JP6374798B2 - Cooling structure of rotating electric machine - Google Patents

Description

  The present invention relates to a rotating electrical machine cooling structure applied to automobiles and industrial equipment.

Electric motors (including various PM motors / generators) applied to industrial equipment such as automobiles, agricultural machinery, construction equipment, utility vehicles, etc. are mounted on equipment as series hybrid type or parallel hybrid type driving sources. Small and high output permanent magnet synchronous motors are used.
In this type of electric motor stator, the coil is concentrated or distributedly wound around the teeth protruding from the yoke, and in order to dissipate the heat generated by the copper loss of the coil and the heat generated by the iron loss of the stator, Direct cooling using automatic transmission fluid (ATF), liquid cooling using a water jacket for the outer case, etc. are implemented.

In the ATF cooling, the contact area between the coil and the refrigerant is small, the amount of heat transfer is small, and it is difficult to cool the vicinity of the coil. In the water jacket cooling of the outer case, there is a gap between the stator and the outer case. Has an air layer, a large thermal resistance, and a long distance to the coil, so that the heat radiation efficiency is low.
In Patent Document 1, there is one in which an electromagnetic coil wound around an iron core is molded with a mold resin and the high thermal conductivity of the mold resin is used.

  Further, in Patent Document 2, a refrigerant supply port is disposed apart from the coil in the axial direction of the stator, and the refrigerant is supplied from the refrigerant supply port to the axial end surface and the circumferential end surface of the coil. In some cases, the cooling efficiency is improved by contacting them.

WO2012 / 101976A1 specification JP 2014-096876 A

In the technique of Patent Document 1, heat conduction from the electromagnetic coil to the mold resin can be performed efficiently, but the outer case must also be formed of the mold resin, and when placed in a metal outer case, Heat dissipation from the mold resin to the outside becomes difficult.
Although the technique of the said patent document 2 can cool the surrounding surface of a coil directly, since the time for which a refrigerant | coolant contacts a coil is short, it becomes difficult to raise cooling efficiency.

An object of the present invention is to provide a cooling structure for a rotating electrical machine that can solve such problems of the conventional technology.
The present invention provides a cooling structure for a rotating electrical machine that can efficiently cool a winding by forming a passage for refrigerant inside a heat conductor made of a high thermal conductivity resin that covers the winding of a tooth. With the goal.

Specific means for solving the problems in the present invention are as follows.
Cooling structure of a rotating electric machine according to an embodiment of the present invention, an annular yoke 2, a stator 1 having the teeth 3 are arranged at intervals in the protruding and circumferential direction from the inner peripheral side of the yoke 2 The winding 5 wound around the teeth 3 and spaced between the windings 5 adjacent in the circumferential direction, and the axis of the stator 1 while filling the space between the windings 5 a center direction sides thermal conductor 7 which is molded with resin of high thermal conductivity, a passage 8 for a refrigerant flow formed inside of the heat conductor 7, ring shape along the yoke 2 the have exhibited, characterized in that it comprises a position wherein the windings 5 and by the teeth 3 overlap, and the yoke 2 and the overlapped position and the disposed passageway 8.

A passage 8 disposed at a position overlapping the winding 5 and the teeth 3 and a passage 8 disposed at a position overlapping the yoke 2 are concentrically annular in the radial direction of the yoke 2. It is formed .
The passage 8 is characterized in that the inner surface of the passage through which the refrigerant flows is made of a resin forming the heat conductor 7 .

According to the present invention, the winding can be efficiently cooled.
That is , by filling the space between the windings 5 and molding the heat conductor 7 with a resin having high thermal conductivity on both sides in the axial direction of the stator, the resistance from the winding 5 is reduced with the large volume heat conductor 7. Heat can be taken away, and the heat can be efficiently cooled by the refrigerant passing through the refrigerant passage 8 in the heat conductor 7.

Further, the heat conductor 7 can be molded by filling a resin having a high thermal conductivity between the windings 5, and heat can be conducted from the entire circumference of the winding 5 to the heat conductor 7. It is possible to efficiently cool with the refrigerant in the refrigerant passage 8 arranged in an overlapping manner.
Further, the side surface in the axial direction of the stator 1 has a wide area, and the heat conductor 7 can be cooled in the wide area portion, and the cooling efficiency can be increased.

