Thrust bearing cooling device

The purpose of the present disclosure is to provide a thrust bearing cooling device which can improve the cooling efficiency of a thrust bearing. A thrust bearing cooling device comprising: a fluid storage tank in which a thrust bearing is installed and a fluid is stored, an outer surface of the fluid storage tank being exposed to external air; and at least one heat exchange fin provided in the fluid storage tank.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a 35 U.S.C. § 371 U.S. national entry of International Application PCT/KR2018/006992, having an International filing date of Jun. 21, 2018, which claims priority under 35 U.S.C. § 119 the benefit of Korean Application 10-2017-0078688 filed on Jun. 21, 2017. The entire contents of these applications are incorporated herein by reference in their entirety.

TECHNICAL FIELD

The present disclosure relates to a thrust bearing cooling device, and more particularly, to a thrust bearing cooling device in which a thrust bearing is primarily cooled by circulating a lubricating and cooling fluid, and secondarily cooled by exchanging heat between the fluid and air.

BACKGROUND ART

Vertical electric motors that provide rotational force to load devices such as pumps should support relatively high thrust loads occurring in the load devices.

A thrust bearing may be applied to a rotary shaft of the electric motor, to reduce friction of the rotary shaft of the electric motor, as well as to support the thrust loads therefrom.

Since such a thrust bearing receives relatively high thrust loads, friction loss may occur, and energy lost in the friction loss may be converted into heat energy, and the heat energy may act as a heat source for raising a temperature of the thrust bearing.

In addition, if the temperature of the thrust bearing is increased, components may be deteriorated and damaged. Therefore, a problem in which the maximum allowable support load of the bearing itself is reduced may occur.

Therefore, as a technique for lubricating and cooling the thrust bearing, there is a cooling device configured to immerse the thrust bearing in oil stored in an oil tank.

A thrust bearing cooling device equipped with an oil tank is disclosed in Korean Patent Publication No. 10-2012-0003205.

The thrust bearing cooling device including such an oil tank circulates a lubricating oil performing lubrication and cooling functions, in the oil tank, by using suction force generated in rotating the thrust bearing, to cool the thrust bearing, and heat exchange the oil tank with external air to cool the lubricating oil.

However, the thrust bearing cooling device according to the prior art has a disadvantage in that the heat exchange ratio between the lubricating oil and the oil tank is relatively low, and the heat exchange ratio between the oil tank and the external air is relatively low, because the oil tank is formed in a simple box shape.

DISCLOSURE

Technical Problem

The present disclosure has been made to solve at least some of the problems of the prior art as described above, and, an aspect of the present disclosure is to provide a thrust bearing cooling device in which cooling efficiency of a thrust bearing is improved.

Technical Solution

According to an aspect of the present disclosure, a thrust bearing cooling device includes: a fluid storage tank in which a thrust bearing is installed and a fluid is stored, an outer surface of the fluid storage tank being exposed to external air; and at least one heat exchange fin provided in the fluid storage tank.

According to another aspect of the present disclosure, a thrust bearing cooling device includes: a fluid storage tank in which a thrust bearing is installed and a fluid is stored, an outer surface of the fluid storage tank being exposed to external air; and at least one lower heat dissipating fin provided on a lower surface of a bottom portion of the fluid storage tank.

According to another aspect of the present disclosure, a thrust bearing cooling device includes: a fluid storage tank in which a thrust bearing is installed and a fluid is stored, an outer surface of the fluid storage tank being exposed to external air; at least one heat exchange fin provided on an inner side surface of a bottom portion of the fluid storage tank; and at least one lower heat dissipating fin provided on a lower surface of the bottom portion of the fluid storage tank.

Advantageous Effects

According to an aspect of the present disclosure having such a configuration, the cooling efficiency of the thrust bearing may be improved, and the life span of the thrust bearing and the maximum allowable supporting load may increase.

BEST MODE FOR INVENTION

The terminology used herein is for describing particular embodiments only, and is not to be used to limit the present disclosure. Further, the singular forms, such as the forms starting with the articles “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Various embodiments of the present disclosure will now be described with reference to the accompanying drawings.

