Motor rotor

Abstract

In order to provide a motor rotor with which it is possible to reduce manufacturing steps and the number of components necessary for manufacturing, a motor rotor (10) comprises: a rotor core (13) that has magnet insertion holes (14) and that is configured by layering a plurality of steel sheets (11, 12) in the axial direction; magnets (15) inserted into the magnet insertion holes; and resin members (16) that fill the magnet insertion holes and fix the magnets in the magnet insertion holes. Among the plurality of steel sheets, at least one of the steel sheets (12), that is located on the axially outermost side, has an identical shape to the other located on the axially inner side, and is fixed with the phase thereof about the axis being shifted.

Description

[Technical Field]

[0001] The present invention relates to a rotor for a motor. [Background technology]

[0002] Conventionally, a motor rotor has been known that includes a rotor core made of multiple laminated steel plates and having magnet insertion holes, magnets that are inserted into the magnet insertion holes, and a resin member that is filled into the magnet insertion holes and fixes the magnets within the magnet insertion holes. Patent Documents 1 and 2 disclose a structure in which a through hole is provided in a part of an end plate, and a magnet is exposed on the surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6075300 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-212582 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the technology described in Patent Document 1, the two sheets at both ends of the stacking direction of the rotor's multiple electromagnetic steel plates have different shapes, and therefore are manufactured using different punching dies. Also, in the technology described in Patent Document 2, a fixing member that is separate from the multiple electromagnetic steel plates of the rotor is used. These technologies require the multiple electromagnetic steel plates of the rotor and the members at both ends to be manufactured in separate processes, so there has been a demand for reducing the number of work processes and the number of parts required for manufacturing.

[0005] The present invention has been made in view of the above circumstances, and aims to achieve the object of providing a motor rotor that can reduce the number of manufacturing steps and the number of parts required for manufacturing. [Means for solving the problem]

[0006] As a means for solving the above problem, a rotor of a motor according to one aspect of the present invention as set forth in claim 1 comprises: A shaft (20); a rotor core (13) formed by laminating a plurality of steel plates (11, 12) in the axial direction and having magnet insertion holes (14); a magnet (15) to be inserted into the magnet insertion hole (14); a resin member (16) filled in the magnet insertion hole (14) to fix the magnet (15) in the magnet insertion hole (14); A rotor (10) of a motor comprising: At least one of the steel plates (12) located on the outermost side in the axial direction among the plurality of steel plates (11, 12) has the same shape as the other steel plates (11) located on the inner side in the axial direction and is fixed with a phase shift around the axis. The rotor of the motor of the present invention as set forth in claim 2 comprises: The steel plates (11, 12) are provided with through holes (14a, 17a), The steel plate (12) positioned outermost in the axial direction is fixed in a state in which at least a part of the magnet insertion hole (14) of the other steel plate (11) positioned inner in the axial direction is exposed from the through hole (17a) of the steel plate (12). It is possible. The rotor of the motor of the present invention as set forth in claim 3 comprises: A plurality of magnets (15) are arranged in each of the magnet insertion holes (14) on the plane of the steel plate (11), The magnets (15) are fixed in a state in which the gaps (15a) between the magnets (15) arranged side by side are exposed from the through-holes (17a) of the steel plate (12) located at the outermost position in the axial direction. It is possible. The rotor of the motor of the present invention as set forth in claim 4 comprises: The plurality of steel plates (11, 12) have protrusions (11a, 12a) that protrude radially inward relative to the axis, and the shaft (20) has axial grooves (21) along the axial direction that engage with the protrusions (11a, 12a), and a circumferential groove (22) that extends circumferentially from the axial groove (21) is formed at a position where the protrusion (12a) of the steel plate (12) located outermost in the axial direction of the shaft (20) is fixed. (5) In one example, the circumferential length of the circumferential groove (22) is set equal to the dimension of the circumferential movement of the protrusion (12a) corresponding to the phase around the axis that fixes the steel plate (12) located at the outermost position in the axial direction. (6) In one example, the plurality of steel plates (11, 12) have protrusions (11a, 12a) that protrude radially inward relative to the axis, and the shaft (20) has an axial groove (21) that is provided along the axial direction and engages with the protrusion (11a), and another axial groove (23) that is provided along the axial direction at a circumferentially different position from the axial groove and engages with the protrusion (12a) of the steel plate that is located outermost in the axial direction. (7) A rotor of a motor according to a second aspect of the present invention includes a shaft (20), a rotor core (13) formed by stacking a plurality of steel plates (11, 12) in the axial direction and having magnet insertion holes (14), and magnets (15) inserted into the magnet insertion holes (14). and a resin member (16) filled in the magnet insertion hole (14) to fix the magnet (15) in the magnet insertion hole (14), wherein at least one of the steel plates (12) located outermost in the axial direction among the plurality of steel plates (11, 12) has the same shape as the other steel plate (11) located inner in the axial direction and is fixed with a phase shift around the axis, and the other steel plate (11) located inner in the axial direction among the plurality of steel plates (11, 12) has a protruding portion (11a) protruding radially inward relative to the axis, and the shaft (20) is provided with an axial groove (21) along the axial direction that fits into the protruding portion (11a), and the steel plate (12) located outermost in the axial direction has the same shape as the other steel plate (11) located inner in the axial direction except that the protruding portion does not protrude. (8) In one example, the steel plates (11, 12) are provided with through holes (14a, 17a), and the steel plate (12) located at the outermost side in the axial direction is fixed in a state where at least a portion of the magnet insertion hole (14) of the other steel plate (11) located inside in the axial direction is exposed from the through hole (17a) of the steel plate (12) located at the outermost side in the axial direction. (9) In one example, a plurality of magnets (15) are arranged in a line on the plane of the steel plate (11) in one of the magnet insertion holes (14), and the gaps (15a) between the lined-up magnets (15) are fixed in a state where they are exposed from the through hole (17a) of the steel plate (12) located at the outermost position in the axial direction. [Effects of the Invention]

