WO2021249590A1

WO2021249590A1 - Electric motor with receiving pockets for receiving magnets

Info

Publication number: WO2021249590A1
Application number: PCT/DE2021/100402
Authority: WO
Inventors: Jules Etienne Tegueu Simo; Holger Keck; Marcus Scherrer; Yvain-Prince Kouopi; Amelie Magnenet
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2020-06-09
Filing date: 2021-05-04
Publication date: 2021-12-16
Also published as: DE102020115286A1

Abstract

The invention relates to an electric motor (1) for a hybrid or purely electrically driven motor vehicle, comprising a permanently excited rotor (2), wherein the rotor (2) has a main body (3) and a plurality of magnets (6a, 6b, 7) which are received in receiving pockets (4a, 4b, 5) of the main body (3), and wherein in each case two magnets (6a, 6b) which form a magnet pair (8) are arranged in a substantially V-shaped arrangement (9) with one another, wherein each receiving pocket (4a, 4b) of the same magnet pair (8) has a longitudinal section (10) of constant width, which holds the magnets (6a, 6b), and has two widened sections (12, 13), which adjoin the ends (11a, 11b) of the longitudinal section (10) and which are designed to be wider than the longitudinal section (10) at least in sections.

Description

Electric motor with pockets for holding magnets

The invention relates to an electric motor for a hybrid or purely electrically powered motor vehicle, such as a car, truck, bus or other commercial vehicle, with a permanently excited rotor, the rotor having a base body and several magnets received in receiving pockets of the base body, and each two magnets forming a magnet pair are arranged in a substantially V-shaped arrangement / alignment with one another.

Generic electric motors are known, for example, from DE 102014212 871 A1, which discloses a dynamoelectric permanently excited machine.

In the case of the designs known from the prior art, it has been found that the individual receiving pockets greatly reduce the mechanical strength of the rotor. Notches or thin webs / bridges formed by the receiving pockets can be overloaded and damaged in individual operating states.

It is therefore the object of the present invention to provide an electric motor with a permanently excited rotor, the mechanical robustness of which is increased further, the efficiency at least not being adversely affected at the same time.

This is achieved according to the invention in that each receiving pocket of the same pair of magnets has a longitudinal section of constant width holding the magnet and two widening sections adjoining the ends of the longitudinal section, which are at least partially wider than the longitudinal section.

The smallest possible notch effects are generated by receiving pockets shaped in this way, as a result of which the rotor is mechanically much more robust. At the same time, with the mounting pockets, the inertia of the rotor is further reduced, so that the electric motor becomes more powerful. Further embodiments are claimed with the subclaims and explained in more detail below.

Accordingly, it is also advantageous if the magnets of the pair of magnets, which are each aligned along one of the two legs of a V, are arranged in a flat angle to each other. This results in an improvement in the efficiency of the electric motor.

In addition, it is advantageous if the two receiving pockets of the same pair of magnets are designed / arranged in a mirror-inverted manner with respect to a radially extending reference plane. This results in a strength of the rotor independent of the direction of rotation.

In a preferred manner, the main body of the rotor is formed from a stack of laminations comprising a plurality of individual laminations arranged in a stack. This results in a simple manufacture of the rotor. The receiving pockets are punched or cut, for example laser-cut, particularly before given.

It is also advantageous if each receiving pocket of the same pair of magnets has a first widening section adjoining in the radial direction within the longitudinal section, which first widening section extends away from the longitudinal section in a substantially U-shape. This results in a transition with as little mechanical stress as possible, with which at the same time as much material as possible is removed to reduce the inertia.

In this context, it has also been found to be useful if the first widening sections of the two receiving pockets of the same pair of magnets extend away from one another in the circumferential direction relative to one another towards their end facing away from the longitudinal section.

Furthermore, it is advantageous if each receiving pocket of the same pair of magnets has a second adjacent in the radial direction outside the longitudinal section Has widening section, which second widening section is positioned and running relative to a radial outer circumferential surface of the base body such that a web area remaining radially between the outer circumferential surface and the second widening section has a smaller width than the longitudinal section. As a result, the magnets are displaced as far as possible in the radial direction towards the air gap formed between a stator and the rotor during operation.

