CN111817470A

CN111817470A - Stator for three-phase electric motor

Info

Publication number: CN111817470A
Application number: CN202010280528.4A
Authority: CN
Inventors: 米蒂亚·耶里奇; 艾尔贾兹·兹贡
Original assignee: Mahle International GmbH
Current assignee: Mahle International GmbH
Priority date: 2019-04-10
Filing date: 2020-04-10
Publication date: 2020-10-23
Anticipated expiration: 2040-04-10
Also published as: DE102019205123A1; CN111817470B

Abstract

The present invention relates to a stator for a three-phase electric motor. The stator has a hollow-cylindrical coil carrier and a plurality of stator coils, which are oriented parallel to the longitudinal center axis of the coil carrier and are arranged distributed in the coil carrier around the longitudinal center axis. Furthermore, at least one end contact unit is formed at an axial switching end of the coil carrier, said at least one end contact unit comprising contact ends of a plurality of, in particular six, stator coils of the three-phase stator. The individual contact ends of the stator coils in the end contact units are electrically contacted in a corresponding manner by means of an interconnection device. According to the invention, the interconnection device has three elongate, shaped contact strips which are oriented perpendicularly to the longitudinal mid-axis and overlap axially spaced apart from one another. In this case, the individual contact strips are in particular in pairs and correspondingly in electrical contact with the contact ends of the stator coils in the end contact units.

Description

Stator for three-phase electric motor

Technical Field

The present invention relates to a stator for a three-phase electric motor according to the preamble of claim 1.

Background

Electric motors are known from the prior art. The internal electric motor has a stator and a rotor arranged coaxially in the stator, which is connected in a rotationally fixed manner to the drive shaft. The stator has a plurality of winding coils which are arranged in an electrical insulator so as to be distributed around the rotor in the circumferential direction. The winding coils are interconnected in circuit with each other, whereby the winding coils are in electrical contact with each other (e.g., welded) at a wire end at one axial end of the stator thereof. The three-phase current of the external current source may then be applied to the winding coil, whereby the phase contacts of the current source must be in electrical contact (e.g. soldered) with the interconnected wire ends of the winding coil. If three-phase currents are applied to the wire ends of the respective winding coils, a rotating magnetic field is generated in the stator and the rotor is rotated.

The individual wire ends of the winding coil and the wire ends that are in contact with one another and the phase contacts of the external current source must be in electrical contact with one another, which is often associated with high expenditure.

Disclosure of Invention

The object of the present invention is therefore to propose an improved or at least alternative embodiment for a stator of the generic type, in which the described disadvantages are overcome.

According to the invention, this object is achieved by the subject matter of the independent claims. Advantageous embodiments are the subject of the dependent claims.

A stator for a three-phase electric motor has a hollow cylindrical coil carrier and a plurality of stator coils wound respectively on winding projections of the coil carrier. The stator coils are oriented parallel to the longitudinal center axis of the coil carrier and are arranged distributed in the coil carrier around the longitudinal center axis. At least one end contact unit is formed at an axial switching end of the coil carrier, said at least one end contact unit comprising the contact ends of a plurality of, in particular six, stator coils of the three-phase stator. The respective contact ends of the stator coils are then electrically contacted in a corresponding manner in the end contact units by means of the interconnection means. According to the invention, the interconnection device has three elongated contact strips which are oriented at the axial switching ends perpendicularly to the longitudinal center axis and overlap axially at a distance from one another. The individual contact strips are in particular in pairs and correspondingly in electrical contact with each other in the end contact units with the contact ends of the stator coils.

The contact ends of the respective stator coils are combined into an end contact unit. In this case, the stator can have both an end contact unit and a plurality of end contact units and accordingly both an interconnection device and a plurality of interconnection devices. The number of interconnection means then corresponds to the number of end contact units in the stator. The contact ends in the respective end contact units are then in particular in pairs and correspondingly in electrical contact with one another via the three contact strips of the respective interconnection device. In the following, for the sake of simplicity, reference will be made to the description of a stator with an end contact unit and with an interconnection device. If the stator has further end contact units and further interconnection means, they can be constructed identically to one another. The contact end of the stator coil is formed by the wire end of the stator coil wound onto the winding overhang. The contact strips of the interconnection device and the respective contact ends of the individual stator coils, i.e. the individual line ends, are in particular in pairs and in phase correspondence in electrical contact with one another, so that the contact ends of the stator coils can be connected to three phases of an external current source via the contact strips (U, V, W).

The contact strips are made of an electrically conductive material, so that the contact ends of the stator coils, which are fixed to the respective contact strips, are electrically contacted to each other via the contact strips. The contact ends of the stator coils are advantageously fixed in an electrically conductive manner at the contact strips and are welded or soldered to them, for example. The contact strips are elongate and preferably flat and bridge the distance between the contact ends of the stator coils to be contacted in the end contact units. The electrical contacting of the contacting ends of the stator coils is thereby significantly simplified. Furthermore, the contact strips overlap one another and are thus arranged on the coil carrier in a space-saving manner. The individual contact strips are spaced apart and are thus arranged electrically insulated from one another and do not have direct contact with one another.

In a development of the stator according to the invention, each contact strip advantageously has a central overlapping section, to the two sides of which a receiving section of the contact end of the respective stator coil is connected in each case. The contact strips axially adjacent to the longitudinal center axis in the overlapping section overlap one another and fix the contact ends of the stator coils at the receiving section. The respective phase contact strips are electrically conductive and the contact ends of the stator coils are advantageously fixed to the respective contact strips in an electrically conductive manner. The contact ends of the stator coils are in this way brought into electrical contact with one another, in particular in pairs and correspondingly, via the contact strips. In addition, the one contact strip and the other contact strip are arranged at an angle to one another in a plane radial to the longitudinal center axis in the overlapping section in order to be able to accommodate contact ends of adjacent stator coils distributed around the longitudinal center axis.

