WO2024017874A1

WO2024017874A1 - Electric motor unit and sliding roof unit comprising such an electric motor unit

Info

Publication number: WO2024017874A1
Application number: PCT/EP2023/069882
Authority: WO
Inventors: Rajesh JAYARAJ; Levente GYERKO; Camille Bitenc
Original assignee: Webasto SE
Priority date: 2022-07-18
Filing date: 2023-07-18
Publication date: 2024-01-25
Also published as: DE102022117858A1

Abstract

The invention relates to a stator unit (1) for an electric motor, in particular for a brushless electric motor, having multiple stator windings (20) and having a surrounding base structure (10) for receiving the multiple stator windings (20), wherein mutually facing peripheral surfaces (24) of mutually adjacent stator windings (20) are parallel to one another. The invention furthermore relates to an electric motor having such a stator unit.

Description

Electric motor unit and sunroof unit with such

Description

The invention relates to an electric motor unit, in particular a brushless electric motor unit, for a sunroof unit and a sunroof unit with such an electric motor unit.

In motor vehicles, direct current motors (DC motors) with a brush and a commutator are usually used as drives for sunroofs or sliding roofs and the like. Furthermore, existing electric motors have an outer diameter of up to 40 mm and provide speeds of approximately 6,900 to 10,000 rpm for sufficient operation of sunroofs.

The use of brushes and commutators leads to an unpleasant background noise in a high-frequency range, for example 3-5 KHz. The (permanent) magnets of the rotor are usually arranged in an inclined position in order to reduce or optimize the cogging torque of the electric motor and thus also achieve a noise reduction.

Nevertheless, the use of such electric motors is subject to strict requirements in order to avoid such unpleasant operating noises for the vehicle's occupants. Furthermore, the DC motors require more installation space in order to be able to meet the necessary performance requirements. The use of brushes limits the lifespan of the electric motor, with the usual running times for such electric motors or brushes being around 150 working hours. In the area of motor vehicles, among other things, a longer overall running time is necessary in order to be able to do justice to the service life of the motor vehicle.

The invention is based on the object of specifying an electric motor unit which provides optimized handling with improved running and operating properties, allows simplified production and can be produced cost-effectively, in particular the energy efficiency and noise development should be able to be optimized. Furthermore, it is the object of the invention to provide a sunroof unit with such an electric motor unit.

According to the invention, this object is achieved with regard to the electric motor unit by the subject matter of claim 1 and with regard to the sunroof unit by the subject matter of claim 13. Preferred embodiments are specified in the dependent claims.

According to the present invention, an electric motor unit, in particular a brushless electric motor unit, is provided for a sunroof unit with a stator unit and a rotor unit, the stator unit being designed with a surrounding basic structure and a plurality of stator teeth for receiving a plurality of stator windings, so that six slot sections between the stator teeth be formed. Furthermore, the rotor unit is designed with eight magnetic poles.

The invention is based on the basic idea that the electric motor unit with a specific ratio of slot sections and poles can provide reduced noise generation, furthermore optimizing the magnetic flux/magnetic flux density along the stator unit, in particular within the basic structure, in order to achieve improved running properties and an optimized service life to be able to provide. In particular, the stator unit according to the invention is intended for a brushless electric or direct current motor which has a centrally arranged rotor unit, so that the stator unit surrounds the rotor unit along its circumference.

In particular, a longer running time of the electric motor can be achieved. Furthermore, operating noise can be kept constantly low over the entire service life of the electric motor unit, since no wear can occur, for example on a brush or the like.

For the purposes of the present invention, an encompassing basic structure is to be understood in particular as meaning that the stator unit can surround an associated rotor unit, so that the rotor unit is arranged centrally within the stator unit. In this sense, the basic structure of the stator unit can be understood as a frame or the like. The basic structure can be made in one piece or in several parts. The comprehensive character of the basic structure can also be provided by several parts assembled or specifically positioned relative to one another.

Furthermore, it is possible for the basic structure of the stator unit to be formed or covered with an additional insulating layer.

The specific shape and arrangement of the stator windings or magnetic coils also requires an advantageously uniform and sinusoidally undulating cogging torque, particularly in combination with bound (permanent) magnets of a corresponding or associated rotor unit.

For the purposes of the present invention, the plurality of stator windings can be understood to mean in particular a plurality of stator coils, each of which can have several (individual) windings to form a magnetic coil.

The specific ratio of eight magnetic poles and six slot sections or six stator teeth with stator windings, which are each spaced apart from one another via slot sections, results in particular in an advantageously reduced noise development and in a cogging torque that can be optimized. In particular, the overall flux density of the electric motor can be increased based on the specific ratio of eight magnetic poles and six slot sections or six stator teeth with stator windings, which are each spaced apart from one another via slot sections.

