Synchronous machine

Abstract

The invention relates to an inductively electrically excited synchronous machine (1) which has a machine stator (2), a machine rotor (3) and a rotary transformer (7) comprising a transformer stator (8), which is fixed to the stator and has a primary coil (10), and comprising a transformer rotor (9), which is fixed to the rotor and has a secondary coil (11). The transformer stator (8) has a transformer housing (13) comprising a housing lower part (14) and an axially adjoining housing upper part (15) which delimit a housing interior (16) in which the transformer rotor (9) and the primary coil (10) are arranged. The assembly of the synchronous machine (1) can be simplified in the region of the rotary transformer (7) if: the machine stator (2) has a plurality of axial centering openings (17) distributed in the circumferential direction (U); the housing lower part (14) has a plurality of axial through-openings (18) distributed in the circumferential direction (U); the housing upper part (15) has a plurality of axially projecting sleeves (19) distributed in the circumferential direction (U); and the centering openings (17), the through-openings (18) and the sleeves (19) are adapted to one another such that, when the machine stator (2), housing lower part (14) and housing upper part (15) are in a predetermined rotational position, the sleeves (19) each extend axially through a through-opening (18) into a centering opening (17).

Description

[0001] Synchronous machine

[0002] The present invention relates to an inductively electrically excited synchronous machine according to the preamble of claim 1.

[0003] A generic synchronous machine is known, for example, from DE 10 2021 212 205 A1 and comprises a machine stator, a machine rotor, a rotary transformer, and a rectifier. The machine stator typically has a stator winding. The machine rotor is mounted on the machine stator so as to be rotatable about a rotational axis and has a rotor shaft with a rotor winding. The rotary transformer serves to supply the rotor winding with electrical energy and has a stator-fixed transformer stator with a primary coil and a rotor-fixed transformer rotor with a secondary coil. The rectifier is arranged so as to be fixed to the rotor and serves to electrically couple the secondary coil to the rotor winding. The transformer stator has a transformer housing, which has a lower housing part and an upper housing part axially adjacent thereto.The lower housing part and the upper housing part define a housing interior in which the transformer rotor is arranged to rotate about the rotation axis and in which the primary coil is arranged fixed to the stator.

[0004] Other synchronous machines with rotary transformers are known from DE 10 2017 214 776 A1 and from US 5 519 275 A.

[0005] In a multi-part transformer housing, the lower and upper housing sections must be precisely fitted to one another and to the transformer stator in order to achieve the highest possible efficiency for the induction effect between the primary and secondary coils. Narrow gaps are particularly advantageous in this regard. In an axially constructed rotary transformer, an axial gap is provided between the primary and secondary coils, which is configured to be as small as possible to achieve an efficient induction effect. Since the transformer housing is fixed to the stator, a corresponding radial gap must also be maintained between the rotor shaft of the machine rotor and the transformer housing, whereby a small gap is also aimed for here to ensure a compact design. Taking these boundary conditions into account, the assembly of the synchronous machine in the area of ​​the rotary transformer is comparatively complex.

[0006] In the present context, a "configuration" is synonymous with a "design" and / or "arrangement", so that the phrase "configured so that" is synonymous with the phrase "designed and / or arranged so that".

[0007] The present invention addresses the problem of providing an improved or at least a different embodiment for such a synchronous machine, which is characterized in particular by simplified assembly in the area of ​​the rotary transformer.

[0008] This problem is solved according to the invention by the subject matter of the independent claim. Advantageous embodiments are the subject matter of the dependent claims.

[0009] The present invention is based on the general idea of ​​configuring or coordinating the machine stator, the lower housing section, and the upper housing section in such a way that, during assembly, a predetermined rotational position between the machine stator, the lower housing section, and the upper housing section is automatically established, as well as the centering of the lower housing section and the upper housing section relative to the rotational axis. This significantly simplifies assembly.

