Electric motor

Abstract

To disclose one example of a rotor for a reluctance motor in which occurrence of a large load on a bearing supporting a rotor shaft when the rotation speed of the rotor increases is considered.SOLUTION: An electric motor includes an oil supply unit that supplies an oil to a gap Ag between an inner circumferential surface 3G of a stator 3 and an outer circumferential surface 5F of a rotor 5. Accordingly, the rotor 5 and the stator 3 have the same relationship as a relationship of a shaft and a plane bearing. That is, the rotor 5 functions as the shaft, and the inner circumferential surface of the stator 3 functions as the plane bearing. Therefore, even in a case where the rotor 5 rotates at high speed, the oil that exists in the gap Ag can receive a centrifugal force acting on the rotor 5 due to eccentricity so that the rotor 5 can be stably rotated at high speed.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present disclosure relates to electric motors. [Background technology]

[0002] The rotor shaft of the electric motor is usually rotatably supported by a bearing such as a rolling bearing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4949983 Summary of the Invention [Problem to be solved by the invention]

[0004] As the rotational speed of the rotor increases, a large load is placed on the bearings that support the rotor shaft. The present disclosure discloses an example of a rotor for a reluctance motor in consideration of this point. [Means for solving the problem]

[0005] The electric motor preferably includes, for example, a stator (3), a rotor (5) that rotates within the stator (3), and an oil supply section (3E, 7D) that supplies oil to a gap (Ag) between an inner peripheral surface (3G) of the stator (3) and an outer peripheral surface (5F) of the rotor (5).

[0006] This creates a relationship between the rotor 5 and the stator 3 similar to that between a shaft and a plain bearing (slide bearing). In other words, the rotor 5 corresponds to the shaft, and the inner peripheral surface of the stator 3 functions as a plain bearing (also called a metal).

[0007] Therefore, even when the rotor (5) rotates at high speed, the centrifugal force acting on the rotor (5) due to eccentricity can be received by the oil present in the gap (Ag), so that the rotor (5) can be rotated stably at high speed.

[0008] Incidentally, the symbols in each of the parentheses above are examples showing the correspondence with the specific configurations, etc. described in the embodiments described below, and the present disclosure is not limited to the specific configurations, etc. shown by the symbols in the parentheses above. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram showing a reluctance motor according to a first embodiment; [Figure 2] FIG. 2 is a diagram showing a rotor according to the first embodiment. [Figure 3] FIG. 2 is a diagram showing a reluctance section according to the first embodiment. [Figure 4] FIG. 2 is a diagram showing a reluctance section according to the first embodiment. [Figure 5] FIG. 2 is a cross-sectional view of an electromagnetic steel sheet of the rotor core according to the first embodiment. [Figure 6] FIG. 2 is a view showing an end plate according to the first embodiment. [Figure 7] FIG. 2 is a view showing an end plate according to the first embodiment. [Figure 8] FIG. 2 is a diagram showing a stator according to the first embodiment. [Figure 9] FIG. 2 is a diagram showing an oil supply path of the motor according to the first embodiment. [Figure 10] FIG. 2 is a diagram showing a magnetic gap according to the first embodiment. [Figure 11] FIG. 2 is a diagram showing a stator according to the first embodiment. [Figure 12] FIG. 2 is a cross-sectional view of an electromagnetic steel sheet of the stator core according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] The following "embodiments of the invention" are examples of embodiments that fall within the technical scope of the present disclosure. In other words, the invention-specific matters described in the claims are not limited to the specific configurations and structures shown in the following embodiments.

[0011] Note that arrows and diagonal lines indicating directions in each figure are provided to facilitate understanding of the relationship between the figures and the shapes of each component or part. Therefore, the invention disclosed in this disclosure is not limited to the directions indicated in each figure. Diagonal lines do not necessarily indicate cross-sectional views.

[0012] At least one component or part that is described with a reference symbol is provided unless otherwise specified, such as "one." In other words, unless otherwise specified, such as "one," two or more components may be provided.

