JP2019161741A - Cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device having a simpler structure than a conventional device and capable of improving a cooling performance by increasing a refrigerant wetting area. A cooling device that injects a refrigerant toward a cooling target to cool the cooling target is provided. A pipe main body 10a that includes a refrigerant passage 10b through which the refrigerant flows and is provided at a position where the refrigerant can be jetted toward the coil end 6b to be cooled, and a pipe that is bored in the pipe main body 10a and provided at a position facing the cooling target. And an injection hole 11 for injecting a refrigerant toward a cooling target, and the injection hole 11 is formed in a slit shape. Since the injected refrigerant spreads in a fan shape in the direction of the long side of the slit, the refrigerant wetting area can be increased as compared with the case where the injection hole is circular. [Selection] Fig. 3

Description

  The present invention relates to a cooling device that cools a cooling target by injecting a refrigerant toward a cooling target (for example, a member constituting a rotating electrical machine).

  Patent Document 1 is a cooling pipe provided in the direction of the rotation axis of a motor above a stator of a rotating electrical machine, and the cooling pipe is provided with a plurality of injection holes capable of injecting the refrigerant at various angles. Disclosed is a cooling device for spraying to the end. According to this device, the refrigerant can be injected over a wide range of the coil end.

  In Patent Document 2, a pipe member extending in the circumferential direction of a stator core of a rotating electrical machine is provided with two or more refrigerant injection portions, and the refrigerant is injected toward both end portions (coil ends) of a coil wound around the stator core. A cooling device for a rotating electrical machine is disclosed. According to this device, the circumferential direction of the coil end can be uniformly cooled.

Japanese Patent Laid-Open No. 2006-134972 JP-A-2006-129438

  The above-described conventional cooling device increases the number of installed jetting parts (injection holes) for jetting the refrigerant, thereby increasing the area of the refrigerant that is in contact with the refrigerant on the surface of the cooling target and increasing the cooling capacity. However, there is room for improvement in terms of further simplifying the structure and reducing costs.

  The present invention has been made paying attention to this point, and provides a cooling device capable of increasing the refrigerant wetting area and improving the cooling capacity by using a simpler structure as compared with the conventional device. Objective.

  In order to achieve the above object, the invention according to claim 1 is directed to a refrigerant passage (10b) through which the refrigerant flows in a cooling device that injects the refrigerant toward the cooling object (6) and cools the cooling object (6). And a passage forming member (10a) provided at a position where the refrigerant can be injected toward the cooling target (6), and the passage forming member (10a), It is an injection hole provided at a position facing it, and includes an injection hole (11) for injecting the refrigerant toward the cooling target (6), and the injection hole (11) is formed in a slit shape. It is characterized by.

  According to this configuration, the refrigerant spreads in a fan shape in the direction in which the long side of the slit shape (the short side is a very short rectangle compared to the long side) extends, so the refrigerant wetting area is increased with a simple configuration. Therefore, the cooling capacity can be improved as compared with the conventional circular injection hole. In the case of the conventional circular injection hole, if the flow rate of the refrigerant is increased to increase the cooling capacity, a part of the refrigerant will bounce off the object to be cooled. Although it is small, since it has a slit shape, the injection pressure is dispersed and rebound hardly occurs, so that a high cooling capacity commensurate with an increase in flow rate can be obtained.

The invention according to claim 2 is the cooling device according to claim 1, wherein the long side of the slit shape extends in a direction perpendicular to the direction in which the passage forming member (10a) extends. .
According to this configuration, since the refrigerant spreads in a fan shape in a direction perpendicular to the direction in which the passage forming member extends, the refrigerant wetting area in the spread direction can be increased.

  A third aspect of the present invention is the cooling device according to the first or second aspect, wherein the slit-shaped long side and the short side length (LS, WS) are determined by the injection hole (11) and the cooling target. It is set based on a distance (H) to (6) and a desirable injection angle range (IR) of the refrigerant.

  When the flow rate of the refrigerant is the same, if the short side of the slit shape is too long, the spread of the refrigerant tends to be small, and the range in which the actually injected refrigerant reaches is the distance between the injection hole and the object to be cooled ( Target distance) and the injection angle range of the refrigerant, so that the length of the long side and the short side corresponding to the required flow rate of the refrigerant is set based on the target distance and the desired injection angle range. It is possible to secure a desirable refrigerant wetting area.

According to a fourth aspect of the present invention, in the cooling device according to any one of the first to third aspects, the cooling target is a stator (6) constituting the rotating electrical machine (1), and the rotating electrical machine ( 1) includes a rotating shaft (3) and a rotor (7) fixed to the rotating shaft (3) inside the stator (6) and rotated by magnetic flux generated by the stator (6). The forming member (10a) is provided so as to extend in the axial direction of the rotating shaft (3).
According to this configuration, the cooling capacity of the stator of the rotating electrical machine can be increased with a simple configuration.

