Design of a magnet insert for a rotor lamination

Abstract

Product that includes: a rotor plate (20) comprising several cutouts (26, 28, 44, 46), comprising a magnetic holder (64, 66) which is inserted into at least one of the cutouts (44, 46): a first section (48, 68), a second section (50, 70) and a third section (52, 72), wherein the first (48, 68) and second (50, 70) sections are linear and are constructed and arranged to hold a magnet (74), wherein the third section (52, 72) extends outwards from approximately a central point between the first (48, 68) and second (50, 70) sections, wherein the third section (52, 72) is constructed and arranged to bear a load of a centrifugal force of the magnet (74), and wherein the third section (52, 72) is perpendicular to the direction of the centrifugal force of the magnet (74).

Description

TECHNICAL FIELD

[0001] The field to which the disclosure generally belongs includes drive motors. BACKGROUND

[0002] A drive motor may contain a rotor lamination.

[0003] JP 2013-165625 A discloses a method for manufacturing a rotor for a motor with internal permanent magnets. For this purpose, a two-part magnet is inserted into a slot and filled with resin in such a way that the two magnet parts do not touch each other, in order to minimize eddy current losses. A cross-section of the slot comprises a rectangle and a convex shape protruding from a shorter side of the rectangle. SUMMARY OF ILLUSTRATED VARIANTS

[0004] A product comprises a rotor lamination having a plurality of cutouts and a magnet holder inserted into at least one of the cutouts, the magnet holder comprising: a first portion, a second portion, and a third portion, the first and second portions being linear and constructed and arranged to hold a magnet, and the third portion extending outwardly from approximately a central location between the first and second portions, the third portion being constructed and arranged to carry a load from a centrifugal force of the magnet, and the third portion being perpendicular to the direction of the centrifugal force of the magnet.

[0005] Another variation may include a product comprising a rotor lamination comprising: an annular portion including an annular opening at its center, wherein a plurality of first, second, third, and fourth cutouts extend around the circumference of the annular portion; a first set of magnets, wherein the first set of magnets is inserted into the plurality of first and second cutouts; a first set of magnet holders and a second set of magnet holders, wherein the first set of magnet holders is inserted into the plurality of third cutouts and wherein the second set of magnet holders is inserted into the plurality of fourth cutouts; and a second set of magnets, wherein the second set of magnets is inserted into the first and second sets of magnet holders.

[0006] Other illustrative variations within the scope of the invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while disclosing variations within the scope of the invention, are intended for illustrative purposes only and are not intended to limit the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Selected examples of variations within the scope of the invention will be more fully understood from the detailed description and the accompanying drawings, in which: Fig. 1 illustrates a front view of a rotor core in accordance with a number of variants. Fig. Figure 2 illustrates a perspective view of a rotor core in accordance with a number of variants. Fig. 3 illustrates an enlarged view of a rotor lamination in accordance with a number of variants. Fig. Figure 4 illustrates an enlarged view of a rotor lamination in accordance with a number of variants. Fig. 5 illustrates a rear view of a rotor lamination in accordance with a variant. Fig. 6 illustrates a perspective view of a rotor lamination in accordance with a number of variants. DETAILED DESCRIPTION OF ILLUSTRATIVE VARIANTS

[0008] The following description of the variations is merely illustrative and is in no way intended to limit the scope of the invention, its application, or uses.

[0009] With reference to Fig. 1-2, a product includes a rotor lamination magnet holder 64, 66. The magnet holder 64, 66 is constructed and arranged to house a rotor lamination magnet 74 and to reduce the load of the magnet 74 on weak areas of a rotor lamination 20, which may be caused by the centrifugal load of the magnet 74 that may occur when the rotor lamination 20 rotates in a motor assembly, as discussed hereinafter.