The receiving sections of the individual contact strips can advantageously lie in a common receiving plane perpendicular to the longitudinal center axis. The contact ends of the stator coils are thus of identical design and are in electrically conductive contact with the contacts axially in the same receiving plane, whereby the outlay in the production of the stator is significantly reduced. For this purpose, a step section can be provided between at least one of the receiving sections and the overlapping section of the respective contact strip, which step section axially offsets the receiving section relative to the overlapping section. The individual contact strips can be produced and shaped in a stamping process.

Preferably, the upper one of the axially spaced contact strips has downwardly offset receiving sections on both sides, and the lower one of the axially spaced contact strips has upwardly offset receiving sections on both sides. The central one of the axially spaced contact strips then has no step sections on both sides. The expressions "lower", "middle" and "upper" relate here to the axial distance of the overlapping sections of the respective contact strips from the coil carrier, which increases from the "lower" to the "upper" part. Suitably, the receiving sections of the lower and upper contact strips are axially offset by the distance of the lower and upper contact strips, respectively, from the middle contact strip, so that the axial distance is compensated. The central contact strip and the receiving sections of the lower and upper contact strips then lie in a common receiving plane and the contact ends of the stator coils are brought into contact with the contact strips in a cost-effective and reliable manner.

The respective contact ends can be fixed in the receiving portion with a material fit, preferably by gas welding, at the respective contact strips. In order to also be able to fix the respective contact end in the receiving section over a large area, the receiving section of the respective contact strip can have at least one axially oriented coupling projection which projects from the respective contact strip. The respective axially aligned contact ends, i.e. the line ends, of the individual stator coils can be fixed in large-area abutment against the respective coupling projections. Advantageously, the respective contact end of the stator coil can thereby be brought into electrical contact with the respective contact reliably and with reduced effort.

In order to be able to correspondingly connect the phase contact strips to an external current source, axially oriented phase terminal pins can be integrally formed at the respective phase contact strips, facing away from the coil carrier. Alternatively, the individual phase connection pins can also be fixed to the contact strips by material fit, preferably by resistance welding. The respective contact strips can be made of copper, for example, in order to achieve a positive fixation of the phase contact end material in the receiving section by gas welding. For example, the individual integrally formed or also material-fittingly fixed phase connection pins can be coated with a nickel-tin layer in order to achieve a material-fittingly fixing of the phase connection pins by soldering at the phase connections of the external current source.

The stator coils can advantageously be interconnected in a first star circuit with three first phase terminals and in a second star circuit parallel to the first star circuit with three second phase terminals. Subsequently, each first phase terminal and each second phase terminal are formed by the contact end portions of the corresponding stator coils. The contact strips of the interconnection device and the contact ends of the respective stator coils are in electrical contact with one another in each case. Alternatively to a parallel star circuit, the stator coils can advantageously be interconnected in a delta circuit with three phase terminals. The respective phase terminals are formed by contact ends of the respective stator coils and are correspondingly electrically contacted to each other via contact strips.

In an advantageous development of the stator, the stator has an electrically insulating insulator which surrounds the interconnection device at least in some regions in a form-fitting manner and electrically insulates the contact ends, which are electrically contacted with one another via the interconnection device, from one another in each case. The insulating body at least partially surrounds the contact strips of the interconnection device in a form-fitting manner, so that the respective contact ends are correspondingly electrically insulated from one another. The contact strips are separated from each other at least axially with respect to the longitudinal center axis and at least in the respective overlapping sections by an insulator and are thereby correspondingly electrically insulated from each other. In particular, the insulator can axially space the individual phase terminals and fix them at an angle to one another. Suitably, the receiving section of the respective contact strip and the phase terminal pin at least partially protrude from the insulating body in order to interconnect the stator coils to each other by means of the interconnection means and to be connectable to an external current source.

The insulating body can be made of an electrically insulating plastic, for example, and can be extruded around the interconnection device in a plastic injection molding process. The insulating carrier body then surrounds the contact strips of the interconnection device in a form-fitting manner and is fixed thereto in a material-fitting manner in a non-releasable manner. The intermediate space between the contact strips is filled with an electrically insulating plastic material of the insulating body and the contact ends fixed to the contact strips are fixed to one another at an axial distance and are electrically insulated from one another.

In a development of the insulating body, the insulating body has an annular support ring which radially surrounds the longitudinal center axis and is fastened at axial switch ends to the coil support at a distance in a plane radial to the longitudinal center axis. At the carrier ring, at least one insulating cover can be integrally formed, which at least partially surrounds and electrically insulates outwardly at least some contact ends of the stator coils in a form-fitting manner at the axial switching ends. In particular, the contact ends of the stator coils forming the star point of the star circuit can thereby be electrically insulated. The insulating carrier then surrounds the contact strips of the interconnection device and the contact ends of the stator coils, which are in electrical contact with one another, which are formed by the wire ends of the respective stator coils. The contact end differs from the contact end only in its function and is provided for interconnecting the stator coils to one another. The insulating cover can extend radially outward or radially inward at the carrier ring. Since the carrier ring is fixed at the coil carrier at a distance from and fixed against displacement relative to the coil carrier, the contact ends in the interconnection device received by the insulator and in the insulating cover are better protected against mechanical damage.

