Core and rotor using the same

Abstract

To provide a core which facilitates insertion work of a key into a key groove.SOLUTION: The core 3 includes a core body 4 in which a plurality of annular iron core pieces 9 are laminated in the axial direction, a key 11 projected in the radial direction from the inner periphery of the core body 4, and a recess 19 in the radial direction which is provided in a part of the key 11 in the axial direction and extends over the entire width direction of the key 11.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a core used in a rotating electrical machine and a rotor using the core. [Background technology]

[0002] A conventional rotary electric core is used in a rotor described in Patent Document 1.

[0003] The rotor has a core made of multiple annular electromagnetic steel plates stacked in the axial direction, and a key protruding radially from the inner periphery of the core, which engages with a key groove in the shaft when the core is attached to the shaft.

[0004] The core of such a rotor has a cutout so that the key can open at its tip. A hole is connected to the cutout, and when a pin is pressed into the hole, the key opens at its tip and engages with the key groove in the shaft.

[0005] Therefore, the conventional core allows the key to be smoothly inserted into the key groove and has high reliability.

[0006] However, with the above-mentioned conventional core, although the key itself can be smoothly inserted into the key groove, the pin must be inserted into the hole, which makes the overall insertion process complicated. In other words, with the conventional core, it was not easy to insert the key into the key groove. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-181270 Summary of the Invention [Problem to be solved by the invention]

[0008] The problem to be solved is that it is not easy to insert the key into the key groove. [Means for solving the problem]

[0009] The present invention provides a core comprising a core body in which a plurality of annular iron core pieces are stacked in the axial direction, a key protruding radially from the inner or outer circumference of the core body piece, and a radial recess provided in a portion of the key in the axial direction and spanning the entire width of the key.

[0010] The present invention also provides a rotor using the above-described core, comprising a shaft that fits onto the inner periphery of the core and a key groove formed in the shaft, wherein the core has a key provided on the inner periphery that engages with the key groove. [Effects of the Invention]

[0011] The present invention allows the key to be easily inserted into the key groove. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic plan view of a rotor using a core according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the rotor taken along line II-II of FIG. [Figure 3] 3 is a front view of the periphery of the key of the rotor core of FIG. 1 as viewed from the inside in the radial direction. [Figure 4] FIG. 4 is a plan view showing the key of FIG. [Figure 5] FIG. 5 is a plan view showing a key of a core according to a modified example of the first embodiment. [Figure 6] FIG. 6 is a plan view showing a key of a core according to another modified example of the first embodiment. [Figure 7] FIG. 7 is a plan view showing a key of a core according to still another modified example of the first embodiment. [Figure 8]FIG. 8 is a front view of the periphery of a key of a core used in a rotor according to a second embodiment of the present invention, as viewed from the inside in the radial direction. [Figure 9] FIG. 9 is a front view of the periphery of a key of a core used in a rotor according to a modified example of the second embodiment, viewed from the inside in the radial direction. [Figure 10] FIG. 10 is a cross-sectional view showing a part of a rotor using a core according to a third embodiment of the present invention. [Figure 11] FIG. 11 is a plan view of a core used in a stator according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] The purpose of facilitating insertion of the key into the key groove is achieved by providing a radial recess in a portion of the axial direction of the key.

[0014] The core 3 includes a core body 4, a key 11, and a recess 19. The core body 4 is formed by stacking a plurality of annular core pieces 9 in the axial direction. The key 11 protrudes radially from the inner or outer periphery of the core body 4. The recess 19 is a radial recess that is provided in a portion of the axial direction of the key 11 and spans the entire width of the key 11.

[0015] The key 11 may be a key piece provided on a part of the plurality of core pieces 9. In this case, the recess 19 is made up of a keyless portion where there is no key piece 12 that engages with the key groove 13 of the shaft 7, or a secondary key piece 14 that has a larger radial gap between it and the key groove 13 than the key piece 12.

[0016] The recesses 19 may be provided at predetermined intervals among the plurality of core pieces 9 .

[0017] The recesses 19 may be arranged only in the axial end regions of the key 11 .

[0018] The key 11 may be provided with a slit 21 and may be divided in the width direction by the slit 21. In this case, the slit 21 may be disposed adjacent to the end side of the recess 19 in the axial direction.

