Rotating electric machines

Abstract

To provide a rotary electric machine with improved cooling of coils.SOLUTION: A rotary electric machine has a rotor having a shaft extending along a central axis, a stator disposed radially outward of the rotor through an air gap, and a frame accommodating the stator, the stator has a stator core and a coil for exciting the stator core, the frame has a groove on an inner circumferential surface facing the stator that is recessed radially outward from a position where it contacts an outer circumferential surface of the stator core, and the stator core has a plurality of slots that accommodate at least a portion of the coil and the first flow path, which is a refrigerant liquid flow path extending radially inward from the surface opposite the groove and leading to a portion of the coil that is accommodated in the plurality of slots.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Conventionally, there are known techniques for cooling the coil ends of rotating electrical machines. Patent Document 1 discloses a structure in which a stator core and coils are housed in an outer cylindrical ring, and guide vanes are provided on the outer periphery of the outer cylindrical ring to direct cooling oil toward the coil ends exposed from the outer cylindrical ring at the axial ends. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-222904 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in Patent Document 1, the cooling oil flows around the outer periphery of the outer cylindrical ring to cool the coil ends only, and there is no disclosure about cooling parts of the coil other than the coil ends. As a result, the coil cannot be cooled sufficiently, and there is room for improvement in coil cooling.

[0005] An object of the present invention is to provide a rotating electric machine with improved coil cooling. [Means for solving the problem]

[0006] A rotating electric machine according to one aspect of the present invention includes a rotor having a shaft extending along a central axis, a stator disposed radially outward of the rotor via an air gap, and a frame accommodating the stator, wherein the stator has a stator core and a coil for exciting the stator core, and the frame has, on an inner peripheral surface facing the stator, a groove portion recessed radially outward from a position where the frame contacts an outer peripheral surface of the stator core, and the stator core has a plurality of slots accommodating at least a portion of the coil, and a first flow path that is a flow path for refrigerant liquid extending radially inward from the surface facing the groove portion and continuing to portions of the coil accommodated in the plurality of slots. the coils have coil ends exposed from axial ends of the stator core, the stator core has second flow paths that are flow paths for refrigerant liquid extending axially from the first flow path and continuing to the coil ends, the stator core is formed by stacking a plurality of electromagnetic steel sheets in the axial direction, the plurality of electromagnetic steel sheets comprising first electromagnetic steel sheets that have radially outer ends of the first flow path and second electromagnetic steel sheets that do not have radially outer ends of the first flow path, the first electromagnetic steel sheets have bridge portions that connect the first electromagnetic steel sheets in the circumferential direction radially outer than the radially outer ends of the slots, the second electromagnetic steel sheets have the second flow paths that continue from the radially inner ends of the first flow paths to the radially outer ends of the slots, the second electromagnetic steel sheets have third flow paths that connect the radially inner ends of the second flow paths and the radially outer ends of the slots, and the circumferential width of the third flow path is narrower than the circumferential width of the slots. .

[0007] In the rotating electric machine according to one aspect described above, the groove portion extends over the entire circumference in the circumferential direction.

[0008] In the rotating electric machine according to the above aspect, the first flow passage is arranged for each of the plurality of slots. [Effects of the Invention]

[0011] According to one aspect of the present invention, it is possible to provide a rotating electric machine with improved cooling of the coil. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a perspective view of a motor according to a first embodiment of the present invention. [Figure 2] 2 is a cross-sectional side view of the motor 100 of FIG. 1 taken along a plane passing through the center axis J and perpendicular to the X axis, as viewed from the -X side. [Figure 3] 2 is a cross-sectional side view of the motor 100 of FIG. 1 taken along a plane that passes through the center of a flow path 122 and is perpendicular to the Z axis, as viewed from the -Z side. [Figure 4] FIG. 2 is a perspective view of the frame 101 of FIG. 1 as viewed from the -Y side. [Figure 5] FIG. 2 is a perspective view of a stator core 140 of FIG. [Figure 6]6 is a perspective cross-sectional view of the stator core 140 of FIG. 5 cut along a plane that passes through the center of a flow passage 141 and is perpendicular to the Z axis. [Figure 7] 6 is a perspective cross-sectional view of the stator core 140 of FIG. 5 cut along a plane that passes through the center of a flow passage 141 and is perpendicular to the X-axis. DETAILED DESCRIPTION OF THE INVENTION

[0013] 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.