It is also useful if in the circumferential direction (preferably in the center) between tween the two receiving pockets of the same pair of magnets (and radially outside half of the pair of magnets) another magnet is used. This further magnet preferably forms a triangular arrangement with the magnets of the magnet pair, with each of the three magnets also forming one side of the triangle. The further magnet is thus preferably arranged / aligned to run in the circumferential direction. This results in an even more powerful electric motor.

It is also advantageous if a plurality of holes is present radially within the receiving pockets of the magnet pairs, which holes are strung together to form a perforated ring structure. As a result, a radially within the Aufnah metaschen specifically intended to reduce the inertia area will create ge.

In order to ensure the necessary strength of the rotor, it is advantageous if an annular web extending continuously in the circumferential direction is arranged directly ra dial inside and / or outside the plurality of holes.

In other words, according to the invention, a magnetic pocket (on receiving pocket) of the rotor of a permanently excited synchronous motor with a triangular magnet arrangement is realized. The magnetic pockets are specially shaped for optimized electromagnetic properties and for optimal structural rigidity of the rotor.

The invention will now be explained in more detail below with reference to figures, in which context various exemplary embodiments are also shown. Show it:

Fig. 1 is a front view of an electric motor according to the invention according to a first embodiment, wherein several receiving pockets introduced in a base body of the Ro tor and holes in shape and distribution can be clearly seen,

FIG. 2 shows a detailed representation of a circumferential section of the rotor of FIG. 1,

Fig. 3 is a front view of a rotor of an electric motor according to the invention according to a second embodiment, which differs from the first game Ausführungsbei with regard to the Ausfor determination of the receiving pockets and holes, and

FIG. 4 shows a detailed illustration of a circumferential area of the rotor according to FIG. 3.

The figures are only of a schematic nature and are used exclusively for understanding the invention. The same elements are provided with the same reference numerals.

With Fig. 1, the structure of an electric motor 1 according to the invention can be clearly seen on the basis of a first exemplary embodiment. The electric motor 1 is implemented as a permanently excited synchronous machine. A stator 20 fixed to the housing is indicated schematically in FIG. 1. Radially within the annular stator 20, a permanently magnetized rotor 2 is arranged to be rotatable about an axis of rotation 21. The electric motor 1 is preferably designed for use in a dedicated hybrid transmission.

The direction details used below, axial / axial direction, radial / radial direction and circumferential direction, relate to the axis of rotation 21. Accordingly, an axial direction is a direction along the axis of rotation 21 (ie in FIG. 1 in the Plane in), a radial direction, a direction perpendicular to the axis of rotation 21 and a circumferential direction, a direction along a coaxially to the axis of rotation 21 extending circular line with a constant diameter.

The rotor 2 has a base body 3. The base body 3 is in turn formed from a laminated core. The base body 3 thus has a plurality of individual metal sheets 22 which are arranged axially stacked with respect to one another, one of these individual metal sheets 22 can be seen in FIG. 1 from the top view. The individual sheets 22 are re alized as identical parts and therefore all of the same design. The shape of the individual metal sheets 22 consequently corresponds to the shape of the base body 3 described below.

A plurality of magnets 6a, 6b and 7 designed as permanent magnets are accommodated in the base body 3. It can be seen that a group of three magnets 6a, 6b and 7, that is to say a first magnet 6a, a second magnet 6b and a third magnet 7, is provided several times in the circumferential direction. In this exemplary embodiment, eight of these groups are evenly distributed over the circumference.

The three magnets 6a, 6b and 7 belonging to a group describe a triangular shape with their arrangement. H. have a triangular arrangement. Accordingly, there are a first magnet 6a and a second magnet 6b for forming a pair of magnets 8, this pair of magnets 8 being a V-shaped arrangement 9. The first magnet 6a is consequently aligned along a first leg of a V and the second magnet 6b along a second leg of the V. The two first and second magnets 6a, 6b are also arranged mirror-symmetrically / mirror-inverted with respect to an exclusively radially extending reference plane 14. The first magnet 6a and the second magnet 6b form a flat angle to one another.

