Rotor

Abstract

To provide a rotor that can seal leakage of a resin without providing a separate component.SOLUTION: A rotor that rotates around a rotational shaft and has a predetermined length in an axis direction, includes: a rotor core with a plurality of salient electrodes that are adjacent to each other in a circumferential direction and slots formed between the adjacent salient electrodes; a rotor coil wound on the salient electrodes through the slots; an end cover that covers both ends of the rotor core in the axis direction; a wedge that fills a gap between the salient electrodes on which the rotor coil is wound. The wedge includes a projection part that projects to the end cover side from both ends of the rotor core in the axis direction and is crushed by the end cover. In the axis direction, both ends of the wedge and both ends of the rotor core makes contact with the end cover when the projection part is crushed by the end cover.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] Patent Document 1 describes a wound-field type rotating electric machine having a rotor including a rotor core on which salient poles are formed at predetermined intervals in the circumferential direction, coils wound around the salient poles and functioning as electromagnets, and an interpole member connecting between the salient poles adjacent in the circumferential direction. In the rotor of the rotating electric machine described in Patent Document 1, resin is molded between the salient poles adjacent in the circumferential direction and the interpole member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-121108 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the rotor of Patent Document 1, the interpole member, the coil, and the rotor core are fixed by molding resin between the salient pole portion and the interpole member. In Patent Document 1, it is assumed that the resin is molded in a state in which both axial ends of the rotor core (20) are covered with end covers (40) as cover members, as shown in FIG. 4, for example. However, if the interpole member (50) has a sink mark (S) or the lamination thickness of the rotor core (20) varies greatly, it is considered that the axial end face of the rotor core (20) and the axial end face of the interpole member are not located at a predetermined design position in the axial direction. In such a state, if the end cover (40) is attached to the rotor core (20) to which the interpole member (50) is attached, a gap (not shown) is generated between the end cover (40) and the interpole member (50) in the axial direction, and the resin used in molding may leak out from the gap toward the radial outside of the rotor core (20). For such leakage, it is expected that the leakage will be sealed by adding a new part such as a gasket, but adding a part to seal the leakage will increase the cost of the part. Therefore, it is desirable to develop a method for sealing the resin leakage without adding a new part.

[0005] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a rotor that is capable of sealing resin leakage without providing any new parts. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, a rotor that rotates around a rotation axis and has a predetermined length in the axial direction comprises a rotor core having a plurality of salient poles adjacent in the circumferential direction and slots formed between the adjacent salient poles, a rotor coil wound around the salient poles through the slots, end covers covering both ends of the rotor core in the axial direction, and wedges filling the gaps between the salient poles around which the rotor coil is wound, wherein the wedges protrude from both ends of the rotor core toward the end covers in the axial direction and have projections that are crushed by the end covers, and when the projections are crushed by the end covers in the axial direction, both ends of the wedges and both ends of the rotor core abut against the end covers.

[0007] That is, the rotor has a wedge between adjacent salient poles formed on the rotor core in the circumferential direction. The wedge has protruding portions that protrude from both ends of the rotor core toward the end cover in the axial direction and are crushed by the end cover. When the protruding portions are crushed by the end cover, both ends of the wedge and both ends of the rotor core abut against the end cover. That is, since the length of the wedge is longer than the rotor core by the amount that it protrudes toward the end cover in the axial direction, when both ends of the rotor core are covered with the end cover, the wedge with a longer dimension in the axial direction is crushed by the inner surface of the end cover, and the dimensional difference between the wedge and the rotor core is absorbed. Then, by absorbing the dimensional difference, the inner surface of the end cover abuts against both ends of the wedge and both ends of the rotor core and is in close contact with each other. That is, in the axial direction, a seal is formed between the end cover, the wedge, and the rotor core. This makes it possible to seal the resin leakage in the axial direction, and as a result, it is possible to prevent the occurrence of gaps (gaps in the axial direction) between the end cover and the wedge (and the rotor core). By preventing the occurrence of gaps in the axial direction in this way, it is possible to prevent the resin from leaking outward in the radial direction of the rotor core. Therefore, for example, there is no need to provide a new part such as a gasket to absorb the above-mentioned dimensional difference, and as a result, it is possible to avoid an increase in the number of parts and the part costs when constructing the rotor (in other words, it is possible to reduce the number of parts and the part costs when constructing the rotor). [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a schematic diagram of a rotor according to the present embodiment. [Diagram 2] FIG. 2 is a view of the rotor as viewed from the axial direction. [Diagram 3] FIG. 3A is an enlarged view of a portion of the rotor in FIG. 2, FIG. 3B is a view for explaining a wedge, FIG. 3C is a view for explaining an example of a protrusion, and FIG. 3D is a view for explaining another example of a protrusion. [Figure 4] FIG. 1 is a reference diagram for explaining a problem. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Here, an embodiment of the present invention will be described in the following order with reference to the drawings. Note that the embodiment described below is merely an example of the present invention and is not intended to limit the present invention. (1) Rotor configuration: (2) Other embodiments:

