JP2016144270A - Cooling structure of rotating electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure the strength of a water jacket of a rotating electric machine and improve the cooling efficiency.
SOLUTION: An annular stator 4 in which a winding 3 is wound is provided on the inner periphery of a water jacket 2 having a jacket passage 2a through which a refrigerant is passed, and the winding 3 and the stator 4 are made of a highly heat conductive resin. The heat conductor 5 that covers and is integrated with the inner peripheral surface 2b of the water jacket 2 is molded, and the water jacket 2 is formed of a material having high thermal conductivity and is mounted in a separate motor housing 6.
[Selection] Figure 1

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.
Of these types of motors, especially in flat and thin motors, in order to obtain the required cooling water channel length, the water channel width tends to be larger than the stator stacking thickness. The contact area is limited and it is difficult to perform effective cooling. For this reason, sufficient cooling cannot be performed, and the continuous use time of the motor at a high output is restricted.

  The electric motor of Patent Document 1 includes a stator body provided in a motor housing, a stator having a stator coil wound around the stator body, and a rotor rotatably inserted in the stator, and an end surface of the stator body The resin is provided around the gap between the coil end windings provided on the surface of the coil end portion protruding from the stator body in the gap between the motor housing and the inner wall surface of the motor housing, A water jacket is formed in a double structure with the cylindrical portion, and the stator coil and the heat of the stator are absorbed by a cooling medium passing through a gap (jacket passage) therein.

Japanese Patent Laid-Open No. 10-290543

  In the conventional technology, in addition to the heat transfer path from the outer periphery of the stator to the water jacket, the heat transfer path from the stator coil and the stator surface to the water jacket through the resin can be used, so that the cooling efficiency can be increased. However, since a jacket passage serving as a cooling medium flow passage is formed in the motor housing, the motor housing itself is unlikely to be a strength member, and the motor housing having the jacket passage and the stator are coupled by shrinkage. As a result, the thermal resistance may increase, leading to a reduction in cooling capacity.

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 heat conductor integrated on the inner peripheral surface of the water jacket so as to cover the winding and the stator, and the water jacket is mounted in a separate motor housing, thereby ensuring the strength of the water jacket. It is an object of the present invention to provide a cooling structure for a rotating electrical machine that can improve cooling efficiency.

Specific means for solving the problems in the present invention are as follows.
First, an annular stator 4 in which a winding 3 is wound is provided on the inner periphery of a water jacket 2 having a jacket passage 2a through which a refrigerant is passed, and the winding 3 and the stator 4 are made of high heat conductive resin. The heat conductor 5 that covers and is integrated with the inner peripheral surface 2b of the water jacket 2 is molded, and the water jacket 2 is formed of a material having high thermal conductivity and is mounted in a separate motor housing 6. It is characterized by that.

Second, the water jacket 2 is formed of an aluminum alloy, the motor housing 6 is formed of iron-based casting, and the water jacket 2 is wound around the inner peripheral surface 2b of the water jacket 2 before being mounted in the motor housing 6. The heat conductor 5 covering the wire 3 and the stator 4 is molded.
Third, the water jacket 2 has a cylindrical shape, and the jacket passage 2a therein is formed in a circumferential zigzag shape with a width extending between both axial ends.

Fourth, the heat conductor 5 is formed such that the width in the axial direction of the stator 4 is wider on the outer side than the inner side, and the outer side is made to correspond to the substantially full width in the axial direction of the water jacket 2. And
Fifth, it is characterized in that a passage 8 for circulating refrigerant is formed inside the heat conductor 5 so as to overlap the stator 4 and the winding 3.

According to the present invention, it is possible to ensure the strength of the water jacket of the rotating electrical machine and improve the cooling efficiency.
That is, in the invention according to claim 1, the winding 3, the stator 4, and the heat conductor 5 covering them are molded on the inner periphery of the water jacket 2 in which the jacket passage 2 a is formed, and the water jacket 2 has a high thermal conductivity. Since it is formed of the above material and mounted in a separate motor housing 6, the reinforcing strength of the water jacket 2 can be secured while improving the cooling efficiency.

