Rotating electric machines

Abstract

The present invention provides a rotating electric machine (100), which comprises: a winding (10); a stator core (20) having a slot for setting the winding (10); a cover portion covering the stator core (20); and a transition portion (50), which is a space formed between the cover portion and the stator core (20), in which the axial end of the winding (10) is exposed in the transition portion (50), and a filling member is arranged between the radial side surface of the winding (10) and the radial inner side surface of the cover portion.

Description

Technical Field

[0001] The present invention relates to rotating electrical machines. Background Art

[0002] In hybrid vehicles and electric vehicles, motors are sometimes cooled by immersing the motor windings in oil using a refrigerant to improve cooling performance compared to conventional water cooling (using a water jacket) or oil drip cooling (Japanese Patent No. 2716286). Summary of the Invention

[0003] The aforementioned invention forms a transition section (space) between the stator core and the housing. In this transition section, refrigerant can flow into the excess space. This prevents the refrigerant from entering the minute gaps between the windings, reducing cooling performance. Consequently, there is the issue of high temperatures in the transition section.

[0004] An object of an aspect of the present invention is to provide a rotating electrical machine having a structure capable of reliably allowing a refrigerant to enter a minute gap between windings.

[0005] The rotating electrical machine of the first embodiment of the present invention comprises: a winding; a stator core having a slot for setting the winding; a cover portion covering the stator core; a transition portion, which is a space formed between the cover portion and the stator core, wherein, in the transition portion, the axial end of the winding is exposed, and a filling member is arranged between the radial side surface of the winding and the radial inner side surface of the cover portion.

[0006] According to the first aspect, a filling member is disposed between the radial side surface of the winding and the radial inner surface of the cover. That is, the filling member eliminates the gap in the transition portion. This allows the refrigerant to reliably enter the gaps between the wires forming the winding.

[0007] The rotating electrical machine according to the second aspect may include a shield member between the winding and the filling member.

[0008] Depending on the filling member provided between the winding and the cover, the filling member may penetrate into the gaps between the windings and fill the gaps, thereby preventing the refrigerant from entering the gaps between the windings.

[0009] In contrast, according to the second aspect, a shielding member is provided between the winding and the filling member, thereby avoiding the above-mentioned problem.

[0010] In a third aspect, the filling member may be a semi-solid resin.

[0011] According to the third aspect, the filling member is a semi-solid resin. This allows the filling member to be effectively provided in accordance with the shape of the gap between the winding and the cover.

[0012] In the fourth aspect, the filling member may contain a foaming agent.

[0013] According to the fourth aspect, the filling member contains a foaming agent. Thus, when the filling member is placed in the gap of the transition portion, the foaming agent foams, thereby completely filling the gap of the transition portion.

[0014] The rotating electric machine of the fifth embodiment of the present invention comprises: a winding; a stator core having a slot for setting the winding; a cover portion covering the stator core; and a transition portion formed by the cover portion and the stator core, wherein the gap between the radial side surface of the winding and the radial inner side surface of the cover portion is smaller than the gap between the wires constituting the winding.

[0015] According to the fifth embodiment, the gap between the radial side surface of the winding and the radial inner surface of the cover is smaller than the gap between the wires forming the winding. This allows the refrigerant to flow easily between the wires forming the winding within the cover, thereby improving the refrigerant's cooling efficiency within the winding.

[0016] In the sixth aspect, the radial side surface of the winding may be in contact with the radial inner side surface of the cover portion.

[0017] According to the sixth aspect, the radial side surface of the winding is in contact with the radial inner side surface of the cover. Thus, the shape of the cover eliminates gaps in the transition portion, thereby reliably allowing the refrigerant to enter the gaps between the wires constituting the winding.

[0018] In the seventh aspect, the cover portion may have a protrusion protruding toward the winding.

[0019] According to the seventh aspect, the cover has a protrusion that protrudes toward the winding. Thus, in the transition portion, only the protrusion can be brought into contact with the winding. Thus, for example, by simply changing the shape of the cover in an existing product, the effects of the present invention can be achieved.

[0020] The rotating electrical machine of the eighth embodiment of the present invention comprises: a winding; a stator core having slots for setting the winding; a cover portion covering the stator core; a transition portion formed by the cover portion and the stator core, and the duty factor of the portion of the winding located in the transition portion is lower than the duty factor of the portion of the winding located in the slots.

[0021] According to the eighth aspect, the space factor of the winding at the transition portion is lower than the space factor of the winding at the slot portion. In the winding at the transition portion, the gaps in the winding are widened, making it easier for the refrigerant to enter the winding.