[0010] (1) Rotor configuration: FIG. 1 is a schematic diagram of a rotor 1 according to this embodiment. FIG. 2 is a diagram of the rotor 1 according to this embodiment as viewed from the axial direction. The rotor 1 shown in FIG. 1 and FIG. 2 constitutes a motor together with a stator (not shown) arranged concentrically on the radial outside of the rotor 1. For example, the rotor 1 is applied to a motor of an electric vehicle or a hybrid vehicle, and the motor functions as an electric motor that generates a driving force for running and also functions as a generator that generates electricity with regenerative torque. The stator is fixed to a casing (motor case), and the rotor 1 is rotatable relative to the stator. In this specification, the direction along the axis of the rotor 1 is referred to as the "axial direction," and the direction perpendicular to the axis (the radial direction of the rotor) is referred to as the "radial direction." In addition, the axis side in the radial direction is referred to as the "radial inner side," and the opposite side to the axis in the radial direction (the side away from the axis) is referred to as the "radial outer side." Furthermore, the direction along the circumference of a circle centered on the axis is referred to as the "circumferential direction."

[0011] The rotor 1 has, as its main components, a rotor shaft (rotating shaft) 10, a substantially cylindrical rotor core 20 that fits onto the outer circumferential surface of the rotor shaft 10 and has the rotor shaft 10 as its axis, a rotor coil 30 wound around a plurality of salient poles 21 formed on the outer circumferential side of the rotor core 20, end covers 40 that cover both ends of the rotor core 20, and wedges 50 that fill the gaps between the salient poles 21 around which the rotor coil 30 is wound. The rotor shaft 10 is, for example, a hollow shaft having a hollow portion, and is rotatably supported by a bearing member (neither of which is shown) relative to a casing.

[0012] The rotor core 20 is a substantially cylindrical member having a shaft hole at the center thereof, to which the rotor shaft 10 is fixed, and having a predetermined length in the axial direction. The rotor core 20 is made of a magnetic material, such as a laminate of a plurality of annular electromagnetic steel sheets formed by press working, or a powder magnetic core. The rotor core 20 includes a cylindrical back yoke (core body) 22 and a plurality of salient poles 21 protruding radially outward from the outer circumferential surface of the back yoke 22. The salient poles 21 are formed on the outer circumferential surface of the rotor core 20, aligned at regular intervals in the circumferential direction. A plurality of slots 23 are formed between the salient poles 21, which are spaces in which a portion of the rotor coil 30 is accommodated. Each slot 23 extends radially of the rotor core 20, and is aligned at regular intervals in the circumferential direction. The rotor coil 30 is wound around the salient poles 21, as shown in FIG. 2. In the example shown in FIG. 2, there are a plurality of salient poles 21, slots 23, rotor coils 30, and wedges 50 in the circumferential direction, but the reference numerals for each component are representatively drawn only one or two.

[0013] The rotor coil 30 is a field winding wound around the salient pole 21. The rotor coil 30 passes through the inside of a slot 23 formed between the salient poles 21 adjacent to each other in the circumferential direction and is wound around the salient pole 21 with a predetermined number of turns. More specifically, the radially outer end face of the salient pole 21 faces an end face of a stator core (more specifically, a stator tooth) in a stator not shown, and a magnetic circuit is formed between the salient pole 21 and both end faces of the stator core. The rotor coil 30 is wound around the salient pole 21 so as to interlink with the magnetic flux passing through the salient pole 21 and the stator core.

[0014] The end covers 40 are annular members that cover both ends of the rotor core 20 in the axial direction. The end covers 40 abut against both ends of the rotor core 20 in the axial direction, and the abutting inner surfaces of the end covers 40 and the axial end faces of the rotor core 20 are sealed by, for example, metal touch. In the example shown in Fig. 1, the diameter of the rotor core 20 is larger than the diameter of the end covers 40, and the end covers 40 do not cover the entirety of both ends of the rotor core 20. Therefore, the end covers 40 are not limited to a configuration that covers the entirety of both ends of the rotor core 20 in the axial direction, and may be a shape that covers part of them.

