JPH0450512A - Heat pipe device - Google Patents

Abstract

PURPOSE:To provide a bottom heat-top cool heat pipe device capable of cooling a heating body by defining an axial gap of a spiral flexible part and average radius with predetermined dimensions to reduce fluid resistance and ensure flexibility. CONSTITUTION:A heat absorbing section at the lower side of a heat pipe 4 is embedded directly in a bearing segment 1, and a vertical spiral flexible part 4c capable of relative movement of fixed parts in all directions is provided vertically between the fixed parts of the lower side heat absorbing and the upper side radiating part. The axial gap P is set to at least 1.5 times heat pipe diameter d to reduce the fluid resistance of oil flow in an oil tank 2 and the average radius R is set to at least 4 times heat pipe diameter d to ensure the flexibility. Thus, the relative repetitive displacement between the fixed parts of the lower side heat absorbing part and the upper side radiating part is absorbed by the spiral flexible part 4c, and the lower side heat absorbing part can be embedded directly in the bearing segment 1 to provide a bottom heat-top cool heat pipe device capable of cooling a heating body.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a heat pipe device.

[Conventional technology]

Heat pipes were originally used in the so-called Bottom heat-Topcool method, with the heat absorption part on the bottom and the heat radiation part on the top. This is a cooling device that quickly returns the liquid to the endothermic part by the action of gravity or the synergistic action of the capillary action of the core material and gravity, and then evaporates it again to efficiently transport heat from the endothermic part to the heat radiating part.

Therefore, on the contrary, a usage method in which the heat absorbing part is placed on the upper side and the heat radiating part is attached on the lower side goes against the circulation of the steam flow and condensation liquid by gravity, and may not be possible, or may not be possible due to the core material. Therefore, the performance of the heat pipe under the optimum usage conditions cannot be utilized.

In the device described in Japanese Unexamined Patent Publication No. 55-129621, a heat pipe is directly embedded in a movable heating section, so that the weight of the entire heat pipe device is supported by the heating object. In this point, since the length of the heat pipe is limited, a flexible part is not provided in the middle of the heat pipe, but in the usage method, Bottom cool-Top heat
Although it uses cooling water at a lower temperature than cold air as the cooling material for the heat dissipation part, the positional relationship in use is fundamentally contrary to the method of using heat pipes. Therefore, the capabilities of heat pipes are not fully utilized.

A practical example of a heat pipe for a general conventional thrust bearing device other than this example is shown in FIG. This is an indirect heat pipe cooling in which the heat absorbing part of the heat pipe 4 is thrown into the lubricating oil 3, and the heat dissipating part is Installed in the refrigerant outside the oil tank. In the figure, 4a and 4b are radiation fins of the heat pipe 4, 5 is a rotating shaft, and 6 is a rotating disk.

[Problem to be solved by the invention]

When a heat pipe is mounted directly on a thrust bearing, there is a relative vertical repetitive displacement between the heat absorbing and heat dissipating parts, which is why traditional integral heat pipes are not made of the material (generally copper tube with good thermal conductivity). ) could not be applied to the cooling of the heating element due to the limitation of fatigue strength of
The purpose is to provide a cool heat pipe device.

[Means to solve the problem]

The above purpose is to embed the lower heat absorbing part of the heat pipe directly into the bearing segment, and to allow relative movement of the fixed part in all directions between the lower heat absorbing part and the upper heat dissipating part. A spiral-shaped flexible part is provided perpendicular to the vertical direction, and the axial gap P of this spiral-shaped flexible part is set to 1.5 times or more the heat pipe diameter d to reduce the fluid resistance of the oil flow in the oil tank. However, this is achieved by ensuring flexibility by setting the average radius R of the spiral flexible portion to at least four times the heat pipe diameter d.

In other words, the heat pipe is designed so that the operating temperature at which the heat pipe exhibits its best performance (the average of the temperature of the heat absorption part and the temperature of the heat radiation part) approaches the maximum value of the heat pipe's heat transport efficiency curve. The heat absorbing part is inserted directly into the heated object (bearing segment) with the highest temperature, while the heat dissipating part is installed so that it is located in the coolant medium with the lowest temperature. The vertical relative repetitive displacement between both ends of the heat pipe is absorbed by a spiral-shaped flexible section provided between both ends of the heat pipe, so that fatigue stress is not applied to the attachment parts of the metal heat pipes on both sides. did.