[0022] According to the aspects of the present invention, it is possible to provide a rotating electrical machine having a structure capable of reliably allowing a refrigerant to enter fine gaps between windings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a cross-sectional view showing a rotating electrical machine according to one embodiment of the present invention.

[0024] Figure 2 This is a schematic diagram showing a winding according to one embodiment of the present invention.

[0025] Figure 3 yes Figure 2 An enlarged cross-sectional view of a straight line in the winding is shown.

[0026] Figure 4 It is an enlarged cross-sectional view showing a refrigerant flow path at a transition portion according to the embodiment.

[0027] Figure 5 is Figure 4 A modified example in which the cover portion is reduced in size.

[0028] Figure 6 is Figure 4 A modified example in which a protrusion is provided on the cover.

[0029] Figure 7 It means in Figure 4 An enlarged cross-sectional view of a refrigerant flow path when no filling member is provided. DETAILED DESCRIPTION

[0030] Hereinafter, a rotating electrical machine 100 according to an embodiment of the present invention will be described with reference to the drawings.

[0031] like Figure 1 、 Figure 2 As shown, the rotating electrical machine 100 includes a winding 10 , a stator core 20 , a first cover portion 30 (cover portion), a second cover portion 40 (cover portion), a transition portion 50 , and a rotor R.

[0032] Rotating electric machine 100 is, for example, a motor used in a hybrid vehicle or an electric vehicle.

[0033] The rotating electrical machine 100 generates magnetic force by energizing the windings 10 provided on the stator core 20, thereby rotating the rotor R. The rotor R is the rotating shaft of the rotating electrical machine 100. The rotor R has magnetism and rotates under the magnetic force generated by energizing the windings 10.

[0034] The winding 10 is formed by forming the conductive wire L into a bundle. Figure 2 、 Figure 3 As shown, the winding 10 includes a connecting line 11 and a straight line 12 .

[0035] The overlapped wires 11 are located at both axial ends of the stator core 20. The overlapped wires 11 are portions where the windings 10 protrude from slots 20S (described later) of the stator core 20.

[0036] The straight line 12 is provided in the slot 20S of the stator core 20. The straight line 12 is provided in a plurality of slots 20S spaced apart circumferentially of the stator core 20. In other words, a plurality of straight lines 12 are provided at intervals circumferentially of the stator core 20. Furthermore, as described above, the jumper wire 11 is the portion of the winding 10 that protrudes from the slot 20S of the stator core 20. Therefore, a plurality of jumpers 11 are also provided at intervals circumferentially of the stator core 20. Furthermore, the outer diameter of the wire L can preferably be set to 0.1 mm to 3 mm.

[0037] The stator core 20 is a cylindrical member. The stator core 20 houses the rotor R within the cylindrical interior. Electromagnetic steel sheets are preferably used for the stator core 20. Slots 20S are provided in an annular pattern at intervals on the cylindrical inner circumference of the stator core 20.

[0038] The slots 20S are arranged in a straight line along the length direction of the stator core 20. Figure 3 As shown, the slot 20S is formed into a trapezoidal shape in a cross section perpendicular to the longitudinal direction of the stator core 20. The straight line 12 of the winding 10 is provided inside the slot 20S.

[0039] The first cover portion 30 covers one axial end portion of the stator core 20. This prevents the overlap wires 11 of the winding 10 protruding from one end portion of the stator core 20 from being exposed to the outside and forms a transition portion 50 (described later) for circulating the refrigerant C into the stator core 20.

[0040] The second cover portion 40 covers the other end of the stator core 20 , thereby preventing the overlapping wires 11 of the winding 10 protruding from the other end of the stator core 20 from being exposed to the outside and forming a transition portion 50 for circulating the refrigerant C into the stator core 20 .

[0041] The transition portion 50 is a space formed by the first cover portion 30 or the second cover portion 40 and the stator core 20. Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 As shown, the jumper wires 11 of the winding 10 are located inside the transition portion 50. The refrigerant C for cooling the winding 10 circulates through the transition portion 50.

[0042] The refrigerant C cools the winding 10, which generates heat due to the power supply. In this embodiment, a conventional ATF (automatic transmission fluid) is preferably used as the refrigerant C. The refrigerant C cools the winding 10 by flowing through the gaps between the wires L of the jumper wires 11 and the straight wires 12 of the winding 10 in the transition portion 50 and the slot 20S.

