Rotor, traction motor and manufacturing method of a rotor

Abstract

A rotor rotates around a rotation axis. The rotor includes: a core laminate configured by laminating a plurality of core blocks in an axial direction of the rotation axis, the core blocks each being configured by laminating a plurality of steel sheets in the axial direction and having a plurality of insertion holes arranged in a circumferential direction; a plurality of magnets located inside the plurality of insertion holes; and a plurality of resin members that fix the magnets to the inside of the plurality of insertion holes. Axially adjacent core blocks are located at positions that are angularly offset from each other around the rotation axis. The insertion holes of the axially adjacent core blocks communicate with each other in the axial direction. The resin members include: a filling portion located inside the insertion hole; a first gate portion located on one axial side in the filling portion; and a second gate portion located on the other axial side in the filling portion.

Description

TECHNICAL FIELD

[0001] The present application relates to a rotor. This application claims priority from Japanese Patent Application No. 2019-179309 filed on September 30, 2019, and the contents are hereby incorporated by reference. BACKGROUND

[0002] Japanese Patent Application Publication No. 2018-7483 describes a rotor core configured by stacking a plurality of electromagnetic steel sheets in an axial direction, and embedded with a plurality of permanent magnets. The rotor core has a layered skew structure in which the positions of the permanent magnets are staggered in the circumferential direction in segments in the axial direction.

[0003] In order to manufacture a layered skew rotor core, in Japanese Patent Application Publication No. 2018-7483, an injection process of injecting an adhesive into a magnet insertion hole of a first layer, an insertion process of inserting a permanent magnet into the magnet insertion hole, and a filling process of filling the adhesive in the magnet insertion hole are sequentially performed. Then, after a stacking process of stacking a plurality of electromagnetic steel sheets of a second layer with respect to the first layer at a prescribed skew angle and staggering in the circumferential direction is performed, the injection process, the insertion process, and the filling process are performed on the magnet insertion hole of the second layer. It is considered that by the above manufacturing method, a wider range of the outer surface of the permanent magnet can be covered with the adhesive, and thus the stress acting on the permanent magnet when the rotor core is rotated at high speed can be alleviated.

[0004] Patent Literature 1: Japanese Patent Application Publication No. 2018-7483 SUMMARY

[0005] PROBLEMS TO BE SOLVED BY THE INVENTION

[0006] However, in the above-described prior art, the injection and filling of the adhesive are performed for each layer, and thus the number of work processes increases. Therefore, there is a problem that the productivity of the rotor decreases.

[0007] An object of the present application is to provide a technology that improves the production efficiency of a rotor having a skew structure.

[0008] TECHNICAL SOLUTION

[0009] To solve the above-described technical problem, a rotor of a first mode rotates around a rotation axis, and includes: a core laminate constituted by laminating a plurality of core blocks in an axial direction of the rotation axis, the core blocks being constituted by a plurality of steel sheets laminated in the axial direction and having a plurality of insertion holes arranged in a circumferential direction; a plurality of magnets located inside the plurality of insertion holes; and a plurality of resin members that fix the magnets to the inside of the plurality of insertion holes, the core blocks adjacent in the axial direction being located at positions that are angularly offset from each other around the rotation axis, the insertion holes of the core blocks adjacent in the axial direction being in communication with each other in the axial direction, the resin members including: a filled portion located inside the insertion hole; a first gate portion located on one axial side in the filled portion; and a second gate portion located on the other axial side in the filled portion.

[0010] Effects of Invention

[0011] According to the rotor of the above-described structure, by filling the resin in the insertion holes that are in communication with each other at one time, the number of work processes can be reduced compared to a case where the resin is filled for each core block. Also, when injecting the resin in a flow state into the insertion hole via the flow inlet of the mold corresponding to the first gate portion, even if the resin moves locally offset in the insertion hole, the resin that moves first can be caused to flow out of the insertion hole of the core block on the other axial side via the flow outlet of the mold corresponding to the second gate portion. Thus, the resin in a flow state can be caused to spread throughout the inside of the insertion hole, and thus resin filling failure in the insertion hole can be suppressed. Therefore, the productivity of the rotor can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a perspective view of a rotor of a first embodiment.

[0013] Figure 2 is a perspective view of an axial one side of a resin member of the first embodiment.

[0014] Figure 3 is a perspective view of an axial other side of the resin member of the first embodiment.

[0015] Figure 4 is a flowchart showing an example of a manufacturing method of the rotor of the first embodiment.

[0016] Figure 5 is a perspective view of a mold of the first embodiment.

[0017] Figure 6 is a longitudinal sectional view of a traction motor of a second embodiment.

[0018] Figure 7is a perspective view of the axial one side of the rotor of the second embodiment.

[0019] Figure 8 is a perspective view of the axial other side of the rotor of the second embodiment.

[0020] Figure 9 is a perspective view of the axial one side of the core stack of the second embodiment.

[0021] Figure 10 is a perspective view of the axial other side of the core stack of the second embodiment.

[0022] Figure 11 is a plan view of the first core block of the axial one side.

[0023] Figure 12 is a plan view of the first end plate of the axial one side.

[0024] Figure 13 is a plan view of the second end plate of the axial other side.

[0025] Figure 14 is a perspective view of the resin member of the second embodiment.

[0026] Figure 15 is a flowchart of the manufacturing method of the rotor of the second embodiment.

[0027] Figure 16 is a perspective view of an example of the mold.

[0028] Figure 17 is a view showing the inner surface of the other side mold.

[0029] Figure 18 is a view showing the resin member formed in the mold. DETAILED DESCRIPTION

[0030] Hereinafter, an embodiment of the present application will be described with reference to the drawings. Note that the constituent elements described in the present embodiment are merely examples, and the scope of the present application is not intended to be limited to these constituent elements. In the drawings, the size, the number, and the like of each part are sometimes exaggerated or simplified as necessary for convenience of understanding.

