rotating electrical machines

Abstract

A rotating electric machine improved in terms of contamination in a water channel provided in a motor frame. [Solution] A rotating electric machine has a motor frame that covers and houses a stator from the radial outside, the motor frame having a water channel through which a refrigerant flows in a circumferential direction, a first protrusion and a second protrusion that protrude radially outward from the outer peripheral surface of the motor frame and extend from one axial side end of the motor frame to the other axial side to reinforce the motor frame, an inlet for the refrigerant to the water channel that protrudes at least radially outward from the first protrusion, and an outlet for the refrigerant to the water channel that protrudes at least radially outward from the second protrusion, the first protrusion having a first hollow portion that opens at one axial side end and extends axially to the other axial side at least to the axial position of the inlet, and the second protrusion having a second hollow portion that opens at one axial side end and extends axially to the other axial side at least to the axial position of the outlet.

Description

[Technical Field]

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

[0002] Conventionally, structures for cooling a rotating electric machine have been known. Patent Document 1 discloses a structure for cooling an electric motor by providing a refrigerant flow path in a housing that accommodates the starter of the electric motor so as to cover the starter from the radial outside. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-222984 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, when a water channel is provided to allow the refrigerant to flow around the circumferential direction of the motor frame, which is the part that covers the stator, as in the housing described in Patent Document 1, by providing an inlet for supplying the refrigerant to the water channel and an outlet for discharging the refrigerant from the water channel, the refrigerant cooled outside can be circulated within the motor frame using a pump or the like.

[0005] To provide the water passages, inlets, and outlets within the motor frame, it is conceivable to manufacture the motor frame by die-casting and form the inlets and outlets as cast holes or by machining. Furthermore, to reduce the axial size of the motor, it is desirable to position the inlets and outlets radially outward from the motor frame. Patent Document 1 did not consider positioning the inlets and outlets radially outward from the motor frame.

[0006] When inlet and outlet holes are formed by cutting from the radial outside of the motor frame using a drill or other cutting process, the holes must reach the water channels inside the motor frame. However, because the water channels inside the motor frame are located in a thin section that covers the stator of the motor frame, it is difficult to adjust the depth of the holes drilled using a drill or other cutting process. If the holes are drilled too deep, they will penetrate through the section that covers the stator of the motor frame, and if they are too shallow, they will not reach the water channels inside the motor frame. Therefore, it is desirable to form the inlet and outlet holes using cast holes.

[0007] On the other hand, when forming the inlets and outlets using cast-out holes, an inlet / outlet mold is used to form the inlet and outlet holes by casting out, and a water channel mold is used to form the water channels in the motor frame by casting out. In this case, there is a concern that burrs may occur inside the water channels at the mating surfaces of the inlet / outlet mold and the water channel mold, which may cause contamination inside the water channels. "Contamination" is an abbreviation of "contamination."

[0008] The present invention has been made in view of the above points, and an object of the present invention is to provide a rotating electric machine in which contamination in a water channel provided in a motor frame is improved. [Means for solving the problem]

[0009] A rotating electric machine according to one aspect of the present invention includes a stator, a rotor disposed radially inside the stator and facing the stator across an air gap, and a motor frame that accommodates the stator from the radially outside, the motor frame including a water passage through which a coolant flows in a circumferential direction, a first protruding portion and a second protruding portion that protrude radially outward from an outer peripheral surface of the motor frame and extend from one axial end of the motor frame to the other axial end to reinforce the motor frame, and a second protruding portion that protrudes at least radially outward from the first protruding portion. the first protrusion has an inlet into the water passage for the refrigerant to flow out, and an outlet into the water passage for the refrigerant protruding at least radially outward from the second protrusion, the first protrusion having a first cavity that opens at one axial end and extends axially to the other side at least to the axial position of the inlet, the second protrusion having a second cavity that opens at one axial end and extends axially to the other side at least to the axial position of the outlet, the inlet communicating with the water passage via the first cavity, and the outlet communicating with the water passage via the second cavity. [Effects of the Invention]

[0010] According to one aspect of the present invention, it is possible to provide a rotating electric machine in which contamination in a water channel provided in a motor frame is improved. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a perspective view of a motor 100 according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a side cross-sectional view of the motor 100. [Figure 3] FIG. 2 is a perspective view of the motor frame 400 and the stator 200 as viewed from one axial side. [Figure 4] 4 is a diagram illustrating a mold for casting holes for an inlet 402 and an outlet 404. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, a rotating electric machine according to an embodiment of the present invention will be described with reference to the drawings. In the drawings, the scale and number of components may differ from the actual structure in order to make each component easier to understand.

