JP2017046545A - Rotary electric machine rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve cooling efficiency for a rotor and a stator through a configuration that has a coolant passage for allowing a rotor core to guide coolant to an outer peripheral end and an axial end in a rotary electric machine rotor.SOLUTION: A rotor core 12 includes a core-side coolant passage 21 that guides coolant, supplied from a shaft-side coolant passage 52 formed in a rotary shaft 50, to the outer peripheral end and axial end of the rotor core, and ejects it to a gap G and to the axial outside. The core-side coolant passage comprises: an axial passage 22 axially extending further on the inner periphery side from a magnet, and opening in the axial end face of the rotor core; an inner-periphery-side passage 24 allowing communication between the shaft-side coolant passage 52 and the axial passage 22; and an outer-periphery-side passage 26 radially extending and allowing communication between the axial passage 22 and the gap G. In the axial passage 22, the smallest cross-section of a portion located on the axial end side of the rotor core 12 from junctions T1, T2 from the outer-periphery-side passage 26 is smaller than the smallest cross-section of the outer-periphery-side passage 26.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a rotor for a rotating electrical machine that includes a rotor core and a magnet embedded in the rotor core and is fixed to a rotating shaft.

  In a magnet-type rotating electrical machine in which magnets are embedded in the rotor core, the temperature of the rotor increases as the rotating electrical machine is driven. As a result, the magnet performance is lowered, the torque and efficiency of the rotating electrical machine are lowered, and the magnet is demagnetized at a high temperature. If a magnet having a high coercive force is employed, the problem of demagnetization can be avoided, but in that case, it is necessary to increase the content of heavy rare earth in the magnet, which causes an increase in cost.

  Therefore, conventionally, a structure for cooling the rotor has been proposed. For example, Patent Document 1 has a configuration in which the rotor is cooled by oil discharged from a supply oil passage formed inside the rotating shaft passing through a plurality of cooling oil passages formed inside the rotor core. It is disclosed. In this configuration, a notch is formed in the d-axis direction where the circumferential position of the magnet coincides with the magnet in each of the plurality of electromagnetic steel sheets that are continuously arranged in the axial direction, and the circumferential position of the notch is shifted by the plurality of electrical steel sheets. The cooling oil passage extending on the d-axis is formed.

  Patent Document 2 discloses a configuration in which a cooling oil passage extends on the q axis between adjacent magnets in a rotor core of a rotating electrical machine. In this configuration, in order to form this cooling oil passage, slits are formed so as to extend at different positions in the radial direction in a plurality of electromagnetic steel sheets continuously arranged in the axial direction, and the slits are communicated with adjacent electromagnetic steel sheets. ing.

JP 2006-067777 A JP 2008-228522 A

  In the configurations described in Patent Documents 1 and 2, a refrigerant path that guides the refrigerant from the inside of the rotor core to the axial end surface is not formed. As a result, there is room for improvement in terms of increasing the cooling efficiency of the rotor. In addition, in order to improve the cooling performance of the rotor, in the configuration in which the refrigerant path that guides the refrigerant to the outer peripheral end and the axial end of the rotor core is simply formed, the refrigerant is in the gap that is the gap between the outer peripheral surface of the rotor core and the stator. It may not be discharged efficiently. Thereby, there is a possibility that the portion facing the gap between the rotor and the stator cannot be efficiently cooled.

  In the configuration described in Patent Document 1, a refrigerant path extending on the d-axis is formed in the rotor core. In this configuration, the main purpose is to cool the magnet with the refrigerant flowing through the cooling oil passage in the rotor core, and the main purpose is not to discharge the refrigerant flowing through the cooling oil passage into the gap. In this configuration, since the intermediate portion of the cooling oil passage is largely blocked by the magnet, the amount of refrigerant flowing through the cooling oil passage is reduced to the gap, and the portion facing the gap in the rotor and the stator cannot be efficiently cooled. there is a possibility.

  The rotor for a rotating electrical machine according to the present invention has a configuration in which the rotor core has a refrigerant path that guides the refrigerant to the outer peripheral end and the axial end, and increases the amount of refrigerant supplied into the gap between the rotor core and the stator to increase the rotor and the stator. The purpose is to increase the cooling efficiency.

