Stator system for an electric motor

Abstract

A stator system for an electric motor has multiple coil formers and stator windings that are wound on the coil formers. The stator windings are distributed over the circumference of the stator system and are arranged to form a substantially circular stator star. A number of the stator windings are electrically insulated in the axial direction in each case by way of a phase separator. The stator windings in each case of two coil formers are electrically connected as a coil pair in an electrically conductive manner by a conductor track. The conductor track is retained by a separating web that is arranged in the axial direction above the allocated phase separator and that extends in a radial direction.

Claims

1. A stator system for an electric motor, comprising: a plurality of coil formers; stator windings wound on said coil formers, said stator windings being distributed over a circumference of the stator system and disposed to form a substantially circular stator star having an axis extending substantially coaxially with an axis of the electric motor; a plurality of conductor tracks, each said conductor track electrically connecting said stator windings of at least two respective said coil formers to form a coil pair; a plurality of phase separators disposed to electrically insulate respective said stator windings in an axial direction, each said phase separator being disposed between at least one of said conductor tracks and a respective said stator winding; and a plurality of separating webs, each said separating web assembled to a respective said coil former and retaining at least one of said conductor tracks, each said separating web being disposed in an axial direction above a respective said phase separator, and each said separating web having at least one recess formed therein that is open towards the respective said phase separator and is configured to receive said at least one of said conductor tracks.

2. The stator system according to claim 1, wherein each said separating web is oriented to extend radially.

3. The stator system according to claim 1, wherein each said separating web is latched to the respective said coil former.

4. The stator system according to claim 1, wherein each said phase separator extends substantially over an entire axial length and a radial width of the respective said coil former.

5. The stator system according to claim 1, wherein each said separating web, in an assembled state, extends substantially over an entire radial width of the respective said coil former of said stator star.

6. The stator system according to claim 1, wherein said at least one recess, in cross section, is a circular segment greater than 180°.

7. The stator system according to claim 1, wherein said recess in each said separating web is an inclined recess.

8. The stator system according to claim 1, wherein said at least one recess is one of a plurality of recesses that are spaced apart from one another in a radial direction.

9. The stator system according to claim 1, wherein each said separating web is latched to the respective said coil former by way of a latching connection comprising a latching contour formed in the respective said coil former and provided with latching hooks, and wherein said separating web lies in said latching contour.

10. The stator system according to claim 1, which comprises a securing element formed onto each said separating web and lying radially against a corresponding stop surface of the respective said coil former.

11. The stator system according to claim 1, wherein each said separating web is articulated to the respective said coil former via a film hinge.

12. An electric motor, comprising a stator system according to claim 1.

13. The electric motor according to claim 12, configured as a servo drive of a motor vehicle steering system.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) FIG. 1 illustrates a plan view of the stator star of a six-pole stator system comprising twelve coil formers having stator windings, wherein in each case two coil formers are embodied with a conductor track to a coil pair as a magnetic pole;

(2) FIG. 2 is a perspective view of a coil pair;

(3) FIG. 3 is a perspective view of a detail of the coil former of the stator star having phase separators and separating webs for galvanically separating the conductor tracks and the stator windings;

(4) FIG. 4 is a perspective view of a separating web having recesses that are arranged in an inclined manner;

(5) FIG. 5 illustrates a detail of the latching connection of the separating web showing the radial recesses of the coil former, the recesses being incorporated in the coil former and provided with latching hooks; and

(6) FIG. 6 is a view of a detail of the latching connecting of the separating web in the form of a film hinge.

DETAILED DESCRIPTION OF THE INVENTION

(7) Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown a stator system 2 for an electric motor. The latter is not illustrated in detail. The stator system 2 has twelve coil formers 4 as individual stator teeth that comprise coils 6 or stator windings that are wound on the coil formers.

(8) The coil formers 4 are arranged to form an annular, circular stator star 8. In the assembled state, a rotor of the electric motor is arranged inside the stator star 8, the rotor being rotatably mounted in the magnetic exciter field of the stator system 2. Each two coil formers 4 with the respective stator windings 6 are electrically connected in an electrically conductive manner by means of a conductor track 10 and are combined to form a coil pair 12 as one assembly unit. The respective conductor track 10 is a component of the corresponding coil winding or rather stator winding 6. By way of example, in each case only one coil pair assembly unit of this type is provided in the figures with reference numerals.

(9) During operation of the electric motor, electric current flows through the six cascading coil pairs 12 and the coil pairs form six magnetic pole regions of the stator system 2. The coil pairs 12 of the stator star 2 are electrically switched one to the other in series or in parallel. The conductor track 10 of a coil pair 12 extends essentially in each case over the coil former 4 of two further coil pairs 12.

(10) FIG. 2 illustrates in detail an exemplary embodiment of a coil pair 12. The stator windings 6 comprise in each case two connection ends, namely a contacting end 14 and a connecting end that extends as a conductor track 10 between the coils. The stator windings 6 of the two coil formers 4 and also the conductor track 10 are embodied in one piece from a copper wire that is wound around the coil formers 4 by means of individual tooth-winding technology. In this embodiment, six stator windings 6 are wound around each coil former 4 of a coil pair 12. The coil formers 4 are essentially rectangular injection molded components that are embodied from an electrically non-conductive synthetic material and comprise in the radial direction—towards the inner and outer circumference of the stator star 2—a retaining wall 16. The coil former 4 consequently comprises in the axial direction an essentially H-shaped cross-section, wherein the stator windings 6 are wound around the horizontal H-limb.