[0010] In a number of variations, one or more rotor laminations 20 may be used to form a rotor core 22 for any number of motor assemblies, including, but not limited to, drive motors. The rotor core 22 may be constructed and arranged to rotate about a stator. The relative motion between the rotor core 22 and the stator may generate mechanical or electrical power. A drive motor may be used in any number of vehicles, including, but not limited to, hybrid electric vehicles and / or battery electric vehicles.

[0011] In a number of variations, a rotor lamination 20 may have an annular shape and may include an annular opening 24 at its center. The rotor lamination 20 may comprise a single unit or it may be made up of multiple segments that are interlocked together. The rotor lamination 20 may include a plurality of cutouts 26, 28, 44, 46 that may be arranged around the circumference of the rotor lamination 20. The cutouts 26, 28, 44, 46 may form a pattern around the rotor lamination 20 or they may be randomly distributed throughout the rotor lamination 20 depending on the engine requirements. In one variation, the rotor lamination 20 may include a pattern of a first cutout 26, a second cutout 28, a third cutout 44, and a fourth cutout 46 that may repeat around the circumference of the rotor lamination 20.The rotor lamination 20 may comprise any number of materials, including, but not limited to, electrical steel. A rotor lamination 20 may be formed in any of a number of ways, including, but not limited to, stamping and / or laser cutting.

[0012] With reference to Fig. 3 and Fig. 4, the first and second cutouts 26, 28 may, in a number of variations, each be constructed and arranged to house a first set of magnets 42, as discussed hereinafter.

[0013] The first cutouts 26, 28 may have any number of shapes, including, but not limited to, rectangular, circular, triangular, square, etc. In one variation, the first cutout 26 may be substantially trapezoidal in shape and may receive a first tab 30 and a second tab 32 that may extend from the rotor lamination 20 into the portion of the first cutout 26. The first cutout 26 may include a first end 34 and a second end 36, such as shown in Fig. 3. The first end 34 may extend at an angle from the second end 36. The second cutout 28 may be a mirror image of the first cutout 26 and may form an acute angle with the first cutout 26, such as in Fig. 4. The second ends 36 of the first and second cutouts 26, 28 may be separated by a first web 38 in the rotor lamination 20, as shown in Fig. 4. The first ends 34 of the first and second cutouts 26, 28 may extend toward a bridge 40 that may extend around the circumference of the rotor lamination 20.

[0014] In a number of variations, a first set of magnets 42 may extend through each of the first and second cutouts 26, 28, which may extend around the circumference of one or more rotor laminations 20. The first set of magnets 42 may be pressed into the first and second cutouts 26, 28 or may be held in place by an epoxy. The first set of magnets 42 may include any number of magnets, including, but not limited to, neodymium magnets.

[0015] In a number of variations, the third and fourth cutouts 44, 46 may each be constructed and arranged to accommodate a set of magnet holders 64, 66, as discussed hereinafter. The third and fourth cutouts 44, 46 may be larger than the first and second cutouts 26, 28. The third cutout 44 may have any number of shapes, including, but not limited to, rectangular, circular, triangular, square, etc. In one variation, the third cutout 44 may include a first portion 48, a second portion 50, and a third portion 52. The first and second portions 48, 50 may be linear or straight, respectively. The first portion 48 of the third cutout 44 may extend upwardly from the second portion 50 of the third cutout 44 at an angle.The third portion 52 may extend outwardly from the first and second portions 48, 50 to form an acute angle with the first portion 48 and an obtuse angle with the second portion 50. The first portion 48 may include a recess 54 at its end 56. The second portion 50 may include a rounded end 58. The third portion 52 may include a straight end 60. The ends 56, 58, 60 may each be constructed and arranged to retain the magnet holders 64, 66 and to assist in distributing a load that may arise from the physical force of the second magnets 74 due to the rotation of the rotor laminations 20 about the stator, as discussed hereinafter. The fourth cutout 46 may be a mirror image of the third cutout 44 and may form an acute angle with the third cutout 44, such as shown in FIG. Fig. 4. The ends 58 of the second sections 50 of the third and fourth cutouts 44, 46 may be separated by a second web 62. The ends 56 of the first sections 48 of the third and fourth cutouts 44, 46 may each extend toward the bridge 40 of the rotor lamination 20. The third cutout 44 may be parallel to the first cutout 26, and the fourth cutout 46 may be parallel to the second cutout 28.