[0031] Hereinafter, the direction parallel to the rotational axis of the rotor will be referred to as the "axial direction", the direction orthogonal to the axial direction will be referred to as the "radial direction", and the direction along the circular arc centered on the rotational axis will be referred to as the "circumferential direction". The direction in the radial direction close to the rotational axis will be set as the inner side in the radial direction, and the direction away from the rotational axis will be set as the outer side in the radial direction.

[0032] <1. First Embodiment>

[0033] Figure 1 is a perspective view of the rotor 3A of the first embodiment. The rotor 3A rotates about the rotational axis 9A. The rotor 3A includes a core laminate 40A. The core laminate 40A is configured by axially laminating a plurality of first core pieces 41A and a plurality of second core pieces 42A. Each of the core pieces 41A, 42A is configured by laminating a plurality of steel sheets. In the core laminate 40A, the first core pieces 41A are located at one axial end, and the second core pieces 42A are located at the other axial end.

[0034] The first core piece 41A has a plurality of insertion holes 43A arranged in the circumferential direction. Similarly to the first core piece 41A, the second core piece 42A also has a plurality of insertion holes 43B arranged in the circumferential direction. The magnets 60A are located inside the respective insertion holes 43A, 43B. The magnets 60A are fixed to the inside of the insertion holes 43A, 43B by a resin member 70A.

[0035] The core pieces 41A, 42A are axially adjacent to each other and are located at positions that are angularly offset from each other about the rotational axis 9A. That is, the core laminate 40A has a skew structure. The insertion holes 43A, 43B are axially continuous with each other. "Continuous" here refers to a state of being connected in a manner in which fluid can flow.

[0036] Figure 2 is a perspective view of the axial one side of the resin member 70A of the first embodiment. Figure 3 is a perspective view of the axial other side of the resin member 70A of the first embodiment. As Figure 2 and Figure 3 shown, the resin member 70A has a filled portion 71A located in the insertion holes 43A, 43B, a first gate portion 73A located on the axial one side of the filled portion 71A, and a second gate portion 75A located on the axial other side of the filled portion 71A.

[0037] <Manufacturing Method of Rotor 3A>

[0038] Figure 4 is a flowchart showing an example of the manufacturing method of the rotor 3A of the first embodiment. To manufacture the rotor 3A, first, a preparation process S1A of preparing the core laminate 40A is performed. In the preparation process S1A, a plurality of steel sheets are laminated, thereby producing the core pieces 41A, 42A. Also, the first core pieces 41A are laminated in the circumferential direction with respect to the second core pieces 42A on the axial one side of the second core pieces 42A about the rotational axis 9A. Also, the magnets 60A are inserted into the respective insertion holes 43A, 43B of the core pieces 41A, 42A. After the core laminate 40A is prepared by the preparation process S1A, a placement process S2A of placing the core laminate 40A in a mold 80A is performed.

[0039] Figure 5is a perspective view showing the mold 80A of the first embodiment. As shown in Figure 5 The mold 80 has one side mold 81A and the other side mold 82A. The one side mold 81A and the other side mold 82A have inner surfaces that are concave in shape corresponding to the outer shape of the core stack 40A. The one side mold 81A is provided with a plurality of (eight in this example) injection ports 83A. Each of the injection ports 83A communicates with the insertion hole 43A of the first core piece 41A. The inner surface of the other side mold 82A is provided with a plurality of (eight in this example) flow outlets 851A that are concave in shape, which communicate with a resin accumulation portion 85A provided inside the other side mold 82A. When the core stack 40A is disposed inside the mold 80A, each of the flow outlets 851A communicates with the insertion hole 43B of the second core piece 42A.

[0040] Returning to Figure 4 After the disposing process S2A, an injecting process S3A is performed. In the injecting process S3A, the resin in a flow state is injected into the mold 80A through the injection ports 83A. Figure 5 The injection ports 83A of the mold 80A shown in the drawing inject the resin into each of the insertion holes 43A and each of the insertion holes 43B that communicate with each of the insertion holes 43A.

[0041] Next, a filling process S4A is performed. In the filling process S4A, the resin in a flow state that is injected into the mold 80A through the injecting process S3A is caused to flow out from the insertion holes 43B to the resin accumulation portion 85A through the flow outlets 851A while filling the insertion holes 43A, 43B.

[0042] The resin filled in the insertion holes 43A, 43B through the filling process S4A is cured, thereby forming the resin member 70A. The first gate portion 73A in the resin member 70A is part of a convex portion formed by flowing into the insertion holes 43A from the injection ports 83A. Also, the second gate portion 75A is part of a convex portion formed by flowing out of the resin to the flow outlets 851A and the resin accumulation portion 85A.

[0043] According to the structure and the manufacturing method of the rotor 3A described above, the resin can be filled in the insertion holes 43A, 43B that communicate in the axial direction at one time, so the number of processes can be reduced compared to the case where the resin is filled for each of the core pieces 41A, 42A. Also, when the resin in a flow state is injected from the injection ports 83A of the mold 80A, even if the resin moves locally shifted in the insertion holes 43A, 43B, the resin that moves first can be caused to flow out from the insertion holes 43B to the resin accumulation portion 85A through the flow outlets 851A. Thus, the resin in a flow state can be caused to spread throughout the inside of each of the insertion holes 43A, 43B, so resin filling failure in the insertion holes 43A, 43B can be suppressed. Therefore, the productivity of the rotor 3A can be improved. Also, the position of the magnet 60A in the insertion holes 43A, 43B can be stabilized.

[0044] <2. Second Embodiment>

[0045] Figure 6 is a longitudinal sectional view of a traction motor 1 of a second embodiment. The traction motor 1 is, for example, a device that is installed in a vehicle such as an electric vehicle, a plug-in hybrid vehicle, and the like, and outputs a driving force for running of the vehicle. The traction motor 1 includes a motor 11, a gear 13, and an inverter 15. The motor 11 has a stator 2 and a rotor 3. The stator 2 supports the rotor 3 so as to be rotatable. The gear 13 is connected to the motor 11. The inverter 15 is electrically connected to the motor 11. The inverter 15 is a device that converts direct current into alternating current, and supplies a driving current obtained by the conversion to the motor 11.