  The rotor for a rotating electrical machine of the present invention is a rotor for a rotating electrical machine that includes a rotor core and a magnet embedded in the rotor core and is fixed to a rotating shaft, and the rotor core is formed inside the rotating shaft. A core-side refrigerant path that includes a core-side refrigerant path that guides the refrigerant supplied from the axial-side refrigerant path to an outer peripheral end and an axial end of the rotor core and discharges the refrigerant to a gap between the stator and the axially outer side; Is an axial flow path that extends in the axial direction on the inner peripheral side from the magnet and opens in the axial end surface of the rotor core, and an inner peripheral flow path that connects the axial refrigerant path and the axial flow path. An outer circumferential side channel that extends in a radial direction and communicates the axial channel and the gap. In the axial channel, an axial end of the rotor core from a branch portion with the outer circumferential channel The minimum cross-sectional area of the portion located on the side is Smaller minimum cross-sectional area of the side channels.

  According to the rotor for a rotating electrical machine of the present invention, the rotor core has a refrigerant path that guides the refrigerant to the outer peripheral end and the axial end, and the amount of refrigerant flowing in the outer peripheral flow path can be increased. The cooling efficiency can be increased by increasing the amount of refrigerant supplied into the gap.

It is a figure which shows the upper half part seeing the rotor for rotary electric machines of embodiment which concerns on this invention from one side to the other in the axial direction. FIG. 2 is a view corresponding to the AA cross section of FIG. 1 in the rotating electrical machine including the rotor of FIG. 1. It is a figure which shows the 1st electromagnetic steel plate which comprises the rotor of FIG. It is a figure which shows the 2nd electromagnetic steel plate which comprises the rotor of FIG. It is a figure which shows the 3rd electromagnetic steel plate which comprises the rotor of FIG. It is a figure corresponding to FIG. 2 which shows the comparative example of the rotor for rotary electric machines. It is a figure corresponding to FIG. 2 which shows the other example of the rotor for rotary electric machines of embodiment which concerns on this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The shapes, materials, and numbers described below are illustrative examples, and can be changed as appropriate according to the specifications of the rotating electrical machine. In the following, when a plurality of embodiments and modified examples are included, they can be implemented by appropriately combining them. In the following description, identical elements are denoted by the same reference symbols in all drawings. In the description in the text, the symbols described before are used as necessary.

FIG. 1 is a diagram illustrating an upper half portion of a rotor 10 for a rotating electrical machine according to an embodiment as viewed from one axial direction to the other. FIG. 2 is a view corresponding to the AA cross section of FIG. 1 in the rotating electrical machine 60 including the rotor 10. In FIG. 2, the overall radial length of the rotor 10 is exaggerated, not the same as in FIG. 1, in order to facilitate understanding of the invention. Moreover, in FIG. 2, the thickness of each electromagnetic steel plate 16 is shown larger than actual.

The rotor 10 is used to form the rotating electrical machine 60. For example, the rotating electrical machine 60 is a permanent magnet type synchronous motor that is driven by a three-phase alternating current. For example, the rotating electrical machine 60 is used as a motor that drives a hybrid vehicle, as a generator, or as a motor generator having both functions.

The rotor 10 is a cylindrical member, and the rotary shaft 50 is inserted and fixed inside the rotor 10 during use. The rotor 10 is disposed inside a case (not shown) during use. In a state where the rotor 10 is disposed inside the case, both end portions of the rotary shaft 50 are rotatably supported by the case by bearings (not shown). On the inner side of the case, a cylindrical stator 62 is fixed on the outer side in the radial direction of the rotor 10 as shown in FIG. The stator 62 includes a substantially cylindrical stator core 63 and a stator coil 65 wound around a plurality of teeth 64 protruding from the inner peripheral surface of the stator core 63. A gap G exists between the outer peripheral surface of the rotor 10 and the inner peripheral surface of the stator 62. Thereby, the rotating electrical machine 60 is formed. In the following description, “radial direction” refers to a radial direction that is the radial direction of the rotor 10, and “circumferential direction” refers to a direction along a circle centered on the central axis O of the rotor 10. “Axial direction” refers to a direction along the central axis O of the rotor 10.

