rotor

Abstract

In order to provide a rotor in which the occurrence of cracks in a resin on an end surface of a magnet is suppressed, a rotor R according to the present disclosure comprises: a rotor core 10 having a first magnet hole 11 that accommodates a first magnet MG1; a first rotor core sheet 20 that is in contact with an axial-direction end surface of the first magnet MG1 and has an opening 21 partially overlapping a placement region S1 in which the first magnet MG1 of the first magnet hole 11 is placed; and a resin part provided between the first magnet MG1 and the first magnet hole 11 and in the opening 21. The opening 21 is not provided at a position overlapping a side part MS of the first magnet MG1 along an orientation direction of the first magnet MG1. The first magnet hole 11 has a first region S2 that does not accommodate the first magnet MG1 and is provided adjacent to the placement region S1 in which the first magnet MG1 is placed. The opening 21 includes a first overlapping portion 22 overlapping the first region S2. The first overlapping portion 22 is provided in the orientation direction of the first magnet MG1.

Description

Rotor

[0001] The present disclosure relates to a rotor.

[0002] Patent Document 1 discloses a rotor including: a core body formed with a through hole opening to a surface; a magnet accommodated in the through hole, both end faces of the magnet arranged in the extending direction of the through hole being positioned inward of the through hole relative to an opening of the through hole; and an insulating material filled in the through hole so as to cover both end faces of the magnet, wherein the core body has a support portion formed on an inner surface of the core body defining the through hole and supporting the magnet.

[0003] Specifically, the core body is formed by laminating a plurality of electrical steel sheets, and an electrical steel sheet positioned at an end on one side has an opening formed with a protrusion that supports an end face of the magnet.

[0004] Then, with the core body arranged with one side facing down, and with the protrusion supporting the lower end face of the magnet accommodated in the through hole, a resin as an insulating material is poured into the through hole from an upper side of the core body, and the resin also flows into the opening formed with the protrusion, thereby closing the opening with the resin and preventing the magnet from being exposed to outside air.

[0005] Japanese Unexamined Patent Application Publication No. 2008-109777

[0006] On the other hand, anisotropic magnets are often used for magnets employed in motors and the like. An anisotropic magnet has a positive coefficient of linear expansion in the orientation direction and a negative coefficient of linear expansion in a direction orthogonal to the orientation direction.

[0007] In Patent Document 1, an opening formed with a protrusion that supports an end face of the magnet, which is provided in an electrical steel sheet positioned at an end on one side of the core body, is configured to straddle an end of the magnet in a direction orthogonal to the orientation direction (hereinafter also simply referred to as the end of the magnet).

[0008] For this reason, in the cooling step after pouring the resin, the magnet expands in the direction orthogonal to the orientation direction, while the resin in the opening tends to contract. However, as described above, since the electrical steel sheet having the opening is positioned on the lower side, the resin in the opening cannot flow in a manner that follows the expansion of the magnet.

[0009] As a result, at the point where the magnet's edge crosses the opening, the magnet's edge expands, applying stress in the opposite direction to the shrinking resin within the opening, which may cause cracks to form in the resin.

[0010] This disclosure has been made in view of these circumstances, and one of its objectives is to provide a rotor that suppresses the occurrence of resin cracks on the end face of the magnet.

[0011] The rotor of the present disclosure comprises a rotor core having a first magnet hole for housing a first magnet; a first rotor core sheet having an opening that contacts the axial end face of the first magnet and partially overlaps the arrangement area of ​​the first magnet hole where the first magnet is placed; and a resin portion provided between the first magnet and the first magnet hole, and within the opening, wherein the opening is not provided in a position that overlaps the side of the first magnet along the orientation direction of the first magnet.

[0012] According to this disclosure, a rotor is provided that suppresses the occurrence of cracks in the resin on the end face of the magnet.

[0013] This is a side view of the rotor of the first embodiment according to the present disclosure. This is a front view of the rotor of the first embodiment according to the present disclosure, viewed from one side in the axial direction. This is a front view of the rotor core of the first embodiment according to the present disclosure, viewed from one side in the axial direction. This is a front view of the first rotor core sheet of the first embodiment according to the present disclosure, viewed from one side in the axial direction. This is a diagram for explaining the positional relationship between the first magnet hole, the second magnet hole and the opening of the first embodiment according to the present disclosure. This is a diagram for explaining the resin filling process and cooling process for the first magnet hole and the opening of the first embodiment according to the present disclosure. This is an enlarged cross-sectional view of the area around the first overlapping portion of Figure 6. This is a side view of the rotor of the second embodiment according to the present disclosure. This is a cross-sectional view of the rotor core, the first rotor core sheet and the second rotor core sheet of the second embodiment according to the present disclosure.