[0007] According to the rotor of the first aspect, the outermost steel plate (end plate) is also of the same shape as the other steel plates, so it can be manufactured at low cost without using separate or complicated molds. By fixing the outermost steel plate with a phase shift, the inner magnets overlap with the magnet insertion holes of the outermost steel plate when viewed in the axial direction, preventing the magnets from falling out. At the same time, part of the magnet can be exposed from the magnet insertion holes of the outermost steel plate, improving the cooling performance of the magnets.

[0008] In the example (2) above, the magnet insertion hole in the inner steel plate is exposed through the through hole in the outermost steel plate. Therefore, even if foreign matter gets into the magnet insertion hole, it can be expelled from the rotor through the through hole in the outermost steel plate. For example, foreign matter that has adhered to the outer wall due to the centrifugal force of the rotor's rotation can be expelled by changing the rotor's rotation speed. Foreign matter here refers to dust, moisture from condensation, motor wear powder, etc. In the example (3) above, the above-mentioned foreign matter is likely to get trapped in the gaps between the magnets, but by exposing these gaps through the through holes in the outermost steel plate, it is possible to make it easier for the foreign matter to be expelled outside the rotor.

[0009] In the example of (4) above, the provision of axial and circumferential grooves prevents misalignment of the steel plate and shaft. Also, because the circumferential groove is provided on the outer peripheral surface of the shaft where the outermost steel plate (end plate) in the axial direction is located, the end plate can be rotated along the circumferential groove, allowing it to be easily shifted in phase with the inner steel plate and fixed in place. In the example (5) above, the circumferential groove is cut to an extent corresponding to the phase by which the outermost steel plate is shifted relative to the inner steel plate, so that the protrusion abuts against the end of the circumferential groove, making it easy to position the outermost steel plate relative to the inner steel plate.

[0010] In the example (6) above, the provision of an axial groove prevents misalignment of the steel plate and shaft. Also, since there is another axial groove that fits into the protrusion of the outermost steel plate (end plate) in the axial direction, by shifting the end plate and fitting it into the other axial groove, it can be easily shifted in phase with the inner steel plate and fixed.

[0011] In the rotor according to the second aspect, the provision of axial grooves prevents misalignment of the steel plates and the shaft. Furthermore, because the axially outermost steel plates (end plates) are not provided with protrusions, the protrusions do not get in the way when assembling the end plates to the shaft, and the end plates can be easily fixed with a phase shift relative to the inner steel plates in the axial direction.

[0012] In the example (8) above, the magnet insertion hole in the inner steel plate is exposed through the through hole in the outermost steel plate. Therefore, even if foreign matter gets into the magnet insertion hole, it can be expelled from the rotor through the through hole in the outermost steel plate. For example, foreign matter that has adhered to the outer wall due to the centrifugal force of the rotor's rotation can be expelled by changes in the rotor's rotation speed. Foreign matter here refers to dust, moisture from condensation, motor wear powder, etc. In the example (9) above, the above-mentioned foreign matter is likely to get trapped in the gaps between the magnets, but by exposing these gaps through the through holes in the outermost steel plate, it is possible to make it easier for the foreign matter to be expelled outside the rotor.

[0013] According to the present invention, it is possible to provide a motor rotor that can reduce the number of manufacturing steps and the number of parts required for manufacturing. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a cross-sectional view showing a first embodiment of a rotor of a motor according to the present invention. [Figure 2] 1 is a front view of a rotor of a motor according to a first embodiment of the present invention, viewed in the axial direction. [Figure 3] 1 is a perspective view showing an axially inner steel plate in a first embodiment of a rotor for a motor according to the present invention; [Figure 4] 1 is a perspective view showing a shaft in a first embodiment of a rotor of a motor according to the present invention. [Figure 5] FIG. 10 is a view of a rotor of a motor according to a second embodiment of the present invention, as viewed in the axial direction. [Figure 6] FIG. 10 is a perspective view showing an axially inner steel plate in a second embodiment of a rotor for a motor according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] A first embodiment of a rotor for a motor according to the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing the rotor of the motor in this embodiment, FIG. 2 is a front view of the rotor core in the axial direction in this embodiment, FIG. 3 is a perspective view showing the inner steel plate in the axial direction of the rotor of the motor in this embodiment, and FIG. 4 is a perspective view of the shaft in this embodiment, in which the symbol 10 indicates the rotor of the motor.

