JP6850219B2 - Stator core - Google Patents

Description

The present invention relates to a stator core that can be cooled efficiently.

The stator of a rotary electric machine is configured by winding a winding around a stator core. The temperature of the stator rises due to heat generated by copper loss and eddy current loss when the rotary electric machine operates. Therefore, a method is known in which a refrigerant such as cooling oil is dropped from the refrigerant supply pipe to the outer peripheral surface of the stator core to cool the refrigerant. In the cooling method by dropping the refrigerant, the refrigerant flows down immediately along the outer peripheral surface of the stator core, so that the refrigerant does not spread evenly. In some cases, a sufficient cooling effect could not be obtained in the central part. Patent Document 1 discloses a liquid-cooled motor in which a large number of silicon steel plates having notches on the outer periphery are laminated and the notches are continuous in the circumferential direction to form a spiral refrigerant passage. ..

Japanese Unexamined Patent Publication No. 7-264810

However, according to the liquid-cooled motor described in Patent Document 1, a spiral refrigerant passage having continuous notches is arranged on the outer periphery of the stator core, but the refrigerant immediately flows down in the spiral groove, and the stator core There is a possibility that sufficient cooling time may not be secured due to the heat receiving from the refrigerant to the refrigerant, resulting in insufficient cooling. In addition, there is a possibility that the cooling capacity of the central portion of the stator core, which tends to become hot, is insufficient.

An object of the present invention is to provide a stator core having high cooling performance with an inexpensive and simple structure.

In order to achieve the above object, the invention according to claim 1 is
It is a stator core (for example, the stator core 10 in the embodiment described later) configured by laminating a plurality of steel plates (for example, the steel plate 11 in the embodiment described later).
On the outer peripheral surface of the stator core (for example, the outer peripheral surface 15 in the embodiment described later), a refrigerant storage portion for storing the refrigerant in a region including the axially central portion of the stator core (for example, the refrigerant storage in the embodiment described later). part S) is formed,
The steel plate is
A first steel plate in which a first recess (for example, a recess 17B in the embodiment described later) is formed on the outer peripheral surface of the first region (for example, the first region P1 in the embodiment described later).
A second steel sheet in which a second recess (for example, a recess 17A in the embodiment described later) is formed on an outer peripheral surface of a second region (for example, the second region P2 in the embodiment described later) different from the first region. And, including
By arranging the first steel plate and the second steel plate so as to overlap each other, the refrigerant storage portion is formed.
It said first recess and said second recess, that the central portion in the axial direction of the stator core having a V-shaped recessed in the circumferential direction.

Further, in the invention according to claim 2 , in the invention according to claim 1 ,
An inclined surface (for example, an inclined surface 22 in the embodiment described later) that is smoothly inclined in the circumferential direction is connected to the refrigerant storage portion.

According to the first aspect of the present invention, since the refrigerant storage portion for storing the refrigerant is formed in the region including the axially central portion of the stator core on the outer peripheral surface of the stator core, the shaft of the stator core which has been difficult to cool up to now. The outer peripheral surface of the central portion in the direction can be appropriately cooled.
Further, the first steel plate having the first concave portion formed on the outer peripheral surface of the first region and the second steel plate having the second concave portion formed on the outer peripheral surface of the second region are arranged so as to overlap each other on the outer peripheral surface. Since the refrigerant storage portion is formed, the outer peripheral surface of the stator core can be appropriately cooled by the refrigerant remaining in the refrigerant storage portion while increasing the surface area of the stator core and improving the heat dissipation capacity.
Further, since the first recess and the second recess have a V-shape in which the central portion in the axial direction of the stator core is recessed in the circumferential direction, the outer peripheral surface of the central portion in the axial direction of the stator core, which has been difficult to cool up to now, is appropriately cooled. be able to.

According to the second aspect of the present invention, since the refrigerant storage unit is connected to an inclined surface that inclines smoothly in the circumferential direction, the discharge property of the refrigerant is improved and the refrigerant stays in the refrigerant storage unit. It can be prevented from continuing to do so.

