Rotating electric machine

Abstract

The objective is to provide a rotating electric machine with improved cooling of the coil ends. [Solution] The rotating electric machine has a stator having a stator core and coil ends protruding from the axial ends of the stator core; a rotor positioned radially inward of the stator and facing the stator via an air gap; at least one refrigerant discharge pipe positioned vertically above the stator; and a dripping section for dripping the refrigerant discharged from the refrigerant discharge pipe onto the coil ends. The dripping section is provided on both sides of the radial direction perpendicular to the vertical direction passing through the central axis, and each side of the dripping section overlaps with the coil end in a plan view, and is positioned radially greater than or equal to the inner radius and within the outer radius of the coil end.

Description

Technical Field

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

Background Art

[0002] Conventionally, a structure for cooling a rotating electrical machine has been known. Patent Document 1 discloses a cooling structure for a rotating electrical machine that supplies cooling oil to coil ends at both ends of a stator core by injecting cooling oil from an oil passage pipe provided at the upper part of the stator core of the rotating electrical machine and extending in the axial direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, the cooling oil injected from the oil passage pipe is directly injected toward the coil end. Therefore, even if the injection momentum is increased, there is a problem that it is difficult for the cooling oil to reach the outside in the left-right direction beyond the contact point where the straight line orthogonal to the oil passage pipe touches the outer periphery of the coil end. Also, increasing the injection momentum requires increasing the output of the pump that sends out the cooling oil, which causes problems such as an increase in the cost of the pump. Furthermore, it has been difficult to accurately supply the cooling oil to the target position of the coil end. For this reason, conventionally, there has been room for improvement in cooling the coil end.

[0005] The present invention has been made in view of the above points, and an object thereof is to provide a rotating electrical machine with improved cooling of the coil end.

Means for Solving the Problems

[0006] A rotating electric machine according to one aspect of the present invention comprises a stator having a stator core and coil ends protruding from the axial ends of the stator core; a rotor arranged radially inward of the stator and facing the stator via an air gap; at least one refrigerant discharge pipe arranged vertically above the stator; and a dripping section for dripping the refrigerant discharged from the refrigerant discharge pipe onto the coil ends, wherein the dripping section is provided on both sides in the radial direction perpendicular to the vertical direction passing through the central axis, and each side of the dripping section overlaps with the coil ends in a plan view, and is located radially greater than or equal to the inner radius and within the outer radius of the coil ends. [Effects of the Invention]

[0007] According to one aspect of the present invention, a rotating electric machine with improved cooling of the coil ends can be provided. [Brief explanation of the drawing]

[0008] [Figure 1] This is a side cross-sectional view of a motor 10 according to Embodiment 1 of the present invention. [Figure 2] This is a plan view showing the top of the stator 200 with the motor frame 100 and bracket 900 removed from the motor 10. [Figure 3] This is a front view of bracket 900 as seen from the -Y side. [Figure 4] This is a schematic diagram illustrating the concept of cooling the first coil end 230 of the motor 10. [Modes for carrying out the invention]

[0009] The following description of a rotating electric machine according to an embodiment of the present invention will be made with reference to the drawings. Note that in the following drawings, the scale and number of components in each structure may differ from the actual structure in order to make the components easier to understand.

[0010] <Embodiment 1> Figure 1 is a side cross-sectional view of a motor 10 according to Embodiment 1 of the present invention. The motor 10 rotates with a shaft 400 extending along the central axis J as its axis of rotation. The motor 10 is an example of a rotating electric machine. Figure 1 is a side cross-sectional view of the motor 10, shown when it is cut by a plane that passes through the central axis J and is parallel to the direction in which the central axis J extends and to the vertical direction.

[0011] Furthermore, in the drawings, the XYZ coordinate system is shown as a three-dimensional Cartesian coordinate system where appropriate. In the XYZ coordinate system, the Y-axis direction is parallel to the axis direction of the central axis J shown in Figure 1. The Z-axis direction is the vertical direction in Figure 1, which is the radial direction with respect to the central axis J. The X-axis direction is perpendicular to both the Y-axis and Z-axis directions. In the X-axis, Y-axis, and Z-axis directions, the side indicated by the arrow in the drawing is the + side, and the opposite side is the - side.