[0014] Hereinafter, embodiments for implementing this disclosure (hereinafter referred to as "Embodiments") will be described in detail with reference to the attached drawings. Throughout the description of the embodiments, the same elements are denoted by the same numbers or reference numerals.

[0015] Furthermore, the dimensional ratios in the drawings differ from the actual dimensional ratios and are merely for illustrative purposes to make the explanation easier to understand; there is no guarantee that identical parts are depicted with the same dimensions across different drawings.

[0016] Furthermore, for the sake of readability, in drawings, only some of the parts with the same attribute that exist in multiple locations may be assigned reference numerals.

[0017] <<First Embodiment>> The rotor R of the first embodiment according to this disclosure will be described with reference to Figures 1 to 7.

[0018] Figure 1 is a side view of the rotor R of the first embodiment according to the present disclosure, and is a view of the rotor shaft S in the longitudinal direction (Z direction) as seen from the front.

[0019] Figure 2 is a front view of the rotor R of the first embodiment according to this disclosure, viewed from one side in the axial direction. Note that the first rotor core sheet 20, which is provided on one end face of the rotor core 10, is not shown in Figure 2.

[0020] Figure 3 is a front view of the rotor core 10 of the first embodiment according to this disclosure, viewed from one side in the axial direction.

[0021] Figure 4 is a front view of the first rotor core sheet 20 of the first embodiment according to the present disclosure, viewed from one side in the axial direction. In Figure 4, the positions of the first magnet MG1 and the second magnet MG2, which are located on the back side (other side) of the first rotor core sheet 20, are also shown so that their positional relationship with the first magnet MG1 and the second magnet MG2 can be seen.

[0022] In the following, the longitudinal direction (Z direction) of the rotor shaft S, which serves as the axis of rotation, will be referred to as the axial direction, the direction along the rotational direction of the rotor shaft S will be referred to as the circumferential direction, and the direction on the plane perpendicular to the axial direction (XY plane) will be referred to as the radial direction.

[0023] Furthermore, in the radial direction, the side away from the rotor shaft S is described as the radially outer side, and conversely, the side closer to the rotor shaft S is described as the radially inner side.

[0024] For example, Rotor R can be suitably used in motors (also called rotating electric machines) used in hybrid vehicles, electric vehicles, etc.

[0025] Specifically, the motor (not shown) comprises a rotor R of the first embodiment (see Figure 1), a stator (not shown) provided radially outside the rotor R and surrounding the rotor core RCP, and a case (not shown) that houses the rotor R and the stator, and also houses a refrigerant (for example, an oil such as ATF) for cooling the rotor R and the stator.

[0026] In other words, the rotor R of the first embodiment is a rotor R used in an inner rotor type motor (not shown).

[0027] As shown in Figure 1, the rotor R comprises a rotor shaft S and an annular rotor core portion RCP provided on the outer circumference of the rotor shaft S.

[0028] Furthermore, as shown in Figure 2, the rotor R is equipped with magnets (first magnet MG1 and second magnet MG2) provided for each magnetic pole (region between adjacent q axes).

[0029] [Rotor Shaft S] As shown in Figure 2, the rotor shaft S of the first embodiment is a hollow cylindrical member, and a coolant can be flowed through the rotor shaft S. However, the rotor shaft S may also be a non-hollow cylindrical member.

[0030] [Rotor Core Section RCP] As shown in Figure 1, the rotor core section RCP comprises a rotor core 10 and a pair of first rotor core seats 20 provided at both ends of the rotor core 10 in the axial direction (Z direction).

[0031] (Rotor Core 10) In the first embodiment, as shown in Figure 1, the rotor core 10 is formed by stacking a plurality of electromagnetic steel sheets in the axial direction (Z direction), but the rotor core 10 may also be a compacted core made by press-forming metal powder or the like.

[0032] As shown in Figure 3, the rotor core 10 is a cylindrical member having a circular through-hole SH in the center through which the rotor shaft S is positioned.