[0014] In addition, in the drawings, an XYZ coordinate system is shown as a three-dimensional Cartesian coordinate system as appropriate. In the XYZ coordinate system, the Z axis direction is parallel to the axis of the central axis J shown in Figure 1. The Y axis direction is the radial direction relative to the central axis J, which is the up-down direction in Figure 2. The X axis direction is perpendicular to both the Z axis direction and the Y axis direction. In each of the X axis direction, the side indicated by the arrow in the drawing is the positive side, and the opposite side is the negative side.

[0015] In the following description, the positive side (+Z side) in the Z-axis direction will be referred to as "one side," and the negative side (-Z side) in the Z-axis direction will be referred to as "the other side." Note that "one side" and "the 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 direction parallel to the central axis J (Z-axis direction) will be referred to simply as "axial direction," the radial direction centered on the central axis J will be referred to simply as "radial direction," and the circumferential direction centered on the central axis J, i.e., around the axis of the central axis J, will be referred to simply as "circumferential direction." The side approaching the central axis J in the radial direction will be referred to as "radially inner," and the side away from the central axis J will be referred to as "radially outer."

[0016] In this specification, "extending in the axial direction" includes not only extending strictly in the axial direction (Z-axis direction) but also extending in a direction tilted by less than 45° with respect to the axial direction. In addition, 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 (Z-axis 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 each other.

[0017] First Embodiment FIG. 1 is a perspective view of a motor according to a first embodiment of the present invention. The motor 100 in FIG. 1 is an example of a rotating electric machine. The motor 100 includes a rotor 106 (see FIG. 2) having a shaft 110 extending along a central axis J, and a stator 107 (see FIG. 2) disposed radially outward of the rotor 106 via an air gap. The shaft 110 is rotatable around the central axis J.

[0018] Motor 100 has a frame 101 that houses stator 107, an end plate 102 arranged on the other axial side of frame 101, and an end plate 103 arranged on one axial side of frame 101. Frame 101 has an oil inlet 104 that supplies oil into motor 100. Frame 101 has an oil outlet 105 that discharges oil from inside motor 100. Oil is an example of a refrigerant liquid. In motor 100 of this embodiment, the coils are cooled with oil, but a rotating electric machine of the present invention may also cool the coils with a refrigerant liquid other than oil.

[0019] The frame 101 is a cylindrical member with both axial ends open. The frame 101 is made of, for example, die-cast aluminum. The end plate 102 is a plate-like member that closes an opening on the other axial side of the frame 101. The end plate 102 is fixed to the other axial side of the frame 101 by, for example, bolts. The end plate 102 is made of, for example, die-cast aluminum. The end plate 103 is a plate-like member that closes an opening on one axial side of the frame 101. The end plate 103 is fixed to the one axial side of the frame 101 by, for example, bolts. The end plate 103 is made of, for example, die-cast aluminum.

[0020] 2 is a side cross-sectional view of the motor 100 in FIG. 1 taken along a plane that passes through the central axis J and is perpendicular to the X axis, and is viewed from the -X side. The stator 107 has a stator core 140 and coils 150. The stator core 140 is fixed to the frame 101 by, for example, shrink fitting.

[0021] The motor 100 has a bearing 201 and a bearing 202. The other axial end of the shaft 110 is fixed to the inner ring of the bearing 201. The one axial end of the shaft 110 is fixed to the inner ring of the bearing 202. The outer ring of the bearing 201 is fixed to the end plate 102. The outer ring of the bearing 202 is fixed to the end plate 103. The shaft 110 is supported by the bearing 201 and the bearing 202 so as to be rotatable about the central axis J as the rotation axis.

[0022] The frame 101 has a flow path 120 into which oil flows from the oil inlet 104. The flow path 120 extends in the X-axis direction. The +X side end of the flow path 120 is connected to the oil inlet 104. The frame 101 has a flow path 121 extending in the axial direction. The -X side end of the flow path 120 is connected to the flow path 121. The flow path 121 penetrates the frame 101 in the axial direction. The oil that flows out from the -X side end of the flow path 120 flows into the flow path 121.

[0023] Frame 101 has a flow path 122 that is connected at its radially outer end to flow path 121 and extends radially inward. In this embodiment, the axial position of flow path 122 is the central position in the axial direction of stator core 140. This allows the vicinity of the axial center of coil 150 to be efficiently cooled by oil. Oil flowing through flow path 121 flows into flow path 122.

[0024] The frame 101 has a groove 123 on its inner circumferential surface 101a facing the stator 107, the groove 123 being recessed radially outward from a position where the frame 101 a comes into contact with the outer circumferential surface 146 (see FIG. 5 ) of the stator core 140. The radially inner end of the flow path 122 is connected to the groove 123. The groove 123 extends around the entire circumference. Oil flowing out from the radially inner end of the flow path 122 flows into the groove 123.