The third magnet 7 is arranged in the circumferential direction centrally between the first magnet 6a and the second magnet 6b. The third magnet 7 is aligned in the circumferential direction Rich. As a result, the magnets 6a, 6b, 7 form a triangular shape pointing radially inward with their tip. With regard to the two magnets 6a, 6b of the magnet pair 8, it can be seen that they are received by two essentially identically shaped receiving pockets 4a, 4b. The first receiving pocket 4a and the second receiving pocket 4b have the shape that can be seen in the plane of the drawing according to FIG. For the sake of brevity, only the formation of the first receiving pocket 4a and the reception of the first magnet 6a in this first receiving pocket 4a will be described below, which, however, also apply to the second receiving pocket 4b and the reception of the second magnet 6b in this second receiving pocket 4b .

The first receiving pocket 4a has a substantially rectilinear longitudinal section 10 with a constant width. The first magnet 6a rests directly on the sides of this longitudinal section 10 and is thereby fixed in the sense of a press bond. The longitudinal section 10 closes with one radial end 11a each,

11 b a widening section 12, 13.

A first widened section 12 is that widened section which connects to a first end 11 a of the longitudinal section 10 pointing inward in the radial direction. This first widening section 12 is implemented essentially U-shaped / sack-shaped when viewed in cross section / top view according to FIG. It can be seen that the first widened section 12, with its area directly adjoining the longitudinal section 10, has a greater width than the longitudinal section 10. The first widened section 12 extends essentially U from the side of the first widened section 12 facing the longitudinal section 10 -shaped away. It can be seen that the first widening sections 12 of the two receiving pockets 4a, 4b of the same pair of magnets 8 extend away from one another in the circumferential direction towards their free end.

A second widened section 13 is that widened section which connects to a second end 11 b of the longitudinal section 10 pointing outward in the radial direction. This second widening section 13 also has with his The region directly adjoining the longitudinal section 10 has a greater width than the longitudinal section 10. In this context, it should be pointed out that the first magnet 6a has a length such that it also at least partially protrudes into the first and second widening sections 12, 13.

The second widened section 13 extends in the radial direction and in the circumferential direction away from the longitudinal section 10 in such a way that a web area 16 remains between a radial outer circumferential surface 15 of the base body 3 and the second widened section 13, which has a smaller width than the longitudinal section 10 / the first magnet 6a.

The respective receiving pocket 4a, 4b thus has an essentially phallus-shaped contour.

The third magnet 7 is arranged in a third receiving pocket 5 in the circumferential direction between the two receiving pockets 4a, 4b. This third receiving pocket 5 has a substantially I-shaped contour and is aligned in the circumferential direction. The third receiving pocket 5 preferably has a retaining lug 23 on each peripheral side of the third magnet 7, more preferably on a radial inner side, so that the third magnet 7 is fixed in the peripheral direction.

As can also be seen, the base body 3 has a plurality of further holes 17a, 17b, 17c, 17d and 17e. The holes 17a to 17d form a perforated ring structure 18 which runs continuously in the circumferential direction. A continuously running (second) ring web 19b is arranged radially within this ring structure 18 and a continuously running (third) ring web 19c is arranged radially outside of this ring structure 18. A first annular web 19a is adjacent to the outer jacket surface 15 and is thus implemented radially between the receiving pockets 4a, 4b, 5 and the outer jacket surface 15.

It can be seen that the first and second holes 17a and 17b are essentially kidney-shaped or potato-shaped holes. The holes 17a, 17b are Arranged in pairs and also form a substantially V-shaped arrangement. In the circumferential direction between these two holes 17a and 17b there is a (fourth) hole 17d which is configured somewhat smaller than the holes 17a, 17b. A third hole 17c is positioned next to the first hole 17a in the circumferential direction and has a smaller shape than the fourth hole 17d. The four holes 17a to 17d in turn form a group of holes that are lined up repeatedly in the circumferential direction to form the ring structure 18.

It can also be seen that a fifth hole 17e is present in the radial direction at the level of the first widening sections 12 and in the circumferential direction essentially centrally between the first widening sections 12 of two adjacent magnet pairs 8. This fifth hole 17e has a circular contour.

With the FIGS. 3 and 4 then a further second exemplary embodiment is shown, which is constructed and functions essentially in accordance with the first exemplary embodiment. For the sake of brevity, therefore, only the differences from the first exemplary embodiment are described below.

