A drive motor rotor structure

Abstract

The application provides a driving motor rotor structure, which comprises a core, a central shaft hole is arranged on the core, a first positioning slot is arranged on the core at the outer periphery of the central shaft hole and is spaced in the circumferential direction, the first positioning slot comprises two magnetic steel slots and an insert mounting hole arranged between the two magnetic steel slots, a first magnetic steel is arranged in the magnetic steel slot, an insert is arranged in the insert mounting hole, the shape of the insert mounting hole is matched with the shape of the insert, and the height direction of the insert extends along the radial direction of the core. The insert is arranged between the two magnetic steel slots, and the height direction of the insert extends along the radial direction of the core, so that the strength of the part between the two magnetic steel slots can be effectively increased, the rotor strength is increased, and the core punching sheet is prevented from being deformed due to excessive centrifugal force during rotation. The insert is made of low-permeability material. The insert made of low-permeability material can effectively reduce magnetic leakage.

Description

A rotor structure for a drive motor Technical Field

[0001] This invention relates to the field of machinery, and more particularly to electric motors, especially a rotor structure for a drive motor. Background Technology

[0002] Currently, electric motors are trending towards miniaturization and higher speeds. High-speed operation generates significant centrifugal force, causing rotor deformation. In severe cases, the rotor may rub against the stator, severely impacting motor performance. In current permanent magnet synchronous motors, the rotor core contains magnetic slots, connected to each other and to the rotor's outer circumference via magnetic bridges. To limit magnetic leakage, the magnetic flux at the magnetic bridge location is typically saturated, and a smaller bridge width results in better magnetic isolation. However, in existing technology, the magnetic bridges have relatively poor strength. High-speed operation generates significant centrifugal force, leading to stress concentration at the bridge location. Excessive centrifugal force can cause the magnetic bridge to break. Increasing the bridge width, on the other hand, increases magnetic leakage, degrading motor performance. Summary of the Invention

[0003] The purpose of this invention is to provide a drive motor rotor structure to solve the technical problem of low strength in the rotor magnetic bridge section of the prior art.

[0004] The present invention provides a drive motor rotor structure, including an iron core, a central shaft hole on the iron core, and a plurality of first positioning grooves spaced circumferentially around the outer periphery of the central shaft hole on the iron core. Each first positioning groove includes two magnet slots and an insert mounting hole disposed between the two magnet slots. A first magnet is disposed in the magnet slot, and an insert is disposed in the insert mounting hole. The shape of the insert mounting hole is adapted to the shape of the insert. The height direction of the insert extends radially along the iron core, and the insert is made of a low magnetic permeability material.

[0005] Preferably, each of the first positioning slots contains one insert.

[0006] Preferably, the first positioning groove is connected to the outer circle of the iron core to form a hollow structure.

[0007] Preferably, two second positioning grooves are provided on the iron core between the first positioning groove and the outer circle of the iron core, a magnetic bridge is provided between the two second positioning grooves, a second magnet is provided in each of the second positioning grooves, and the second positioning grooves are connected to the outer circle of the iron core to form a hollow structure.

[0008] Preferably, the insert comprises a three-layer structure, which is distributed along the height direction of the insert and consists of region a, region b, and region c. Region b is close to the outer circle of the iron core, region c is close to the central shaft hole of the iron core, and region a is located between region b and region c.

[0009] Preferably, in terms of width, the maximum width of area a > the maximum width of area c > the maximum width of area b; and in terms of height, the height of area c > the height of area b > the height of area a.

[0010] Preferably, each layer of the insert has symmetrically distributed protruding teeth on both sides. The insert in region b has a plurality of symmetrically distributed protruding teeth on both sides, and the maximum width formed by each symmetrical protruding tooth in region b decreases from the outer circle of the iron core toward the central shaft hole. The insert in region c has a plurality of symmetrically distributed protruding teeth on both sides, and the maximum width formed by each symmetrical protruding tooth in region c increases from the outer circle of the iron core toward the central shaft hole.

[0011] Preferably, the thickness of the protruding tooth decreases from the inside to the outside in the height direction of the insert.