[0013] The rotor for a reluctance motor (hereinafter referred to as the rotor) and the reluctance motor using the rotor disclosed in this disclosure include at least the components such as the members or parts that are labeled and described, as well as the structural parts shown in the drawings.

[0014] (First embodiment) <1. Overview of reluctance motors> 1, a reluctance motor (hereinafter referred to as motor) 1 is an electric motor including at least a stator 3, a rotor 5, and a housing (not shown), etc. The stator 3 induces a rotating magnetic field around the rotor 5.

[0015] The rotor 5 rotates within the stator 3 in synchronization with the rotating magnetic field, mainly by utilizing the attractive force generated between the stator 3 and the rotor 5. The housing is a casing that houses the stator 3. The motor 1 according to this embodiment is applied to an electric motor for driving electric vehicles and hybrid vehicles.

[0016] <2. Rotor> 2.1 Rotor configuration 2, the rotor 5 includes at least a rotor core 5A, end plates 5B and 5C, and a shaft 5D. The rotor core 5A is formed by laminating a number of electromagnetic steel plates 5E in a direction parallel to the central axis of rotation Lo (hereinafter also referred to as the axial direction).

[0017] End plate 5B is a disk-shaped member arranged at one axial end (the right end in FIG. 2) of rotor core 5A, and end plate 5C is a disk-shaped member arranged at the other axial end (the left end in FIG. 2) of rotor core 5A.

[0018] The shaft 5D axially passes through the rotor core 5A and the end plates 5B, 5C and supports the rotor core 5A and the end plates 5B, 5C. One and the other axial ends of the shaft 5D are rotatably supported by the housing via bearings (not shown).

[0019] As shown in Fig. 3, rotor core 5A is provided with at least one type (multiple types in this embodiment) of reluctance sections 7 and 8. Reluctance sections 7 and 8 are portions that function as magnetic resistance against the rotating magnetic field induced by stator 3. The reluctance sections 7 and 8 are areas shaded with dashed double-dashed lines in Fig. 3.

[0020] Therefore, as shown in Fig. 4, the magnetic field lines incident on the rotor 5 from the stator 3 are generated along the reluctance sections 7 and 8 and return to the stator 3. In other words, the reluctance sections 7 and 8 function to separate the magnetic path of the magnetic flux induced in the rotor 5 by the rotating magnetic field from the rest of the rotor 5.

[0021] In the rotor core 5A according to this embodiment, the multiple reluctance sections 7, 8 are configured to have a substantially arc-like shape, as shown in Fig. 3. In other words, the reluctance sections 7, 8 projected onto an imaginary plane perpendicular to the axial direction extend in a curved line that is convex toward the central axis of rotation.

[0022] The reluctance sections 7 and 8 are arranged in series in the diameter direction of the rotor core 5A. That is, the reluctance section 7 is located closer to the outer peripheral surface of the rotor core 5A than the reluctance section 8.

[0023] 1, rotor core 5A is provided with a plurality of reluctance sections 7 and 8. These reluctance sections 7 and 8 are arranged side by side in the rotation direction of rotor 5 (hereinafter referred to as the circumferential direction).

[0024] Incidentally, it is desirable that each of the reluctance portions 7 and 8 has a large magnetic resistance, and therefore a typical reluctance portion is configured to generate a larger magnetic resistance than the electromagnetic steel plate 5E.

[0025] For this reason, one or more holes 7A, 8A are provided in each of the reluctance sections 7, 8 according to this embodiment. At least each of the holes 7A is a through-hole that passes through the rotor core 5A in the axial direction, as shown in Fig. 2. In this embodiment, each of the holes 8A also passes through the rotor core 5A in the axial direction.

[0026] That is, one axial end of each of the holes 7A and 8A reaches the end plate 5B, and the other axial end of each of the holes 7A and 8A reaches the end plate 5C. At least a portion of each of the reluctance portions 7 (each of the holes 7A in this embodiment) also serves as a coolant passage through which a coolant for cooling the rotor core 5A flows.

