FR3062755A1 - IMPROVED ASSEMBLY OF ROTOR OF ROTATING ELECTRICAL MACHINE - Google Patents

Abstract

The invention relates mainly to a rotor (12) of a rotating electric machine for a motor vehicle, characterized in that it comprises: a body (23) formed by a bundle of sheets (30) made of a magnetic material, in particular a plurality of permanent magnets (24) housed in cavities (25) of the body (23), two non-magnetic steel flanges (27, 28) disposed at each axial end of the body (23), a plurality fasteners (35), each fastener (35) passing through both the flanges (27, 28) and the body (23) to hold the flanges (27, 28) and the plates (30) together. pack of sheets.

Description

Holder (s): VALEO ELECTRIC EQUIPEMENTS MOTOR Simplified joint-stock company.

Extension request (s)

Agent (s): VALEO EQUIPEMENTS ELECTRIQUES MOTOR Simplified joint-stock company.

IMPROVED ASSEMBLY OF A ROTOR OF A ROTATING ELECTRIC MACHINE.

FR 3 062 755 - A1

The invention relates mainly to a rotor (12) of a rotary electrical machine for a motor vehicle, characterized in that it comprises:

a body (23) formed by a pack of sheets (30) made of a magnetic material, in particular steel,

- a plurality of permanent magnets (24) housed in cavities (25) of the body (23),

- two non-magnetic steel flanges (27, 28) disposed at each axial end of the body (23),

- A plurality of fixing members (35), each fixing member (35) passing through both the flanges (27, 28) and the body (23) to hold the flanges (27, 28) and the sheets together ( 30) of the sheet pack.

IMPROVED ASSEMBLY OF A ROTOR OF A ROTATING ELECTRIC MACHINE

The present invention relates to an improved assembly of a rotor of a rotary electrical machine. The invention finds a particularly advantageous, but not exclusive, application with reversible high-power electric machines capable of operating in alternator mode and in motor mode coupled with a host element, such as a gearbox.

In a manner known per se, rotary electrical machines comprise a stator and a rotor secured to a shaft. The rotor may be integral with a driving and / or driven shaft and may belong to a rotating electrical machine in the form of an alternator, an electric motor, or a reversible machine capable of operating in both modes.

The stator is mounted in a casing configured to rotate the shaft on bearings by means of bearings. The rotor comprises a body formed by a stack of sheets of metal sheets held in the form of a package by means of a suitable fixing system.

The stator comprises a body constituted by a stack of thin sheets forming a crown, the inner face of which is provided with notches open towards the inside to receive phase windings. These windings pass through the notches in the stator body and form buns protruding from either side of the stator body. The phase windings are obtained for example from a continuous wire covered with enamel or from conductive elements in the form of pins connected together by welding. These windings are polyphase windings connected in star or triangle whose outputs are connected to an inverter also operating as a rectifier bridge.

Furthermore, the rotor may include a body formed by a pack of sheets made of a magnetic material, in particular steel, as well as poles formed by a plurality of permanent magnets housed in cavities of the body. In addition, two flanges are arranged at each axial end of the body to ensure the retention of the magnets.

The flanges are generally aluminum flanges fixed by screwing on the axial end faces of the rotor body. Such a configuration, however, has an axial size and a significant weight.

The present invention aims to effectively remedy this drawback by proposing a rotor of a rotating electric machine for a motor vehicle, characterized in that it comprises:

a body formed by a pack of sheets made of a magnetic material, in particular steel,

- a plurality of permanent magnets housed in body cavities,

- two non-magnetic steel flanges placed at each axial end of the body,

- A plurality of fixing members, each fixing member passing through both the flanges and the body to hold the flanges and the sheets of the sheet pack together.

The invention thus makes it possible, thanks to the assembly of the rotor by means of fixing members passing through the rotor body and flanges assembly, to reduce the axial length as well as the weight of the rotor. Such an assembly is made possible by the fact that there is a steel / steel interface between the rotor and the flanges thus reducing the risk of deformation during the expansion of the assembly while deformations are observed during applying a tightening torque to a standard flange made of aluminum.

According to one embodiment, the sheets of the sheet pack are glued together.

This makes it easier to handle the package during transport before final assembly with the flanges and the shaft.

According to one embodiment, the fixing members are rivets.

According to one embodiment, the fixing members are made of a magnetic material.

According to one embodiment, the fixing members are made of a non-magnetic material.

According to one embodiment, the rotor body and the flanges have a central opening for the passage of a shaft.

According to one embodiment, said rotor is of the flux concentration type. The permanent magnets are then installed radially or in a V-shaped configuration inside the sheet pack.