[Effect]

Since the above means is provided, the relative repetitive displacement between the lower heat absorption part and the fixed part of the upper heat dissipation part is scaled by the spiral flexible part, and the lower part of the heat pipe is Direct embedding of the heat absorbing part into the bearing segment (heating body) becomes possible.

In other words, with a heat pipe that can scale the relative displacement difference in the vertical direction, the heat absorption part and the heat radiation part can be maintained in a vertical positional relationship without applying force to either end of the heat pipe, that is, by applying stress due to displacement to the mounting parts on both sides. It is possible to cool the bearing segment at the optimum position of use of the heat pipe without causing heat generation.

For this reason, it is basically no longer necessary to attach a core material inside the heat pipe to generate capillary action at both ends and the flexible part of the heat pipe, and the heat absorbing part upwards due to the action of gravity. The liquid that evaporates and reaches the heat sink, is cooled and condenses, and returns to the heat sink due to the action of gravity.

The spiral-shaped flexible part has the heat pipe itself in a spiral shape, and by making the axial direction of this spiral-shaped flexible part vertical, the condensed liquid after heat radiation flows down along the slope of the spiral part, There is also no rise of steam from the heat absorption part of the heat pipe.

〔Example〕

The present invention will be explained below based on the illustrated embodiments. An embodiment of the invention is shown in FIGS. 1 and 2. FIG. Note that parts that are the same as those in the prior art are given the same reference numerals, and therefore their explanations will be omitted. In this embodiment, the lower heat absorbing part of the heat pipe 4 is directly embedded in the bearing segment 1, and the relative movement of the fixed part in all directions is controlled between the fixed part of the lower heat absorbing part and the upper heat dissipating part. A spiral flexible portion 4c vertical to the vertical direction is provided, and the IP between the spiral flexible portions 4C in the axial direction is set to be at least 1.5 times the heat pipe diameter d to control the oil flow in the oil tank 2. The average radius R of the spiral flexible portion 4c is set to four times or more the diameter d of the heat pipe to ensure flexibility. By doing this, the relative repetitive displacement between the fixed parts of the lower heat absorbing part and the upper heat radiating part is scaled by the spiral flexible part 4c, and the bearing of the lower heat absorbing part Bot that can be directly embedded in segment 1 and allows cooling of the heating element
A tom heat-Top cool heat pipe device can be obtained.

That is, in a thrust bearing, a wedge-shaped oil film is formed on the edge surface between the rotating disk 6 and the bearing segment 1 by the relative sliding of the lubricating oil 3 between the rotating disk 6 and the bearing segment 1. As a result, as shown in FIGS. 3 and 4, the bearing segment 1 moves by h on the inlet side in the sliding direction and by h2 on the 8th port side each time it starts and stops. Due to this oil film formation effect, the bearing segment 1 is vertically displaced relative to the fixed portion by the vertical displacement difference due to the inclination of the bearing segment 1 during rotation from the stationary state indicated by the dotted line in the figure. On the other hand, loss occurs on the sliding surface due to viscous shear stress acting on the oil film, which increases the temperature of the oil film, resulting in heat transfer from the oil film to the bearing segment 1.
is higher than the surrounding lubricating oil temperature, especially on sliding surfaces, where the oil film thickness is thinner and the sliding speed is higher.
resulting in higher temperature rise.

The cross-section where this temperature distribution reaches its maximum in the radial direction is shown by a-b-c-d in FIG. 3, and the cross-section where the temperature distribution reaches its maximum in the circumferential direction is shown by a-b-c-d in the figure. Figure 5 shows the magnitude of the temperature distribution values for the a-b-c-d cross section using arrow-like lengths, and Figure 6 shows the same for the A-B-C-D cross section. It is a diagram. From these two figures, the temperature of the bearing segment 1 is highest at the intersection of the a-b-c-d cross section and the A-B-C-D cross section in Fig. 3, and the closer it is to the edge surface, the higher the temperature is. The temperature is high.

