JPS582129Y2 - Cooling structure of submersible rotating electric machine - Google Patents

Description

[Detailed description of the invention] The present invention relates to a cooling structure for a submersible rotating electric machine in which a part of pumped water is used to cool the stator core of the rotating electric machine, and the cooling water drainage pipe is formed integrally with the frame. At the same time, spiral fins are also formed integrally with the frame to improve the cooling effect without hindering the circulation of cooling water, reducing the overall bulk of the aircraft while improving the cooling effect. be.

When pumping water using a submersible rotating electric machine, when the rotating electric machine part of the submersible rotating electric machine is submerged in water, heat dissipation is good and the temperature rise is small even if it is continuously operated, but as a result of pumping water, the water level When the rotating electric machine part is exposed to the air due to the lowering of the temperature, the temperature rise reaches its limit after a short period of about 30 minutes of operation under these conditions.

In order to enable continuous operation even under such conditions, it is necessary to cool down the rotating electric machine in some way.

One of the conventional technologies that meets this demand is a method in which the frame of the rotating electric machine is surrounded by a cooling jacket, and a part of the water pumped by the pump is supplied between the frame and the cooling jacket to perform the specified cooling. Something exists.

Currently, the following two types of submersible rotating electric machines of this type are commonly used.

One of them, as shown in FIG.
The outer peripheral surface of this frame 3 and the cooling jacket 4
By pumping the water in the pump casing 5 through the water supply vibro and the water supply hole 7a, cooling water is filled and circulated in the space between the frame 3 and the inner peripheral surface of the pump casing 5. After heat exchange, the water is discharged through the drain port 4a.

As a result, the cooling fins 8 protrude and occupy the space formed by the frame 3 and the cooling jacket 4. Therefore, the drain hole 4a is bored in the upper part of the cooling jacket 4, and the drain hole 4a is formed in the upper part of the cooling jacket 4. A drain pipe 9 that leads the cooling water to the outside is connected.

Furthermore, the rotating electrical machine section 1 of this example is composed of an induction motor, and includes a rotating shaft 10 that also functions as a pump shaft, and this rotating shaft 1o.
The rotor core 11 is fixed to the rotor core 11.
the stator core 2 surrounding the stator core 2 with a slight gap;
From the frame 3 to which this stator core 2 is fixed, the upper bracket 12 that closes the upper end of this frame 3, and the lower bracket 7 that also closes the lower end of the frame 3 and has the water supply hole 7a drilled therein. Become.

On the other hand, the cooling jacket 4 is closed at its upper end by the disk 13 and at its lower end by the lower bracket 7, respectively.

Further, in FIG. 1, 14 is a cable that supplies power to the rotating electric machine section 1, 15 is a connection bracket that connects the lower bracket 7 and the pump casing 5, and 16 is a pump blade fixed to the lower end of the rotating shaft 10. It is.

Mechanical seals 17 and 18 are interposed at the pump casing 5 side of the connection bracket 15 and at the portions of the lower bracket 7 that face the rotating shaft 10 on the connection bracket 15 side, respectively.

On the other hand, in the other one, as shown in FIG. 2, the shape of the frame 23 of the rotating electrical machine section 21 is different from that in the upper one.

That is, a drain pipe 23a for draining cooling water is integrally formed in a part of the outer peripheral surface of the frame 23, and a cooling jacket 24 is connected to the frame 23 on the outside of this drain pipe 23a.
It surrounds.

At this time, the upper end of the drain pipe 23a opens into a space formed by the outer circumferential surface of the frame 23 and the inner circumferential surface of the cooling jacket 24, and the lower end thereof opens to the outside via the drain hole 27b.

In this example, the drain hole 27b is bored in the lower bracket 27 together with the water supply hole 27a.

Since the other parts are the same as those in the previous example, only the corresponding instruction numbers are given in FIG. 2, and redundant explanation will be omitted.

In this example, the cooling water supplied to the space formed by the frame 23 and the cooling jacket 24 through the water supply hole 27a is discharged to the outside through the drainage hole 27b after completing a predetermined heat exchange.

By the way, of the two conventional technologies mentioned above, the former requires the drain pipe 9 to be separately attached to the cooling jacket 4, which not only increases the cost but also increases the bulk of the aircraft. It has the disadvantage of becoming.

Also, although the latter can be smaller in bulk than the former, it has the drainage pipe 23a, so the cooling fins 8 that the former has
Since it is not possible to provide a

That is, in the prior art, it is impossible to simultaneously satisfy the requirements of reducing the bulk of the aircraft to reduce costs and improving the cooling efficiency.

Therefore, in view of the above-mentioned drawbacks of the prior art, the present invention aims to provide a submersible rotating electrical machine that can reduce the bulk of the machine body and reduce costs, as well as improve cooling efficiency.
The structure is such that a space formed between an inner circumferential surface of a cooling jacket surrounding a frame of a rotating electric machine part and an outer circumferential surface of the frame is filled with cooling water pumped from inside a pump casing through a water supply hole. In a submersible rotating electric machine in which the frame is cooled by circulation, the frame has an elliptical outer shape in a cross section and a circular inner shape in contact with the stator core. A drainage pipe, which is an arcuate long hole extending in the axial direction of the frame, is provided in the thick wall part in the long axis direction of the ellipse formed between the outer peripheral surface and the inner peripheral surface of the frame. The upper end of this drainage pipe is opened into the space formed by the cooling jacket and the frame, and the lower end thereof is opened to the outside through a drainage hole, and spiral cooling fins are provided on the outer peripheral surface of the frame. It is characterized by

Embodiments of the present invention will be described in detail below with reference to the drawings.

