Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
  • H02K7/003—Couplings; Details of shafts
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
  • H02K11/04—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection for rectification
  • H02K11/042—Rectifiers associated with rotating parts, e.g. rotor cores or rotary shafts
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F38/00—Adaptations of transformers or inductances for specific applications or functions
  • H01F38/18—Rotary transformers
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K1/00—Details of the magnetic circuit
  • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
  • H02K1/22—Rotating parts of the magnetic circuit
  • H02K1/32—Rotating parts of the magnetic circuit with channels or ducts for flow of cooling medium
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K9/00—Arrangements for cooling or ventilating
  • H02K9/19—Arrangements for cooling or ventilating for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil

Definitions

• the invention relates to a rotor for an externally excited synchronous machine according to the preamble of claim 1.
• the invention also relates to an externally excited synchronous machine or a traction motor for a motor vehicle or a servomotor with such a rotor.
• So-called externally excited synchronous machines require an electrical direct current in their rotor to generate the magnetic rotor field. This process is called "rotor excitation".
• the electrical rotor current is transferred to the rotating rotor with the help of so-called carbon brush slip ring contacts.
• the disadvantage of this is that the carbon brushes wear out due to wear, especially at high speeds, and can produce undesirable electrically conductive carbon dust.
• rotary transformers which are located outside of a rotor shaft, are used for contactless energy transmission in the rotor.
• the magnetic field of the stator winding of the electrically separately excited synchronous machine can impair the function of the rotary transformer.
• the present invention is therefore concerned with the problem of specifying an improved or at least an alternative embodiment for a rotor of the generic type, which in particular overcomes the disadvantages known from the prior art.
• the present invention is based on the general idea of reducing magnetic interference effects and mechanical forces acting on a rotary transformer of a rotor for an electrically separately excited synchronous machine or a traction motor for a motor vehicle or a servomotor by having a part of the rotary transformer connected non-rotatably to the rotor is arranged for energy transmission to the rotor within a rotor shaft of the rotor. Thanks to this compact design, which is radially relatively close to an axis of rotation of the rotor, the centrifugal forces that occur during operation, i.e. when the rotor rotates, can also be reduced, as can magnetic fields acting on the rotary transformer from outside, i.e.
• the rotor according to the invention for the separately excited synchronous machine has the aforementioned hollow rotor shaft, on the outer surface of which the rotor windings are arranged. Also provided is a rectifier electrically connected to the rotor winding. According to the invention, the rectifier and a secondary coil of a rotary transformer rotor are now arranged inside the hollow rotor shaft.
• the aforementioned effects can be achieved, namely a significant improvement in electromagnetic compatibility through optimized shielding through the hollow rotor shaft and an improvement in mechanical stability through the arrangement of both the rectifier and the secondary coil on very small diameters.
• the rotor can also be used for a traction motor for a motor vehicle or a servomotor.
• the rectifier and the secondary coil expediently form a prefabricated assembly.
• it is of great advantage if they form a coherent, prefabricated or prefabricated assembly that can be mounted as a common component in the hollow shaft. In particular, this can significantly simplify electrical contacting of the secondary coil with the rectifier, for example.
• the secondary coil and the rectifier are expediently glued, welded, soldered, screwed, pressed, clipped and/or cast together, for example embedded in a plastic matrix. Even this non-exhaustive list gives an idea of the diverse possibilities of a Coupling of the rectifier with the secondary coil are possible, in particular casting the secondary coil and the rectifier in a plastic jacket at the same time causes electrical insulation of the components to the outside. Gluing is also a connection process that is comparatively simple and quick to carry out.
• the secondary coil and the rectifier can also be clipped or screwed together, which means that if the rectifier is defective, for example, the assembly can be removed from the hollow rotor shaft Rectifier swapped out, replaced with a new and working rectifier and the new rectifier and secondary coil assembly can then be placed back into the rotor's hollow rotor shaft.
