Energy transmission system for contactlessly transmitting electric energy into an excitation winding of a rotor

Abstract

The invention relates to an energy transmission system, in particular a rotary transformer, for contactlessly transmitting electric energy into an excitation winding (6) of a rotor (5) of an electric machine (1), comprising a static primary unit (11) and a secondary unit (20) which can rotate about a transformer axis (21). The primary unit (11) has a primary winding (12) and a primary core (13), and the primary winding (12) is arranged, in the radial direction with respect to the transformer axis (21), between a circumferential section (13u) of the primary core (13) and a primary winding support (14), wherein the primary winding support (14) has a support inner circumference (14u) which faces away from the primary winding (12) and which surrounds an installation space for the secondary unit (20) and forms a first assembly opening (16) for axial insertion of the secondary unit (20).

Description

[0001] Description

[0002] title

[0003] Energy transfer system for the contactless transmission of electrical energy into a field winding of a rotor

[0004] State of the art

[0005] The invention is based on an energy transmission system for the contactless transmission of electrical energy into an excitation winding of a rotor according to the preamble of the main claim.

[0006] An energy transmission system for the contactless transmission of electrical energy into an excitation winding of a rotor is already known from CN217061745 U, which comprises a static primary unit and a secondary unit rotatable about a transmission axis, wherein the primary unit has a primary winding and a primary core designed as a ferrite core. The secondary unit is designed as an external rotor.

[0007] Advantages of the invention

[0008] The energy transmission system according to the invention with the characterizing features of the main claim has the advantage that a very compact primary unit is formed, which requires only a small installation space and allows an axial mounting of the secondary unit

[0009] This is achieved according to the invention in that the primary winding is arranged in the radial direction with respect to the transformer axis between a circumferential section of the primary core and a primary winding carrier, wherein the primary winding carrier has an inner carrier circumference facing away from the primary winding, which encloses an installation space for the secondary unit and forms a first assembly opening for the axial insertion of the secondary unit. Advantageous further developments and improvements of the energy transmission system specified in the main claim are possible by the measures listed in the subclaims.

[0010] It is particularly advantageous if a first core leg of the primary core extends beyond an outer circumference of the secondary unit in the radial direction relative to the transformer axis. In this way, the first core leg of the primary core extends into the radial area of ​​the secondary unit. This improves the energy transfer from the secondary side to the primary side.

[0011] Furthermore, it is advantageous if the first core leg of the primary core forms a second mounting opening for the passage of a rotary bearing for supporting the rotor of the electrical machine, wherein the second mounting opening is smaller in the radial direction with respect to the transformer axis than the first mounting opening. In this way, the secondary unit and the rotary bearing can be pre-assembled on the rotor shaft. The rotor shaft can then be mounted in the axial direction with the pre-assembled secondary unit and the pre-assembled rotary bearing. The rotary bearing is pushed through the first and second mounting openings and the secondary unit through the first mounting opening. This can simplify the installation of the energy transmission system on an electrical machine.

[0012] It is further advantageous if the primary core, the primary winding support, and the primary winding form a structural unit arranged in a transformer housing comprising a pot-shaped housing part and a cover-shaped housing part, wherein the cover-shaped housing part has a housing opening for the passage of the rotary bearing. This results in a transformer housing that allows the passage of the rotary bearing and into which the aforementioned primary parts can be easily mounted.

[0013] According to advantageous embodiments, the primary core can be formed in one piece or in several pieces.

[0014] According to an advantageous embodiment, the primary core of the primary unit can have a U-shaped or L-shaped cross-section extending around a transformer axis. It is very advantageous if the primary core of the primary unit has a U-shaped cross-sectional shape extending around the transformer axis with two core limbs extending radially relative to the transformer axis, wherein a second core limb of the primary core is shortened compared to the first core limb. The shortened second core limb forms the first mounting opening and additionally enables good flux guidance.

[0015] It is also advantageous if the primary winding carrier has a winding receptacle for receiving the primary winding, wherein the winding receptacle of the primary winding carrier is formed between two receiving shoulders of the primary winding carrier, wherein the first core leg of the primary core is supported in an axial direction with respect to the transformer axis on the primary winding carrier, in particular on one of the two receiving shoulders. In this way, the primary core is correctly positioned or centered by the primary winding carrier.

[0016] It is also advantageous if the primary winding support has a sleeve section for supporting the shortened core leg of the primary core. The sleeve section adjoins, for example, the section with the winding receptacle. In this way, the shortened leg, which is designed, for example, as a separate core part, can be aligned or centered on the primary winding support.

[0017] It is also advantageous if the secondary unit is an internal rotor having a secondary winding support with a secondary winding. The secondary winding support comprises a hub portion for passing a rotor shaft of the electric machine through and a winding receptacle for receiving the secondary winding. This results in a compact and cost-effective secondary unit.

[0018] It is also advantageous if the secondary winding of the secondary unit is an air-core coil and the secondary unit is designed without a secondary core. This increases the speed stability of the secondary unit, since soft magnetic cores, especially those made of ferrite, have only low speed stability.