[0046] The stator 2 has a housing 21, a cover portion 22, a stator 23, a first bearing portion 24, and a second bearing portion 25. The housing 21 is a substantially cylindrical frame that houses the stator 23, the first bearing portion 24, the rotor 3, and a shaft 30 inside. A recess 211 for holding the first bearing portion 24 is provided in the center of the bottom of the housing 21. The cover portion 22 is a plate-like member that closes the opening of the axial side of the housing 21. A circular hole 221 for holding the second bearing portion 25 is provided in the center of the cover portion 22.

[0047] The stator 23 generates a magnetic flux in accordance with a driving current. The stator 23 has a stator core 26 and a coil 27. The stator core 26 is composed of a plurality of steel sheets that are stacked in the axial direction. The stator core 26 has a circular ring-shaped core back 261, and a plurality of pole tooth portions 262 that protrude toward the inner side in the radial direction from the core back 261. The core back 261 is fixed to the inner peripheral surface of the side wall of the housing 21. The coil 27 is composed of a wire that is wound around each of the pole tooth portions 262 of the stator core 26.

[0048] The first bearing portion 24 and the second bearing portion 25 are mechanisms that support the shaft 30 connected to the through hole 3H of the rotor 3 so as to be rotatable. The first bearing portion 24 and the second bearing portion 25 of the present embodiment use a ball bearing that relatively rotates an outer ring and an inner ring via a ball. However, as an alternative to the ball bearing, other types of bearings such as a slide bearing, a fluid bearing, or the like can be used.

[0049] The outer ring 241 of the first bearing portion 24 is fixed to the recess 211 of the housing 21. Also, the outer ring 251 of the second bearing portion 25 is fixed to the rim portion of the circular hole 221 of the cover portion 22. On the other hand, the inner rings 242, 252 of the first bearing portion 24 and the second bearing portion 25 are fixed to the shaft 30. Therefore, the shaft 30 is supported so as to be rotatable with respect to the housing 21 and the cover portion 22.

[0050] The shaft 30 is a substantially cylindrical member extending in the axial direction along the rotation axis 9. The shaft 30 is rotatable about the rotation axis 9 while being supported by the first bearing portion 24 and the second bearing portion 25. Further, the shaft 30 has a head portion 301 protruding toward the axial direction from the cover portion 22. The head portion 301 is connected to a drive target of the vehicle via the gear 13 as a power transmission mechanism. The rotor 3 rotates together with the shaft 30 on the radially inner side of the stator 23. The rotor 3 has a plurality of magnets 60 as described later.

[0051] In the motor 11, when a drive current is applied from the inverter 15 to the coils 27 of the stator 23, the plurality of tooth portions 262 of the stator core 26 generate a radial magnetic flux. Further, a circumferential torque is generated by the action of a magnetic force between the tooth portions 262 and the magnets 60. As a result, the rotor 3 rotates about the rotation axis 9 relative to the stator 23. When the rotor 3 rotates, a rotational drive force is transmitted to the gear 13 connected to the shaft 30.

[0052] Structure of Rotor 3

[0053] Figure 7 Fig. 6 is a perspective view showing the axial one side of the rotor 3 of the second embodiment. Figure 8 Fig. 7 is a perspective view showing the axial other side of the rotor 3 of the second embodiment. Figure 9 Fig. 8 is a perspective view showing the axial one side of the core stack 40 of the second embodiment. Figure 10 Fig. 9 is a perspective view showing the axial other side of the core stack 40 of the second embodiment. Figure 11 Fig. 10 is a plan view showing the first core block 41 of the axial one side. Figure 12 Fig. 11 is a plan view showing the first end plate 51 of the axial one side. Figure 13 Fig. 12 is a plan view showing the second end plate 52 of the axial other side. Figure 14 Fig. 13 is a perspective view showing the resin member 70 of the second embodiment.

[0054] The rotor 3 has the core stack 40, the first end plate 51, the second end plate 52, a plurality of magnets 60, and a plurality of resin members 70. The core stack 40 is configured by stacking two first core blocks 41 and a second core block 42 in the axial direction. The core blocks 41, 42 are each configured by a plurality of substantially circular ring-shaped steel sheets stacked in the axial direction.

[0055] The core blocks 41, 42 have the same shape and size. The core blocks 41, 42 are adjacent in the axial direction and are located at positions circumferentially displaced from each other by an angle about the rotation axis 9. That is, the core stack 40 has a so-called skew structure. The angle (skew angle) by which the second core block 42 is displaced relative to the first core block 41 is, for example, 3.25°.

[0056] The first core block 41 has sixteen insertion holes 43a arranged circumferentially. More specifically, the first core block 41 has eight sets of circumferentially close pairs of insertion holes 43a, 43a at equal intervals. When viewed axially, the pairs of insertion holes 43a, 43a are circumferentially spaced apart and form a V-shape that moves away from each other circumferentially as they move radially outward.

[0057] The second core block 42, like the first core block 41, has sixteen insertion holes 43b arranged circumferentially. More specifically, the second core block 42 has eight sets of circumferentially close pairs of insertion holes 43b, 43b spaced equally apart. The pairs of insertion holes 43b, 43b, are also V-shaped when viewed axially, similar to the pairs of insertion holes 43a, 43a. The insertion holes 43b have the same shape and size as the insertion holes 43a.

[0058] Insertion holes 43a and 43b are through holes with a constant opening shape in the axial direction. Each insertion hole 43a and insertion hole 43b is axially connected. That is, as shown... Figure 7 and Figure 8 As shown, insertion holes 43a and 43b form a continuous continuous hole 43.

