DE102019120340A1 - Stator and framework device for such a stator - Google Patents

Abstract

The invention relates to a stator 1, 1a, 1b, 1c, 1d, 1e for an electric motor with a plurality of annularly arranged stator cores 3, each stator core having a yoke section 4, a tooth section 5 and a foot section 6. In order to increase the rigidity of the stator, a bar 7, 7a, 7b is arranged between two adjacent stator cores 3, which at least in sections with the foot sections 6 of these adjacent stator cores 3 with a bracing in operative engagement, in particular in terms of material, shape and / or frictional connection. The invention also relates to a framework device for such a stator.

Description

The invention relates to a stator of an electric motor, in particular for a motor vehicle steering system, and to a framework device for such a stator.

An electric motor, but also a generator, are formed by a stator, the non-moving structural component, and a rotor, the moving or rotating component. Here, a stator is formed by a multiplicity of concentrically arranged stator modules, with adjacent stator modules, in particular their stator cores, having gaps between their stator teeth. A stator module is formed, inter alia, by its stator core and by a coil winding arranged around the stator core, in particular its stator tooth.

The closing of the slot gaps between two adjacent stator teeth is known in the prior art, among other things in order to reduce the whistling noises caused by the rotation. The slot gaps are, as in DE102004025105A1 described, closed by means of an insulating coating.

However, the result achieved is not satisfactory. It is also important to protect the stator teeth as well as possible from the tangential forces that occur in the stator due to the magnetic forces.

It is therefore the object of the present invention to improve the acoustic damping of a stator and to increase the rigidity of a stator.

The present invention specifies a stator according to claim 1 for this purpose. Advantageous developments are mentioned in the subclaims. In detail, it is a stator for an electric motor with a plurality of annularly arranged stator cores, each stator core having a yoke section, a tooth section and a foot section. A bar is arranged in each case between two adjacent stator cores and is at least partially in operative engagement with the foot portions of these adjacent stator cores with a bracing, in particular in a material, form and / or force fit.

As a result of the bracing, a force is applied to the stator cores in the circumferential direction, so that the entire stator, which is formed from the multiplicity of stator cores, is under internal compressive residual stress. This can dampen vibrations and achieve a higher overall strength, especially at high speeds.

The stator core includes the yoke portion, the tooth portion protruding outward from the yoke portion toward a first end facing away from the axis of rotation, and a foot portion at a second end facing toward the axis of rotation.

The bar can be pushed completely into the stator core along the axis of rotation, that is, it can extend from one end face of the stator to the opposite one. Furthermore, the bar can extend up to half of the stator core or take 1/3 or 1/4 of the length of the stator core, in other words, the bar can also be shortened, which saves material or can be arranged along the entire stator core depth between the foot sections.

The component or bar reduces the movement of the stator teeth due to the electromagnetic forces acting on the stator teeth. Essentially, the freedom of movement of the stator teeth is restricted by the strips and the aerodynamic profile properties of the inner circumference of the stator are improved. Here, the strips can be aligned with the inner circumference, which is in particular partially formed by the underside or surface of a foot section, and / or have an arcuate cross section towards the axis of rotation of the stator. Likewise, the strips can in particular be designed to be longitudinally and / or transversely symmetrical. This leads to a reduction in engine vibrations and thus to an improvement in the noise / vibration / load capacity (= NVH) behavior of the engine.

The bar is preferably made of a non-magnetic material, in particular made of plastic or wood or ceramic. As a result, the magnetic field lines that are generated by the coils of the stator modules are not deflected or influenced. There are also some materials with better damping and temperature properties, such as thermosets.

Here, the bar and one of the foot sections that are in operative engagement with the bar can be shaped in the area of a contact section of the foot section in such a way that a tongue and groove connection is formed. The strips are preferably pressed into the gap between the stator teeth and form a stable connection to the foot sections of the adjacent stator cores.

Advantageously, at least one of the strips has a cross-sectional profile with a convex and / or a concave contact surface, in particular a star-shaped profile or a double-T profile, which is in operative engagement with the foot section, in particular its contact section. Here it is easy to manufacture forms that enable a stable and firm connection.

In a further embodiment, the bar has in each case an end stop which is in contact with the foot sections of the adjacent stator cores and prevents the bar from being pushed into the space between the foot sections. This has the advantage that the bar can be inserted up to a predetermined point and a simultaneous check of the inserted length becomes superfluous. This simplifies the manufacturing process and allows the stators to be built in a consistent manner.