In the invention according to claim 2, since the water jacket 2 is formed of a high strength iron-based cast motor housing 6 while being formed of an aluminum alloy having a high thermal conductivity, the water jacket 2 is improved while improving the cooling efficiency. Strength can be secured more reliably.
In the invention according to claim 3, since the jacket passage 2a is formed in a circumferential zigzag shape with a width extending between both axial ends of the cylindrical water jacket 2, the circulating refrigerant cools the water jacket 2 efficiently. be able to.

In the invention according to claim 4, the heat conductor 5 is formed such that the width in the axial direction of the stator 4 is wider on the outer side than the inner side, and the outer side is made to correspond to substantially the entire width of the water jacket 2 in the axial direction. Therefore, heat conduction from the heat conductor 5 to the water jacket 2 can be efficiently and effectively performed with a small amount of material.
In the invention according to claim 5, the refrigerant flow passage 8 is formed inside the heat conductor 5 so as to overlap the stator 4 and the winding 3, so that the refrigerant 4 is close to the stator 4 and the winding 3. The heat conductor 5 itself can be efficiently cooled.

It is a perspective explanatory view showing a 1st embodiment of the present invention. It is the same section sectional front view. It is the same hierarchy fracture | rupture side explanatory drawing. It is a perspective explanatory view showing a jacket passage of a water jacket. It is a perspective explanatory view showing a 2nd embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the first embodiment shown in FIGS. 1 to 4, a fixed side of a flat and thin synchronous motor (rotating electric machine 1) is shown. An annular stator 4 is provided on the inner periphery of the water jacket 2, and a large number of stators 4 are provided. The winding 3 is wound around the teeth 4B, and the heat conductor 5 is molded on the inner peripheral surface 2b of the water jacket 2 so as to cover the winding 3 and the stator 4, and the water jacket 2 is placed in the motor housing 6. A permanent magnet embedded rotor 7 (shown in FIG. 2) is arranged inside the stator 4.

  The water jacket 2 is made of an aluminum alloy having a high thermal conductivity and is formed in a cylindrical shape, and a jacket passage 2a having a zigzag shape in the circumferential direction is formed inside. The jacket passage 2a has a plurality of straight holes a1 extending in the axial direction in parallel with each other in the circumferential direction. The adjacent straight holes a1 communicate with each other at the communication groove a2 and the other end is adjacent to the other. The other end of the straight hole a1 is formed to communicate with the communication groove a3.

The communication grooves a2 and a3 are closed by seal rings 12 disposed at both axial ends of the water jacket 2, and a jacket passage 2a is formed in the water jacket 2 with a width extending between both axial ends.
Both ends of the jacket passage 2a are open to the outer peripheral surface of the water jacket 2, one end is a refrigerant supply port a4 and the other end is a refrigerant discharge port a5, which is connected to an external refrigerant circulation device, and is cooled with water or oil It is possible to circulate such refrigerant.

The stator 4 has a plurality of teeth 4B arranged in the circumferential direction with the teeth 4B projecting on the inner peripheral side of the annular yoke 4A. The teeth 4B have a widened end, and the winding 3 The thermal conductor 5 is molded with a resin having a high thermal conductivity over the entire stator 4 except for the radially inner ends of the teeth 4B and the windings 3.
The stator 4 is a yoke-integrated type in which a large number of teeth 4B project from the inner periphery of one annular yoke 4A, but the divided yoke and one tooth 4B (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 4 is formed by laminating a large number of silicon steel plates, and the teeth 4B 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 11 is made of resin such as aramid insulating paper or PPS resin, and surrounds the entire circumference of the teeth 4B having a rectangular cross section, or surrounds the entire circumference of the teeth 4B in pairs. It has a split shape.

The winding 3 is wound in a concentrated manner. The insulating member 11 is fitted to the teeth 4B, and the winding 3 is tightened around the outer periphery of the insulating member 11 while the winding 3 is tightened.
The thermal conductor 5 is a resin having a high thermal conductivity (for example, a resin having a thermal conductivity of 3 to 5 Wm ² K). The stator 4 is disposed in the mold and filled with the resin, The resin is filled between the lines 3 and the outer shape is formed in a rectangular cross section or other shapes.

