Disclosed is a disc motor rotor with a composite magnetic pole structure

Abstract

The application discloses a disc motor rotor with a pole-shoe composite magnetic pole structure and relates to the field of electric motors. The disc motor rotor comprises a rotor support disc with a central hole, the one side surface of the rotor support disc is provided with a groove, the groove is used for mounting a rotor iron core and a composite magnetic pole, the rotor iron core is in a ring structure, is arranged at the bottom of the groove, is tightly attached to the rotor support disc, the surface of the side of the rotor iron core away from the rotor support disc is provided with T-shaped baffles which are distributed along the radial direction, the T-shaped baffles equally divide the rotor iron core along the circumference into a plurality of fan-shaped spaces, the composite magnetic pole is mounted in the fan-shaped space on the rotor iron core, the composite magnetic pole comprises a permanent magnet and a pole shoe, and the surface of the permanent magnet is mounted with the pole shoe which is made of a composite soft magnetic material. In the application, the pole shoe on the surface of the permanent magnet can adjust the arc size, generate sinusoidal air gap magnetic density, make the motor output torque smooth, the pole shoe can protect the permanent magnet from losing magnetism under the action of a demagnetizing field, the motor weak magnetic capacity is improved, the pole shoe is easy to process, and the disc motor rotor is suitable for batch production.

Description

Technical Field

[0001] The present invention relates to the technical field of electric motors, in particular to a disc-type motor rotor with a pole shoe composite magnetic pole structure. Background Art

[0002] Most disc motor rotor permanent magnets use a surface-mount design, with the magnets facing the stator core directly. Harmonic magnetic fields in the air gap can generate eddy currents in the permanent magnets, causing them to heat up. Even during short circuits or other fault conditions, the demagnetization field caused by the transient high current can directly act on the permanent magnets, causing them to demagnetize and degrade motor performance, even leading to inoperability. Furthermore, because the thickness of the permanent magnets in this surface-mounted permanent magnet pole structure is equivalent to the air gap, the stator winding's quadrature and direct-axis inductances are very similar, resulting in poor field-weakening capability. Summary of the Invention

[0003] The purpose of the present invention is to provide a disc motor rotor with a pole shoe composite magnetic pole structure to solve the problems existing in the above-mentioned prior art, protect the permanent magnets from demagnetization, improve the motor's magnetic weakening capability, and be easy to process and implement, suitable for mass production.

[0004] To achieve the above-mentioned objectives, the present invention provides the following solution: The present invention provides a disc-type motor rotor with a pole shoe composite magnetic pole structure, comprising a rotor support disk with a disc-shaped cross-section and a central opening, a surface of one side of the rotor support disk being provided with a basin-shaped groove, the groove being used to install the rotor core and the composite magnetic pole; the rotor core is an annular structure, arranged at the bottom of the groove, and tightly fitted with the rotor support disk, a plurality of radially distributed T-shaped baffles are evenly arranged on the surface of the rotor core away from the rotor support disk, the T-shaped baffles divide the rotor core into a plurality of fan-shaped spaces equidistantly along the circumference; the composite magnetic poles are installed in the plurality of fan-shaped spaces on the rotor core; the composite magnetic poles include permanent magnets, and pole shoes are installed on the surface of the permanent magnets.

[0005] Optionally, the lower surface of the permanent magnet fits with the bottom surface of the rotor core, and the upper surface of the permanent magnet fits with the lower surface of the pole shoe; the height of the composite magnetic pole is equal to the height of the T-shaped baffle.

[0006] Optionally, the T-shaped baffle includes a vertical plate connected to the rotor core, and the end of the vertical plate is connected to a horizontal limit plate; the two sides of the upper surface of the pole shoe of the composite magnetic pole are respectively in contact with the horizontal limit plates of the T-shaped baffle; the upper surface of the pole shoe is a smooth arc-shaped convex structure, and horizontal transition parts are symmetrically arranged on both sides of the arc-shaped convex structure, and the width of the horizontal transition part is equal to half the width of the horizontal limit plate.

[0007] Optionally, a fixing ring is connected to the inner side of the rotor core, and the fixing ring is located between the inner side surface of the groove and the bottom of the composite magnetic pole.

[0008] Optionally, a first through hole is provided on the composite magnetic pole, a second through hole is provided on the rotor core, and a threaded hole is provided on the rotor support plate. The first through hole, the second through hole and the threaded hole are relatively arranged, and bolts or rivets are fixedly inserted into the first through hole, the second through hole and the threaded hole.