Further, FIG. 7 shows the efficiency curve of the amount of heat transported against the operating temperature of the heat pipe (the average value of the temperature of the heat absorption part and the temperature of the heat radiation part) for a typical example. Since the heat pipe has a certain diameter, in order to insert it into the bearing segment, it is necessary to insert it so that the heat pipe is not exposed to the sliding surface, and the highest temperature point a-b- found from Fig. 3 is reached. It is necessary to insert the heat pipe slightly below the sliding surface of the intersection cross section of c-d and A-B-C-D.In practice, it is necessary to insert the heat pipe slightly below the sliding surface of the intersection cross section of bearing segment 1 as shown in Fig. 8. Bearing segment 1 that intersects with the radial cross section and is the position where the heat pipe 4 can be inserted and where the temperature is the highest
Insert it into the specified position on the sliding direction side. If the rotating machine is reversible, insert the heat pipe 4 in the position (a) in the figure and also in the circumferential center-symmetrical position (b) to achieve the same cooling effect in either reversible rotation direction. I decide to have it.

As shown in FIG. As shown in the diagram, the heat dissipation part of the heat pipe 4 is connected to the outside of the oil tank 2 where the refrigerant is flowing, and the heat pipe 4 is attached with heat dissipation fins 4a to increase the cooling capacity and is firmly fixed to the upper part of the oil tank 2. , a heat pipe circuit in which a spiral flexible portion 4c is provided in the middle portion of the heat pipe 4. The relative displacement due to the vertical displacement difference h (see FIG. 4) of the bearing segment 1 with respect to the oil tank 2 is determined by the spiral-shaped flexible part of the heat pipe 4 that is provided in the middle of the heat pipe 4 and is flexible in all directions. Since the series is carried out at part 4C, repeated tensile stress and repeated bending stress are not applied to either the mounting part on the bearing segment 1 side or the mounting part on the oil tank 2 side of the heat pipe 4, and therefore metal fatigue rupture of the heat pipe mounting part is prevented. can be prevented.

In this way, the heat absorbing part of the heat pipe is inserted directly into the high temperature part of the bearing segment 1, and is located in the low temperature refrigerant passage, although it is away from the heat dissipating part, and both are placed in the Bottomheat- Top cool
Make it available for use. Incidentally, if the thrust bearing segment of a rotating electrical machine is cooled in this way, the operating temperature will be (heat absorption part temperature approximately 0°C + heat radiation part temperature approximately 30'C)/2 = 600
C, which is close to the maximum position of 85°C in the case of vertical bottom heating shown in Fig. 7 (a), and it becomes possible to transport a large amount of heat with a heat pipe of a constant capacity, and as a result,
Economic benefits can be obtained by improving the performance of heat pipe devices and reducing their size.

For example, instead of the vertical bottom heat as in this embodiment,
When used horizontally as shown in Figure (b), the operating temperature is 60'C as above.
Comparing the heat transport amount in the case of , the heat transport amount in the case of vertical bottom heat with an operating temperature of 60 °C is approximately 2800 (, W) (
(see Figure 7(a)), the amount of heat transport when used horizontally is approximately 4
Since it is 00 (W), it becomes 2800/400~7. In this way, in the case of vertical bottom heat, the heat transport amount is seven times greater than in the case of horizontal use, which shows how the use of vertical bottom heat can effectively utilize the performance of the same heat pipe.

FIG. 2 shows how the spirally shaped flexible portion of this heat pipe is formed. A stirring oil flow in the circumferential direction is generated in the oil tank by the rotation of a rotating disk.

In order to reduce the fluid resistance force that the heat pipe 4 receives due to this oil flow, a gap P is provided in the direction of the spiral axis so as not to impede the oil flow. The figure also shows the manufacturing limit bending radius of the heat pipe 4, which is mainly made of copper, and the conditions for appropriately determining the average radius R in order to obtain the necessary flexibility. That is, R≧4d, P≧1.5d
This provides the necessary flexibility. Also, P≧
By setting it to 1°5d, the oil flow resistance is reduced and the lubricating oil flows smoothly, and by increasing P, not only does the lubricating oil flow smoothly, but also the condensed liquid easily returns to the heat absorption part. . Further, by setting R≧4d, not only flexibility can be obtained but also manufacturing is easy.