In order to speed up the assembly of the stator, the end stops of the strips can form an annular structure or be connected together. This means that all strips of a stator can be used at the same time. The ring-shaped structure with the strips forms a so-called frame or cage device, as will be described in detail later.

The bar is preferably designed with an insulation wall which extends between the tooth sections of two adjacent stator cores. The strip and the insulation wall are formed in one piece or in one piece. This has the advantage of separating the coil windings of two adjacent stator modules from one another or of electrically isolating them.

It has proven to be advantageous for the structural consistency of a stator if the bar is formed on an insulating coil body which is arranged around the tooth section of each stator core. The bar and the insulating coil body are preferably formed in one piece or in one piece, for example by means of a common plastic injection molding. This has the advantage that the bar cannot be inserted into the stator separately, but rather simultaneously with the coil body, in particular between the contact sections of the foot section. This also reduces the number of individual parts of the stator. Preferably, a bar is always formed on a coil body.

The invention also relates to a framework device for a stator according to the invention. The framework device has an annular base with a large number of strips, the strips being shaped, arranged and / or aligned in such a way that each strip can be inserted between two adjacent stator cores of the stator and thereby in operative engagement with the foot sections of these adjacent stator cores, in particular in a form fit and / or frictional connection, can be brought.

Advantageously, predetermined breaking points are formed between the annular base and the strips in order to break away the base after the strips have been inserted into the stator. This temporary scaffolding device bypasses the need to insert the strips individually.

The strips are preferably arranged perpendicular to the base, in particular to the plane of an annular base. Alternatively, the strips could be connected to a guide rod and arranged parallel to it. The connection between the bar and the guide rod forms an obtuse angle between the two components. This allows a better power transmission from the rod to the bars and thus a finer and more precise pressing of the bars into the stator.

The figures described below relate to preferred exemplary embodiments of the stator according to the invention, whereby these figures do not serve as a restriction, but essentially serve to illustrate the invention. Elements from different figures but with the same reference symbols are identical; therefore the description of an element from one figure is also valid for elements with the same name or with the same number from other figures.

Figure list

• 1 a motor vehicle steering system with an electric motor, gearbox and axle;
• 2 a plan view of a stator according to a first embodiment;
• 2A a perspective view of the stator according to FIG 2 ;
• 3 a plan view of a stator according to a second embodiment;
• 3A a perspective view from below of part of a stator according to FIG 3 ;
• 3B a perspective view of an insulating bobbin from a stator according to FIG 3 ;
• 4th a plan view of a stator according to a third embodiment;
• 4A a perspective view of part of a stator according to FIG 4th ;
• 5 a plan view of a stator according to a fourth embodiment;
• 5A a perspective view of part of a stator according to FIG 5 ;
• 5B a view of a bar for increasing the rigidity of a stator according to the invention, in particular according to 5 ;
• 6 a perspective view from below of a stator according to a fifth embodiment;
• 6A a view of a framework device according to the invention for a stator according to the invention, in particular according to 6 ;
• 7th a perspective view of a stator according to a sixth embodiment; and
• 7A a perspective view of part of a stator according to FIG 7th .

1 shows a motor vehicle steering system 100 with an electric motor 110 , a transmission 120 and an axle or shaft 130 . The stator according to the invention (not visible) is in the electric motor 110 built in, whereby an exemplary application of the stator is shown. The gear 120 serves to transmit and deflect the rotational movement from the axis of the electric motor 110 on the axis 130 . The transmission can 120 also have a translation, for example by the rotational speed of the axis 130 to reduce and increase its torque.

2 shows a top view of a stator 1 according to a first embodiment. The stator 1 is ring-shaped, in particular a hollow cylinder, and is made up of a large number of stator modules 2 educated. All stator modules 2 are of the same size and each form a section or segment of the annular stator 1 . The stator modules 2 are arranged next to each other and concentrically around an axis of rotation (marked with X). The stator modules 2 each have a stator core 3 , a wire 8th and an insulating bobbin 12th , preferably with a ledge 7th , on. The stator core 3 is by an externally arranged yoke section 4th , an internally arranged foot section 6 and a tooth section connecting the two previous sections 5 educated. The yoke section 4th describes or lies on the outer circumference of the stator 1 . The opposite ends of the yoke section 4th form a convex engagement portion 10 and an engaging concave portion 11 which are each positively connected to the correspondingly oppositely designed engagement sections of the yoke sections of the adjacent stator cores. The foot section 6 describes or lies on the inner circumference of the stator 1 . The opposite ends of the yoke section 4th each form a contact section 9 , the one with a correspondingly oppositely designed bar 7th is positively connected. The bar 7th is positive and / or non-positive between two contact sections 9 two adjacent stator cores 3 arranged. The tooth section 5 forms a connecting web between the yoke section 4th and foot section 6 . Around the tooth section 5 is a wire 8th arranged, which has an electrically conductive winding or coil around the tooth section 5 forms. The wire 8th can be one or more parts. So that the wire 8th opposite the stator core 3 Is isolated and in particular has a stable arrangement or seat, is between the wire 8th and the stator core 3 , especially the tooth section 5 , an insulating bobbin 12th arranged. The wire 8th is thus around the bobbin 12th wrapped.