[0009] Optionally, the rotor core is formed by winding a high-permeability silicon steel strip, or is manufactured by using an amorphous magnetic silicon steel strip.

[0010] Optionally, the rotor support disk is made of high-strength aluminum alloy, and an annular raised baffle is provided on the outer circumference of one side of the rotor support disk where a groove is opened; the fixing ring is arranged at the inner side wall of the groove and abuts against the inner side surface of the rotor core; the annular raised baffle and the fixing ring can jointly limit the radial sliding of the rotor core.

[0011] Optionally, the pole shoe is a composite soft magnetic material pole shoe, i.e., an SMC pole shoe; the surface of the pole shoe is in an eccentric air gap shape.

[0012] Optionally, two pole shoes with the same structure are symmetrically arranged on the surfaces on both sides of the permanent magnet, and the curvature of the pole shoe surface can be adjusted; the pole shoes can isolate the eddy current effect of high-frequency harmonics on the permanent magnet, preventing eddy current heating and demagnetization of the permanent magnet.

[0013] Compared with the prior art, the present invention has achieved the following technical effects:

[0014] The present invention has strong engineering feasibility. The rotor assembly adopts T-shaped baffles and screws or rivets to limit the axial and tangential movement of the permanent magnet. The structural strength is reliable and the composite magnetic poles can be effectively prevented from being thrown out when the rotor rotates at high speed. There is no need to use processes such as gluing to fix the permanent magnets and pole shoes, which simplifies the mass production process and effectively saves mass production time. In the composite magnetic pole structure of the disk motor with pole shoes, the pole shoes are made of SMC material. Since SMC has the advantages of good magnetic conductivity and easy molding and processing, and SMC can be processed into an eccentric air gap shape on the surface, the permanent magnet and the SMC composite magnetic pole can form a sinusoidal air gap magnetic flux waveform, improve the sinusoidality of the air gap magnetic field, reduce the motor torque fluctuation index, and improve the motor NVH performance. The radian of the pole shoe can be adjusted as needed to reduce the harmonic content in the motor, effectively reduce the eddy current effect in the permanent magnet, and protect the permanent magnet from demagnetization due to the demagnetization field. Due to the use of SMC composite magnetic poles, the quadrature and direct axis inductances of the motor are different, which improves the weak magnetic capability of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 Schematic diagram of the composite magnetic pole structure with pole shoes in Example 1;

[0017] Figure 2 Schematic diagram of the rotor core structure in Example 1;

[0018] Figure 3 This is a schematic diagram of the structure after the composite magnetic poles are embedded in the rotor core in Example 1;

[0019] Figure 4 A partial cross-sectional view of the composite magnetic poles in Example 1 after being embedded in the rotor core and combined with the rotor support disc;

[0020] Figure 5 Schematic diagram of the local structure of the composite magnetic pole with pole shoes in Example 2;

[0021] Figure 6 Schematic diagram of the composite magnetic pole structure with pole shoes in Example 2;

[0022] Figure 7 Schematic diagram of the rotor structure of a disc-type motor with a pole shoe composite magnetic pole structure in Example 2;

[0023] Figure 8 A cross-sectional view of a disc motor rotor with a pole shoe composite magnetic pole structure in Example 2;

[0024] Among them, 1 is the rotor core, 2 is the T-shaped baffle, 3 is the composite pole with pole shoe, 301 is the permanent magnet, 302 is the pole shoe, 303 is the horizontal transition part, 4 is the rotor support plate, 5 is the fixing ring, 6 is the bolt, 7 is the annular raised baffle, 8 is the first through hole, 9 is the second through hole, 10 is the threaded hole, and 11 is the annular baffle. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] The purpose of the present invention is to provide a disc motor rotor with a pole shoe composite magnetic pole structure to solve the problems existing in the above-mentioned prior art, protect the permanent magnets from demagnetization, improve the motor's magnetic weakening capability, and be easy to process and implement, suitable for mass production.