It is sectional drawing which shows the structure of the rotary electric machine to which the cooling device concerning one Embodiment of this invention is applied. It is a figure for demonstrating the state which looked at the refrigerant | coolant injection pipe (10) and coil end (6b) shown in FIG. 1 from the side. It is a figure for demonstrating the structure of the refrigerant | coolant injection pipe (10) shown in FIG. 1, and a refrigerant | coolant injection hole (11). It is a figure for demonstrating the state of the injected cooling oil. It is a figure which shows the modification regarding the peripheral wall (12) of a refrigerant | coolant injection hole (11). It is a figure which shows the modification regarding arrangement | positioning of a refrigerant | coolant injection pipe. It is a figure which shows the modification applicable instead of a refrigerant | coolant injection pipe.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view showing a configuration of a rotating electrical machine to which a cooling device according to an embodiment of the present invention is applied. The rotating electrical machine 1 is fixed to a casing 2 and generates a magnetic flux. A rotating shaft 3 rotatably supported via 4 and 5, a columnar rotor 7 fixed to the rotating shaft 3 inside the stator 6 and rotated by magnetic flux generated by the stator 6, and above the stator 6. And a refrigerant injection pipe 10 for injecting cooling oil as a refrigerant. Cooling oil is supplied to the refrigerant injection pipe 10 via a refrigerant passage 9 provided in the casing 2. Cooling oil is supplied to the refrigerant passage 9 via an oil pump and an oil passage (not shown). The oil pump is driven using a part of the driving torque obtained by the rotation of the rotating shaft 3, for example.

  The stator 6 includes a stator core 6a and a stator coil 6b wound around the stator core 6a. The portions located at both ends of the stator 6 in the axial direction are usually called “coil ends”. End 6b ".

  The refrigerant injection pipe 10 is provided so as to extend parallel to the rotation shaft 3 (extend in the axial direction), and pressurized cooling oil is supplied to the refrigerant injection pipe 10 via the refrigerant passage 9, and the coil end 6b. Cooling oil is injected toward the coil end 6b from the two refrigerant injection holes 11 provided above. The refrigerant injection pipe 10 and the refrigerant injection hole 11 constitute the cooling device of the present invention.

  FIG. 2 is a view for explaining a state in which the refrigerant injection pipe 10 and the coil end 6 b are viewed from the side, and the stator 6 is fixed to the casing 2 via an attachment member 15. The angle range IR shown in this figure schematically shows the injection angle range of the cooling oil injected from the refrigerant injection hole 11, and the cooling oil spreads in a fan shape and is injected toward the coil end 6b. The injected cooling oil flows down along the outer peripheral surface of the coil end 6b as shown by a thick broken line.

  3A and 3B are diagrams for explaining the structure of the refrigerant injection pipe 10 and the refrigerant injection hole 11. FIG. 3A is a view of the refrigerant injection pipe 10 viewed from below, and FIG. FIG. 2C is a cross-sectional view of the refrigerant injection hole 11 of the refrigerant injection pipe 10.

  The refrigerant injection pipe 10 includes a pipe body 10a, a refrigerant passage 10b through which cooling oil flows, and two refrigerant injection holes 11 that inject the cooling oil from the refrigerant passage 10b toward the outside. The refrigerant injection hole 11 is formed in a slit shape in which the length of the long side is LS and the length of the short side (slit width) is WS, and the long side of the slit shape extends in the direction in which the refrigerant injection pipe 10 extends (rotation axis direction). ) At a position facing the coil end 6b. In the example shown in FIG. 3, the peripheral wall 12 from the refrigerant injection hole 11 as the portion where the refrigerant passage 10 b is exposed to the outer peripheral portion of the pipe body 10 a has a constant cross-sectional area defined by the peripheral wall 12. It is formed to become. The cooling oil is injected from the refrigerant injection hole 11 toward the coil end 6b. The pipe body 10a is configured using, for example, stainless steel.

  In FIG. 2, the refrigerant injection angle range IR is indicated by thin solid lines L1 and L2, and the solid lines L1 and L2 correspond to the tangent lines on the outer periphery of the coil end 6b. The range in which the refrigerant reaches is determined depending on the distance H (target distance) between the refrigerant injection hole 11 and the coil end 6b and the injection angle range IR of the refrigerant when the flow rate of the refrigerant is the same. By setting the side length LS and the slit width WS based on the target distance H and the desired injection angle range IR corresponding to the required flow rate of the refrigerant, it is possible to ensure a desirable refrigerant wetting area. In the embodiment shown in FIGS. 1 and 2, when the outer diameter DP of the refrigerant injection pipe 10 is about 12 mm, the inner diameter DC of the refrigerant injection pipe 10 is set to about 6 mm, and the length of the long side of the slit shape is set. LS is set to about 5 mm, and the slit width WS is set to about 0.35 mm. It has been confirmed that if the slit width WS is too large, the spread of the refrigerant tends to be small, and this point is also taken into consideration when setting the slit width WS.

  4A and 4B are views for explaining the state of the injected cooling oil. FIG. 4A corresponds to the refrigerant injection pipe 10 of the present embodiment, and FIG. 4B shows a conventional circular refrigerant injection. It corresponds to the refrigerant injection pipe 10X having holes.

