JP4100170B2 - Cooling structure of rotating electric machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cooling structure for a rotating electrical machine that suppresses heat generation of the rotating electrical machine (such as a motor, a generator, or a motor / generator).
[0002]
[Prior art]
In a conventional rotating electrical machine, a rod member having an inflow passage groove and an outflow passage groove formed on the surface thereof and an outer cylinder having a cooling passage groove formed on the inner peripheral surface thereof are communicated with the inflow passage groove and the cooling passage groove. There is known one in which a single communication path and a second communication path that communicates a cooling path groove and an outflow path groove are incorporated in a rotor shaft that is formed in advance. In this cooling structure, when the refrigerant is supplied from above the outer periphery of the rotor shaft, the refrigerant flows in the inflow passage → first communication passage → cooling passage → second communication passage → outflow passage and falls downward ( For example, see Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2000-295818
[Problems to be solved by the invention]
However, in the conventional cooling structure described above, the shaft structure is complicated, so that the cost increase cannot be avoided. Further, at the time of rotation, pressure loss due to the secondary flow occurs in the passage through which the refrigerant enters and exits the outer peripheral surface, and power loss for supplying the refrigerant increases, resulting in a problem of system efficiency.
[0005]
The present invention has been made paying attention to such conventional problems, and exhibits a high cooling performance with a simple structure, and does not cause a reduction in system efficiency even at a high rotation speed, and is a low-cost rotating electrical machine. It aims to provide a cooling structure.
[0006]
[Means for Solving the Problems]
The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected, it is not limited to this.
[0007]
The present invention includes a rotor (10) that rotates integrally with a rotor shaft that is rotatably supported by a case (40), and a plurality of stator cores that have coils wound around the outer periphery of the rotor. A rotating electrical machine comprising a stator (30), wherein the rotor shaft is inserted into the outer cylinder portion (12) for fixing a rotor core, and the inner shaft is rotatably supported by the case. A gap passage (12b) formed between the outer tube portion and the inner shaft portion, and a refrigerant introduction hole (11a) formed in the axial direction in the inner shaft portion. The refrigerant passage (11b) communicating with the gap passage (12b) and the outer cylinder portion rotate together with the seal (42) provided in the case to form a refrigerant chamber (41), and the refrigerant introduction hole ( 11a) to the communication passage (11b) and the gap passage (12b) A seal portion that prevents the refrigerant from flowing into the air gap between the rotor core and the stator by allowing the refrigerant flowing out of the rotor shaft to flow into the refrigerant chamber (41). (12c) .
[0008]
[Action / Effect]
According to the present invention, since the refrigerant passage is formed by fitting the outer cylinder portion and the inner shaft portion, the structure is simple. Further, since the refrigerant is supplied from the refrigerant introduction hole formed in the axial direction formed in the inner shaft portion, the refrigerant can be supplied regardless of the rotation of the shaft. Therefore, it is possible to obtain a cooling structure for a rotating electrical machine that does not decrease the system efficiency even at high revolutions and that is low in cost.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.
(First embodiment)
FIG. 1 is a view showing a first embodiment of a rotor (rotor) of a rotating electrical machine according to the present invention, FIG. 1 (A) is a side sectional view, and FIG. FIG. 1C is a cross-sectional view taken along the line CC of FIG.
[0010]
The rotor 10 is a rotor that includes an inner shaft portion 11, an outer cylinder portion 12, and a rotor core 13.
[0011]
The inner shaft portion 11 is rotatably supported by a bearing 20. The inner shaft portion 11 is a hollow shaft having a refrigerant introduction hole 11a formed in the axial direction. In FIG. 1, the refrigerant introduction hole 11 a is formed so as to penetrate the inner shaft portion 11, but is not limited to such a through hole. A communication hole 11 b is formed near the center of the inner shaft portion 11. The communication hole 11b is a hole that communicates the refrigerant introduction hole 11a of the inner shaft portion 11 with the outer peripheral surface. In the present embodiment, four communication holes 11b are formed (FIG. 1C). An insertion cap 11c having a small hole 11d is inserted into one end of the inner shaft portion 11. Since one end of the inner shaft portion 11 is closed by the insertion cap 11c as described above, the refrigerant introduced from the refrigerant introduction hole 11a flows into the communication hole 11b (see FIG. 8). Further, the inner shaft portion 11 has a collar 11e that restricts the movement of the inner shaft portion 11 and the outer cylinder portion 12 in the thrust direction by a projection 11g (see FIG. 6B) formed in accordance with the spline fitting portion. Is attached. A spline 11f is formed on the outer peripheral surface of the thickest portion of the inner shaft portion 11, and this portion is fitted to the outer cylinder portion 12 (FIG. 1C). The spline 11f is formed so as not to overlap the communication hole 11b.