2A shows a perspective view of the stator 1 according to 2 , with a few segments, especially stator modules 2 , the stator 1 have been omitted to illustrate the components. Here is the surface of the engaging concave portion 11 completely visible, which has a groove formed parallel to the axis of rotation. This groove extends from the top of the stator core 3 down to its bottom. The convex engagement portion 10 has a ridge that fits into the groove. Similar to the engaging concave portion 11 is the area of the contact section 9 shaped, in which a groove arranged parallel to the axis of rotation is also formed. The groove of the contact section 9 comes with one side of the bar 7th extending from the top of the stator core 3 extends to its underside, in operative engagement. Furthermore, the shape of the insulating bobbin 12th shown in more detail. The bobbin 12th has two cup-shaped components, each between the walls of the yoke section 4th , the tooth section 5 and the foot section 6 are arranged and through which the wire 8th runs several times due to the winding. A rectangular wall that forms the cup-shaped component of the bobbin 12th covers is between two adjacent stator modules 2 retracted and extends radially and flat to the surface of the convex or concave engagement portion 10 , 11 .

3 shows a top view of a stator 1a according to a second embodiment, which extends from the stator 1 especially with regard to the groin 7a differs. Here are the bobbins 12a and the bar 7a For example, they have been produced by a joint plastic injection molding process and are thus connected to one another in one piece. This has the advantage that the bar 7a not separately, but at the same time as the bobbin 12a in the stator 1a , in particular between the contact sections of the foot section 6 can be used.

3A shows a perspective view from below of part of a stator 1a according to 3 . In this case, the bar extends 7a as previously shown in the other figures, not completely over the entire gap between the contact portions 9 two adjacent contact cores 3 . Instead, the groin extends 7a only from the bottom of the foot section 6 until about the middle of the gap.

3B shows a perspective view of an insulating bobbin 12a from a stator 1a according to 3 on which a ledge 7a is trained. The bar 7a has a predetermined position and orientation around it without deformation between the foot portions of a stator core 3 to arrange.

4th shows a top view of a stator 1b according to a third embodiment, which extends from the stator 1 especially with regard to the groin 7b differs. The bar 7b instead of a star-shaped cross-section, has a double-T-beam cross-section. Alternatively formulated: the bar 7b can have concave side surfaces instead of convex side surfaces. The contact section 9a of the foot sections 6 is opposite to the side surface of the bar 7b shaped.

4A shows a perspective view of part of a stator 1b according to 4th . The bar 7b extends along the entire gap between the contact sections 9a . Also is the bar 7b as a single component, but can also alternatively with the coil body 12th be made in one piece.

5 shows a top view of a stator 1c according to a fourth embodiment, which extends from the stator 1 in particular with regard to the bar 7c differs. In addition to the component arranged between the contact sections of the foot sections, the bar 7c also has an insulation wall 13 on. The isolation wall 13 essentially corresponds to the in 2A described rectangular wall between the adjacent stator modules 2 . In this case the isolation wall is 13 integrally connected to the bar 7c.

5A shows a perspective view of part of a stator 1c according to 5 . Both the bar 7c and the insulation wall 13 extend from the top of the module core to the bottom. Additionally or alternatively, the bar 7c and its insulation wall 13 with the bobbin 12b be connected in one piece.

5B shows a view of a bar 7c for increasing the rigidity of a stator according to the invention, in particular according to FIG 5 . In addition to the already described bar 7c and the insulation wall 13 is an end stop at the end of the bar 7c 14th formed in the form of a rectangular area. The end stop 14th ensures that the bar can only be inserted or arranged up to a certain point in the space between the contact sections of adjacent foot sections.

6 shows a perspective view from below of a stator 1d according to a fifth embodiment. The ten strips are between the foot sections of the stator cores 3 inserted and connected with a decagonal ring on one side. This framework or cage device enables the simultaneous insertion of all strips between the stator cores and thus shortens the manufacturing time of a stator 1d .