[0010] Specifically, it is proposed to equip the machine stator with a plurality of axial centering openings distributed in the circumferential direction, to equip the lower housing part with a plurality of axial through-openings distributed in the circumferential direction, and to equip the upper housing part with a plurality of axially projecting sleeves distributed in the circumferential direction. Furthermore, it is proposed to coordinate the centering openings, the through-openings, and the sleeves such that, in a predetermined rotational position between the machine stator, lower housing part, and upper housing part, the sleeves each penetrate axially through one of the through-openings and into one of the centering openings. This ensures that the upper housing part can only be attached to the lower housing part in the predetermined rotational position, and that the transformer housing can only be attached to the machine stator in the predetermined rotational position.The positioning of the centering holes and the sleeves also enables centering with respect to the rotation axis.

[0011] According to an advantageous embodiment, the centering holes, the through holes, and the sleeves can be coordinated with one another such that the sleeves only penetrate axially through one of the through holes into one of the centering holes in a single, predetermined rotational position between the machine stator, the lower housing section, and the upper housing section. For example, a specific rotational position relative to the machine stator may be required for proper assembly of the transformer housing's electrical connections. The proposed coordination of the components allows this rotational position to be automatically found during assembly of the transformer housing. This also prevents assembly with an incorrect rotational position.

[0012] According to an advantageous embodiment, screws can be screwed through the sleeves into the machine stator. Using the screws, the transformer housing can be easily and securely fixed to the machine stator in the respective rotational position.

[0013] A preferred development is one in which the machine stator has an axial screw opening within each of the centering openings, which is arranged concentrically with the respective centering opening. Furthermore, a cross-section of the respective screw opening can be smaller than a cross-section of the respective centering opening. This allows the respective sleeve to penetrate the centering openings without hindering the insertion of the screw through the respective sleeve into the screw opening. The respective screw is then screwed into each such screw opening.

[0014] In another advantageous development, the respective screw can be provided with a screw head that presses the upper housing part against the lower housing part and the lower housing part against the machine stator. This ensures secure fixation. The screw head can be supported directly on the upper housing part or indirectly on the upper housing part via a washer.

[0015] The centering openings can expediently be cylindrical and have a circular inner cross-section. The through-openings can expediently be cylindrical and have a circular inner cross-section. The sleeves can expediently be hollow-cylindrical and have a circular inner cross-section and / or a circular outer cross-section.

[0016] In another advantageous embodiment, the machine stator can have an axial recess concentric with the centering openings, into which the housing base is axially inserted. This realizes an axially compact arrangement of the transformer housing in the synchronous machine.

[0017] An advantageous embodiment is one in which the housing base has a flange on which the through-holes are formed. The flange of the housing base simplifies the use of screws for securing the transformer housing to the machine stator. Such a flange requires little space in the axial direction, which makes it easy to implement an axially compact design.

[0018] According to an advantageous embodiment, the lower housing part can have a pot-shaped housing body which has a housing base and a circumferential housing wall. The flange of the lower housing part can be formed on the housing wall at an end of the housing wall remote from the housing base. Furthermore, the recess and the lower housing part can be coordinated with one another such that an axial gap is formed axially between the housing base and the machine stator within the recess and an annular circumferential radial gap is formed radially between the housing wall and the machine stator. The axial gap and the radial gap can be used to largely decouple the transformer housing from the machine stator. This can, for example, reduce the transmission of vibrations from the machine stator to the transformer housing.

[0019] According to another embodiment, the upper housing part can have a flange on which the sleeves are formed. Here, too, the use of a flange can support an axially compact design for the synchronous machine in the region of the rotary transformer. The flange of the upper housing part also simplifies the use of screws for fixing the transformer housing to the machine stator. Additionally or alternatively, the upper housing part can have a pot-shaped housing body which has a housing base and a circumferential housing wall. In this case, it can be provided in particular that the flange of the upper housing part is formed on the housing wall at an end of the housing wall remote from the housing base. In this way, in particular, the volume of the housing interior can be increased.

[0020] According to an advantageous embodiment, the sleeves can be formed from the same material or integrally on the upper housing part. This results in simple production of the upper housing part with the sleeves formed thereon. For example, the upper housing part can be manufactured as an injection-molded part made of plastic. Additionally or alternatively, the lower housing part can be manufactured as an injection-molded part made of plastic.