It may also be possible to minimize the number of individual windings of each stator winding or magnetic coil and, as a result, to reduce both the total copper weight and the resulting material costs.

According to a preferred embodiment, the rotor unit for forming the magnetic poles has a plurality of magnets, in particular four permanent magnets, the magnets preferably being designed as bonded magnets.

In particular, the balance of the resulting electric motor unit can be adjusted comparatively precisely due to the bound design of the magnets of the rotor unit. Tolerances of 50 pm, and in particular less than 50 pm, can preferably be maintained.

In this way, imbalance of the rotor can be avoided and an optimized balance of the motor can be achieved. The electric motor runs more smoothly and produces less noise during operation.

In addition, it is possible to prevent damage to the magnets, e.g. chipping or breaking, based on the bonded design and the overall size of the individual magnets.

Furthermore, the weight of the electric motor can be reduced due to the bonded design of the rotor magnets.

Likewise, the manufacturing costs can be reduced by the bonded design of the rotor unit, especially compared to so-called surface permanent magnet motors (SPM), which have permanent magnets glued (individually) to the rotor. According to one embodiment, each of the stator teeth has a central axis, relative to which the respective stator winding is designed symmetrically. The individual stator teeth can each have at least one tooth bar, at least one head surface and a bottom surface.

According to the present invention it is provided that each individual stator winding is designed symmetrically with respect to its own central axis.

In this way, a uniform or uniform running characteristic can be achieved for a resulting electric motor, in particular a uniform or uniform, sinusoidal cogging torque.

Starting from the surrounding basic structure, the stator teeth extend in a central direction. The tooth heads are therefore each formed or arranged at a centrally located end of the stator teeth.

In particular, the individual stator windings are each designed geometrically in such a way that the installation space along the individual stator teeth and the respective associated tooth tips is optimally utilized, preferably for arranging a maximum number and/or density of individual windings.

In this sense, the individual stator teeth can have a T-shaped basic shape. As a result, targeted and efficient shaping and guidance of the magnetic flux lines generated by the stator windings can be provided and ensured.

In a preferred embodiment, the respective bottom surface of the individual stator teeth forms an obtuse angle o, preferably an angle between 90° and 160°, between 110° and 150° or between 120° and 140°, in particular 127°, with respect to the central axis of the respective one stator tooth. Furthermore, an edge guide between the respective bottom surface and the respective head surface can preferably have a radius between 0.05 and 1.0 mm, between 0.1 to 0.5 mm, between 0.15 and 0.3 mm or 0.2 mm , exhibit.

A bottom surface is in particular a side of the stator tooth or a tooth head that faces the stator winding. The head area describes the center or the side of the stator tooth or tooth head facing the interior of the electric motor unit.

An edge guide between the bottom and head surfaces of the stator tooth can in particular be a rounded edge which is formed along one end of the head and/or bottom surfaces. Accordingly, the top and bottom surfaces do not necessarily have to abut each other along the edge guide. Rather, an additional side surface can be formed between the head surface and the bottom surface, which collides with the bottom surface or the head surface along the edge guide.

By means of a specific obtuse angle, in particular of 127°, and/or an edge radius along the edge guide at a lateral end of the stator tooth of 0.2 mm, an advantageous distribution and guidance of the magnetic flux lines can be provided.

According to a further preferred embodiment, a peripheral surface of the individual coil windings forms an acute angle β, preferably an angle between 5° and 70°, between 10° and 45° or between 20° and 40°, in particular 30°, with respect to the central axis of the corresponding one stator tooth.

A circumferential surface or a lateral surface of the individual stator windings describes the outer or lateral surface of the preferably (rotationally) symmetrical stator or coil windings, each with a large number of wire or individual windings.

In particular, the angled design of the peripheral surface allows the slot sections between the stator teeth to be formed or continued between the peripheral surfaces. This allows the magnetic flux lines to be guided and designed advantageously.

According to one embodiment, the minimum width of the slot sections is between 1 mm and 10 mm, between 2 mm and 5 mm or between 2.5 mm and 3 mm, in particular 3 mm. Furthermore, according to a further embodiment, it is preferably provided that each of the toothed bars has a toothed width or has a tooth diameter between 0.5 mm and 10 mm, preferably between 1 mm and 5 mm, between 1.5 mm and 3.5 mm or between 1.8 mm and 2.5 mm, in particular 2.5 mm having.

