Rotor and electric machine equipped with such a rotor

Abstract

Rotor of an electrical machine, in particular an electrical machine of a motor vehicle, said rotor comprising a body (2) electrically connected to a ground and provided with at least one notch (12, 12'), said rotor further comprising at least one winding (16, 16') of an electrical conductor (17, 17') arranged at least partially in said notch (12, 12'), said rotor being configured to electrically insulate said winding (16, 16') from said body (2), said rotor further comprising a wedging member (18), not electrically connected to the ground, and applying the winding (16, 16') in the notch (12, 12'), said winding (16, 16') being in contact with said wedging member (18). Figure for abstract: Figure 1

Description

Title of the invention: Rotor and electric machine equipped with such a rotor

[0001] The invention relates to a rotor and an electrical machine provided with such a rotor. It is intended, in particular, for motor vehicles.

[0002] In this field, electrical machines are known in which a rotor comprises a body electrically connected to a ground. The body is provided with notches for receiving windings of an electrical conductor intended to generate a magnetic flux. The rotor comprises a sheet covering a portion of the windings projecting at an external longitudinal edge of the notches. Said sheet makes it possible to insulate the body and this portion of the windings from each other. In order to ensure that it is held in position, the insulating sheet is sandwiched between the winding and a wedging member.

[0003] The latter is used to apply the windings in the notches in order to limit friction of the turns of the winding against each other as well as friction of the external turns of the windings against the walls of the notches. Such a configuration has the advantage of avoiding a phenomenon of corrosion by fretting of the windings, a phenomenon all the more critical with the high rotation speeds encountered in the electrical machines used to power a motor vehicle and the radial displacement forces which are then applied to the windings.

[0004] In this context, the insulating sheet interposed between the wedging member and the windings generates assembly difficulties which limit the force applied to the windings by the wedging member and, consequently, good retention of the windings in the notches.

[0005] The invention aims to at least partially overcome the above drawbacks and to this end proposes a rotor for an electrical machine, in particular an electrical machine for a motor vehicle, said rotor comprising a body electrically connected to a ground and provided with at least one notch, said rotor further comprising at least one winding of an electrical conductor arranged at least partially in said notch, said rotor being configured to electrically insulate said winding from said body, said rotor further comprising a wedging member, not electrically connected to the ground, and applying the winding in the notch, said winding being in contact with said wedging member

[0006] The contact between the winding and the wedging member allows direct action of one on the other without interposition of the electrical insulation of the state of the art which is useless at this level because the wedging member is not connected to the ground. Maintaining the winding in the notch is thus favored which makes it possible to limit the corrosion by fretting of the winding.

[0007] According to various additional characteristics of the invention, which may be taken together or separately and which form as many embodiments of the invention: - said rotor comprises an insulating groove between said winding and said body, - said insulating groove extends radially outwardly from an external longitudinal edge of said notch, - said isolating groove extends angularly between said body and said wedging member, - said rotor comprises a slot bottom insulator, arranged between walls of the slot and said winding, - said notch bottom insulator comprises a protrusion emerging from said notch and covering the external longitudinal edge of said notch, - said protrusion extends radially in said insulating groove between said body and said wedging member, - said body comprises at least one pole provided with a pole foot and a pole head extending radially outwardly from said pole foot, - said pole head angularly projects beyond said pole foot by a portion, called longitudinal, - said pole heads protrude angularly on either side of their pole base, - said notch is located in the pole foot near said pole head, - said insulating groove is formed in said longitudinal portion of the pole head, - said longitudinal portion has a contact lip with said wedging member, - said contact lip radially closes said isolation groove externally, - said notch has an opening, said winding being flush with said opening and / or projecting from said opening towards said wedging member, - said winding comprises a row, called a support row, formed with said electrical conductor, said support row being in contact with said wedging member, - said support row is located outside said notch, - said wedging member is configured to press uniformly on the winding towards a bottom of said notch, - said wedging member has at least one large face, intended to form a contact zone for said support row, - said winding comprises turns wound in rows following one another radially around the pole and in layers following one another axially along the pole, - said support row is formed from portions of the conductor belonging to an outer row of said winding of turns, - said wedging member is arranged between a first and a second of the windings so as to weave the first winding in a first of said notches and the second winding in a second of said notches, - a first of said large faces is in contact with said first winding and a second of said large faces is in contact with the second winding, - said wedging member exerts a force applying each of the windings in its notch in a support direction, - the support direction of the first winding and the support direction of the second winding form a first angle between them, - said first and second large faces form a second angle between them, - said first and second angles are substantially supplementary, - said notch bottom insulation extends continuously between the first and second notches, - said notch bottom insulator passes opposite a top of said wedging member connecting said first and second large faces, - said rotor comprises a plurality of poles, extending radially, said wedging member extending between two angularly adjacent poles, - said wedging member is configured to be mounted axially in said body.

[0008] The invention also relates to an electrical machine comprising a rotor as described above.