In order to fix the carrier ring at a distance from the coil carrier, the holding arms can be integrally formed or fixed to the carrier ring with a positive and/or material fit. The holding arms each have a radial section which extends radially outward and is connected to the carrier ring, and an axial section which extends axially toward the coil carrier and is connected to the radial section. The holding arm is then fixed to the coil carrier by means of the respective axial section in a form-fitting and/or material-fitting manner. The carrier ring is therefore axially supported on the coil carrier and the contact strips of the interconnection device, which are accommodated by the insulating body, and the contact ends of the stator coils are fixed in a rotationally fixed manner relative to the coil carrier. The electrical contacting of the stator with an external current source and the electrical contacting of the contacting ends of the stator coils with the interconnection means can thereby be significantly simplified. Preferably, a plurality of holding arms are provided which are distributed uniformly in the circumferential direction at the carrier ring in order to uniformly support the carrier ring at the coil carrier. Alternatively or additionally, a plurality of holding arms can be provided at the carrier ring in the region of the phase contact.

Advantageously, a first positive-fit contour is formed at the axial section and a second positive-fit contour is formed at the coil carrier, the first and second positive-fit contours engaging axially and positively with one another. Here, the first or second positive contour can be an integrally formed projection and the second or first positive contour can be a recess or a cutout complementary to the projection. In addition, the individual projections and the corresponding recesses or cutouts can also be secured to one another in a material-locking manner, so that an undesired detachment of the insulator from the coil carrier is prevented.

In an advantageous development of the stator according to the invention, the stator has a housing with a housing wall surrounding the longitudinal center axis and a housing base with an axially closed housing wall. The coil carrier is then arranged coaxially in the housing and is fixed in a rotationally fixed manner by means of a fixing device. The fastening device has a first fastening contour and a second fastening contour. The first fixing contour here comprises a plurality of fixing projections which project radially inward from the housing wall and are arranged distributed in the circumferential direction only in the region of the housing base. The second fastening contour comprises a plurality of fastening recesses oriented radially inward, which are shaped at the coil carrier body towards the housing wall. The fixing projection is complementarily shaped with respect to the fixing recess and radially engages with said fixing recess.

The fastening projections are arranged only in the region of the housing base and project axially from the housing base and radially from the housing base by a few millimeters to a few centimeters. The fixing projections can be integrally formed at the housing wall or at the housing bottom or both. Furthermore, the fastening projections are arranged distributed over the circumference of the housing base such that the coil carrier engages the housing over its entire circumference. Advantageously, the fastening recesses and the fastening projections are also distributed uniformly in the circumferential direction, so that the torque acting on the coil carrier is transmitted uniformly to the plurality of fastening projections engaging with the fastening recesses. Suitably, the housing bottom is arranged axially opposite the axial switch end of the coil carrier, so that a phase terminal pin of the interconnection device for connecting an external current source is accessible.

An inner circumferential gap can advantageously be formed between the respective fixing recess and the fixing projection which engages with the fixing recess accordingly. The circumferential gap can simplify the arrangement of the coil carrier in the housing and can compensate for manufacturing tolerances. Preferably, the surrounding gap has a width of 75 μm to 125 μm.

In an advantageous embodiment, the coil carrier has a plurality of individual segments which each carry a stator coil and which are arranged in the housing distributed in the circumferential direction around the longitudinal central axis. Each body section has an insulating carrier and a conductor core component which is at least partially surrounded by the insulating carrier. The insulating carrier has a surrounding plate with a winding protrusion protruding radially inward from the surrounding plate. The winding projections are integrally formed at the surrounding plate and the respective stator coils are wound at the winding projections. The body sections of the coil carrier are expediently of identical design, in order to reduce the effort required for producing the coil carrier.

The respective fixing recess can advantageously be formed by two half recesses at the contact points of adjacent body sections. The respective half-recesses are formed here in each case toward one another at the adjacent body sections. The number of fastening recesses in the coil carrier is then determined by the number of body sections of the coil carrier. The number of fastening projections in the housing then corresponds, as appropriate, to the number of body sections in the coil carrier. Advantageously, the recess halves can be shaped in the surrounding plate of the respective insulating carrier and extend axially groove-like over the entire height of the surrounding plate. Thus, radial semi-bulges in each conductor core part can be shaped, which axially extend over the entire height of the respective conductor core part. The half-projections of the conductor core part can then engage radially inwardly into the half-recesses of the surrounding plate and close the fixing recesses axially over the entire height of the respective conductor core part. The conductor core parts of adjacent body sections then bear against one another over the entire height in the contact region.

Furthermore, the half-elevations of the individual conductor core parts can be axially adjacent to the respective fixing elevations in the respective fixing recesses. Suitably then, the half-bulges of the conductor core part only partially close the half-recesses of the insulating carrier and the respective fixing recesses remain axially open on one or both sides. Each fixing recess then partially radially engages with the corresponding fixing projection and partially radially engages with the half projection of the corresponding conductor core member. In order to stabilize the coil carrier, the half-elevations of the individual conductor core parts of adjacent body sections can engage in a form-fitting manner in the circumferential direction over the entire height of the conductor core parts via the axial grooves and the complementary axial elevations. The adjacent body sections can be secured to one another in a material-fit manner, preferably by ultrasonic welding, at the semi-elevations of the respective conductor core parts and thus form a one-piece coil carrier.

In a development of the coil carrier, the respective insulating carrier can be made of plastic and injection-molded on the respective conductor core part in a plastic injection molding process. Suitably, the plastic is electrically insulating. Alternatively, the respective insulating carrier part can be formed in two parts and at least partially surround the respective conductor core part axially on both sides and in a form-fitting manner. The two-part insulating carrier can be produced, for example, from an electrically insulating plastic in a plastic injection molding method.