[0016] In a number of variations, a first magnet holder 64 may be inserted into the third cutout 44, and a second magnet holder 66 may be inserted into the fourth cutout 46. The first and second magnet holders 64, 66 may each be held in place in any number of variations, including, but not limited to, a transition fit. The magnet holders 64, 66 may each be constructed and arranged to reduce the physical force of the second magnets 74 that may be transmitted to the rotor lamination 20 due to the centrifugal force that may result from the rotation of the rotor core 22 about the stator, as discussed below.

[0017] With reference to Fig. 3, in a number of variations, the first magnet holder 64 may have any number of shapes to fit within the third cutout 44, including, but not limited to, rectangular, circular, triangular, square, etc. In one variation, the first magnet holder 64 may include a first portion 68, a second portion 70, and a third portion 72. The first and second portions 68, 70 may be linear and may be constructed and arranged to house a second magnet 74, as discussed below. The first portion 68 may extend upwardly from the second portion 70 at an angle. The third portion 72 may extend outwardly from approximately the midpoint of the first and second portions 68, 70 and may form an acute angle with the first portion 68 and an obtuse angle with the second portion 70.The third portion 72 of the first magnet holder 64 may be constructed and arranged to support a load from the second magnet 74 as the rotor core 22 rotates around the stator. According to the invention, the third portion 72 is perpendicular to the direction of centrifugal force of the second magnet 74. This may allow the force of the second magnet 74 to be resisted at the thicker section of the first magnet holder 64, rather than at weaker sections of the rotor lamination 20, such as the bridge 40 and / or the second web 62. This may reduce stress on the bridge 40 and / or the second web 62, which may extend the life of the rotor lamination 20, the rotor, and / or the drive motor. This may also allow the design of the rotor lamination 20 to include thinner sections at the second web 62 and the bridge 40, which may improve electromagnetic performance.The second magnet holder 66 may be a mirror image of the first magnet holder 64, such as shown in FIG. Fig. 4. The first and second magnet holders 64, 66 may comprise any number of materials, including, but not limited to, electrical steel and / or a high-temperature plastic. The first and second magnet holders 64, 66 may be formed in any of a number of ways, including, but not limited to, stamping and / or laser cutting.

[0018] With reference to Fig.3-6, in a number of variations, a second set of magnets 74 may be sandwiched into the first and second magnet holders 64, 66. The second set of magnets 74 may include any number of magnets, including, but not limited to, neodymium magnets. The second set of magnets 74 may be sandwiched into the first and second magnet holders 64, 66 in any number of variations, including, but not limited to, a transition fit. This may allow for the assembly of the second set of magnets 74 into the first and second magnet holders 64, 66 without the use of an epoxy, which may reduce and / or eliminate problems in the part due to a mismatch in a coefficient of thermal expansion (CTE) or problems due to epoxy shrinkage.The use of the first and second magnet holders 64, 66 to hold the magnets 74 in place can also enable easy assembly and disassembly of the rotor lamination 20. Therefore, if a magnet 74 becomes demagnetized or malfunctions, a single magnet holder 64, 66 and / or magnet 74 can be easily replaced instead of requiring replacement of the entire rotor lamination 20, which can extend the service life of a rotor and / or drive motor.

[0019] The following description of variations is intended to illustrate components, elements, acts, products, and methods that are considered within the scope of the invention and is in no way intended to limit that scope by what is specifically disclosed or not explicitly disclosed. The components, elements, acts, products, and methods described herein may be combined or rearranged in ways other than those explicitly described herein and still be considered within the scope of the invention.