According to one embodiment, the permanent magnets extend ortho-radially inside the cavities of the rotor body.

According to another aspect, the invention relates to a rotary electric machine characterized in that it comprises a rotor as defined previously.

The invention will be better understood on reading the description which follows and on examining the figures which accompany it. These figures are given only by way of illustration but in no way limit the invention.

Figure 1 is a longitudinal sectional view of a rotary electric machine according to the present invention;

Figure 2 is a perspective view of the rotor according to the present invention mounted on a shaft of the rotary electrical machine without the flanges holding the magnets;

FIG. 3 is a perspective view of the rotor according to the present invention mounted on a shaft of the rotary electric machine with the flanges holding the magnets;

Figure 4 is a detailed perspective view of the rotor illustrating the configuration of a flange according to the present invention;

Figures 5a and 5b are perspective views of the front and rear flanges of the rotor according to the present invention, respectively.

Identical, similar, or analogous elements retain the same reference from one figure to another.

In the following description, the term “front element” means an element situated on the side of the pinion carried by the machine shaft and “rear element” means an element situated on the opposite side.

FIG. 1 shows a rotary electrical machine 10 comprising a stator

11 polyphase surrounding a rotor 12 mounted on a shaft 13 of axis X. The stator surrounds the rotor 12 with the presence of an air gap between the internal periphery of the stator 11 and the external periphery of the rotor 12. The stator 11 is mounted in a casing 14 provided with a front bearing 17 and a rear bearing 18 carrying the shaft 13 in rotation. For this purpose, bearings 15 are interposed between the shaft 13 and the bearings 17, 18. The bearing 15 shown in FIG. 3 is associated with a target holder 21 integral with the internal ring of the bearing 15 to allow monitoring of the angular position of the rotor 12.

This electric machine 10 can be coupled, via a pinion 16, to a gearbox belonging to a traction chain of a motor vehicle. In order to ensure a rotational connection between the shaft 13 and the pinion 16, a grooved assembly 22 of complementary shape may take place between these two elements, as shown in FIGS. 2 and 3.

The machine 10 is capable of operating in an alternator mode in particular to supply energy to the battery and to the on-board network of the vehicle, and in an engine mode, not only to ensure the starting of the heat engine of the vehicle, but also for participate in vehicle traction alone or in combination with the heat engine. The power of the machine 10 can be between 15kW and 50kW.

More specifically, the stator 11 comprises a body 19 constituted by a pack of sheets as well as a coil 20. The body 19 is formed by a stack of sheets of sheets held in the form of a pack by means of a suitable fixing system. This body 19 is provided with teeth defining two by two of the notches for mounting the winding 20.

The winding 20 comprises a set of phase windings passing through the notches and forming buns projecting on either side of the stator body 19. The phase windings are obtained here from shaped conductive elements pins connected to each other, for example by welding. These windings are for example three-phase windings connected in a star or a triangle. The outputs of the phase windings are connected to an inverter which can also operate if necessary as a rectifier bridge.

Furthermore, as illustrated in FIGS. 2, 3 and 4, the rotor 12 comprises a body 23 formed by a pack of sheets made of a magnetic material, in particular steel, as well as a plurality of permanent magnets 24 housed in cavities 25 of the body 23. Two flanges 27, 28, advantageously made of non-magnetic steel, are arranged at each axial end of the body 23, as shown in FIG. 3.

Preferably, the sheets 30 of the pack of sheets stacked axially can be glued together in order to facilitate handling of the pack during transport before final assembly with the flanges 27, 28 and the shaft 13.

The permanent magnets 24 can be installed inside the cavities

25 in a V-shaped configuration (see FIG. 2) or be located radially inside the sheet pack 23, the side faces facing two consecutive magnets 24 being of the same polarity. The rotor 12 is then of the flux concentration type.

Alternatively, the permanent magnets 24 extend ortho-radially inside the cavities 25 of the body 23. The magnets 24 may be made of rare earth or ferrite depending on the applications and the desired power of the machine 10.

The rotor body 23 and the flanges 27, 28 each have a central opening 31 for the passage of the shaft 13. This shaft 13 has a section fitted into the opening of the rotor body 23 in order to link the rotation body rotor 23 to shaft 13.

In addition, as can be seen in FIG. 3, the flanges 27, 28 and the rotor body 23 have fixing through holes 34 allowing passage of the corresponding fixing members 35. The fixing holes 34 of the rotor body 23 are located in coincidence with the fixing holes 34 of the corresponding flanges 27, 28.