It is a perspective view of the stator core of 1st Embodiment of this invention. It is a front view of the steel plate which constitutes the stator core shown in FIG. It is explanatory drawing explaining the assembly method of the stator core shown in FIG. It is a perspective view of the stator core of 2nd Embodiment. It is a front view of the steel plate which constitutes the stator core shown in FIG. It is an enlarged view of the part A of FIG. It is a perspective view of the stator core of the modification of 2nd Embodiment. It is a perspective view of the stator core of 3rd Embodiment.

Hereinafter, each embodiment of the present invention will be described with reference to the drawings.

(First Embodiment)
FIG. 1 is a perspective view of the stator core of the first embodiment. As shown in FIG. 1, the stator core 10 of the present embodiment is formed by laminating a plurality of steel plates 11 (see FIG. 2) such as electromagnetic steel plates, and has a substantially annular stator core main body 12 and an outer peripheral portion of the stator core main body 12. It has a plurality of stator core fixing portions 13 (four in the embodiment shown in the figure) provided at equal intervals in the circumferential direction. The stator core fixing portion 13 is provided with a bolt through hole 14 through which a bolt for fixing the stator core 10 to a housing (not shown) or the like is inserted.

Further, the stator core 10 is arranged in a posture in which the center line O (rotational axis of the rotor (not shown) is inclined with respect to the horizontal plane. A refrigerant supply pipe 25 is arranged above the stator core 10 (upper right in the example of FIG. 1), and a refrigerant R such as cooling oil is transferred from the refrigerant supply pipe 25 to the upper right upper surface 31 of the outer peripheral portion described later of the stator core 10. Dropped.

FIG. 2 is a front view of the steel plate constituting the stator core shown in FIG. As shown in FIG. 2, the steel plate 11 is provided with grooves 16A and 16B in different phases in the circumferential direction. Specifically, of the four outer peripheral surfaces 15 of the stator core main body 12 formed between the stator core fixing portions 13, a pair of outer peripheral surfaces 15A arranged on both sides in the circumferential direction with one stator core fixing portion 13A interposed therebetween. A pair of grooves 16A and 16B are formed in 15B by cutting out a pair of grooves 16A and 16B in a region close to the stator core fixing portion 13A in the circumferential direction, respectively.

More specifically, from the circumferential center line CL connecting the intermediate portion of the outer peripheral surface 15A and the center line O of the stator core 10 to the outer peripheral surface 15A on one of the circumferential directions (upper left side in FIG. 2) of the stator core fixing portion 13A. A groove 16A is formed in a region of α ° toward the stator core fixing portion 13A, and an intermediate portion of the outer peripheral surface 15B and the stator core are formed on the outer peripheral surface 15B of the other peripheral surface (upper right side in FIG. 2) of the stator core fixing portion 13A in the circumferential direction. A groove 16B is formed in a region of α ° from the circumferential center line CL connecting the center line O of 10 toward the stator core fixing portion 13A.

As shown in FIG. 3A, the plurality of steel plates 11 are laminated in phase with each other to form recesses 17A and 17B extending in the stacking direction on the outer peripheral surfaces 15A and 15B by the grooves 16A and 16B. Then, as shown in FIG. 3B, the plurality of laminated steel plates 11 are divided into two blocks B1 and B2 at substantially the center in the stacking direction, and the block B2 is rotated by 90 ° with respect to the block B1 (FIG. 3). Then, the stator core 10 shown in FIG. 1 is formed by assembling (rolling) in a clockwise direction.

In the following description, the stator core fixing portion 13 in which the stator core fixing portion 13A of the block B1 is located is referred to as a top fixing portion 30, and the outer peripheral surface in which the outer peripheral surface 15B of the block B1 is located is referred to as an outer peripheral right upper surface 31. The outer peripheral surface on which the outer peripheral surface 15A of B1 is located is called the outer peripheral upper left surface 32.

Focusing on the upper right upper surface 31 of the outer peripheral portion of the stator core 10 in FIG. 1 in which the refrigerant supply pipe 25 is arranged, the recess 17B of the block B1 is the first region P1 on the proximal side of the top fixing portion 30 with respect to the circumferential center line CL. The recess 17A of the block B2 is formed in the second region P2 on the distal side of the top fixing portion 30 with respect to the circumferential center line CL. That is, the block is offset on the upper right upper surface 31 of the outer peripheral portion of the stator core 10 in the circumferential direction with the circumferential center line CL in between, and offset in the axial direction with the boundary surface M between the block B1 and the block B2 in between. A recess 17B of B1 and a recess 17A of block B2 are formed.