  The heat conductor 5 is formed by inserting the stator 4 into the water jacket 2 and using the water jacket 2 as a part of the mold to fill the mold with high thermal conductivity resin by injection or transfer. To mold. The high thermal conductivity resin serves as a filler that fills the space and gaps around the winding 3 and the stator 4 on the inner peripheral surface 2b side of the water jacket 2. It is fixed to the jacket 2.

The heat conductor 5 has tapered sides on both sides in the axial direction of the stator 4, and the width W1 in the axial direction on the outer diameter side is formed wider than the width W2 on the inner side in the radial direction. This corresponds to substantially the entire width of the jacket 2 in the axial direction, and heat can be conducted from the entire outer peripheral surface of the heat conductor 5 to the water jacket 2.
The heat conductor 5 may be formed to have the same width from the outer peripheral portion to the inner peripheral portion, but the material can be reduced if the inner peripheral portion is narrowed and the cross-sectional circumferential shape is a fan shape or a trapezoidal shape. .

The motor housing 6 is formed of an iron-based casting such as FC or FCD, and is fitted and attached to the outer periphery of the water jacket 2 formed separately.
FC, FCD, etc. have a tensile strength of 200 to 500 MPa, a thermal conductivity of 20 to 40 W / (mK), an aluminum alloy has a tensile strength of 300 MPa, and a thermal conductivity of 130 to 180 W / (mK), An aluminum alloy that is easy to transmit heat is applied to the water jacket 2, an iron-based casting having a tensile strength of 300 MPa or more is applied to the motor housing 6 that becomes the outer case, and the motor housing 6 is a structural strength member for protecting the strength of the water jacket 2. I have to.

In the second embodiment shown in FIG. 5, the stationary side of the rotating electrical machine 1 is provided with a stator 4 in which a water jacket 2 is mounted in a motor housing 6, and a winding 3 is wound around the inner periphery of the water jacket 2. A heat conductor 5 is molded on the inner peripheral surface 2 b of the water jacket 2 so as to cover the winding 3 and the stator 4, and a refrigerant passage 8 is formed inside the heat conductor 5.
The water jacket 2 is formed of a high thermal conductivity aluminum alloy in a cylindrical shape, a jacket zigzag jacket passage 2a is formed inside, and the stator 4 is formed by laminating a large number of silicon steel plates. The tip is not a divergent shape, but has a rectangular cross section from the trunk to the tip. The insulating member 11 is formed of an elastic resin, and the winding 3 is wound around the outer periphery thereof in a concentrated manner.

The heat conductor 5 is formed by placing a stator 4 in a mold and filling a high thermal conductivity resin. When performing this molding, a resin tube, a metal The refrigerant passage 8 is formed by forming a tube-shaped core or a rod-shaped core made of a heat-meltable material into an annular shape and inserting it into the mold.
The heat conductor 5 is gradually narrowed from the outer peripheral portion in contact with the water jacket 2 to the inner peripheral portion side in the axial direction of the stator 4, but even if formed in the same width from the outer peripheral portion to the inner peripheral portion. A plurality of refrigerant passages 8 are formed between the stator 4 and both axial side surfaces.

  Three refrigerant passages 8 are formed on both sides of the stator 4 in the axial direction, two are disposed at positions overlapping the winding 3 and the teeth 4B, and one is disposed at a position overlapping the yoke 4A. . The three refrigerant passages 8 are wound around three concentric ring-shaped circles, and a common refrigerant supply port member 13 is provided at one end of the three passages 8. A refrigerant discharge port member 14 is provided. The refrigerant passage 8 may be only one side of the stator 4, and the number may be one or a plurality other than three.

The refrigerant supply port member 13 and the refrigerant discharge port member 14 are connected to a refrigerant circulation device outside the stator 4, and supply 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 three refrigerant passages 8 can also be formed by winding a single passage in a triple helix. In this case, the refrigerant supply port member 13 is connected to one end and the refrigerant discharge port is connected to the other end. The member 14 is connected.