[0016] The rotor 10 of the motor according to this embodiment is configured as a rotor of a synchronous motor mounted on an electric vehicle, a hybrid vehicle, a fuel cell vehicle, or the like. As shown in Figures 1 to 3, the rotor 10 of the motor according to this embodiment comprises a hollow cylindrical rotor core 13 formed by laminating a plurality of hollow, disc-shaped electromagnetic steel plates (steel plates) 11, 12, a plurality of magnets 15 inserted into a plurality of slots (magnet insertion holes) 14 formed in the rotor core 13, and a resin member 16 formed as a thermosetting resin that is filled into the slots 14 and heated to fix the magnets 15 within the slots 14. The rotor core 13 is fixed to the shaft 20 .

[0017] The multiple electromagnetic steel plates 11 and the two electromagnetic steel plates 12 all have the same contour shape. The electromagnetic steel plates (steel plates) 11, 12 are stacked in multiple layers in the axial direction of the shaft 20, and all of the electromagnetic steel plates 11, 12 have the same contour shape. The electromagnetic steel plate 11, which is on the inside in the axial direction of the shaft 20, is a steel plate with a substantially circular contour, with multiple slots (magnet insertion holes) 14, multiple through holes 14a, multiple through holes 14b, and a central hole 13a penetrating through it. In the disk-shaped electromagnetic steel plate 11, the multiple slots (magnet insertion holes) 14 are arranged on the periphery, and in the electromagnetic steel plate 11, the multiple through holes 14a and through holes 14b are arranged alternately around the central hole 13a. The plurality of slots (magnet insertion holes) 14, the plurality of through holes 14a, and the plurality of through holes 14b are formed symmetrically with respect to the axis of the shaft 20 around the central hole 13a.

[0018] The electromagnetic steel plates 12 at both ends of the rotor core 13 in the stacking direction, i.e., the outermost in the axial direction, have the same approximately circular outline shape as the electromagnetic steel plates 11, and are penetrated by a plurality of slots (magnet insertion holes) 17, a plurality of through holes 17a, a plurality of through holes 17b, and a central hole 13a. Between electromagnetic steel plate 11 and electromagnetic steel plate 12, the shapes and arrangement of the multiple slots (magnet insertion holes) 14 and slots (magnet insertion holes) 17, the shapes and arrangement of the multiple through holes 14a and through holes 17a, and the shapes and arrangement of the multiple through holes 14b and through holes 17b all correspond to each other and have the same shapes and arrangements.

[0019] Slots 14 are formed near the outer periphery of electromagnetic steel plate 11 and are formed in a generally arcuate shape to allow magnetic lines of force from a stator (not shown) to pass easily. An example of a magnetic line of force is shown in the figure as arrow B. Multiple slots 14 are formed adjacent to each other in the circumferential direction of electromagnetic steel plate 11 so as to have a predetermined phase. Through holes 14a and 14b are formed radially inward of slots 14 in magnetic steel plate 11. Through holes 14a and 14b are formed spaced apart from slots 14 and center hole 13a.

[0020] The through hole 14a has a larger radial size than the through hole 14b. The through hole 14a is formed so that its radially outer position is the same as the radial position of the slot 14. The through hole 14a is arranged in a different circumferential position from the slot 14. Note that the area of ​​the through hole 14b when viewed in the axial direction is smaller than that of the through hole 14a. Furthermore, the through hole 17b has a portion that coincides with the through hole 14a and communicates with the outside of the rotor core 13.

[0021] As shown in Fig. 2, the electromagnetic steel sheets 11 and 12 are fixed to the shaft 20 with a phase shift around the axis of the shaft 20. The electromagnetic steel sheets 12 that are outermost in the axial direction are shifted around the axis by an angle that is slightly smaller than the phase of the adjacent slots 14 in the inner electromagnetic steel sheets 11. This causes the through holes 14a to coincide with part of the slots 14. Because the outermost electromagnetic steel sheets 12 are arranged in this manner with respect to the rotor core 13, each of the outermost electromagnetic steel sheets 12 has an area that does not overlap with the magnets 15 in the radial direction when viewed in the axial direction.