[0019] The width of the key 11 may gradually narrow towards the axial end.

[0020] A rotor 1 using the core 3 includes, in addition to the core 3, a shaft 7 and a key groove 13. The shaft 7 is fitted to the inner periphery of the core 3. The key groove 13 is formed in the shaft 7. The core 3 has a key 11 provided on the inner periphery, and the key 11 engages with the key groove 13. [Example]

[0021] [Rotor and core] Fig. 1 is a schematic plan view of a rotor according to a first embodiment of the present invention. Fig. 2 is a cross-sectional view of the rotor taken along line II-II of Fig. 1. Fig. 3 is a front view of the periphery of a key of the core of the rotor of Fig. 1 as seen from the inside in the radial direction. Fig. 4 is a plan view showing the key of Fig. 2. In the following description, the axial direction, radial direction, and circumferential direction refer to the axial direction, radial direction, and circumferential direction of the core, respectively.

[0022] As shown in FIG. 1, the rotor 1 includes a core 3 and a shaft 7 , and the shaft 7 is fitted into a central hole 5 that defines the inner periphery of the core 3 .

[0023] The core 3 in this embodiment is a rotor core, but can also be configured as a stator core. This core 3 includes a core body 4. As shown in Figures 1 to 3, the core body 4 is configured into a cylindrical shape by stacking a plurality of annular core pieces 9, which are electromagnetic steel plates, in the axial direction. The plurality of core pieces 9 of the core body 4 are integrated with each other by an appropriate method such as crimping.

[0024] 2 and 3, the core 3 is shown as being made up of nine laminated core pieces 9a to 9i for ease of understanding. In reality, the core 3 is made up of an appropriate number of laminated core pieces 9 depending on the specifications of the rotor 1, etc.

[0025] The core 3 has a central hole 5 defining the inner periphery, as well as magnet holes 15 and the like that penetrate the core 3 in the axial direction. A permanent magnet 17 is fixed in the magnet hole 15.

[0026] The central hole 5 is formed by axially connecting circular holes formed in the centers of multiple core pieces 9. A key 11 is provided to protrude radially from the inner periphery of the core 3 defined by the central hole 5.

[0027] 1 to 4, the key 11 is generally columnar and provided along the axial direction of the core body 4. The key 11 of this embodiment engages with a key groove 13 of the shaft 7 that constitutes the rotor 1 together with the core 3. The radial tip of the key 11 faces toward the center of the central hole 5, and engages with the key groove 13 of the shaft 7 in the circumferential direction.

[0028] The key 11 may be one that engages with a key groove of a shaft for stacking the blocks. A block is formed by stacking and integrating a plurality of core pieces 9. In this case, the core 3 is formed by stacking and integrating a plurality of blocks. When stacking a plurality of blocks, the key 11 of each block engages with a key groove of the shaft for stacking the blocks.

[0029] In this embodiment, the key 11 is made up of key pieces 12 provided on some of the multiple core pieces 9. As a result, the key 11 has a radial recess 19 that is provided on part of the axial direction and that spans the entire width direction.

[0030] Specifically, the key pieces 12 are provided at predetermined intervals (every other key piece in this embodiment) with respect to the plurality of core pieces 9 in the axial end region of the key 11. The intervals between the key pieces 12 can be set arbitrarily, and for example, they may be provided every third key piece. In Figures 2 and 3, the key pieces 12 are provided on the first layer 9a, the third layer 9c, the fifth layer 9e, and the seventh to ninth layers 9g to 9h of the core pieces 9.

[0031] The end region is an end region that is forward in the insertion direction relative to the key groove 13. The axial range of the end region is set to a predetermined range from the first layer 9a, which is one end of the core 3, taking into consideration ease of insertion, etc. The end region may be an end region on both sides of the key 11 in the axial direction.

[0032] Due to such an arrangement of the key pieces 12, the recess 19 of this embodiment is configured as a keyless portion in which there are no key pieces 12 that engage with the key grooves 13 of the shaft 7. In other words, the recess 19 is configured by thinning out the key pieces 12.

[0033] The recesses 19 may be formed so as to extend radially toward the core body 4. The recesses 19 may also be formed by reducing the plate thickness of the key pieces 12, rather than by thinning out the key pieces.

