JPH08205474A - Liquid-cooled electric rotating machine - Google Patents

Abstract

PURPOSE: To obtain a liquid-cooled electric rotating machine having low heat transmission resistance and the heat can be discharged easily while facilitating the manufacture and enhancing the solidity. CONSTITUTION: A tubular cooling path 6 for circulating the cooling liquid is provided in the circumferential wall part 10 of an enclosed tubular housing 1 and a spiral straightener 9 is disposed in the cooling path 6. The cooling liquid introduced to a predetermined position of the cooling path 6, preferably at one end thereof in the axial direction, is guided by the straightener 9 to flow spirally at high speed. Consequently, the heat transmission resistance from the housing 1 to the cooling liquid is decreased and since a water pool is prevented from being formed in the cooling path 6, heated cooling liquid is not pooled and the heat is discharged well. Furthermore, since the straightener 9 may be inserted simply into the tubular cooling path 6 in the axial direction, manufacture and assembling work are facilitated and the housing 1 can be made solid because double cylindrical structure is not required.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid-cooled rotary electric machine.

[0002]

2. Description of the Related Art A liquid-cooled rotary electric machine that is cooled by a cooling liquid is known. For example, an outer frame is coaxially fitted to an inner frame to form a double frame structure, and both are sealed by welding to liquid-cool inside. There has been one that constitutes a passage and causes a cooling liquid to flow through this liquid cooling passage.

Further, Japanese Patent Laid-Open No. 06-070507 discloses
We propose a structure in which a pipe for circulating cooling water is wrapped around the peripheral wall of the frame.

[0004]

However, in the former liquid-cooled rotary electric machine described above, since the outer frame and the inner frame form the cylindrical cooling passage, the flow of the cooling liquid in the cooling passage is weak, In addition to the increase in heat transfer resistance to the cooling liquid, there is a problem that it is difficult to discharge the heat absorbed by the cooling liquid to the outside. That is, it is not easy to form a smooth flow of the cooling liquid inside the liquid cooling passage, and so-called dead water is generated, so that the cooling effect is likely to deteriorate.

In order to solve this problem, a spiral fin is projected on the inner peripheral surface of the outer frame or the outer peripheral surface of the inner frame to generate a spiral flow of the cooling liquid inside the cylindrical cooling passage. For example, it is possible to expect a reduction in the heat transfer resistance and an increase in the heat discharge while suppressing an increase in fluid loss. However, since the outer frame and the inner frame are formed by casting, in order to mold such a spiral fin, a very complicated split mold has to be used, and a great extension of the process is inevitable. Become.

Further, even if such a spiral fin is formed on either the outer frame or the inner frame by using a complicated split mold, the frame (hereinafter, also referred to as a housing) of the rotary electric machine has two members. Since it is configured by coaxial fitting, strength and vibration resistance are significantly deteriorated. On the other hand, the above-mentioned idea of spirally winding the pipe has a problem that the heat transfer resistance is apt to increase and the winding step is troublesome.

The present invention has been made in view of the above problems, and provides a liquid-cooled rotary electric machine that has a small heat transfer resistance and can easily dissipate heat, and that is easy to manufacture and excellent in robustness. Is the purpose.

[0008]

The first structure of the present invention is as follows.
A closed cylindrical housing, a rotor rotatably supported on the end surface of the housing, and a stator fixed to the inner peripheral surface of the housing are provided, and a peripheral wall portion of the housing has a cylindrical shape for circulating a cooling liquid. A liquid-cooled rotary electric machine having a cooling passage, comprising a straightening plate having a predetermined width and a predetermined thickness, which is formed in a spiral shape and is housed in the cooling passage. .

A second structure of the present invention is further characterized in that, in the first structure, the pitches of the straightening vanes are made unequal.

[0010]

In the first structure of the present invention, the cylindrical cooling passage for circulating the cooling liquid is formed in the peripheral wall portion of the closed cylindrical housing, and the spiral passage straightening plate is provided in the cooling passage. Is arranged. With this configuration, the cooling liquid introduced at the predetermined position of the cooling passage, preferably one end portion in the axial direction, is guided by the flow straightening plate and flows in a spiral at a high speed,
As a result, the heat transfer resistance from the housing to the cooling liquid is reduced, and it is difficult to form a dead water space in the cooling passage, and the high temperature cooling liquid is less likely to stay in the cooling passage. Further, the flow straightening plate may be simply inserted in the cylindrical cooling passage of the housing in the axial direction, is easy to manufacture and assemble, and the housing does not need to have a double cylindrical shape, so that it is robust. Further, the sealing structure is also easy because an O-ring or the like may be provided when the end frame is fixed to the end surface of the peripheral wall portion of the housing used in a normal motor.

In the second structure of the present invention, since the pitch of the rectifying plates is further unequal in the first structure, for example, a high heat generating portion such as the outer peripheral side of the coil end portion of the stator coil inside the housing is formed. The space distribution of the cooling performance can be set to a desired pattern by narrowing the pitch in the vicinity to increase the flow velocity of the cooling liquid and preferentially cooling the places where cooling is particularly important.

[0012]

【Example】

(Embodiment 1) One embodiment of the liquid-cooled rotary electric machine of the present invention is shown in FIG.
Will be described with reference to. In this liquid-cooled rotary electric machine, a front housing 1 and a rear housing 2 are fastened to each other to form a housing in the present invention. A rotor core 4 around which a rotor coil 40 is wound is fixed to a rotary shaft 3 which is rotatably supported by a front housing 1 and a rear housing 2 via bearings 30, respectively.
On the other hand, the stator core 5 around which the stator coil 50 is wound is fixed to the inner peripheral surface of the front housing 1,
The inner peripheral surface of the stator core 5 faces the outer peripheral surface of the rotor core 4 via a minute gap.