[0027] The holes 7A (hereinafter referred to as coolant passages 7A) are filled with coolant (oil in this embodiment). Oil has a lower magnetic permeability than the magnetic steel sheets 5E. Therefore, the coolant passages 7A function as reluctance parts that generate a larger magnetic resistance than the magnetic steel sheets 5E.

[0028] As shown in FIG. 3, a permanent magnet M is disposed in the hole 8A of each reluctance portion 8. The magnetization direction of the permanent magnet M is configured to be approximately perpendicular to the magnetic field lines induced in the magnetic path. Therefore, the permanent magnet M functions as a magnetic resistance against the magnetic field induced in the rotor 5. The type of each permanent magnet M and the embedding method are not important.

[0029] Incidentally, holes 7A and 8A are provided in the reluctance sections 7 and 8, and each hole (coolant passage) 7A is filled with coolant, and each hole 8A has a permanent magnet M disposed therein. For this reason, there is a risk that the rotor 5 will be significantly deformed from each of the holes 7A and 8A due to the centrifugal force generated when the rotor 5 rotates.

[0030] For this reason, at least one bridge portion 7B, 7C, 8B, 8C is provided in a part of each of the reluctance portions 7, 8. Each of the bridge portions 7B, 7C, 8B, 8C is a portion for ensuring strength against centrifugal force.

[0031] Specifically, each bridge portion 7B, 7C sandwiches the reluctance portion 7 between two portions on one side perpendicular to the extension direction of the reluctance portion 7. Similarly, each bridge portion 8B, 8C sandwiches the reluctance portion 8 between two portions on one side perpendicular to the extension direction of the reluctance portion 8.

[0032] That is, the reluctance section 7 according to this embodiment is a substantially arc-shaped section made up of multiple holes 7A and bridge sections 7B and 7C. Similarly, the reluctance section 8 according to this embodiment is a substantially arc-shaped section made up of multiple permanent magnets M and bridge sections 8B and 8C.

[0033] <2.2. Details of the bridge section> The bridge portions 7B, 7C, 8B, and 8C have roughly the same configuration. Therefore, the following describes the bridges according to this embodiment in detail, taking as an example the bridge portion 7C of the reluctance portion 7. The bridge portion 7C is located on the end side of the reluctance portion 7, which extends in a substantially arc shape, on the outer peripheral surface 5F of the rotor core 5A.

[0034] A bridge portion 7C is provided on each electromagnetic steel sheet 5E. As shown in Fig. 5, the bridge portion 7C is configured by a recess 7D that is recessed in part of the electromagnetic steel sheet 5E in the thickness direction of the electromagnetic steel sheet 5E. A modified portion 7E is provided at the bottom of the recess 7D.

[0035] The modified portion 7E is a portion having a lower magnetic permeability than the other portion 7F. Note that the modified portion 7E according to this embodiment is a portion in which the electromagnetic steel sheet 5E is melted and modified together with the modifying metal or modifying alloy by laser light.

[0036] The recesses 7D are formed by applying press working to a predetermined area W including the modified portions 7E after the electromagnetic steel sheet 5E has been modified. The dimension T1 is the thickness of the recesses 7D after the press working. The dimension T2 is the original thickness of the electromagnetic steel sheet 5E.

[0037] 3, each recess 7D of the bridge portion 7C is a groove-shaped recess extending from the outer peripheral surface 5F of the rotor core 5A to the hole 7A adjacent to the outer peripheral surface 5F. Therefore, the recess 7D functions as an oil passage that connects the coolant passage 7A and the outer peripheral surface of the rotor core 5A.

[0038] 2.3 Supplying oil to the rotor 2, oil is injected into the rotor 5 from the shaft 5D and flows into the coolant passage 7A via the passage 5G. The passage 5G is formed between the rotor core 5A and the end plate 5B and extends from the passage side provided inside the shaft 5D to the outer peripheral surface 5F.