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Example 1

[0029] The present invention provides a disc-type motor rotor with a pole shoe composite magnetic pole structure, such as Figures 1-4 As shown, the rotor core 1 includes an annular structure, which can be formed by winding silicon steel strips. The rotor core 1 is provided with multiple T-shaped baffles 2, which divide the rotor core 1 into multiple sector-shaped spaces along the circumference. The pole shoe composite magnetic poles 3 are radially inserted into the sector-shaped spaces between the two T-shaped baffles 2. The rotor support disk 4 is configured as a disk with a central opening, and the upper surface is configured as a basin-shaped groove. The rotor core assembly (including the magnetic poles) is placed in the groove of the rotor support disk 4. The outer side surface of the basin-shaped groove restricts radial outward movement of the rotor core assembly. A fixing ring is provided near the inner side wall of the basin-shaped groove, and the fixing ring 5 restricts radial inward movement of the rotor core assembly. In addition, holes are opened on the rotor core 1, the pole shoe composite magnetic poles 3, and the rotor support disk 4, and the rotor core 1, the pole shoe composite magnetic poles 3, and the rotor support disk 4 are fastened together with bolts 6 or rivets. An annular raised baffle 7 is provided on the outer circumference of one side of the rotor support disk 4 where a groove is opened; a fixing ring 5 is provided on the inner side wall of the groove and abuts against the inner side surface of the rotor core 1; the annular raised baffle 7 and the fixing ring 5 can jointly limit the radial sliding of the rotor core 1; the rotor core 1 is provided with N T-shaped baffles 2 along the radial direction, N is an odd number, and the rotor core 1 is divided into M sector-shaped spaces, M is an even number; the pole shoe composite pole 3 is a two-layer composite structure with a sector-shaped cross-section, and the lower layer is a permanent magnet 301; the upper layer is a pole shoe 302 made of SMC, or a pole shoe 302 made of other materials with good magnetic conductivity, such as silicon steel sheets, amorphous silicon steel sheets, etc.; the upper layer is set to a circular arc pole shoe structure; the radian r of the arc can be adjusted according to design requirements to obtain the required sinusoidal air gap magnetic field. The upper surface of the pole shoe 302 is an arc-shaped structure with an arc-shaped protrusion, and a horizontal transition portion 303 is provided near the two side surfaces. The width d of the horizontal transition portion 303 is equal to half the width D of the horizontal limit plate of the T-shaped baffle 2 at the slot of the rotor core 1. The height h of the pole shoe composite pole 3 is equal to the height H of the T-shaped baffle 2 to better adapt to the assembly and fixation needs.

[0030] The lower surface of the permanent magnet 301 of the pole shoe composite magnetic pole 3 is aligned with the surface of the rotor core 1, and the upper surface of the permanent magnet 301 is aligned with the lower surface of the pole shoe 302. The height of the pole shoe composite magnetic pole 3 is equal to the height of the T-shaped baffle 2. During assembly, the pole shoe composite magnetic pole 3 is radially inserted into the fan-shaped space of the rotor core 1 and then assembled with the rotor support plate 4 to form a rotor assembly. The outer arc circumference of the pole shoe composite magnetic pole 3 abuts the inner surface of the annular protrusion of the rotor support plate 4, and the inner arc surface of the pole shoe composite magnetic pole 3 abuts the outer side of the retaining ring 5. To limit axial movement of the rotor core assembly, a first through-hole 8 is formed in the center of the pole shoe composite magnetic pole 3. The rotor core 1 has a second through-hole 9 directly opposite the first through-hole 8. The rotor support plate 4 has threaded holes 10 corresponding to the first through-hole 8 and the second through-hole 9. Bolts 6 can be used to fix the pole shoe composite magnetic pole 3, consisting of the permanent magnet 301 and the pole shoe 302, the rotor core 1, and the rotor support plate 4.

[0031] During assembly, the pole shoe 302 is first fitted with the permanent magnet 301, and then radially inserted from the outside to the inside into the fan-shaped space formed by two adjacent T-shaped baffles 2 of the rotor core 1. The shape of the pole shoe composite pole 3 matches the fan-shaped space of the rotor core 1. The assembled core assembly is then placed into the groove of the rotor support plate 4, and the outer ring of the rotor core 1 is fitted with the annular raised baffle 7 on the outer side of the rotor support plate 4. At this time, the three are fastened together using bolts 6 through the first through-hole 8, the second through-hole 9, and the threaded hole 10. Furthermore, a fixing ring 5 is inserted into the rotor support plate 4 along the inner side of the groove, and the fixing ring 5 is tightly fitted with the inner side of the groove. The fixing ring 5 is then fixed with a locating pin or screw. At this point, the assembly of the entire rotor assembly is completed. The T-shaped baffles 2 of the rotor core 1 and the bolts 6 together limit the axial movement of the rotor assembly to adapt to the axial electromagnetic force of the high-speed rotation of the motor.