Returning to FIG. 1, when a refrigerant such as cooling oil dripping from the refrigerant supply pipe 25 is dropped on the upper right upper surface 31 of the outer peripheral portion of the stator core 10, the refrigerant flows into the recess 17B of the block B1 and the recess 17A of the block B2. Flow to. The refrigerant that has flowed into the recess 17A of the block B2 is a refrigerant storage portion formed by a step formed by the boundary surface M between the block B1 and the block B2 located at the axial center of the stator core 10 and the recess 17A of the block B2. Stay in S. By staying the refrigerant in the refrigerant storage portion S for a certain period of time in this way, heat is transferred to and from the stator core 10 to effectively cool the outer peripheral surface of the stator core 10, particularly the axially central portion of the outer peripheral surface.

Further, since the surface area of the stator core 10 is increased by providing the recesses 17A and 17B, it contributes to cooling by heat dissipation. In the present embodiment, the case where the number of transships is one is shown, but the number of transships can be multiple, and the surface area increases as the number of transships increases, that is, as the blocks B1 and B2 are stacked. The heat dissipation efficiency is improved. Although only the recess 17A of the block B1 is formed on the upper left surface 32 of the outer peripheral portion of the stator core 10 in FIG. 1, when the refrigerant supply pipe 25 is also arranged on the upper left surface 32 of the outer peripheral portion of the stator core 10, FIG. By forming a recess on the lower left lower surface of the outer peripheral portion of the stator core 10 of 2, a refrigerant storage portion S can be formed on the upper left surface of the stator core 10 of FIG. 1 by the recess of the block B2 and the end surface of the block B1. .. In the description of the second and subsequent embodiments, the case where the refrigerant storage portion S is formed only on the upper right upper surface of the outer peripheral portion of the stator core 10 will be described as an example.

As described above, according to the stator core 10 according to the present embodiment, the refrigerant storage portion S for storing the refrigerant is formed on the outer peripheral surface 15 of the stator core 10 in the region including the axially central portion of the stator core 10. , The outer peripheral surface of the axially central portion of the stator core 10, which has been difficult to cool up to now, can be appropriately cooled.

Further, the block B1 having the recess 17B formed on the outer peripheral surface of the first region P1 and the second block B2 having the recess 17A formed on the outer peripheral surface of the second region P2 are arranged so as to overlap each other. Since the refrigerant storage section S is formed in the refrigerant storage section S, the outer peripheral surface 15 of the stator core 10 can be appropriately cooled by the refrigerant remaining in the refrigerant storage section S while increasing the surface area of the stator core 10 and improving the heat dissipation capacity.

Further, since the cross-sectional shape of the stator core 10 is different in the stacking direction, the torque waveforms are different at the positions of the recesses 17A and 17B, which also has the effect of reducing the torque ripple.

Further, since the steel plate 11 constituting the block B1 and the steel plate 11 constituting the block B2 have the same shape, the recesses 17A and 17B are arranged so that the phases of the recesses 17A and 17B are different by laminating the block B1 and the block B2. , Only one type of punching die for the steel plate 11 is sufficient, and an increase in manufacturing cost can be suppressed.

(Second Embodiment)
FIG. 4 is a perspective view of the stator core of the second embodiment, and FIG. 5 is a front view of the steel plate constituting the stator core shown in FIG. The difference between the stator core of the second embodiment and the stator core of the first embodiment is the shape of the groove and the number of rolls. Since this point is the same as that of the first embodiment, the same or equivalent parts as those in FIG. 1 are designated by the same reference numerals or equivalent reference numerals to simplify or omit the description.

In the steel plate 11 of the present embodiment, as shown in FIG. 5, the grooves 16C and 16D are in the region of β ° (2α °> β °> α °) from the groove end on the side close to the stator core fixing portion 13A, that is, the stator core is fixed. It is formed in a region beyond the circumferential center line CL (see FIG. 2) from the groove end portion on the side closer to the portion 13A.

