 1 , wherein at least part of the outlet through holes are oriented towards the heads of the stator windings.
3. An electrical machine according to claim 1 , wherein part of the outlet through holes are oriented towards ends of the rotor.
4. An electrical machine according to claim 1 , wherein each collecting chamber presents a corresponding outlet opening for letting the cooling fluid out.
5. An electrical machine according to claim 1 , wherein each collecting chamber is radially arranged more on the inside than the corresponding distribution chamber.
6. An electrical machine according to claim 1 , wherein each collecting chamber is axially arranged more on the inside than the corresponding distribution chamber.
7. An electrical machine according to claim 1 , wherein each helicoidal path is internally delimited by an outer surface of the stator and laterally as well as externally delimited by the lateral wall of the casing.
8. An electrical machine according to claim 1 , wherein an inlet duct is provided, which is suited to deliver the cooling fluid, ends in the common inlet opening and is oriented in a tangential fashion with respect to the casing.