(11) The contacting ends 14 are contacted by means of a pressing process or the like in a suitable manner by the adjacent coil pairs 12 of the identical phase by way of a weld or solder connection. The stator system 2 comprises essentially —as is evident in FIG. 1—an upper coil pair assembly unit 18 and a lower coil pair assembly unit 20, wherein the contacting ends 14 of the respective outer coil former 4 of the respective coil assembly unit 18, 20 is coupled to a control device, not illustrated in detail, and an energy source in order to control and supply the stator system 2. The coil pair assembly units 18, 20 comprise in each case three coil pairs 12 that are switched one to the other in series in such a cascading electric manner that during operation of the coil pair group 18, 20 each conductor track 10 carries a different current phase.

(12) A phase separator 22 is allocated in each case to the coil formers 4 in the region of the conductor tracks 10 in order to galvanically separate the current phases between a conductor track 10 and the stator windings 6 of the coil pairs 12. The phase separators 22 insulate the stator windings 6 in the axial direction and extend—as is evident in FIG. 3—essentially over the entire axial length and the radial width of the coil former 4. The conductor tracks 10 of the coil pairs 12 are routed on the phase separators 22 essentially in a tangentially manner towards the stator star 8, wherein multiple conductor tracks 10 are arranged adjacent to one another on a phase separator 22 preferably in the form of a triple spiral.

(13) The conductor tracks 10 of four inner coil formers 4 of the coil assembly units 18, 20 are in addition fixedly clamped to a separating web 24 that is arranged in a radial manner with respect to the stator star 8. The separating web 24 is produced from an electrically non-conductive synthetic material and extends essentially over the entire radial width of the respective coil former 4 of the stator star 8.

(14) FIG. 4 illustrates the construction of a separating web 24 of this type having an essentially rectangular-shaped separating web body 26, two recesses 28 for receiving the conductor tracks 10 and two fixing webs 30 that are formed as one thereon as radial securing elements or stop elements. The fixing webs 30 are arranged in a perpendicular manner with respect to the separating web body 26 at the end that is on the outer circumference side in the assembled state so that the separating web 24 is essentially T-shaped. The recesses 28 are aligned in the assembled state towards the phase separator 22 and comprise in their cross-section a circular segment that is greater than 180° so that the conductor tracks 10 can be clipped into the recesses 28 and are retained in an operationally secure manner.

(15) The recesses 28 are spaced apart in a radial manner with respect to one another and extend in an inclined manner towards the separating web 24 so that the conductor tracks 10 that are arranged tangentially in a spiral-like manner can be clipped without any problems into the separating web 24. The separating web 24 galvanically spatially separates and securely retains the conductor tracks 10 that are preferably embodied as multi-stranded copper wires so that phase-to-phase short circuits between adjacent conductor tracks 10 as a result of possible damage to their individual wires are reliably avoided.

(16) The separating webs 24 can be fastened by means of a latching device 32 of the retaining walls 16 to the coil formers 4 in a clamped manner without becoming damaged. FIG. 5 illustrates in greater detail a detail of the latching device 32. For this purpose, the retaining walls 16 comprise an essentially U-shaped latching contour 34 on the separating web-side on the inner and outer circumference of the stator star 8. Two latching hooks 36 are arranged in each case inwardly facing one another and in the form of an overhang on the upper ends of the vertical U-limbs and in the clipped-in, assembled state the latching hooks fix the separating web 24 in the axial direction. The fixing webs 30 of the separating web 24 lie in a radial manner in the assembled state against the vertical U-limbs of the latching contour 34 towards the outer circumference of the stator star 8. As a consequence, the form lock of the latching device 32 is improved, as a consequence of which it is ensured that the phases are separated in a particularly reliable manner even in the case of shocks and vibrations during operation of the electric motor.

(17) FIG. 6 illustrates an alternative embodiment of the coil former 4 and the separating web 24 in the form of a film hinge 38. In this embodiment, the latching device 32 is replaced at the outer circumference of the stator star 8 by the film hinge 38. The coil former 4 and the separating web 24 are embodied in this embodiment as a common injection molded component, wherein the separating web 24 can be clipped as a hinge bracket at the free end side into the latching contour 34 at the inner circumference.

(18) The invention is not limited to the above described exemplary embodiments. On the contrary, the person skilled in the art can also derive therefrom other variants of the invention without departing from the subject of the invention. In particular, all the individual features that are described in connection with the different exemplary embodiments can moreover also be combined with one another in other ways without departing from the subject of the invention.

(19) The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention:

(20) 2 Stator System

(21) 4 Coil Former

(22) 6 Stator Winding

(23) 8 Stator Star

(24) 10 Conductor Track

(25) 12 Coil Pair

(26) 14 Contacting End

(27) 16 Retaining Wall

(28) 18, 20 Coil Pair Assembly Unit

(29) 22 Phase Separator

(30) 24 Separating Web

(31) 26 Separating Web Body

(32) 28 Recess

(33) 30 Fixing Web

(34) 32 Latching Device

(35) 34 Latching Contour

(36) 36 Latching Hook

(37) 38 Film Hinge