[0039] For this reason, at least one groove 5H (see FIG. 6) that forms a passage 5G is provided in the portion of the end plate 5B that faces the rotor core 5A. The groove 5H extends radially from the shaft 5D to the outer circumferential surface 5F.

[0040] A portion of the oil that has flowed into the coolant passage 7A flows out from the recess 7D onto the outer peripheral surface 5F due to centrifugal force acting on the oil. The remaining oil reaches the end plate 5C. The oil that has reached the end plate 5C flows out from the outlet 5J onto the outer peripheral surface 5F.

[0041] For this reason, a plurality of concave grooves 5K that form each outlet 5J are provided in the end plate 5C in a portion corresponding to the coolant passage 7A, as shown in Fig. 7. Each groove 5K faces only a portion of the outer circumferential surface 5F side of the hole 7A.

[0042] 3. Stator configuration As shown in Fig. 1, the stator 3 is configured to include a stator core 3A and windings 3B. As shown in Fig. 8, the stator core 3A is configured by stacking a number of electromagnetic steel plates 3C in the axial direction.

[0043] The stator core 3A has a plurality of slots 3D in which windings 3B are housed. The windings 3B are coil wires that induce a rotating magnetic field when current is periodically applied. Cooling oil flows through each slot 3D, as shown in FIG.

[0044] In this embodiment, the cooling oil supplied to the rotor core 5A is the same as the cooling oil supplied to the stator core 3A. In other words, the oil pumped from the pump P is divided into oil to be injected into the shaft 5D and oil to be injected into the stator core 3A.

[0045] The oil discharged from the rotor core 5A and the stator core 3A is collected in an oil pan Op or the like and then cooled in an oil cooler Ex. The cooled oil is sucked into the pump P and injected again into the shaft 5D and the stator core 3A.

[0046] <3.1 Structure around the slot> 10, at least one of the slots 3D (in this embodiment, all of the slots 3D) is provided with a communication passage 3E. The communication passage 3E is a passage that connects the slot 3D with the magnetic gap Ag. The magnetic gap Ag refers to the gap between the inner circumferential surface 3G of the stator 3 and the outer circumferential surface 5F of the rotor 5.

[0047] 11, one or more connecting portions 3F are provided in the communication passage 3E. The connecting portions 3F are portions that connect one circumferential end side and the other circumferential end side of the communication passage 3E. Specifically, in FIG. 11, each connecting portion 3F is a portion that connects the right side and the left side of the communication passage 3E.

[0048] Therefore, a portion 3H of the communication passage 3E (hereinafter referred to as a communication port 3H) is in communication with the slot 3D and the magnetic gap Ag. In this embodiment, the communication ports 3H and the connecting portions 3F are arranged alternately in the axial direction.

[0049] 12, the communication port 3H is formed by a recess 3J formed by recessing a portion of the electromagnetic steel sheet 3C in the thickness direction. The connecting portion 3F is provided at the bottom of the recess 3J. Therefore, the thickness dimension T3 of the connecting portion 3F is smaller than the thickness dimension T4 of the electromagnetic steel sheet 3C.

[0050] At least a part of the connecting portion 3F is provided with a modified portion 3K having a lower magnetic permeability than other portions. In this embodiment, as shown in Fig. 10, the dimension W1 between one circumferential end and the other circumferential end of the modified portion 3K is larger than the gap dimension G1 of the magnetic gap Ag.

[0051] The manufacturing method of the modified region 3K and the recessed region 3J is the same as the manufacturing method of the modified region 7E and the recessed region 7D of the rotor core 5A. The inner peripheral surface 3G of the stator 3 projected onto a virtual plane perpendicular to the axial direction, that is, the inner peripheral surface 3G shown in FIG. 11, has a smooth circumferential shape.

[0052] Furthermore, when the slot direction is defined as a direction passing through the width center of the slot 3D and perpendicular to the inner surface 3G of the stator 3, the modified portion 3K projected onto the imaginary plane is located within the slot 3D projected onto the imaginary plane perpendicular to the slot direction.