[0012] Preferably, the number of protruding teeth on one side of both region b and region c is odd.

[0013] Preferably, the number of protrusions on each side of the b and c regions is three, and the center width of the insert is W.

[0014] The maximum overall width of the insert corresponding to the three protrusions in area b and the center width of the insert satisfy the following relationship:

[0015] Wb3=1.85*W, Wb2=1.75*W, Wb1=1.64*W;

[0016] The maximum overall width of the insert corresponding to the three protrusions in area c and the center width of the insert satisfy the following relationship:

[0017] Wc3=2.56*W, Wc2=1.99*W, Wc1=1.69*W.

[0018] Preferably, the protruding teeth in area a of the insert are bent upward to form an embracing structure, and the embracing structure contacts the side of the magnet groove of the first positioning groove near the outer circle of the iron core, and the contact surface is set as the first plane.

[0019] Preferably, the circumferential structure is provided with a second plane that contacts the first magnet.

[0020] Preferably, the top surface of region b, the surface of the protrusion of region b, the bottom surface of region c, and the surface of the protrusion of region c are each equipped with a gasket structure.

[0021] Preferably, the outer surface of the insert is coated with a layer of semi-cured expandable material.

[0022] Compared with the prior art, the present invention has positive and obvious effects. The present invention sets an insert between the two magnet slots, and the height direction of the insert extends radially along the iron core, which can effectively increase the strength of the part between the two magnet slots, increase the rotor strength, and prevent the iron core laminations from deforming due to excessive centrifugal force during rotation. Attached Figure Description

[0023] Figure 1 is a front view schematic diagram of a drive motor rotor structure according to the present invention.

[0024] Figure 2 is a schematic diagram of the iron core in a drive motor rotor structure according to the present invention.

[0025] Figure 3 is a three-dimensional schematic diagram of a drive motor rotor structure according to the present invention.

[0026] Figure 4 is a schematic diagram of an insert in a drive motor rotor structure according to the present invention.

[0027] Figure 5 is a schematic diagram of the maximum equivalent stress of the iron core corresponding to the ring-shaped structure of the drive motor rotor structure of the present invention.

[0028] Figure 6 is a schematic diagram of the maximum equivalent stress of the insert with a ring-shaped structure in a drive motor rotor structure according to the present invention.

[0029] Figure 7 is a schematic diagram of the maximum equivalent stress of the iron core corresponding to the non-circling structure of the rotor structure of the drive motor of the present invention.

[0030] Figure 8 is a schematic diagram of the maximum equivalent stress of the insert of the non-circling structure of the drive motor rotor structure of the present invention.

[0031] Figure 9 is a schematic diagram of a drive motor rotor structure with a shim structure according to the present invention.

[0032] Figure 10 is a schematic diagram of the iron core corresponding to the pad structure of a drive motor rotor structure according to the present invention.

[0033] Figure 11 is a schematic diagram of region b with a shim structure of a drive motor rotor structure according to the present invention.

[0034] Figure 12 is a schematic diagram of section c with a shim structure of a drive motor rotor structure according to the present invention.

[0035] Figure 13 is a schematic diagram of a drive motor rotor structure with a semi-cured expandable material according to the present invention.

[0036] Figure 14 is a schematic diagram of region b with semi-cured expandable material in a drive motor rotor structure according to the present invention.

[0037] Figure 15 is a schematic diagram of region c with semi-cured expandable material in a drive motor rotor structure according to the present invention. Detailed Implementation

[0038] The present invention will be further described below with reference to embodiments, but the present invention is not limited to these embodiments. Any similar variations of the present invention should be included within the scope of protection of the present invention. The directional terms such as up, down, front, back, left, right, center, inner, outer, length direction, and width direction in the present invention are defined based on the orientations shown in the accompanying drawings. The use of directional terms is only for the convenience of clear description and is not a limitation on the technical solution.