[0033] The rotor core 10 has a plurality of first magnet holes 11 for housing the first magnet MG1 (see Figure 2) and a plurality of second magnet holes 12 for housing the second magnet MG2 (see Figure 2).

[0034] In the first embodiment, four first magnet holes 11 are provided for each magnetic pole (the region between adjacent q axes).

[0035] Specifically, four first magnet holes 11 are provided for each magnetic pole (in the region between adjacent q axes): a pair of first outer magnet holes 11A arranged symmetrically on the radially outward side with the d axis in between to accommodate the first magnet MG1 (see Figure 2), and a pair of first inner magnet holes 11B arranged symmetrically on the radially inward side with the d axis in between to accommodate the first magnet MG1.

[0036] The first magnet hole 11 (first outer magnet hole 11A and first inner magnet hole 11B) has a placement area S1 in which the first magnet MG1 (see Figure 2) is placed, and a first area S2 adjacent to the placement area S1 that does not house the first magnet MG1.

[0037] The first region S2 is provided adjacent to the arrangement region S1 where the first magnet MG1 (see Figure 2) is placed, in a direction perpendicular to the orientation direction of the first magnet MG1 to be placed.

[0038] In the first embodiment, the pair of first outer magnet holes 11A are arranged to form a V-shape in which the arrangement region S1 for arranging the first magnet MG1 (see Figure 2) opens radially outward.

[0039] However, the design is not limited to this, and the pair of first outer magnet holes 11A may also be arranged such that the arrangement region S1 for positioning the first magnet MG1 is provided in a straight line along a direction perpendicular to the d-axis.

[0040] Furthermore, in the first embodiment, the pair of first inner magnet holes 11B are arranged to form a V-shape in which the arrangement region S1 for arranging the first magnet MG1 (see Figure 2) opens radially inward.

[0041] However, the present invention is not necessarily limited thereto, and the pair of first inner magnet holes 11B may have a linearly arranged arrangement region S1 in which the first magnet MG1 is arranged along a direction orthogonal to the d-axis.

[0042] Note that either one of the pair of first outer magnet holes 11A or the pair of first inner magnet holes 11B may be omitted, such that two first magnet holes 11 are provided for each magnetic pole (a region between adjacent q-axes).

[0043] On the other hand, in the first embodiment, two second magnet holes 12 are provided for each magnetic pole (a region between adjacent q-axes).

[0044] Specifically, for each magnetic pole (a region between adjacent q-axes), a pair of second magnet holes 12 symmetrically arranged on the outer side in the circumferential direction of the first magnet holes 11 with the d-axis interposed therebetween is provided for each magnetic pole.

[0045] The second magnet hole 12 includes an arrangement region S3 where the second magnet MG2 (see FIG. 2) is arranged, and a second region S4 that is provided adjacent to the arrangement region S3 and does not accommodate the second magnet MG2.

[0046] Note that the second region S4 is provided adjacent to the arrangement region S3 where the second magnet MG2 (see FIG. 2) is arranged, on a side in a direction orthogonal to the orientation direction of the arranged second magnet MG2.

[0047] Furthermore, in the first embodiment, the pair of second magnet holes 12 are provided such that the arrangement region S3 where the second magnet MG2 (see FIG. 2) is arranged forms a V-shape opening outward in the radial direction.

[0048] (First rotor core sheet 20) The first rotor core sheets 20 are provided at both axial end portions of the rotor core 10, and the first rotor core sheet 20 provided on at least one axial side (Z-direction side) of the rotor core 10 is in contact with axial end surfaces on one side of the first magnet MG1 and the second magnet MG2.

[0049] Alternatively, the first rotor core sheet 20 provided on one side of the rotor core 10 in the axial direction (Z direction) may contact one axial end face of the first magnet MG1 and the second magnet MG2, while the first rotor core sheet 20 provided on the other side of the rotor core 10 in the axial direction (Z direction) may contact the other axial end face of the first magnet MG1 and the second magnet MG2.

[0050] Furthermore, the first rotor core seat 20, which is provided on the other side of the rotor core 10 in the axial direction (Z direction), may be omitted.

[0051] As shown in Figure 4, the first rotor core sheet 20 is a disc-shaped member having a circular opening SO in the center through which the rotor shaft S passes. The first rotor core sheet 20 is made of materials such as electromagnetic steel.