[0020] Variation 1 may include a product comprising: a magnet holder for a rotor lamination comprising: a first portion, a second portion, and a third portion, wherein the first and second portions are linear and constructed and arranged to hold a magnet, and wherein the third portion extends outwardly from approximately a central location between the first and second portions, and wherein the third portion is constructed and arranged to carry a load from a centrifugal force of the magnet.

[0021] Variant 2 may include a product as disclosed in Variant 1, wherein the third section forms an acute angle with the first section and an obtuse angle with the second section.

[0022] Variant 3 may include a product as disclosed in any of the variants 1 - 2, wherein the magnet holder comprises a steel.

[0023] Variant 4 may include a product as disclosed in any of variants 1-2, wherein the magnet holder comprises a polymer material.

[0024] Variant 5 may include a product as disclosed in any of variants 1-4, further comprising a rotor lamination comprising a plurality of cutouts, and wherein the magnet holder is inserted into at least one of the cutouts.

[0025] Variation 6 may include a product as disclosed in Variation 5, wherein the plurality of cutouts comprise a first set of cutouts, a second set of cutouts, a third set of cutouts, and a fourth set of cutouts, and wherein a first set of magnets is inserted into the first set of cutouts and a second set of magnets is inserted into the second set of cutouts, and wherein a first set of magnet holders is inserted into the third set of cutouts and a second set of magnet holders is inserted into the fourth set of cutouts.

[0026] Variation 7 may include a product as disclosed in any of Variations 5-6, wherein the first set of cutouts and the second set of cutouts are a mirror image of each other, and wherein the third set of cutouts and the fourth set of cutouts are a mirror image of each other.

[0027] Variation 8 may include a product as disclosed in any of Variations 5-8, further comprising a third set of magnets and a fourth set of magnets, wherein the third set of magnets is fitted into the first set of magnet holders and the second set of magnets is inserted into the second set of magnet holders.

[0028] Variation 9 may include a product as disclosed in any of Variations 5-9, wherein the first set of magnet holders is fitted into the first set of cutouts by a transition fit and wherein the second set of magnet holders is fitted into the fourth set of cutouts by a transition fit.

[0029] Variation 10 may include a product as disclosed in any of Variations 5-9, wherein the third set of magnets is transition-fitted into the first set of magnet holders and the fourth set of magnets is transition-fitted into the second set of magnet holders.

[0030] Variation 11 may include a product as disclosed in any of Variations 5-10, further comprising: a rotor core, wherein a plurality of rotor laminations form the rotor core; a stator, wherein the rotor core rotates about the stator; and wherein the first and second magnets generate a centrifugal load on at least one of the rotor laminations as the rotor core rotates about the stator, and wherein the first magnet holder and the second magnet holder are constructed and arranged to carry the centrifugal load away from the at least one rotor lamination.

[0031] Variation 12 may include a product comprising: a rotor lamination comprising: an annular portion including an annular opening at its center, wherein a plurality of first, second, third, and fourth cutouts extend around the circumference of the annular portion; a first set of magnets, wherein the first set of magnets is inserted into the plurality of first and second cutouts; a first set of magnet holders and a second set of magnet holders, wherein the first set of magnet holders is inserted into the plurality of third cutouts and wherein the second set of magnet holders is inserted into the plurality of fourth cutouts; and a second set of magnets, wherein the second set of magnets is inserted into the first and second sets of magnet holders.

[0032] Variation 13 may include a product as disclosed in Variation 12, wherein the first set of magnet holders is fitted into the plurality of third cutouts by a transition fit and wherein the second set of magnet holders is fitted into the plurality of fourth cutouts by a transition fit.

[0033] Variation 14 may include a product as disclosed in any of Variations 12-13, wherein the second set of magnets is fitted into the first and second sets of magnet holders by a transition fit.

[0034] Variation 15 may include a product as disclosed in any of Variations 12-14, wherein the first and second sets of magnet holders are constructed and arranged to convey a load from the second set of magnets away from a bridge section and from a plurality of web sections on the rotor lamination.