[0039] As shown in Figures 1-3, the present invention provides a drive motor rotor structure, including an iron core 1, a central shaft hole 2 on the iron core 1, and a plurality of first positioning grooves 3 spaced circumferentially around the outer periphery of the central shaft hole 2 on the iron core 1. Each first positioning groove 3 includes two magnet slots and an insert mounting hole 5 disposed between the two magnet slots. A first magnet 4 is disposed in the magnet slot, and an insert 6 is disposed in the insert mounting hole 5. The shape of the insert mounting hole 5 is adapted to the shape of the insert 6. The height direction of the insert 6 extends radially along the iron core 1, and the insert 6 is made of a low magnetic permeability material.

[0040] In one embodiment, the first positioning groove 3 is V-shaped.

[0041] In one embodiment, the iron core 1 is formed by stacking a plurality of iron core laminations.

[0042] The present invention embeds an insert 6 between two magnetic steel slots to replace the existing magnetic isolation bridge. The height direction of the insert 6 extends radially along the iron core 1. The insert 6 is made of a low magnetic permeability material, which can effectively reduce magnetic leakage. The low magnetic permeability characteristic allows the space occupied by the insert 6 to be larger than that of the existing magnetic isolation bridge, thereby improving the strength of the structure.

[0043] Preferably, the low magnetic permeability material is 6061 aluminum alloy.

[0044] 6061 aluminum alloy is a low-magnetic-permeability material with high yield strength. The high yield strength allows insert 6 to withstand greater force under the same size, reducing radial deformation caused by centrifugal force, ensuring the reliability of the connection strength, and reducing the risk of rotor rubbing.

[0045] Preferably, as shown in Figures 1-3, the number of inserts 6 in each first positioning groove 3 is one.

[0046] Preferably, as shown in Figures 1-3, the first positioning groove 3 is connected to the outer circle of the iron core 1 to form a hollow structure.

[0047] This design uses a hollow structure to form a non-magnetic bridge connection, which can further reduce magnetic leakage and improve motor performance.

[0048] Preferably, as shown in Figures 1-3, two second positioning grooves 7 are provided on the iron core 1 between the first positioning groove 3 and the outer circle of the iron core 1, a magnetic bridge is provided between the two second positioning grooves 7, and a second magnet 8 is provided in each of the second positioning grooves 7. The second positioning grooves 7 are connected to the outer circle of the iron core 1 to form a hollow structure.

[0049] This design uses a hollow structure to form a non-magnetic bridge connection, which can further reduce magnetic leakage and improve motor performance.

[0050] In one embodiment, the two second positioning slots 7 are symmetrically distributed in a V-shape or arranged in a straight line.

[0051] Preferably, as shown in Figure 4, the insert 6 includes a three-layer structure, which is distributed along the height direction of the insert 6 and consists of region a, region b and region c. Region b is close to the outer circle of the iron core 1, region c is close to the central shaft hole 2 of the iron core 1, and region a is located between region b and region c.

[0052] Preferably, in terms of width, the maximum width of area a > the maximum width of area c > the maximum width of area b; and in terms of height, the height of area c > the height of area b > the height of area a.

[0053] The iron core 1 and the insert mounting hole 5 are engaged by the convex teeth 61 to prevent the insert 6 from rotating relative to the iron core, thus playing a positioning role. Since the changes in the inner layer structure of the iron core 1 have little impact on the electromagnetic performance, the area occupied by region c is designed to be larger to increase strength and reduce stress concentration and radial deformation.

[0054] Preferably, as shown in Figure 4, each layer of the insert 6 has symmetrically distributed protruding teeth 61 on both sides. The insert 6 in region b has a plurality of symmetrically distributed protruding teeth 61 on both sides. The maximum width formed by each symmetrical protruding tooth 61 in region b decreases from the outer circle of the iron core 1 towards the central shaft hole 2. The insert 6 in region c has a plurality of symmetrically distributed protruding teeth 61 on both sides. The maximum width formed by each symmetrical protruding tooth 61 in region c increases from the outer circle of the iron core 1 towards the central shaft hole 2.