By laminating the plurality of steel plates 11 in the same phase, the grooves 16C and 16D form recesses 17C and 17D extending in the laminating direction on the outer peripheral surfaces 15A and 15B. Then, the plurality of laminated steel plates 11 are divided into four blocks B1 to B4 in the stacking direction, the block B2 is rotated by 90 ° with respect to the block B1 (clockwise in FIG. 4), and then the block B3 is divided into the blocks B3. The stator core shown in FIG. 4 is assembled (rolled) by rotating the block B4 by 90 ° with respect to B2 (counterclockwise in FIG. 4) and rotating the block B4 by 90 ° with respect to the block B3 (clockwise in FIG. 4). 10 is formed. That is, the stator core 10 of the second embodiment is formed by stacking blocks B1 to B4 three times.

Focusing on the upper right upper surface 31 of the outer peripheral portion of the stator core 10 in FIG. 4 in which the refrigerant supply pipe 25 is arranged, the recesses 17D of the blocks B1 and B3 are the first on the proximal side of the top fixing portion 30 with respect to the circumferential center line CL. It is formed in the region P1, and the recesses 17C of the blocks B2 and B4 are formed in the second region P2 on the distal side of the top fixing portion 30 with respect to the circumferential center line CL. That is, the recess 17C is offset on the upper right upper surface 31 of the outer peripheral portion of the stator core 10 in the circumferential direction with the circumferential center line CL sandwiched, and offset in the axial direction with the boundary surface M of each block B1 to B4 sandwiched. , 17D is formed.

In the present embodiment, since the grooves 16C and 16D formed in the steel plate 11 are formed in the region beyond the circumferential center line CL, the recesses 17C and 17D of the blocks B1 to B4 are formed so as to be continuous in the axial direction. To.

When a refrigerant such as cooling oil dripping from the refrigerant supply pipe 25 is dropped on the upper right upper surface 31 of the outer peripheral portion of the stator core 10, the refrigerant flows into the recesses 17C and 17D of the blocks B1 to B4. The refrigerant that has flowed into the recess 17C of the block B2 stays in the refrigerant storage portion S formed by the step formed between the boundary surface M between the block B1 and the block B2 and the recess 17C of the block B2, and stays in the recess 17C of the block B4. The inflowing refrigerant stays in the refrigerant storage portion S formed by the step formed in the boundary surface M between the block B3 and the block B4 and the recess 17C of the block B4. By staying the refrigerant in the refrigerant storage portion S for a certain period of time in this way, heat is transferred to and from the stator core 10 to effectively cool the outer peripheral surface of the stator core 10, particularly the axially central portion of the outer peripheral surface.

As described above, according to the stator core 10 according to the present embodiment, the refrigerant storage portion S for storing the refrigerant is formed on the outer peripheral surface 15 of the stator core 10 in the region including the axially central portion of the stator core 10. , The outer peripheral surface of the axially central portion of the stator core 10, which has been difficult to cool up to now, can be appropriately cooled. The axially central portion of the stator core 10 means a portion separated from the end faces of the stator core 10, and does not mean only a portion located equidistant from both end faces of the stator core 10.

Further, the blocks B1 and B3 having the recesses 17D formed on the outer peripheral surface of the first region P1 and the blocks B2 and B4 having the recesses 17C formed on the outer peripheral surface of the second region P2 are arranged so as to overlap each other. Since the refrigerant storage portion S is formed on the surface 15, the outer peripheral surface 15 of the stator core 10 can be appropriately cooled by the refrigerant remaining in the refrigerant storage portion S while increasing the surface area of the stator core 10 and improving the heat dissipation capacity.

Further, by combining the recesses 17C and 17D and providing a plurality of refrigerant storage portions S, the cooling capacity can be improved.

Further, a large amount of refrigerant is stored in the refrigerant storage portion S of the block B2 and effectively cooled, but if the residence time is too long, the temperature of the refrigerant may rise and the cooling effect may be reduced. Therefore, it is desirable that the product is discharged after staying for an appropriate period of time. Therefore, as shown in FIG. 6, it is preferable to provide an inclined surface 22 on the wall 20 of the recess 17C on the downstream side of the refrigerant to discharge the refrigerant after an appropriate residence time.

