Rotary electric machine

Abstract

This rotary electric machine includes a stator and a rotor and comprises a housing that covers the stator and the rotor, wherein: the stator comprises an annular stator core and a coil that is inserted into the stator core and has a coil end protruding from an end surface of the stator core to the outside of the stator core; the housing includes an annular supply path formed by a first wall and a second wall provided radially inward of the first wall, and a discharge path for discharging a medium circulating in the supply path to the coil end; and the discharge path is formed by a release end that is an end surface of the second wall protruding toward the stator core in a cross section, and an end surface of the stator core.

Description

rotating electrical machines

[0001] The present invention relates to a rotating electric machine.

[0002] As motors become more powerful, the demand for cooling coils increases, and one known method for improving cooling efficiency is to apply refrigerant oil directly to the coil ends. Regarding such a cooling method, for example, Patent Document 1 discloses a technology in which, in a motor, an annular refrigerant flow path 43 is defined that is surrounded by a notch 42 in a resin molded portion 31, an end face 3A of the stator 3 in the direction of the rotation axis O, and the inner circumferential surface of the housing 4, thereby supplying refrigerant to both the end face of the stator 3 and the coil ends, thereby improving cooling efficiency while preventing the motor from becoming larger.

[0003] Japanese Patent Application Laid-Open No. 2005-354821

[0004] In conventional technology, direct cooling of the coil ends with a coolant requires the creation of new coolant outlet holes in the cooling jacket of the housing, and in order to cool all of the coil ends arranged around the stator, multiple outlet holes must be drilled in the housing, which increases processing costs and reduces the strength of the housing.

[0005] A rotating electric machine having a stator and a rotor, and a housing that covers the stator and the rotor, wherein the stator comprises an annular stator core, and a coil inserted into the stator core and having a coil end protruding from an end face of the stator core to the outside of the stator core, and the housing comprises an annular supply passage formed by a first wall and a second wall provided radially inward from the first wall, and a discharge passage that discharges a medium circulating within the supply passage to the coil end, and the discharge passage is formed in cross section by an open end that is the end face of the second wall that protrudes toward the stator core, and the end face of the stator core.

[0006] According to the present invention, it is possible to provide a rotating electric machine that achieves cost reduction, improved housing strength, improved cooling performance, and miniaturization.

[0007] 1A is an enlarged view of A in FIG. 1; FIG. 2B is an overall view of the supply passage in the circumferential direction in accordance with an embodiment of the present invention; FIG. 3 is an explanatory view of the discharge passage in accordance with an embodiment of the present invention;

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and some omissions and simplifications have been made as appropriate for clarity of explanation. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0009] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0010] (One embodiment and overall configuration) (Fig. 1) A motor 100 includes a rotor 14 and a stator. The rotor 14 and the stator are covered by a housing 1. The stator has a stator core 5 and coils 2. The stator core 5 is formed in an annular shape in the circumferential direction and has a plurality of slots (not shown) in the circumferential direction, with a coil 2 inserted in each slot. A supply passage 8 for cooling the stator is formed in the axial direction on the outer periphery of the stator core 5.

[0011] (Fig. 2) The coil 2 (Fig. 1) of the stator core 5 has coil ends 2a at both axial ends. The coil ends 2a protrude from both axial end surfaces of the stator core 5 to the outside of the stator core 5. The housing 1 has a first wall 3 and a second wall 4 provided on the inner circumferential side of the first wall 3. The supply passage 8 is a flow path through which a refrigerant that cools the motor 100 flows, and is formed in the radial direction by the first wall 3 and the second wall 4.

[0012] The supply passage 8 is formed in a ring shape in the circumferential direction as shown in Fig. 3. The supply passage 8 also extends in the axial direction on the outer periphery of the stator core 5 (see Fig. 1), thereby enabling the refrigerant to be supplied to both axial sides of the stator core 5.

[0013] The stator core 5 is fixed to the housing 1 by a fixing portion 6, and is disposed so as to encroach on a part of the supply passage 8 extending in the axial direction. The fixing portion 6 is, for example, a bolt, and is provided radially inward of the first wall 3. This allows the motor 100 to be made smaller.

[0014] The supply path 8 has a shift portion 7 that is aligned with the location in the circumferential direction where the fixed portion 6 is provided. This allows the supply path 8 to be formed in the circumferential direction so as to avoid the fixed portion 6, thereby making it possible to reduce the size.

[0015] (Fig. 3) Fig. 3 illustrates the supply passages 8 formed in the circumferential direction of the rotating electric machine 100, but does not illustrate the flow paths provided in the axial direction on the outer periphery of the stator core 5 and the supply passages 8 formed on the opposite side of the stator core 5 in Fig. 2. Also, the circumferential supply passages 8 are illustrated alone to clearly show their shape, but as mentioned above, the supply passages 8 are actually spaces formed between the first wall 3 and the second wall 4 inside the motor housing 1.

[0016] The coolant to be circulated inside the supply path 8 flows in through a coolant supply port 8 a. The supply path 8 also has a shift portion 7 that is shifted in the axial direction to avoid the fixed portion 6 in accordance with the shape of the fixed portion 6, thereby preventing the rotary electric machine 100 from becoming larger in the axial direction and contributing to miniaturization.