[0012] Furthermore, in the following explanation, the positive side in the Y-axis direction (+Y side) will be referred to as "one side," and the negative side in the Y-axis direction (-Y side) will be referred to as "the other side." Note that "one side" and "the other side" are merely names used for explanatory purposes and do not limit the actual positional relationship or direction. Also, unless otherwise specified, the direction parallel to the central axis J (Y-axis direction) will be simply referred to as the "axis direction," 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, that is, around the axis of the central axis J, will be simply referred to as the "circumferential direction." In the radial direction, the side approaching the central axis J will be referred to as the "inside radial direction," and the side moving away from the central axis J will be referred to as the "outside radial direction." In the circumferential direction, the clockwise side when looking from the -Y side to the +Y side will be referred to as the "one side circumferential," and the counterclockwise side will be referred to as the "other side circumferential."

[0013] In this specification, "extending in the axial direction" includes not only cases where the material extends strictly in the axial direction, but also cases where the material extends in a direction inclined to the axial direction by an angle of less than 45°. Furthermore, in this specification, "extending radially" includes not only cases where the material extends strictly radially, i.e., perpendicular to the axial direction, but also cases where the material extends in a direction inclined to the radial direction by an angle of less than 45°. Furthermore, "parallel" includes not only cases where the material is strictly parallel, but also cases where the angle between the material and the material is inclined to each other by an angle of less than 45°. Furthermore, "spreading in a direction perpendicular to the axial direction" includes not only cases where the material spreads in a direction perpendicular to the axial direction, but also cases where the material spreads in a direction inclined to the direction perpendicular to the axial direction by an angle of less than 45°.

[0014] The motor 10 includes a stator 200, a rotor 300 positioned opposite the stator 200 radially inward with an air gap in between, and a shaft 400 fixed radially inward of the rotor 300 and extending along the central axis J. The stator 200 includes a stator core 210, a coil end 230 protruding axially in one direction at one axial end of the stator core 210, and a coil end 220 protruding axially in the other direction at the other axial end of the stator core 210.

[0015] Furthermore, the motor 10 has a motor frame 100 that covers the stator 200 from the radially outer side. The motor frame 100 houses the stator 200, rotor 300, and shaft 400 by covering the stator 200 from the radially outer side. The motor frame 100 has a substantially cylindrical shape with openings on both axial sides. The motor 10 has a bracket 900 provided at the opening on one axial side of the motor frame 100, and a bracket 800 provided at the opening on the other axial side of the motor frame 100.

[0016] Furthermore, the motor 10 has a refrigerant discharge pipe 510 (see Figure 2) and a refrigerant discharge pipe 520 that discharge refrigerant toward the stator 200, and a refrigerant tank 600 that temporarily stores refrigerant and flows it vertically downward. The refrigerant discharge pipes 510, 520, and 600 are located within the stator 200, on the vertically upper side of the stator 200. The refrigerant is, for example, cooling oil. The refrigerant supplied to the stator 200 cools the stator 200. In this embodiment, the Z direction is the vertical direction, and the refrigerant supplied to the stator 200 from the refrigerant discharge pipes 510, 520, and 600 flows to the +Z side and is stored in an oil pan (not shown) located vertically downward within the motor frame 100. The refrigerant stored in the oil pan is drawn up by the pump 700, cooled by the oil cooler (not shown), and then circulated and supplied to the refrigerant discharge pipes 510 and 520. The material of the refrigerant discharge pipes 510 and 520 is, for example, iron or resin.

[0017] Furthermore, as will be described in detail later with reference to Figure 3, the bracket 900 has protrusions 920 (see Figure 3) and 930 on the side facing the motor frame 100, which protrude in the other axial direction. The protrusion 920 has a dripping portion 922 (see Figure 3) for dripping refrigerant, and the protrusion 930 has a dripping portion 932 for dripping refrigerant. The dripping portions 922 and 932 overlap with the coil end 230 in a plan view.

[0018] Figure 2 is a plan view showing the motor 10 with the motor frame 100 and bracket 900 removed, revealing the upper part of the stator 200. The refrigerant discharge pipe 510 is positioned offset to one side in the circumferential direction from directly above the central axis J, and the refrigerant discharge pipe 520 is positioned offset to the other side in the circumferential direction from directly above the central axis J. The refrigerant discharge pipes 510 and 520 extend parallel to each other in the axial direction. In this embodiment, two discharge pipes, the refrigerant discharge pipe 510 and the refrigerant discharge pipe 520, are provided, but the present invention is not limited to this, and at least one refrigerant discharge pipe is sufficient.

[0019] The refrigerant discharge pipe 510 has a discharge port 510a for discharging the refrigerant supplied to the refrigerant discharge pipe 510. The refrigerant discharge pipe 520 has a discharge port 520a for discharging the refrigerant supplied to the refrigerant discharge pipe 520. In addition to the discharge ports 510a and 520a, the refrigerant discharge pipe 510 and the refrigerant discharge pipe 520 have discharge ports (not shown) for supplying refrigerant to the refrigerant tank 600 and discharge ports (not shown) for discharging refrigerant to various parts of the stator 200.

