Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K3/00—Details of windings
  • H02K3/46—Fastening of windings on the stator or rotor structure
  • H02K3/50—Fastening of winding heads, equalising connectors, or connections thereto
  • H02K3/51—Fastening of winding heads, equalising connectors, or connections thereto applicable to rotors only
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K19/00—Synchronous motors or generators
  • H02K19/02—Synchronous motors
  • H02K19/10—Synchronous motors for multi-phase current
  • H02K19/12—Synchronous motors for multi-phase current characterised by the arrangement of exciting windings, e.g. for self-excitation, compounding or pole-changing
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F27/00—Details of transformers or inductances, in general
  • H01F27/28—Coils; Windings; Conductive connections
  • H01F27/32—Insulating of coils, windings, or parts thereof
  • H01F27/323—Insulation between winding turns, between winding layers
• • 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
  • 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
  • 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
  • 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
  • H02K7/04—Balancing means
• • 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 a separately excited synchronous machine according to the preamble of claim 1.
• the invention also relates to an electrically separately excited synchronous machine with such a rotor.
• So-called externally excited electrical synchronous machines require an electrical direct current in their rotor to generate the magnetic rotor field. This process is called "rotor excitation".
• the electric rotary transformer rotor current is transferred to the rotating rotor using 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.
• the functional principle of said inductive energy transmission is based on an electrical transformer, with the primary coil of the transformer being arranged on the stator of the synchronous machine and the secondary coil on the rotating rotor. Since an electrical AC voltage is always initially generated in the secondary coil during inductive energy transmission, it is necessary to electrically rectify this AC voltage using a suitable rectifier circuit, which can also be arranged on the rotor, i.e. to convert it into an electrical DC voltage. In the case of synchronous machines known from the prior art, it is also known to arrange a rotary transformer outside of the synchronous machine and thus to make it both easily accessible and easy to manufacture.
• the present invention is therefore concerned with the problem of specifying an improved or at least an alternative embodiment for a rotor for a separately excited synchronous machine of the generic type, in which the disadvantages known when the rotary transformer is arranged in the synchronous machine can be overcome.
• the present invention is based on the general idea of installing a rotary transformer in a separately excited synchronous machine and thereby arranging a rotary transformer rotor on a balancing ring of the rotor, while a rotary transformer stator is arranged on the synchronous machine, for example on a housing of the same.
• the rotor according to the invention for such a separately excited synchronous machine has a rotor shaft with rotor windings arranged thereon and a balancing ring to compensate for any imbalances that may be present.
• a rectifier electrically connected to the rotor windings, which converts AC voltage from a rotary transformer to DC voltage.
• a rotary transformer rotor of the rotary transformer is now arranged on the balancing ring with a secondary coil which projects away from the rotor windings in the axial direction of the balancing ring.
• the balancing ring is thus part of the (synchronous machine) rotor, with a rotating secondary coil, ie the rotary transformer rotor, being part of the rotary transformer and being integrated into the rotor.
• Such a rotor offers the great advantage that the rotary transformer rotor arranged on the balancing ring can be balanced comparatively easily with the secondary coil together with the rotor and at the same time the rotary transformer can be easily installed by plugging the secondary coil arranged on the rotor into a rotary transformer arranged on the synchronous machine -Stator is enabled.
• the rotary transformer stator which usually has a transformer core, is arranged in a stationary manner on the synchronous machine, in particular on a housing thereof, and therefore does not rotate, which means that high rotor speeds are possible.
• the balancing ring, the rectifier and the secondary coil form a prefabricated assembly.
• the balancing ring together with the rectifier and the secondary coil as a prefabricated or prefabricated assembly, a final assembly process of the synchronous machine can be significantly streamlined, since the prefabrication of the assembly can be outsourced to a separate assembly process.
• This prefabrication can thus, for example, run parallel to the prefabrication of the rotor, as a result of which the overall rotor production can be streamlined in terms of time.