[0053] 11 corresponds to the imaginary plane. Therefore, the above configuration can be restated as follows: the modified region 3K shown in FIG. 12 is located within the slot 3D shown in FIG. <3.2 Oil supply to the stator> The oil pumped from the pump P is distributed and injected into the multiple slots 3D as shown in Figure 9. A portion of the oil flowing through each slot 3D flows out into the magnetic gap Ag from the communication passage 3E, that is, the communication port 3H.

[0054] The oil flowing out from the stator core 3A is collected in an oil pan Op or the like together with the oil flowing out from the rotor core 5A, and then flows into the oil cooler Ex to be cooled. The cooled oil is sucked into the pump P and is again pumped toward the rotor core 5A and the stator core 3A.

[0055] 4. Features of the rotor according to this embodiment In the motor 1 according to this embodiment, the winding 3B and the stator 3 are cooled by cooling oil, so that temperature increases in the winding 3B and the stator 3 can be suppressed.

[0056] In the rotor 5 of the motor 1, cooling oil flows through the reluctance section 7 provided close to the outer peripheral surface 5F of the rotor 5, so that the outer peripheral surface 5F side of the rotor core 5A can be effectively cooled.

[0057] The rotor 5 is provided with a recess 7D (hereinafter also referred to as oil passage 7D) that functions as an oil passage that connects the coolant passage 7A and the outer peripheral surface 5F of the rotor core 5A, thereby making it possible to directly cool the outer peripheral surface 5F of the rotor core 5A.

[0058] In this embodiment, cooling oil also flows into the magnetic gap Ag from the stator 3, so that the outer peripheral surface 5F of the rotor core 5A can also be cooled by this oil. Therefore, in this embodiment, the outer peripheral surface 5F side of the rotor 5 can be effectively cooled.

[0059] The oil passage 7D is located on the end side of the reluctance section 7 in the extension direction when projected onto an imaginary plane perpendicular to the axial direction. The end side of the reluctance section 7 in the extension direction is the location closest to the outer peripheral surface 5F of the rotor 5. Therefore, if the oil passage 7D is provided on the end side, it may be possible to easily supply oil to the outer peripheral surface 5F.

[0060] The bridge portion 7C ensures the strength of the rotor core 5A by connecting the portion on one side to the portion on the other side of the reluctance portion 7. However, if the magnetic permeability of the bridge portion 7C is high, the function of the reluctance portion 7 as a magnetic resistance portion is reduced.

[0061] In contrast, in this embodiment, a modified portion 7E is provided at the bottom of recess 7D, which forms the oil passage. Therefore, in the rotor 5, the strength of the rotor core 5A is ensured and the magnetic resistance function of the reluctance portion 7 is prevented from being significantly impaired.

[0062] Similarly, if the magnetic permeability of the connecting portion 3F is large, its function as a magnetic resistance portion will be reduced, and the magnetic flux induced in the stator 3 may form a closed loop within the stator 5 without flowing through the rotor 5.

[0063] In contrast, the thickness T3 of the coupling portion 3F according to this embodiment is smaller than the thickness T4 of the electromagnetic steel sheet 3C, and therefore the magnetic resistance is larger than that of other portions. Therefore, the magnetic flux induced in the stator 3 can be prevented from drawing a closed loop within the stator 5.

[0064] Furthermore, since at least a part of the connecting portion 3F is the modified portion 3K, the magnetic resistance of the connecting portion 3F is greater than that of other portions. Therefore, the magnetic flux inside the stator 5 can be reliably prevented from forming a closed loop.

[0065] Incidentally, if the slot 3D and the magnetic gap Ag are in communication with each other via the communication passage 3E, there is a high possibility that the portion of the stator 3 where the communication passage 3E is provided will vibrate. In contrast, the motor 1 is provided with a connecting portion 3F that connects one circumferential end side and the other circumferential end side of the communication passage 3E, so that it is possible to suppress vibrations from occurring in the area where the communication passage 3E is provided.