It can be seen that the third magnet 7 has a smaller thickness / width than the two first and second magnets 6a, 6b. Accordingly, the third receiving pocket 5 is thinner / less wide than the two receiving pockets 4a, 4b implemented.

It can also be seen that the first and second widening sections 12, 13 are implemented somewhat smaller, but again increase the width of the longitudinal section 10.

Furthermore, there are only two different holes 17a, 17b, which in turn form a group of holes that are repetitive in the circumferential direction to form a ring structure 18. The first holes 17a extend in the radial direction into a circumferential area between the receiving pockets 4a, 4b of two adjacent magnet pairs 8. This only results in two ring webs running continuously in the circumferential direction in the form of the first ring web 19a and the second ring web 19b.

In other words, according to the invention, the magnetic pockets 4a, 4b are designed phallus-shaped in order to meet both the electromagnetic and mechanical requirements. Existing recesses 17a, 17b, 17c, 17d, 17e under the magnet pockets 4a, 4b are designed in such a way that both the requirements for the overlap between the rotor 2 and the shaft and for the inertia are met.

Bezuqszeichenliste electric motor rotor base body a first receiving pocket b second receiving pocket third receiving pocket a first magnet b second magnet third magnet magnet pair arrangement 0 longitudinal section 1 a first end 1 b second end 2 first widening section 3 second widening section 4 reference plane 5 outer jacket surface 6 web area 7a first hole 7b second hole 7c third hole 7d fourth hole 7e fifth hole 8 ring structure 9a first ring web 9b second ring web 9c third ring web 0 stator 1 axis of rotation 2 single sheet 3 retaining lug

Claims

1. Electric motor (1) for a hybrid or purely electrically powered motor vehicle, with a permanently excited rotor (2), the rotor (2) having a base body (3) and several in receiving pockets (4a, 4b, 5) of the base body ( 3) has accommodated magnets (6a, 6b, 7), and wherein two magnets (6a, 6b) forming a pair of magnets (8) are arranged with one another in a substantially V-shaped arrangement (9), characterized in that Each receiving pocket (4a, 4b) of the same pair of magnets (8) has a longitudinal section (10) of constant width holding the magnet (6a, 6b) and two widening sections (12, 13) adjoining the ends (11a, 11b) of the longitudinal section (10) which are at least partially wider than the longitudinal section (10), has.

2. Electric motor (1) according to claim 1, characterized in that the receiving pockets (4a, 4b) of the same pair of magnets (8) are mirror-inverted in relation to a radially extending reference plane (14).

3. Electric motor (1) according to claim 1 or 2, characterized in that each receiving pocket (4a, 4b) of the same pair of magnets (8) has a radial direction within the longitudinal section (10) adjacent first Verbrei sion section (12), which is located in Extends substantially in a U-shape from the longitudinal section (10).

4. Electric motor (1) according to claim 3, characterized in that the first widening sections (12) of the two receiving pockets (4a, 4b) of the same magnet pair (8) extend away from one another in the circumferential direction relative to one another to their end facing away from the longitudinal section (10) .

5. Electric motor (1) according to one of claims 1 to 4, characterized in that each receiving pocket (4a, 4b) of the same pair of magnets (8) has a second widening section (13) adjoining in the radial direction outside the longitudinal section (10), which is in such a way is positioned relative to a radial outer lateral surface (15) of the base body (3) and ver runs that one radially between the outer lateral surface (15) and the second The widening section (13) of the remaining web area (16) has a smaller width than the longitudinal section (10).

6. Electric motor (1) according to one of claims 1 to 5, characterized in that a further magnet (7) is inserted in the circumferential direction between the two receiving pockets (4a, 4b) of the same magnet pair (8).

7. Electric motor (1) according to one of claims 1 to 6, characterized in that radially inside the receiving pockets (4a, 4b) of the magnet pairs (8) a plurality of holes (17a, 17b, 17c, 17d) are present, which holes (17a, 17b, 17c, 17d) are strung together to form a perforated ring structure (18).

8. Electric motor (1) according to claim 7, characterized in that directly ra dial inside and / or outside the plurality of holes (17a, 17b, 17c, 17d) is arranged a continuously extending annular web (19b, 19c) in the circumferential direction.