Closed rotating electrical machine comprising an internal air cooling system of the magnets in the rotor

Patent metadata

Field	Value
Publication number	US-11005331-B2
Application number	US-201816479503-A
Country	US
Kind code	B2
Filing date	Jan 17, 2018
Priority date	Jan 25, 2017
Publication date	May 11, 2021
Grant date	May 11, 2021

Abstract

The invention relates to an enclosed rotary electrical machine including a cooling system comprising two internal fans ( 181, 182 ) fixedly mounted on shaft ( 160 ) at both ends of rotor ( 150 ). The rotor and stator ( 190 ) are contained in an enclosure sealed by two flanges. The fans allow dual air circulation in flux barriers surrounding the rotor magnets and formed by axial recesses running throughout the rotor, and also air circulation in the space created between the internal fans and the inner faces of the flanges comprising fins ( 113, 123 ) which orient the air flows created by the fans to capture the heat thereof. External cooling allows the enclosure and the flanges to be cooled, by air or liquid cooling.

First claim

The invention claimed is:

1. A rotary electrical machine with an enclosure comprising:
a stator disposed in the enclosure and comprising windings;
a rotor comprising a body fastened to a shaft which rotates about a central axis, the rotor being mounted to rotate in the stator and comprising first recesses housing magnetic flux generators and second recesses providing magnetic flux barriers, the first and second recesses being elongated and running along the central axis;
bearings which each support one end of the rotating shaft;
a front flange and a rear flange respectively disposed at two opposite front and rear ends of the enclosure, the front and rear flanges each including a seal for sealing the enclosure, an inner face, an outer face and a central housing receiving one of the bearings, the inner face of the flanges comprising fins disposed on a peripheral part of the central housing; and
a cooling system comprising internal fans, each internal fan being fixedly mounted on the rotating shaft between the body of the rotor and one of the bearings to provide, upon rotation of the shaft, a first air flow in the second recesses of the rotor and a second air flow between each internal fan and the inner face of the front flange or the rear flange, and wherein
each internal fan comprises an inner face, an outer face, a central opening for passage of the rotating shaft and an alternation of open radial sectors and closed radial sectors which divide a surface of the internal fan and are separated by radial walls which are orthogonal to the central axis which provide protruding blades on an outer face of the internal fan.

2. An electrical machine as claimed in claim 1 , wherein the internal fans are circular in shape with an inner face thereof comprising a plane part resting on the body of rotor and which is orthogonal to the central axis, the plane part extending in an inclined plane part at each closed radial sector and through opening at each open radial sector.

3. An electrical machine as claimed in claim 2 , wherein:
the rotor comprises n of magnetic poles created by the flux generators and the flux barriers;
each magnetic pole being covered by closed and open radial sectors adjacent to an internal fan; and
the internal fans are mounted with an offset on shaft to match an open radial sector of one internal fan to a closed radial sector of another internal fan along a single axis parallel to the central axis.

4. An electrical machine as claimed in claim 3 , wherein:
a total number of open and closed radial sectors of an internal fan is 2n, and the two internal fans are mounted with an angular offset on the shaft by an angle β which is equal to 360/(2n); and

n is an even integer ranging between 2 and 12.

5. An electrical machine as claimed in claim 4 , wherein the machine is a variable synchronous reluctance machine.

6. An electrical machine as claimed in claim 2 , wherein the machine is a variable synchronous reluctance machine.

7. An electrical machine as claimed in claim 1 , wherein:
the rotor comprises n of magnetic poles created by the flux generators and the flux barriers;
each magnetic pole being covered by closed and open radial sectors adjacent to an internal fan; and
the internal fans are mounted with an offset on the shaft to match an open radial sector of one internal fan to a closed radial sector of another internal fan along a single axis parallel to the central axis.

8. An electrical machine as claimed in claim 7 , wherein:
a total number of open and closed radial sectors of an internal fan is 2n, and the two internal fans are mounted with an angular offset on shaft by an angle which is equal to 360/(2n); and

n is an even integer ranging between 2 and 12.

9. An electrical machine as claimed in claim 8 , wherein the machine is a variable synchronous reluctance machine.

10. An electrical machine as claimed in claim 7 , wherein the machine is a variable synchronous reluctance machine.

11. An electrical machine as claimed in claim 1 , wherein the internal fans and fins on an inner face of the flanges direct air in radially towards winding heads of the stator, then return air flow from the winding heads to the center of the flanges, first along a direction parallel to the central axis at the winding heads, then radially towards the shaft, to form the second air flow created between each internal fan and the inner face of the front or the rear flange.

12. An electrical machine as claimed in claim 1 , wherein the fins of the inner face of the flanges are plane and have a trapezoidal shape comprising bases which are orthogonal to the central axis and a side opposite to the housing is concave.

13. An electrical machine as claimed in claim 1 , comprising external cooling for cooling the enclosure and the front flange and the rear flange.

14. An electrical machine as claimed in claim 13 , wherein the external cooling comprises an external fan disposed opposite the outer face of the rear flange which is mounted on the rotating shaft to direct outside air along the enclosure in a direction toward the front flange.

15. An electrical machine as claimed in claim 14 , wherein the
the enclosure includes an outer surface comprising elongated cooling fins extending along an axis parallel to the central axis of rotating shaft; and
the rear flange comprises a central part formed as a crown which is connected to a cylindrical peripheral part and at least one opening is provided between the central part and the peripheral part of the rear flange for directing the outside air which is directed by external fan into passages formed by the cooling fins of the outer surface of the enclosure.

16. An electrical machine as claimed in claim 15 , wherein the external fan comprises a wheel for directing outside air which is fastened to the shaft and a protective plate comprising orifices allowing the directed outside air to enter the plate which is attached to a peripheral part of the rear flange.

17. An electrical machine as claimed in claim 13 , wherein the external cooling comprises a coolant circuit including a coolant inlet, a coolant outlet and coolant lines in contact with the enclosure, wherein the coolant circulates to cool the enclosure and the front and the rear flanges, and wherein the lines are integrated in the enclosure.

18. An electrical machine as claimed in claim 1 , wherein the coolant comprises water.

Assignees

• Ifp Energies Now
• Mavel Srl

Inventors

• Dib Wissam
• Favre Luca
• Bettoni Davide

Classifications

• H02K9/06

  with fans or impellers driven by the machine shaft · CPC title

• H02K5/203

  specially adapted for liquids, e.g. cooling jackets · CPC title

• H02K7/083

  radially supporting the rotary shaft at both ends of the rotor (H02K7/086, H02K7/09 take precedence) · CPC title

• H02K1/32

  with channels or ducts for flow of cooling medium · CPC title

• H02K5/18 Primary

  with ribs or fins for improving heat transfer · CPC title