  As shown in FIG. 1, the rotor 10 includes a rotor core 12 and magnets 14 that are permanent magnets embedded in a plurality of positions in the circumferential direction of the rotor core 12. The rotor core 12 is a laminate formed by laminating a plurality of electromagnetic steel plates 16 that are magnetic materials. A shaft hole 18 is formed at the center of the rotor core 12, and a plurality of magnet holes 20 are formed around the shaft hole 18. The magnet hole 20 has a substantially rectangular shape when viewed from one side in the axial direction. The plurality of magnet holes 20 are arranged at intervals along the circumferential direction of the rotor core 12.

  The electromagnetic steel plate 16 has a disk shape, for example, a silicon electromagnetic steel plate. The electromagnetic steel plate 16 is formed by, for example, punching a thin steel plate having a thickness of 0.5 mm or less in an annular shape. In the electromagnetic steel sheet 16, the central shaft hole and a plurality of magnet holes 20 a (FIG. 3A, FIG. 3 b, and FIG. 3 c) around the center hole are formed by punching.

The shaft holes 18 of the rotor core 12 are formed by connecting the shaft holes of the plurality of electromagnetic steel plates 16 in the axial direction. A plurality of magnet holes 20 of the rotor core 12 are formed by connecting the plurality of magnet holes 20a of the plurality of electromagnetic steel plates 16 in the axial direction. A magnet 14 is inserted into each magnet hole 20.

  The magnet 14 has a rectangular parallelepiped shape elongated in the axial direction, and the magnetization direction thereof is a direction orthogonal to the outer peripheral side surface and the inner peripheral side surface. The magnet 14 is fixed in the magnet hole 20 by charging the resin in the magnet hole 20. Two adjacent magnets 14 form one magnetic pole 15. The two magnets 14 forming one magnetic pole 15 are arranged so as to expand in a substantially V shape toward the outer peripheral side of the rotor core 12. One magnetic pole may be formed by three or more magnets.

  A refrigerant path through which a refrigerant passes in order to cool the rotor 10 and the stator 62 is formed in the rotating shaft 50 and the rotor core 12. The refrigerant path is broadly classified into a shaft side refrigerant path 52 formed in the rotating shaft 50 and a core side refrigerant path 21 formed in the rotor core 12. The shaft-side refrigerant path 52 is a hole that passes through the axis of the rotating shaft 50. As shown in FIG. 2, the shaft-side refrigerant path 52 includes an axial flow path 53 that extends from one end (left end in FIG. 2) of the rotating shaft 50 to the substantially axial center, and an axial direction that is positioned approximately at the center of the rotating shaft 50. And a radial flow path 54 extending from one end of the flow path 53 in the radial direction to reach the outer peripheral end of the rotation shaft 50.

  The core-side refrigerant path 21 guides the refrigerant supplied from the shaft-side refrigerant path 52 to the outer peripheral end of the rotor core 12 and both ends in the axial direction of the rotor core 12, so that the gap G between the rotor core 12 and specifically the stator 62. And a refrigerant path that discharges outward in the axial direction. The refrigerant is a liquid such as cooling oil, for example. The refrigerant is supplied to the shaft-side refrigerant path 52 from a refrigerant supply source (not shown) that is provided outside the rotating electrical machine 60 and includes a pump and the like. A part of the refrigerant supplied to the shaft-side refrigerant path 52 is discharged from the outer peripheral end of the rotor core 12 to the gap G through the core-side refrigerant path 21. The refrigerant released into the gap G travels through the gap G and then falls to the bottom of the case of the rotating electrical machine 60.

In addition, the refrigerant that is not released into the gap G is released from both ends of the rotor core 12 in the axial direction and falls to the bottom of the case. The refrigerant falling to the bottom of the case is recovered and cooled at the bottom of the case or at another part, and then returned to the refrigerant supply source.