• the assembly has fluid-permeable openings, so that a coolant can flow in the hollow rotor shaft.
• a coolant can flow in the hollow rotor shaft.
• the secondary coil is arranged in a ring shape around an axis of rotation of the hollow rotor shaft.
• This ring-shaped design or arrangement of the secondary coil enables an optimized intermeshing assembly with a transformer core, which has a primary coil, of a rotary transformer stator of the rotary transformer.
• the present invention is also based on the general idea of a separately excited synchronous machine or a traction motor for a motor vehicle or to equip a servomotor with a rotor that can be electrically energized in accordance with the previous paragraphs and a rotary transformer stator that is arranged in the hollow rotor shaft, thereby transferring the advantages that can be achieved with regard to the rotor to the synchronous machine.
• the advantages are a compact design, an improvement in electromagnetic compatibility by arranging the rotary transformer inside the hollow rotor shaft, as a result of which the rotor shaft itself serves as magnetic shielding.
• a significant improvement in the mechanical stability of the rotary transformer can be achieved, since both the rectifier and the secondary coil of the rotary transformer rotor can be placed on a very small pitch circle diameter and thus experience low centrifugal forces during operation.
• the rotary transformer stator has a primary coil and a transformer core made of a magnetic core material, for example ferrite.
• the rotary transformer stator has the primary coil that interacts with the secondary coil of the rotary transformer rotor and, when the synchronous machine is installed, is also inside the hollow rotor shaft and is therefore both space-optimized and optimized with regard to the effects of parasitic influences such as magnetic interference fields and forces such as For example, centrifugal forces protected.
• the transformer core expediently has an inner ring, an outer ring and a web connecting the inner ring and the outer ring in each case at one end face, the primary coil being arranged on the inner ring and an annular recess being provided between the inner ring and the outer ring.
• the secondary coil of the rotary transformer engages in this annular recess during operation, as a result of which a space-optimized solution can be created.
• this also allows the rotary transformer to be assembled extremely simple by simply plugging the secondary coil into the recess of the transformer core.
• the primary coil could also be arranged on the outer ring and an annular recess could be provided between the inner ring and the outer ring, into which the secondary coil of the rotary transformer engages during operation.
• the rotary transformer stator is arranged on a bearing journal for mounting the rotor.
• the rotary transformer stator is also arranged at a different point, for example on a housing of the separately excited electrical synchronous machine, with the bearing journal also being able to provide a bearing point close to the rotary transformer, which between the secondary coil and the recess in the transformer core existing annular gaps reliably guaranteed. In this way, a long-term smooth rotary movement of the rotor can be guaranteed.
• the bearing journal expediently has a cooling channel for the passage of coolant.
• a cooling channel can, for example, run through the bearing journal in the axial direction and in particular also coaxially, as a result of which the entire rotary transformer arranged inside the hollow rotor shaft can be cooled via the coolant. In this way, in particular, a higher output of the externally excited synchronous machine can be achieved through active cooling of the rotor.
• FIG. 2 shows a sectional view through a rotor according to the invention with a rotary transformer rotor arranged inside a hollow rotor shaft,
• FIG. 3 shows a sectional view through a bearing journal for mounting the stator of the rotary transformer (primary coil) in a separately excited synchronous machine
• FIG. 4 shows a sectional view through the separately excited synchronous machine according to the invention.
• a rotor T for a separately excited synchronous machine 2 ′ has a rotor winding 3 ′, which is arranged on a hollow rotor shaft 4 ′.
• the rotor T also has a balancing ring 5' and a rectifier 6', with any imbalances that may occur being able to be compensated for via the balancing ring 5'.
• the rectifier 6' in turn directs the electric current transmitted by a rotary transformer 8' to a secondary coil 7' which is non-rotatably connected to the hollow rotor shaft 4'. This is from the rectifier 6 'in direct current converted and forwarded to the rotor winding 3 ', whereby a magnetic field can be generated there.
• the secondary coil 7' is part of a rotary transformer rotor 9' which, together with a stationary rotary transformer stator 10', forms the rotary transformer 8'.
