Stator for a permanent magnet excited electric motor / induction motor

Abstract

The invention relates to a stator for a permanently excited electric motor / induction motor, having a laminated core (1) composed of a stator core (11) and a yoke winding (2), wherein the yoke winding (2) comprises an inner winding portion (21) which is arranged radially inside the stator core (11) in at least one winding receptacle (3) and an outer winding portion (22) which is arranged radially outside the stator core (11) on an outer surface (4) of the laminated core (1), wherein a soft-magnetic shield (5) is configured around the entire circumference of the outer winding portion (22), wherein at least one non-magnetic connecting element (6) is arranged between the stator core (11) and the soft-magnetic shield (5), which non-magnetic connecting element in particular contacts the stator core (11) and the soft-magnetic shield ring (5).

Description

Technical Field

[0001] The invention relates to a stator for an electric motor / induction machine with permanent magnet excitation, comprising a laminated core formed by a stator core and a yoke winding. Background Art

[0002] Superimposed winding systems are often used for high-speed electric motors, such as synchronous or asynchronous motors with permanent magnet excitation. However, the small number of coil turns required at high speeds results in low inductance. This results in undesirable harmonic oscillations in the line current, leading to higher rotor losses. These losses are so high that countermeasures are necessary. These countermeasures are usually passive low-pass filters based on coils and capacitors. The disadvantage of these solutions is that they generally require a relatively large amount of installation space.

[0003] Another countermeasure option is to use multilevel converters, which are however significantly more complex than conventional converters and therefore also require more space. Summary of the Invention

[0004] The object of the present invention is therefore to provide a stator for an electric motor / induction machine with permanent magnet excitation, comprising a laminated core and a yoke winding, wherein operation with a pulse-controlled inverter at high speeds and with low rotor losses is possible without additional current smoothing measures.

[0005] This object is achieved by the combination of features according to claim 1 .

[0006] According to the present invention, a stator for an electric motor / induction machine with permanent magnet excitation is provided, comprising a laminated core formed of a stator core and a yoke winding. The yoke winding comprises an inner winding portion and an outer winding portion, the inner winding portion being arranged radially within the stator core in at least one winding receptacle, and the outer winding portion being arranged radially outside the stator core on the outer surface of the laminated core. Furthermore, a soft magnetic shield is formed around the entire circumference of the outer winding portion. At least one non-magnetic connecting element is arranged between the stator core and the soft magnetic shield, and in particular, the non-magnetic connecting element contacts the stator core and the soft magnetic shield ring.

[0007] Advantageously, the connection between the stator core and the stator shielding rings around which the yoke is wound is released via non-magnetically conductive connecting elements. This pairing increases the dispersion efficiency and simultaneously prevents undesirable magnetic short circuits between the two components.

[0008] In a preferred embodiment of the invention, the laminated core is constructed in one piece. In this way, the inductance and component strength of the laminated core of the stator are optimized.

[0009] Stators of this type in the technical field are usually designed such that the inner winding part and the outer winding part are connected to one another via a stator counter-wiring. This is a prerequisite for a yoke winding, wherein the stator counter-wiring is also called a yoke.

[0010] In an advantageous variant, at least one non-magnetic connecting element is formed from plastic, and one non-magnetic connecting element is arranged between adjacent winding poles of the yoke winding. Advantageously, the connecting element made of plastic meets the requirements of non-magnetic conductivity, is easy to manufacture, and is optimally adapted to the geometry of the stator core.

[0011] Furthermore, an embodiment is advantageous in which the respective non-magnetic connecting element is arranged spaced apart from the respective adjacent winding poles of the yoke winding. This achieves the desired effect of the non-magnetic connecting element with a material-saving solution.

[0012] In an alternative embodiment of the stator, the at least one non-magnetic connecting element is a cast part formed by the outer winding part. Advantageously, the cast part is formed around the entire circumference between the stator core and the shielding ring. In addition to the non-magnetic connection, this also protects the stator core from moisture, dust, contaminants, temperature influences, vibrations, and contact, and provides electrical insulation.

[0013] In another advantageous embodiment, at least one winding receptacle is designed as a slot. In this way, a tooth-type coil winding of the yoke winding can be achieved.