[0021] According to an advantageous embodiment, an inner cross-section of the respective through-opening and an outer cross-section of the respective sleeve can have the same nominal diameter. Additionally or alternatively, an inner cross-section of the respective centering opening and an outer cross-section of the respective sleeve can have the same nominal diameter. By using the same inner diameter for the outer cross-section of the sleeves and the inner cross-section of the through-openings on the one hand and / or the inner cross-section of the centering openings on the other hand, the desired rotational position between the housing parts on the one hand and between the transformer housing and the machine stator on the other hand can be realized with a high degree of precision. It is clear that the same nominal diameters can only be manufactured within the usual tolerances, so that the actual diameters or cross-sections can vary within the tolerances.

[0022] For the tolerances provided here, for example, a relatively tight clearance fit or a relatively tight transition fit are possible.

[0023] In order to be able to insert the sleeve more easily into the through-hole and then axially into the centering opening, the through-hole can have a chamfer at its free end leading up to the insertion.

[0024] In an advantageous embodiment, a ferrite core can be arranged in the transformer housing, fixed to the stator, surrounding the primary and secondary coils. The ferrite core can significantly improve the efficiency of the inductive interaction between the primary and secondary coils.

[0025] The ferrite core can be expediently split axially, with an upper core section located in the upper housing section and a lower core section located in the lower housing section. The axial division of the ferrite core allows the primary coil and the secondary coil to be easily arranged axially within the ferrite core.

[0026] For practical purposes, the rotor shaft of the machine rotor can penetrate concentrically into the transformer housing and support the transformer rotor inside the transformer housing. A complete axial penetration of the rotor shaft into the transformer housing is not required, but should not be ruled out.

[0027] The transformer rotor can expediently have a coil carrier that is attached to the rotor shaft of the machine rotor and on which the secondary coil is attached and / or formed. Using such a coil carrier, an axial design for the rotary transformer can be realized, in particular, in which the primary coil and the secondary coil are separated from each other by an axial gap.

[0028] Further important features and advantages of the invention emerge from the subclaims, from the drawings and from the associated description of the figures based on the drawings.

[0029] It is understood that the features mentioned above and those to be explained below can be used not only in the respective combination specified, but also in other combinations or on their own, without departing from the scope of the invention defined by the claims. Components mentioned above and to be mentioned below of a higher-level unit, such as a device, apparatus, or arrangement, which are designated separately, may form separate parts or components of this unit or be integral areas or sections of this unit, even if this is shown differently in the drawings.

[0030] Preferred embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description, wherein the same reference numerals refer to the same or similar or functionally identical components.

[0031] They show, schematically,

[0032] Figure 1 is an isometric view of a synchronous machine in the area of ​​a partially sectioned rotary transformer, Figure 2 is a longitudinal section of the synchronous machine in the area of ​​the rotary transformer,

[0033] Figure 3 is an isometric view in the area of ​​a sleeve of a housing upper part.

[0034] According to Figure 1, an inductively electrically excited synchronous machine 1 comprises a machine stator 2, which typically has a stator winding (not shown here). The synchronous machine 1 also has a machine rotor 3, which is mounted on the machine stator 2 for rotation about a rotation axis 4 and which has a rotor shaft 5 and a rotor winding 6. The rotation axis 4 defines an axial direction X, which runs parallel to the rotation axis 4, and a circumferential direction U, which revolves around the rotation axis 4. The radial direction is perpendicular to the rotation axis 4.

[0035] The synchronous machine 1 also has a rotary transformer 7, which serves to supply the rotor winding 6 with electrical energy. The rotary transformer 7 comprises a stator-fixed transformer stator 8 and a rotor-fixed transformer rotor 9. The transformer stator 8 has a primary coil 10, while the transformer rotor 9 has a secondary coil 11. The synchronous machine 1 is also equipped with a rotor-fixed rectifier 12, via which the secondary coil 11 is electrically coupled to the rotor winding 6. In the example in Figure 1, the rectifier 12 is formed on the transformer rotor 9. Alternatively, the rectifier 12 can also be arranged, for example, on an axial end face of a rotor lamination stack 48.