[0066] The inner peripheral surface 3G of the stator 3 projected onto an imaginary plane perpendicular to the central axis of rotation Lo of the rotor 5 has a smooth circumferential shape (see FIG. 10). This can prevent the resistance when the rotor 5 rotates inside the stator 3 from becoming excessively large.

[0067] In the motor 1, oil is supplied to the magnetic gap Ag. This places the rotor 5 and the stator 3 in a relationship similar to that of a shaft and a plain bearing (slide bearing). In other words, the rotor 5 corresponds to the shaft, and the inner circumferential surface 3G of the stator 3 corresponds to the plain bearing (also called metal).

[0068] Therefore, even when the rotor 5 rotates at high speed, the centrifugal force acting on the shaft 5D due to eccentricity can be absorbed by the oil present in the magnetic gap Ag, so that the rotor 5 can be rotated stably at high speed.

[0069] The plurality of coolant passages 7A and the plurality of slots 3D through which cooling oil flows are arranged at approximately equal intervals along the circumferential direction (see FIG. 1). Therefore, in this embodiment, oil can be supplied to the entire magnetic gap Ag.

[0070] As a result, it may be possible to cool the entire outer peripheral surface 5F of the rotor 5. Furthermore, since the occurrence of an imbalance in oil pressure can be suppressed in the multiple coolant passages 7A, it is possible to suppress a significant loss of rotational balance of the rotor core 5A.

[0071] (Other embodiments) The reluctance sections 7 and 8 according to the above-described embodiments have a smoothly curved, generally arc-shaped configuration. However, the present disclosure is not limited to this. For example, the reluctance sections may have a polygonal curved shape, i.e., a shape formed by joining multiple linear segments.

[0072] In the above-described embodiment, a bonded magnet is used as the permanent magnet M. However, the present disclosure is not limited to this. That is, in the present disclosure, for example, a sintered magnet or the like may be used in a reluctance section shaped like one or more connected linear sections.

[0073] In the above-described embodiment, the modified portion is formed by laser modification. However, the present disclosure is not limited to this. That is, the present disclosure may also be modified using, for example, an electron beam.

[0074] The recesses 7D according to the above-described embodiment are provided on one and the other sides of the electromagnetic steel sheet 5E in the thickness direction. However, the present disclosure is not limited to this. That is, the present disclosure may be configured such that the recesses 7D are provided only on one or the other side of the electromagnetic steel sheet 5E in the thickness direction, for example.

[0075] The modified portion 7E according to the above embodiment is provided only in a portion of the recess 7D. However, the present disclosure is not limited to this. That is, the present disclosure may be configured such that, for example, the entire bottom of the recess 7D is modified, the entire periphery of the recess 7D is modified, or the modified portion is eliminated.

[0076] In the above-described embodiment, the recesses 3J constituting the communication ports 3H are provided on one and the other sides in the thickness direction of the electromagnetic steel sheet 3C. However, the present disclosure is not limited to this. That is, the present disclosure may be configured such that, for example, the recesses 3J are provided only on one or the other side in the thickness direction of the electromagnetic steel sheet 3C.

[0077] The connecting portion 3F according to the above-described embodiment is provided with a modified portion 3K. However, the present disclosure is not limited to this. That is, the present disclosure may be, for example, configured such that the modified portion 3K is eliminated and the thickness T3 of the connecting portion 3F is smaller than the thickness T4 of the electromagnetic steel sheet 3C, or may be configured such that the modified portion 3K is eliminated and the thickness T3 and the thickness T4 are the same.

[0078] In the above-described embodiment, the rotor core 5A is provided with an oil passage formed by the recess 7D. However, the present disclosure is not limited to this. That is, the present disclosure may be configured such that, for example, the oil passage, i.e., the recess 7D, is eliminated.