[0017] (Fig. 4) The supply passages 8 have discharge passages 9 extending radially inward. The discharge passages 9 are formed along the supply passages 8 extending circumferentially. The discharge passages 9 extend vertically and radially inward relative to the supply passages 8 extending axially. The refrigerant is discharged to the coil ends 2a located radially inward of the discharge passages 9, thereby directly cooling the coils 2.

[0018] In cross section, the discharge passage 9 is formed by an open end 10, which is an end face of the second wall 4 formed to protrude toward the stator core 5, and a core end face 11, which is an end face of a portion of the stator core 5. Although not shown, the discharge passage 9 may also be formed in the shift portion 7 (FIGS. 2 and 3) of the supply passage 8 in a similar manner.

[0019] As a result, when forming the discharge passage 9 for directly cooling the coil 2 to improve heat dissipation efficiency, the discharge passage 9 is formed by the housing 1 (open end 10) and the stator core 5 (core end face 11), which eliminates the need to drill new holes in the housing 1 and contributes to improving the strength and reducing costs of the housing 1. Furthermore, the discharge passage 9 can be designed with a high degree of freedom in the circumferential direction in areas other than the fixed portion 6.

[0020] Furthermore, due to the arrangement of the stator core 5 fixed to the housing 1 by the fixing portion 6, the first distance 12, which is the distance from the first wall 3 to the outer peripheral surface of the stator core 5, is shorter than the distance from the first wall 3 to the second distance 13, which is the radial size of the supply path 8. This contributes to the miniaturization of the motor 100.

[0021] According to the embodiment of the present invention described above, the following advantageous effects are achieved.

[0022] (1) A rotating electric machine (100) includes a housing (1) that has a stator (14) and a rotor (14) and covers the stator and rotor. The stator includes an annular stator core (5) and a coil (2) that is inserted into the stator core (5) and has coil ends (2a) that protrude from an end face of the stator core (5) to the outside of the stator core (5). The housing (1) includes an annular supply passage (8) formed by a first wall (3) and a second wall (4) disposed radially inward from the first wall (3), and a discharge passage (9) that discharges a medium circulating in the supply passage (8) to the coil ends (2a). The discharge passage (9) is defined in cross section by an open end (10) that is the end face of the second wall (4) that protrudes toward the stator core (5), and an end face (11) of the stator core (5). This configuration makes it possible to provide a rotating electric machine (100) that achieves reduced costs, improved housing strength, improved cooling performance, and compact size.

[0023] (2) In the radial direction, a first distance 12, which is the distance from the first wall 3 to the outer peripheral surface of the stator core 5, is smaller than a second distance 13, which is the distance from the first wall 3 to the second wall 4. This contributes to miniaturization.

[0024] (3) The discharge passage 9 is provided vertically and radially inward relative to the supply passage 8, which is provided in the axial direction. This improves the cooling effect.

[0025] (4) The stator core 5 is provided with a fixed portion 6 that fixes the stator core 5 to the housing 1, and the supply passage 8 is provided with a shift portion 7 that is formed by shifting the supply passage 8 in the axial direction so as to avoid the fixed portion 6 in accordance with the shape of the fixed portion 6. This contributes to miniaturization.

[0026] The present invention is not limited to the above-described embodiments, and various modifications and combinations of other configurations are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited to those having all of the configurations described in the above-described embodiments, and includes those in which some of the configurations are omitted.

[0027] REFERENCE SIGNS LIST 1 Housing 2 Coil 2a Coil end 3 First wall 4 Second wall 5 Stator core 6 Fixed portion 7 Shift portion 8 Supply path 8a Refrigerant supply port 9 Discharge path 10 Open end 11 Core end face 12 First distance 13 Second distance 14 Rotor 100 Motor

Claims

1. A rotating electric machine having a stator and a rotor, and comprising a housing covering the stator and the rotor, wherein the stator comprises an annular stator core, and a coil inserted into the stator core and having a coil end protruding from an end face of the stator core to the outside of the stator core, wherein the housing comprises an annular supply passage formed by a first wall and a second wall provided radially inward from the first wall, and a discharge passage for discharging a medium circulating within the supply passage to the coil end, and wherein the discharge passage is formed in cross section by an open end, which is the end face of the second wall protruding toward the stator core, and an end face of the stator core.

2. A rotating electric machine according to claim 1, wherein a first distance, which is the distance from the first wall to the outer peripheral surface of the stator core in the radial direction, is smaller than a second distance, which is the distance from the first wall to the second wall.

3. A rotating electric machine according to claim 1, wherein the discharge passage is provided vertically and radially inwardly with respect to the supply passage which is provided in the axial direction.

4. A rotating electric machine as claimed in claim 2, further comprising a fixed portion for fixing the stator core to the housing, and the supply path further comprising a shift portion which is formed by shifting the supply path in the axial direction so as to avoid the fixed portion and conform to the shape of the fixed portion.

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