[0015] At least one end face of the end cover 40 in the axial direction is formed with a hole (not shown) for injecting resin into the slots 23. After the rotor shaft 10, rotor core 20, rotor coil 30, end cover 40, and wedge 50, which are the main components of the rotor shown in Figs. 1 and 2, are assembled, resin is injected from the hole to fix the rotor coil 30 wound around the salient pole 21 and ensure insulation between adjacent rotor coils 30. The end cover 40 also abuts against both ends of the wedge 50 in the axial direction, and the surface (inner surface) of the end cover 40 facing the protrusion 53 is, for example, flat, in consideration of ease of crushing the protrusions 53 formed on both ends of the wedge 50.

[0016] The wedges 50 are members that prevent the resin injected from the holes at the ends of the end cover 40 from leaking outward in the radial direction from between the salient poles 21 arranged in the circumferential direction. That is, the wedges 50 are members that fill the gaps at the ends of the salient poles 21 on the radially outer side. The wedges 50 have a predetermined length in the axial direction, similar to the rotor core 20, and are arranged between the salient poles 21 in the circumferential direction. That is, the wedges 50 are arranged discretely in the circumferential direction. The wedges 50 are formed by injection molding, for example, using resin as a material. The length relationship between the wedges 50 and the rotor core 20 in the axial direction will be described later.

[0017] 3A to 3D are diagrams for explaining the wedge 50 in this embodiment. FIG. 3A is an enlarged view of a part of the wedge arranged between the salient poles 21 adjacent in the circumferential direction. As shown in FIG. 3A, the wedge 50 is formed in a substantially "t" shape when viewed from the axial direction. Specifically, as shown in FIG. 3A and FIG. 3B, the wedge 50 has a beam portion 51 that extends in the circumferential direction and fills the gap between the salient poles 21 adjacent in the circumferential direction (or connects the salient poles 21), and a rib 52 that protrudes radially inward and outward from the beam portion 51 and fills the gap between the salient poles 21 adjacent in the circumferential direction. The rib 52 is composed of a first rib 52a that protrudes radially outward from the beam portion 51, and a second rib 52b that protrudes radially inward from the beam portion 51. In this embodiment, the first rib 52a has a circumferential thickness (wall thickness) d1, which is greater than the circumferential thickness d2 of the second rib 52b. The shape of the wedge 50 is determined according to the shape of the salient pole 21 adjacent to the wedge 50, or is a shape for fixing the wedge 50 with resin injected from a hole formed in the end face of the end cover 40. Alternatively, the shape is a shape for suppressing the occurrence of sink marks and the like that occur during injection molding.

[0018] In this way, by providing the wedge 50 between the salient poles 21 adjacent to each other in the circumferential direction, leakage of resin in the radial direction between the salient poles 21 can be sealed. On the other hand, since the wedge 50 and the rotor core 20 on which the salient poles 21 are formed are separate members, an unavoidable gap may be generated between them. For example, in the example shown in FIG. 3A, a small gap is generated between the second rib 52b and the salient poles 21 in the circumferential direction. There is a risk that resin may leak from this gap, for example, in the axial direction of the rotor 1. Specifically, as described above, the wedge 50 and the rotor core 20 have a predetermined length in the axial direction, but in a conventionally known rotor, for example, the rotor core is compressed by the clamping force in injection molding, and depending on the manner of compression, the lamination thickness of the rotor core varies. Depending on the variation in the lamination thickness, the length (total length) of the rotor core in the axial direction may not be slightly longer than the length of the wedge (in other words, the axial length of the wedge may be slightly shorter than the rotor core). That is, a dimensional difference occurs between the wedge and the rotor core. Both ends of rotor core 20 in the axial direction are sealed by end covers 40, but a gap is formed between both ends of wedge 50 and end cover 40 due to the dimensional difference between wedge 50 and rotor core 20, and resin may leak from this gap in the axial direction and even to the radially outer side of rotor core 20. Additionally, end cover 40 and rotor core 20 are sealed by metal touch as described above, but because wedge 50 is made of resin, even if there is no dimensional difference between wedge 50 and rotor core 20, resin may leak in the axial direction and ultimately to the radially outer side.