[0013] <Embodiment 1> 1 is a perspective view of a motor 100 according to a first embodiment of the present invention. The motor 100 rotates around a shaft 310 that extends along a central axis J. The motor 100 is an example of a rotating electric machine.

[0014] Hereinafter, the direction parallel to the central axis J will be referred to as the axial direction. In the axial direction, the side extending upward in FIG. 1 will be referred to as the "one side," and the side extending downward in FIG. 1 will be referred to as the "other side." Note that the terms "one side" and "other side" are names used merely for the purpose of explanation and do not limit the actual positional relationship or direction. Furthermore, unless otherwise specified, the radial direction centered on the central axis J will be simply referred to as the "radial direction," and the circumferential direction centered on the central axis J, i.e., around the axis of the central axis J, will be simply referred to as the "circumferential direction." In the radial direction, the side closer to the central axis J will be referred to as the "radially inner side," and the side away from the central axis J will be referred to as the "radially outer side." In the circumferential direction, the clockwise side when viewed from one axial side will be referred to as the "one circumferential side," and the counterclockwise side will be referred to as the "other circumferential side."

[0015] In this specification, "extending in the axial direction" includes not only extending strictly in the axial direction but also extending in a direction tilted by less than 45° with respect to the axial direction. Furthermore, in this specification, "extending in the radial direction" includes not only extending strictly in the radial direction, i.e., in a direction perpendicular to the axial direction, but also extending in a direction tilted by less than 45° with respect to the radial direction. Furthermore, "parallel" includes not only being strictly parallel but also being tilted by an angle of less than 45° with respect to the direction perpendicular to the axial direction. Furthermore, "extending in a direction perpendicular to the axial direction" includes not only extending in a direction perpendicular to the axial direction but also extending in a direction tilted by less than 45° with respect to the direction perpendicular to the axial direction.

[0016] The motor 100 includes a stator 200, a rotor 300 disposed radially inside the stator 200 across an air gap, and a shaft 310 fixed to the radially inside of the rotor 300 and extending along a central axis J. The stator 200 has a coil end 220 (see FIG. 2) at one axial end and a coil end 210 at the other axial end.

[0017] The motor 100 also has a motor frame 400 that covers the stator 200 from the radial outside, and a bracket 500 that closes an opening on one axial side of the motor frame 400. The motor frame 400 accommodates the stator 200, the rotor 300, and the shaft 310 by covering the stator 200 from the radial outside. The bracket 500 is fixed to one axial end of the motor frame 400 with a plurality of bolts 501.

[0018] The motor frame 400 has protrusions 401 and 403 that protrude radially outward from its outer circumferential surface. An inlet 402 is provided in the protrusion 401, and an outlet 404 is provided in the protrusion 403. The inlet 402 and the outlet 404 are substantially cylindrical. The circumferential position of the protrusion 401 does not coincide with the circumferential position of the protrusion 403. The circumferential position of the inlet 402 does not coincide with the circumferential position of the outlet 404. The hole of the inlet 402 is a cylindrical bore of the inlet 402, which is cylindrical. The cylindrical bore of the outlet 404 is a cylindrical bore of the outlet 404, which is cylindrical.

[0019] Fig. 2 is a side cross-sectional view of motor 100. Fig. 2 is a cross-sectional view of motor 100 taken along a cutting plane parallel to central axis J that passes through central axis J and passes through the vicinity between protruding portion 401 and protruding portion 403 in the circumferential direction.

