Cooling ring for a rotating electric machine stator

Abstract

One aspect of the invention relates to a cooling ring 1 for a rotating electrical machine stator, said ring 1 comprising: A first ring portion 2 arranged to, A at a first end 3, be in axial contact with a first end face of a stator; A at a second end 4, be in radial contact with an internal circumferential surface of a housing surrounding the stator, said first ring portion having orifices 5 for conveying coolant; A second ring portion 6 disposed in the axial extension of the first ring portion 1, said second ring portion 6 being arranged to deform axially and ensure contact of the first end 3 with the first end face of the stator. Figure 1

Description

Title of the invention: Cooling ring for a rotating electrical machine stator. Technical field of the invention.

[0001] The present invention relates to a cooling ring for a rotating electrical machine stator. The invention thus relates to the technical field of cooling rotating electrical machine stators. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0002] Rotating electrical machines are known, having a stator with first and second end faces and a winding running longitudinally through the stator and forming a bundle of electrically conductive wires at each end face of the stator. This type of rotating electrical machine is usually equipped with a housing surrounding the stator and a cover located at one end of the housing.

[0003] During operation, the temperature of the rotating electrical machine increases. When the temperature increase is not controlled, the performance of the rotating electrical machine may be degraded and the magnets may become demagnetized.

[0004] In order to contain the temperature of the rotating electrical machine, it is known from document CN-A-118040938 to equip it with two cooling rings assembled one inside the other, these two rings participating together in the cooling of the stator of the rotating electrical machine.

[0005] This ring surrounds one of the wire bundles and extends between the cover and the end face of the stator located opposite the cover. A sealed chamber is thus formed between the outer circumferential surface of the ring and the inner circumferential surface of the housing.

[0006] This ring is provided with a plurality of orifices allowing cooling oil to be distributed from the sealed chamber onto the bundle of electrically conductive wires surrounded by said ring. The oil thus contributes to the cooling of the bundle of electrically conductive wires and, more generally, of the stator.

[0007] It should be noted, however, that a significant variation of + / - 1.5 mm in the stator length is frequently present in stator production batches. This variation is likely to generate a sealing defect between the ring, the cover, and the stator end face, reducing the stator's cooling performance.

[0008] Furthermore, during operation, the stator temperature changes and is likely to alter the stator's dimensions. These changes are also a source of sealing defects. Summary of the invention

[0009] The invention offers a solution to the problems mentioned above, by proposing a cooling ring for a rotating electrical machine stator which makes it possible to ensure, in an inexpensive manner, the sealing of a cooling oil chamber of said stator.

[0010] In this context, the invention thus relates, in its broadest sense, to a cooling ring for a stator of a rotating electrical machine, said ring comprising a longitudinal axis X and • A first ring section constructed and arranged to: • At one end, be in axial contact with an end face of a stator; • At a second end, be in radial contact with an internal circumferential surface of a rotating electrical machine casing surrounding said stator, the first ring part having coolant delivery ports, said ports passing through the thickness of said first ring part; • A second ring part arranged in the axial extension of said first ring part, the second ring part being constructed and arranged to deform axially and ensure contact of the first end of the first ring part with the end face of the stator.

[0011] Thanks to the invention, the second part of the ring can deform axially in order to compensate for any manufacturing defects of the stator and / or assembly of the rotating electrical machine.

[0012] By deforming axially, this second part of the ring can also compensate for changes in the lengths of the stator in operation which would be due to changes in its temperature.

[0013] Axial deformation is understood to mean a deformation whose direction is along the longitudinal axis X.

[0014] Axial contact is understood to mean a contact whose direction is along the longitudinal axis X.

[0015] Radial contact is understood to mean a contact whose direction is perpendicular to the longitudinal axis X.

[0016] In addition to the characteristics just mentioned in the preceding paragraph, the ring according to this aspect of the invention may have one or more complementary characteristics from among the following, considered individually or according to all technically possible combinations.

[0017] According to a non-limiting aspect of the invention, a first annular groove for receiving a first seal is provided axially in the first end of the first part of the ring.

[0018] According to a non-limiting aspect of the invention, the ring comprises a first seal with a rectangular cross-section, said first seal being disposed in the first annular groove

[0019] According to a non-limiting aspect of the invention, at the second end of the first ring part a second annular groove for receiving a second seal is formed radially in an external circumferential surface of the first ring part.

[0020] According to a non-limiting aspect of the invention, the ring comprises a second seal of circular section, the second seal being disposed in the second annular groove.