[0034] In this embodiment, the recesses 19 are defined in the second layer 9b, the fourth layer 9d, and the sixth layer 9f of the core piece 9. As a result, the recesses 19 are formed only in the axial end regions of the key 11. The holes of the core pieces 9 in the second layer 9b, the fourth layer 9d, and the sixth layer 9f that form the center hole 5 are simply circular.

[0035] The planar shape of the key 11 and the key piece 12 is rectangular as a whole, and is divided in the width direction by a slit 21. The width direction of the key 11 is a tangential direction to the center hole 5, but it may also be a circumferential direction.

[0036] This key 11 has a tip edge 11a and side edge 11b. The tip edge 11a is located at the radial tip (inner end) and is formed in a straight line along the tangential direction of the center hole 5. The tip edge 11a can also be formed as an arc with the same curvature as the curvature of the center hole 5. The side edge 11b is located on both sides in the width direction and is formed parallel to the radial direction.

[0037] In this embodiment, the slits 21 are provided only in the end regions of the key pieces 12. As a result, the slits 21 are disposed adjacent to the recesses 19 on the end side in the axial direction.

[0038] The slit 21 is located at the center in the width direction of the key piece 12 and extends radially outward from the tip edge 11a in the radial direction. A bottom portion 21a of the slit 21 has an arc shape in a plan view.

[0039] In this embodiment, the width of the slit 21 is set to be slightly smaller than one-third the width of the key 11. The length of the slit 21 is at least twice the protruding length of the key 11. However, the width, length, position, and shape of the slit 21, as well as the key piece 12 on which the slit 21 is provided, can be set as appropriate as long as the function of the key 11 is maintained. For example, the length of the slit 21 may be set so that the slit 21 is positioned within the range of the protruding length of the key 11.

[0040] The shaft 7 is formed in a cylindrical shape corresponding to the center hole 5 of the core 3. A key groove 13 is formed on the outer peripheral surface of the shaft 7 along the axial direction. The shape of the key groove 13 corresponds to the key 11 and engages with the key 11 in the width direction. That is, the key groove 13 has an inner surface 13a in the width direction that engages with the side edge portion 11b of the key 11. Note that a shaft for block stacking can also be configured in the same way as the shaft 7.

[0041] [Shaft Insertion] The shaft 7 is inserted axially into the central hole 5 from one end (upper end in Fig. 2) of the core 3 in Fig. 2. At this time, as the shaft 7 moves relatively toward the other axial end (lower end in Fig. 2) of the core 3, the key grooves 13 engage with the keys 11 in the order of the first layer 9a, the third layer 9c, the fifth layer 9e, the seventh layer 9g, the eighth layer 9h, and the ninth layer 9i.

[0042] When the key 11 engages with the key groove 13, the side edge 11b of the key 11 may slide against the circumferential inner surface 13a of the key groove 13. This is because it is difficult to position all of the key pieces 12 of the multiple core pieces 9 in their designed positions due to tolerances and the like, and some or all of the key pieces 12 may become misaligned in the circumferential direction.

[0043] FIG. 3 shows, as an example, a state in which the key pieces 12 on the first layer 9a and the third layer 9c are misaligned with respect to the key pieces 12 on the fifth layer 9e and the seventh to ninth layers 9g to 9i that are positioned accurately in the designed positions.

[0044] During this sliding movement, the portion of the key 11 adjacent to the recess 19 in the axial direction, i.e., the key piece 12 adjacent to the recess 19 in the axial direction, is allowed to flex so as to enter the recess 19 on both circumferential sides. Furthermore, the key 11 does not come into contact with the key groove 13 at the recess 19.

[0045] 3, for example, the left side edge 11b of the first layer 9a and the third layer 9c in FIG. 2 slides against one inner surface 13a of the key groove 13, and the right side edge 11b of the fifth layer 9e slides against the other inner surface 13a of the key groove 13. The sliding resistance of the key piece 12 causes the sliding portion to bend into the recess 19.

[0046] 3. Furthermore, the key 11 does not contact the key groove 13 in the second layer 9b, the fourth layer 9d, and the sixth layer 9f in FIG.