[0020] The motor frame 400 has a water channel 410 whose one circumferential end communicates with the hole of the inlet 402 and whose other circumferential end communicates with the hole of the outlet 404. The water channel 410 opens on one axial side and extends on the other axial side, circumferentially from the inlet 402 to the outlet 404. The hole of the inlet 402, the hole of the outlet 404, and the water channel 410 form a water channel through which a coolant that cools the motor 100 circulates. The inlet 402 is an inlet that supplies the coolant to the water channel 410. The outlet 404 is an outlet that discharges the coolant from the water channel 410. The coolant flowing through the water channel 410 cools the stator 200 covered by the motor frame 400.

[0021] FIG. 3 is a perspective view of the motor frame 400 and the stator 200 as viewed from one axial side. The protruding portion 401 is hollow and has a cavity 401c that is open only at one axial end. The protruding portion 401 has a substantially triangular cylindrical shape extending from one axial end of the motor frame 400 to an inlet 402 on the other axial side. The protruding portion 401 functions as a reinforcing member that reinforces the cylindrical portion of the motor frame 400 that covers the stator 200 from the radial outside. The protruding portion 403 is hollow and has a cavity 403c that is open only at one axial end. The protruding portion 403 has a substantially triangular cylindrical shape extending from one axial end of the motor frame 400 to an outlet 404 on the other axial side. The protruding portion 403 functions as a reinforcing member that reinforces the cylindrical portion of the motor frame 400 that covers the stator 200 from the radial outside. At least one of the protrusions 401 and 403 may extend from one axial end to the other axial end of the motor frame 400. In this way, the rigidity of the motor frame 400 can be further increased.

[0022] The protrusion 401 forms a triangle of a triangular tube by three surfaces: the outer peripheral surface of a cylindrical portion of the motor frame 400 that covers the stator 200 from the radial outside, and surfaces 401a and 401b that protrude radially outward from the outer peripheral surface. The hollow portion 401c is a cylindrical hole in the protrusion 401, which is a triangular tube. Surface 401a is a surface on one circumferential side of surface 401b. The inlet 402 is provided in surface 401a. The radially inner end of the hole of the inlet 402 communicates with the hollow portion 401c. The hollow portion 401c communicates with one circumferential end of the water channel 410. The radially inner end of the hole of the inlet 402 communicates with one circumferential end of the water channel 410 via the hollow portion 401c. The hollow portion 401c is a water channel through which a refrigerant flows. The hole of the inlet 402 extends from the hollow portion 401c radially outward in a direction perpendicular to the surface 401a. The radially outer end of the hole of the inlet 402 opens radially outward. The radially outer end of the hole of the inlet 402 is connected to a pump (not shown) for circulating the refrigerant. The inlet 402 may be provided on the surface 401b.

[0023] The protrusion 403 forms a triangle of the triangular cylinder by three surfaces: the outer peripheral surface of the cylindrical portion of the motor frame 400 that covers the stator 200 from the radial outside, and surfaces 403a and 403b that protrude radially outward from the outer peripheral surface. The hollow portion 403c is a cylindrical hole of the protrusion 403, which is a triangular cylinder. Surface 403a is on one circumferential side of surface 403b. The outlet 404 is provided in surface 403b. The radially inner end of the hole of the outlet 404 communicates with the hollow portion 403c. The hollow portion 403c communicates with the other circumferential end of the water channel 410. The radially inner end of the hole of the outlet 404 communicates with the other circumferential end of the water channel 410 via the hollow portion 403c. The hollow portion 403c is a water channel through which the refrigerant flows. The hole of outlet 404 extends from hollow portion 403c radially outward in a direction perpendicular to surface 403b. The radially outer end of the hole of outlet 404 opens radially outward. The radially outer end of the hole of outlet 404 is connected to a pump (not shown) for circulating the refrigerant. Outlet 404 may be provided on surface 403a.

[0024] Bracket 500 is fixed to one axial end of motor frame 400, thereby closing water channel 410, cavity 401c, and the opening on one axial side of cavity 401c. One circumferential end of water channel 410 communicates with cavity 401c, thereby communicating with the hole of inlet 402. The other circumferential end of water channel 410 communicates with cavity 403c, thereby communicating with the hole of outlet 404.

[0025] The motor frame 400 is manufactured by, for example, die casting. When manufacturing the motor frame 400, a water channel mold is used to form the hollow portion 401c, the hollow portion 403c, and the water channel 410 by casting. The mold for the water channel is cast off in one axial direction.