[0059] Each insertion hole 43a, 43b is provided with a magnet 60. By arranging a pair of insertion holes 43a, 43a and a pair of insertion holes 43b, 43b in a V-shape, the pair of magnets 60 can be configured in a V-shape. This improves the magnetic characteristics of the rotor 3. Furthermore, the magnets 60 are arranged one by one in the pair of insertion holes 43a, 43a with the same magnetic poles facing outwards. The magnets 60 arranged in the pair of insertion holes 43a, 43a and the circumferentially adjacent pair of insertion holes 43a, 43a are arranged with different magnetic poles facing outwards. The same applies to the pair of insertion holes 43b, 43b. The magnets 60 are fixed to the inside of the insertion holes 43a, 43b by the resin member 70 described later.

[0060] End plates 51 and 52 are identical, roughly circular components. For example... Figure 12 As shown, the first end plate 51 has a plurality of (sixteen in this example) first connecting holes 53 serving as first through holes and a plurality of (eight in this example) third connecting holes 55 serving as second through holes. Figure 13 As shown, the second end plate 52 also has a plurality of fourth connecting holes 56 (sixteen in this example) serving as first through holes and a plurality of second connecting holes 54 (eight in this example) serving as second through holes. In the first end plate 51, a plurality of first connecting holes 53 are located on the same circumference, and a plurality of third connecting holes 55 are located at equal intervals on the same circumference. In the second end plate 52, a plurality of fourth connecting holes 56 are also located on the same circumference, and a plurality of second connecting holes 54 are also located at equal intervals on the same circumference.

[0061] As shown in Figure 7 , the first end plate 51 is located at one axial side of the core stack 40. The first end plate 51 opposes the plurality of magnets 60 arranged in the insertion hole 43a in the axial direction, and prevents the magnets 60 from falling out of the insertion hole 43a toward the one axial side. Also, as shown in Figure 7 and Figure 12 , the first connecting hole 53 of the first end plate 51 communicates with the insertion hole 43a of the first core block 41. By providing the first end plate 51 with the first connecting hole 53, the resin member 70 can be filled from the one axial side of the continuous hole 43 after the first end plate 51 is installed to the core stack 40.

[0062] As shown in Figure 8 , the second end plate 52 is located at the other axial side of the core stack 40. The second end plate 52 opposes the plurality of magnets 60 arranged in the insertion hole 43b in the axial direction, and prevents the magnets 60 from falling out of the insertion hole 43b toward the other axial side. As shown in Figure 8 and Figure 13 , the second connecting hole 54 of the second end plate 52 communicates with the insertion hole 43b of the second core block 42. By providing the second end plate 52 with the second connecting hole 54, the resin member 70 can be caused to flow out from the other axial side of the continuous hole 43 after the second end plate 52 is installed to the core stack 40.

[0063] The core blocks 41, 42 are each provided with a pair of insertion holes 43a, 43a and a pair of insertion holes 43b, 43b that are close in the circumferential direction. Therefore, in the rotor 3, as shown in Figure 14 , a pair of resin members 70 are arranged close in the circumferential direction. The resin member 70 has a filling portion 71, a first gate portion 73, and a second gate portion 75. The filling portion 71 is located inside the insertion holes 43a, 43b (i.e., the continuous hole 43) that communicate in the axial direction. More specifically, the filling portion 71 has a first filling portion 711 located inside the insertion hole 43a and a second filling portion 712 located inside the insertion hole 43b. The first gate portion 73 is located at the one axial side of the filling portion 71. In the present example, the first gate portion 73 is a protruding portion that protrudes from the first end surface 71S at the one axial side of the first filling portion 711 toward the one axial side. As shown in Figure 7 , the first gate portion 73 is a portion provided inside the first connecting hole 53. The end portion at the one axial side of the first gate portion 73 is located at a position that is closer to the other axial side than the end surface 51S at the one axial side of the first end plate 51. The first gate portion 73 does not protrude in the axial direction from the first end plate 51, and therefore, contact of the first gate portion 73 with other members can be suppressed.

[0064] The second gate portion 75 is located on the other axial side of the filling portion 71. The second gate portion 75 is a protruding portion protruding toward the other axial side from the second end surface 72S on the other axial side of the second filling portion 712. As shown in Figure 8 The second gate portion 75 is a portion provided on the inner side of the second connecting hole 54. The end portion of the second gate portion 75 on the other axial side is located at a position closer to the axial side than the end surface 52S of the second end plate 52 on the other axial side. The second gate portion 75 does not protrude in the axial direction from the second end plate 52, and thus, contact of the second gate portion 75 with other members can be suppressed.

[0065] In forming the resin member 70, resin is injected into the first connecting hole 53 of the first end plate 51. Also, the resin enters the insertion hole 43a of the first core block 41 and the insertion hole 43b of the second core block 42 via the first connecting hole 53. Furthermore, a part of the resin flows out of the insertion hole 43b through the second connecting hole 54. As shown in Figure 13 The second connecting hole 54 is disposed at a position overlapping both of the pair of insertion holes 43b, 43b in the axial direction. Thus, as shown in Figure 14 As shown in

[0066] As shown in Figure 12 The second connecting hole 54 of the second end plate 52 is located closer to the rotational axis 9 than the first connecting hole 53 of the first end plate 51. Thus, the second gate portion 75 located at the second connecting hole 54 is located closer to the rotational axis 9 than the first gate portion 73 provided at the first connecting hole 53. Thus, the resin flows from the radially outer side toward the radially inner side within the continuous hole 43. Thus, the magnet 60 can be fixed while being pressed against the radially inner side of the continuous hole 43, and the magnet 60 can be stably disposed within the continuous hole 43.

[0067] As shown in Figure 14 The second gate portions 75 provided at the pair of resin members 70, 70 are located between the pair of first gate portions 73, 73 in the circumferential direction, which the pair of resin members 70, 70 each have.