[0021] According to a non-limiting aspect of the invention, the second ring part comprises at least one opening, said at least one opening passing through the thickness of said second ring part.

[0022] According to a non-limiting aspect of the invention, at least one opening is oblong in shape.

[0023] According to a non-limiting aspect of the invention, at least one opening extends longitudinally between a first end and a second end of the second ring part.

[0024] According to a non-limiting aspect of the invention, at least one opening has a longitudinal axis forming, with an end face of the second part of the ring, an angle between 10° and 80°.

[0025] Another aspect of the invention relates to a rotating electrical machine comprising: • A stator comprising first and second end faces; • A winding running longitudinally through the stator and forming at each of the first and second end faces of the stator respectively first and second bundles of electrically conductive wires; • A casing surrounding the stator; • A cover positioned at one end of the housing, the cover being opposite the first end face of the stator; • A ring according to any one of the aforementioned aspects of the invention, said ring surrounding the first bun; • The first part of the ring being • At its first end, in axial contact with the first end face of the stator; • At its second end, in radial contact with an internal circumferential surface of the housing; • the end face of the second ring part being in contact with the lid.

[0026] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0027] [Fig.1] illustrates a three-dimensional view of a cooling ring for a rotating electrical machine stator according to a non-limiting aspect of the invention.

[0028] [Fig.2] illustrates a two-dimensional view of the cooling ring for a stator of rotating electrical machine illustrated in [Fig.1].

[0029] [Fig.3] presents a schematic cross-sectional view of an example of a non- limiting of a rotating electrical machine according to the invention equipped with a cooling ring as illustrated in figures 1 and 2. DETAILED DESCRIPTION

[0030] The figures are presented for illustrative purposes only and are in no way limiting of the invention.

[0031] Unless otherwise specified, the same element appearing on different figures has a unique reference.

[0032] Figures 1 and 2 schematically illustrate a cooling ring 1 for a rotating electrical machine stator. The cooling ring 1 has a longitudinal axis X.

[0033] The cooling ring 1 comprises a first part of a ring 2 having a first end 3 constructed and arranged to be in axial contact with a first end face of a stator.

[0034] The first ring part 2 also includes a second end 4 arranged to be in radial contact with an internal circumferential surface of a rotating electrical machine housing surrounding the stator.

[0035] The first ring portion 2 also includes coolant delivery ports 5. The coolant delivery ports 5 pass through the thickness of the first ring portion 2.

[0036] The cooling ring 1 further advantageously comprises a second ring part 6.

[0037] The second ring portion 6 is arranged in the axial extension of the first ring portion 2. The second ring portion 6 is constructed and arranged to deform axially, in other words along a longitudinal axis direction X, and ensure the contact of the first end 3 of the first part of ring 2 with the first end face of the stator.

[0038] The cooling ring 1 has a first annular groove 7 for receiving a first seal 8. The first annular groove 7 is formed axially in the first end 3 of the first part of the ring 2. In other words, the first annular groove 7 is cut along the longitudinal axis X in the end face located at the first end 3 of the first part of the ring 2.

[0039] According to a non-limiting example of embodiment, the first seal 8 disposed in the first annular groove 7 of the first ring part 2 has a rectangular section.

[0040] The second end 4 of the first ring part 2 has a second annular groove 9 for receiving a second seal 10. This second groove 9 is formed radially in an external circumferential surface 11 of the first ring part 2. In other words, the second annular groove 9 is cut in a radial direction perpendicular to the longitudinal axis X in the external circumferential surface 11 of the first ring part 2.

[0041] According to a non-limiting embodiment, the second seal 10 arranged in the second groove 9 has a circular section.

[0042] According to a non-limiting embodiment, the second part of the ring 6 has a plurality of openings 12 through its thickness. Each of these openings 12 has an oblong shape.

[0043] According to this non-limiting embodiment, each of these oblong-shaped openings 12 extends longitudinally between a first end 13 and a second end 14 of the second part of the ring 6.

[0044] According to this non-limiting embodiment example, each opening 12 has a longitudinal axis 15 forming with an end face 16 of the first end 13 of the second part of ring 6, an angle a between 10° and 80°.

[0045] These openings 12 facilitate axial deformation along the longitudinal axis X of the second part of ring 6 and allow contact of the first end 3 of the first part of ring 2 with the first end face of the stator.

[0046] It is understood that a person skilled in the art may consider other forms of opening. Furthermore, these openings may be replaced by other technical solutions allowing axial deformation of the second ring part, for example the use of a particular elastic material.