[0019] It is conceivable that such resin leakage can be prevented by, for example, providing a component such as a gasket to absorb the dimensional difference and seal the leakage, but providing a component to seal the leakage increases the component cost. Therefore, in this embodiment, in order to seal the resin leakage in the axial direction and radially outward without providing a component such as a gasket, the length of the wedge 50 in the axial direction is configured to be longer than the length of the rotor core 20.

[0020] 3C, in the axial direction, the wedges 50 protrude from both ends of the rotor core 20 toward the end cover 40, and the total length of the wedges 50 is longer than the total length of the rotor core 20 by the amount of protrusion. In this embodiment, the portions protruding toward the end cover 40 form protrusions 53, which are crushed by the inner surface of the end cover 40 when the rotor core 20 is covered with the end cover 40. The protrusions 53 are part of the wedges 50, and are integrally molded by injection molding.

[0021] The shape of the protrusion 53 may be any shape as long as it can seal the leakage of resin in the axial direction, but it is preferable that the shape is such that the protrusion 53 can be easily crushed when the end cover 40 crushes the protrusion 53, or that the load on the wedge 50 can be suppressed when the protrusion 53 is crushed. In the example shown in FIG. 3C, the shape of the protrusion 53 is a triangular cross section in a direction perpendicular to the circumferential direction (i.e., a cross section in the axial direction). This is because, when the protrusion 53 is crushed by the end cover 40, the contact area between the inner surface of the end cover 40 and the protrusion 53 can be made smaller than, for example, a rectangular protrusion. In this way, the small contact area between the inner surface of the end cover 40 and the protrusion 53 can suppress the load on the wedge 50. In addition, the shape of the protrusion 53 may be a semicircular cross section in a direction perpendicular to the circumferential direction of the protrusion 53, as shown in FIG. 3D. In this way, by making the shape of the protrusion 53 semicircular, when forming the wedge 53 by injection molding, for example, the number of edge portions is reduced compared to the above-mentioned triangular shape, making it easier to process and suppressing mold wear and cracks in the wedge 50.

[0022] In this embodiment, the range in which the protrusion 53 is provided is the circumferential range of the beam portion 51 as shown in Figs. 3A and 3B. That is, the protrusion 53 is provided so as to cross the surface extending in the circumferential direction of the wedge 50 as viewed from the axial direction. Specifically, the protrusion 53 is formed over the range of the beam portion 51 in the circumferential direction, and the range in which the protrusion 53 can be formed is indicated by a broken line R in Fig. 3B. This is because, as described above, there is a possibility that resin may leak from the gap between the second rib 52b and the salient pole 21 in the circumferential direction, and by providing the protrusion 53 in the range of the beam portion 51 having a larger circumferential thickness than the second rib 52b, leakage of resin in the axial direction can be prevented when the protrusion 53 is crushed by the end cover 40. That is, the injection pressure of the resin from the radially inner side is received by the line indicated by the broken line R, and the resin can be prevented from leaking in the axial direction and further to the radially outer side.

[0023] 3B, 3C, and 3D, the range in which the protrusions 53 are formed may not be the entire range of the beam portion 51, but may be at least a part of the range of the beam portion 51. In FIG. 3B, the range in which the protrusions 53 are formed is indicated by hatching. In the example shown in FIG. 3C and FIG. 3D, the protrusions 53 are formed in about half of the radial range of the beam portion 51. In the example shown in FIG. 3C and FIG. 3D, the protrusions 53 are formed on the radial outer side (left side of the paper), but the protrusions 53 may be formed on the radial inner side (right side of the paper).

[0024] Furthermore, in the beam portion 51, the radial range in which the protrusion 53 is formed is not limited to the range of about half the above. That is, the range may be changed as appropriate as long as it is possible to seal against resin leakage in the axial direction and to suppress the load on the wedge 50 when it is crushed by the end cover 40. The radial range of the protrusion 53 may be determined in advance, for example, by experiments. Similarly, the axial height of the protrusion 53 may also be changed as appropriate as long as it is possible to seal against resin leakage in the axial direction and to suppress the load on the wedge 50 when it is crushed by the end cover 40, and the radial height may be determined in advance, for example, by experiments.