[0022] Gaps 15a are formed between adjacent magnets 15 arranged inside slots 14. These gaps 15a coincide with through holes 17a when viewed in the axial direction. In other words, gaps 15a communicate with the outside of rotor core 13 via through holes 17a. Furthermore, electromagnetic steel sheets 12 are arranged so that a portion of each magnet 15 overlaps with each magnet 15 when viewed in the axial direction. For this reason, the axial end faces of magnets 15 are not covered by electromagnetic steel sheets 12 and are prevented from protruding from rotor core 13.

[0023] The magnet 15 has a quadrangular prism shape with a rectangular cross section perpendicular to the longitudinal direction (axial direction). Alternatively, multiple magnets 15 may be arranged in the slots 14, with gaps 15a formed between adjacent magnets 15 filled with a resin member 16. The magnets 15 are fixed to the rotor core 13 by the resin member 16 filled in the slots 14. The magnets 15 may be permanent magnets. The magnets 15 are rod-shaped hard magnetic bodies made by sintering powders of, for example, ferrite or neodymium, and may not be magnetized before being accommodated in the slots 14, but may be magnetized after being fixed to the rotor core 13.

[0024] Protrusions 11a and 12a that protrude toward the center are formed on the outer periphery of central hole 13a in electromagnetic steel plates 11 and 12. Protrusions 11a and 12a are provided in two locations symmetrically about the center of central hole 13a. Protrusions 11a and 12a are formed as a substantially rectangular outline extending from the outer periphery of central hole 13a.

[0025] Two axial grooves 21 extending in the axial direction are formed on the outer periphery of the shaft 20. The number of axial grooves 21 is set to correspond to the number of protrusions 11a, 12a. The cross-sectional shape of the axial grooves 21 corresponds to the contour shapes of the protrusions 11a, 12a. The axial grooves 21 allow the protrusions 11a, 12a to slide in the axial direction of the shaft 20. The shaft 20 is assembled so that when it is inserted into the central holes 13a of the electromagnetic steel plates 11, 12, the protrusions 11a, 12a move axially inside the axial grooves 21.

[0026] As shown in Fig. 4, on the outer periphery of the shaft 20, circumferential grooves 22 extending in the circumferential direction are connected to the axial grooves 21. The circumferential grooves 22 are formed at axial positions corresponding to the outermost electromagnetic steel sheets 12 when the rotor core 13 is attached to the shaft 20. The circumferential grooves 22 have a circumferential length corresponding to the length for rotating and fixing the outermost electromagnetic steel sheets 12 around the axis so as to be in a predetermined phase with respect to the inner electromagnetic steel sheets 11. In other words, by abutting the protrusions 12a against the circumferential ends 22a of the circumferential grooves 22, it is possible to set the position of the outermost electromagnetic steel sheets 12 to be rotated around the axis so as to be in a predetermined phase with respect to the inner electromagnetic steel sheets 11.

[0027] In rotor 10 of the motor of this embodiment, electromagnetic steel sheets 11 and 12 are formed by pressing thin electromagnetic steel sheets. At this time, electromagnetic steel sheets 11 and 12 are formed to have the same shape. That is, slots 14 and 17, through holes 14a and 17a, through holes 14b and 17b, center hole 13a, and protrusions 11a and 12a are all formed to have the same shape and in the same positions. Then, in the lamination process, multiple electromagnetic steel sheets 11 are stacked in the thickness direction, and magnets 15 are inserted into the formed slots 14 and fixed with resin members 16.

[0028] Furthermore, electromagnetic steel plate 12 is aligned on both outer sides of laminated electromagnetic steel plate 11 so that slots 14 and 17, through holes 14a and 17a, through holes 14b and 17b, center hole 13a, and protrusions 11a and 12a are in the same positions, and shaft 20 is inserted into center hole 13a so that protrusions 11a and 12a are aligned with axial groove 21. Next, when the electromagnetic steel sheet 12 has moved to an axial position corresponding to the circumferential groove 22, the electromagnetic steel sheet 12 is rotated along the circumferential groove 22. When the protruding portion 12a comes into contact with the circumferential end portion 22a, the electromagnetic steel sheet 12 is set to the attachment position, and the electromagnetic steel sheets 11 and 12 are fixed by a fixing device or the like (not shown).

[0029] According to the motor rotor 10 of this embodiment, the axially outermost electromagnetic steel sheet 12 has the same shape as the inner electromagnetic steel sheet 11, so there is no need to use different press dies or to complicate the dies. As a result, only one type of die is required and the number of press steps using different dies can be reduced, resulting in a reduction in the number of steps and low-cost manufacturing.

[0030] Furthermore, by fixing the outermost electromagnetic steel sheet 12 out of phase with the electromagnetic steel sheets 11 stacked on the inside, the inner magnet 15 and the magnet insertion hole 17 of the outermost electromagnetic steel sheet 12 are positioned to overlap when viewed in the axial direction. This makes it possible to prevent the magnet 15 from falling off. At the same time, part of the magnet 15 can be exposed from the magnet insertion hole 17 of the outermost electromagnetic steel sheet 12, making it possible to improve the cooling performance of the magnet 15.