• Certain quality processes can also be run through in advance for the prefabricated assembly, as a result of which quality assurance can be improved.
• the secondary coil, the rectifier and the balancing ring are expediently glued, welded, soldered, screwed, pressed, clipped and/or cast together, in particular cast in a common plastic matrix. Even this non-exhaustive list gives an idea of the diverse possibilities of connection technologies that are available. In particular, casting them together in a plastic material not only enables easy handling, but also protects the individual components, in particular the rectifier and the secondary coil, from dirt, for example.
• the secondary coil has a coating and is electrically insulated from the environment by this coating, for example a plastic jacket.
• a protected arrangement of the secondary coil below the coating is also possible as a result and, in addition, a comparatively narrow gap dimension between the rotary transformer rotor and the rotary transformer stator. Such a narrow gap allows the rotary transformer to be operated particularly efficiently.
• the secondary coil is arranged in a ring shape around an axis of rotation of the hollow rotor shaft.
• a ring-shaped design of the secondary coil around an axis of rotation of the hollow rotor shaft makes it possible to design the secondary coil as a hollow cylinder, for example, while a transformer core of a rotary transformer stator that interacts with it can also be ring-shaped with an axial open gap in which the secondary coil of the rotary transformer -Rotor can be inserted during assembly of the synchronous machine.
• the ring-shaped secondary coil of the rotary transformer rotor protrudes in the axial direction from the balancing ring, for example, and can therefore be pushed comparatively easily into the opposite recess of the transformer core, which is open in the axial direction, during assembly of the electrically separately excited synchronous machine.
• the rectifier is arranged radially inside the balancing ring and/or is supported on a radial step of the balancing ring or on an inner lateral surface of the balancing ring.
• the end windings of the rotor windings are arranged on the end faces thereof, with the rectifier and the balancing ring forming a housing surrounding the end windings and at the same time electronic components, such as diodes, of the rectifier being arranged in a housing interior of this housing.
• the rotor shaft is hollow and has a cooling duct for the passage of coolant, which is connected to the inside of the housing and thus also to the electronic components of the rectifier and the end windings of the rotor windings so that by conducting coolant through the cooling duct both the End windings of the rotor windings and the electronic component of the rectifier can be cooled.
• the hollow rotor shaft not only enables cooling, but also saves resources and weight.
• the present invention is also based on the general idea of equipping an externally excited synchronous machine with a rotor that can be electrically energized as described in the previous paragraphs and thereby achieving a comparatively simply constructed synchronous machine in which not only a comparatively simple balancing process of the rotor is possible, but also a reduced space requirement due to of installing the rotary transformer in the synchronous machine. Since the comparatively heavy transformer core with the primary coil in the synchronous machine according to the invention at the synchronous machine, for example, is arranged on a housing of the same or a bearing, this does not rotate, so that comparatively high speeds of the synchronous machine can be achieved.
• the transformer core has a magnetic core material, preferably made of ferrite.
• the synchronous machine can be designed as a traction motor of a motor vehicle.
• the transformer core expediently has an inner ring, an outer ring and a stator web connecting the inner ring and the outer ring at one end each, with the primary coil of the rotary transformer stator being arranged in a recess on the inner ring of the transformer core and with an annular recess between the inner ring and the outer ring and a recess open in the axial direction is provided.
• FIG. 1 shows a longitudinal section through a rotor of an electrically separately excited synchronous machine according to the prior art
• FIG. 2 shows a sectional view through a synchronous machine according to the invention during assembly of a rotor
• Fig. 3 shows a representation as in Fig. 2, but in the assembled state
• FIG. 4 shows a representation as in FIG. 3, but with a different embodiment.
• a rotor T of an electrically separately excited synchronous machine 2 ′ which is otherwise not shown in detail, has rotor windings 3 ′, which are arranged on a hollow rotor shaft 4 ′. Also provided is a balancing ring 5' to compensate for any imbalances that may occur.