[0052] The first rotor core sheet 20 is provided corresponding to each first magnet hole 11 (see Figure 3) and has a plurality of openings 21 that partially overlap the corresponding first magnet MG1. In other words, the first rotor core sheet 20 is provided corresponding to the first magnet hole 11 and has openings 21 that partially overlap the arrangement region S1 in which the first magnet MG1 of the first magnet hole 11 is arranged.

[0053] As will be explained later, in the first embodiment, when viewed in a cross-section perpendicular to the longitudinal direction of the first magnet MG1, the short side direction is the orientation direction, and the long side direction is perpendicular to the orientation direction.

[0054] Therefore, as can be seen in Figure 4, the opening 21 is provided on the first rotor core sheet 20 so as not to overlap with the side MS of the first magnet MG1 (the short side of the axial end face of the first magnet MG1) on the side perpendicular to the orientation direction of the first magnet MG1.

[0055] In other words, the opening 21 is not positioned to overlap with the side MS of the first magnet MG1 (in this example, the short side of the axial end face of the first magnet MG1) along the orientation direction of the first magnet MG1.

[0056] In the first embodiment, an opening 21 is provided corresponding to each of the first magnet holes 11 (see Figure 3) that house the first magnet MG1, and the first rotor core sheet 20 has four openings 21 for each magnetic pole (region between adjacent q axes).

[0057] Specifically, four openings 21 are provided for each magnetic pole (in the region between adjacent q axes): a pair of outer openings 21A corresponding to a pair of first outer magnetic holes 11A (see Figure 3) which are provided radially outward and symmetrically on the d axis, and a pair of inner openings 21B corresponding to a pair of first inner magnetic holes 11B (see Figure 3) which are provided radially inward and symmetrically on the d axis, and these four openings 21 are provided for each magnetic pole (in the region between adjacent q axes).

[0058] (First magnet MG1 and second magnet MG2) The first magnet MG1 and the second magnet MG2 both use the same magnet, and in the first embodiment, the first magnet MG1 and the second magnet MG2 are neodymium magnets (Nd magnets) in which the crystal easy magnetization axis is oriented in one direction.

[0059] Furthermore, anisotropic magnets other than neodymium magnets may be used for the first magnet MG1 and the second magnet MG2. Also, the shapes of the first magnet MG1 and the second magnet MG2 may be different.

[0060] In the first embodiment, when viewed in a cross-section perpendicular to the longitudinal direction, the first magnet MG1 and the second magnet MG2 have their orientation direction in the short side direction and their orientation direction in the long side direction perpendicular to the orientation direction.

[0061] Therefore, during the cooling process after filling the first magnet hole 11 (see Figure 3) and the second magnet hole 12 (see Figure 3), which will be explained later, with resin, the first magnet MG1 and the second magnet MG2 contract in the direction of the shorter side, which is the orientation direction, and expand in the direction of the longer side, which is perpendicular to the orientation direction.

[0062] Depending on the design of the rotor R, a first magnet MG1 and a second magnet MG2 may be used in which the longer side is the orientation direction and the shorter side is perpendicular to the orientation direction.

[0063] Next, with reference to Figure 5, the positional relationship between the first magnet hole 11 (see Figure 3), the second magnet hole 12 (see Figure 3), and the opening 21 will be explained in detail.

[0064] Figure 5 is a diagram illustrating the positional relationship between the first magnet hole 11, the second magnet hole 12, and the opening 21 in the first embodiment of the present disclosure. It is an enlarged view of the area including the first magnet hole 11, the second magnet hole 12, and the opening 21, which are located within one magnetic pole (the region between adjacent q axes) when the rotor core RCP is viewed from one side.

[0065] Note that the first magnet hole 11, the second magnet hole 12, and the magnets (first magnet MG1 and second magnet MG2) are located towards the back of the paper and are not normally visible, but in Figure 5 they are depicted in a way that makes their state clear.

[0066] As shown in Figure 5, the opening 21 of the first rotor core sheet 20 has a first overlapping portion 22 that overlaps the first region S2 of the first magnet hole 11 that does not contain the first magnet MG1.

[0067] Specifically, the opening 21, which has a portion that overlaps with the arrangement area S1 in which the first magnet MG1 of the first magnet hole 11 is placed, also has a first overlapping portion 22 that overlaps with the first area S2 in which the first magnet MG1 of the first magnet hole 11 is not housed.