[0031] According to the rotor 10 of the motor of this embodiment, the magnet insertion holes 14 of the innermost electromagnetic steel plate 11 are exposed from the through holes 17a of the outermost electromagnetic steel plate 12 when viewed in the axial direction. Therefore, even if foreign matter gets into the magnet insertion holes 14, the foreign matter can be expelled from the rotor core 13 through the through holes 17a of the outermost electromagnetic steel plate 12. For example, foreign matter that has adhered to the outer wall due to the centrifugal force of the rotation of the rotor core 13 can be expelled by changes in the rotation speed of the rotor core 13. The foreign matter referred to here includes dust, moisture due to condensation, motor wear powder, etc. Furthermore, although the above-mentioned foreign matter is likely to get mixed into the gap 15a formed between the magnets 15, by exposing this gap 15a from the through hole 17a of the outermost electromagnetic steel plate 12, it is possible to easily expel the foreign matter to the outside of the rotor core 13.

[0032] According to the rotor 10 of the motor of this embodiment, the axial grooves 21 and the circumferential grooves 22 are provided on the outer peripheral surface of the shaft 20, so that the electromagnetic steel plates 11, 12 and the shaft 20 are fixed without misalignment. Furthermore, the circumferential groove 22 is provided on the outer peripheral surface of the shaft 20 at a position corresponding to the outermost electromagnetic steel plate (end face plate) 12 in the axial direction. Therefore, when attaching the electromagnetic steel plates 11, 12 to the shaft 20, simply by rotating the electromagnetic steel plate 12 along the circumferential groove 22, the electromagnetic steel plate 12 can be easily fixed with a phase shift relative to the inner electromagnetic steel plate 11 whose protrusion 11a is fitted in the axial groove 21.

[0033] According to the rotor 10 of the motor of this embodiment, the circumferential length of the circumferential groove 22 is formed to be equal to the length corresponding to the phase by which the outermost electromagnetic steel sheet 12 is shifted relative to the inner electromagnetic steel sheet 11. Therefore, simply by abutting the protrusion 12a against the end 22a of the circumferential groove 22, it becomes possible to easily position the outermost electromagnetic steel sheet 12 relative to the inner electromagnetic steel sheet 11.

[0034] According to the motor rotor 10 of this embodiment, it is possible to provide an advantageous effect that it is possible to reduce the number of manufacturing steps and to reduce the number of parts required for manufacturing the motor rotor.

[0035] A second embodiment of a rotor for a motor according to the present invention will be described below with reference to the drawings. FIG. 5 is a front view of the rotor core in the axial direction in this embodiment, and FIG. 3 is a front view of the steel plate on the inner axial side of the rotor of the motor in this embodiment. This embodiment differs from the first embodiment described above in terms of the shape of the steel plate.

[0036] The rotor 30 of the motor according to this embodiment is configured as a rotor of a synchronous motor mounted on an electric vehicle, a hybrid vehicle, a fuel cell vehicle, or the like, similarly to the first embodiment. As shown in Figures 5 and 6, the rotor 30 of the motor according to this embodiment comprises a hollow cylindrical rotor core 33 formed by laminating a plurality of hollow disc-shaped electromagnetic steel plates (steel plates) 31, 32, a plurality of magnets 35 inserted into a plurality of slots (magnet insertion holes) 34 formed in the rotor core 33, and a resin member 36 formed as a thermosetting resin that is filled into the slots 34 and heated to fix the magnets 35 within the slots 34. The rotor core 33 is fixed to the shaft 20 in the same manner as in the first embodiment (see FIG. 4).

[0037] The multiple electromagnetic steel plates 31 and the two electromagnetic steel plates 32 all have the same contour shape. The electromagnetic steel plates (steel plates) 31, 32 are stacked in multiple layers in the axial direction of the shaft 20, and all of the steel plates 31, 32 have the same contour shape. That is, the electromagnetic steel plate 31, which is on the inner side in the axial direction of the shaft 20, is a steel plate with a substantially circular contour, through which multiple slots (magnet insertion holes) 34, multiple through holes 34a, and a central hole 33a penetrate. In the electromagnetic steel plate 31 with a circular contour, the multiple slots (magnet insertion holes) 34 are arranged on the periphery, and in the electromagnetic steel plate 31, the multiple through holes 34a are arranged around the central hole 33a and radially inward of the slots 34. The multiple slots (magnet insertion holes) 34 and the multiple through holes 34a are formed symmetrically around the central hole 33a with respect to the axis of the shaft 20.