In terms of the preferred width dimension of the slot sections of 3 mm between adjacent stator teeth or tooth heads as well as coil/stator windings or magnet coils, an optimized overall flux density and an optimized cogging torque can be achieved.

Furthermore, the slot sections, including the distances between the circumferential surfaces of the individual stator windings, allow the stator windings in the basic structure to be wound directly onto the stator teeth, preferably with a tool that engages in the slot sections. In this way, simplified production of the electric motor unit can be ensured.

Furthermore, the tooth width or the tooth diameter of preferably 2.5 mm allows a further optimization of the overall flux density or the flux density along each individual stator winding or magnetic coil.

In particular, uniform or uniform gaps can be formed between the individual stator windings arranged next to one another. In this way, improved operating and manufacturing properties of a resulting electric motor unit can be ensured.

By optimizing the efficiency of the individual stator windings and the stator windings as a whole, the number of individual windings required for the respective stator winding or magnetic coil can also be reduced. A reduced number of individual windings to achieve a specific power value, in particular a specific flux density, allows copper to be saved and thus a cost-optimized and space-optimized design of the stator unit.

In one embodiment, the basic structure of the stator unit has a hexagonal shape, in particular a hexagonal outer shape. Furthermore, according to one embodiment, it can be provided that the stator unit, in particular the basic structure of the stator unit, has an external width of 33.8 mm. It is preferably provided that the stator teeth are formed along the longitudinal sections of the hexagonal basic structure, in particular centrally along the individual longitudinal sections.

Thus, a number of stator windings or magnetic coils that preferably corresponds to the hexagonal basic structure is provided.

Because the stator teeth are designed to be equidistant, i.e. at the same distance from one another, a constant force effect on the associated rotor unit is possible along the entire circumference of the stator unit.

The basic structure of the stator unit preferably has a hexagonal (progressive) shape or (progressive) geometry, with the outer width in the sense of the present invention being determined based on the distance between opposing longitudinal sections.

Compared to a round design or a round-shaped base body of the stator unit, a space-saving design can advantageously be achieved using the hexagonal geometry. Furthermore, a greater power density of the electric motor can be achieved in this way.

According to a further preferred embodiment, opposing peripheral surfaces of adjacent stator windings or stator coils, in particular cross-sectional edges of the peripheral or lateral surfaces of the stator windings arranged next to one another, are designed parallel to one another.

In particular, the (cross-sectional) edges of the circumferential or lateral surfaces of the stator windings, which are opposite one another in a cross section of the stator windings, can therefore each be aligned parallel to one another.

On the basis of such a parallel design or alignment of the stator windings facing each other, a uniform or evenly extending gap is formed between the individual stator windings or stator coils.

According to a further embodiment it is provided that a head receptacle with a plurality is arranged at a longitudinal end of the stator unit on retaining webs and a plurality of retaining teeth, with at least one cable of the electric motor unit, in particular for electrically connecting the stator windings, being guided along an inner side of the retaining webs and each on an outside of the retaining teeth.

In this way, a safe or secured and at the same time space-saving cable routing can be provided on one end side of the stator unit in order to ensure a power supply, in particular for the coil windings.

According to a secondary aspect of the invention, a sunroof unit for a vehicle, in particular a motor vehicle, is provided with an electric motor unit according to the present invention.

In this way, reduced noise can be ensured during operation of the sunroof, in particular in order to increase the comfort of the vehicle occupants. An optimized cogging torque, an improved running time and optimized energy efficiency can also be provided.

The invention is explained in more detail below with reference to the accompanying schematic drawings using an exemplary embodiment.

Show in these:

1 cross-sectional representation of an embodiment of an electric motor unit with a stator unit of a rotor unit;

Fig. 2 detail of the cross-sectional view of the embodiment of the electric motor unit according to Fig. 1; and

Fig. 3 perspective view of a section of an electric motor unit.

1 and 2 show a cross-sectional representation of an embodiment of an electric motor unit 100 with a stator unit 1 and a rotor unit 2. In particular, the electric motor unit 100 is designed as a brushless electric motor. The rotor unit 2 is arranged centrally within the encompassing or surrounding stator unit 1.

The schematically illustrated rotor unit 2 preferably has several bonded (permanent) magnets, preferably four magnets with a total of eight magnetic poles.

For example, the magnets can be bound or embedded in a polymer, in the sense of a bound design.

Based on the number of (permanent) magnets, their individual size and the bonded design, the magnets can be protected from damage such as breakage or splintering.

Furthermore, the rotor unit can be produced in a simple, cost-effective manner and with only small tolerance deviations. In addition, the running properties of the resulting electric motor can also be improved.