First, with reference toFIGS. 1 and 2, a specific configuration of a thrust bearing cooling device100according to an embodiment of the present disclosure will be described.

As illustrated inFIGS. 1 and 2, a thrust bearing cooling device100according to an embodiment of the present disclosure may include a fluid storage tank110, a bearing seat120, a bearing runner130, a cooling fan140, a fan guide142, a side heat dissipating fin150, a heat exchange fin160, a fluid guide170, and a lower heat dissipating fin180.

For reference,FIGS. 1 and 2illustrate a structure in which a thrust bearing20is installed on an upper portion of a rotary shaft10of a vertical electric motor, but are not limited thereto. The thrust bearing20may be also installed on a lower portion of the rotary shaft10of the vertical electric motor.

The fluid storage tank110may be a box-shaped member in which a fluid may be stored, and an outer surface of the fluid storage tank may be exposed to external air.

The thrust bearing20may be installed in a central portion of the fluid storage tank110, to be immersed in the fluid stored in the fluid storage tank110. The rotary shaft10of the vertical electric motor coupled to the thrust bearing20may be disposed to pass through the central portion of the fluid storage tank110.

In this case, the fluid may be lubricating oil in the thrust bearing20. This fluid may flow into an inner wheel of the thrust bearing20by suction force of a bearing roller22generated in rotating the bearing roller22of the thrust bearing20due to rotation of the rotary shaft10, and may then flow out of an outer wheel of the thrust bearing20, such that the fluid may be circulated via the thrust bearing20in the fluid storage tank110.

In an embodiment, the fluid storage tank110may include a side wall112having a cylindrical shape, a ceiling portion114for sealing an upper end of side wall112, a bottom portion116for sealing a lower portion of the side wall112, and a sleeve118extending in an upward direction to surround the rotary shaft10in the bottom portion116.

The bearing seat120may be provided in the fluid storage tank110, and may fix the thrust bearing20to the bottom portion116of the fluid storage tank110.

In an embodiment, the bearing seat120may be configured in a cylindrical shape in which the thrust bearing20is coupled to an upper portion of the bearing seat. In this case, a space may be formed between an inner side surface of the bearing seat120and the sleeve118of the fluid storage tank110.

In addition, the bearing seat120may have a fluid flow hole122formed to pass through from an outer side surface of the bearing seat to an inner side surface of the bearing seat in a radial direction of the bearing seat120. In this case, the fluid flow hole122may be formed, in plural, at intervals in a circumferential direction of the bearing sheet120.

In an embodiment, the fluid flow hole122may be formed to be horizontal to the ground, such that the fluid flows smoothly, but is limited thereto.

The bearing runner130may be provided inside the fluid storage tank110, and may rotatably support a rotary wheel of the thrust bearing20with respect to the ceiling portion114of the fluid storage tank110. The bearing runner130may mediate coupling between the rotary wheel of the thrust bearing20and the rotary shaft10of the vertical electric motor.

The cooling fan140may be disposed above the fluid storage tank110, and may be fastened to the rotary shaft10of the vertical motor. The cooling fan140may be rotated by rotation of the rotary shaft10, to generate an air flow rubbing against the outer surface of the fluid storage tank110.

The fan guide142may surround the fluid storage tank110and the side heat dissipating fin150to be described later, and may guide an air flowing by suction force of the cooling fan140to the cooling fan140. In an embodiment, the fan guide142may be configured in a cover shape covering the fluid storage tank110, and a lower end of the fan guide may extend in a downward direction, to concentrate the air on the outer surface of the fluid storage tank110and the side heat dissipating fin150.

The side heat dissipating fin150may be provided on an outer surface of the side wall112of the fluid storage tank110, and may exchange heat with the external air.

In an embodiment, the side heat dissipating fin150may be formed in a vertical direction, depending on a flow direction of the air flowing by the cooling fan140. In addition, the side heat dissipating fins150may be provided, in plural, at intervals along a circumference of the fluid storage tank110.