The front housing 1 is made of an aluminum die cast product, and a cylindrical cooling passage 6 is formed in a peripheral wall portion 10 of the front housing 1. The cylindrical cooling passage 6 opens at an end surface 11 on the rear side of the front housing 1, and a flange portion 12 is provided at the open end of the front housing 1 so as to project radially outward. The rear housing 2 is also made of an aluminum die-cast product, and the outer peripheral end surface of the rear housing 2 is fastened with fastening bolts 8 while sandwiching the O-ring 7a in a state of being in close contact with the flange portion 12. In addition, the outer peripheral portion of the rear housing 2 is a cylindrical portion 21 that fits in the peripheral wall portion 10 with the O-ring 7b sandwiched in the vicinity of the opening of the front housing 1.
The O-rings 7a and 7b seal the cooling passage 6.

The feature of the present embodiment is that the cylindrical cooling passage 6 accommodates the spiral flow straightening plate 9 therein. Hereinafter, the spiral current plate 9 will be described with reference to FIGS. 2 and 3. The spiral rectifying plate 9 is formed by spirally bending a strip plate-shaped copper plate having a predetermined thickness and a predetermined width slightly smaller than the radial width of the cylindrical cooling passage 6, and its axial length is It is formed to be slightly longer than the axial length of the cylindrical cooling passage 6.

Therefore, when the spiral flow straightening plate 9 is pushed into the cylindrical cooling passage 6, the tip of the spiral flow straightening plate 9 slightly projects from the opening, but this projecting portion is the rear housing (that is, the end). By pushing in with the frame 2, the spiral rectifying plate 9 is compressed in the axial direction to some extent, and the repulsion is used to prevent undesired chattering of the spiral rectifying plate 9.

The peripheral wall portion 10 of the front housing 1
An inlet passage (not shown) and an outlet passage (not shown) for the cooling liquid are formed therein. This inlet passage communicating with the front end of the cylindrical cooling passage 6 is connected to the outlet of an external cooling pump (not shown) by a pipe line (not shown), while communicating with the rear end of the cylindrical cooling passage 6. This outlet passage is connected to the inlet of the cooling pump through a conduit and a cooler (not shown). Note that this cooling system may be provided separately, and for example, the circulating fluid of the engine or the air conditioning system may be branched and used.

The operation of this device will be described below. First, the cooling pump is driven by a motor or an engine to circulate the cooling liquid. Of course, this cooling pump can be driven by the liquid-cooled rotary electric machine itself of FIG. When the liquid-cooled rotary electric machine is operated in this state, the heat generated inside the housing is transmitted to the front housing 1, and is transmitted to the cooling fluid flowing in the axial direction while rotating in the cylindrical cooling passage 6 from the front housing 1 to the outside. Be discharged well.

In this embodiment, as shown in FIG. 3, a predetermined gap d is secured between the inner diameter of the spiral flow straightening plate 9 and the inner diameter of the cylindrical cooling passage 6. With this configuration, the liquid cooling type rotary electric machine can be tilted and the cooling liquid can be discharged from the cooling liquid inlet passage (not shown) or the outlet passage (not shown) without driving the cooling pump. The cooling liquid can be easily replaced. (Embodiment 2) Another embodiment will be described.

In this embodiment, the pitch of the spiral rectifying plate 9 is changed by a predetermined pattern. More specifically, the axial temperature of the peripheral wall portion 10 of the front housing 1 is different. For example, the temperature at the central portion in the axial direction may be higher than that at both ends. To address this issue,
In the present embodiment, the pitch of the spiral rectifying plates 9 at both axial ends of the cylindrical cooling passage 6 adjacent to both coil ends of the stator coil 50 is set to be spiral at the axial central portion of the cylindrical cooling passage 6. The pitch is designed to be larger than the pitch of the straightening vanes 9. This way, it ’s very easy
It is possible to improve the flow velocity of the cooling liquid in the central portion of the cylindrical cooling passage 6 in the axial direction, thereby relatively improving the cooling effect in these portions. Further, since the pitch is partially reduced, the increase in pressure loss can be reduced as compared with the case where the pitch is reduced overall.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a liquid-cooled rotary electric machine according to the present invention.

FIG. 2 is a perspective view of a spiral current plate 9.

FIG. 3 is a partially enlarged sectional view of a cylindrical cooling passage 6.

[Explanation of symbols]

1 is a front housing (housing), 2 is a rear housing (housing), 3 is a rotating shaft, 4 is a rotor core,
Reference numeral 5 is a stator core, 6 is a cylindrical cooling passage, 9 is a spiral current plate, and 50 is a stator coil.

Claims (2)

[Claims] 1. A hermetically sealed cylindrical housing, a rotor rotatably supported on an end surface of the housing, and a stator fixed to an inner peripheral surface of the housing, wherein a peripheral wall portion of the housing is provided with a cooling liquid. A liquid-cooled rotary electric machine having a cylindrical cooling passage for circulation, characterized by comprising a straightening plate having a predetermined width and a predetermined thickness and formed in a spiral shape and accommodated in the cooling passage. Rotary electric machine. 2. The liquid-cooled rotary electric machine according to claim 1, wherein the rectifying plates have unequal pitches.