  The core-side refrigerant path 21 is roughly divided into an axial flow path 22, an inner peripheral flow path 24, and an outer peripheral flow path 26. The axial flow path 22 is a refrigerant path extending in the axial direction of the rotor core 12 and penetrating therethrough. As shown in FIG. 1, the axial direction flow path 22 is provided on the q axis of the rotating electrical machine 60 (FIG. 2) at a position on the inner peripheral side from the magnet 14. The q axis is an axis that passes through the circumferential center position between two adjacent magnetic poles 15 and the center of the rotor 10. The d-axis is an axis passing through the circumferential center position of one magnetic pole 15 and the center of the rotor 10. In the embodiment, the axial flow path 22 is provided on each q-axis.

  The axial flow path 22 is open to both axial end surfaces of the rotor core 12, and the refrigerant is discharged from the openings. As shown in FIG. 2, the cross-sectional area in a plane orthogonal to the axial direction of the axial flow path 22 is the largest in one electromagnetic steel plate 16 located in the center of the rotor core 12, and the electromagnetic steel plates on both sides thereof. 16 are the same size and smaller than the central cross-sectional area.

  The inner peripheral flow path 24 is a refrigerant path that connects the axial refrigerant path 52 and the axial flow path 22. The inner peripheral flow path 24 is provided at the approximate center in the axial direction of the rotor core 12. Each inner peripheral flow path 24 includes a first flow path 24 a extending in the radial direction from the inner peripheral end of the rotor core 12, and a second flow path 24 b communicating the first flow path 24 a and the axial flow path 22. . As shown in FIG. 1, the first flow path 24 a is a flow path extending on each d-axis, and one end of the first flow path 24 a is connected to the shaft-side refrigerant path 52 and the other end is disposed on the inner peripheral side of the magnet 14. The The other end of the first flow path 24a extends in a substantially elliptical shape to facilitate communication with the second flow path 24b. The cross-sectional shape about the plane orthogonal to the longitudinal direction of the first flow path 24a and the second flow path 24b is a rectangle.

  The second flow path 24 b is provided at a position on the inner peripheral side with respect to the magnet 14. One end of the second flow path 24b is at a position overlapping the other end of the first flow path 24a. Then, as shown in FIG. 2, the electromagnetic steel plate 16 in which the second flow path 24b is formed is laminated adjacent to the electromagnetic steel plate 16 in which the first flow path 24a is formed, so that the second flow path 24b and The first flow path 24a communicates with the first flow path 24a.

  As shown in FIG. 1, the other end of the second flow path 24 b is connected to the axial flow path 22. Moreover, as shown in FIG. 2, the 2nd flow path 24b is connected to the axial direction both sides of the other end of the 1st flow path 24a of an axial center. Further, at a position adjacent to one axial direction side (left side in FIG. 2) of the first flow path 24a, as shown in FIG. 1, the other end of one first flow path 24a is opposite to the circumferential direction. Two second flow paths 24b extending in an inclined manner are connected. Even at a position adjacent to the other axial side of the first flow path 24a (the right side in FIG. 2), two second flow paths 24b are connected to the other end of the first flow path 24a in the same manner as the one side in the axial direction. The Accordingly, a total of four second flow paths 24b are connected to one first flow path 24a on both axial sides.

  The outer peripheral flow path 26 is a refrigerant path that extends radially outward from the axial center of the axial flow path 22 and connects the axial flow path 22 and the gap G. One end of the outer circumferential channel 26 is connected to the axial channel, and the other end of the outer circumferential channel 26 opens to the outer circumferential surface of the rotor core 12. Then, the refrigerant is discharged from the other end opening of the outer peripheral flow path 26. The outer peripheral flow path 26 is provided only at one axial position, which is the axial center position of the rotor core 12. Moreover, the outer peripheral side flow path 26 is provided on each q-axis.