[0009] The invention will be better understood, and other aims, details, characteristics and advantages thereof will appear more clearly during the detailed explanatory description which follows, of at least one embodiment of the invention given by way of purely illustrative and non-limiting example, with reference to the following appended schematic drawing:

[0010] [Fig-1] schematically illustrates in cross-sectional view a portion of a rotor according to the invention.

[0011] It should first be noted that the terms "first", "second", "third", ... are only used to distinguish the components concerned from each other and do not indicate an order or a possible importance of said components.

[0012] As illustrated in the figure, the invention relates to a rotor of an electric machine, in particular an electric machine of a motor vehicle. It is in particular a rotor of an electric machine used for the motorization of said vehicle.

[0013] Said rotor comprises a body 2 electrically connected to a mass. Said body 2 is formed, for example, of plates stacked in a direction parallel to an axis of rotation of the rotor, here perpendicular to the plane of the figure.

[0014] Said body 2 comprises several poles 4 extending radially. Said poles 4 are regularly distributed angularly around the axis of rotation of the rotor. In the figure, only two of said poles are shown, each partially.

[0015] Said poles 4 are provided, for example, with a pole foot 6 and a pole head 8 extending radially outwardly from said pole foot 6. Said pole head 8 projects angularly beyond said pole foot 6 by a portion 10, called longitudinal. Said pole heads 8 here project angularly on either side of their pole foot 6, by such longitudinal portions 10.

[0016] Said body 2 is provided with at least one notch 12, 12'. Said notch(s) 12, 12' are here located in the pole feet 6 close to said pole heads 8. Advantageously, said notch(s) 12, 12' extend longitudinally along the axis of rotation of the rotor. There are two of them per pole here. They open out at two angular faces 14 of said pole feet 6.

[0017] Said rotor 2 further comprises at least one winding 16, 16' of an electrical conductor 17, 17'. Said winding(s) 16, 16' are intended to generate a magnetic flux intended to rotate with the rotor when the electrical machine is operating. Advantageously, one such winding 16, 16' is provided per pole 4.

[0018] Said windings 16, 16' are arranged at least partially in said notches 12. More precisely, here, the same one of said windings 16, 16' passes through the two notches 12, 12' of the same one of said poles 4. In the figure, two different ones of said windings 16, 16' are shown.

[0019] In the illustrated embodiment, said windings 16, 16' comprise turns wound in rows following one another radially around the corresponding pole 4 and in layers following one another axially along said pole 4.

[0020] Said rotor also comprises at least one wedging member 18, not electrically connected to the ground, and applying the winding(s) 16, 16' in their notch 12, 12'.

[0021] According to the illustrated embodiment, each of said wedging members 18 is arranged between a first 16 and a second 16' of the windings so as to weave the first of the windings 16 in a first 12 of said notches and the second of the in bearing 16' in a second 12' of said notches. In other words, each of said wedging members 18 extends between two of said angularly adjacent poles 4. In the figure, only one of said wedging members 18 is visible.

[0022] Said wedging member 18 is configured to press uniformly on the windings 16, '16 towards a bottom of said corresponding notch 12, 12'. Said wedging member 18 has at least one large face, here two large faces 20, 20'. A first 20 of said large faces is in contact with said first winding 16 and a second 20' of said large faces is in contact with the second winding 16'.

[0023] The said wedging member(s) 18 are configured to be mounted axially in the said body, in particular between two angularly successive poles 4. To ensure good retention of the windings 16 in their respective notches 12, the said wedging member(s) 18 are preferably configured to be positioned by sinking radially towards the axis of rotation of the rotor.

[0024] Said wedging member 18 exerts a force applying each of the windings 16, 16' in its notch 12, 12' in a bearing direction, the bearing direction of the first winding 16 and the bearing direction of the second winding 16' forming a first angle between them. Said first and second large faces 20, 20' form a second angle between them. Advantageously, said first and second angles are substantially supplementary. The value of each of these angles depends on the number of poles 4 of the rotor.

[0025] According to the invention, said winding(s) 16, 16' are in contact with the corresponding wedging member 18. The contact between the windings 16, 16' and the wedging member 18 allows direct action of one on the other without interposition of the electrical insulator of the state of the art which is useless at this level because the wedging member is not connected to the ground. In addition, no longer having to ensure good positioning of this electrical insulator using the wedging member 18 makes it possible to better dedicate the location of said wedging member 18 to the windings 16, 16' in the notches 12, 12' and, consequently, to benefit from better maintenance of said windings 16, 16' in said notches 12, 12'.

[0026] Furthermore, said rotor remains configured to electrically insulate said winding(s) 16, 16' from said body 2.

[0027] For this purpose, here, said rotor comprises an insulating groove 22 between said windings 16, 16' and said body 2. Said insulating groove 22 extends radially outwardly from an external longitudinal edge 24 of the corresponding notches 12, 12'. Said insulating groove 22 extends angularly between said body 2 and said wedging member 18 located opposite.

[0028] Advantageously, said rotor further comprises an insulator, called a slot bottom insulator and marked 24, arranged between walls of the notch(s) 12, 12' and the corresponding winding 16, 16'.