Note that parts that are the same as those in the prior art are given the same numbers and redundant explanations will be omitted.

As shown in FIGS. 3A and 3S, the frame 33 of the rotating electrical machine section 31 has an elliptical outer shape in its cross section (see FIG. The shape is circular.

Therefore, there is a thick portion 33c in the long axis direction of the ellipse.

33d are formed respectively, and drainage holes 37b.

Drain pipe 33 that discharges cooling water to the outside via 37c
Reference characters a and 33b are elongated holes having an arcuate cross section that are integrally formed in the thick portions 33c and 33d in the axial direction of the frame 33.

Further, spiral cooling fins 3 are provided on the outer periphery of this frame 33.
8 is integrally formed.

A cooling jacket 34 surrounds the frame 33 outside the cooling fins 38.

Therefore, the outer peripheral surface of the frame 33 and the cooling jacket 34
A space is formed between the inner circumferential surface of the pump casing 5 and the cooling water that rises from inside the pump casing 5 via the water supply vibro flows into the space via the water supply hole 3γa and drains into the drain pipe 33.
It is discharged to the outside from the drain holes 31b and 3γC via the drain holes 31b and 33b.

That is, the drain pipe 33a. The upper end of 33b opens into the space, and the lower end opens to the outside of the space through drainage holes 37 b p 37 c.

In addition, the water supply hole 3γa and the drainage hole 37 b v 37
c is a hole formed in the lower bracket 37.

At this time, the drain pipes 33a and 33b are formed so that the width F along the short axis of the ellipse is large, and the width G along the long axis of the ellipse (see Figure 3) is small.

As a result, the maximum width H of the frame 33 can be reduced, and in turn, the inner diameter of the cooling jacket 34 can be reduced.

In such a submersible rotating electric machine, the cooling water supplied from inside the pump casing 5 into the cooling jacket 34 through the water supply vibro and the water supply hole 37a rises along the cooling fins 38 and exchanges heat with the frame 33, thereby reducing the cooling water. The frame 33 is cooled and reaches the upper ends of the drain pipes 33a, 33b, descends inside the drain pipes 33a, 33b, and is discharged to the outside through the drain holes 37b, 37c.

At this time, the flow passage cross-sectional area I in the cooling jacket 34 is given by the following equation.

■1-2(Dl-C1)P However, + CI- Outer diameter D1 of frame 33 - Inner diameter P of cooling jacket 34 - Pitch of cooling fins 38 In contrast, flow passage cross-sectional area in the conventional technology shown in Fig. 2 ■
is given by the following equation.

l-7 (P-C2) However; C-Outer diameter of frame 23 - Inner diameter of cooling jacket 24 In this case, if C, =C, D, =C, then the relationship I>11 is established.

Therefore, the circulation speed of the cooling water in the submersible rotating electrical machine according to this actual case is very high, which improves the cooling effect.

At the same time, I,>J (where J is the drain pipe 33a).

33b), the flow rate of the cooling water descending through the drain pipes 33a and 33b becomes even faster, thereby improving the cooling effect.

As explained above in detail with the embodiments, in the present invention, the drainage pipe is formed integrally with the frame, so compared to the conventional technology shown in Fig. 1, the bulk of the aircraft body can be reduced and costs can be reduced. It is possible.

At the same time, since spiral cooling fins can be provided on the outer periphery of the frame, the heat dissipation area becomes larger compared to the conventional technology shown in Figure 2, and the circulation speed of cooling water can also be increased. This greatly improves the cooling effect.

As a result, substantial cost reduction can be achieved.

[Brief explanation of the drawing]

Figures 1 and 2 are longitudinal cross-sectional views showing the prior art; Figure 3;
1. Figure 3 is a diagram showing an actual case of the present invention, and Figure 3 a is a diagram showing an actual case of the present invention.
FIG. 3 is a cross-sectional view taken along the line B-0-B in FIG. 3, and FIG. 3 is a cross-sectional view taken along the line A-A in FIG. 3a. In the drawing, 2 is a stator core, 5 is a pump casing, 31
33 is a rotating electric machine part, 33 is a frame, and 33a. 33b is a drainage pipe, 33c and 33d are thick walled parts, 37
A is a water supply hole, 37b and 37c are drain holes, and 38 is a cooling fin.

Claims (1)

[Scope of utility model registration request] By filling and circulating cooling water pumped up from inside the pump casing through the water supply hole into the space formed between the inner circumferential surface of a cooling jacket surrounding the frame of the rotating electric machine section and the outer circumferential surface of the frame. In the submersible rotating electrical machine that cools the frame, the frame is formed so that its outer shape in a cross section is elliptical, and its inner shape in contact with the stator core is circular; A drainage pipe, which is an arc-shaped long slit extending in the axial direction of the frame, is provided in the thick part of the ellipse formed between the outer circumferential surface and the inner circumferential surface of the frame in the long axis direction. The upper end is opened to the space formed by the cooling jacket and the frame, and the lower end thereof is opened to the outside through a drainage hole, and spiral cooling fins are provided on the outer peripheral surface of the frame. Cooling structure for submersible rotating electric machines.