The stator unit 1 is shown as an encompassing stator unit 1.

According to FIG. 1, the stator unit 1 has a comprehensive basic structure 10. The basic structure 10 can be formed in one piece or alternatively in several pieces.

In particular, the basic structure 10 of the stator unit 1 is shown in FIGS. 1 and 2 without an additional insulating layer. The geometry and the dimensions of the basic structure, in particular the stator teeth 12 and the slot sections 16, relate in particular to the electrically conductive components of the stator unit.

It is thus possible to form the stator unit 1 according to FIGS. 1 and 2 with an additional insulating layer.

In particular, the basic structure 10 of the stator unit 1 is provided with a hexagonal (basic) shape and geometry. The width of the stator unit 1, from one of the long sides to the opposite long side, can preferably be 33.8 mm. Furthermore, according to FIGS. 1 and 2, a total of six stator teeth 12 are provided, which are distributed equidistantly, each centrally along one of the long sides of the hexagonal basic structure 10, and extend in the central direction.

Slot sections 16 are formed between the stator teeth 12 arranged next to one another.

The slot sections particularly preferably have a width of between 2.5 and 3.0 mm, in particular 3.0 mm.

Accordingly, the electric motor unit has a specific ratio of six slot sections of the stator unit 1 to eight magnetic poles of the rotor unit 2.

Preferably, a cogging torque and noise development during operation of the electric motor unit, in particular for a sunroof unit, can be optimized or reduced.

A tooth head 30 can be formed at the central ends of the stator teeth 12. The stator teeth 12 and the tooth heads 30 therefore extend into an interior region 14 of the basic structure 10.

Furthermore, a longitudinal axis X is formed by each individual stator tooth 12. The stator teeth 12 can preferably be designed symmetrically to the respective longitudinal axis X.

Furthermore, the stator teeth 12 preferably each have a toothed web 36 with a width or a diameter of 2.5 mm.

The toothed webs 36 preferably allow optimal forwarding and guidance of the magnetic flux lines.

The tooth heads 30 have a circular section-shaped head surface 32 which is directed opposite to the rotor unit 2. Opposite the head surface 32, the tooth heads 30 or stator teeth 12 are formed with a bottom surface 34. Furthermore, a stator winding or coil winding or magnetic coil 20 is formed along the stator teeth 12, in particular formed opposite the bottom surface 34 along the toothed web 36.

The stator windings 12 are preferably designed symmetrically, in particular rotationally symmetrically, to the respective longitudinal axis X of the corresponding stator tooth 12. The stator windings 20 therefore each surround the corresponding stator tooth 12, in particular the respective toothed web 36.

Furthermore, a bottom surface 34 of the stator teeth forms an obtuse angle o with respect to the associated longitudinal axis X.

Preferably, the obtuse angle o can have a value of 127°.

Furthermore, the stator windings 20 each have a peripheral surface 24. The circumferential surface 24 forms an acute angle β with the associated longitudinal axis X, preferably an angle β of 30°.

Based on such a specific geometry of the stator teeth 12, including the intermediate slot sections 16, and/or the stator windings 20, in particular improved running/operating properties of the resulting electric motor unit can be provided.

Furthermore, it is provided that the mutually opposite circumferential surfaces 24 of the stator windings 20 arranged next to one another are designed or arranged parallel to one another. The respective slot section 16 is therefore further formed between the stator windings or coil windings or magnetic coils 20 arranged next to one another, as well as between the stator teeth 12.

3 shows a perspective view of a section of an electric motor unit 100.

In particular, a longitudinal end of a stator unit 1 is shown for an embodiment of the electric motor unit 100.

A head holder 50 is arranged at the longitudinal end of the stator unit 1. The head receptacle 50 essentially has the hexagonal (external) shape of the basic structure 10 of the stator unit 1.

A plurality of holding webs 52 and holding teeth 54 are formed along the head receptacle 50, in particular alternately formed.

3, the retaining teeth 54 are formed along the corners of the hexagonal basic shape of the head holder 50.

Furthermore, the holding webs 52 and the holding teeth 54 are designed to be spaced apart from one another in such a way that at least one cable 40 of the electric motor unit 100 can be passed through.

Accordingly, the at least one cable 40 can be guided or arranged on an outside of the holding teeth 54 and each along an inside of the holding webs 52.

In this way, the at least one cable 40 of the electric motor unit 100 can be secured and/or at least partially clamped, in particular by means of the retaining teeth 54.

Furthermore, the guidance along the inside of the holding webs 52 allows a space-saving and secure arrangement of the at least one cable 40.