In the axial flow path 22, the minimum cross-sectional area S1 of the portion located on the axial end side of the rotor core 12 from the branch portions T1 and T2 (FIG. 2) with the outer peripheral flow path 26 is It is smaller than the minimum cross-sectional area S2 (S1 <S2). Specifically, the cross-sectional shape of the axial direction flow path 22 in the longitudinal direction, that is, the plane orthogonal to the axial direction is circular. Moreover, the cross-sectional shape about the plane direction orthogonal to the longitudinal direction of the outer peripheral side flow path 26, ie, the radial direction of the rotor 10, is a rectangle. In addition, when the diameter of the portion connected to the axial direction end side of the second flow path 24b in the axial flow path 22 is d1, and the axial width of the outer peripheral flow path 26 is d2, the diameter d1 is It is smaller than the axial width d2 (d1 <d2). The cross-sectional area of the outer peripheral flow path 26 is the same in the overall length in the radial direction of the outer peripheral flow path 26. Therefore, in the core side refrigerant path 21, more refrigerant flows in the outer peripheral side flow path 26 than in the axial direction flow path 22. As a result, as will be described later, the amount of refrigerant supplied into the gap G can be increased to increase the cooling efficiency.

  The core-side refrigerant path 21 is formed by appropriately forming holes, slots, or communication paths in the electromagnetic steel sheet 16 that forms the rotor core 12. The shape of the electromagnetic steel sheet 16 that forms the rotor core 12 varies depending on the axial position of the rotor core 12. This will be described with reference to FIGS. 3A to 3C.

  There are roughly three types of electromagnetic steel sheets 16 that form the rotor core 12. Specifically, the rotor core 12 is formed by laminating the electromagnetic steel plate 16 shown in FIG. 3A, the electromagnetic steel plate 16 shown in FIG. 3B, and the electromagnetic steel plate 16 shown in FIG. 3C. Hereinafter, the electromagnetic steel plate 16 illustrated in FIG. 3A is referred to as a first electromagnetic steel plate 16a, the electromagnetic steel plate 16 illustrated in FIG. 3B is referred to as a second electromagnetic steel plate 16b, and the electromagnetic steel plate 16 illustrated in FIG. 3C may be referred to as a third electromagnetic steel plate 16c. is there.

A plurality of magnet holes 20a and first holes 22a are formed in the first electromagnetic steel plate 16a shown in FIG. 3A. The first electromagnetic steel plate 16a is disposed in most of the rotor core 12 except for the vicinity of the center in the axial direction. The first hole 22a is a through hole arranged on the inner circumference side of the magnet hole 20a and on the q axis, and forms the axial flow path 22 (FIGS. 1 and 2). The 1st hole 22a formed in the 1st electromagnetic steel plate 16a is smaller than the below-mentioned 2nd hole 22b (FIG. 3B, FIG. 3C) formed in the 2nd electromagnetic steel plate 16b and the 3rd electromagnetic steel plate 16c. The outer peripheral edge of the first hole 22a is close to the outer peripheral side of the second hole 22b.

  A plurality of magnet holes 20a, a second hole 22b, an inner peripheral slot 28, and an outer peripheral slot 30 are formed in the second electromagnetic steel plate 16b shown in FIG. 3B. The second electromagnetic steel plate 16 b is disposed at the center in the axial direction of the rotor core 12. The inner circumferential slot 28 is a slot extending radially outward from the inner circumferential end along the d axis, and constitutes the first flow path 24a (FIGS. 1 and 2). The outer peripheral slot 30 is a slot extending radially inward from the outer peripheral end along the q axis, and constitutes the outer peripheral flow path 26 (FIGS. 1 and 2). The second hole 22 b is connected to the outer peripheral side slot 30.

  A plurality of magnet holes 20a, second holes 22b, and intermediate slots 32 are formed in the third electromagnetic steel plate 16c shown in FIG. 3C. The 3rd electromagnetic steel plate 16c is arrange | positioned at the axial direction both sides of the 2nd electromagnetic steel plate 16b of FIG. 3B. The intermediate slot 32 is a slot extending in a direction inclined with respect to the circumferential direction at a position on the inner circumferential side from the magnet hole 20, and constitutes the second flow path 24b (FIGS. 1 and 2). The second hole 22b of the third electromagnetic steel plate 16c is connected to the intermediate slot 32.