[0020] The refrigerant tank 600 has a recess for temporarily storing the refrigerant discharged by the refrigerant discharge pipes 510 and 520. This recess has a through-hole in the bottom surface, and the refrigerant can flow downward. The refrigerant flowing out from the through-hole in the bottom surface of the refrigerant tank 600 cools the portion directly above the shaft 400 in the coil end 230 and the like.

[0021] FIG. 3 is a front view of the bracket 900 as viewed from the -Y side. The bracket 900 covers the coil end 230. The bracket 900 has a facing surface 910 facing the stator 200 on the side facing the motor frame 100. Further, the bracket 900 has convex portions 920 and 930 protruding axially toward the other side from the facing surface 910. That is, the convex portions 920 and 930 are integrally formed with the bracket 900.

[0022] The convex portion 920 has a guiding portion 921 for guiding the refrigerant flowing on the upper surface of the convex portion 920 to the dripping portion 922, a dripping portion 922 for dripping the refrigerant flowing after being guided by the guiding portion 921, and a stopping portion 923 for stopping the flow of the refrigerant to the -X side from the dripping portion 922.

[0023] The dripping portion 922 has a corner at the position where it contacts the guide portion 921 and the stopping portion 923. The presence of a corner in the dripping portion 922 facilitates the dripping of the refrigerant. At least the dripping portion 922 of the protrusion 920 is located on the axial side of one axial end of the coil end 230. Furthermore, the position of the dripping portion 922 in the X direction is on the +X side of the -X side of the coil end 230 and on the -X side of the +X side, and is located near the -X side of the coil end 230. In addition, the dripping portion 922 may overlap with the coil end 230 in a plan view and be located radially within the inner radius r (see Figure 4) and outer radius R (see Figure 4) of the coil end 230. The inner radius r refers to the length from the central axis J in a straight line extending in a direction perpendicular to the vertical direction within the radial direction to the radially inner end of the coil end 230, and also refers to the length from the central axis J in a straight line extending in a direction perpendicular to the vertical direction within the radial direction to the radially outer end of the coil end 230. The dripping part 922 drips refrigerant onto the coil end 230 in a direction perpendicular to the vertical direction passing through the central axis within the radial direction, on the -X side.

[0024] The upper surface of the guide section 921 receives the refrigerant discharged from the discharge port 510a. The guide section 921 has a slope such that the dripping section 922 side is lower than the position where it receives the refrigerant discharged from the discharge port 510a, and the refrigerant travels along this slope and reaches the dripping section 922 by its own weight. Since the dripping section 922 is lower than the guide section 921 and the retaining section 923, the refrigerant remains there, and this refrigerant overflows from the other axial end of the dripping section 922 and drips towards the coil end 230. The guide section 921 has a slope such that the dripping section 922 side is lower than the position where it receives the refrigerant discharged from the discharge port 510a, which facilitates the flow of the refrigerant. To prevent the refrigerant from dripping anywhere other than the dripping section 922, it is desirable that the guide section 921 and the retaining section 923 have a slope such that one axial side is higher than the other axial side.

[0025] The protrusion 930 has a guide portion 931 that guides the refrigerant flowing on the upper surface of the protrusion 930 to the dripping portion 932, a dripping portion 932 that drips the refrigerant that has flowed guided by the guide portion 931, and a stopping portion 933 that stops the flow of refrigerant toward the +X side from the dripping portion 932.

[0026] The dripping portion 932 has a corner at the position where it contacts the guide portion 931 and the stopping portion 933. The presence of a corner in the dripping portion 932 facilitates the dripping of refrigerant. At least the dripping portion 932 of the protrusion 930 is located on the axial side of one axial end of the coil end 230. Furthermore, the position of the dripping portion 932 in the X direction is on the -X side of the +X side end of the coil end 230, and is located near the +X side end of the coil end 230. In addition, the dripping portion 932 may overlap with the coil end 230 in a plan view and be located radially at or above the inner radius r and within the outer radius R of the coil end 230. The dripping portion 932 drips refrigerant onto the coil end 230 in the radial direction perpendicular to the vertical direction passing through the central axis, on the +X side. In this embodiment, the dropping parts are provided as dropping parts 922 and 932 on both sides in the radial direction perpendicular to the vertical direction passing through the central axis, with each side of the dropping parts overlapping with the coil end 230 in a plan view, and positioned in the radial direction greater than or equal to the inner radius and within the outer radius of the coil end 230.