[0068] As shown in Figure 12 The third connecting hole 55 of the first end plate 51 communicates with the pair of insertion holes 43a, 43a located close to each other in the circumferential direction. That is, the third connecting hole 55 is disposed at a position straddling the pair of insertion holes 43a, 43a. The third connecting hole 55 releases gas generated by the resin from the insertion holes 43a when the resin is filled in the continuous hole 43. As shown in Figure 14As shown, a protrusion 77 is formed on the first end face 71S of the resin component 70 using the third connecting hole 55. In this example, a pair of resin components 70, 70 (more specifically, a pair of first filling portions 711) that are close to each other in the circumferential direction are connected by a protrusion 77 provided on one side of the axial direction. The protrusion 77 located in the third connecting hole 55 is located closer to the axis of rotation 9 than the first gate portion 73 located in the first connecting hole 53. As a result, the radial dimension of the protrusion 77 can be prevented from increasing, and the amount of resin component 70 used can be reduced.

[0069] like Figure 13 As shown, the fourth connecting hole 56 of the second end plate 52 communicates with the insertion hole 43b of the second iron core block 42. By filling the continuous hole 43 with resin, as... Figure 14 As shown, a protrusion 79 is formed on the resin member 70 using the fourth connecting hole 56. The protrusion 79 is provided on the second end face 72S of the filling portion 71.

[0070] <Manufacturing Method>

[0071] Figure 15 This is a flowchart of the manufacturing method of the rotor 3 according to the second embodiment. To manufacture the rotor 3, a preparation step S1 for preparing the core stack 40 is first performed. In preparation step S1, core blocks 41 and 42 are stacked in multiple layers axially. Adjacent core blocks 41 and 42 are arranged at an angle offset from each other around the rotation axis 9, and the insertion holes 43a and 43b of adjacent core blocks 41 and 42 are axially connected to each other. Preparation step S1 includes a magnet insertion step of inserting magnets 60 into the insertion holes 43a and 43b.

[0072] Following preparation step S1, a first welding step S2 is performed to weld the core blocks 41 and 42 together, a second welding step S3 to weld the first end plate 51 to the first core block 41, and a third welding step S4 to weld the second end plate 52 to the second core block 42. This forms a laminate containing the first end plate 51, core blocks 41 and 42, and the second end plate 52.

[0073] In the first, second, and third welding processes S2 to S4, the welding position is not particularly limited. As an example, when welding the first end plate 51 and the first core block 41, such as... Figure 12 As shown, welding positions P1, which are distributed in the circumferential direction, can be performed on the outer periphery of the first end plate 51. Furthermore, welding positions P2, which are distributed in the circumferential direction, can be performed on the inner periphery of the first end plate 51.

[0074] After the first, second, and third welding processes S2 to S4, a disposing process S5 of disposing the core stack 40 in the mold 80 is performed. Figure 16 is a perspective view showing an example of the mold 80. Figure 17 is a view showing an inner surface 82S of the other-side mold 82. In Figure 16 , the core stack 40 is shown by a broken line. In Figure 17 , the second core block 42 and the second end plate 52 are shown by a broken line.

[0075] The mold 80 has a one-side mold 81 disposed on one side in the axial direction and an other-side mold 82 disposed on the other side in the axial direction. The one-side mold 81 and the other-side mold 82 are each configured by combining a plurality of members. As shown in Figure 16 , the one-side mold 81 is provided with a plurality of (here, sixteen) injection ports 83. When the core stack 40 is disposed in the mold 80, each of the injection ports 83 communicates with the insertion hole 43a of the first core block 41 via the first connecting hole 53 of the first end plate 51.

[0076] As shown in Figure 17 , the inner surface 82S of the other-side mold 82 is provided with a plurality of (here, eight) flow ports 851. The flow ports 851 communicate with a resin accumulation portion 85 provided inside the other-side mold 82. When the core stack 40 is disposed in the mold 80, the second connecting hole 54 of the second end plate 52 overlaps the flow ports 851 in the axial direction. Thus, the resin accumulation portion 85 communicates with the insertion hole 43b of the second core block 42 via the flow ports 851 and the second connecting hole 54. Also, the fourth connecting hole 56 of the second end plate 52 is closed by the inner surface 82S of the other-side mold 82.

[0077] As shown in Figure 16 , the one-side mold 81 is provided with a plurality of (here, eight) discharge ports 87. When the core stack 40 is disposed in the mold 80, each of the discharge ports 87 communicates with the insertion hole 43a of the first core block 41 via the third connecting hole 55. Desirably, the discharge ports 87 are of a size that only gas generated by the resin passes therethrough and the resin does not flow in. Thus, the resin does not flow out of the discharge ports 87, and generation of burrs can be suppressed. It is preferable that the size of the discharge ports 87 on the other side in the axial direction be smaller than the size of the injection ports 83 on the other side in the axial direction.

[0078] After the disposing process S5, an injection process S6 of injecting the resin in a flow state into the injection ports 83 is performed. In the present example, the injection of the resin is performed substantially simultaneously for the sixteen injection ports 83. Note that it is not necessary to inject the resin into all of the injection ports 83 simultaneously.

[0079] After the injection step S6, a filling step S7 of filling the inside of the continuous hole 43 with the flowing resin is performed. By the filling step S7, the gap between the inner peripheral surface of the insertion hole 43a and the magnet 60 and the gap between the inner peripheral surface of the insertion hole 43b and the magnet 60 are filled with the resin.

[0080] The gaps between the insertion holes 43a, 43b and the magnet 60 are not uniform, and thus, in the continuous hole 43, there are portions where the flow path area of the resin is narrow. Therefore, it is difficult to make the resin flow uniformly inside the continuous hole 43 toward the other side in the axial direction. Therefore, even if the resin moves to the end portion of the insertion hole 43b on the other side in the axial direction, there can be portions in the continuous hole 43 where the resin is not filled.