[0055] The core 1 is weaker closer to region a, so the insert 6 closer to region a is designed to be narrower, thereby reducing the contact area between the insert 6 and the core 1 and thus bearing less centrifugal force. The core 1 is stronger closer to region b or region c, so the width of the insert 6 is increased, thereby increasing the contact area between the insert 6 and the core 1 and thus bearing more centrifugal force.

[0056] In one embodiment, the tooth tip of insert 6 corresponds to the tooth root of iron core 1, and the tooth tip of iron core 1 corresponds to the tooth root of insert 6. The tooth tip and tooth root of insert 6, and the tooth root and tooth tip of iron core 1, are all rounded to reduce local stress concentration.

[0057] The protruding teeth 61 increase the contact area between the insert 6 and the iron core 1, preventing the insert 6 from falling off and increasing the rotor strength. The insert 6 uses a multi-tooth surface contact method to distribute the load generated by centrifugal force and reduce stress concentration in local areas.

[0058] Preferably, as shown in Figure 4, the thickness of the protruding tooth 61 decreases from the inside to the outside in the height direction of the insert 6.

[0059] Preferably, as shown in Figure 4, the number of protruding teeth 61 on one side of both region b and region c is odd.

[0060] Preferably, as shown in Figure 4, the number of protrusions 61 on regions b and c is three each, and the center width of the insert 6 is W.

[0061] The maximum width of the insert 6 corresponding to the three protrusions 61 in area b and the center width of the insert 6 satisfy the following relationship:

[0062] Wb3=1.85*W, Wb2=1.75*W, Wb1=1.64*W;

[0063] The maximum width of the insert 6 corresponding to the three protrusions 61 in area c and the center width of the insert 6 satisfy the following relationship:

[0064] Wc3=2.56*W, Wc2=1.99*W, Wc1=1.69*W.

[0065] At this ratio, its ability to withstand stress is maximized.

[0066] Preferably, as shown in Figures 1, 3 and 4, the protruding teeth 61 in area a of the insert 6 bend upward to form an encircling structure 62. The encircling structure 62 contacts the side of the magnet groove of the first positioning groove 3 near the outer circle of the iron core 1, and the contact surface is set as the first plane 63.

[0067] In one embodiment, the width of the first plane 63 is 1.5-2 mm, and increasing the contact size can effectively reduce the maximum stress on the iron core 1. The thickness of the first plane 63 portion of the a-region protrusion 61 is 0.7-1.4 mm.

[0068] Preferably, as shown in Figure 4, the circumferential structure 62 is provided with a second plane 64 that contacts the first magnet 4.

[0069] In one embodiment, the width of the second plane 64 is 0.7 mm.

[0070] The purpose of the annular structure 62 is twofold: first, to prevent deformation of the core laminations due to excessive centrifugal force during high-speed rotor operation; and second, to better secure the first magnet 4 in the first positioning groove 3. Figures 6 and 8 show the force diagrams of the insert 6 with and without the annular structure 62, respectively. Figures 5 and 7 show the force diagrams of the core 1 with and without the annular structure 62, respectively. In Figure 5, the maximum force on the core 1 with the annular structure 62 is 448.03 MPa, while in Figure 7, the maximum force on the core 1 without the annular structure 62 increases to 468.91 MPa. The annular structure 62 effectively reduces the force on the core 1.

[0071] Preferably, as shown in Figures 9-12, the top surface of region b, the surface of the protrusion 61 in region b, the bottom surface of region c, and the surface of the protrusion 61 in region c are each equipped with a gasket structure 9.

[0072] A shim structure 9 is added at the point of maximum stress between the core 1 and the insert 6. The detailed installation position of the shim structure 9 is shown in Figures 11 and 12. The shim structure 9 helps to reduce stress concentration at the location of high stress and enhances the strength of the contact surface. In addition, the contact surface between the core 1 and the insert 6 is subjected to normal and tangential loads for a long time. The insert 6 is made of metal, which is prone to fatigue failure such as pitting and spalling under these conditions. Therefore, selecting a wear-resistant material for the shim helps to improve the fatigue performance at this location.

[0073] Preferably, as shown in Figures 13-15, the outer surface of the insert 6 is coated with a layer of semi-cured expandable material 10.