[0026] FIG. 4 is a diagram illustrating molds used to cast out the holes for the inlet 402 and the outlet 404. In this embodiment, in addition to a water passage mold, an outlet mold 610 and an inlet mold 620 shown in FIG. 4 are used when manufacturing the motor frame 400. The outlet mold 610 is a mold used to form the hole for the outlet 404 by casting out. The direction of the mold removal from the outlet mold 610 is parallel to the hole for the outlet 404 and extends radially outward. The inlet mold 620 is a mold used to form the hole for the inlet 402 by casting out. The direction of the mold removal from the inlet mold 620 is parallel to the hole for the inlet 402 and extends radially outward.

[0027] However, burrs may occur in the water channel at the mold mating surfaces between the outlet mold 610 or the inlet mold 620 and the water channel mold. Conventionally, no consideration has been given to burrs on these mold mating surfaces. As a result, the motor is driven with the burrs remaining, and if the burrs come off, they can become contaminants in the water channel. Furthermore, even if an attempt is made to remove the burrs before driving the motor, there is no operating area for a burr removal tool.

[0028] The motor frame 400 according to this embodiment is configured so that burrs can be removed from the mating surfaces of the outlet mold 610 and the inlet mold 620 and the water channel mold before the motor 100 is driven.

[0029] Burrs on the mating surfaces of the outlet mold 610, the inlet mold 620, and the waterway mold are formed at the interface between the hole of the outlet 404 and the cavity 403c, and at the interface between the hole of the inlet 402 and the cavity 401c. Therefore, in this embodiment, the cavity 403c is provided with a width sufficient to insert a burr removal tool from one axial direction relative to the interface between the hole of the outlet 404 and the cavity 403c and ensure at least an operating area for the tool. Furthermore, the cavity 401c is provided with a width sufficient to insert a burr removal tool from one axial direction relative to the interface between the hole of the inlet 402 and the cavity 401c and ensure at least an operating area for the tool. The burr removal tool is, for example, a file used to remove burrs. That is, the width of the cavity 403c from the interface between the hole of the outlet 404 and the cavity 403c in a direction perpendicular to this interface is sufficient to insert and operate the burr removal tool. Furthermore, the width of cavity 401c from the boundary between the hole of inlet 402 and cavity 401c in a direction perpendicular to this boundary is a width that ensures at least an operating area for inserting and manipulating a burr removal tool. Burrs removed with the burr removal tool can be washed away, for example, before fixing bracket 500 to one axial side of motor frame 400. In this way, no burrs are present when motor 100 is running, and contamination inside water channel 410 can be prevented.

[0030] The present invention is not limited to the above-described embodiments, and various improvements and design changes may be made without departing from the spirit of the present invention. In addition, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0031] 100...Motor 200...Stator 300...Rotor 310...shaft 400...Motor frame 500…Bracket

Claims

1. a stator; a rotor disposed radially inside the stator and facing the stator across an air gap; and a motor frame that covers and houses the stator from the radially outside, the motor frame has a water channel through which a refrigerant flows in a circumferential direction, a first protruding portion and a second protruding portion that protrude radially outward from an outer peripheral surface of the motor frame and extend from one axial end of the motor frame to the other axial end to reinforce the motor frame, an inlet for the refrigerant into the water channel that protrudes at least radially outward from the first protruding portion, and an outlet for the refrigerant into the water channel that protrudes at least radially outward from the second protruding portion, the first protruding portion has a first cavity portion that opens at one axial end and extends to the other axial end at least to the axial position of the inlet, the second protruding portion has a second cavity portion that opens at one axial end and extends to the other axial end at least to the axial position of the outlet, the inlet communicates with the water channel via the first cavity; The outlet communicates with the water channel via the second cavity. A rotating electric machine characterized by:

2. At least one of the first cavity portion and the second cavity portion extends from one axial end of the motor frame to the other axial end of the motor frame.

2. The rotating electrical machine according to claim 1.

3. a bracket that closes one axial side of the motor frame; 2. The rotating electrical machine according to claim 1.

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