[0025] As described above, the protrusions 53 are crushed by the inner surface of the end cover 40 when the rotor core 20 is covered with the end cover 40, but if the diameter of the end cover 40 is smaller than the diameter of the rotor core 20 as shown in Fig. 1, the radial position of the protrusions 53 is located radially inward from the radial end of the end cover 40. This is because if the radial position of the protrusions 53 were radially outward from the radial end of the end cover 40, the protrusions 53 would not be crushed by the end cover 40.

[0026] Next, the effects of this embodiment will be described. As described above, in this embodiment, the wedge 50 is formed with protrusions 53 that protrude from both ends of the rotor core 20 toward the end cover 40 in the axial direction. That is, the length of the wedge 50 in the axial direction of the rotor 1 is longer than the length of the rotor core 20 by the amount of protrusion toward the end cover 40. The protrusions 53 protruding toward the end cover 40 are crushed by the inner surface of the end cover 40 when both ends of the rotor core 20 are covered with the end cover 40. As a result, the protrusions 53 are deformed, the dimensional difference between the wedge 50 and the rotor core 20 is absorbed, and the inner surface of the end cover 40 comes into contact with both ends of the wedge 50 and both ends of the rotor core 20 and is tightly attached. That is, the length of the wedge 50 and the length of the rotor core 20 become the same in the axial direction, and a seal is formed between the end cover 40 and the wedge 50 and the rotor core 20, and no gaps are generated in the axial direction between the end cover 40 and the wedge 50 and the rotor core 20. Note that the length of the wedge 50 and the length of the rotor core 20 being the same here means that they do not necessarily have to be exactly the same length as long as a seal is formed between the end cover 40 and the wedge 50 and between the rotor core 20 and resin is prevented from leaking outward in the radial direction. In other words, as long as a seal is formed between the end cover 40 and the wedge 50 and between the rotor core 20 and the wedge 50, there may be a slight dimensional difference between them.

[0027] By providing such a seal, it is possible to prevent the resin from leaking in the axial direction as described above. By preventing the resin from leaking in the axial direction as described above, it is possible to prevent the resin from leaking outward in the radial direction of rotor core 20.

[0028] In addition, in this embodiment, as described above, by forming the protrusion 53 on the wedge 50 in the axial direction, resin leakage can be sealed, and therefore, there is no need to provide a new part such as a gasket. Therefore, compared to the case where a new part such as a gasket is provided, an increase in the number of parts and the part costs can be avoided (in other words, the number of parts and the part costs can be reduced).

[0029] In addition, the shape of the above-mentioned protrusion 53 is a triangle or semicircle in cross section perpendicular to the circumferential direction. For example, when the shape of the protrusion 53 is a triangle, the contact area with the inner surface of the end cover 40 is smaller than other shapes (e.g., a rectangle or a circle), so that the load on the wedge 50 can be suppressed. That is, when the rotor core 20 is covered with the end cover 40, the inner surface of the end cover 40 comes into contact with the apex of the triangular protrusion 53 in the axial direction. Then, the protrusion 53 is gradually crushed from the apex, and the end cover 40, the wedge 50, and the rotor core 20 are sealed, and the above-mentioned dimensional difference is absorbed. And, since the load on the wedge 50 can be suppressed as described above, it is possible to suppress the occurrence of inconveniences such as the occurrence of cracks in the wedge 50 when the protrusion 53 is crushed by the end cover 40.

[0030] Furthermore, for example, if the shape of protrusion 53 is semicircular, when forming wedge 50 including protrusion 53 using a mold, protrusion 53 has fewer edge portions compared to a triangular or rectangular shape, etc., making it easier to process and suppressing the occurrence of burrs, mold wear, and cracks in wedge 53.

[0031] Moreover, the above-mentioned protrusion 53 is provided so as to cross the surface extending in the circumferential direction of the wedge 50 when viewed from the axial direction. More specifically, the protrusion 53 is formed in the circumferential direction of the beam portion 51, and is set to a predetermined range in the radial direction (about half the range in the radial direction in the examples shown in Figs. 3B, 3C, and 3D). By providing the protrusion 53 in the circumferential range of the beam portion 51 in this way, the protrusion 53 receives the injection pressure of the resin from the radial inside, and the resin leakage in the axial direction can be reliably sealed, and leakage to the radial outside can be prevented. Furthermore, by providing the protrusion 53 in a predetermined range in the radial direction on the beam portion 51 (in other words, by not providing the protrusion 53 uniformly over the entire range in the radial direction), the protrusion 53 can be provided only in a range that can seal the resin leakage in the axial direction, and as a result, the load on the wedge 50 when the protrusion 53 is crushed by the end cover 40 can be reduced compared to the case where the protrusion 53 is provided uniformly over the entire range in the radial direction on the beam portion 51. This reduces the possibility of cracks occurring in the wedge 50.