[0081] In the filling step S7, the flowing resin injected into the mold 80 is caused to flow out to the resin accumulation portion 85 via the flow outlet 851 provided to the other side mold 82. Thereby, even if the resin moves locally shifted within the continuous hole 43, the resin that moves to the other side in the axial direction first can be caused to flow out from the continuous hole 43 to the resin accumulation portion 85 through the flow outlet 851 of the mold 80. Therefore, the inside of the continuous hole 43 can be filled with the resin well.

[0082] In particular, the core stack 40 has a skew structure, and thus, a pair of the insertion holes 43a, 43a and a pair of the insertion holes 43b, 43b that are close in the circumferential direction are arranged in a staggered manner in the circumferential direction. Therefore, the shape and size of the overlapping portion between the pair of the insertion holes 43a, 43a and the pair of the insertion holes 43b, 43b differ. According to the difference in the overlapping portion described above, the filling speed can differ between the pair of the continuous holes 43.

[0083] In the present embodiment, even if the filling speed of the resin differs between the pair of the continuous holes 43, 43, the resin of the side where the filling speed is fast can be caused to flow out from the flow outlet 851 to the resin accumulation portion 85. Therefore, the resin can be caused to spread well to both of the pair of the continuous holes 43, 43.

[0084] Furthermore, the resin that moves in the pair of the continuous holes 43, 43 can flow out to the resin accumulation portion 85 via the second connection hole 54 that communicates with both of the pair of the continuous holes 43, 43. Therefore, compared to a case where the connection hole 54 is provided for each continuous hole 43, the amount of the resin that flows out can be reduced.

[0085] In the filling step S7, when the resin injected into the continuous hole 43 generates gas, the gas is released from the release outlet 87 that communicates with the insertion hole 43a to the outside of the mold 80. Thereby, the filling failure of the resin due to the gas can be suppressed.

[0086] After the filling process S7 is ended, the core stack 40 is taken out from the mold 80 after the resin is cured by cooling. Next, a removal process S8 of removing the first gate portion 73 and a part of the second gate portion 75 from the core stack 40 is performed.

[0087] Figure 18 is a view showing the resin member 70 formed in the mold 80. As shown in Figure 18 the resin member 70 formed in the mold 80 has the first gate portion 731 having a shape corresponding to the injection port 83 and the second gate portion 751 having a shape corresponding to the flow port 851 and the resin accumulation portion 85. The first gate portion 731 has a portion protruding from the first connection hole 53. In the removal process S8, by removing the portion protruding from the first connection hole 53 in the first gate portion 731, the first gate portion 73 shown in Figure 14 is provided. Also, Figure 18 the second gate portion 751 shown in has a portion protruding from the second connection hole 54. In the removal process S8, by removing the portion protruding from the second connection hole 54 in the second gate portion 751, the second gate portion 75 shown in Figure 14 is provided.

[0088] According to the structure and the manufacturing method of the rotor 3 described above, the resin can be filled in the insertion holes 43a, 43b communicating in the axial direction at one time, and thus the number of processes can be reduced compared to the case where the resin is filled for each core block 41, 42. Also, when the resin in a flow state is injected from the injection port 83 of the mold 80, even if the resin moves locally shifted in the continuous hole 43, the resin that moves first can flow from the insertion hole 43b to the resin accumulation portion 85 via the flow port 851. Thus, the resin in a flow state can spread to the entire inside of the insertion holes 43a, 43b, and thus resin filling failure in the insertion holes 43a, 43b can be suppressed. Therefore, the productivity of the rotor 3 can be improved. Also, the position of the magnet 60A in the insertion holes 43a, 43b can be stabilized.

[0089] Also, the welding between the core blocks 41, 42 of the core stack 40 and the welding between the core stack 40 and the first end plate 51 and between the core stack 40 and the second end plate 52 can be performed at one time. Thus, the productivity of the traction motor 1 can be improved.

[0090] Further, by providing the end plates 51, 52 as members of the same shape, the second end plate 52 can be provided as a member obtained by reversing the first end plate 51. Thus, it is not necessary to separately manufacture the end plates 51, 52. Further, by providing the end plates 51, 52 as plate members provided with first through holes (connection holes 53, 56) and second through holes (connection holes 55, 54) of the same shape, it is possible to fill the resin into the insertion holes 43a, 43b of the core stack 40 after the end plates 51, 52 are attached to the core stack 40.

[0091] <3. Modified Examples>

[0092] The embodiments have been described above, but the present application is not limited to the above, and various modifications can be made.

[0093] For example, the core stack 40 is composed of two core pieces 41, 42, but one or more core pieces can be provided between these core pieces 41, 42. That is, the core stack 40 can be composed of three or more core pieces stacked.

[0094] Further, it is not necessary to connect the first end plate 51, the core pieces 41, 42, and the second end plate 52 by welding, respectively, and for example, the members can be connected by riveting, screw fastening, or other means.

[0095] The present application has been described in detail, but the above description is merely illustrative in all aspects and the present application is not limited thereto. It should be considered that numerous modified examples not illustrated can be conceived without departing from the scope of the present application. The structures described in each of the embodiments and each of the modified examples can be appropriately combined or omitted, provided that they do not contradict each other.

[0096] Industrial Applicability

[0097] The present application can be used for a rotor.

[0098] (Symbol Explanation)

[0099] 1 traction motor; 11 motor; 13 gear; 15 inverter; 23 stator; 3, 3A rotor; 40, 40A core stack; 41, 41A first core block; 41A, 42A core block; 42, 42A second core block; 43 continuous hole; 43a, 43b, 43A, 43B insertion hole; 51 first end plate; 51S end face; 52 second end plate; 52S end face; 53 first connection hole; 54 second connection hole; 55 third connection hole; 56 fourth connection hole; 60, 60A magnet; 70, 70A resin member; 71, 71A filling portion; 71S first end face; 72S second end face; 73, 731, 73A first gate portion; 75, 751, 75A second gate portion; 80, 80A mold; 81, 81A one side mold; 82, 82A other side mold; 83, 83A injection port; 851, 851A flow outlet; 87 discharge port; 9, 9A rotation axis.