[0043] like Figure 1 As shown, refrigerant C circulates within the rotating electrical machine 100. Specifically, refrigerant C first enters the transition portion 50 on the first cover portion 30 side from the inlet IN provided in the first cover portion 30. Refrigerant C first fills the transition portion 50 on the first cover portion 30 side. This cools the overlapped wires 11 on the first cover portion 30 side.

[0044] Next, the refrigerant C moves from the transition portion 50 on the first cover portion 30 side to the slots 20S of the stator core 20. This cools the straight lines 12. The refrigerant C that has passed through the slots 20S moves to the transition portion 50 on the second cover portion 40 side. The transition portion 50 on the second cover portion 40 side is then filled with the refrigerant C. This cools the overlapping lines 11 on the second cover portion 40 side.

[0045] When the transition portion 50 on the second cover portion 40 side is filled with the refrigerant C, the refrigerant C is discharged from the outlet OUT provided in the second cover portion 40 .

[0046] The refrigerant C discharged from the outlet OUT is cooled by an oil cooler (not shown) or the like, and then enters the transition portion 50 on the first cover portion 30 side from the inlet IN again by a pump (not shown) or the like.

[0047] In the circulation of the refrigerant C, when the refrigerant C cools the winding 10, the refrigerant C comes into direct contact with the wire L constituting the winding 10. As a result, the heat of the wire L is transferred to the refrigerant C. Figure 7 As shown, if the refrigerant C does not move toward the slot 20S through the inside of the jumper wire 11 , the conductive wire L inside the jumper wire 11 does not come into contact with the refrigerant C, and sufficient cooling performance cannot be obtained.

[0048] If the intervals between the wires L of the winding 10 are narrow, the refrigerant C cannot fully enter the wires L due to its viscosity. Furthermore, if a path (gap) exists within the transition portion 50 through which the refrigerant C can move toward the slots 20S without passing through the jumper wires 11, the refrigerant C will naturally move toward the slots 20S through this path.

[0049] The following describes a structure for reliably contacting the refrigerant C with the overlap line 11 by taking the shape of the first cover portion 30 as an example. Note that the following description of the shape of the first cover portion 30 and the transition portion 50 is also applicable to the shape of the second cover portion 40 .

[0050] exist Figure 4 In the illustrated transition portion 50, the portion of the winding 10 located at the axial end of the stator core 20 is exposed, and a filling member F is disposed between the radial side surface of the winding 10 and the radial inner surface of the first cover portion 30. Specifically, the filling member F eliminates the gap between the radial side surface of the winding 10 and the radial inner surface of the first cover portion 30. As a result, the refrigerant C is prevented from moving toward the slot 20S without passing through the overlap wire 11.

[0051] The filling member F is preferably made of a semi-solid resin, such as an epoxy-based thermosetting resin. Furthermore, the filling member F may preferably contain a foaming agent, such as an epoxy-based foaming resin. This allows the filling member F to completely fill the gaps in the transition portion 50, ensuring that the refrigerant C can reliably pass through the interior of the lap joint 11.

[0052] When filling member F is provided in transition portion 50, depending on the viscosity of filling member F, filling member F may penetrate into the gaps between wires L of jumper wire 11. This fills the gaps between wires L to which refrigerant C is supplied, preventing refrigerant C from entering.

[0053] Therefore, if Figure 4 As shown, a shielding member 11W may be preferably provided between the bonding wire 11 and the filling member F. This prevents the filling member F from penetrating into the gaps between the conductors L of the bonding wire 11. For example, a known wrap film is preferably used as the shielding member 11W.

[0054] like Figure 4 As shown, the shielding member 11W may preferably be provided on at least both side surfaces of the overlapped wire 11 in the radial direction of the stator core 20. The shielding member 11W may more preferably be provided on the surface facing the stator core 20 in the axial direction of the stator core 20. Furthermore, in order to ensure a flow path for the refrigerant C to flow into the overlapped wire 11, the shielding member 11W is preferably not provided on the surface facing the first cover portion 30 in the axial direction of the stator core 20.

[0055] In addition, if Figure 5 As shown, by reducing the first cover portion 30, the gap between the radial side surface of the jumper wire 11 in the winding 10 and the radial inner side surface of the first cover portion 30 can be made smaller than the gap between the wires L constituting the winding 10. Alternatively, the radial side surface of the jumper wire 11 can be in contact with the radial inner side surface of the first cover portion 30. Thus, if the gap larger than the gap between the wires L of the jumper wire 11 is eliminated within the transition portion 50, the refrigerant C will move toward the slot 20S through the interior of the jumper wire 11.