[0038] The electromagnetic steel plates 32 at both ends of the rotor core 33 in the stacking direction, i.e., the outermost in the axial direction, have the same approximately circular outline shape as the electromagnetic steel plates 31, and are penetrated by multiple slots (magnet insertion holes) 37, multiple through holes 37a, and a central hole 33a. The shapes and arrangements of the multiple slots (magnet insertion holes) 34 and slots (magnet insertion holes) 37, and the shapes and arrangements of the multiple through holes 34a and through holes 37a in electromagnetic steel plate 31 and electromagnetic steel plate 32 all correspond to each other and have the same shapes and arrangements.

[0039] The slots 34 are formed near the outer periphery of the electromagnetic steel plate 31 and are formed so as to allow magnetic lines of force from a stator (not shown) to pass easily. The multiple slots 34 are formed adjacent to each other in the circumferential direction of the electromagnetic steel plate 31 so as to have a predetermined phase. The through holes 34a are formed radially inward of the slots 34 of the electromagnetic steel plate 31. The through holes 34a are formed spaced apart from the slots 34 and the central hole 33a. The through holes 34a are formed in a substantially triangular outline.

[0040] As shown in Fig. 5, the electromagnetic steel sheets 31 and 32 are fixed to the shaft 20 with a phase shift around the axis of the shaft 20. The electromagnetic steel sheets 32 that are outermost in the axial direction are shifted around the axis by an angle that is slightly smaller than the phase of the adjacent slots 34 formed in the inner electromagnetic steel sheets 31. As a result, the slots 37 coincide with part of the slots 34. Because the outermost electromagnetic steel sheets 32 are arranged in this manner with respect to the rotor core 33, each of the outermost electromagnetic steel sheets 32 has an area that does not overlap with the magnets 35 in the radial direction when viewed in the axial direction.

[0041] Gaps 35a are formed between adjacent magnets 35 arranged inside slots 34. These gaps 35a coincide with slots 37 when viewed in the axial direction. In other words, gaps 35a communicate with the outside of rotor core 33 via slots 37. Furthermore, electromagnetic steel sheets 32 are arranged so that portions of magnets 35 overlap with magnets 35 when viewed in the axial direction. For this reason, the axial end faces of magnets 35 are not covered by electromagnetic steel sheets 32 and are prevented from protruding from rotor core 33.

[0042] The magnet 35 has a generally square plate shape with a cross section perpendicular to the longitudinal direction (axial direction) that is nearly rectangular. Alternatively, multiple magnets 35 may be arranged in the slots 34, with gaps 35a formed between adjacent magnets 35 filled with a resin member 36. The magnets 35 are fixed to the rotor core 33 by the resin member 36 filled in the slots 34. The magnets 35 may be permanent magnets. The magnets 35 are rod-shaped hard magnetic bodies made by sintering powder of, for example, ferrite or neodymium, and may not be magnetized before being accommodated in the slots 34, but may be magnetized after being fixed to the rotor core 33.

[0043] Protrusions 31a and 32a that protrude toward the center are formed on the outer periphery of central hole 33a in electromagnetic steel plates 31 and 32. Protrusions 31a and 32a are provided in two locations symmetrically about the center of central hole 33a. Protrusions 31a and 32a are formed as a substantially rectangular outline extending from the outer periphery of central hole 33a.

[0044] As in the first embodiment, two axial grooves 21 extending in the axial direction are formed on the outer periphery of the shaft 20. The number of axial grooves 21 is set to correspond to the number of protrusions 31a, 32a. The cross-sectional shape of the axial grooves 21 corresponds to the contour shapes of the protrusions 31a, 32a. The axial grooves 21 allow the protrusions 31a, 32a to slide in the axial direction of the shaft 20. The shaft 20 is assembled so that when it is inserted into the central holes 33a of the electromagnetic steel plates 31, 32, the protrusions 31a, 32a move axially inside the axial grooves 21.

[0045] As shown in FIG. 4 of the first embodiment, circumferential grooves 22 extending in the circumferential direction are connected to the axial grooves 21 on the outer periphery of the shaft 20. The circumferential grooves 22 are formed at axial positions corresponding to the outermost electromagnetic steel sheets 32 when the rotor core 33 is attached to the shaft 20. The circumferential grooves 22 have a circumferential length corresponding to the length for rotating and fixing the outermost electromagnetic steel sheets 32 around the axis so as to be in a predetermined phase with respect to the inner electromagnetic steel sheets 31. In other words, by abutting the protruding portions 32a against the circumferential ends 22a of the circumferential grooves 22, it is possible to set the position of the outermost electromagnetic steel sheets 32 that are to be rotated around the axis and fixed so as to be in a predetermined phase with respect to the inner electromagnetic steel sheets 31.

[0046] In the rotor 30 of the motor of this embodiment, thin electromagnetic steel plates are press-formed to form electromagnetic steel plates 31 and 32. At this time, electromagnetic steel plates 31 and 32 are molded to have the same shape. That is, slots 34 and 37, through holes 34a and 37a, center hole 33a, and protrusions 31a and 32a are all formed to have the same shape and in the same positions. Then, in the lamination process, multiple electromagnetic steel plates 31 are stacked in the thickness direction, and magnets 35 are inserted into the formed slots 34 and fixed with resin members 36.