[0036] The transformer stator 8 has a transformer housing 13 which has a

[0037] A lower housing part 14 and an upper housing part 15 that axially rests against the lower housing part 14. The lower housing part 14 and the upper housing part 15 define a housing interior 16 in which the transformer rotor 9 with the secondary coil 11 is arranged so as to be rotatable about the rotation axis 4 and in which the primary coil 10 is arranged fixedly to the stator. The rotary transformer 7 has an axial structure such that the primary coil 10 and the secondary coil 11 are axially adjacent and separated from one another by an axial gap 49.

[0038] According to Figure 2, the machine stator 2 comprises a plurality of axial centering openings 17 distributed in the circumferential direction U, of which only one is visible in Figure 2. The lower housing part 14 has a plurality of axial through-openings 18 distributed in the circumferential direction U, of which only one is visible in Figure 2. The upper housing part 15 has a plurality of axially projecting sleeves 19 distributed in the circumferential direction U, of which only one is visible in Figure 2. Expediently, the same number of centering openings 17 as through-openings 18 and sleeves 19 are provided. The centering openings 17, the through-openings 18 and the sleeves 19 are coordinated with one another orconfigured such that, in a predetermined rotational position shown in Figure 2 between the machine stator 2, the lower housing part 14 and the upper housing part 15, the sleeves 19 each penetrate axially through one of the through openings 18 into one of the centering openings 17. In an advantageous

[0039] In this embodiment, it can even be provided that the centering openings 17, the through-openings 18 and the sleeves 19 are coordinated with one another in such a way that the sleeves 19 can only penetrate axially into one of the centering openings 17 through one of the through-openings 18 in a single predetermined rotational position between the machine stator 2, the lower housing part 14 and the upper housing part 15.

[0040] According to Figure 2, a screw 20 is also provided for each sleeve 19, through which the respective sleeve 19 is screwed into the machine stator 2, although only one of these can be seen in Figure 2. The machine stator 2 can expediently have an axial screw opening 21 within the respective centering opening 17, which is arranged concentrically to the respective centering opening 17, although only one of these can be seen in Figure 2. The respective screw 20 is screwed into such a screw opening 21. For this purpose, a screw shaft 22 has an external thread 23 which is complementary to an internal thread 24 which has the screw opening 21. The screw 20 can also have a screw head 25 which, in the example in Figure 2, is supported directly on the upper housing part 15.When screwed in, the screw head 25 presses the upper housing part 15 against the lower housing part 14 and the lower housing part 14 against the machine stator 2.

[0041] In the example of Figure 2, the machine stator 2 has an axial recess 26 concentric with the centering openings 17, into which the housing lower part 14 is axially inserted. The housing lower part 14 can have a flange 27 on the radial outside, on which the through-openings 18 are formed. The housing lower part 14 can further have a pot-shaped housing body 28 which has a housing base 29 and a circumferential housing wall 30. The flange 27 of the housing lower part 14 is formed at an end of the housing wall 30 remote from the housing base 29. An axial gap 31 is formed within the recess 26 axially between the housing base 29 and the machine stator 2. Furthermore, an annular circumferential radial gap 32 is formed within the recess 26 radially between the housing wall 30 and the machine stator 2.

[0042] In the example shown here, the upper housing part 15 also has a flange 33 on the radial outside, on which the sleeves 19 are formed. Furthermore, the upper housing part 15 in the example also has a pot-shaped housing body 34, which has a housing base 35 and a circumferential housing wall 36, wherein the flange 33 of the upper housing part 15 is formed at an end of the housing wall 36 remote from the housing base 35.