[0047] Fig. 3 schematically illustrates a rotating electrical machine 17 equipped with a cooling ring 1 as illustrated in Figures 1 and 2.

[0048] The rotating electrical machine 17 comprises a stator 18 having a first end face 19 and a second end face 20.

[0049] A winding passes longitudinally through the stator 18 and forms at each of its first and second end faces 19, 20, respectively first and second buns 21, 22 of electrically conductive wires.

[0050] The rotating electric machine 17 further comprises a housing 23 surrounding the stator 18. A cover 24 is disposed at one end of the housing 23 and is opposite the first end face 19 of the stator 18. The ring 1 surrounds the first coil 21 of electrically conductive wires.

[0051] The first end 3 of the first ring part 2 is in axial contact with the first end face 19 of the stator 18. In addition, the second end 4 of the first ring part 2 is in radial contact with an internal circumferential surface 25 of the housing 23. A sealed chamber 26 is thus formed between the external circumferential surface of the ring 1 and the internal circumferential surface 25 of the housing 23.

[0052] The orifices 5 in the first part of ring 2 allow cooling oil to be distributed from the sealed chamber 26 onto the first bundle 21 of electrically conductive wires surrounded by ring 1. The oil thus contributes to the cooling of the first bundle 21 and more generally of the stator 18.

[0053] The second part of the ring 6 has, for its part, an end face 16 in contact with the cover 24.

[0054] Thus, thanks to the axial deformation capacity of the second part of ring 6, it is possible to compensate for a possible axial dispersion of + / - 1.5 mm between different stators and also to compensate for changes in stator length during operation.

Claims

Demands

1. Cooling ring (1) for a stator (18) of a rotating electrical machine (17), said ring (1) having a longitudinal axis (X) and: - A first ring portion (2) arranged to • At a first end (3), be in axial contact with a first end face (19) of a stator (18); • At a second end (4), be in radial contact with an internal circumferential surface (25) of a housing (23) surrounding said stator (18), said first ring portion (2) having orifices (5) for conveying coolant through its thickness;- Said cooling ring (1) being characterized in that it comprises a second ring part (6) arranged in the axial extension of said first ring part (1), said second ring part (6) being arranged to deform axially and ensure the contact of said first end (3) with said first end face (19) of the stator (18).;

2. Ring (1) according to the preceding claim, characterized in that a first annular groove (7) for receiving a first seal (8) is provided axially in the first end (3) of the first part of the ring (2).

3. Ring (1) according to the preceding claim, characterized in that it comprises a first seal (8) having a rectangular section, said first seal (8) being disposed in the first annular groove (7).

4. Ring (1) according to any one of the preceding claims, characterized in that at the second end (4) of the first ring part (2), a second annular groove (9) for receiving a second seal (10) is formed radially in an external circumferential surface (11) of said first ring part (2).

5. Ring (1) according to the preceding claim, characterized in that it comprises a second seal (10) of circular section, said second seal (10) being disposed in the second annular groove (9).

6. Ring (1) according to any one of the preceding claims, characterized in that the second ring part (6) has at least one opening (12), said at least one opening (12) passing through the thickness of said second ring part (6).

7. Ring (1) according to the preceding claim, characterized in that at least one opening (12) is oblong in shape.

8. Ring (1) according to the preceding claim, characterized in that at least one opening (12) extends longitudinally between a first end (13) and a second end (14) of the second part of the ring (2).

9. Ring (1) according to the preceding claim, characterized in that at least one opening (12) has a longitudinal axis (15) forming, with an end face (16) of the second part of the ring (6), an angle (a) between 10° and 80°.

10. Rotating electrical machine (17) comprising: - A stator (18) having first and second end faces (19, 20); - A winding running longitudinally through said stator (18) and forming at each of said first and second end faces (19, 20) of said stator (18), respectively, first and second coils (21, 22) of electrically conductive wires; - A housing (23) surrounding said stator (18); - A cover (24) disposed at one end of said housing (23), said cover (24) being opposite said first end face (19) of said stator (18); - Said rotating electrical machine (17) being characterized in that it comprises a ring (1) according to any one of the preceding claims, said ring (1) surrounding said first coil (21);- The first part of the ring (2) being • At its first end (3), in axial contact with said first end face (19) of said stator (18); • At its second end (4), in radial contact with an internal circumferential surface (25) of said stator (18); the end face (16) of the second part of the ring (2) being in contact with said cover (24).

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