KR102417243B1 - LNG pump with improved bearing lubrication and cooling performance - Google Patents

Abstract

The present invention relates to a liquefied natural gas (LNG) pump capable of lubricating and cooling a bearing installed inside the LNG pump using LNG transported by the LNG pump. The LNG pump with improved bearing lubrication and cooling performance comprises: a casing including an upper receiving portion formed on an inner upper portion, a lower receiving portion formed in an inner lower portion, an inlet formed on the lower side of a lower receiving portion to be connected to the lower receiving portion, an outlet formed on the upper side of the upper receiving portion, and a passage formed to connect the lower receiving portion and the outlet; shafts installed to extend vertically in the center of the upper and lower receiving portions of the casing; a rotor coupled to the shaft to be disposed in the upper receiving portion of the casing; a stator installed on an inner wall of the upper receiving portion of the casing to surround the rotor; and an impeller coupled to the shaft to be disposed in the lower receiving portion of the casing. A through hole connecting the upper receiving portion and the outlet is formed between the upper receiving portion and the outlet. A nozzle is installed in the through hole to spray a portion of the LNG which has passed through the passage toward a bearing mounted on an upper end of the shaft.

Description

LNG pump with improved bearing lubrication and cooling performance

The present invention relates to an LNG pump with improved bearing lubrication and cooling performance, and more particularly, lubricating and cooling the bearing installed inside the LNG pump using LNG (Liquefied Natural Gas) transported by the LNG pump. It is related to the LNG pump that made it possible.

'Cryogenic low pressure pump for LNG transport' (hereinafter referred to as 'prior art') of Republic of Korea Patent Publication No. 10-2016-0005463 (published on Jan. 15, 2016) is proposed as a technology related to an LNG pump.

The prior art is "as a cryogenic low pressure pump capable of applying a predetermined pressure to the fluid in a state immersed in a cryogenic fluid; it has an inlet (IN) through which the fluid flows, and a plurality of compression spaces with a larger diameter than the inlet. an inducer installed in the inlet of the casing to suck the fluid by rotation; a plurality of impellers rotatably supported in each compression space and applying pressure to the fluid by rotation; A plurality of diffusers fixed to the casing from the inside and diffusing the fluid applied by the impeller while maintaining the same pressure; A shaft installed to connect the center of the inducer and the impeller and interlocking; A motor mechanism for rotating the inner manifold installed at the outlet end of the casing and guiding the fluid passing through the diffuser to a plurality of outlets formed on the outlet side, connected to the outlet of the inner manifold, and the outlet of the inner manifold A cryogenic low pressure pump consisting of a plurality of discharge pipes supported on the side; it is technology

[Document 1] Republic of Korea Patent Publication No. 10-2016-0005463 (published on January 15, 2016)

An object of the present invention is to provide an LNG pump in which the lubrication and cooling performance of the bearing can be improved by using LNG transferred by the LNG pump to lubricate and cool the bearing installed inside the LNG pump.

The problems to be solved by the present invention are not limited to the aforementioned problems. Other technical problems not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention belongs from the following description.

In order to solve the above problems, the LNG pump with improved bearing lubrication and cooling performance according to an embodiment of the present invention is configured to be connected to the upper accommodating part formed on the inner upper part, the lower accommodating part formed on the inner lower part, and the lower accommodating part. a casing including an inlet formed at a lower side of the lower receiving unit, an outlet formed at an upper side of the upper receiving unit, and a flow path formed to connect the lower receiving unit and the outlet; a shaft installed to extend vertically in the center of the upper and lower receiving portions of the casing; a rotor coupled to the shaft so as to be disposed in the upper receiving portion of the casing; a stator installed on the inner wall of the upper accommodating part of the casing to surround the rotor; and an impeller coupled to the shaft so as to be disposed in the lower accommodating part of the casing; a through hole connecting the upper accommodating part and the outlet is formed between the upper accommodating part and the outlet, and the through hole has the flow path A nozzle is installed so that a portion of the LNG that has passed through is injected toward the bearing mounted on the upper end of the shaft.

In an embodiment of the present invention, the nozzle has a head portion having a discharge port, a coupling portion formed on an upper side of the head portion and screwed to the through hole, and a female screw portion formed on an inner periphery of the coupling portion, the inside of which is upward a lower body formed to be open; and an upper body having a male screw portion coupled to the female screw portion of the lower body and an inlet formed to be laterally opened on an upper side of the male screw portion, and formed to open downward.