• the rotary transformer stator 10' has a transformer core 1T and a primary coil 12'.
• the transformer core 1T is made from a magnetic core material, for example a ferrite.
• the rotor T is mounted via bearings 13'.
• a winding overhang 14' is provided on each end face of the rotor winding 3', via which electrical contact is made with the rectifier s'.
• the disadvantage of the rotor T known from the prior art according to Fig. 1 is that the secondary coil 7' has a comparatively large diameter outside the rotor shaft 4', which on the one hand requires more installation space and on the other hand comparatively high pressure on the secondary coil 7 during operation 'of the rotary transformer rotor 9' acting forces occur in the form of centrifugal forces.
• a stator field of the electrical machine or synchronous machine 2' can influence the function of the rotary transformer 8' through parasitic effects, such as magnetic fields, which can also have a disadvantageous effect.
• a hollow rotor shaft 4 with a rotor winding 3 arranged thereon is also provided.
• a rectifier 6 is electrically connected.
• Another major advantage of the arrangement of the rotary transformer rotor 9 within the hollow rotor shaft 4 is the comparatively small diameter and thus the distance between the secondary coil 7 and a rotation axis 16, which also reduces the centrifugal forces acting on the secondary coil 7 during operation of the synchronous machine 2 and thereby a load acting on the secondary coil 7 or also the rectifier 6 can be minimized, which has a positive effect on the service life of such a synchronous machine 2 .
• the rectifier 6 and the secondary coil 7 can also form a prefabricated assembly 17 which is fixed in the hollow rotor shaft 4 as a whole.
• the secondary coil 7 and the rectifier 6 can be glued, welded, soldered, screwed, pressed, clipped and/or cast together in a plastic matrix to produce the prefabricated assembly 17 . If you want an embodiment that is easy to repair, clipping or screwing the rectifier 6 to the secondary coil 7 is a good idea, which means that if the rectifier 6 is defective, it can be replaced with a new one and the secondary coil 7 can continue to be used.
• a coating in the form of a protective layer can be created which not only protects the secondary coil 7 and electronic components such as diodes of the rectifier 6 but also electrically insulates them from the environment.
• the assembly 17 has a fluid-permeable opening 18, so that a coolant flowing in the hollow rotor shaft 4 can also penetrate the assembly 17.
• the assembly 17 is preferably designed to be streamlined and has, for example, curves. This also allows pressure losses to be minimized.
• the secondary coil 7 is arranged in a ring around the axis of rotation 16 of the hollow rotor shaft 4 . Due to the ring-shaped arrangement of the secondary coil 7 around the axis of rotation 16, a ring-cylindrical design can be selected, which significantly simplifies subsequent assembly.
• the transformer core 11 has an inner ring 19 , an outer ring 20 and a web 21 connecting the inner ring 19 and the outer ring 20 on an end face, with the primary coil 12 being arranged in a depression 22 on the inner ring 19 .
• annular recess 23 is arranged between the inner ring 19 and the outer ring 20, into which the annular secondary coil 7 of the rotary transformer Ro- Tors 9 engages or immerses in the assembled state. In this way, a particularly space-optimized arrangement of the entire rotary transformer 8 within the hollow rotor shaft 4 can be achieved.
• the rotary transformer stator 10 is arranged on a bearing journal 24 which carries a bearing 13 for supporting the rotor 1.
• the bearing journal 24 in turn has at least one cooling duct 25 for conducting coolant, wherein the cooling duct 25 can run in the axial direction and transversely thereto, and in particular a cooling duct 25a running transversely thereto can be used to cool the bearings 13 .
• the rotary transformer stator 11 is arranged in a rotationally fixed manner on the bearing journal 24, with the bearing journal 24 being, for example, part of a bearing plate of the synchronous machine 2 or being placed on it.
• the secondary coil 7 can also have a coating or, for example, be embedded in a plastic sheath.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Synchronous Machinery (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (5)

Cited By (3)

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Citations (3)

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• 2021
  • 2021-10-25 DE DE102021212012.1A patent/DE102021212012B3/de active Active
• 2022
  • 2022-09-06 JP JP2024523860A patent/JP2024537447A/ja active Pending
  • 2022-09-06 CN CN202280071410.8A patent/CN118160201A/zh active Pending
  • 2022-09-06 US US18/704,447 patent/US20240421669A1/en active Pending
  • 2022-09-06 WO PCT/EP2022/074675 patent/WO2023072461A1/de not_active Ceased

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