[0012]
The outer cylinder part 12 fits the inner shaft part 11. A spline 12 a is formed on the inner peripheral surface of the outer cylinder portion 12 (FIG. 1C), and the spline 12 a fits the spline 11 f of the inner shaft portion 11.
[0013]
The number of teeth of the spline 12a formed on the outer cylinder portion 12 is larger than the number of teeth of the spline 11f formed on the inner shaft portion 11. Incidentally, in FIG. 1C, there are 36 spline grooves 12a formed in the outer cylinder portion 12, and there are four spline teeth 11f formed in the inner shaft portion 11. For this reason, in the spline groove 12a formed in the outer cylinder part 12, there is a groove 12b into which the spline teeth 11f of the inner shaft part 11 are not inserted. The communication hole 11b formed in the inner shaft portion 11 communicates the refrigerant introduction hole 11a of the inner shaft portion 11 with the groove 12b, and makes the groove 12b a refrigerant passage.
[0014]
Further, seals 12 c are attached to both end portions of the outer cylinder portion 12. The seal 12c prevents the refrigerant from flowing into the air gap between the rotor 10 and the stator 30, as will be described later.
[0015]
The rotor core 13 is fixed to the outer cylinder portion 12. The rotor core 13 is press-fitted with an electromagnetic steel plate 13a, and both ends thereof are fixed with end plates 13b. The end plate 13b is fixed to the outer cylinder portion 12 by welding.
[0016]
2-7 is a figure which shows the manufacturing method of the rotor of this embodiment. In addition, each figure (A) shows a sectional side view, and figure (B) shows the figure seen from the rotating shaft direction.
[0017]
(Figure 2; Spline formation process)
Splines 12 a are formed on the entire inner periphery of the outer cylinder portion 12.
[0018]
(Figure 3; Inner shaft fitting process)
Next, the inner shaft portion 11 in which the refrigerant introduction hole 11 a, the communication hole 11 b and the like are formed is inserted into the outer cylinder portion 12. By doing in this way, the refrigerant introduction hole 11a of the inner shaft part 11 and the spline groove 12a (12b) of the outer cylinder part 12 communicate with each other through the communication hole 11b of the inner shaft part 11.
[0019]
(Fig. 4; Electrical steel sheet mounting process)
Subsequently, the electromagnetic steel plate 13a is press-fitted and fixed to the outer periphery of the outer cylinder portion 12, and an end plate 13b for suppressing the electromagnetic steel plate 13a is press-fitted and fixed by welding. In the present embodiment, the electromagnetic steel sheet 13a is fixed after the inner shaft part 11 is fitted to the outer cylinder part 12, but if there is no risk of impairing the electromagnetic performance, the electromagnetic steel sheet 13a is fixed to the outer cylinder part 12. After fixing etc., you may fit the inner shaft part 11 together. Further, the fixing of the end plate 13b is not limited to welding, and may be a screw type.
[0020]
(Figure 5: Seal installation process)
Next, the seal 12 c is fixed to both end portions of the outer cylinder portion 12. The seal 12c prevents the refrigerant from flowing into the air gap between the rotor 10 and the stator 30 (see FIG. 8). In the present embodiment, the seal 12c is fixed to the outer cylinder portion 12, but the present invention is not limited to this, and may be fixed to the end plate 13b, for example.
[0021]
(Fig. 6; collar mounting process)
Subsequently, the projection 11g of the collar 11e is inserted into the spline fitting portion of the inner shaft portion 11 and fixed. The protrusion 11g restricts the movement of the inner shaft portion 11 and the outer cylinder portion 12 in the thrust direction.