Claims

1. A rotor that rotates about a rotational axis, the rotor comprising: a core stack that is configured by laminating a plurality of core blocks in an axial direction of the rotational axis, the core blocks being configured by a plurality of steel sheets laminated in the axial direction and having a plurality of insertion holes arranged in a circumferential direction; a plurality of magnets located inside the plurality of insertion holes; and a plurality of resin members that fix the magnets inside the plurality of insertion holes, the axially adjacent core blocks are located at positions that are angularly offset from each other about the rotational axis, the insertion holes of the axially adjacent core blocks communicate with each other in the axial direction, the resin member includes: a filling portion located inside the insertion hole; a first gate portion located on an axial one side in the filling portion; and a second gate portion located on an axial other side in the filling portion, the plurality of insertion holes include a pair of insertion holes that are close to each other in the circumferential direction and have a V-shape in which the pair of insertion holes are away from each other in the circumferential direction as they go toward a radially outer side, the second gate portion is located closer to the rotational axis than the first gate portion, the plurality of resin members include a pair of resin members located inside the pair of insertion holes, and the second gate portions provided to the pair of resin members are located between a pair of the first gate portions that the pair of resin members have in the circumferential direction.

2. The rotor according to claim 1, wherein the first gate portion is a protrusion that protrudes from a first end surface on the axial one side of the filling portion toward the axial one side.

3. The rotor according to claim 1 or 2, wherein the second gate portion is a protrusion that protrudes from a second end surface on the axial other side of the filling portion toward the axial other side.

4. The rotor according to claim 1 or 2, further comprising a first end plate located on the axial one side of the core stack and having a first connection hole that communicates with the insertion hole of a first core block that is an end portion on the axial one side among the plurality of core blocks, and the first gate portion overlaps the first connection hole in the axial direction.

5. The rotor according to claim 4, wherein an end portion on the axial one side of the first gate portion is located closer to the axial other side than an end surface on the axial one side of the first end plate.

6. The rotor according to claim 1, further comprising a second end plate located on the axial other side of the core stack and having a second connection hole that communicates with the insertion hole of a second core block that is an end portion on the axial other side among the plurality of core blocks, and the second gate portion overlaps the second connection hole in the axial direction.

7. The rotor according to claim 6, wherein an end portion on the axial other side of the second gate portion is located closer to the axial one side than an end surface on the axial other side of the second end plate.

8. The rotor according to claim 6 or 7, wherein the second connection hole communicates with two insertion holes that are close to each other in the circumferential direction among the second core blocks. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 9. The rotor according to claim 5, wherein a second end plate is provided on the other axial side of the core stack and has a second connection hole that communicates with the insertion hole of a second core piece of the end portion on the other axial side among the plurality of core pieces, the second gate portion overlaps the second connection hole in the axial direction, the first end plate and the second end plate are identical in shape.

10. The rotor according to claim 4, wherein the first end plate further has a third connection hole that communicates with the insertion hole of the first core piece.

11. The rotor according to claim 10, wherein the third connection hole is located closer to the rotation axis than the first connection hole.

12. The rotor according to claim 10 or 11, wherein the resin member has a protrusion that protrudes from the filling portion toward the one axial side and is located inside the third connection hole.

13. A rotor that rotates about a rotation axis, the rotor comprising: a core stack that is composed of core pieces stacked in the axial direction of the rotation axis in a plurality of layers, the core pieces being composed of a plurality of steel sheets stacked in the axial direction and having a plurality of insertion holes arranged in the circumferential direction; a plurality of magnets located inside the plurality of insertion holes; and a plurality of resin members that fix the magnets to the inside of the plurality of insertion holes, the core pieces that are axially adjacent are located at positions that are angularly offset from each other about the rotation axis, the insertion holes of the core pieces that are axially adjacent communicate with each other in the axial direction, the resin member includes: a filling portion located inside the insertion hole; a first gate portion located on the one axial side in the filling portion; and a second gate portion located on the other axial side in the filling portion, in the circumferential direction, the first gate portion is located at the center of the insertion hole, in the circumferential direction, the second gate portion is located at the center of the insertion hole that communicates with the insertion hole in the axial direction, the circumferential positions of the first gate portion and the second gate portion are different from each other.

14. The rotor according to claim 13, wherein the first gate portion is a protrusion that protrudes from a first end surface on the one axial side of the filling portion toward the one axial side.

15. The rotor according to claim 13 or 14, wherein the second gate portion is a protrusion that protrudes from a second end surface on the other axial side of the filling portion toward the other axial side.

16. The rotor according to claim 13 or 14, wherein the plurality of insertion holes include a pair of insertion holes that are close to each other in the circumferential direction and are in a V shape that diverges from each other in the circumferential direction as it goes toward the radially outer side.

17. The rotor according to claim 13 or 14, further comprising a first end plate located on the one axial side of the core stack and having a first connection hole that communicates with the insertion hole of a first core piece of the end portion on the one axial side among the plurality of core pieces, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The first gate portion overlaps the first connection hole in the axial direction.

18. The rotor according to claim 17, wherein An end portion of the first gate portion on the one axial side is located at a position further on the other axial side than an end surface of the first end plate on the one axial side.

19. The rotor according to claim 13, wherein Further comprising a second end plate located on the other axial side of the core stack and having a second connection hole communicating with the insertion hole of a second core block of the plurality of core blocks on the other axial side end portion, The second gate portion overlaps the second connection hole in the axial direction.

20. The rotor according to claim 19, wherein An end portion of the second gate portion on the other axial side is located at a position further on the one axial side than an end surface of the second end plate on the other axial side.

21. The rotor according to claim 19 or 20, wherein The second connection hole communicates with two insertion holes of the second core block that are close in the circumferential direction.