[0035] Variation 16 may include a product as disclosed in any of Variations 12-15, wherein the first and second sets of magnet holders include at least one load-bearing member constructed and arranged to support a perpendicular load from the second set of magnets.

[0036] Variation 17 may include a product comprising a rotor core comprising: a plurality of rotor laminations, each comprising an annular portion including an annular opening at its center, wherein a plurality of first, second, third, and fourth cutouts extend around the circumference of the circular portion; a first set of magnets, wherein the first set of magnets is inserted into at least a portion of the plurality of first and second cutouts; a first set of magnet holders and a second set of magnet holders, wherein the first set of magnet holders is inserted into at least a portion of the plurality of third cutouts and wherein the second set of magnet holders is inserted into at least a portion of the plurality of fourth cutouts; and a second set of magnets, wherein the second set of magnets is inserted into the first and second sets of magnet holders.

[0037] Variation 18 may include a product as disclosed in Variation 17, wherein the first and second sets of magnet holders are constructed and arranged to reduce a load from a centrifugal force of the second set of magnets.

[0038] Variation 19 may include a product as disclosed in any of Variations 17-18, wherein the first and second magnet holders comprise a first portion, a second portion, and a third portion, the first and second portions being linear, and the third portion extending outwardly from approximately a central location between the first and second portions, and the third portion being constructed and arranged to support a load from a centrifugal force of a magnet.

[0039] The foregoing description of selected variations within the scope of the invention is illustrative only, and therefore variations or deviations therefrom should not be considered a departure from the spirit and scope of the invention.

Claims

[1] Product that includes: a rotor plate (20) comprising a plurality of cutouts (26, 28, 44, 46), a magnet holder (64, 66) inserted into at least one of the cutouts (44, 46), comprising: a first section (48, 68), a second section (50, 70) and a third section (52, 72), the first (48, 68) and second (50, 70) sections being linear and constructed and arranged to support a magnet (74), the third section (52, 72) extending outwardly from approximately a central location between the first (48, 68) and second (50, 70) sections, the third section (52, 72) being constructed and arranged to carry a load from a centrifugal force of the magnet (74), and the third section (52, 72) being perpendicular to the direction of the centrifugal force of the magnet (74). [2] The product of claim 1, wherein the third portion (52, 72) forms an acute angle with the first portion (48, 68) and an obtuse angle with the second portion (50, 70). [3] The product of claim 1, wherein the plurality of cutouts (26, 28, 44, 46) comprise a first set of cutouts (26), a second set of cutouts (28), a third set of cutouts (44), and a fourth set of cutouts (46), and wherein a first set of magnets (42) is inserted into the first set of cutouts (26) and a second set of magnets (42) is inserted into the second set of cutouts (28), and wherein a first set of magnet holders (64) is inserted into the third set of cutouts (44) and a second set of magnet holders (66) is inserted into the fourth set of cutouts (46). [4] The product of claim 3, wherein the first set of cutouts (26) and the second set of cutouts (28) are a mirror image of each other, and wherein the third set of cutouts (44) and the fourth set of cutouts (46) are a mirror image of each other. [5] The product of claim 3, further comprising a third set of magnets (74) and a fourth set of magnets (74), wherein the third set of magnets (74) is fitted into the first set of magnet holders (64) and the fourth set of magnets (74) is inserted into the second set of magnet holders (66). [6] The product of claim 5, further comprising: a rotor core (22), wherein a plurality of rotor laminations (20) form the rotor core (22); a stator, wherein the rotor core (22) rotates around the stator; and wherein the first (42) and second (74) magnets generate a centrifugal load on at least one of the rotor laminations (20) as the rotor core (22) rotates around the stator, and wherein the first magnet holder (64) and the second magnet holder (66) are constructed and arranged to carry the centrifugal load away from the at least one rotor lamination (20).

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