[0047] Furthermore, the electromagnetic steel plates 32 are aligned on both outer sides of the stacked electromagnetic steel plates 31 so that the slots 34 and 37, the through holes 34a and 37a, the central hole 33a, and the protrusions 31a and 32a are in the same positions, and the shaft 20 is inserted into the central hole 33a so that the protrusions 31a and 32a are aligned with the axial grooves 21. Next, when the electromagnetic steel sheet 32 ​​has moved to an axial position corresponding to the circumferential groove 22, the electromagnetic steel sheet 32 ​​is rotated along the circumferential groove 22. When the protrusion 32 a comes into contact with the circumferential end 22 a, the electromagnetic steel sheet 32 ​​is set to the attachment position, and the electromagnetic steel sheets 31 and 32 are fixed by a fixture or the like (not shown).

[0048] According to the motor rotor 30 of this embodiment, the axially outermost electromagnetic steel sheet 32 ​​has the same shape as the inner electromagnetic steel sheet 31, so there is no need to use different press dies or complicate the dies. As a result, only one type of die is required and the number of press steps using different dies can be reduced, resulting in a reduction in the number of steps and low-cost manufacturing.

[0049] Furthermore, by fixing the outermost electromagnetic steel sheet 32 ​​out of phase with the electromagnetic steel sheets 31 stacked on the inside, the inner magnet 35 and the magnet insertion hole 37 of the outermost electromagnetic steel sheet 32 ​​are positioned to overlap when viewed in the axial direction. This makes it possible to prevent the magnet 35 from falling off. At the same time, because part of the magnet 35 can be exposed from the magnet insertion hole 37 of the outermost electromagnetic steel sheet 32, the cooling performance of the magnet 35 can be improved.

[0050] According to the rotor 30 of the motor of this embodiment, the magnet insertion holes 34 of the inner electromagnetic steel plate 31 are exposed from the slots 37 of the outermost electromagnetic steel plate 32 when viewed in the axial direction. Therefore, even if foreign matter gets into the magnet insertion holes 34, the foreign matter can be expelled from the slots 37 of the outermost electromagnetic steel plate 32 to the outside of the rotor core 33. For example, foreign matter that has adhered to the outer wall due to the centrifugal force of the rotation of the rotor core 33 can be expelled by changes in the rotation speed of the rotor core 33. Examples of foreign matter include dust, moisture due to condensation, and motor wear powder. Furthermore, although the above-mentioned foreign matter is likely to become trapped in the gaps 35a formed between the magnets 35, the fact that these gaps 35a are exposed from the slots 37, which are through holes in the outermost electromagnetic steel plate 32, makes it easier for the foreign matter to be expelled to the outside of the rotor core 33.

[0051] According to the rotor 30 of the motor of this embodiment, the axial grooves 21 and the circumferential grooves 22 are provided on the outer peripheral surface of the shaft 20, so that the electromagnetic steel plates 31, 32 are fixed to the shaft 20 without misalignment. Furthermore, the circumferential groove 22 is provided on the outer peripheral surface of the shaft 20 at a position corresponding to the outermost electromagnetic steel plate (end plate) 32 in the axial direction. Therefore, when attaching the electromagnetic steel plates 31, 32 to the shaft 20, simply by rotating the electromagnetic steel plate 32 along the circumferential groove 22, the electromagnetic steel plate 32 can be easily fixed with a phase shift relative to the inner electromagnetic steel plate 11 whose protrusions 31 a are fitted in the axial grooves 21.

[0052] According to the rotor 30 of the motor of this embodiment, the circumferential length of the circumferential groove 22 is formed to be equal to the length corresponding to the phase by which the outermost electromagnetic steel plate 32 is shifted relative to the inner electromagnetic steel plate 31. Therefore, simply by abutting the protrusion 32a against the end 22a of the circumferential groove 22, it is possible to easily position the outermost electromagnetic steel plate 32 relative to the inner electromagnetic steel plate 31.

[0053] According to the motor rotor 30 of this embodiment, it is possible to achieve the effect that the number of manufacturing steps can be reduced and the number of parts required for manufacturing can be reduced.

[0054] In this embodiment, the following configuration is also possible. 4, in addition to the axial groove 21, the shaft 20 may be provided with another axial groove 23 that is provided along the axial direction at a circumferentially different position from the axial groove 21. In this case, as in the configuration described above, the protrusions 11a, 31a are fitted into the axial groove 21, and the protrusions 12a, 32a of the electromagnetic steel sheets 12, 32 that are shifted in phase in advance are fitted into the other axial groove 23. In this case, the shaft 20 may be provided with only the axial groove 21 and the other axial groove 23, without the circumferential groove 22. The other axial groove 23 may be formed in a shape corresponding to the position where the protrusions 12a, 32a rotated along the circumferential groove 22 to the end 22a are fixed.