6A shows a view of a framework device according to the invention for a stator according to the invention, in particular according to FIG 6 . The bars 7b have like in the 4th a double T-beam cross-section. One end of the bar 7b is with one compared to the length of the bar 7b short web or extension 17th on a decagonal alignment ring 16 attached and aligned. The extension is preferably equipped with a predetermined breaking point around the ring 16 after inserting the strips 7b break away and remove. The ring 16 is formed by ten straight, equally long and rectangular bars that are connected to a ring at their ends. At the corners of the ring 16 is one bar each 7b with the appendix 17th attached.

7th and 7A show a perspective view of a stator 1e and on part of this stator 1e according to a sixth embodiment. Compared to the stator 6 the scaffolding device differs 15a . This device 15a can just like the first scaffolding device 15th all bars at the same time between the module cores 3 deploy. However, the device is 15a as permanent insertion including its ring-shaped end stop 14a intended. Compared to the alignment ring 16 the first scaffolding device 15th remains the end stop 14a after inserting the strips on them and will not be broken off. The end stop 14a has an annular inner circumference and a decagonal outer circumference, whereby all foot portions of the stator cores are covered. The inner circumference is shaped like a ring so as not to obstruct an insertable rotor.

List of reference symbols

1

Stator, first embodiment

1a

Stator, second embodiment

1b

Stator, third embodiment

1c

Stator, fourth embodiment

1d

Stator, fifth embodiment

1e

Stator, sixth embodiment

2

Stator module

3

Stator core

4th

Yoke section

5

Tooth section

6th

Foot section

7th

strip

7a

Bar of the second embodiment

7b

Bar of the third embodiment

8th

wire

9

Contact section

9a

Contact portion of the third embodiment

10

convex engagement portion

11

engaging concave portion

12

insulating bobbin

12a

insulating bobbin of the second embodiment

12b

insulating bobbin of the fourth embodiment

13

Isolation wall

14th

End stop

14a

End stop

15th

Scaffolding device

15a

Scaffolding device

16

Alignment ring

17th

Appendix

100

Motor vehicle steering

110

Electric motor

120

transmission

130

axis

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102004025105 A1 [0003]

Claims (10)

Stator (1, 1a, 1b, 1c, 1d, 1e) for an electric motor, with a plurality of annularly arranged stator cores (3), each stator core (3) having a yoke section (4), a tooth section (5) and a foot section ( 6), characterized in that a bar (7, 7a, 7b) is arranged between two adjacent stator cores (3), which at least in sections with the foot sections (6) of these adjacent stator cores (3) with a bracing in operative engagement, in particular in material, form and / or frictional connection. Stator after Claim 1 , characterized in that the bar (7, 7a, 7b) is made of a non-magnetic material. Stator after Claim 1 or 2 , characterized in that the bar (7, 7a, 7b) and one of the foot sections (6) which are in operative engagement with the bar in the area of a contact section (9) of the foot section (6) are shaped in such a way that a tongue and groove connection is formed. Stator according to one of the Claims 1 to 3 , characterized in that the bar (7, 7a, 7b) has a cross-sectional profile with a convex and / or a concave contact surface which is in operative engagement with the contact section (9) Stator according to one of the Claims 1 to 4th , characterized in that the bar (7, 7a, 7b) has an end stop (14, 14a) which is in contact with the foot sections (6) of the adjacent stator cores (3) and the bar is pushed into the space between the foot sections (6) prevented. Stator after Claim 5 , characterized in that the end stops (14a) of the strips (7, 7a, 7b) form an annular structure or are connected together. Stator according to one of the Claims 1 to 6 , characterized in that the bar (7, 7a, 7b) is formed with an insulation wall (13) which extends between the tooth sections (5) of two adjacent stator cores (3). Stator according to one of the Claims 1 to 7th , characterized in that the bar (7, 7a, 7b) is formed on an insulating bobbin (12) which is arranged around the tooth section (5) of each stator core (3). Framework device for a stator according to one of the Claims 1 to 8th , characterized in that the framework device has an annular base with a plurality of strips (7, 7a, 7b), the strips being shaped, arranged and / or aligned in such a way that each strip is between two adjacent stator cores (3) of the stator ( 1) can be used and can be brought into operative engagement with the foot sections (6) of these adjacent stator cores (3), in particular in a form fit and / or force fit. Scaffolding device according to Claim 9 , characterized in that predetermined breaking points are formed between the ring-shaped base and the strips (7, 7a, 7b) so that after the strips (7, 7a, 7b) have been inserted into the stator (1, 1a, 1b, 1c, 1d, 1e) to break away the base.

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