Advantageously, the coil carrier can have at least one cutout which is oriented radially outward and in which a contact end or a contact end of the respective stator coil is fixed in an at least partially form-fitting manner. In addition, the or each contact end can also be secured in the cutout in a material-locking manner. The cutout is oriented outward and extends axially at the coil carrier. In this way, the or each contact end of the stator coil can be axially oriented at the axial switching end of the coil carrier. In particular, the contact of the stator coil with the interconnection means can thereby be simplified.

Further important features and advantages of the invention emerge from the dependent claims, the figures and the associated description of the figures in accordance with the figures.

It is to be understood that the features mentioned above and those yet to be explained below can be used not only in the respectively given combination, but also in other combinations or alone without departing from the scope of the present invention.

Drawings

Preferred embodiments of the invention are illustrated in the figures and are set forth in detail in the following description, wherein like reference numerals refer to identical or similar or functionally identical components.

Are respectively schematically shown

Fig. 1 is a view of a stator according to the invention with a coil carrier and an insulator;

fig. 2 is a view of the coil carrier in the housing shown in fig. 1;

fig. 3 and 4 are sectional views of the coil carrier with the fixing device shown in fig. 2;

fig. 5 is an enlarged sectional view of a fixing device of the stator shown in fig. 1;

fig. 6 and 7 are views of the coil carrier of the stator shown in fig. 1;

fig. 8 and 9 are views of the insulated carrier of the coil carrier shown in fig. 6 and 7 or a portion thereof;

FIG. 10 is a view of an interconnect with a contact strip, the interconnect being partially surrounded by an insulator;

FIGS. 11 and 12 are views of the interconnect shown in FIG. 10 with contact strips;

FIGS. 13-15 are views of a contact strip of the interconnect shown in FIGS. 10-12;

FIGS. 16 and 17 are views of the insulator of the stator shown in FIG. 1 with the interconnection means surrounding;

FIG. 18 is a schematic illustration of a possible interconnection of stator coils in the stator shown in FIG. 1;

fig. 19 is a view of the stator shown in fig. 1 with stator coils interconnected according to fig. 18.

Detailed Description

Fig. 1 shows a view of a stator 1 according to the invention with a hollow-cylindrical coil carrier 2. The coil carrier 2 is composed of a plurality of body sections 4 which are arranged distributed around a longitudinal center axis 3 of the coil carrier 2, as explained in detail below with reference to fig. 6 to 9. Each body section 4 has an electrically insulating carrier 5 and an electrically conductive conductor core component 6, which is at least partially surrounded by the insulating carrier 5. The insulating carrier 5 has a surrounding plate 7 with winding projections 8 which project radially inwards from the surrounding plate 7. Stator coils 9 are wound on the respective winding overhang 8, which are oriented parallel to the longitudinal center axis 3 within the coil carrier 2 and are arranged distributed around it. Each coil protrusion 8 forms an integral part of each insulating carrier 5 and electrically insulates each wound stator coil 9 from the conductor core component 6. The individual coil projections 8 and the stator coils 9 wound thereon in each case together form stator teeth of the stator 1 which project radially inward. A total of twelve individual segments 4 of the coil carrier 2 are of identical design.

Six of the adjacently arranged stator coils 9 each have a contact end 11a of one of the three phases U, V, W at the axial switching end 10 of the coil carrier 2. The contact ends 11a are formed by the wire ends of the wound stator coil 9 and are electrically contacted to one another in a corresponding manner by means of an interconnection device 12. For this purpose, the interconnection means 12 has three flat and elongate shaped contact strips 13, as explained in more detail below with reference to fig. 10 to 15. The contact strips 13 are oriented at the axial switching end 10 perpendicularly to the longitudinal center axis 3 and overlap one another at an axial distance. Furthermore, at the contact strip 13, three phase connection pins 14 for the individual phases U, V, W are integrally formed or fixed in a material-fitting manner, to which phase connection pins an external current source can be connected. In this embodiment, the stator 1 has a separate end contact unit and a separate interconnection means 12.

Furthermore, the stator 1 has an electrically insulating insulator 15 which surrounds the interconnection device 12 in a partially form-fitting manner and electrically insulates the contact ends 11a of the stator coils 9, which are in electrical contact with one another via the interconnection device 12, from one another in a corresponding manner. The contact strips 13 and the phase connection pins 14 here project partially from the insulating body 15 in order to interconnect the stator coils 9 to one another by means of the interconnection means 12 and to be able to be connected to an external current source. The insulating body 15 has a carrier ring 16 radially surrounding the longitudinal center axis 3 and a plurality of retaining arms 17, as will be explained in more detail below with reference to fig. 16 and 17. The interconnection means 12 with the contact strip 13 is here received by a carrier ring 16. The first positive fit contour 18a is formed at the retaining arm 17 and the second positive fit contour 18b, by means of which the carrier ring 16 is fixed at the coil carrier 2 in a spaced-apart and positive fit, is formed at the coil carrier. Furthermore, the insulating body 15 has two insulating covers 19 which receive the contact ends 11b of the stator coils 9 in electrical contact with one another in a form-fitting manner and are electrically insulated to the outside.

Fig. 2 shows a view of the coil carrier 2 in the housing 20 of the stator 2. The pot-shaped housing 20 has a housing wall 21 surrounding the longitudinal center axis 3 and a housing bottom 22 axially closing the housing wall 21. The coil carrier 2 is arranged coaxially in the housing 20 and is fixed in a rotationally fixed manner. The housing base 22 is arranged axially opposite the axial switch end 10 of the coil carrier 2 and is integrally formed on the housing wall 21. A receiving opening 23 for receiving the rotor shaft is also formed at the housing bottom 22, which opening is coaxial with the longitudinal center axis 3.