The heat exchange fin160may be provided in the fluid storage tank110, may exchange heat with a fluid stored in the fluid storage tank110, and may transfer heat to the fluid storage tank110. This heat exchange fin160may increase a heat exchange area between the fluid and the fluid storage tank110.

In an embodiment, the heat exchange fin160may be coupled to the bottom portion116of the fluid storage tank110, and may be disposed, in plural, at intervals in the circumferential direction of the thrust bearing20.

The plurality of heat exchange fins160may be provided in a radial direction with respect to the thrust bearing20, depending on a flow direction of a fluid circulating in the fluid storage tank110.

In addition, in an embodiment, the plurality of heat exchange fins160may be disposed such that an inner end thereof faces the fluid flow hole122formed in the bearing seat120. Through this configuration, the fluid may exchange heat with the heat exchange fin160, and may be guided to the fluid flow hole122by the heat exchange fin160, such that the circulation flow of the fluid may be smoother.

In this configuration, when the inner end of the heat exchange fin160extends to a position near the bearing seat120, a flow path through which the fluid flows into the fluid flow hole122of the bearing seat120may be divided into a plurality of sections. Therefore, flow of the fluid flowing into the fluid flow hole122may not be smooth.

Therefore, the inner end of the heat exchange fin160may be spaced apart from the bearing sheet120, to smoothly flow the fluid around the outer side surface of the bearing sheet120.

Also, in an embodiment, the heat exchange fin160may extend to a position in which the outer end is adjacent to the side wall112of the fluid storage tank110, to increase the heat exchange area. The outer end of the heat exchange fin160may be spaced from the side walls112of the fluid storage tank110, not to divide the flow path of the fluid into a plurality of sections.

The fluid guide170may be a plate-like member covering the upper portions of the plurality of heat exchange fins160. The fluid guide170may guide a fluid discharged from the thrust bearing20to the outer end of the heat exchange fin160, to maximize a heat exchanging time and a heat exchanging area. Therefore, the efficiency of heat exchange between the heat exchange fin160and the fluid may increase.

The fluid guide170may extend toward an outer end of the heat exchange fin160, to flow a fluid discharged from the thrust bearing20to the outer end of the heat exchange fin160.

In an embodiment, the fluid guide170may be configured in a donut shape extending from the outer side surface of the bearing seat120in a radial direction, but is not limited thereto.

The fluid guide170may be coupled to an upper end of a portion of the heat exchange fins160, among the plurality of heat exchange fins160, to prevent sagging of the fluid guide, but is not limited thereto, and may be coupled to the outer side surface of the bearing seat120.

Also, in an embodiment, the fluid guide170may flow a fluid discharged from the thrust bearing20to the inner wall of the fluid storage tank110, to increase the efficiency of heat exchange between the inner wall of the fluid storage tank110and the fluid. In this case, the inner wall of the fluid storage tank110may be cooled by transferring heat to the side heat dissipating fin150.

To this end, the fluid guide170may extend, for example, an outer diameter of the fluid guide to 50% to 95% of an inner diameter of the fluid storage tank110, but is not limited thereto.

In addition, in an embodiment, the fluid guide170may be configured to be horizontal to the ground, to facilitate fluidity of a fluid flowing in the radial direction and at the same time to increase a flow rate of a fluid flowing the outer ends of the heat exchange fins160.

Alternatively, when the fluid guide170is sloped in an upward direction as it moves in an outward direction, the fluid may not pass over the fluid guide170, and may stay in the fluid guide170. Therefore, circulation of the fluid may not be smooth.

In addition, when the fluid guide170is sloped in a downward direction as it moves in an outward direction, a flow rate flowing into a space between the inner upper end of the heat exchange fin160and the fluid guide170may increase. Therefore, the efficiency of heat exchange between the fluid and the heat exchange fin160may be rather reduced.

Also, in an embodiment, the fluid guide170may be not excessively spaced apart from the heat exchange fin160, to maximize the efficiency of heat exchange between the fluid and the heat exchange fin160.