In summary, the present invention can be used to provide an electric motor unit 100 which, using a stator and rotor unit according to the invention, in particular an embodiment with six slot sections 16 and eight magnetic poles, ensures improved running properties, an improved service life and a reduction in the running noise that occurs.

Furthermore, based on the specific geometry of the stator teeth 12, preferably in combination with a specific design of the coil/stator windings 20 and/or the bonded design of the (permanent) magnets in the rotor unit 2, an improved overall flux density and an optimized or reduced Cogging torque with constant or uniform sinusoidal characteristics can be achieved. Because the number of individual windings of the stator windings or magnetic coils 20 can be reduced, the manufacturing costs as well as the size and weight of the stator unit 1 can also be reduced in an advantageous manner.

Furthermore, the necessary installation space for the resulting (brushless) electric motor unit 100 can be advantageously reduced, in particular due to the hexagonal (basic) shape of the basic structure 10.

Reference symbol list

1 stator unit

2 rotor unit

10 basic structure

12 stator tooth

14 Interior

16 slot section

20 stator winding

24 peripheral area

30 tooth head

32 head area

34 floor area

36 tooth bar

40 cables

50 head shot

52 retaining bars

54 retaining teeth

100 electric motor unit o obtuse angle ß acute angle

X central axis

Claims

Claims Electric motor unit (100), in particular brushless electric motor unit, for a sunroof unit with a stator unit (1) and a rotor unit (2), the stator unit (1) having a surrounding basic structure (10) and a plurality of stator teeth (12) for receiving a plurality is formed by stator windings (20), so that six slot sections (16) are formed between the stator teeth (12), and wherein the rotor unit (2) is formed with eight magnetic poles. Electric motor unit (100) according to claim 1, characterized in that the rotor unit (2) has a plurality of magnets to form the magnetic poles, in particular four permanent magnets, the magnets preferably being designed as bonded magnets. Electric motor unit (100) according to one of the preceding claims, characterized in that each of the stator teeth (12) has a central axis (X) relative to which the respective stator winding (20) is designed symmetrically. Electric motor unit according to one of the preceding claims, characterized in that the individual stator teeth (20) each have at least one toothed web (36), at least one head surface (32) and a bottom surface (34). Electric motor unit (100) according to claim 4, characterized in that the respective bottom surface (34) of the individual stator teeth has an obtuse angle (o), preferably an angle between 90° and 160°, between 110° and 150° or between 120° and 140°, in particular 127°, relative to the central axis (X) of the respective stator tooth (12), and/or an edge guide (36) between the respective bottom surface with the respective head surface, preferably a radius between 0.05 and 1 .0mm, between 0.1 to 0.5 mm, between 0.15 and 0.3 mm or 0.2 mm. Electric motor unit (100) according to one of the preceding claims, characterized in that a peripheral surface (24) of the individual coil windings (20) has an acute angle (ß), preferably an angle between 5° and 70°, between 10° and 45° or between 20° and 40°, in particular 30°, relative to the central axis (X) of the corresponding stator tooth (12). Electric motor unit (100) according to one of the preceding claims, characterized in that the minimum width of the slot sections (16) is between 1 mm and 10 mm, between 2 mm and 5 mm or between 2.5 mm and 3 mm , in particular 3 mm. Electric motor unit (100) according to one of the preceding claims, characterized in that each of the toothed webs (36) has a tooth width or a tooth diameter between 0.5 mm and 10 mm, preferably between 1 mm and 5 mm, between 1. 5 mm and 3.5 mm or between 1.8 mm and 2.5 mm, in particular 2.5 mm. Electric motor unit (100) according to one of the preceding claims, characterized in that the basic structure (10) of the stator unit (1) has a hexagonal shape, in particular a hexagonal outer shape. Electric motor unit (100) according to one of the preceding claims, characterized in that the stator unit (1), in particular the basic structure (10) of the stator unit (1), has an external width of 33.8 mm. Electric motor unit (100) according to one of the preceding claims, characterized in that opposing peripheral surfaces (24) of adjacent stator windings (20), in particular cross-sectional edges of the Circumferential surfaces (24) of the stator windings (20) arranged next to one another are formed parallel to one another. Electric motor unit (100) according to one of the preceding claims, characterized in that a head holder (50) is arranged on a longitudinal end of the stator unit (1) with a plurality of holding webs (52) and a plurality of holding teeth (54) , wherein at least one cable (40) of the electric motor unit (100), in particular for electrically connecting the stator windings (20), is guided along an inner side of the holding webs (52) and each on an outside of the holding teeth (54). Sunroof unit for a vehicle, in particular a motor vehicle, with an electric motor unit (100) according to one of the preceding claims.