Fig. 3 and 4 show a sectional view of the stator 1 at the housing base 22. For rotationally fixing the coil carrier 2 in the housing 20, the stator 2 has a fixing device 24 having a first fixing contour 25a and a second fixing contour 25 b. The first fastening contour 25a here comprises a plurality of fastening projections 26a which project radially inward from the housing wall 21 and are integrally formed only in the region of the housing base 22 at the housing wall 21 and at the housing base 22. The second fastening contour 25b comprises a plurality of fastening recesses 26b oriented radially inward, which are shaped at the coil carrier 2 toward the housing wall 21. The fixing projection 26a is complementarily shaped to the fixing recess 26b and radially engages therewith. The fastening projections 26a and the fastening recesses 26b are arranged so as to be distributed uniformly in the circumferential direction and in this case the coil carrier 2 engages the housing 20 over its entire circumference. The torque acting on the coil carrier 2 can thereby be absorbed uniformly.

Fig. 5 shows a sectional view of one fixing projection 26a and one fixing recess 26b of the fixing device 24. An inner circumferential gap 27, which preferably has a width of 75 μm to 125 μm, is formed between the fixing recess 26b and the fixing projection 26a engaging with the fixing recess 26 b. The circumferential gap 27 can simplify the arrangement of the coil carrier 2 in the housing 20 and can compensate for manufacturing tolerances. As is also shown in fig. 3 and 4, the securing device 24 can prevent the coil carrier 2 from rotating clockwise and counterclockwise in the circumferential direction.

According to fig. 3 to 5, the fastening recesses 26b are each formed by two half-recesses 29 at the contact points 28 of adjacent body segments 4. The half-recesses 29 are shaped in the insulating carrier 5 of the adjacent body section 4 and are arranged facing one another. The number of fastening recesses 26b in the coil carrier 2 is therefore determined by the number of body sections 4 or contact points 28 of the coil carrier 2. The number of fastening projections 26a at the housing 20 corresponds, as appropriate, to the number of body sections 4 in the coil carrier 2.

Fig. 6 and 7 show views of the coil carrier 2 in the stator 1 according to the invention from the side of the switch end 10 facing the axial direction. The coil carrier 2 has body sections 4 which are arranged distributed in the circumferential direction around the longitudinal center axis 3 and which abut one another at contact points 28. Each individual segment 4 comprises an insulating carrier 5 and to a conductor core component 6 which is partially surrounded by the insulating carrier 5. A winding overhang 8 for a stator coil 9, not shown here, is integrally formed on the wraparound plate 7 of the insulating carrier 5, said winding overhang projecting radially inward from the wraparound plate 7.

The respective contact points 28 of adjacent body segments 4 are each provided with a fastening recess 26b of the fastening device 24. The fastening recesses 26b are formed by adjacent mutually facing half-recesses 29 in the circumferential plates 7 of adjacent insulating carriers 5 and extend in an axial groove-like manner over the entire height of the respective circumferential plate 7. The conductor core parts 6 adjacent to one another have radial projections 30 which extend axially over the entire height of the respective conductor core part 6. The half-protrusions 30 of the respective conductor core parts 6 engage radially inwardly into the half-recesses 29 of the respective insulating carriers 5 and form fixing projections 26c, respectively. The fixing projections 26c axially close the respective fixing recesses 26b formed by the half recesses 29 over the entire height of the respective conductor core parts 6. According to fig. 1, the height of the conductor core part 6 is smaller than the height of the insulating carrier 5, so that the respective fixing recess 26b remains open on both sides. Subsequently, the respective fastening projections 26a at the housing base 22 engage in the fastening recesses 26b in the region of the housing base 22 and are arranged axially adjacent to the respective fastening projections 26c in the respective fastening recesses 26 b.

The half-protrusion 30 of each conductor core part 6 of the adjacent body section 4 also has an axial protrusion 31a and a complementary axial groove 31 b. The axial projections 31a engage in the axial grooves 31b over the entire height of the conductor core part 6 in the circumferential direction and fix the adjacent body sections 4 radially to one another. Adjacent body sections 4 can be fixed to each other at the half-bulges 30 of the respective conductor core parts 6 by ultrasonic welding. The axial grooves 32 in the individual conductor core parts 6 serve here not only for simplified handling of the conductor core parts 6 during the production of the stator 1, but also for additional positive fixing of the coil carrier 2 in the housing 20.

Furthermore, a second positive-locking contour 18b, which in this exemplary embodiment comprises a plurality of recesses 33b, is formed in each body section 4. According to fig. 1, the first positive-fit contour 18a of the insulator 15 axially engages with some of the recesses 33b of the second positive-fit contour 18 b. In this way, the insulating body 15 is fixed to the coil carrier 2 in a form-fitting manner. Furthermore, each body section 4 of the coil carrier 2 has a cutout 34, which is oriented radially outward and extends axially. According to fig. 1, the contact end 11a or the contact end 11b of the respective stator coil 9 is fixed in the respective cutout 34 in a partially positive and/or material-fitting manner. The respective contact ends 11a and 11b are oriented axially through the cutout 34 of the coil carrier 2 toward the axial switch end 10 and can be simply brought into electrical contact with one another.

Fig. 8 shows a view of the insulating carrier 5 from the side of the switch end 10 facing the axial direction and fig. 9 shows one axial component of the insulating carrier 5. The insulating carrier 5 can be produced, for example, from an electrically insulating plastic in a plastic injection molding method. Subsequently, the axial component of the insulating carrier 5 comprises conductor core components 6 axially on both sides, thereby forming the body section 4 of the coil carrier 2. As already explained with reference to fig. 6 and 7, the insulating carrier 6 has a recess 33b and a cutout 34 of the second positive-locking contour 18 b. The two half recesses 29 form, with the adjacent half recess 29 of the insulating carrier 5, on both sides a fixing recess 26b in the coil carrier 2. According to fig. 1, one of the stator coils 9 of the stator 1 is wound at a winding boss 8 protruding radially inward from the surrounding plate 7.