Each fixing member 35 passes axially through both the flanges 27, 28 and the body 23 to hold the flanges 27, 28 and the sheets 30 of the body 23 together.

Preferably, the fixing members 35 are rivets. The rivets 35 take the form of an elongated rod provided with a head at one of its ends. The other end of the rod may be crushed, for example by bolting after having been threaded through the flange assembly 27, 28 and rotor body 23. As a variant, the free end is threaded and the flange assembly 27, 28 and rotor body 23 is held by means of a nut screwed to the threaded end. The fixing members 35 are made of a magnetic material or of a non-magnetic material.

Furthermore, as can be seen in FIGS. 4, 5a, and 5b, each flange 27, 28 comprises a plurality of guide holes 37 passing through made in advance in the flanges 27, 28 to allow passage of a tool, of the drill type, suitable for producing a blind balancing hole 38 opening onto an axial end face of the body 23.

In this case, the guide holes 37 are arranged along the same circumference and spaced angularly between them in a regular manner. The guide holes 37 are made according to a diameter smaller than that along which the fixing holes 34 are made. Any other arrangement of the guide holes 37 adapted to the application could however be envisaged.

Depending on the balancing need, certain guide holes 37 among the assembly will be used to make matching blind holes 38 in the rotor body 23, as shown in FIG. 4.

Thus, once the rotor 12 has been balanced, each balancing hole 38 is coaxial with the corresponding guide hole 37. Furthermore, of all of the guide holes 37, only a part opens into a corresponding balancing hole 38, the other guide holes 37 not having been used for balancing the rotor 12.

The balancing holes 38 are located on each axial side of the rotor body 23 while being diametrically opposite to those made on the other axial side of the rotor body 23.

The flanges 27, 28 also preferably include an indexing means 40 to be angularly indexed relative to the body 23 of the rotor 23. When the flange 27, 28 and the body 23 are angularly indexed relative to each other , the axes Y of the guide holes 37 cut the body 23 outside the cavities 25 for receiving the magnets 24. This makes it possible to avoid damaging the permanent magnets 24 when drilling the balancing holes 38.

The indexing means 40 is preferably constituted by the fixing holes 34 allowing the passage of the rivets 35 for fixing the flanges 27, 28 to the rotor body 23. In fact, when the fixing holes 34 are crossed by the corresponding fixing members 35, a correct angular positioning of the flanges 27, 28 is guaranteed, avoiding interference between the balancing holes 38 and the permanent magnets 24.

As shown in FIG. 5a, the front flange 27 may also include shapes 41 for receiving the springs holding the permanent magnets 24.

As a variant, the means for guiding the tool for producing the balancing holes 38 may consist of marks made on an external face of the flanges 27, 28.

Of course, the foregoing description has been given by way of example only and does not limit the scope of the invention from which one would not depart by replacing the various elements with any other equivalent.

Furthermore, the various features, variants, and / or embodiments of the present invention can be combined with one another in various combinations, insofar as they are not incompatible or mutually exclusive of one another.

Claims (3)

1. Rotor (12) of a rotary electrical machine (10) for a motor vehicle, characterized in that it comprises: - a body (23) formed by a pack of sheets (30) produced in a 5 magnetic material, in particular steel, - a plurality of permanent magnets (24) housed in cavities (25) of the body (23), - two flanges (27, 28) in non-magnetic steel disposed at each axial end of the body (23), îo - a plurality of fixing members (35), each fixing member (35) passing through both the flanges (27 , 28) and the body (23) for holding the flanges (27, 28) and the sheets (30) of the sheet pack together. 2. Rotor according to claim 1, characterized in that the sheets (30) of the sheet pack are bonded together. 3. Rotor according to claim 1 or 2, characterized in that the fixing members (35) are rivets. 4. Rotor according to any one of claims 1 to 3, characterized in that the fixing members (35) are made of a magnetic material. 5. Rotor according to any one of claims 1 to 3, characterized in that the fixing members (35) are made of a non-magnetic material. 6. Rotor according to any one of claims 1 to 5, characterized in that the rotor body (23) and the flanges (27, 28) have a 25 central opening (31) for the passage of a shaft (13). 7. Rotor according to any one of claims 1 to 6, characterized in that it is of the flux concentration type. 8. Rotor according to any one of claims 1 to 6, characterized in that the permanent magnets (24) extend ortho-radially inside the cavities (25) of the rotor body (23). 9. Rotating electric machine (10) characterized in that it comprises a rotor (12) as defined according to any one of the preceding claims. 1/3 2/3 Y 40 3/3