[0032] In addition, the surface (inner surface) of the end cover 40 that crushes the protrusion 53 is flat. That is, the inner surface of the end cover 40 is flat so as to increase the contact area with the protrusion 53. As a result, compared to when the inner surface of the end cover 40 is a curved surface, for example, the contact area with the protrusion 53 when crushing the protrusion 53 is increased, making it easier to crush the protrusion 53.

[0033] (2) Other embodiments: The above embodiment is an example for carrying out the present invention, and is not limited thereto, and various other embodiments can be adopted. In the above embodiment, the shape of the protrusion 53 is a triangular or semicircular cross section perpendicular to the circumferential direction, but the shape of the protrusion 53 may be any shape that can seal the leakage of resin in the axial direction and further in the radially outer direction. Therefore, for example, the shape of the protrusion 53 may be a rectangular shape such as a trapezoidal shape or a circular shape.

[0034] In the above embodiment, the protrusions 53 of the wedge 50 have the same shape at both ends in the axial direction, but the shapes of the protrusions at one end and the protrusions at the other end of the wedge 50 may be different. For example, the wedge 50 may have a triangular protrusion 53 at one end and a semicircular protrusion 53 at the other end.

[0035] In the above embodiment, the protrusion 53 is a part of the wedge 50 and is therefore integrally molded, but the protrusion 53 may not be integrally molded with the wedge 50 and may be molded separately from the wedge 50. In that case, the protrusion 53 will be attached to the wedge 50 later.

[0036] In the above embodiment, the wedge 50 is formed in a substantially "t" shape when viewed from the axial direction of the rotor 1, but the shape is not limited to a "t" shape as long as it can seal the resin leakage in the axial direction within a predetermined range of the beam portion 51. Other shapes, for example, a "T" shape, may be used. The shape of the wedge 50 is a member that fills the gap between the adjacent salient poles 21, so it may be appropriately changed according to the shape of the rotor core 20 including the salient poles 21. Even in this case, the protrusion 53 may be formed at a position that can seal the resin leakage in the axial direction and, in turn, on the radially outer side.

[0037] Furthermore, the rotor in the above-described embodiment may be manufactured as follows. For example, a manufacturing method for a rotor including a rotor core that rotates about a rotation axis, has a predetermined length in the axial direction, and has a plurality of salient poles adjacent to each other in the circumferential direction and slots formed between the adjacent salient poles, a rotor coil that is wound around the salient poles through the slots, end covers that cover both ends of the rotor core in the axial direction, and wedges that fill gaps between the salient poles around which the rotor coil is wound, the manufacturing method including the steps of injecting resin through holes in the end covers after the rotation axis, the rotor core, the rotor coil, the end covers, and the wedges are assembled in the axial direction, crushing the protrusions with the inner surface of the end covers in the axial direction after the resin is injected, and tightly contacting the end covers with both ends of the wedges and both ends of the rotor core. [Explanation of symbols]

[0038] 1...rotor, 10...rotor shaft, 20...rotor core, 21...salient pole, 22...back yoke, 23...slot, 30...rotor coil, 40...end cover, 50...wedge, 51...beam portion, 52, 52a, 52b...ribs, 53...projection portion.

Claims

1. A rotor that rotates around a rotation axis and has a predetermined length in the axial direction, a rotor core having a plurality of salient poles adjacent to each other in a circumferential direction and a slot formed between the adjacent salient poles; a rotor coil wound around the salient pole through the slot; end covers covering both ends of the rotor core in the axial direction; a wedge that fills a gap between the salient poles around which the rotor coil is wound, The wedge has protrusions that protrude from both ends of the rotor core toward the end covers in the axial direction and are crushed by the end covers, When the protrusion is crushed by the end cover, both ends of the wedge and both ends of the rotor core abut against the end cover in the axial direction. Rotor.

2. The shape of the protrusion is The cross-sectional shape in a direction perpendicular to the circumferential direction is triangular or semicircular. The rotor of claim 1 .

3. The surface of the end cover that crushes the protrusion is a flat surface. A rotor according to claim 1 or 2.

4. The protrusion is provided so as to traverse a surface extending in the circumferential direction of the wedge when viewed in the axial direction. A rotor according to claim 1 or 2.

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