Fig. 10 shows a view of the interconnection means 12 with the contact strip 13, which is partially surrounded by an insulator 15. A view of the interconnect 12 is shown in fig. 11 and 12. Fig. 13 to 15 show views of the contact strip 13. The contact strips 13 are flat and elongate and bridge the distance between the contact ends 11a of the stator coils 9 to be contacted according to fig. 10. The contact strip 13 is expediently made of an electrically conductive material, for example copper, and the contact end 11a is fastened to the contact strip 13 in an electrically conductive manner.

According to fig. 11 and 12, the contact strip 13 has a central overlapping section 35, to the two sides of which receiving sections 36 are connected. In the overlap section 35, the contact strips 13 which are axially adjacent to the longitudinal center axis 3 overlap one another and can fix the contact ends 11a of the stator coils 9 to the receiving section 26. The contact strips 13 are arranged in the overlap section 35 at an angle α to one another in a plane radial to the longitudinal mid-axis 3 in order to accommodate the contact ends 11a of adjacent stator coils 9.

The receiving sections 36 of the contact strips 13 lie in receiving planes 37 which are jointly perpendicular to the longitudinal mid axis 3. For this purpose, step sections 38 are formed between the receiving section 36 and the respective overlapping sections 35 at the upper contact strip 13a and the lower contact strip 13c, respectively. The central contact strip 13b has no step sections 38 and is located in the receiving plane 37. The corresponding step portion 38 axially offsets the connected receiving portion 36 relative to the longitudinal center axis 3, so that at least the receiving portion 36 that contacts the belt 13 lies in the receiving plane 37. In contrast, the overlapping sections 35 remain axially offset from one another, so that the contact strips 13 do not have direct contact with one another. According to fig. 10, the interconnection means 12 with the contact strips 13 is partially surrounded by an insulator 15, so that the contact strips 13 are separated and electrically insulated from each other in the insulator 15 by the electrically insulating material of the insulator 15.

The contact strips 13 each have an axially aligned coupling projection 39 in the receiving section 36, which projection projects from the respective contact strip 13. The coupling projections 39 are formed from the material of the contact strip 13 and are arranged facing away from the coil carrier 2, as shown in fig. 10. A receptacle 40 is formed around the coupling projection 39 in the receptacle section 36, in which the respective contact end 11a is radially received and is arranged to bear against the coupling projection 29. The respective contact ends 11a are fastened to the coupling lugs 39 in a material-fitting manner, preferably by gas welding. Furthermore, axially oriented phase connection pins 14 are fastened to the respective contact strips 13 in a material-fitting manner, preferably by resistance welding, away from the coil carrier 2. The respective contact strips 13 can be made of copper, for example, and the respective phase connection pins 14 are coated with a nickel-tin layer.

Fig. 13 shows a view of the upper contact strip 13a, fig. 14 shows a view of the middle contact strip 13b and fig. 15 shows a view of the lower contact strip 13 c. As explained with reference to fig. 10 to 12, the upper contact strip 13a and the lower contact strip 13c each have an overlapping section 35, a receiving section 36 and a step section 38. In contrast, the central contact strip 13b does not have a step section 38, and the overlap section 35 enters directly into the receiving section 37 on both sides. The

intermediate contact strips

13a, 13b and 13c can be produced, for example, by stamping. Coupling projections 39 and receptacles 40 for receiving and securing the respective contact ends 11a are formed in the receiving sections 36. The phase connection pins 14 are each secured to the respective phase connection strip 13 in a material-to-material manner, and an external current source can be connected to said phase connection pins.

Fig. 16 shows a view of the insulating body 15 in the stator 1 and fig. 17 shows the insulating body 15 arranged at the coil carrier 2. The insulating body 15 here partially surrounds the interconnection device 12 with the contact strips 13 and supports the axially spaced apart contact strips 13 against one another. Suitably, the receiving section 36 of the phase U, V, W and the phase terminal pin 14 protrude from the insulator 15 such that the contact end 11a can be electrically contacted with the interconnection means 12 and the stator 1 can be connected to an external current source. Furthermore, the insulating body 15 has an insulating cover 19 which insulates the contact ends 11b of the stator coils 9 which are in electrical contact with one another to the outside according to fig. 17. The insulating cover 19 is integrally formed on the carrier ring 16 and is oriented radially outward.

The carrier rings 16 of the insulating body 15 are fixed at a distance to the coil carrier 2. For this purpose, the retaining arms 17 are integrally formed at the carrier ring 16. The retaining arms 17 each have a radial section 41 and an axial section 42. The radial section 41 is directly connected to the carrier ring 16 and is oriented radially outward. The axial section 42 is directly connected to the radial section 41 and extends axially towards the coil carrier 2. A first positive-fit contour 18a in the form of a projection 33a is formed at the axial section 42 of the respective retaining arm 17, as shown in fig. 16. The protrusions 33a of the first positive-fit contour 18a axially engage with the recesses 33b of the second positive-fit contour 18b of the coil carrier 2 according to fig. 17. Additionally, the projection 33a can be secured in the recess 33b in a material-locking manner. The insulating body 15 has a total of four retaining arms 16, which are distributed uniformly in the circumferential direction on the carrier ring 16.