[0014] In one embodiment of the present invention, the yoke winding is configured with 6 poles or 6 slots. In another advantageous embodiment of the stator, the yoke winding is configured with 12 poles or 12 slots. The aforementioned variants of the yoke winding have optimal properties when the stator is used in an induction motor / permanent magnet excitation electric motor.

[0015] According to the present invention, an induction motor / permanent magnet excitation electric motor having a stator according to the aforementioned disclosure is also provided, wherein a rotor including permanent magnets is arranged within the stator core. In this way, the induction motor / permanent magnet excitation electric motor achieves functional integrity.

[0016] In a preferred embodiment of an induction motor / permanent magnet excitation electric motor, it is directly coupled to a two-level inverter. The increased inductance of the stator according to the present invention in an induction motor / permanent magnet excitation electric motor reduces harmonic oscillations in the current, allowing the motor to be operated directly on a two-level inverter without additional measures. Therefore, the use of upstream filters or operation with expensive multilevel converters is obsolete.

[0017] The features disclosed above can be combined as desired, provided this is technically feasible and does not contradict one another. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Further advantageous developments of the invention are characterized in the dependent claims or are described in detail below together with the description of preferred embodiments of the invention with reference to the accompanying drawings.

[0019] Figure 1 A schematic cross-sectional view of an induction machine / permanent magnet excited electric motor with a rotor and a stator with 6 poles or 6 slots, including a soft magnetic shield and non-magnetic connecting elements, is shown.

[0020] Figure 2 Another schematic cross-sectional view of an induction machine / permanent magnet excited electric motor with a rotor and a stator with 6 poles or 6 slots, including a soft magnetic shield and non-magnetic connecting elements,

[0021] Figure 3 A schematic cross-sectional view of an induction machine / permanent magnet excited electric motor with a rotor and a 12-pole or 12-slot stator, including a soft magnetic shield and non-magnetic connecting elements, is shown.

[0022] Figure 4 Another schematic cross-sectional view of an induction machine / permanent magnet excited electric motor with a rotor and a stator with 6 poles or 6 slots, including a soft magnetic shield and non-magnetic connecting elements, and

[0023] Figure 5 Another schematic cross-sectional view of an induction machine / permanent magnet excited electric motor with a rotor and a stator with 12 poles or 12 slots is shown, including a soft magnetic shield and non-magnetic connecting elements. DETAILED DESCRIPTION

[0024] The accompanying drawings are exemplary schematic diagrams. The same reference numerals in the accompanying drawings refer to the same functional features and / or structural features.

[0025] exist Figure 1 A schematic cross-sectional view of an induction motor / permanent magnet excited electric motor with a rotor 8 and a stator with six poles or six slots is disclosed, including a soft magnetic shield 5 and non-magnetic connecting elements 6. The stator of the permanent magnet excited electric motor / induction motor comprises a laminated core 1 consisting of a stator core 11 and a yoke winding 2 with six poles or six slots. The laminated core 1 is constructed in one piece.

[0026] The rotor 8 also includes permanent magnets and is arranged within the stator core 11. The induction machine / permanent magnet excited electric motor is also directly coupled to a 2-level inverter (not shown).

[0027] The yoke winding 2 constructed with 6 poles or 6 slots also includes an inner winding part 21 and an outer winding part 22, wherein the inner winding part is arranged radially in the stator core 11 in the corresponding winding receptacle 3, and the outer winding part is arranged radially outside the stator core 11 on the outer surface 4 of the laminated core 1.

[0028] The inner winding part 21 and the outer winding part 22 are connected to each other via a stator reversal, and the respective winding receptacles 3 are designed as slots. Furthermore, a soft-magnetic shield 5 is formed around the entire circumference of the outer winding part 22 .

[0029] Six non-magnetic connecting elements 6 are arranged between the stator core 11 and the soft magnetic shield 5. The non-magnetic connecting elements 6 contact the stator core 11 and the soft magnetic shield ring 5. The non-magnetic connecting elements 6 are made of plastic and each non-magnetic connecting element 6 is arranged between adjacent winding poles 7 of the winding 2. In addition, the corresponding non-magnetic connecting elements 6 are spaced apart from the corresponding adjacent winding poles 7 of the winding 2.