[0055] This provides axial groove 21 and another axial groove 23, thereby preventing misalignment between electromagnetic steel plates 11, 12 and shaft 20. Furthermore, since shaft 20 has another axial groove 23 that fits with protruding portions 12a, 32a of outer electromagnetic steel plates (end face plates) 12, 32, by fitting protruding portions 11a, 31a of electromagnetic steel plates 11, 31 into axial groove 21 and shifting end face plates 12, 32 to fit protruding portions 11a, 31a into the other axial groove 23, it is possible to easily shift the phase of electromagnetic steel plates 12, 32 relative to inner electromagnetic steel plates 11, 31 and fix them.

[0056] Furthermore, other axial grooves 23 can be formed in the end plates 12, 32 that are both ends of the rotor cores 13, 33 in the axial direction. In this case, it is possible to form one other axial groove 23 on each side of the axial groove 21 in the circumferential direction. Also, the two other axial grooves 23 can be formed to have different axial lengths so that they have end positions that correspond to the fixing positions of the end plates 12, 32 that are both ends of the rotor cores 13, 33 in the axial direction (not shown).

[0057] Alternatively, the shaft 20 may be provided with only the axial grooves 21, without the circumferential grooves 22. In this case, the outermost electromagnetic steel plates 12, 32 are not provided with the protrusions 12a, 32a, and the contour shape of the central holes 13a, 33a can be a circular contour corresponding to the outer peripheral surface of the shaft 20.

[0058] This provides axial grooves 21, thereby preventing misalignment between electromagnetic steel plates 11, 31 and shaft 20. Furthermore, since protrusions 12a, 32a are not provided on outermost electromagnetic steel plates (end plates) 12, 32, when assembling inner electromagnetic steel plates 11, 31 to shaft 20, protrusions 12a, 32a do not get in the way, and end plates 12, 32 can easily be fixed with a phase shift relative to inner electromagnetic steel plates 11, 31 in the axial direction. [Explanation of symbols]

[0059] 10,30...Rotor 11,31...Electromagnetic steel plate (steel plate) 12,32...Electromagnetic steel plate (steel plate; end plate) 11a, 12a, 31a, 32a...protrusion 13,33...Rotor core 13a,33a...center hole 14, 17, 34, 37...Slots (magnet insertion holes) 14a, 14b, 17a, 17b, 34a, 37a...Through hole 15,35...Magnet 15a, 35a...gap 16, 36...Resin material 20...shaft 21...Axial groove 22…Circumferential groove 22a...end

Claims

1. A shaft, a rotor core formed by laminating a plurality of steel plates in the axial direction and having magnet insertion holes; A magnet to be inserted into the magnet insertion hole; a resin member filled in the magnet insertion hole to fix the magnet in the magnet insertion hole, At least one of the steel plates located at the outermost position in the axial direction among the plurality of steel plates has the same shape as other steel plates located at the inner position in the axial direction and is fixed with a phase shift around the axis, The plurality of steel plates each have a protruding portion protruding radially inward with respect to the shaft, The shaft has an axial groove along the axial direction into which the protruding portion is fitted, and a circumferential groove extending in the circumferential direction from the axial groove is formed at a position where the protruding portion of the steel plate located at the outermost side in the axial direction of the shaft is fixed. Motor rotor.

2. The steel plate is provided with a through hole, The steel plate is fixed in a state in which at least a part of the magnet insertion hole of the other steel plate located on the inner side in the axial direction is exposed from the through hole of the steel plate located on the outermost side in the axial direction. A rotor for a motor according to claim 1.

3. In one of the magnet insertion holes, a plurality of magnets are arranged side by side on a plane of the steel plate, The magnets are fixed in a state where the gaps between the magnets arranged side by side are exposed from the through holes of the steel plates located at the outermost positions in the axial direction. A rotor for a motor according to claim 2.

4. The circumferential length of the circumferential groove is set to be equal to a dimension by which the protrusion moves in the circumferential direction in response to a phase around the axis that fixes the steel plate located at the outermost position in the axial direction. A rotor for a motor according to any one of claims 1 to 3.

5. The plurality of steel plates each have a protruding portion protruding radially inward with respect to the shaft, The shaft is an axial groove provided along the axial direction and adapted to engage with the protruding portion; The axial groove is provided along the axial direction at a different position in the circumferential direction, and another axial groove is fitted with the protruding portion of the steel plate located at the outermost position in the axial direction; having A rotor for a motor according to any one of claims 1 to 4.

6. The rotor core has a plurality of magnet insertion holes, The plurality of magnet insertion holes are arranged adjacent to each other in a circumferential direction of the steel plate so as to have a constant phase, A space between two of the magnet insertion holes adjacent to each other in the circumferential direction overlaps with the magnet when viewed in the axial direction. A rotor for a motor according to any one of claims 1 to 5.

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