1 is a perspective view showing a first embodiment of the present invention. It is the XX sectional view taken on the line of FIG. It is the YY sectional view taken on the line of FIG. It is a Z arrow line view of FIG. It is a front view which shows 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the first embodiment shown in FIGS. 1 to 4, for example, a stator 1 applied to a synchronous motor (rotary electric machine) having a permanent magnet embedded rotor is shown. It is press-fitted into the inner peripheral surface.
In the stator 1, a plurality of teeth 3 are arranged in the circumferential direction so as to protrude from the inner peripheral side of the annular yoke 2, and a winding 5 is wound around the teeth 3 with an insulating member 4 interposed therebetween. The heat conductor 7 is molded with a resin having a high thermal conductivity over the entire stator 1 while leaving the inner diameter end of 5, and a refrigerant passage 8 is formed inside the heat conductor 7.

The stator 1 is of a yoke-integrated type in which a large number of teeth 3 project from the inner periphery of one annular yoke 2, but a divided yoke and a single tooth 3 (pole tooth portion) integrated therewith. And a stator piece annular coupling type in which a plurality of stator pieces are arranged in the circumferential direction to form one annular stator.
The stator 1 is formed by laminating a large number of silicon steel plates, and the teeth 3 have two surfaces in the circumferential direction (surface on the slot side) and two surfaces in the axial direction (axial direction of the stator). The cross section is rectangular.

The insulating member 4 is formed of resin such as aramid insulating paper or PPS resin, and surrounds the entire circumference of the teeth 3 having a rectangular cross section, or surrounds the entire circumference of the teeth 3 as a pair. It has a split shape.
Note that protrusions are formed on the circumferential surface and / or the axial surface of the tooth 3, and concave grooves that fit into the protrusions are formed on the inner peripheral surface of the insulating member 4, thereby increasing the contact area between the two. In addition, the air layer may be difficult to form, and the fitting position of the insulating member 4 with respect to the tooth 3 may be fixed.

The winding 5 is wound by concentrated winding, and the insulating member 4 is fitted to the tooth 3, and the winding 5 is concentrated and wound around the outer periphery of the insulating member 4.
The heat conductor 7 is a resin having a high heat conductivity. By placing the stator 1 in a mold and filling the resin, the resin is filled between the windings 5 and the outer shape is also a cross section. It is formed in a rectangular shape or other shapes. This molding can be performed before or after the stator 1 is fitted into the outer case 10.

When performing the molding, a resin tube, a metal tube, or a rod-like core formed of a heat-meltable material is formed into an annular shape and inserted into the mold, thereby cooling the coolant. A service passage 8 is formed.
The refrigerant passages 8 shown in FIGS. 1 to 4 are four, and three are disposed at positions overlapping the windings 5 and the teeth 3, and one is disposed at a position overlapping the yoke 2. The four refrigerant passages 8 are wound around four concentric ring-shaped circles, a common refrigerant supply port member 13 is provided at one end of the four passages 8, and common to the other four ends. A refrigerant discharge port member 14 is provided.

The refrigerant supply port member 13 and the refrigerant discharge port member 14 are connected to a refrigerant circulation device outside the stator 1, and supply a refrigerant such as cooled water or oil to the refrigerant supply port member 13 to supply a refrigerant passage. 8 and is discharged from the refrigerant discharge port member 14.
The four refrigerant passages 8 can also be formed by winding one passage into a quadruple spiral. In this case, the refrigerant discharge port member 13 is connected to one end and the refrigerant discharge port is connected to the other end. The member 14 is connected.

  FIG. 5 shows a second embodiment, in which the refrigerant passages 8 in the heat conductor 7 are arranged on both side surfaces of the stator 1 in the axial direction, and the yoke 2 has oval cross-sections on both side surfaces. The auxiliary passage 16 is formed. The auxiliary passage 16 overlaps the side surface of the yoke 2 in the axial direction and overlaps the outer end portion of the winding 5 so that the winding 5 and the yoke 2 can be cooled. Also in the outer case 10, a cooling path 17 is formed through which the refrigerant passes on the inner peripheral side in the vicinity of the yoke 2.