[0043] The flange 27 of the lower housing part 14 and / or the flange 33 of the upper housing part 15 can be configured to extend circumferentially in the circumferential direction U. An embodiment shown in Figure 3 is also possible, in which the flange 33 of the upper housing part 15 can be segmented in the circumferential direction U and formed only along several circumferential sections, namely only where a sleeve 19 is provided. In a corresponding manner, the flange 27 of the lower housing part 14 can now also be segmented and formed only along those circumferential sections in which a through-opening 18 is provided.

[0044] The respective sleeve 19 contains a sleeve through-opening 37, which axially penetrates the sleeve 19 and the upper housing part 15 in the area of ​​the sleeve 19. The screw 20 is inserted with its shaft 22 through the sleeve through-opening 37.

[0045] The lower housing part 14 and the upper housing part 15 can be manufactured as injection-molded plastic parts. In particular, the sleeves 19 can be molded integrally and from the same material on the upper housing part 15.

[0046] In the preferred example shown here, the centering openings 17 are cylindrical and have a circular inner cross-section 40. The through-openings 18 are cylindrical and have a circular inner cross-section 38. The sleeves 19 are hollow-cylindrical and have a circular inner cross-section, which forms the likewise cylindrical sleeve through-opening 37, and a circular outer cross-section 39.

[0047] For particularly good positioning between the upper housing part 15 and the lower housing part 14, the inner cross section 38 of the respective through-opening 18 can have the same nominal diameter as the outer cross section 39 of the respective sleeve 19. For optimal positioning of the transformer housing 13 on the machine stator 2, the inner cross section 40 of the respective centering opening 17 can also have the same nominal diameter as the outer cross section 39 of the respective sleeve 19. For simplified insertion of the sleeve 19 into the through-opening 18 and into the centering opening 17, the sleeve 19 has a chamfer 41 at its free-standing end.

[0048] A ferrite core 42 can be arranged fixed to the stator in the transformer housing 13 and is configured to surround the primary coil 10 and the secondary coil 11. For this purpose, the ferrite core 42 can be axially divided such that it has an upper core part 43 arranged in the upper housing part 15 and a lower core part 44 arranged in the lower housing part 14. According to Figure 2, the upper core part 43 can be glued into the upper housing part 15. Likewise, the lower core part 44 can be glued into the lower housing part 14. A corresponding bond is designated by 45. The bond 45 can be made using a synthetic resin.

[0049] According to Figure 1, the rotor shaft 5 can penetrate concentrically into the transformer housing 13 and support the transformer rotor 9 inside the transformer housing 13, namely in the housing interior 16. The transformer rotor 9 can have a coil carrier 46, which is attached to the rotor shaft 5 in a rotationally fixed and axially fixed manner and on which the secondary coil 11 is attached or formed. In the example of Figure 1, the rectifier 12 is also arranged or formed on the coil carrier 46.

[0050] Figure 1 also shows a bearing 47 for rotatably supporting the rotor shaft 5 on the machine stator 2.

[0051] *****

Claims

Claims 1. Inductively electrically excited synchronous machine (1), - with a machine stator (2), - with a machine rotor (3) which is mounted on the machine stator (2) so as to be rotatable about a rotation axis (4) and which has a rotor winding (6), - with a rotary transformer (7) for supplying the rotor winding (6) with electrical energy, which has a stator-fixed transformer stator (8) with a primary coil (10) and a rotor-fixed transformer rotor (9) with a secondary coil (11), - with a rotor-fixed rectifier (12), via which the secondary coil (11) is electrically coupled to the rotor winding (6), - wherein the transformer stator (8) has a transformer housing (13) which has a lower housing part (14) and an upper housing part (15) axially adjacent thereto, - wherein the housing lower part (14) and the housing upper part (15) delimit a housing interior (16) in which the transformer rotor (9) is arranged rotatably about the rotation axis (4) and in which the primary coil (10) is arranged fixed to the stator, characterized in that - that the machine stator (2) has several axial centering openings (17) distributed in the circumferential direction (U), - that the housing lower part (14) has a plurality of axial through openings (18) distributed in the circumferential direction (U), - that the upper housing part (15) has a plurality of axially projecting sleeves (19) distributed in the circumferential direction (U), - that the centering openings (17), the through-openings (18) and the sleeves (19) are coordinated with one another in such a way that in a predetermined rotational position between the machine stator (2), the lower housing part (14) and the upper housing part (15), the sleeves (19) each penetrate axially through a through opening (18) into a centering opening (17).