Fig. 18 shows a schematic illustration of a possible interconnection of the stator coils 9 in the stator 1. Fig. 19 shows a corresponding view of the interconnected stator coils 9 in the stator 1. The stator coils 9 are interconnected into a first star circuit 43 having three

first phase terminals

43U, 43V, 43W and a second star circuit 44 parallel to the first star circuit 43 having three

second phase terminals

44U, 44V, 44W. Each of the

first phase terminals

43U, 43V, and 43W and each of the

second phase terminals

44U, 44V, and 44W are formed by the contact end portion 11a of the corresponding stator coil 9 according to fig. 19. Here, the contact strips 13 of the interconnection device 12 contact the contact ends 11a of the six stator coils 9 and thereby electrically contact the

phase terminals

43U, 43V, 43W and 44U, 44V, 44W in pairs and correspondingly with each other. The two

star circuits

43 and 44 each have a

neutral point

43N and 44N, respectively, in which the three contact ends 11b of the stator coils 9 are in electrical contact with each other. The contact ends 11b in the

neutral points

43N and 44N can be welded or soldered to one another and are electrically insulated to the outside by the insulating cover 19 of the insulator 15 according to fig. 19.

Claims

1. A stator (1) for a three-phase electric motor,

-wherein the stator (1) has a hollow-cylindrical coil carrier (2) and a plurality of stator coils (9) which are respectively wound on winding projections (8) of the coil carrier (2) and which are oriented parallel to a longitudinal center axis (3) of the coil carrier (2) and are arranged distributed around the longitudinal center axis (3) within the coil carrier (2),

-wherein at least one end contact unit is formed at an axial switching end (10) of the coil carrier (2), said at least one end contact unit comprising contact ends (11a) of a plurality, in particular six, stator coils (9) of the stator (1) for three phases (U, V, W), and

-wherein the respective contacting ends (11a) of the stator coils (9) are electrically contacted in a corresponding manner in the end contacting units by means of an interconnecting device (12),

it is characterized in that the preparation method is characterized in that,

-the interconnection device (12) has three elongate, shaped contact strips (13) which are oriented at the axial switching end (10) perpendicularly to the longitudinal mid-axis (3) and overlap axially spaced apart from one another, and

-each of the contact strips (13) is in electrical contact with each other in the end contact unit, in particular in pairs and correspondingly with the contact ends (11a) of the stator coils (9).

2. The stator as set forth in claim 1, wherein,

it is characterized in that the preparation method is characterized in that,

each contact strip (13) has a central overlapping section (35) to which receiving sections (36) of the contact ends (11a) of the stator coils (9) are respectively connected on both sides, and

one of the contact strips (13) and the other contact strip (13) are arranged in the overlapping section (35) at an angle (a) relative to each other in a plane radial to the longitudinal mid-axis (3).

3. The stator as set forth in claim 2, wherein,

it is characterized in that the preparation method is characterized in that,

the receiving sections (36) of the respective contact strips (13) are located in a common receiving plane (37) perpendicular to the longitudinal center axis (3).

4. The stator according to claim 2 or 3,

it is characterized in that the preparation method is characterized in that,

a step section (38) is provided between at least one of the receiving sections (36) and the overlapping section (35) of the respective contact strip (13), said step section axially offsetting the receiving section (36) relative to the overlapping section (35).

5. The stator as set forth in claim 4, wherein,

it is characterized in that the preparation method is characterized in that,

-an upper one (13a) of the axially spaced apart contact strips has downwardly offset receiving sections (36) on both sides and a lower one (13c) of the axially spaced apart contact strips has upwardly offset receiving sections (36) on both sides, and

-the middle one (13b) of the axially spaced contact strips has no step sections (38) on both sides.

6. The stator according to any one of claims 2 to 5,

it is characterized in that the preparation method is characterized in that,

the respective contact end (11a) is secured in the receiving section (36) to the respective contact strip (13) in a material-fitting manner, preferably by gas welding.

7. The stator as set forth in claim 6, wherein,

it is characterized in that the preparation method is characterized in that,

the receiving section (36) of each contact strip (13) has at least one axially oriented coupling projection (39) which projects from the respective contact strip (13) and against which the respective axially oriented contact end (11a) of each stator coil (9) bears over a large area.

8. The stator according to any one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the axially oriented phase connection pins (14) are integrally formed away from the coil carrier (2) or are fastened to the respective contact strips (13) by means of a material fit, preferably by means of resistance welding.

9. The stator according to any one of claims 1 to 8,

it is characterized in that the preparation method is characterized in that,

-the stator coils (9) are interconnected in a first star circuit (43) with three first phase terminals (43U, 43V, 43W) and a second star circuit (44) parallel to the first star circuit (43) with three second phase terminals (44U, 44V, 44W),

-each of the first phase terminals (43U, 43V, 43W) and each of the second phase terminals (44U, 44V, 44W) is formed by the contact end portion (11a) of the corresponding stator coil (9), and

-said contact strip (13) and said contact end (11a) of the respective stator coil (9) are in electrical contact with each other, respectively.

10. The stator according to any one of claims 1 to 8,

it is characterized in that the preparation method is characterized in that,

-the stator coils (9) are interconnected in a triangular circuit with three phase terminals,

-each of said phase terminals is formed by said contact end (11a) of the corresponding stator coil (9), and

11. The stator according to any one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the stator (1) has an electrically insulating insulator (15) which surrounds the interconnection device (12) at least in some regions in a form-fitting manner and electrically insulates the contact ends (11a) which are electrically contacted with one another via the interconnection device (12) from one another in a corresponding manner.

12. The stator as set forth in claim 11, wherein,

it is characterized in that the preparation method is characterized in that,

the insulating body (15) is made of plastic and is extruded around the interconnection device (12) by means of a plastic injection molding method.

13. The stator according to claim 11 or 12,

it is characterized in that the preparation method is characterized in that,

the insulating body (15) has an annular support ring (16) which radially surrounds the longitudinal center axis (3) and is fastened at the axial switching end (10) to the coil carrier (2) at a distance in a plane radial to the longitudinal center axis (3).