[0019] The invention also relates to an electrical machine comprising a stator, a rotor rotatable about a rotor axis, having a rotor shaft and a rotor body, a bearing shield having a bearing receptacle for accommodating a pivot bearing for pivotally supporting the rotor, and an energy transmission system according to the invention. The secondary unit of the energy transmission system is connected in a rotationally fixed manner to the rotor shaft. Likewise, an inner bearing ring of the pivot bearing is connected in a rotationally fixed manner to the rotor shaft. An outer bearing ring of the pivot bearing is mounted axially movably in the bearing receptacle of the bearing shield to form a loose bearing. The transmission housing is fastened to a housing of the electrical machine, in particular to the bearing shield.

[0020] drawing

[0021] An embodiment of the invention is shown in simplified form in the drawing and explained in more detail in the following description.

[0022] Description of the embodiment

[0023] The drawing shows a section through an electrical machine with an energy transmission system according to the invention.

[0024] The electric machine 1 can be an electrically excited synchronous machine having a stator 2 with a stator winding 3 and a rotor 5 rotatable about a rotor axis 4 with an excitation winding 6. The rotor 5 comprises a rotor shaft 7 and a rotor body 5.1 mechanically coupled to the rotor shaft 7, which rotor body is, for example, a rotor core.

[0025] The energy transmission system 10 of the electrical machine 1 can also be referred to as a rotary transformer and serves for the contactless transmission of electrical energy into the excitation winding 6 of the rotor 5.

[0026] The energy transmission system 10 comprises a static primary unit 11 and a secondary unit 20 rotatable about a transmission axis 21. The primary unit 11 and the secondary unit 20 are arranged concentrically to one another, for example. The primary unit 11 has a primary winding 12 and a primary core 13. The primary core 13 is made of a soft magnetic material, in particular ferrite.

[0027] According to the invention, it is provided that the primary winding 12 is arranged in the radial direction with respect to the transformer axis 21 between a circumferential section 13u of the primary core 13 and a primary winding carrier 14, wherein the primary winding carrier 14 has an inner carrier circumference 14u facing away from the primary winding 12, which encloses an installation space for the secondary unit 20 and forms a first mounting opening 16 for the axial insertion of the secondary unit 20.

[0028] A first core leg 13.1 of the primary core 13 extends beyond an outer circumference of the secondary unit 20 in the radial direction relative to the transformer axis 21. The first core leg 13.1 of the primary core 13 forms a second mounting opening 17 for the passage of a pivot bearing 18 for supporting the rotor 5 of the electric machine. The second mounting opening 17 is designed to be smaller in the radial direction relative to the transformer axis 21, for example, than the first mounting opening 16.

[0029] The primary core 13 can be constructed in one piece or in multiple pieces.

[0030] Furthermore, the primary core 13 can have a U-shaped or L-shaped cross-sectional shape extending around the transformer axis 21. According to the exemplary embodiment, the primary core 13 has, for example, a U-shaped cross-sectional shape extending around the transformer axis 21 with two core limbs 13.1, 13.2 extending in the radial direction relative to the transformer axis 21. A second core limb 13.2 of the primary core 13 is designed to be shortened compared to the first core limb 13, for example, to form the first mounting opening 16.

[0031] The primary core 13, the primary winding support 14, and the primary winding 12 form a structural unit arranged in a transformer housing 15 comprising a pot-shaped housing part 15.1 and a cover-shaped housing part 15.2. The transformer housing 15 is attached, for example, to a housing 8 of the electrical machine 1, in particular to a bearing plate 9. The cover-shaped housing part 15.2 has a housing opening 19 for the passage of the rotary bearing 18.

[0032] The primary winding support 14 has a winding receptacle 14w for receiving the primary winding 12. The winding receptacle 14w of the primary winding support 14 is formed, for example, between two receiving shoulders 14s of the primary winding support 14. The first core leg 13.1 of the primary core 13 is supported, for example, in an axial direction relative to the transformer axis 21 on the primary winding support 14, in particular on one of the two receiving shoulders 14s.

[0033] The primary winding support 14 may also have a sleeve portion 14c for supporting the shortened core leg 13.2 of the primary core 13.

[0034] The primary winding carrier 14 is made of plastic, for example.

[0035] The secondary unit 20 has a secondary winding 22 for inductive interaction with the primary winding 12 of the primary unit 11. The secondary unit 20 is, for example, an internal rotor having a secondary winding carrier 23 with the secondary winding 22. The secondary winding carrier 23 comprises a hub section 23.1 for passing the rotor shaft 7 of the rotor 5 and a winding receptacle 23.2 for receiving the secondary winding 22. The secondary winding carrier 23 is made, for example, of plastic.

[0036] The secondary unit 20 of the energy transmission system 10 is arranged, for example, on the rotor shaft 7 of the electric machine 1 and is rotationally fixedly connected to the rotor shaft 7. The transmission axis 21 is, in particular, the rotor axis 4.