[0027] The upper surface of the guide section 931 receives the refrigerant discharged from the discharge port 520a. The guide section 931 has a slope such that the dripping section 932 side is lower than the position where the refrigerant discharged from the discharge port 520a is received, and the refrigerant travels along this slope and reaches the dripping section 932 by its own weight. Since the dripping section 932 is lower than the guide section 931 and the retaining section 933, the refrigerant remains there, and this refrigerant overflows from the other axial end of the dripping section 932 and drips toward the coil end 230. The guide section 931 has a slope such that the dripping section 932 side is lower than the position where the refrigerant discharged from the discharge port 520a is received, which facilitates the flow of the refrigerant. To prevent the refrigerant from dripping anywhere other than the dripping section 932, it is desirable that the guide section 931 and the retaining section 933 have a slope such that one axial side is higher than the other axial side.

[0028] Figure 4 is a schematic diagram illustrating the concept of cooling the first coil end 230 of the motor 10. In Figure 4, the refrigerant discharge pipes 510 and 520 are collectively shown as the refrigerant discharge pipe 500, and the refrigerant discharge pipe 500 is shown having discharge ports 510a and 520a. The dripping sections 922 and 932 are located radially within the inner radius and outer radius of the coil end 230.

[0029] The refrigerant flowing axially through the refrigerant discharge pipe 500 is discharged from discharge ports 510a and 520a. The refrigerant discharged from discharge port 510a is supplied to the protrusion 920 and dripped onto the coil end 230 from the dripping portion 922 of the protrusion 920. The refrigerant discharged from discharge port 520a is supplied to the protrusion 930 and dripped onto the coil end 230 from the dripping portion 932 of the protrusion 930.

[0030] The position from which the refrigerant is dripped from the dripping parts 922 and 932 can be set to any position in the X direction of the coil end 230 by adjusting the position of the dripping parts 922 and 932. Therefore, it is possible to supply refrigerant to positions that were previously inaccessible to refrigerant.

[0031] Furthermore, the refrigerant discharged from the outlets 510a and 520a only needs to reach the guide portion 921 of the protrusion 920 and the guide portion 931 of the protrusion 930, eliminating the need for precise targeting accuracy and the need to increase the force of the injection, thus allowing the refrigerant to be supplied to the desired position on the coil end 230.

[0032] In this embodiment, the protrusions 920 and 930 are provided only on the bracket 900, but similar protrusions may also be provided on the bracket 800 to supply refrigerant to the coil end 220.

[0033] According to this embodiment, since the bracket 900 is provided with protrusions 920 and 930, the protrusions 920 and 930 can also function as ribs to increase the rigidity of the bracket 900.

[0034] Furthermore, in this embodiment, since the bracket 900 is provided with protrusions 920 and 930, the cost, manufacturing process, and number of parts can be reduced compared to the case where a member for dripping refrigerant toward the coil end is newly provided by another member.

[0035] According to this embodiment, refrigerant can be supplied evenly and uniformly to the entire coil end. This reduces the likelihood of coil deterioration due to high temperatures, thereby improving the reliability of the motor.

[0036] The present invention is not limited to the embodiments described above, and various improvements and design modifications may be made without departing from the spirit of the invention. For example, the motor 10 may be configured without the refrigerant tank 600.

[0037] The present invention is not limited to the embodiments described above, and various improvements and design modifications may be made without departing from the spirit of the invention. In addition, the embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the above description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0038] 10…motor 100...Motor frame 200...Stata 300... Rotor 400...shaft 510, 520...refrigerant discharge pipe 900...bracket

Claims

1. A stator having a stator core and coil ends protruding from the axial ends of the stator core, A rotor is positioned radially inward of the stator and faces the stator via an air gap, At least one refrigerant discharge pipe positioned vertically above the stator, A dripping part that drips the refrigerant discharged from the refrigerant discharge pipe onto the coil end, It has, The aforementioned dropping parts are provided on both sides of the radial direction perpendicular to the vertical direction passing through the central axis, Each of the two sides of the dropper portion overlaps with the coil end in a plan view, and in the radial direction, is located greater than or equal to the inner radius and within the outer radius of the coil end. A rotating electric machine characterized by the following features.

2. The system further includes a guide section that guides the refrigerant discharged from the refrigerant discharge pipe to the dripping section. The guide portion has an incline such that the dripping portion is lower than the position where the refrigerant discharged from the refrigerant discharge pipe is received. The rotating electric machine according to feature 1.

3. The aforementioned dropping part has a corner. The rotating electric machine according to feature 1.

4. The device further includes a bracket that covers the coil end, The dropping part is integrally formed with the bracket. A rotating electric machine according to any one of claims 1 to 3.

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