14. The stator as set forth in claim 13, wherein,

it is characterized in that the preparation method is characterized in that,

at least one insulating cover (19) is integrally formed on the carrier ring (16), said cover surrounding at least some contact ends (11b) of the stator coils (9), in particular contact ends (11b) forming the star point of a star circuit (44), at least in some regions in a form-fitting manner at the axial switching end (10) and electrically insulating said contact ends to the outside.

15. The stator according to claim 13 or 14,

it is characterized in that the preparation method is characterized in that,

-integrally forming or fixing a plurality of retaining arms (17) at the carrier ring (16) in a form-fitting and/or material-fitting manner, each having a radial section (41) extending radially outward connected to the carrier ring (16) and an axial section (42) extending axially towards the coil carrier (2) connected to the radial section (41), and

-the retaining arm (17) is fixed to the coil carrier (2) by means of the respective axial section (42) in a form-fitting and/or material-fitting manner.

16. The stator as set forth in claim 15, wherein,

it is characterized in that the preparation method is characterized in that,

-a first positive-fit contour (18a) is shaped at the axial section (42) and a second positive-fit contour (18b) is shaped at the coil carrier (2), the first and second positive-fit contours being in axial and positive-fit engagement with each other, and

-the first or second positive contour (18a, 18b) is an integrally formed protrusion (33a) and the second or first positive contour (18a, 18b) is a recess (33b) or cut-out complementary to the protrusion (33 a).

17. The stator according to claim 15 or 16,

it is characterized in that the preparation method is characterized in that,

-the plurality of retaining arms (17) are evenly distributed at the carrier ring (16) in circumferential direction, and/or

-the plurality of retaining arms (17) are provided at the carrier ring (16) in the region of the phase terminal pin (14).

18. The stator according to any one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the stator (1) has a housing (20) having a housing wall (21) surrounding the longitudinal mid-axis (3) and having a housing bottom (22) axially closing the housing wall (21),

-the coil carrier (2) is fixed coaxially and by means of a fixing device (24) having a first fixing profile (25a) and a second fixing profile (25b) in the housing (20),

-the first fixing contour (25a) comprises a plurality of fixing projections (26a) projecting radially inwards from the housing wall (21), which are arranged distributed in the circumferential direction only in the region of the housing bottom (22),

-the second fixing contour (25b) comprises a plurality of radially inwardly directed fixing recesses (26b) which are shaped at the coil carrier (2) towards the housing wall (21) and which are shaped

-said fixing projection (26a) is complementarily shaped and radially engaged with said fixing recess (26 b).

19. The stator as set forth in claim 18, wherein,

it is characterized in that the preparation method is characterized in that,

an inner circumferential gap (27) is formed between each of the fastening recesses (26b) and the fastening projection (26a) which engages in each case with the fastening recess (26b), said circumferential gap preferably having a width of 75 μm to 125 μm.

20. The stator according to claim 18 or 19,

it is characterized in that the preparation method is characterized in that,

-the coil carrier (2) has a plurality of body sections (4) which each carry a stator coil (9), which are arranged distributed in the housing (20) in the circumferential direction around the longitudinal center axis (3), and

-each of the body segments (4) has an electrically insulating part (5) with a surrounding plate (7) and with a winding projection (8) directed radially inwards from the surrounding plate (7) for the respective stator coil (9); and an electrically conductive conductor core component (6) at least partially surrounded by the insulating carrier (5).

21. The stator as set forth in claim 20, wherein,

it is characterized in that the preparation method is characterized in that,

the fixing recesses (26b) are each formed at the contact points (28) of adjacent body sections (4) by two half-recesses (29) which are each formed toward one another at adjacent body sections (4).

22. The stator as set forth in claim 21, wherein,

it is characterized in that the preparation method is characterized in that,

-the half-recesses (29) are shaped in the surrounding plate (7) of the respective insulating carrier (6) and extend axially groove-like over the entire height of the surrounding plate (7),

-shaping a semi-bulge (30) radially in each conductor core part (6), which semi-bulge extends axially over the entire height of the respective conductor core part (6), and

-the half-projections (30) of the conductor core part (6) engage radially into the half-recesses (29) of the surrounding plate (7) and close the fixing recesses (26b) axially over the entire height of the respective conductor core part (6).

23. The stator as set forth in claim 22, wherein,

it is characterized in that the preparation method is characterized in that,

the half-protrusion (30) of each conductor core part (6) is axially adjacent to the corresponding fixing protrusion (26a) in each fixing recess (26 b).

24. The stator according to claim 22 or 23,

it is characterized in that the preparation method is characterized in that,

the half-projections (30) of the individual conductor core parts (6) of adjacent body sections (4) are joined in a material-fit manner in the circumferential direction over the entire height of the conductor core part (6) via axial projections (31a) and complementary axial grooves (31 b).

25. The stator according to any one of claims 22 to 24,

it is characterized in that the preparation method is characterized in that,

the adjacent body sections (4) are fixed to one another in a material-fit manner, preferably by ultrasonic welding, on the half-elevations (30) of the respective conductor core part (6).

26. The stator according to any one of claims 20 to 25,

it is characterized in that the preparation method is characterized in that,

-each insulating carrier (5) is composed of plastic and is injection-molded at the respective conductor core part (6) in a plastic injection-molding process, or

-each insulating carrier (5) is formed in two parts and surrounds the respective conductor core part (6) at least partially axially on both sides and in a form-fitting manner.

27. The stator according to any one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the coil carrier (2) has at least one cutout (34) oriented radially outward, in which a contact end (11a) or a contact end (11b) of each stator coil (9) is respectively fixed in an at least partially form-fitting manner.