Further, as shown in FIG. 7, a welded portion 19 for integrally welding the steel plate 11 may be provided inside the recesses 17C and 17D which are continuous in the axial direction in order to prevent the steel plate 11 from coming apart. The welded portion 19 can be formed by a single straight line passing through the recesses 17C and 17D that are continuous in the axial direction, and the welded portion in the conventional stator core in which the recesses are formed in a spiral shape or a ring shape is diagonally or stepped. It can be easily formed as compared with the welded portion to be attached.

The welded portion 19 may be provided with a protrusion (not shown) protruding outward in the radial direction inside the recesses 17C and 17D, and the protrusion may be welded. Since the welded portion 19 is located in the recesses 17C and 17D, the welded portion 19 does not protrude from the outer peripheral surface 15 of the stator core 10, and the degree of freedom in layout of the stator core 10 is improved.

Further, when the refrigerant is injected from the side, the recesses 17C and 17D may be provided with a gradient or a step at which the injection side of the refrigerant is lowered to increase the residence time of the refrigerant.

(Third Embodiment)
FIG. 8 is a perspective view of the stator core 10 of the third embodiment. In the stator core 10 of the third embodiment, the recess 17 is formed in a substantially V shape in which the recess 17 is recessed in the circumferential direction on the upper right upper surface 31 of the outer peripheral portion of the stator core 10. The same or equivalent parts as those in the first embodiment are designated by the same reference numerals or equivalent reference numerals to simplify or omit the description.

As shown in FIG. 4, in the stator core 10 of the present embodiment, the grooves 16 having the same circumferential length are formed so that the circumferential phases are different from each other, for example, the circumferential phases are increased by a predetermined angle. A substantially V-shaped recess 17 that is recessed in the circumferential direction is formed by laminating a large number of steel plates 11 in the order in which the circumferential phase of the groove 16 gradually increases and gradually decreases.

By forming the recess 17 into a substantially V-shape that is recessed in the circumferential direction, the dropped refrigerant is concentrated in the refrigerant storage portion S formed in the vicinity of the V-shaped valley portion 26, and the vicinity of the valley portion 26 is intensively cooled. It becomes possible to do. The position and number of the valleys 26 can be freely set by changing the stacking order of the steel plates 11. Therefore, if the valley portion 26 is set to the center in the axial direction, the outer peripheral surface 15 of the central portion in the axial direction of the stator core 10, which tends to become hot, can be appropriately cooled.

Further, the V-shaped valley portion 26 is not limited to one, and a plurality of V-shaped valley portions 26 can be provided, so that it is possible to effectively cool the portion to be cooled.

As described above, according to the stator core 10 according to the present embodiment, the recess 17 has a V-shape in which the central portion in the axial direction is recessed in the circumferential direction, so that the center in the axial direction of the stator core 10 which has been difficult to cool up to now has been formed. The outer peripheral surface 15 of the portion can be appropriately cooled.

The present invention is not limited to the above-described embodiments, and can be appropriately modified, improved, and the like.
In the first and second embodiments, the refrigerant storage portions are formed by forming recesses in different regions by rolling steel sheets of the same shape, but it is not always necessary to roll steel sheets of the same shape. , A recess may be formed in a different region by laminating steel plates having different shapes, thereby forming a refrigerant storage portion. That is, the first steel plate and the second steel plate may have the same shape or different shapes.

10 Stator core 11 Steel plate 15 Outer peripheral surface 17 to 17D Recessed portion 19 Welded portion 22 Inclined surface P1 First region P2 Second region S Refrigerant storage unit

Claims (2)

It is a stator core composed of a plurality of steel plates laminated together.
On the outer peripheral surface of the stator core, a refrigerant storage portion for storing the refrigerant is formed in a region including the axially central portion of the stator core .
The steel plate is
A first steel plate having a first recess formed on the outer peripheral surface of the first region,
A second steel plate in which a second recess is formed on an outer peripheral surface of a second region different from the first region is included.
By arranging the first steel plate and the second steel plate so as to overlap each other, the refrigerant storage portion is formed.
Said first recess and said second recess, that the central portion in the axial direction of the stator core having a V-shaped recessed in the circumferential direction, the stator core. The stator core according to claim 1.
A stator core to which an inclined surface smoothly inclined in the circumferential direction is connected to the refrigerant storage portion.

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