• a rectifier 6' is also provided, which in this case is arranged for rotation on an outer lateral surface of the hollow rotor shaft 4'. The rectifier 6' is electrically connected to the rotor windings 3' on the one hand and to a rotary transformer 7' on the other hand.
• the rotary transformer 7' in turn has a rotary transformer rotor 8' with a secondary coil 9' and a rotary transformer stator 10' with a primary coil 11'.
• the rotary transformer stator 10' also has a transformer core 12' made of a magnetic core material, in particular a ferrite.
• the magnetic core material or the transformer core 12' is arranged in a stationary manner.
• the end windings 13' of the rotor windings 3' are also located at the end faces of the rotor windings 3'.
• FIGS. 2 to 4 A rotor 1 according to the invention and a separately excited synchronous machine 2 according to the invention are therefore described in the following FIGS. 2 to 4, which no longer have the disadvantages known from the prior art.
• the same reference numerals are used for individual components in FIGS. 2 to 4 as in FIG. 1, but without an apostrophe, in order to clearly distinguish between a rotor T according to the prior art and a rotor 1 according to the invention or a synchronous machine 2 according to the invention make possible.
• the rotor 1 according to the invention shown in FIGS. 2 to 4 for a separately excited synchronous machine 2 also has a hollow rotor shaft 4 on which Rotor windings 3 are arranged. Furthermore, a balancing device 5 is also provided for compensating for any imbalances of the rotor 1 that may be present.
• a rectifier 6 is provided, which is connected to both the rotary transformer 7 and the secondary coil 9 of the rotary transformer rotor 8 of the rotary transformer 7 , as well as with the rotor windings 3 or their end windings 13.
• the previously described rotary transformer ator rotor 8 of the rotary transformer 7 is now on the balancing 5 with a secondary coil 9 which projects in the axial direction 14 from the balancing 5 .
• the balancing device 5, the rectifier 6 and also the secondary coil 9 can form a prefabricated or prefabricated subassembly which can be mounted on the rotor 1 in the prefabricated state.
• the secondary coil 9, the rectifier 6 and the balancing device 5 can, for example, be glued, soldered, welded, screwed, pressed, clipped and/or cast together, in particular cast into a plastic matrix.
• the last variant, in particular, enables the previously mentioned components 5, 6 and 9 to be arranged protected under a plastic film or casing, and this assembly group consisting of at least the components 5, 6 and 9 to be handled easily.
• the great advantage of such an assembly is that it can be prefabricated separately from the rotor, for example in parallel, which means that the assembly and manufacturing process of the rotor 1 according to the invention can be streamlined overall, i.e. shortened, if the secondary coil 9 is encased in a plastic matrix it is coated with plastic and is therefore electrically insulated from the environment.
• the synchronous machine 2 according to the invention has the aforementioned rotary transformer stator 10 (see FIGS. 2 to 4) with a primary coil 11 and a transformer core 12, which is usually made of a magnetic core material, preferably a ferrite.
• the transformer core 12 is arranged in a stationary manner, ie it does not rotate during operation of the synchronous machine 2, as a result of which the rotor 1 of the synchronous machine 2 according to the invention can achieve significantly higher speeds.
• the transformer core 12 has an inner ring 15, an outer ring 16 and a stator bar 17 connecting the inner ring 15 and the outer ring 16 on one end side, with the primary coil 11 in a recess 18 on the inner ring 15 is arranged (see. Fig. 2 and 3).
• an arrangement of the primary coil 11 in a recess 18' of the outer ring 16 is also conceivable, as shown in FIG.
• the synchronous machine 2 can be designed as a traction motor of a motor vehicle.
• the primary coil 11 and the secondary coil 9 lie directly opposite one another, while they are still separated by a carrier web 27 according to FIG. Since a magnetic flux closes via the ferrite core (transformer core 12), the carrier web 27 does not interfere, provided that it is made of a non-magnetic and electrically non-conductive material.
• the carrier web 27 is able to support the secondary coil 9 since high centrifugal forces can act on it during operation. Due to the comparatively small distance between the rotating secondary coil 9 in FIG. 4 and the axis of rotation 30, only smaller centrifugal forces act on the secondary coil 9 in the embodiment according to FIG is reachable.
• annular recess 19 is arranged between the inner ring 15 and the outer ring 16, in which the annular secondary coil 9 of the rotary transformer rotor 8 engages.
• the secondary coil 9 protruding in the axial direction 14 from the rotor windings 3 or the balancing ring 5 can be pushed into the recess 19 of the transformer core 12 in the insertion direction 20 during the assembly process, as shown in FIG. 2, and the rotary transformer 7 can thereby be produced .