[0030] Since the following embodiments have substantially the same functional features and / or structural features, only the different features are mentioned below.

[0031] Figure 2 Another schematic sectional view of an induction machine / permanent magnet excited electric motor with a rotor 8 and a 6-pole or 6-slot stator is shown, including a soft magnetic shield 5 and non-magnetic connecting elements 6. The yoke winding 2 of the stator is 6-pole or 6-slot, and the non-magnetic connecting elements 6 are cast parts formed via corresponding outer winding parts 22. The corresponding winding receptacles 3 are also designed as slots.

[0032] exist Figure 3 , a schematic cross-sectional view of an induction machine / permanent magnet excited electric motor with a rotor 8 and a 12-pole or 12-slot stator is shown, including a soft magnetic shield 5 and non-magnetic connecting elements 6. The corresponding winding receptacles 3 are designed as slots, and the yoke winding 2 of the stator has 12 poles or 12 slots.

[0033] Figure 4 Another schematic cross-sectional view of an induction machine / permanent magnet excited electric motor with a rotor 8 and a 6-pole or 6-slot stator is shown, including a soft magnetic shield 5 and non-magnetic connecting elements 6. In the illustrated variant, the stator yoke winding 2 is designed with 6 poles or 6 slots, and the non-magnetic connecting elements 6 are cast parts formed via the corresponding outer winding parts 22. Furthermore, the corresponding winding receptacles 3 have no slots.

[0034] exist Figure 5, another schematic sectional view of an induction machine / permanent magnet excited electric motor with a rotor 8 and a 12-pole or 12-slot stator, including a soft magnetic shield 5 and a non-magnetic connecting element 6. The yoke winding 2 of the stator is designed as a 12-pole or 6-slot device, and the non-magnetic connecting element 6 is a cast part formed via the corresponding outer winding part 22. Furthermore, the corresponding winding receptacle 3 has no slots.

[0035] The embodiments of the present invention are not limited to the preferred exemplary embodiments given above. Rather, many variations of the illustrated implementation are conceivable, even in fundamentally different embodiments.

Claims

1. A stator for an electric motor / induction motor for permanent magnet excitation, the stator comprising a laminated core (1) formed by a stator core (11) and a yoke winding (2), wherein the yoke winding (2) comprises an inner winding part (21) and an outer winding part (22), the inner winding part being arranged radially within the stator core (11) in at least one winding receptacle (3), and the outer winding part being arranged radially outside the stator core (11) on an outer surface (4) of the laminated core (1), wherein: A soft magnetic shielding portion (5) is constructed around the entire circumference of the outer winding portion (22), wherein at least one non-magnetic connecting element (6) is arranged between the stator core (11) and the soft magnetic shielding portion (5), and the non-magnetic connecting element contacts the stator core (11) and the soft magnetic shielding portion (5). The at least one non-magnetic connecting element (6) is made of plastic and one non-magnetic connecting element (6) is arranged between adjacent winding poles (7) of the yoke winding (2), and the corresponding non-magnetic connecting elements (6) are arranged spaced apart from the corresponding adjacent winding poles (7) of the yoke winding (2).

2. The stator according to claim 1, wherein: The laminated core (1) is constructed in one piece.

3. The stator according to claim 1 or 2, wherein: The at least one non-magnetic connecting element (6) is a cast part formed via the outer winding part (22).

4. The stator according to claim 1 or 2, wherein: The at least one winding receptacle (3) is designed as a slot.

5. The stator according to claim 1 or 2, wherein: The yoke winding (2) is constructed with 6 poles or 6 slots.

6. The stator according to claim 1 or 2, wherein: The yoke winding (2) is constructed with 12 poles or 12 slots.

7. An induction motor / permanent magnet excited electric motor having a stator according to any one of the preceding claims, wherein A rotor (8) including permanent magnets is arranged within the stator core (11).

8. The induction motor / permanent magnet excitation electric motor according to claim 7, wherein: The induction motor / permanent magnet excited electric motor is directly coupled to a 2-level inverter.

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