[0047] Therefore, the sliding resistance of the key 11 to the key groove 13 is reduced, and the key 11 can be easily inserted into the key groove 13 .

[0048] Furthermore, when the key 11 slides in the key groove 13, the portion of the key 11 where the slit 21 is provided (the key piece 12) is allowed to bend in the width direction by the slit 21.

[0049] For example, in Figures 3 and 4, when the side edge portions 11b of the first layer 9a, the third layer 9c, and the fifth layer 9e slide against the inner surface 13a of the key groove 13, this sliding presses the key piece 12 in the circumferential direction, causing it to bend so as to shrink the slit 21.

[0050] Therefore, the sliding resistance of the key 11 to the key groove 13 is reduced, and the key 11 can be inserted into the key groove 13 more easily.

[0051] In this way, in this embodiment, the provision of the recess 19 allows deflection of both circumferential side portions of the key 11. Therefore, even if part or all of the key pieces 12 are displaced in the circumferential direction, the key 11 can be easily and reliably inserted into the key groove 13. As a result, it is possible to prevent the shaft 7 from becoming unable to be inserted into the center hole 5 of the core 3 midway.

[0052] In this embodiment, each recess 19 is provided across the entire width of the key 11. Therefore, when the key piece 12 bends into the recess 19, the bending is sufficiently tolerated and the key piece 12 is less likely to be damaged.

[0053] Furthermore, in this embodiment, the axial bending of both widthwise sides of the key 11 allows the key 11 to reliably engage with the key groove 13 in the widthwise direction. Therefore, there is no need to attach a pin or the like after inserting the key 11 into the key groove 13, and the insertion work can be carried out easily.

[0054] Furthermore, in this embodiment, the recess 19 is provided only in the end region of the key 11, so that in other parts, the deflection of the key 11 is suppressed, and engagement with the key groove 13 in the width direction can be reliably performed while maintaining rigidity.

[0055] Furthermore, the key 11 of this embodiment is made up of key pieces 12 provided on some of the multiple core pieces 9, which makes it easy to define the recesses 19. Furthermore, since the key pieces 12 are provided on every other core piece 9, the key 11 can be inserted into the key grooves 13 more easily and reliably.

[0056] [Variations] 5 to 7 are plan views showing keys of cores according to modifications of the first embodiment.

[0057] In each of the modifications shown in FIGS. 5 to 7, the shape of the slit 21 is changed from that of the first embodiment.

[0058] In the modified example shown in Fig. 5, the bottom portion 21b of the slit 21 is a circular hole. In the modified example shown in Fig. 6, the slit 21 is short and gradually widens toward the tip edge 11a. In the modified example shown in Fig. 7, the slit 21 is set inside the key 11, and the slit 21 has a bottom portion 21c formed by a circumferentially elongated hole.

[0059] Even if the slit 21 is changed in this way, the same effects as those of the first embodiment can be achieved. [Example]

[0060] 8 is a front view of the periphery of a key of a core used in a rotor according to a second embodiment of the present invention, viewed from the inside in the radial direction. Note that the basic configuration of the second embodiment is the same as that of the first embodiment, and the same reference numerals are used to designate the same or corresponding components as those of the first embodiment, and redundant explanations will be omitted.

[0061] As shown in FIG. 8, in the core 3 of Example 2, the width of the keys 11 narrows gradually or in steps toward the keys 11 of the first layer 9a, which is the axial end located forward in the insertion direction.

[0062] In other words, the keys 11 on the fifth layer 9e are the same width as the keys 11 on the seventh layer 9g to the ninth layer 9i, the keys 11 on the third layer 9c are narrower than the keys 11 on the fifth layer 9e, and the keys 11 on the first layer 9a are narrower than the keys 11 on the third layer 9c.

[0063] The widths between the first layer 9a, the third layer 9c, and the fifth layer 9e are set to be narrower at a certain ratio, but it is not necessary to set a particular ratio.

[0064] Therefore, in this embodiment, the key 11 can be more easily fitted into the key groove 13. In addition, the second embodiment can also achieve the same effects as the first embodiment.

[0065] FIG. 9 is a front view of the periphery of a key of a core used in a rotor according to a modified example of the second embodiment, viewed from the inside in the radial direction.