In this way, according to this embodiment, by providing the vertical spiral flexible part in the middle part of the heat pipe, even when there is a relative repetitive displacement difference between the heat absorption part side and the heat radiation part side of the heat pipe. , by separately fixing both sides of the heat pipe to the object to be cooled (heating object) and the cooling medium passage,
It can be used in the best condition as a heat pipe for heat-top cool. Also, Bottom
Since heat=Top cool, the operating temperature can be brought close to the maximum point on the heat pipe operating temperature-heat transport efficiency curve. Furthermore, since the temperature difference between the heat absorption part and the heat radiation part can be increased, the total amount of heat transfer, which is the product of this temperature difference and the efficiency related to the operating temperature, can be increased, and a higher cooling capacity than the conventional example can be obtained. I can do it.

〔Effect of the invention〕

As mentioned above, the present invention provides a Bot that enables cooling of a heating element.
Now that a bottom heat-top cool heat pipe device can be obtained, a bottom heat-top cool heat pipe device that can cool a heating element can be obtained.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional side view of a thrust bearing device according to an embodiment of the heat pipe device of the present invention, FIG. 2 is an explanatory diagram showing a spiral-shaped flexible portion of the same embodiment, and FIG. 3 is a bearing of the bearing device. FIG. 4 is a perspective view of the segment; FIG. 4 is a view from the Q arrow in FIG. 3; FIG. 5 is a front view showing the radial temperature distribution during operation of the bearing segment of the bearing device; FIG. 6 is the bearing segment of the bearing device as well. Figure 7 (a) and (b) are front views showing the circumferential temperature distribution during operation of the heat pipe.
) is for vertical bottom heat, and (b) is a characteristic diagram showing the relationship between operating temperature and maximum heat transport amount when using water.
FIG. 9 is a perspective view showing a state in which a peel L-pipe of an embodiment of the heat pipe device of the present invention is inserted into a bearing segment;
The figure is a vertical side view of a thrust bearing device using a conventional heat pipe device. 1...Bearing segment, 2...Oil tank, 4...Heat pipe, 4C...Spiral-shaped flexible part

Claims (1)

[Claims] 1. A heat pipe is provided for cooling a bearing segment of a bearing device installed in an oil tank of a rotating machine, and the heat pipe is installed in a lower heat absorption part and a refrigerant passage outside the oil tank. In a heat pipe device having an upper heat dissipation part,
The lower heat absorbing part of the heat pipe is directly embedded in the bearing segment, allowing relative movement of the fixed part in all directions between the lower heat absorbing part and the upper heat dissipating part. A spiral-shaped flexible part is provided vertically in the vertical direction, and the axial gap P of this spiral-shaped flexible part is set to be 1.5 times or more the heat pipe diameter d to reduce the fluid resistance of the oil flow in the oil tank. The heat pipe device 2 is characterized in that the average radius R of the spiral flexible portion is set to four times or more the diameter d of the heat pipe to ensure flexibility; 2. The heat pipe according to claim 1, wherein the heat pipe is inserted at a position where the circumferential cross section and the radial cross section of the bearing segment intersect, and at a predetermined position on the sliding direction side of the bearing segment where the temperature is highest. 2. The heat pipe device 4 according to claim 1, wherein the heat pipe has a core member inserted therein that extends in the longitudinal direction over the entire inner circumference of the heat pipe, and the spiral flexible portion The heat pipe device 5 according to claim 1, wherein the lower heat absorbing part and the upper heat radiating part are formed to have flexibility in a direction perpendicular to each other. 2. The heat pipe device 6 according to claim 1, wherein the heat absorbing part is at the bottom and the heat dissipating part is at the top with respect to gravity. 2. The heat pipe device 7 according to claim 1, wherein the heat pipe device 7 is made of the same material as the material and formed into a spiral spring, and the spiral flexible portion is formed of a plastic or rubber tube reinforced with steel wire. The heat pipe device according to claim 1, which is