  The rotor core 12 having the core-side refrigerant path 21 (FIGS. 1 and 2) is formed by stacking such a plurality of types of electromagnetic steel plates 16a, 16b, and 16c.

  Furthermore, in the embodiment, in the axial flow path 22, the minimum cross-sectional area S1 of the portion located on the axial direction end side of the rotor core 12 from the branch portions T1 and T2 (FIG. 2) with the outer peripheral flow path 26 is It is smaller than the minimum cross-sectional area S2 of the flow path 26 (S1 <S2). Thereby, since the rotor core 12 has the core-side refrigerant path 21 that guides the refrigerant to the outer peripheral end and the axial end, the amount of refrigerant flowing through the outer peripheral flow path 26 can be increased, so the amount of refrigerant supplied into the gap G can be reduced. Increase the cooling efficiency. For example, the refrigerant supplied from the shaft-side refrigerant path 52 to the core-side refrigerant path 21 as shown by a solid line arrow α in FIG. 2 receives a radially outward force due to the centrifugal force when the rotor 10 rotates. In addition, the cross-sectional area of the outer peripheral flow path 26 is larger than the cross-sectional area of the axial flow path 22. As a result, most of the refrigerant in the core-side refrigerant path 21 passes through the axial flow path 22 and the outer peripheral flow path 26 from the inner peripheral flow path 24 through the gap G as shown by the solid arrow β in FIG. Proceed to Since the refrigerant having advanced to the gap G efficiently cools the outer peripheral side end of the rotor core 12 and the inner peripheral side end of the stator 62, the cooling efficiency of the rotor 10 and the stator 62 can be increased. For example, since the temperature rise at the outer peripheral end of the rotor core 12 has a large effect on the loss of the entire rotor, the loss can be efficiently reduced by cooling the outer peripheral end. Further, the stator coil 65 can be efficiently cooled by supplying the coolant to the inner peripheral side end of the stator 62.

  Further, the refrigerant is also discharged from both axial ends of the axial flow path 22 as indicated by broken line arrows γ in FIG. Thereby, this refrigerant cools the inside of the rotor core 12 and both axial ends. At this time, the rotor 10 can be efficiently cooled by increasing the flow rate of the refrigerant.

  Further, the refrigerant is discharged from the outer peripheral side flow path 26 to the gap G. The outer peripheral flow path 26 is provided only at the center in the axial direction of the rotor core 12. Thereby, on the outer peripheral surface of the rotor core 12, the refrigerant discharge port exists only in the center in the axial direction. Therefore, the refrigerant discharged from the center in the axial direction does not interfere with the refrigerant discharged from another discharge port on the outer peripheral surface of the rotor core 12 in the process of proceeding to both ends of the gap G in the axial direction. It is released quickly. As a result, drag loss due to refrigerant stagnation can be effectively prevented.

  In addition, the refrigerant flows through both the axial flow path 22 located on the inner circumferential side from the magnet 14 and the gap G located on the outer circumferential side from the magnet 14. Thereby, the magnet 14 is cooled from both the inner peripheral side and the outer peripheral side, and the magnet 14 can be cooled more effectively. For this reason, the performance degradation and demagnetization of the magnet 14 due to heat can be prevented. Since the magnet 14 can be effectively cooled in this way, the amount of heavy rare earth used in the magnet 14 can be reduced. For this reason, cost reduction can be achieved. Moreover, since the rotor 10 can be efficiently cooled as described above, the operating range of the rotating electrical machine 60 can be expanded and the rotating electrical machine 60 can be downsized.

  Furthermore, in the embodiment, the core-side refrigerant path 21 is disposed so as not to divide the d-axis magnetic path Ld and the q-axis magnetic path Lq. Thereby, since both the magnet torque and reluctance torque of the rotary electric machine 60 can be used effectively, the output performance of the rotary electric machine 60 can be prevented from deteriorating.