[0022]
(Fig. 7; Bearing mounting process)
Finally, the bearing 20 is fixed to the inner shaft portion 11.
[0023]
FIG. 8 is a view showing a state in which the rotor according to the present embodiment is incorporated in a rotating electrical machine. The arrows in the figure indicate the flow of the refrigerant.
[0024]
The stator 30 is attached to the inner peripheral surface of the case 40, and the rotor 10 is rotatably supported by the bearing 20 inside thereof. Further, the seals 12 c provided at both end portions of the outer cylinder part 12 form a refrigerant chamber 41 together with the seals 42 provided in the case.
[0025]
When the rotating electrical machine is cooled, the refrigerant is introduced from one end (the left end in FIG. 8) of the inner shaft portion 11 of the rotor 10. Then, the refrigerant flows through the refrigerant introduction hole 11a → the communication hole 11b → the spline groove 12b, flows out of the rotor shaft, and flows into the oil pan 43 through the refrigerant chamber 41.
[0026]
Since the refrigerant flows in this way, the rotating electrical machine can be efficiently cooled. Further, since the refrigerant is introduced from the rotor shaft, it can be cooled regardless of the operation of the rotating electrical machine.
[0027]
According to the present embodiment, since the inner shaft portion 11 and the outer cylinder portion 12 have a spline fitting structure, it is possible to transmit a large torque and to manufacture at a low cost.
[0028]
Moreover, since the number of teeth of the spline 12a of the outer cylinder part 12 is made larger than the number of teeth of the spline 11f of the inner shaft part 11, the refrigerant introduced from the inner shaft part 11 is not fitted to the inner shaft spline. It is possible to flow along the spline 12b and cool the rotor. At this time, since the outer cylinder spline 12a exhibits a fin effect, a very large cooling performance can be obtained.
[0029]
Furthermore, since the seals 12c are fixed to both end portions of the outer cylinder portion 12, the refrigerant can be prevented from entering the air gap between the rotor 11 and the stator 30, and the friction can be reduced.
[0030]
Furthermore, since the inner shaft part 11 and the outer cylinder part 12 are fixed through the collar 11e having a projection 11g matched to the spline fitting part and the bearing 20 fixed to the outside thereof, the movement in the thrust direction is suppressed. And no adverse effects such as vibration occur.
[0031]
As described above in detail, according to the present embodiment, it is possible to obtain a cooling structure for a rotating electrical machine that exhibits high cooling performance with a simple structure, does not decrease system efficiency even at high speeds, and is low in cost. Is possible.
[0032]
(Second Embodiment)
FIG. 9 is a view showing a second embodiment of the rotor of the rotating electrical machine according to the present invention, FIG. 9 (A) is a side sectional view, and FIG. 9 (B) is a view seen from the direction of the rotation axis. In addition, the arrow in a figure shows the flow of a refrigerant | coolant.
[0033]
In each embodiment shown below, the same code | symbol is attached | subjected to the part which fulfill | performs the same function as 1st Embodiment mentioned above, and the overlapping description is abbreviate | omitted suitably.
[0034]
In the first embodiment, as described above, the communication hole 11b is provided near the center of the inner shaft portion 11 and both ends of the refrigerant passage formed by the spline groove 12b are opened. The hole 11b is brought closer to one end side (the left end side in FIG. 9A) of the inner shaft portion 11, and the refrigerant passage (the refrigerant passage formed by the spline groove 12b) on the one end side is closed with the collar 11h, and the opposite side Only the end portion (the right end side in FIG. 9A) is opened. At this time, in order to reduce the leakage of the refrigerant, a resin material or the like may be interposed between the collar and the shaft.
[0035]
In this embodiment, as shown in FIG. 9A, the communication hole 11b is formed near the end on the refrigerant inlet side, but may be provided near the end on the opposite side of the refrigerant inlet. . In this case, the communication hole 11b is formed near the end opposite to the refrigerant inlet (the right end side in FIG. 9A), and at the end side, the refrigerant passage (formed by the spline groove 12b). The refrigerant passage) is closed and only the end on the opposite side (the left end side in FIG. 9A) is opened.