[0032] The present invention utilizes the advantages of SMC (composite soft magnetic material) such as good magnetic conductivity and easy molding and processing. SMC can be freely processed into pole shoes with an eccentric air gap surface. The permanent magnet and pole shoe composite magnetic poles can form a sinusoidal air gap magnetic flux waveform, and the curvature of the pole shoe composite magnetic poles can be adjusted as needed to further improve the sinusoidality of the air gap magnetic field. The permanent magnet pole shoe composite magnetic poles can form a sinusoidal air gap magnetic flux waveform, reducing the harmonic content in the motor. The pole shoes can protect the permanent magnets from eddy current effects or demagnetization, significantly reducing the output torque fluctuation of the motor and improving the NVH performance of the entire machine. The rotor structure with magnetic conductive material pole shoes makes the motor's quadrature and direct axis inductance different, improving the motor's weak magnetic capability. The rotor assembly structure of the present invention is easy to process and implement, and is suitable for mass production.

[0033] Example 2

[0034] like Figure 5 、 Figure 6 、 Figure 7 and Figure 8 As shown, in another embodiment, the rotor support disk 4 is made of non-magnetic aluminum alloy material, and the rotor core in the first embodiment is omitted. Pole shoes 302 with the same structure are provided on both sides of the permanent magnet with pole shoe composite pole 3, that is, a double-sided pole shoe structure. The cross-sections of the rotor support disk 4 and the annular baffle 11 are symmetrically arranged. The composite magnetic pole 3 with pole shoes can be effectively fixed by using a screw or rivet fastening structure. The rotor structure with magnetic conductive material pole shoes makes the quadrature and direct axis inductances of the motor different, thereby improving the weak magnetic capability of the motor. The pole shoes isolate the eddy current effect of the high-frequency harmonic magnetic field on the permanent magnet, thereby preventing eddy current heating and demagnetization of the permanent magnet.

[0035] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A disc-type motor rotor with a pole shoe composite magnetic pole structure, characterized in that: The invention comprises a rotor support disk with a disc-shaped cross section and a central opening, wherein a basin-shaped groove is provided on the surface of one side of the rotor support disk, and the groove is used to install the rotor core and the composite magnetic pole; the rotor core is an annular structure, arranged at the bottom of the groove, and tightly fits the rotor support disk, and a plurality of radially distributed T-shaped baffles are evenly arranged on the surface of the rotor core away from the rotor support disk, and the T-shaped baffles divide the rotor core into a plurality of sector-shaped spaces at equal intervals along the circumference; the composite magnetic pole is installed in the plurality of sector-shaped spaces on the rotor core; the composite magnetic pole comprises a permanent magnet, and a pole shoe is installed on the surface of the permanent magnet; the lower surface of the permanent magnet fits with the bottom surface of the rotor core, and the upper surface of the permanent magnet fits with the lower surface of the pole shoe; the height of the composite magnetic pole is equal to The height of the T-shaped baffle; the T-shaped baffle includes a vertical plate connected to the rotor core, and the end of the vertical plate is connected to a horizontal limit plate; the two sides of the upper surface of the pole shoe of the composite magnetic pole are respectively in contact with the horizontal limit plates of the T-shaped baffle; the upper surface of the pole shoe is a smooth arc-shaped convex structure, and horizontal transition parts are symmetrically arranged on both sides of the arc-shaped convex structure, and the width of the horizontal transition part is equal to half the width of the horizontal limit plate; a first through hole is provided on the composite magnetic pole, a second through hole is provided on the rotor core, and a threaded hole is provided on the rotor support plate, the first through hole, the second through hole and the threaded hole are relatively arranged, and bolts or rivets are fixed in the first through hole, the second through hole and the threaded hole; the pole shoe is a composite soft magnetic material pole shoe; the surface of the pole shoe is in the shape of an eccentric air gap.

2. The disc motor rotor with a pole shoe composite magnetic pole structure according to claim 1, characterized in that: The rotor core is formed by winding silicon steel strips, or is manufactured by using amorphous steel magnetic silicon steel strips.

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