[0037] The secondary winding 22 of the secondary unit 20 is a so-called air coil. This means that the secondary unit 20 is designed without a secondary core.

[0038] The bearing plate 9 of the housing 8 has a bearing recess 9.1 for receiving the pivot bearing 18 for the pivot bearing of the rotor 5. A bearing inner ring 18i of the pivot bearing 18 is rotationally fixedly connected to the rotor shaft 7. An outer bearing ring 18a of the pivot bearing 18 is axially movable in the bearing recess 9.1 of the bearing plate 9 to form a loose bearing.

Claims

Claims 1. An energy transmission system, in particular a rotary transformer, for the contactless transmission of electrical energy into an excitation winding (6) of a rotor (5) of an electrical machine (1), comprising a static primary unit (11) and a secondary unit (20) rotatable about a transformer axis (21), wherein the primary unit (11) has a primary winding (12) and a primary core (13), characterized in that the primary winding (12) is arranged in the radial direction with respect to the transformer axis (21) between a circumferential section (13u) of the primary core (13) and a primary winding support (14), wherein the primary winding support (14) has an inner support circumference (14u) facing away from the primary winding (12), which encloses a space for the secondary unit (20) and forms a first mounting opening (16) for axially inserting the secondary unit (20).

2. Energy transfer system according to claim 1, characterized in that a first core leg (13.1) of the primary core (13) extends in the radial direction with respect to the transfer axis (21) towards the transfer axis (21) beyond an outer circumference (20a) of the secondary unit (20).

3. Energy transmission system according to claim 2, characterized in that the first core leg (13.1) of the primary core (13) forms a second mounting opening (17) for the passage of a rotary bearing (18) for supporting the rotor (5) of the electrical machine (1), wherein the second mounting opening (17) is smaller in the radial direction with respect to the transmission axis (21) than the first mounting opening (16).

4. Energy transmission system according to claim 3, characterized in that the primary core (13), the primary winding carrier (14) and the primary winding (12) form a structural unit which is arranged in a transmission housing (15) which comprises a pot-shaped housing part (15.1) and a cover-shaped housing part (15.2), wherein the cover-shaped housing part (15.2) has a housing opening (19) for the passage of the rotary bearing (18).

5. Energy transfer system according to one of the preceding claims, characterized in that the primary core (13) is designed in one piece or in several pieces.

6. Energy transmission system according to one of the preceding claims, characterized in that the primary core (13) of the primary unit (11) has a U-shaped or L-shaped cross-sectional shape extending around the transmission axis (21).

7. Energy transmission system according to claim 6, characterized in that the primary core (13) of the primary unit (11) has a U-shaped cross-sectional shape extending around the transmitter axis (21) with two core legs (13.1, 13.2) extending in the radial direction with respect to the transmitter axis (21), wherein a second core leg (13.2) of the primary core (13) is shortened compared to the first core leg (13.1) to form the first assembly opening (16).

8. Energy transfer system according to one of the preceding claims, characterized in that the primary winding carrier (14) has a winding receptacle (14w) for receiving the primary winding (12), wherein the winding receptacle (14w) of the primary winding carrier (14) is formed between two receiving shoulders (14s) of the primary winding carrier (14), wherein the first core leg (13.1) of the primary core (13) is supported in an axial direction with respect to the transformer axis (21) on the primary winding carrier (14), in particular on one of the two receiving shoulders (14s).

9. Energy transfer system according to one of claims 7 or 8, characterized in that the primary winding carrier (14) has a sleeve section (14c) for supporting the shortened second core leg (13.2) of the primary core (13).

10. Energy transmission system according to one of the preceding claims, characterized in that the secondary unit (20) is an internal rotor having a secondary winding carrier (23) with a secondary winding (22), wherein the secondary winding carrier (23) comprises a hub section (23.1) for passing through a rotor shaft (7) of the electrical machine (1) and a winding receptacle (23.2) for receiving the secondary winding (22).

11. Energy transmission system according to claim 10, characterized in that the secondary winding (22) of the secondary unit (20) is an air coil and the secondary unit (20) is designed without a secondary core.

12. Electrical machine (1) with a stator (2), with a rotor (5) rotatable about a rotor axis (4) comprising a rotor shaft (7) and a rotor body (5.1) coupled to the rotor shaft (7), with a bearing plate (9) which has a bearing receptacle (9.1) for receiving a rotary bearing (18) for the rotary mounting of the rotor (5), and with an energy transmission system (10) according to one of the preceding claims, characterized in that - the secondary unit (20) of the energy transmission system (10) with the rotor shaft (7) is connected in a rotationally fixed manner, and / or - an inner bearing ring (18i) of the rotary bearing (18) is connected to the rotor shaft (7) in a rotationally fixed manner and an outer bearing ring (18a) of the rotary bearing (18) is mounted axially movably in the bearing receptacle (9.1) of the bearing plate (9) to form a loose bearing, and / or - the transformer housing (15) is fastened to a housing (8) of the electrical machine, in particular to the bearing plate (9).

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