In the first and second embodiments, the refrigerant passage 8 is formed in a mesh shape or a circumferential zigzag shape when viewed in the axial direction, and is disposed in the heat conductor 7 or from the side of the winding 5. The windings 5 adjacent to each other in the direction may be inserted, or the windings 5 adjacent to each other in the circumferential direction may be sewn.
The refrigerant passage 8 may be circular, oval, rectangular, or other shape in cross section, and may be one or a plurality of refrigerant passages disposed on at least one side surface in the axial direction of the stator 1. Although it can be arranged at a position overlapping with the yoke 2, it is arranged at least at a position overlapping with the winding 5 and a position where the coil end can be cooled.

In the rotating electrical machine incorporating the stator 1, the heat conductor 7 made of high thermal conductivity resin is filled between the windings 5 and covers both side surfaces in the axial direction of the winding 5, the teeth 3 and the yoke 2, The resistance heat generated in the winding 5 and the teeth 3 is efficiently conducted and absorbed, and can be removed by the refrigerant flowing through the refrigerant passage 8.
Only the high thermal conductivity resin is provided between the winding 5 serving as a heating element and the refrigerant passage 8, and the thermal resistance is lowered, and the heat conductor 7 itself is cooled by the refrigerant passing through the refrigerant passage 8 to be resistant. Since heat can be taken away, it can cool efficiently. In addition, since the refrigerant passage 8 is integrally formed in the heat conductor 7, the number of parts can be reduced, and molding is easy.

The refrigerant passage 8 can be disposed in the vicinity of the coil end of the winding 5 inside the heat conductor 7, and is disposed on both sides of the winding 5, both sides of the yoke 2, etc., so that the stator 1 is entirely and uniformly arranged. It is possible to cool the rotating electric machine and keep the temperature of the winding 5 low, thereby extending the life of the rotating electrical machine.
Improving the cooling efficiency with the refrigerant makes it possible to reduce the structure of fins and the like in the rotating electrical machine, and to reduce the forced cooling system to a low output, thereby reducing vibration and noise. .

Moreover, since the stator 1 has the heat conductor 7 that covers the outer surface, the outer peripheral surface of the stator 1 and the inner peripheral surface of the outer case 10 can be fixed with rough accuracy, and the cost can be reduced. In the case of a flat rotating electric machine, a larger cooling area and cooling volume than those without the heat conductor 7 can be secured.
In the present invention, the shape of each member and the positional relationship between the front, back, left, and right in the above embodiment are best configured as shown in FIGS. However, it is not limited to the said embodiment, A member, a structure can be variously deformed, and a combination can also be changed.

  For example, the winding 5 is wound by concentrated winding, but may be distributed winding that winds the winding over a plurality of teeth 3.

1 Stator 2 Yoke 3 Teeth 4 Insulating Member 5 Winding 7 Heat Conductor 8 Refrigerant Passage

Claims (3)

A stator (1) having an annular yoke (2) and teeth (3) projecting from the inner peripheral side of the yoke (2) and arranged at intervals in the circumferential direction ;
A winding (5) wound around the teeth (3) and spaced between adjacent windings (5) in the circumferential direction;
The winding (5) axial direction sides to be molded with resin of high thermal conductivity heat conductor of the stator (1) while filling between the (7),
A the heat conductor (7) formed inside the passage for the refrigerant flow (8), they exhibit a ring shape along the yoke (2), the winding (5) and the teeth ( 3) and a passage (8) arranged at a position overlapping with the yoke (2) ,
Cooling structure of a rotating electric machine, characterized in that it comprises a. The passage (8) disposed at a position overlapping with the winding (5) and the tooth (3), and the passage (8) disposed at a position overlapping with the yoke (2) are provided in the yoke. 2. The cooling structure for a rotating electric machine according to claim 1, wherein the cooling structure is formed concentrically in the radial direction of (2) . 3. The cooling structure for a rotating electrical machine according to claim 1, wherein the passage (8) is formed of a resin that forms the heat conductor (7) on an inner surface of the passage through which a refrigerant flows .

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