To this end, the fluid guide170may be disposed between an upper end of the fluid flow hole122and a 50% position in height of the bearing seat120, but is not limited thereto, and may be configured to have different sizes depending on height.

The lower heat dissipating fin180may be provided on the lower surface of the bottom portion116of the fluid storage tank110, and may exchange heat with the external air. The lower heat dissipating fin180may receive heat from the bottom portion116of the fluid storage tank110, and may discharge the heat externally.

In this configuration, the heat of the fluid transferred to the heat exchange fin160may be transferred to the lower heat dissipating fin180through the bottom portion116of the fluid storage tank110, and the lower heat dissipating fin180may exchange the heat with the external air to discharge the transferred heat externally.

In an embodiment, the lower heat dissipating fin180may be provided, in plural, at intervals in a radial direction with respect to a center of the fluid storage tank110.

For example, the lower heat dissipating fin180may be configured to correspond to the heat exchange fin160in a one-to-one correspondence manner in terms of the number and position, but is not limited thereto.

In an embodiment, the lower heat dissipating fin180may have a protruded portion182protruding in a radial direction on the bottom portion116of the fluid storage tank110and disposed below the side heat dissipating fin150.

In this case, the lower end of the fan guide142may be disposed at the upper end of the lower heat dissipating fin180. The fan guide142having such a structure may guide the air flowing by the cooling fan140and heat exchanged with the lower heat dissipating fin180to the side heat dissipating fins150. When the lower end of the fan guide142is excessively spaced apart from the upper end of the lower heat dissipating fin180, a flow rate of the air flowing directly to the side heat dissipating fin150without passing through the lower heat dissipating fin180may increase to deteriorate the efficiency of heat exchange of the lower heat dissipating fin180.

When the lower heat dissipating fin180is excessively high, it may be not easy to introduce the working tool at a distance between the plurality of lower heat dissipating fin180. Therefore, workability of joining to the lower surface of the bottom portion116of the lower heat dissipating fin180may be deteriorated.

Therefore, the lower heat dissipating fin180may be formed at a relatively low height for assembly workability. When the lower heat dissipating fin180is relatively low, there may be a disadvantage that the heat exchange area becomes narrow.

Therefore, in an embodiment, the lower heat dissipating fin180may be configured to have larger area toward the protruded portion182, in a portion coupled to the bottom portion116of the fluid storage tank110, as illustrated inFIGS. 1 and 2. In this case, an air flowing into the side heat dissipating fin150may most actively exchange heat in the protruded portion182of the lower heat dissipating fin180.

FIG. 3illustrates a state in which cooling function of the thrust bearing cooling device100according to an embodiment of the present disclosure is inactivated.FIG. 4illustrates a state in which cooling function of the thrust bearing cooling device100according to an embodiment of the present disclosure is activated.

In this case, the cooling function of the thrust bearing20may be activated, in conjunction with the rotation of the rotary shaft10of the vertical electric motor.

As illustrated inFIG. 3, the fluid may be stored in the fluid storage tank110at a level approximating a height of a portion from which the fluid of the thrust bearing20is discharged.

When the rotary shaft10coupled to the thrust bearing20rotates, the fluid stored in the fluid storage tank110may be circulated via the thrust bearing20, as illustrated inFIG. 4, and the external air may flow along the side surface at the lower end of the fluid storage tank110by the cooling fan140.

In this case, the fluid circulating in the fluid storage tank110may cool the thrust bearing20, and transfer heat to the fluid storage tank110and the heat exchange fin160.

The heat transferred to the heat exchange fin160may be transferred to the lower heat dissipation fin180through the bottom portion116of the fluid storage tank110, and the lower heat dissipation fin180may exchange the heat with the air, to release the heat externally.

In this case, since the lower heat dissipating fin180may be initially a component in which heat is not exchanged with other components, the heat may be relatively exchanged with the ambient air having the lowest temperature. Therefore, the present disclosure may have an advantage that the cooling performance of the fluid is remarkably improved by the heat dissipating fin180and the heat exchange fin160transmitting heat to the lower heat dissipating fin180.