[0068] In other words, the opening 21 has a portion that overlaps with a part of the arrangement area S1 with respect to the corresponding first magnet hole 11, and a first overlapping portion 22 that overlaps with the first area S2.

[0069] The first overlapping portion 22 is provided in the orientation direction of the first magnet MG1 which is housed in the corresponding first magnet hole 11 (the first magnet hole 11 whose opening 21 overlaps the arrangement region S1).

[0070] More specifically, the first overlapping portion 22 is positioned further away from the first magnet MG1 in the orientation direction (the direction of the short side of the first magnet MG1) than the first magnet MG1 housed in the corresponding first magnet hole 11.

[0071] Furthermore, the position where the first overlapping portion 22 is provided is also a position further away from the first magnet MG1 in a direction perpendicular to the orientation direction (the direction of the long side of the first magnet MG1) than the first magnet MG1 housed in the corresponding first magnet hole 11.

[0072] Figure 6 is a diagram illustrating the resin filling process and cooling process for the first magnet hole 11 and the opening 21 according to the first embodiment of the present disclosure. Figure 6 is a cross-sectional view taken along line A-A in Figure 5, with the left side of Figure 6 being side A1 and the right side being side A2.

[0073] As shown in Figure 6, before the other side's first rotor core sheet 20 is installed, the outer end face of one side's first rotor core sheet 20 is placed in close contact with the mounting section MP of the resin filling device, and resin is supplied to the first magnet hole 11 from the other side.

[0074] The supplied resin then flows into the opening 21 through the first overlapping portion 22, filling the opening 21 with resin. This filled resin solidifies during the cooling process, becoming the resin portion RP located between the first magnet MG1 and the first magnet hole 11, and within the opening 21.

[0075] Although the portion of the opening 21 that overlaps the first magnet MG1 appears not to be connected to the first overlapping portion 22 in the cross-sectional view shown in Figure 6, as shown in Figure 5, it is connected to the first overlapping portion 22 in a portion not shown in the cross-sectional view of Figure 6, and is filled with resin flowing into the opening 21 from the first overlapping portion 22.

[0076] Furthermore, the upper and lower edges of the first magnet MG1 shown in Figure 6 are the longer sides of the longitudinal end faces of the first magnet MG1 (the sides perpendicular to the orientation direction of the first magnet MG1), and as explained earlier, they have a negative coefficient of linear expansion. On the other hand, the resin has a positive coefficient of linear expansion.

[0077] Therefore, during the cooling process after the filling process, the first magnet MG1 expands in the left-right direction in Figure 6, as indicated by the thick black arrows. On the other hand, the resin attempts to contract, as indicated by the dotted arrows.

[0078] As a result of this expansion and contraction, stress tends to concentrate in the portion P (the other side portion P1 and the one side portion P2) of the side MS (in this example, the short side of the longitudinal end face of the first magnet MG1) along the orientation direction of the first magnet MG1.

[0079] However, since the resin on the other side is in a free state, it flows in response to the stress that would otherwise concentrate on the other side portion P1, thus avoiding stress concentration and preventing the occurrence of cracks and the like.

[0080] On the other hand, the one-sided portion P2 does not have an opening 21 and is only in contact with the first rotor core sheet 20, so there is no resin itself that can cause cracks, and therefore there is no risk of cracks occurring.

[0081] Furthermore, if the other first rotor core sheet 20 (not shown) is also made to contact the axial end face of the first magnet MG1, and resin is supplied to the opening 21 (not shown) of the other first rotor core sheet 20, and the resin is filled from the opening 21 of the other first rotor core sheet 20 to the first magnet hole 11 and the opening 21 of the first rotor core sheet 20 on one side, then the other first rotor core sheet 20 will be in the same condition as the first first rotor core sheet 20 on one side shown in Figure 6, and there will be no risk of cracks occurring.

[0082] Thus, the rotor R of the first embodiment suppresses the occurrence of cracks in the resin on the end face of the first magnet MG1.

[0083] Furthermore, as explained earlier, the first overlapping portion 22 is provided in the orientation direction of the first magnet MG1 housed in the corresponding first magnet hole 11 (the first magnet hole 11 whose opening 21 overlaps the arrangement region S1), so it is not affected by the expansion of the first magnet MG1 during the cooling process, and there is no risk of cracks occurring.