[0056] In addition, if Figure 6As shown, the first cover portion 30 may be provided with a protrusion 30P, which is in contact with the lap line 11. With such a shape, the refrigerant C can also move toward the slot 20S through the inside of the lap line 11.

[0057] In addition, the gaps between the conductors L of the jumper wire 11 can be increased to allow the refrigerant C to easily pass through the gaps between the conductors L of the jumper wire 11. That is, the duty cycle of the jumper wire 11 can be made larger than the duty cycle of the straight line 12 located in the slot 20S. Here, the duty cycle refers to the density of the conductors L per unit area in the cross section of the winding 10. In this embodiment, with respect to the jumper wire 11, it refers to a cross section parallel to the axial direction of the stator core 20. Moreover, with respect to the straight line 12, it refers to a cross section orthogonal to the axial direction of the stator core 20. Regardless of the above, Figure 4 、 Figure 5 、 Figure 6 The shapes of the first covers shown are applicable to any of the cases.

[0058] As described above, according to the rotating electrical machine 100 of this embodiment, the filling member F is disposed between the radial side surfaces of the winding 10 and the radial inner surfaces of the first cover portion 30 and the second cover portion 40. Specifically, the filling member F eliminates the gaps in the transition portion 50. This allows the refrigerant C to reliably enter the gaps between the conductive wires L that constitute the winding 10.

[0059] Depending on the filling member F provided between the winding 10 and the first and second cover parts 30 and 40 , the filling member F may penetrate into and fill the gaps in the winding 10 , thereby preventing the refrigerant C from entering the gaps in the winding 10 .

[0060] In contrast, a shield member 11W is provided between the winding 10 and the filling member F. This can avoid the above-mentioned problem.

[0061] Furthermore, the filling member F is a semi-solid resin. Thus, the filling member F can be effectively provided in accordance with the shape of the gap between the winding 10 and the first and second cover portions 30 and 40 .

[0062] Furthermore, the filling member F contains a foaming agent. Therefore, when the filling member F is placed in the gap of the transition portion 50 , the foaming agent foams, thereby completely filling the gap of the transition portion 50 .

[0063] Furthermore, the gap between the radial side surface of the winding 10 and the radial inner side surfaces of the first cover portion 30 and the second cover portion 40 is smaller than the gap between the conductive wires L constituting the winding 10. As a result, the refrigerant C can easily flow between the conductive wires L constituting the winding 10 within the first cover portion 30 and the second cover portion 40. This improves the cooling efficiency of the refrigerant C within the winding.

[0064] Furthermore, the radial side surfaces of the winding 10 are in contact with the radial inner side surfaces of the first cover portion 30 and the second cover portion 40. Thus, the shapes of the first cover portion 30 and the second cover portion 40 eliminate gaps in the transition portion. This ensures that the refrigerant C can reliably enter the gaps between the wires L that constitute the winding 10.

[0065] Furthermore, the first cover portion 30 and the second cover portion 40 have protrusions 30P that protrude toward the winding 10. Thus, in the transition portion 50, only the protrusions 30P can be brought into contact with the winding 10. Thus, for example, by simply changing the shapes of the first cover portion 30 and the second cover portion 40 in an existing product, the effects of the embodiments of the present invention can be achieved.

[0066] The space factor of the portion of the winding 10 located at the transition portion 50 is lower than the space factor of the portion located at the slot 20S. By increasing the gap in the portion of the winding 10 located at the transition portion 50, the refrigerant C can easily enter the interior of the winding 10.

[0067] It should be noted that the technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0068] For example, the protrusion 30P is Figure 6 The center portion protrudes at a right angle from the first cover portion 30 toward the overlap line 11, but may also protrude in a tapered shape.

[0069] Furthermore, within the scope not departing from the gist of the present invention, components in the aforementioned embodiments may be appropriately replaced with well-known components, and the aforementioned modifications may be appropriately combined.

Claims

1. A rotating electrical machine comprising: winding; a stator core having slots for the windings; a cover portion covering the stator core; and a transition portion formed by the cover portion and the stator core, A gap between a radial side surface of the winding and a radial inner side surface of the cover portion is smaller than a gap between conductive wires constituting the winding.

2. The rotating electrical machine according to claim 1, wherein The radial side surface of the winding is in contact with the radial inner side surface of the cover.

3. The rotating electrical machine according to claim 1 or 2, wherein: The cover portion has a protrusion protruding toward the winding.

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