  Out of the three refrigerant passages 8, the outer peripheral side and the intermediate peripheral side are circular in cross section, and the inner peripheral side is deformed to have an oval cross section because the inner peripheral portion of the heat conductor 5 is narrow. The refrigerant passage 8 may be circular, oval, rectangular, or other shape in cross section, and may be one or more and disposed on at least one side surface of the stator 4 in the axial direction. Although it can be disposed at a position overlapping with the yoke 4A, it is disposed at least at a position overlapping with the winding 3 and at a position where the coil end can be cooled.

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 5 or enters between the windings 3 adjacent in the circumferential direction from the side of the winding 3. Alternatively, the windings 3 adjacent to each other in the circumferential direction may be sewn.
The rotating electric machine 1 absorbs and absorbs the resistance heat generated in the winding 3 and the teeth 4B to the water jacket 2 through the yoke 4A and is filled between the windings 3 and the windings 3, the teeth 4B and The heat conductor 5 made of a high thermal conductivity resin covering the yoke 4A is also absorbed, and in addition to the direct heat conduction from the yoke 4A, the wide outer peripheral surface of the heat conductor 5 is made of a material having a high thermal conductivity. By being in contact with the water jacket 2, the heat conduction efficiency can be increased and the resistance heat can be conducted to the water jacket 2, and the water jacket 2 can be efficiently cooled by the refrigerant flowing through the jacket passage 2a formed over the entire width. By making 2 a part of the mold, the heat conductor 5 can be easily molded, and the stator 4 is made into the water jacket 2 by the heat conductor 5. Chakudeki, the water jacket 2 can be reinforced by the motor housing 6 of the structural strength members.

Then, when the refrigerant passage 8 is formed in the heat conductor 5 and the refrigerant is circulated, the heat conductor 5 itself is cooled at a position closer to the winding 3 than the heat conduction path via the yoke 4A, and the resistance heat is taken away. The cooling efficiency can be improved and the refrigerant passage 8 is integrally formed in the heat conductor 5, so that the number of parts can be reduced.
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, a material, etc. can be variously deformed and a combination can also be changed.

For example, in the first embodiment, the jacket passage 2a has communication grooves a2 and a3 formed annularly at both ends of the water jacket 2, respectively, and a plurality of circumferential holes a1 in the circumferential direction are formed in both the annular communication grooves a2 and a3. You may make it make the both ends communicate.
Although the winding 3 is wound by concentrated winding, you may make it the distributed winding which winds a winding over the several teeth 4B.

DESCRIPTION OF SYMBOLS 1 Rotating electrical machine 2 Water jacket 2a Jacket passage 2b Inner peripheral surface 3 Winding 4 Stator 4A Yoke 4B Teeth 5 Thermal conductor 6 Motor housing 8 Refrigerant passage 11 Insulating member 12 Seal ring W1, W2 Width

Claims (5)

  An annular stator (4) around which a winding (3) is wound is provided on the inner periphery of a water jacket (2) having a jacket passage (2a) through which a refrigerant is passed. ) And the stator (4) and a heat conductor (5) integrated with the inner peripheral surface (2b) of the water jacket (2) is molded, and the water jacket (2) is made of a material having a high thermal conductivity. And a cooling structure for a rotating electric machine, wherein the cooling structure is mounted in a separate motor housing (6).   The water jacket (2) is formed of an aluminum alloy, the motor housing (6) is formed of iron-based casting, and the water jacket (2) is attached to the motor housing (6) before the water jacket (2) is mounted. The cooling structure for a rotating electric machine according to claim 1, wherein a heat conductor (5) covering the winding (5) and the stator (4) is molded on the inner peripheral surface (2b).   The said water jacket (2) is a cylindrical shape, The jacket channel | path (2a) in the inside is formed in the circumferential direction zigzag shape by the width | variety ranging between axial center both ends. The rotating electrical machine cooling structure described in 1.   The heat conductor (5) has a width in the axial direction of the stator (4) wider than the inner diameter of the stator (4), and the outer diameter corresponds to substantially the entire width of the water jacket (2) in the axial direction. The cooling structure for a rotating electrical machine according to any one of claims 1 to 3.   The refrigerant passage (8) is formed in the heat conductor (5) so as to overlap the stator (4) and the winding (5). The cooling structure for a rotating electrical machine according to any one of the preceding claims.

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