[0084] By the way, in the first embodiment, as explained earlier, a portion of the opening 21 overlaps with the arrangement region S1 in which the first magnet MG1 of the first magnet hole 11 is placed. As shown in Figure 6, resin is provided on one axial end face of the first magnet MG1.

[0085] Therefore, the formation of magnetic paths is suppressed, and leakage flux is reduced, resulting in improved electromagnetic performance.

[0086] Figure 7 is an enlarged cross-sectional view showing the area around the first overlapping portion 22 in Figure 6. As shown in Figure 7, the first overlapping portion 22 has an opening area OS1 when viewed from the first region S2 side to the first overlapping portion 22 side, which is defined by the opening width W1 at the boundary between the first region S2 and the opening 21 and the depth width D1 along the first overlapping portion 22 (in the front-to-back direction of the paper in Figure 7).

[0087] Similarly, the first overlapping portion 22 has an opening area OS2 when viewed from the opening 21 side to the first overlapping portion 22 side, which is defined by the opening width W2 corresponding to the thickness of the opening 21 and the depth width D2 along the first overlapping portion 22 (in the front-to-back direction of the paper in Figure 7).

[0088] In the first embodiment, the opening area OS2 of the first overlapping portion 22 is larger when viewed from the opening 21 side to the first overlapping portion 22 side than when viewed from the first region S2 side to the first overlapping portion 22 side.

[0089] In this way, if the opening area OS2 has a larger area than the opening area OS1, the resin flowing from the first region S2 through the first overlapping portion 22 into the opening 21 will flow toward the side with the larger opening area. This suppresses obstruction of the resin flow and enables good resin filling into the opening 21.

[0090] Therefore, it is possible to thoroughly fill the resin up to the opening 21 and other locations on the first magnet MG1 shown in Figure 6, thereby suppressing the occurrence of areas that are not filled with resin and preventing the first magnet MG1 from being exposed to the outside air.

[0091] On the other hand, as shown in Figure 5, the opening 21 of the first rotor core sheet 20 has a second overlapping portion 23 that overlaps the second region S4 of the second magnet hole 12 that does not house the second magnet MG2.

[0092] Specifically, a pair of inner openings 21B corresponding to a pair of first inner magnet holes 11B among the openings 21 are provided with a second overlapping portion 23.

[0093] The second overlapping portion 23 is provided in the orientation direction of the second magnet MG2, which is housed in the corresponding second magnet hole 12 (the second magnet hole 12 in which the opening 21 overlaps with the second overlapping portion 23).

[0094] More specifically, the second overlapping portion 23 is positioned further away from the second magnet MG2 in the orientation direction (the direction of the short side of the second magnet MG2) than the second magnet MG2 housed in the corresponding second magnet hole 12.

[0095] Furthermore, the position where the second overlapping portion 23 is provided is also a position away from the second magnet MG2 in a direction perpendicular to the orientation direction (the direction of the long side of the second magnet MG2) than the second magnet MG2 housed in the corresponding second magnet hole 12.

[0096] Thus, the positional relationship of the second overlapping portion 23 with respect to the second magnet MG2 is the same as the positional relationship of the first magnet MG1 with respect to the first magnet MG1, as explained earlier. Since it is positioned in the orientation direction of the second magnet MG2 housed in the corresponding second magnet hole 12 (the second magnet hole 12 whose opening 21 overlaps with the second overlapping portion 23), it is not affected by the expansion of the second magnet MG2 during the cooling process, and there is no risk of cracks occurring.

[0097] By the way, in the first embodiment, the resin filling process is carried out by supplying resin to the first magnet hole 11 from the other side, as explained earlier.

[0098] As can be seen in Figure 5, the resin supplied to the first magnet hole 11 flows from the first magnet hole 11 through the first overlapping portion 22 into the opening 21, and then the resin flows through the opening 21 toward the second overlapping portion 23, and through the second overlapping portion 23 into the second magnet hole 12, thereby filling the opening with resin. The resin that has been filled in this way solidifies during the cooling process and becomes a resin portion RP (not shown) provided between the second magnet MG2 and the second magnet hole 12.

[0099] However, the resin filling process does not need to be limited to supplying resin to the first magnet hole 11 from the other side; resin may also be supplied from the other side of the second magnet hole 12.

