Rotor comprising interpolar regions with cooling channels

Abstract

The invention relates to a rotor for a rotary electric machine, extending along a longitudinal axis and including: an assembly of electrical sheets forming projecting poles, two projecting poles defining an interpolar region therebetween; and at least two internal cooling channels formed in the assembly of electrical sheets in at least one interpolar region.

Claims

1. A rotor for an electrical rotating machine, extending along a longitudinal axis, comprising: an assembly of magnetic sheets forming salient poles, two salient poles defining between them an interpolar region, and at least two internal cooling channels formed in the assembly of magnetic sheets and integrally formed therewith in at least one interpolar region, a cooling fluid flowing along said internal cooling channels, the assembly of magnetic sheets comprising a stacking of identical magnetic sheets one in contact with the other.

2. The rotor as claimed in claim 1, the magnetic sheets being identical and in one piece.

3. The rotor as claimed in claim 1, from 3 to 15 internal cooling channels being formed in each interpolar region.

4. The rotor as claimed in claim 1, the cooling channels being separated within each interpolar region by fins.

5. The rotor as claimed in claim 1, the cooling channels making the whole length of the assembly of magnetic sheets of the rotor.

6. The rotor as claimed in claim 1, the cooling channels being placed continuously along the longitudinal axis of the rotor.

7. The rotor as claimed in claim 1, the interpolar regions each having a dentate shape defining teeth.

8. The rotor as claimed in claim 1, each interpolar region having a cut-out section representing more than 25% of its total section.

9. An electrical rotating machine comprising a rotor as claimed in claim 1.

10. An electrical rotating machine comprising a fan, and a rotor extending along a longitudinal axis and comprising: an assembly of magnetic sheets forming salient poles, two salient poles defining between them an interpolar region, and at least two internal cooling channels formed in the assembly of magnetic sheets and integrally formed therewith in at least one interpolar region, the air aspirated by the fan passing through said internal cooling channels, the assembly of magnetic sheets comprising a stacking of identical magnetic sheets one in contact with the other.

Description

BRIEF DESCRIPTION DRAWINGS

(1) FIG. 1 is a schematic and partial perspective of an example of a pack of magnetic sheets of a rotor according to the invention,

(2) FIG. 2 is a front view along II of FIG. 1,

(3) FIG. 3 is a view similar to FIG. 1 of another example of a pack of magnetic sheets of a rotor according to the invention, and

(4) FIG. 4 represents in isolation and partially a salient pole and an interpolar region according to an exemplary embodiment of the invention.

DETAILED DESCRIPTION OF INVENTION

(5) FIG. 1 shows a first example of magnetic mass of a rotor 1 which extends along a longitudinal axis X and comprises an assembly of magnetic sheets 2, forming salient poles 3, being four in number in the example illustrated, the invention not however being limited to a particular polarity.

(6) As can be seen in FIG. 1, each pole 3 comprises a pole body 3b, which extends along a center line Y, and two pole shoes 3a which protrude in the circumferential direction.

(7) Two adjacent poles 3 define between them an interpolar region E.

(8) Electrical conductors are wound around each pole 3 and define windings not shown.

(9) Each metal sheet is preferably in one piece being cut out from one and same magnetic band.

(10) The rotor 1 may comprise tie-rods not shown for retaining the assembly of magnetic sheets 2 passing through the rotor mass by virtue of openings 11 situated on the poles 3.

(11) A central housing 8, furnished with an anti-rotation means 9, is arranged in the pack in order to receive a shaft not shown.

(12) The magnetic mass of the rotor 1 may also comprise, as illustrated, housings 10 for receiving dampers not shown.

(13) According to the invention, at least two internal cooling channels 5 run axially through each interpolar region E, for example seven channels, as illustrated in FIGS. 1 and 2.

(14) Fins 4 placed in the interpolar regions E separate the various cooling channels 5.

(15) The cooling channels 5 are for example made in an extension 18 in the form of a right angle, with sides parallel to the faces 19 opposite the pole shoes 3a.

(16) In the example of FIGS. 1 and 2 the cooling channels 5 run through the whole length L of the rotor 1 continuously without interruption.

(17) The magnetic mass may be formed by the stacking of identical magnetic sheets, an additional cooling channel 7 being able to be formed by cutting out the metal sheet within the pole shoes 3a. Several additional channels 7 may be arranged within the pole shoes 3a.

(18) In the variant illustrated in FIG. 3, the interpolar regions E each have a dentate shape defining teeth 6, being five in number per interpolar region E in the example described, the invention however not being limited to a particular number of teeth.

(19) The cooling channels 5 are arranged in the teeth 6, and the gap 20 between the teeth 6 defines a passageway of widened section for the cooling fluid.

(20) The axial dimension L.sub.a along the axis X of a tooth 6 is for example equal to the dimension L.sub.e of the gap 20 between two teeth 6.

(21) Advantageously, the interpolar regions E advantageously have no teeth at one of their axial ends, for example the end 15, as shown in FIG. 3.

(22) Each interpolar region E has a total section s.sub.t, shown with hatched lines in FIG. 4, and a cut-out section s.sub.a defined by the cooling channels 5 running through the interpolar region E. The cut-out section s.sub.a, preferably represents more than 25% of the total section s.sub.t of the interpolar region E.

(23) The channels 5 may have different sections within one and the same interpolar region E.

(24) In order to obtain the configuration illustrated in FIG. 3, where the interpolar channels are discontinuous, it is possible to use identical magnetic sheets which are assembled in packs with a thickness L.sub.a and placed in a staggered manner with, in the four-pole example illustrated, a reversal of the packs in order to make the regions with channels and those without channels alternate.

(25) The rotor 1 is for example incorporated into an electrical rotating machine, not shown, comprising a centrifugal fan. As a variant, the fan is a multi-channel fan. In yet another variant, the fan is made by placing in series a centrifugal fan and an axial fan.

(26) The air aspirated by the fan passes through the cooling channels 5 that are present in the interpolar regions E situated between two adjacent salient poles 3. Moreover, the air can circulate in the air gap and through the channels 7 arranged in the pole shoes 3a of the salient poles 3.

(27) The invention is not limited to the examples that have just been described.

(28) It is possible for example to combine the features described with reference to various embodiments within variants that are not illustrated.

(29) The fins 4 may be of any shape.

(30) The invention may be applied to rotors with fitted pole shoes. The invention is not limited to particular salient poles.

(31) The expression comprising one must be understood to be synonymous with comprising at least one, unless the contrary is specified.