  Specifically, as indicated by the dashed arrows in FIGS. 3A to 3C, the d-axis magnetic path Ld passes through the circumferential center of the two magnet holes 20a forming one magnetic pole 15 (FIG. 1). Proceed into the rotor core 12. Then, the d-axis magnetic path Ld crosses the q-axis and goes out of the rotor core 12 through the circumferential center of two magnet holes 20a forming another adjacent magnetic pole 15.

On the other hand, as indicated by the two-dot chain line arrows in FIGS. 3A to 3C, the q-axis magnetic path Lq advances from between the adjacent magnetic poles 15 into the rotor core 12, and then crosses the d-axis magnetic path Ld to be adjacent. It goes out of the rotor core 12 so as to pass between the other magnetic poles 15 that fit. If a hole or groove such as a slot exists in the middle of the path of the d-axis magnetic path Ld and the q-axis magnetic path Lq, the magnet torque and the reluctance torque are reduced.

  In the embodiment, the intermediate slot 32 of the second flow path 24b extending in the oblique direction is formed in the third electromagnetic steel plate 16c so as not to greatly disturb the d-axis magnetic path Ld. Moreover, the outer peripheral side flow path 26 extended on a q-axis is formed in the 2nd electromagnetic steel plate 16b different from the 3rd electromagnetic steel plate 16c. Further, the inner peripheral side slot 28 of the first flow path 24a extends only to the middle in the radial direction of the second electromagnetic steel plate 16b. Thereby, the d-axis magnetic path Ld is not divided by the core-side refrigerant path 21, and the magnetic resistance of the d-axis magnetic path Ld can be kept low.

Moreover, in the embodiment, the outer peripheral flow path 26 extending on the q axis extends only to the inner peripheral position relative to the magnet 14 of the second electromagnetic steel plate 16b so that the q axis magnetic path Lq is not significantly inhibited. Not. Moreover, the inner peripheral side slot 28 of the 1st flow path 24a is extended only to the radial direction half of the 2nd electromagnetic steel plate 16b. As a result, the q-axis magnetic path Lq is not divided by the core-side refrigerant path 21, and the magnetic resistance can be kept low.

  FIG. 4 is a diagram corresponding to FIG. 2 showing a comparative example of the rotor. In the comparative example, in the embodiment shown in FIGS. 1 to 3C, in the axial flow path 22, the minimum breakage of the portion located on the axial end side of the rotor core 12 from the branch portions T <b> 1 and T <b> 2 with the outer circumferential flow path 26. The area S1 is larger than the minimum cross-sectional area S2 of the outer peripheral channel 26 (S1> S2). In addition, when the diameter of the portion connected to the axial direction end side of the second flow path 24b in the axial flow path 22 is d3 and the axial width of the outer peripheral flow path 26 is d2, the diameter d3 is It is larger than the axial width d2 (d3> d2).

In such a comparative example, among the refrigerant flowing through the core-side refrigerant path 21, the amount of refrigerant flowing through the axial flow path 22 is greater than in the embodiment shown in FIGS. 1 to 3C. As a result, the amount of refrigerant flowing through the outer peripheral flow path 26 is reduced, so that the amount of refrigerant supplied into the gap G may be reduced and the cooling efficiency of the rotor 10 and the stator 62 may deteriorate. According to the above embodiment, such inconvenience can be prevented.

  FIG. 5 is a view corresponding to FIG. 2 illustrating another example of the rotor 10 according to the embodiment. In another example of FIG. 5, in the embodiment shown in FIGS. 1 to 3C, one electromagnetic steel plate 16 disposed adjacent to the outside in the axial direction of the two electromagnetic steel plates 16 having the inner circumferential flow path 24. The diameter d1 of the first hole 22a is made smaller than the axial width d2 of the outer peripheral flow path 26. The cross-sectional area of the first hole 22a having the diameter d1 is smaller than the cross-sectional area of the outer peripheral flow path 26. Thereby, only a part of the cross-sectional area of the axial flow path 22 is smaller than the cross-sectional area of the outer peripheral flow path 26. On the other hand, the cross-sectional area of the remaining portion of the axial flow path 22 is larger than the cross-sectional area of the outer peripheral flow path 26.