• the transformer core 12 or the rotary transformer stator 10 can be arranged, for example, on a housing 21 of the synchronous machine 2 but also on a bearing flange 28 .
• the embodiment according to the invention also has the advantage that the rotary transformer 7 has (almost) no rotating ferrite material despite the radial arrangement/construction, and the rotating secondary coil 9 contains (almost) no ferrite material.
• the figures only indicate a piece of (rotating) ferrite core in the area of the secondary coil 9, which serves to reduce an air gap and thereby reduce the leakage inductance and increase the efficiency of the rotary transformer 7.
• the ferrite core is also (primarily) designed as a fixed, stationary ferrite core, which results in a minimization of the rotating ferrite material. Due to the poor mechanical properties (brittle, low speed stability) of the ferrite material, higher speeds can be achieved with this structure than with a structure with a rotating ferrite core/ferrite material.
• the rectifier 6 is arranged radially inside the balancing ring 5 and is supported on this or on an inner lateral surface 22 of the balancing ring 5 (cf. FIGS. 2 and 3). .
• the rectifier 6 is supported on a radial step 23 of the balancing ring 5, as shown in FIG. 4, whereby the rectifier 6 can be held in a form-fitting manner both in the radial direction and in the axial direction 14.
• the rotor 1 or its rotor windings 3 also have end windings 13, with the balancing ring 5 encompassing the end windings 13 on an outer lateral surface and on an axial end face, as is shown in FIGS. 2 to 4.
• the rectifier 6 and the balancing ring 5 form a housing surrounding the end windings 13 (see FIG. 4), with electronic components 24 of the rectifier 6, such as diodes, being arranged in a housing interior 25. This allows the electronic components 24 to be arranged in a protected manner.
• the rotor shaft 4 can also be hollow and have a cooling duct 26 for conducting coolant, with this cooling duct 26 being connected to the housing interior 25 in a communicating manner.
• the rectifier 6 with its printed circuit board is preferably connected in a fluid-tight manner to an outer lateral surface of the rotor shaft 4, as a result of which the housing interior 25 is only accessible via the cooling duct 26.
• the assembly consisting of balancing ring 5, secondary coil 7 and rectifier s is tightly connected on the one hand to the outer lateral surface of rotor shaft 4 and on the other hand to an end face of rotor windings 3, for example glued.
• the balancing ring 5 can also have the ring-shaped support web 27 which is formed in one piece with the balancing ring 5 and on which the secondary coil 9 is fixed with its windings. According to FIG.
• the rotor shaft 4 of the rotor 1 is mounted on the housing 21 via the bearing flange 28 and a bearing 29 arranged there.
• a stator 31 of the synchronous machine 2 Surrounding the rotor 1 is a stator 31 of the synchronous machine 2 with corresponding stator windings, as shown in FIGS.
• the rotor T of the synchronous machine 2' usually has two so-called balancing shields or balancing rings 5' at both ends, which are made of a comparatively heavy material, in particular steel, with a large diameter (relative to the axis of rotation 30' ) are arranged.
• the rotor T is picked up at the bearing seats, rotated and the imbalance that occurs at a predefined speed is determined.
• the rotor T is then balanced by means of balancing bores (removal of material) or gluing in balancing weights (addition of material).
• the rotating secondary coil 9 of the rotary transformer rotor 8 is part of the rotor 1 according to the invention or is integrated into it, both components can be balanced in a common balancing process, resulting in lower process times and costs. This is particularly useful for the reason that in the interior of the rotary transformer 7 (and thus directly on the secondary coil 9) no magnetically or electrically conductive material can be used due to shielding effects to be avoided.
• the secondary coil 9 itself has copper with a significantly higher density than the corresponding carrier material (plastic, plastic composite material, etc.), as a result of which the balancing of the rotary transformer rotor 8 is complex.
• the transformer core 12 Since the transformer core 12 is arranged in a stationary manner on the synchronous machine 2, for example on its housing 21, the rotor 1 can also reach high speeds.

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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)

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Cited By (1)

Families Citing this family (8)

Citations (3)

• 2021
  • 2021-10-27 DE DE102021212152.7A patent/DE102021212152A1/de active Pending
• 2022
  • 2022-09-06 JP JP2024523858A patent/JP2024541885A/ja active Pending
  • 2022-09-06 CN CN202280072252.8A patent/CN118160196A/zh active Pending
  • 2022-09-06 US US18/704,914 patent/US20250015693A1/en active Pending
  • 2022-09-06 WO PCT/EP2022/074679 patent/WO2023072463A1/de not_active Ceased

Patent Citations (3)

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