  In the case of a circular refrigerant injection hole, a cylindrical cooling oil flow having substantially the same diameter as the injection hole is injected, whereas according to the refrigerant injection pipe 10 of the present embodiment, the slit-shaped long side has a long side. A planar cooling oil flow spreading in a fan shape in the extending direction is jetted. Therefore, the area of the region where the injected cooling oil reaches directly increases, and further, as shown by the thick broken line in FIG. 2, the cooling oil spreads and flows down the outer peripheral surface of the coil end 6b to be cooled. The wetting area increases, and the decrease in cooling capacity is reduced even when it flows down. In the case of a circular injection hole, if the flow rate of the refrigerant is increased to increase the cooling capacity, a part of the refrigerant will bounce off the object to be cooled, so the effect of increasing the cooling capacity against the increase in the flow rate is small. Since the injection pressure is dispersed and the rebound hardly occurs by adopting the slit shape, a high cooling capacity commensurate with the increase in the flow rate can be obtained.

The ability to cool the object to be cooled can be represented by the reciprocal of the thermal resistance Rth defined by the following equation.
Rth = 1 / (oil x Awet)
Here, foil is the heat transfer coefficient of the cooling oil, and Awet is the refrigerant wetting area.
Therefore, by increasing the refrigerant wetting area Awet, the thermal resistance Rth can be reduced and the cooling capacity can be increased.

  Since the coolant injection hole 11 is slit-shaped as described above, the cooling oil is sprayed in a fan shape in the direction in which the long side of the slit shape extends, so that it is possible to increase the coolant wetting area with a simple configuration. Thus, the cooling capacity can be improved as compared with the conventional circular coolant injection hole.

  The present invention is not limited to the embodiment described above, and various modifications can be made. For example, the peripheral wall 12 of the refrigerant injection hole 11 is not limited to that shown in FIG. 3 and may be formed as shown in FIG. 5A or 5B, for example. In the modification shown in FIG. 5A, the peripheral wall 12a is formed so that the cross-sectional area of the passage defined by the peripheral wall 12a gradually increases. In the modification shown in FIG. 5B, the peripheral wall 12b is formed to extend in the horizontal direction. According to this modification, the slit-shaped refrigerant injection holes 11 can be easily formed by cutting the pipe body 10a in the horizontal direction.

  In the above-described embodiment, the single refrigerant injection pipe 10 is provided above the stator 6. However, for example, as shown in FIG. 6, two refrigerant injection pipes 10A and 10B may be provided. Thus, the cooling capacity can be further increased by increasing the number of refrigerant injection pipes.

  Further, as shown in FIG. 7, the refrigerant passage 110 may be configured by the inner wall surface of the casing 102 and the passage cover 113, and the refrigerant injection hole 111 may be provided in the passage cover 113. In this modification, the casing 102 and the passage cover 113 correspond to a passage forming member.

  In the above-described embodiment, the refrigerant injection pipe 10 is provided so as to extend in the direction of the rotating shaft 3 of the rotating electrical machine 1, but when the axial dimension of the rotating electrical machine is small as shown in Patent Document 2 above. The refrigerant injection pipe 10 may be provided so as to extend linearly in a direction along the outer periphery of the stator (coil end 6b) or in a direction perpendicular to the rotation shaft 3.

  Further, the cooling target of the cooling device according to the present invention is not limited to the coil end 6b of the stator 6, but may be the entire stator 6. Furthermore, the present invention is, for example, a cooling device that cools a workpiece to be heated when performing machining such as cutting, or a cooling device that cools a CPU (central processing unit) applied to an electronic computer or a control device. It is applicable to. The refrigerant is not limited to cooling oil but may be cooling water.

DESCRIPTION OF SYMBOLS 1 Rotating electrical machine 2 Casing 3 Rotating shaft 6 Stator 6b Stator coil (coil end)
7 Rotor 10 Refrigerant injection pipe (cooling device)
10a Pipe body (passage forming member)
10b Refrigerant passage 11 Refrigerant injection hole

Claims (4)

In the cooling device for injecting the refrigerant toward the cooling target and cooling the cooling target,
A passage forming member that includes a refrigerant passage through which the refrigerant flows, and is provided at a position where the refrigerant can be injected toward the cooling target;
An injection hole formed in the passage forming member at a position facing the object to be cooled, and an injection hole for injecting the refrigerant toward the object to be cooled,
The cooling device according to claim 1, wherein the injection hole is formed in a slit shape.   The cooling device according to claim 1, wherein the long side of the slit shape extends in a direction perpendicular to a direction in which the passage forming member extends.   The lengths of the long side and the short side of the slit shape are set based on a distance between the injection hole and the object to be cooled and a desirable injection angle range of the refrigerant. The cooling device according to 1.   The object to be cooled is a stator constituting a rotating electrical machine, and the rotating electrical machine includes a rotating shaft, and a rotor fixed to the rotating shaft inside the stator and rotated by magnetic flux generated by the stator, and the passage The cooling device according to any one of claims 1 to 3, wherein the forming member is provided so as to extend in an axial direction of the rotating shaft.

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