Even in the configuration of this other example, as in the embodiment shown in FIGS. 1 to 3C, the axial flow path 22 is positioned on the axial end side of the rotor core 12 from the branch portions T <b> 1 and T <b> 2 with the outer peripheral flow path 26. The minimum cross-sectional area S1 of the portion to be smaller is smaller than the minimum cross-sectional area S2 of the outer peripheral flow path 26 (S1 <S2). As a result, the amount of refrigerant flowing through the outer peripheral side flow path 26 can be increased, so that the cooling efficiency of the rotor 10 and the stator 62 can be increased by increasing the amount of refrigerant supplied into the gap G. Other configurations and operations are the same as those of the embodiment shown in FIGS. 1 to 3C. In the configuration of FIG. 5, the number of the electromagnetic steel plates 16 that reduce the cross-sectional area of the axial flow path 22 is not limited to one on both sides in the axial direction, but may be an arbitrary number of two or more.

  In the embodiments of the above examples, the first flow path 24a, the second flow path 24b, and the outer peripheral flow path 26 are configured by slots that penetrate the electromagnetic steel sheet 16, but instead of the slots, penetrate the electromagnetic steel sheet 16. The channels 24a, 24b, and 26 may be configured by the grooves that are not. In addition, the first flow path 24 a, the second flow path 24 b, and the outer peripheral flow path 26 may be configured by a portion where a plurality of electromagnetic steel sheets 16 are laminated instead of the single electromagnetic steel sheet 16. Further, in the embodiment, the case where the rotor core 12 is made of a laminated steel plate in which the electromagnetic steel plates 16 are laminated has been described. However, if the strength characteristics and the magnetic characteristics can be maintained, the rotor core 12 is made of other than the laminated steel plates, for example, a pressure You may comprise from a powder magnetic core.

  Furthermore, in the embodiment, the first flow path 24a and the inner circumferential slot 28 are arranged on the d-axis, but the first flow path 24a and the inner circumferential slot 28 are shifted in the circumferential direction with respect to the q-axis. As long as it is formed at a position, it may be provided not only on the d-axis but also at another position. Further, the axial flow path 22 may be formed at every two magnetic poles 15 in the rotor core 12. At this time, the number of the first flow paths 24a, the second flow paths 24b, and the outer peripheral flow paths 26 connected to the axial flow path 22 can be appropriately changed.

  DESCRIPTION OF SYMBOLS 10 Rotating machine rotor (rotor), 12 Rotor core, 14 Magnet, 15 Magnetic pole 16 Electrical steel plate, 16a 1st electrical steel plate, 16b 2nd electrical steel plate, 16c 3rd electrical steel plate, 18 shaft hole, 20, 20a Magnet hole, 21 Core side refrigerant path, 22 axial direction flow path, 22a 1st hole, 22b 2nd hole, 24 inner circumference side flow path, 24a first flow path, 24b second flow path, 26 outer circumference side flow path, 28 inner circumference side Slot, 30 Outer peripheral side slot, 32 Intermediate slot, 50 Rotating shaft, 52 Axial side refrigerant passage, 53 Axial flow passage, 54 Radial flow passage, 60 Rotating electrical machine, 62 Stator, 63 Stator core, 64 teeth, 65 Stator coil.

Claims (1)

A rotor for a rotating electrical machine comprising a rotor core and a magnet embedded in the rotor core and fixed to a rotating shaft,
The rotor core is led to the refrigerant supplied from the shaft side refrigerant passage formed in the interior of the rotary shaft and the outer peripheral edge and an axial end of the rotor core, released into the gap and axially outer between the stator Including a core side refrigerant path to
The core-side refrigerant path is
An axial flow path extending in the axial direction on the inner peripheral side from the magnet and opening in the axial end surface of the rotor core;
An inner circumferential flow path that communicates the axial refrigerant path and the axial flow path;
An outer circumferential channel that extends in the radial direction and communicates the axial channel and the gap;
A rotor for a rotating electrical machine, wherein a minimum cross-sectional area of a portion located in an axial direction end side of the rotor core is smaller than a minimum cross-sectional area of the outer peripheral side flow path in the axial flow path. .

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