[0025] Stator core 140 has a plurality of slots 144 that accommodate at least a portion of coil 150. Coil 150 has accommodated coil 151 accommodated in slot 144 of stator core 140, coil end 152 exposed from the other axial end of stator core 140 on the other axial side, and coil end 153 exposed from the one axial end of stator core 140 on one axial side.

[0026] The stator core 140 has flow passages 141 extending in the radial direction. The radially outer end of the flow passage 141 faces the groove portion 123. Oil flowing through the groove portion 123 flows into the flow passage 141. The stator core 140 has flow passages 142 extending in the axial direction. The radially inner end of the flow passage 141 is connected to the flow passage 142. The flow passage 142 penetrates the stator core 140 in the axial direction. As will be described in detail later, the oil flows into the flow passage 142 from the radially inner end of the flow passage 141. The stator core 140 also has a crossover portion 143, which will be described in detail later. A plurality of the flow passages 141 are arranged in the circumferential direction, one for each of the plurality of slots 144.

[0027] End plate 102 has a flow path 131 that guides oil that has flowed out from the other axial end of flow path 121 to bearing 201. The oil supplied to bearing 201 through flow path 131 is used to lubricate bearing 201. End plate 103 has a flow path 132 that guides oil that has flowed out from one axial end of flow path 121 to bearing 202. The oil supplied to bearing 202 through flow path 132 is used to lubricate bearing 202.

[0028] 3 is a cross-sectional side view of motor 100 in FIG. 1 taken along a plane perpendicular to the Z axis and passing through the center of flow passage 122, as viewed from the -Z side. Oil that flows in through oil inlet 104 flows through the various flow passages described below within motor 100 and reaches oil pan 160. The oil in oil pan 160 is discharged to the outside through oil outlet 105.

[0029] Oil flowing in from the +X side of oil inlet 104 passes through flow passage 120, flow passage 121, and flow passage 122 and reaches groove portion 123. FIG. 4 is a perspective view of frame 101 in FIG. 1, as viewed from the -Y side. The radially inner end of flow passage 122 is located in groove portion 123, which is recessed radially outward from inner circumferential surface 101a of frame 101. FIG. 5 is a perspective view of stator core 140 in FIG. 1. Stator core 140 has an outer circumferential surface 146. Inner circumferential surface 101a of frame 101 contacts outer circumferential surface 146 of stator core 140. Because groove portion 123 is recessed radially outward from inner circumferential surface 101a, a gap exists between groove portion 123 and outer circumferential surface 146 of stator core 140, and oil is supplied to this gap from flow passage 122.

[0030] 3 and 4, the groove 123 extends over the entire circumferential direction. Therefore, oil that flows into the gap between the groove 123 and the outer peripheral surface 146 flows over the entire circumferential direction of the stator core 140. The radially outer end of the flow passage 141 shown in FIG. 5 faces the groove 123. Therefore, the oil that flows through the gap between the groove 123 and the outer peripheral surface 146 flows into the flow passage 141. In this embodiment, the axial position of the radially outer end of the flow passage 141 coincides with the axial position of the radially inner end of the flow passage 122.

[0031] The stator core 140 is formed by stacking a plurality of electromagnetic steel sheets in the axial direction. Of the plurality of electromagnetic steel sheets that make up the stator core 140, electromagnetic steel sheet 140b is an electromagnetic steel sheet that has a radially outer end of the flow passage 141. Of the plurality of electromagnetic steel sheets that make up the stator core 140, electromagnetic steel sheet 140a and electromagnetic steel sheet 140c are electromagnetic steel sheets that do not have a radially outer end of the flow passage 141. Electromagnetic steel sheet 140a is located on the other axial side of electromagnetic steel sheet 140b. Electromagnetic steel sheet 140c is located on one axial side of electromagnetic steel sheet 140b. The stator core 140 is formed by stacking a plurality of electromagnetic steel sheets 140a, a plurality of electromagnetic steel sheets 140b, and a plurality of electromagnetic steel sheets 140c in the axial direction.

[0032] FIG. 6 is a perspective cross-sectional view of the stator core 140 of FIG. 5 cut along a plane that passes through the center of the flow passage 141 and is perpendicular to the Z-axis. In FIG. 6, a plane perpendicular to the axial direction of the electromagnetic steel sheet 140b is visible. FIG. 7 is a perspective cross-sectional view of the stator core 140 of FIG. 5 cut along a plane that passes through the center of the flow passage 141 and is perpendicular to the X-axis. The electromagnetic steel sheet 140b has flow passages 141 that extend radially inward from the outer circumferential surface of the stator core 140, and slots 144 that accommodate the coils 150. The electromagnetic steel sheet 140b has bridge portions 143 between the flow passages 141 and the slots 144.