[0036]
According to the present embodiment, since the refrigerant flows in one direction through the refrigerant passage, the flow velocity is faster than that in the first embodiment. For this reason, larger cooling performance can be obtained.
[0037]
(Third embodiment)
FIG. 10 is a view showing a third embodiment of the rotor of the rotating electrical machine according to the present invention, FIG. 10 (A) is a side sectional view, and FIG. 10 (B) is a view seen from the direction of the rotation axis.
[0038]
In the present embodiment, the inner shaft portion 11 and the outer cylinder portion 12 are fitted with toothless splines having at least three teeth and intermittently formed teeth. FIG. 10B illustrates a spline having 4 teeth.
[0039]
According to this embodiment, since the refrigerant passage 12b having a large flow path area can be formed, the cooling performance can be further improved. The number of teeth may be appropriately determined in consideration of necessary cooling performance, transmission torque, and the like.
[0040]
(Fourth embodiment)
FIG. 11 is a view showing a fourth embodiment of the rotor of the rotating electrical machine according to the present invention, FIG. 11 (A) is a side sectional view, and FIG. 11 (B) is a view seen from the direction of the rotation axis.
[0041]
In the present embodiment, a key groove is formed in each of the inner shaft portion 11 and the outer cylinder portion 12, and the key 14 is fitted therein. Further, projections 15 were formed at two locations on the inner shaft portion 11.
[0042]
Also according to this embodiment, since the refrigerant passage 12b having a large flow path area can be formed, the cooling performance can be further improved.
[0043]
(Fifth embodiment)
FIG. 12 is a view showing a fifth embodiment of the rotor of the rotating electrical machine according to the present invention, FIG. 12 (A) is a sectional side view, and FIG. 12 (B) is a view seen from the direction of the rotation axis.
[0044]
In the present embodiment, key grooves are formed at three locations of the inner shaft portion 11 and the outer cylinder portion 12, and the key 14 is fitted therein.
[0045]
Also according to this embodiment, since the refrigerant passage 12b having a large flow path area can be formed, the cooling performance can be further improved. The number of keys may be determined as appropriate in consideration of necessary cooling performance, transmission torque, and the like.
[0046]
(Sixth embodiment)
FIG. 13 is a view showing a sixth embodiment of the rotor of the rotating electrical machine according to the present invention, FIG. 13 (A) is a side sectional view, and FIG. 13 (B) is a view seen from the direction of the rotation axis.
[0047]
In the present embodiment, the inner shaft portion 11 and the outer tube portion 12 are formed in such a manner that a key groove is formed only near the end portions of the inner shaft portion 11 and the outer tube portion 12 and the key 14 is fitted therein. This is different from the fifth embodiment in which a key groove is formed over the entire fitting length and the key 14 is fitted.
[0048]
Also according to this embodiment, since the refrigerant passage 12b having a large flow path area can be formed, the cooling performance can be further improved. Moreover, since the key 14 is small, weight reduction can be achieved. The number of keys may be determined as appropriate in consideration of necessary cooling performance, transmission torque, and the like.
[0049]
The present invention is not limited to the embodiment described above, and various modifications and changes can be made within the scope of the technical idea, and it is obvious that these are equivalent to the present invention.
[0050]
For example, in the third to sixth embodiments, the position of the communication hole 11b may be changed as in the second embodiment.
[0051]
Also, when using a spline (first to third embodiments) or when using a key only in one place (fourth embodiment), the positions of the spline and key are limited as in the sixth embodiment. You may make it.
[Brief description of the drawings]
FIG. 1 is a diagram showing a first embodiment of a rotor of a rotating electrical machine according to the present invention.
FIG. 2 is a diagram showing a rotor manufacturing method (spline forming step) of the present embodiment.
FIG. 3 is a diagram showing a rotor manufacturing method (inner shaft portion fitting step) according to the present embodiment.
FIG. 4 is a diagram showing a rotor manufacturing method (magnetic steel plate mounting step) according to the present embodiment.
FIG. 5 is a diagram showing a rotor manufacturing method (seal mounting step) according to the present embodiment.
FIG. 6 is a diagram showing a rotor manufacturing method (collar mounting step) according to the present embodiment.