[0066] In the modification of Fig. 9, the key pieces 12 of the first layer 9a, the third layer 9c, and the fifth layer 9e are provided with slits 21. The planar shape of the slits 21 may be any of the shapes shown in Figs. 4 to 7 or other shapes.

[0067] In this modified example, the same effects as in the second embodiment can be obtained, and the slit 21 improves the ease of insertion as in the first embodiment. [Example]

[0068] 10 is a radial cross-sectional view showing a part of a rotor core according to a third embodiment of the present invention. In the third embodiment, the basic configuration is the same as in the first embodiment, and the same reference numerals are used to designate the same or corresponding components as in the first embodiment, and redundant explanations will be omitted. The cross section in FIG. 10 corresponds to the cross section in FIG. 2.

[0069] As shown in Figure 10, in the core 3 of Example 3, the recess 19 is defined by a secondary key piece 14. The secondary key piece 14 is formed to be shorter in the radial direction than the key piece 12 of the key 11, and forms a larger radial gap with respect to the key groove 13 than between the key piece 12 and the key groove 13. The radial length of the secondary key piece 14 may be shorter than the radial length of the key piece 12, but is preferably less than 50% of the radial length of the key piece 12. The rest is the same as in Example 1.

[0070] In the third embodiment, the same effects as those of the first embodiment can be achieved. [Example]

[0071] Fig. 11 is a plan view of a core used in a stator according to a fourth embodiment of the present invention. In the fourth embodiment, the basic configuration is the same as that of the first embodiment, and the same reference numerals are used to designate the same or corresponding components as those in the first embodiment, and redundant explanations will be omitted. The cross section of Fig. 12 corresponds to the cross section of Fig. 2.

[0072] The core 3 of this embodiment is formed as a stator core. This core 3 is formed in a cylindrical shape. A plurality of slots 23 are provided at intervals in the circumferential direction on the inner periphery of the core 3. Keys 11 are provided on the outer periphery of the core 3.

[0073] The key 11 is configured in the same manner as in Example 1. Therefore, for the cross-sectional shape of the key 11, refer to Figure 2. That is, in the cross-sectional shape of the key 11, recesses 19 formed by thinning out the key pieces 12 are defined in the second layer 9b, the fourth layer 9d, and the sixth layer 9f. Key pieces 12 are provided in the other layers.

[0074] The planar shape of the key 11 may be the same as that of either the first embodiment or its modified example, or may be a different shape, and may also be a simple rectangular shape as shown in Figure 11. Also, the key 11 may have a recess 19 defined by a secondary key piece 14, as in the third embodiment.

[0075] In the fourth embodiment, the same effects as those of the first embodiment can be achieved when inserting the core 3 into the case (frame). [Explanation of symbols]

[0076] 1 rotor 3 cores 5 Center hole 7 shaft 9 Core pieces 11 keys 11a Tip edge 11b Side edge 13 Keyway 19 Recess 21 Slit

Claims

1. a core body in which a plurality of annular core pieces are stacked in the axial direction; a key provided to protrude radially from an inner periphery or an outer periphery of the core body; a radial recess provided at a portion of the key in the axial direction and extending across the entire width of the key; Core with.

2. 10. The core of claim 1, The key is made of a key piece provided on a part of the plurality of core pieces. core.

3. 3. The core of claim 2, The recess is defined by a keyless portion having no key piece that engages with the key groove of the shaft, or by a secondary key piece that has a radial gap between the key groove and the secondary key piece that is larger than the key piece. core.

4. 4. The core of claim 2 or 3, The recesses are provided at predetermined intervals among the plurality of core pieces, core.

5. The core according to any one of claims 1 to 3, the recesses are disposed only in the axial end regions of the keys; core.

6. The core according to any one of claims 1 to 3, The key has a slit in at least a part of the axial direction and is divided in the width direction by the slit. core.

7. 7. The core of claim 6, The slit is disposed adjacent to the end side of the recess in the axial direction. core.

8. The core according to any one of claims 1 to 3, The key has a gradually narrowing width toward the axial end. core.

9. A rotor using the core according to any one of claims 1 to 3, a shaft fitted to the inner periphery of the core; a keyway formed in the shaft; The core has the key provided on the inner periphery, and the key engaged with the key groove. rotor.

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