[0029] According to the illustrated embodiment, said notch bottom insulator 24 extends continuously between the first and second notches 12, 12'. More precisely, here, said notch bottom insulator 24 passes opposite a top 32 of said wedging member 18, said top 32 connecting said first and second large faces 20, 20'.

[0030] Said notch bottom insulator 24 advantageously comprises a protrusion 26 emerging from said notch 12, 12' and covering the external longitudinal edge 24 of said notch 12, 12'. Said protrusion 26 extends radially in said insulating groove 22 between said body 2 and said wedging member 18, in particular by being close to and / or in contact with a bottom of said insulating groove 22. It is understood that the correct positioning of the protrusion 26 does not depend or only indirectly on the wedging member 18 but firstly on the correct positioning of the winding(s) 16, 16'.

[0031] Said insulating groove 22 is formed, for example, in said longitudinal portion 10 of the pole heads 8, in particular in the form of a shoulder. Said longitudinal portion 10 here has a lip 28 for contact with said wedging member 18. Said contact lip 20 radially externally closes said insulating groove 22. According to the illustrated embodiment, it bears on an upper face of said wedging member 18.

[0032] One of the rows of said winding 16, 16', called the support row, is in contact with said wedging member 18, in particular by said large face 20, 20' located opposite. In other words, the large face(s) 20, 20' of the wedging member(s) 18 are intended to form a contact zone for said support row.

[0033] It can be seen that the said notch(s) 12, 12' here have an opening 30, the said corresponding winding 16, 16' being flush with the said opening 30 and / or projecting from the said opening 30 towards the said wedging member 18.

[0034] Said support row is formed of portions of the conductor 17, 17' belonging to an outer row of turns of the winding. Here, said support row is located outside said notch 12, 12'. It has a lower number of turns than the other rows.

[0035] Such a configuration makes it possible to provide particularly effective insulation between the body 2 and a portion 34 of the windings 16, 16' located near said external longitudinal edge 24 of the notches 12, 12'. Said portion 34 of the winding corresponds, for example, to one of the strands of the support row, located radially externally in said support row, and / or to one of the strands, called the upper strand, of one, external, of the layers, said upper strand belonging to a row located immediately below said support row.

[0036] The invention further relates to an electrical machine comprising a rotor as described above. Said machine comprises an output shaft, not visible in the figure, secured to said rotor. It could also be, in particular, a synchronous or asynchronous electrical machine.

Claims

Claims

1. Rotor of an electrical machine, in particular an electrical machine of a motor vehicle, said rotor comprising a body (2) electrically connected to a ground and provided with at least one notch (12, 12'), said rotor further comprising at least one winding (16, 16') of an electrical conductor (17, 17') arranged at least partially in said notch (12, 12'), said rotor being configured to electrically insulate said winding (16, 16') from said body (2), said rotor further comprising a wedging member (18), not electrically connected to the ground, and applying the winding (16, 16') in the notch (12, 12'), said winding (16, 16') being in contact with said wedging member (18).

2. Rotor according to the preceding claim comprising an insulating groove (22) between said winding (16, 16') and said body (2), said insulating groove (22) extending radially outwards from an external longitudinal edge (24) of said notch (12, 12').

3. Rotor according to the preceding claim comprising a slot bottom insulator (24), arranged between walls of the slot (12, 12') and said winding (16, 16'), said slot bottom insulator (24) comprising a protrusion (26) emerging from said notch (12, 12') and covering the external longitudinal edge (24) of said notch (12, 12').

4. Rotor according to the preceding claim in which said wedging member (18) is arranged between a first and a second of the windings (16, 16') so as to weave the first winding (16) in a first of said notches (12) and the second winding (16') in a second of said notches (12'), said notch bottom insulator (24) extending continuously between the first and second notches (12, 12').

5. Rotor according to any one of claims 3 or 4 wherein said protrusion (26) extends radially in said isolating groove (22) between said body (2) and said wedging member (18).

6. Rotor according to any one of claims 2 to 5 wherein said body (2) comprises at least one pole (4) provided with a pole foot (6) and a pole head (8) extending radially outwardly from said pole foot (6), said notch (12, 12') being located in the pole foot (6) close to said pole head (8), said pole head (8) angularly projecting from said pole foot (6) by a longitudinal portion (10), said insulating groove (22) being formed in said longitudinal portion (10) of the pole head (8).

7. Rotor according to the preceding claim in which said longitudinal portion (10) has a contact lip (28) with said wedging member (18), said contact lip (28) radially externally closing said isolating groove (22).

8. Rotor according to any one of the preceding claims in which said notch (12, 12') has an opening (30), said winding (16, 16') being flush with said opening (30) and / or projecting from said opening (30) towards said wedging member (18).

9. Rotor according to the preceding claim in which said winding (16, 16') comprises a row, called a support row, formed with said electrical conductor (17, 17'), said support row being in contact with said wedging member (18), said support row being located outside said notch (12, 12').

10. An electrical machine comprising a rotor according to any one of the preceding claims.

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