2. Synchronous machine (1) according to claim 1, characterized in that - that the centering openings (17), the through-openings (18) and the sleeves (19) are coordinated with one another in such a way that the sleeves (19) only penetrate axially into a centering opening (17) in a single predetermined rotational position between the machine stator (2), the lower housing part (14) and the upper housing part (15) through a through-opening (18).

3. Synchronous machine (1) according to claim 1 or 2, characterized in that - that screws (20) are screwed through the sleeves (19) into the machine stator (2).

4. Synchronous machine (1) according to claim 3, characterized in that - that the machine stator (2) has an axial screw opening (21) within each of the centering openings (17), which is arranged concentrically to the respective centering opening (17), - that the screws (20) are each screwed into such a screw opening (21).

5. Synchronous machine (1) according to claim 3 or 4, characterized in that - that the respective screw (20) has a screw head (25) which presses the upper housing part (15) against the lower housing part (14) and the lower housing part (14) against the machine stator (2).

6. Synchronous machine (1) according to one of the preceding claims, characterized in that - that the machine stator (2) has an axial recess (26) concentric with the centering openings (17), into which the housing lower part (14) is axially inserted.

7. Synchronous machine (1) according to one of the preceding claims, characterized in that - that the lower housing part (14) has a flange (27) on which the through openings (18) are formed.

8. Synchronous machine (1) according to claims 6 and 7, characterized in that - that the housing lower part (14) has a pot-shaped housing body (28) which has a housing base (29) and a circumferential housing wall (30), - that the flange (27) of the housing lower part (14) is formed on the housing wall (30) at an end remote from the housing base (29), - that the recess (26) and the housing lower part (14) are matched to one another in such a way that an axial gap (31) is formed axially between the housing base (29) and the machine stator (2) within the recess (26) and an annular circumferential radial gap (32) is formed radially between the housing wall (30) and the machine stator (2).

9. Synchronous machine (1) according to one of the preceding claims, characterized in that - that the upper housing part (15) has a flange (33) on which the sleeves (19) are formed, and / or - that the housing upper part (15) has a pot-shaped housing body (34) which has a housing base (35) and a circumferential housing wall (36), wherein the flange (33) of the housing upper part (15) can be formed on the housing wall (36) at an end remote from the housing base (35).

10. Synchronous machine (1) according to one of the preceding claims, characterized in that - that the sleeves (19) are formed of the same material and / or integrally on the upper housing part (15).

11. Synchronous machine (1) according to one of the preceding claims, characterized in that - that an inner cross-section (38) of the respective through-opening (18) and an outer cross-section (39) of the respective sleeve (19) have the same nominal diameter, and / or - that an inner cross-section (40) of the respective centering opening (17) and an outer cross-section (39) of the respective sleeve (19) have the same nominal diameter.

12. Synchronous machine (1) according to one of the preceding claims, characterized in that - that a ferrite core (42) is arranged in the transformer housing (13) in a stator-fixed manner and surrounds the primary coil (10) and the secondary coil (11).

13. Synchronous machine (1) according to claim 12, characterized in that - that the ferrite core (42) is divided and has an upper core part (43) arranged in the upper housing part (15) and a lower core part (44) arranged in the lower housing part (14).

14. Synchronous machine (1) according to one of the preceding claims, characterized in that - that a rotor shaft (5) of the machine rotor (3) penetrates concentrically into the transformer housing (13) and carries the transformer rotor (9) inside the transformer housing (13).

15. Synchronous machine (1) according to one of the preceding claims, characterized in that - that the transformer rotor (9) has a coil carrier (46) which is fastened to a rotor shaft (5) of the machine rotor (3) and to which the secondary coil (11) is fastened and / or formed. *****

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