[0079] In the above-described embodiment, the coolant passage 7A is provided only in the reluctance section 7. However, the present disclosure is not limited to this. That is, the present disclosure may be, for example, a configuration in which the coolant passage 7A is also provided in the reluctance section 8, a configuration in which the coolant passage 7A is provided only in some of the reluctance sections 7 and 8, or a configuration in which the coolant passage 7A is eliminated.

[0080] In the above-described embodiment, the communication passage 3E of the stator 3 is provided with a connecting portion 3F that connects one circumferential end and the other circumferential end of the communication passage 3E. However, the present disclosure is not limited to this. That is, the present disclosure may be configured such that the connecting portion 3F is eliminated, for example.

[0081] In the above-described embodiment, the dimension W1 between one circumferential end and the other circumferential end of the modified portion 3K of the stator 3 is larger than the gap dimension G1 of the magnetic gap Ag. However, the present disclosure is not limited to this. That is, in the present disclosure, for example, the dimension W1 may be equal to or smaller than the gap dimension G1.

[0082] In the above-described embodiment, oil is supplied to the magnetic gap Ag from both the stator 3 and the rotor 5. However, the present disclosure is not limited to this. That is, the present disclosure may be configured, for example, such that oil is supplied to the magnetic gap Ag from the stator 3 or the rotor 5, or such that a separate supply is provided to supply oil to the magnetic gap Ag.

[0083] In the above-described embodiment, a wet configuration is used in which oil is supplied to the magnetic gap Ag from both the stator 3 and the rotor 5. However, the present disclosure is not limited to this. That is, the present disclosure may be, for example, a dry configuration in which oil is not supplied to the magnetic gap Ag.

[0084] In the above-described embodiment, the permanent magnets M are embedded in the reluctance section 8. However, the present disclosure is not limited to this. That is, in the present disclosure, for example, the reluctance section 8 may be formed of an air gap.

[0085] In the above-described embodiment, the connecting portion 3F is provided to connect one circumferential end and the other circumferential end of the communication passage 3E. However, the present disclosure is not limited to this. That is, the present disclosure may be configured such that the connecting portion 3F is eliminated, for example.

[0086] In the above-described embodiment, the coolant passage, i.e., the hole 7A, is configured so that the cooling oil flows in from one axial end of the rotor core 5A and flows toward the other axial end, but the present disclosure is not limited to this.

[0087] That is, the disclosure may be configured such that, for example, cooling oil flows into rotor core 5A from the middle portion of shaft 5D in the longitudinal direction, and then branches off to one end side and the other end side in the axial direction.

[0088] Furthermore, the present disclosure is not limited to the above-described embodiments as long as it conforms to the spirit of the disclosure described in the above-described embodiments. Therefore, the present disclosure may be a configuration in which at least two of the above-described embodiments are combined, or a configuration in which any of the components illustrated or described with reference numerals in the above-described embodiments is eliminated. [Explanation of symbols]

[0089] 1... Reluctance motor 3... Stator 3A... Stator core 3C...Electromagnetic steel plate 3B...Winding 3D...Slot 3E…Communication path 3F…Connection part 3H…Communication port 3J... Recess 3K... Modified part 5... Rotor 5A... Rotor core 5B, 5C... End plates 5E... Electromagnetic steel plate 5D... Shaft 7, 8... Reluctance section 7A... Coolant passage 7C... Bridge portion 7D... Recess 7E... Reforming section 8... Reluctance section

Claims

1. a stator; a rotor that rotates within the stator; an oil supply unit that supplies oil to a gap between an inner peripheral surface of the stator and an outer peripheral surface of the rotor;

2. The rotor has: a coolant passage through which oil for cooling the rotor flows; and an oil passage is provided that connects the coolant passage with the outer circumferential surface of the rotor; 2. The electric motor according to claim 1, wherein the oil supply section is configured to include at least the oil passage.

3. The stator includes: a plurality of slots for receiving windings that induce a rotating magnetic field; and a communication passage is provided that communicates at least one of the plurality of slots with the gap; 2. The electric motor according to claim 1, wherein cooling oil flows through the slot, and the oil supply section includes at least the communication passage.

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