[0033] In order to supply oil from flow passage 141 to slot 144, it is conceivable to connect flow passage 141 and slot 144 in electromagnetic steel sheet 140b. However, doing so would result in electromagnetic steel sheet 140b being divided in the circumferential direction. Therefore, in this embodiment, electromagnetic steel sheet 140b has a transition portion 143 that connects electromagnetic steel sheet 140b in the circumferential direction radially outward from the radially outer end of slot 144. By providing this transition portion 143, electromagnetic steel sheet 140b is not divided and is composed of a single electromagnetic steel sheet.

[0034] By providing the transition portion 143, oil is not supplied directly from the flow path 141 to the slot 144. Therefore, in this embodiment, the electromagnetic steel sheets 140a and 140c form a flow path through which the oil in the flow path 141 is supplied to the slot 144. The electromagnetic steel sheets 140a and 140c have flow paths 142 and 145 as this flow path.

[0035] The shape of the electromagnetic steel sheet 140c is the same as that of the electromagnetic steel sheet 140a. As shown in FIG. 5, the electromagnetic steel sheet 140a has flow passages 142, flow passages 145, and slots 144. The flow passages 142, 145, and slots 144 penetrate in the axial direction. In FIG. 3, the flow passages 142 of the electromagnetic steel sheet 140c can be seen on one axial side of the flow passages 141. The flow passages 142 overlap with the flow passages 141 in the axial direction. The radially outer end of the flow passages 142 is located radially outward of the radially outer end of the transition portion 143. Therefore, oil in the flow passages 141 of the electromagnetic steel sheet 140b can flow into the flow passages 142. Because the flow passages 142 are connected to the slots 144 by the flow passages 145, the oil in the flow passages 141 is supplied to the slots 144, and the housed coil 151 in the slots 144 can be directly cooled by the oil.

[0036] The circumferential width of the flow passage 145 is narrower than the circumferential width of the slot 144. This makes it possible to prevent the housed coil 151 in the slot 144 from being displaced radially outward from the slot 144.

[0037] Flow paths 142 in electromagnetic steel plate 140a open to the other axial end of stator coil 140. The oil in flow paths 142 flows out of stator coil 140 from the other axial end of stator coil 140 and cools coil ends 152. Flow paths 142 in electromagnetic steel plate 140c open to one axial end of stator coil 140. The oil in flow paths 142 flows out of stator coil 140 from the one axial end of stator coil 140 and cools coil ends 153.

[0038] 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]

[0039] 100...motor, 101...frame, 106...rotor, 110...shaft, 107...stator, 140...stator core, 150...coil

Claims

1. a rotor having a shaft extending along a central axis; a stator disposed radially outside the rotor via an air gap; a frame that houses the stator; Equipped with the stator includes a stator core and a coil that excites the stator core, the frame has, on an inner peripheral surface facing the stator, a groove portion recessed radially outward from a position where the frame contacts an outer peripheral surface of the stator core, the stator core has a plurality of slots that accommodate at least a portion of the coil, and a first flow path that is a flow path of a refrigerant liquid that extends radially inward from a surface facing the groove portion and continues to a portion of the coil that is accommodated in the plurality of slots, The coil has a coil end exposed from an axial end of the stator core, the stator core has a second flow path that is a flow path for refrigerant liquid extending axially from the first flow path to the coil end, The stator core is formed by laminating a plurality of electromagnetic steel plates in the axial direction, the plurality of electromagnetic steel sheets include a first electromagnetic steel sheet having a radially outer end of the first flow passage and a second electromagnetic steel sheet not having a radially outer end of the first flow passage, the first electromagnetic steel sheets have bridge portions that connect the first electromagnetic steel sheets in the circumferential direction radially outward of the radially outer ends of the slots, the second electromagnetic steel sheet has the second flow passage continuing from a radially inner end of the first flow passage to a radially outer end of the slot, the second electromagnetic steel sheet has a third flow passage connecting a radially inner end of the second flow passage and a radially outer end of the slot, The circumferential width of the third flow path is narrower than the circumferential width of the slot. Rotating electric motor.

2. The groove portion extends over the entire circumference in the circumferential direction. The rotating electric machine according to claim 1 .

3. The first flow path is arranged for each of the plurality of slots. The rotating electric machine according to claim 1 or 2.

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