22. The rotor according to claim 18, wherein Further comprising a second end plate located on the other axial side of the core stack and having a second connection hole communicating with the insertion hole of a second core block of the plurality of core blocks on the other axial side end portion, The second gate portion overlaps the second connection hole in the axial direction, The first end plate and the second end plate are identical in shape.

23. The rotor according to claim 17, wherein The first end plate further has a third connection hole communicating with the insertion hole of the first core block.

24. The rotor according to claim 23, wherein The third connection hole is located closer to the rotational axis than the first connection hole.

25. The rotor according to claim 23 or 24, wherein The resin member has a protruding portion protruding toward the one axial side from the filling portion and located inside the third connection hole.

26. A traction motor having: a motor including the rotor according to any one of claims 1 to 25 and a stator supporting the rotor so as to be rotatable; a gear connected to the motor; and an inverter electrically connected to the motor.

27. A manufacturing method of a rotor that rotates with a rotational axis as a center, the method comprising: a process (a) of preparing a core stack constituted by core blocks laminated in the axial direction of the rotational axis in multiple layers, the core blocks being constituted by a plurality of steel sheets laminated in the axial direction and having a plurality of insertion holes arranged in the circumferential direction, the axially adjacent core blocks being located at positions angularly offset from each other with the rotational axis as the center, the insertion holes of the axially adjacent core blocks communicating with each other in the axial direction; and a process (b) of forming a plurality of resin members that fix magnets to the inside of a plurality of the insertion holes of the core stack, the process (b) including: (b1) disposing the iron core stack in a mold composed of one side mold and the other side mold; (b2) after the step (b1), injecting a flowing resin into an injection port provided in the one side mold and communicating with the insertion hole of the first iron core block of the plurality of iron core blocks on the one side in the axial direction; and (b3) causing the flowing resin injected into the mold in the step (b2) to flow to a resin accumulation portion provided in the other side mold and communicating with the insertion hole of the second iron core block of the plurality of iron core blocks on the other side in the axial direction, and to fill the insertion hole, the plurality of insertion holes include a pair of insertion holes that are close to each other in the circumferential direction and have a V shape in which the distance between the insertion holes increases as the radial direction is approached, the second gate portion formed in the resin accumulation portion in the resin member is located closer to the rotation axis than the first gate portion formed in the injection port, the plurality of resin members include a pair of resin members located on the inner side of the pair of insertion holes, the second gate portions provided in the pair of resin members are located between the pair of first gate portions possessed by the pair of resin members in the circumferential direction.

28. The method of manufacturing a rotor of claim 27, wherein, Further comprising: (c) before the step (b2), inserting the magnet into the insertion hole; and (d) after the step (b3), removing at least a portion of the first gate portion formed in the injection port and at least a portion of the second gate portion formed in the resin accumulation portion in the resin member.

29. The manufacturing method of the rotor according to claim 27 or 28, wherein Further comprising (e) before the step (b2), welding the iron core blocks adjacent in the axial direction to each other.

30. The manufacturing method of the rotor according to claim 27 or 28, wherein Further comprising (f1) before the step (b2), welding a first end plate having a first connection hole communicating with the insertion hole of the first iron core block to an end surface on the one side in the axial direction of the first iron core block.

31. The manufacturing method of the rotor according to claim 27 or 28, wherein Further comprising (f2) before the step (b2), welding a second end plate having a second connection hole communicating with the insertion hole of the second iron core block to an end surface on the other side in the axial direction of the second iron core block.

32. A manufacturing method of a rotor that rotates around a rotation axis, the method comprising: (a) preparing an iron core stack composed of iron core blocks by laminating a plurality of layers in the axial direction of the rotation axis, the iron core blocks being composed of a plurality of steel plates laminated in the axial direction and having a plurality of insertion holes arranged in the circumferential direction, the iron core blocks adjacent in the axial direction being located at positions that are angularly offset from each other around the rotation axis, the insertion holes of the iron core blocks adjacent in the axial direction communicating with each other in the axial direction; and (b) laminating the iron core blocks in the axial direction of the rotation axis. The process (b) includes forming a plurality of resin members that fix the magnets to the inside of the plurality of insertion holes of the core stack, The process (b) includes: A process (b1) of disposing the core stack in a mold composed of one side mold and the other side mold; A process (b2) of injecting a flowing resin into an injection port provided in the one side mold and communicating with the insertion hole of the first core block of the plurality of core blocks on the one side in the axial direction after the process (b1); and A process (b3) of causing the flowing resin injected into the mold in the process (b2) to flow to a resin accumulation portion provided in the other side mold and communicating with the insertion hole of the second core block of the plurality of core blocks on the other side in the axial direction, and to fill the insertion hole, In the circumferential direction, a first gate portion formed in the resin member in the injection port is located at the center of the insertion hole, In the circumferential direction, a second gate portion formed in the resin member in the resin accumulation portion is located at the center of the insertion hole communicating with the insertion hole in the axial direction, The circumferential positions of the first gate portion and the second gate portion are different from each other.

33. The method of manufacturing a rotor of claim 32, wherein, Further comprising: A process (c) of inserting the magnet into the insertion hole before the process (b2); and A removal process (d) of removing at least a part of the first gate portion formed in the resin member in the injection port and at least a part of the second gate portion formed in the resin member in the resin accumulation portion after the process (b3).

34. The manufacturing method of the rotor according to claim 32 or 33, wherein Further comprising a process (e) of welding the core blocks adjacent in the axial direction to each other before the process (b2).

35. The manufacturing method of the rotor according to claim 32 or 33, wherein Further comprising a process (f1) of welding a first end plate having a first connection hole communicating with the insertion hole of the first core block to an end surface on the one side in the axial direction of the first core block before the process (b2).

36. The manufacturing method of the rotor according to claim 32 or 33, wherein Further comprising a process (f2) of welding a second end plate having a second connection hole communicating with the insertion hole of the second core block to an end surface on the other side in the axial direction of the second core block before the process (b2). ​

Images