FIG. 7 is a diagram showing a rotor manufacturing method (bearing mounting step) according to the present embodiment.
FIG. 8 is a view showing a state in which the rotor according to the present embodiment is incorporated in a rotating electrical machine.
FIG. 9 is a diagram showing a second embodiment of the rotor of the rotating electrical machine according to the present invention.
FIG. 10 is a view showing a third embodiment of the rotor of the rotating electrical machine according to the present invention.
FIG. 11 is a view showing a fourth embodiment of the rotor of the rotating electrical machine according to the present invention.
FIG. 12 is a view showing a fifth embodiment of the rotor of the rotating electrical machine according to the present invention.
FIG. 13 is a diagram showing a sixth embodiment of the rotor of the rotating electrical machine according to the present invention.
[Explanation of symbols]
10 Rotor 11 Inner shaft portion 11a Refrigerant introduction hole 11b Communication hole (communication path)
11f Spline 12 Outer cylinder portion 12a Spline 12b Spline groove (refrigerant passage; gap passage)
12c Seal 13 Rotor core 13a Magnetic steel plate 13b End plate 14 Key 20 Bearing 30 Stator 40 Case

Claims (9)

A rotor that rotates integrally with a rotor shaft that is rotatably supported by the case;
A stator having a plurality of stator cores around which coils are wound in the circumferential direction on the outer peripheral side of the rotor;
A rotating electric machine comprising:
The rotor shaft is
A hollow outer cylinder for fixing the rotor core;
An inner shaft portion inserted into the outer cylinder portion and rotatably supported by the case;
Have
A gap passage formed between the outer tube portion and the inner shaft portion;
A refrigerant introduction hole formed in the axial direction in the inner shaft portion, and a communication passage communicating the gap passage;
The refrigerant that rotates together with the outer cylinder portion forms a refrigerant chamber together with a seal provided on the case, and the refrigerant that flows out of the rotor shaft through the communication passage and the gap passage from the refrigerant introduction hole enters the refrigerant chamber. A seal portion that prevents the refrigerant from flowing into the air gap between the rotor core and the stator,
A cooling structure for a rotating electrical machine comprising: A spline having the number of teeth m formed on the entire inner circumference of the outer cylinder portion;
A spline having the number of teeth n (where n <m) is formed on the outer peripheral surface of the inner shaft portion and can be fitted to the spline of the outer cylinder portion;
Have
The gap passage is a spline groove in which the spline teeth of the inner shaft portion are not fitted among the spline grooves formed in the outer cylinder portion.
The cooling structure for a rotating electric machine according to claim 1. A spline having the number of teeth n intermittently formed at a predetermined position on the inner peripheral surface of the outer cylindrical portion;
A spline having n teeth that is formed on the outer peripheral surface of the inner shaft portion and can be fitted to the spline of the outer cylinder portion;
Have
The gap passage is a gap space portion between the outer tube portion and the inner shaft portion where the spline is not formed.
The cooling structure for a rotating electric machine according to claim 1. The number of teeth n of the spline is at least 3 or more.
The cooling structure for a rotating electrical machine according to claim 2 or 3, wherein the cooling structure is used. The outer diameter of the inner shaft portion is smaller than the inner diameter of the outer cylinder portion,
The gap passage is a gap space portion formed by the difference in diameter,
A keyway is formed in the outer cylinder part and the inner shaft part,
A key that fits into the keyway,
The cooling structure for a rotating electric machine according to claim 1. The spline is formed over the entire length of the fitting portion between the outer tube portion and the inner shaft portion.
The cooling structure for a rotating electric machine according to any one of claims 2 to 4 , wherein the cooling structure is provided. The spline is formed near both end portions of a fitting portion between the outer tube portion and the inner shaft portion.
The cooling structure for a rotating electric machine according to any one of claims 2 to 4 , wherein the cooling structure is provided. The communication path is formed so as to communicate with the vicinity of the center of the gap path.
The cooling structure for a rotating electric machine according to claim 1. The communication path is formed so as to communicate near one end of the gap path,
The gap passage is closed at the end on the one end side,
The cooling structure for a rotating electric machine according to claim 1.

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