[0074] In one embodiment, the semi-cured expandable material 10 is a semi-cured expandable epoxy adhesive.

[0075] Insert 6 is coated with semi-cured expandable epoxy adhesive. After assembly, it is heat-treated, which can effectively fix insert 6 in insert mounting hole 5. This helps to reduce stress concentration at high stress locations, enhances the strength of the contact surface, and prevents fatigue failure such as pitting and peeling.

[0076] In this invention, all parts not described in detail adopt well-known solutions from the prior art.

Claims

1. A drive motor rotor structure, comprising an iron core, wherein a central shaft hole is provided on the iron core, characterized in that, A plurality of first positioning grooves are circumferentially spaced around the outer periphery of the central shaft hole on the iron core. Each first positioning groove includes two magnetic slots and an insert mounting hole between the two magnetic slots. A first magnet is placed in the magnetic slot, and an insert is placed in the insert mounting hole. The insert mounting hole is adapted to the shape of the insert. The height direction of the insert extends radially along the iron core. The insert is made of a low-permeability material. The insert includes a three-layer structure distributed along the height direction of the insert, namely region a, region b, and region c. Region b is close to the outer circle of the iron core, region c is close to the central shaft hole of the iron core, and region a is located between region b and region c. Each layer of the insert has symmetrically distributed protrusions on both sides. The insert in region b has a plurality of symmetrically distributed protrusions on both sides, and the maximum width formed by each symmetrical protrusion in region b decreases from the outer circle of the iron core towards the central shaft hole. The insert in region c has a plurality of symmetrically distributed protrusions on both sides, and the maximum width formed by each symmetrical protrusion in region c increases from the outer circle of the iron core towards the central shaft hole.

2. The drive motor rotor structure according to claim 1, characterized in that, The number of inserts in each first positioning slot is one.

3. The drive motor rotor structure according to claim 1, characterized in that, The first positioning groove is connected to the outer circle of the iron core, forming a hollow structure.

4. The drive motor rotor structure according to claim 1, characterized in that, Two second positioning grooves are provided on the iron core between the first positioning groove and the outer circle of the iron core. A magnetic bridge is provided between the two second positioning grooves. A second magnet is provided in each of the second positioning grooves. The second positioning grooves are connected to the outer circle of the iron core to form a hollow structure.

5. A drive motor rotor structure according to claim 1, characterized in that, In terms of width, the maximum width of area a > the maximum width of area c > the maximum width of area b; in terms of height, the height of area c > the height of area b > the height of area a.

6. The drive motor rotor structure according to claim 1, characterized in that, The thickness of the protruding teeth decreases from the inside to the outside in the height direction of the insert.

7. The drive motor rotor structure according to claim 1, characterized in that, The number of protruding teeth on one side of both regions b and c is odd.

8. The drive motor rotor structure according to claim 1, characterized in that, The number of protrusions on each side of regions b and c is three. Let the center width of the insert be W. The maximum overall width of the insert corresponding to the three protrusions in region b and the center width of the insert satisfy the following relationship: Wb3=1.85*W, Wb2=1.75*W, Wb1=1.64*W. The maximum overall width of the insert corresponding to the three protrusions in region c and the center width of the insert satisfy the following relationship: Wc3=2.56*W, Wc2=1.99*W, Wc1=1.69*W.

9. A drive motor rotor structure according to claim 1, characterized in that, The protruding teeth in area a of the insert bend upward to form an embracing structure. The embracing structure contacts the side of the magnet groove of the first positioning groove near the outer circle of the iron core, and the contact surface is set as the first plane.

10. A drive motor rotor structure according to claim 9, characterized in that, The encircling structure is provided with a second plane that contacts the first magnet.

11. A drive motor rotor structure according to claim 1, characterized in that, Each of the insert's b-area top surface, b-area tooth surface, c-area bottom surface, and c-area tooth surface is equipped with a gasket structure.

12. A drive motor rotor structure according to claim 1, characterized in that, The outer surface of the insert is coated with a layer of semi-cured expandable material.

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