[0100] In such cases, it is preferable to improve the fluidity of the resin in the second overlapping portion 23 as well, similar to the first overlapping portion 22, by making the opening area of ​​the second overlapping portion 23 larger when viewed from the opening 21 side to the second overlapping portion 23 side than when viewed from the second region S4 side to the second overlapping portion 23 side.

[0101] <<Second Embodiment>> Next, the rotor R of the second embodiment according to this disclosure will be described with reference to Figures 8 and 9.

[0102] The rotor R of the second embodiment has the same basic configuration as the rotor R of the first embodiment. Below, we will mainly describe the differences from the first embodiment, and we may omit explanations of the similarities.

[0103] Figure 8 is a side view of the rotor R of the second embodiment according to the present disclosure, and corresponds to Figure 1.

[0104] As shown in Figure 8, the rotor R of the second embodiment further comprises a rotor core RCP which includes a pair of second rotor core sheets 30 provided at the ends of the first rotor core sheet 20.

[0105] Furthermore, the second rotor core sheet 30 has the same structural substance as the first rotor core sheet 20. Therefore, to put it another way, the rotor R of the second embodiment can be said to be equipped with a plurality of first rotor core sheets 20, each provided at the axial (Z-direction) end of the rotor core 10.

[0106] Figure 9 is a cross-sectional view of the rotor core 10, the first rotor core sheet 20, and the second rotor core sheet 30 of the second embodiment according to the present disclosure, and is a cross-sectional view at the position corresponding to the line B-B in Figure 6.

[0107] As explained earlier, the first rotor core sheet 20 and the second rotor core sheet 30 are of the same design, so the second rotor core sheet 30 has an opening 31 that has the same shape as the opening 21 of the first rotor core sheet 20.

[0108] On the other hand, the second rotor core sheet 30 is superimposed on the first rotor core sheet 20, slightly offset in the circumferential direction, such that the opening 31 of the second rotor core sheet 20 is slightly misaligned and overlaps with the opening 21 of the first rotor core sheet 20.

[0109] Furthermore, during the cooling process, the first magnet MG1 attempts to expand in its longitudinal direction (see Z direction). However, the stress during this expansion is borne not only by the resin in the opening 21 but also by the resin in the opening 31. As a result, the stress is distributed, and the occurrence of cracks in the resin in the opening 21 at the position overlapping with the first magnet MG1 is suppressed.

[0110] Although the above description has been based on specific embodiments, this disclosure is not limited to the embodiments described above. This disclosure also includes modifications and improvements to the embodiments, which will be clear to those skilled in the art from the claims.

[0111] 10...Rotor core, 11...First magnet hole, 12...Second magnet hole, 20...First rotor core sheet, 21...Opening, 22...First overlapping section, 23...Second overlapping section, MG1...First magnet, MG2...Second magnet, MS...Side section, OS1, OS2...Opening area, R...Rotor, RP...Resin section, S1, S3...Placement area, S2...First area, S4...Second area

Claims

1. A rotor comprising: a rotor core having a first magnet hole for housing a first magnet; a first rotor core sheet having an opening that contacts the axial end face of the first magnet and partially overlaps the arrangement area of ​​the first magnet hole where the first magnet is placed; and a resin portion provided between the first magnet and the first magnet hole, and within the opening, wherein the opening is not provided in a position that overlaps the side of the first magnet along the orientation direction of the first magnet.

2. The rotor according to claim 1, wherein the first magnet hole has a first region that does not house the first magnet and is provided adjacent to the arrangement region where the first magnet is arranged, the opening has a first overlapping portion that overlaps the first region, and the first overlapping portion is provided in the orientation direction of the first magnet.

3. The rotor according to claim 2, wherein the rotor core has a second magnet hole for housing a second magnet, the rotor comprises a resin portion provided between the second magnet and the second magnet hole, the second magnet hole has a second region provided adjacent to the arrangement region for arranging the second magnet and not housing the second magnet, the opening comprises a second overlapping portion that overlaps the second region, and the second overlapping portion is provided in the orientation direction of the second magnet.

4. The rotor according to claim 3, wherein the first overlapping portion has a larger opening area when viewed from the opening side towards the first overlapping portion than when viewed from the first region side towards the first overlapping portion, and the second overlapping portion has a larger opening area when viewed from the opening side towards the second overlapping portion than when viewed from the second region side towards the second overlapping portion.

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