In an embodiment of the present invention, the nozzle is installed to surround the upper part of the upper body and further comprises a mesh for filtering foreign substances from the LNG flowing into the inlet, and the upper surface of the mesh is provided at the upper end of the upper body. A supporting step is formed.

In an embodiment of the present invention, the upper end of the through hole is formed to protrude higher than the inlet of the nozzle, and the inner periphery of the through hole is formed to be spaced apart from the outer periphery of the mesh body.

In an embodiment of the present invention, a plurality of discharge ports of the nozzle are arranged on a pitch circle centered on the center of the head part to respectively spray LNG toward the rolling elements of the bearing, and each discharge port is formed on a flat surface. It penetrates in a tangential direction of the head portion when viewed, and is formed to inject LNG in a direction opposite to a rotational direction when the nozzle is screwed into the through hole.

According to the LNG pump according to the embodiment of the present invention, there is an effect that the lubrication and cooling performance of the bearing can be improved by injecting a part of the LNG transferred by the LNG pump to the bearing mounted on the upper end of the shaft through the nozzle.

In addition, according to the LNG pump according to the embodiment of the present invention, foreign substances contained in the LNG flowing into the inlet of the nozzle are filtered by the mesh body, so that damage and damage to the bearing due to the foreign substances can be prevented.

1 is a cross-sectional view of an LNG pump according to an embodiment of the present invention.
Fig. 2 is an enlarged cross-sectional view of the nozzle portion in Fig. 1;
3 is a perspective view of a nozzle in an LNG pump according to an embodiment of the present invention;
4 is an exploded perspective view of a nozzle in an LNG pump according to an embodiment of the present invention;
5 is an exploded perspective view of the bottom of the nozzle in the LNG pump according to the embodiment of the present invention.
6 is a bottom perspective view showing another embodiment of the nozzle in the LNG pump of the present invention.
7 is a bottom view showing another embodiment of the nozzle in the LNG pump of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. For convenience of description, components shown in the drawings may be exaggerated, omitted, or schematically represented.

1 is a cross-sectional view of an LNG pump according to an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view taken from the nozzle portion in FIG. 1, and FIG. 3 is a perspective view of a nozzle in an LNG pump according to an embodiment of the present invention. , FIG. 4 is an exploded perspective view of the nozzle in the LNG pump according to the embodiment of the present invention, and FIG. 5 is an exploded perspective view of the bottom of the nozzle in the LNG pump according to the embodiment of the present invention.

1 to 5 , the LNG pump according to the embodiment of the present invention includes an upper accommodating part 110 formed on the inner upper part, a lower accommodating part 120 formed on the inner lower part, and the lower accommodating part 120 . The inlet 130 formed on the lower side of the lower accommodating part 120 to be connected to, the outlet 140 formed on the upper side of the upper accommodating part 110, and the lower accommodating part 120 and the outlet 140 are connected a casing 100 including a flow path 150 formed to do so; a shaft 200 installed to extend vertically in the center of the upper accommodating part 110 and the lower accommodating part 120 of the casing 100; a rotor 300 coupled to the shaft 200 so as to be disposed in the upper accommodating part 110 of the casing 100; a stator 400 installed on the inner wall of the upper accommodating part 110 of the casing 100 so as to surround the rotor 300; and an impeller 500 coupled to the shaft 200 to be disposed in the lower accommodating part 120 of the casing 100; but, between the upper accommodating part 110 and the outlet 140, the upper A through hole 160 connecting the receiving unit 110 and the outlet 140 is formed, and a portion of LNG (Liquefied Natural Gas) that has passed through the flow path 150 is stored in the through hole 160 . It is characterized in that a nozzle 700 to be sprayed toward the bearing 600 mounted on the upper end of the shaft 200 is installed.

The shaft 200 , the rotor 300 , and the stator 400 form one motor to rotate the impeller 500 .

As described above, the casing 100 , the shaft 200 , the rotor 300 , the stator 400 , and the impeller 500 constituting the LNG pump are already known configurations, so a detailed description thereof will be omitted.

The greatest feature of the present invention lies in the structure of the through hole 160 and the nozzle 700 .

The through hole 160 is formed through the upper center of the upper accommodating part 110 to connect the outlet 140 and the upper accommodating part 110 , so that the lower accommodating part 120 is passed through the inlet 130 . ) and a portion of the LNG that has passed through the flow path 150 may be introduced into the upper receiving unit 110 .

The through hole 160 is formed of a female screw so that at least a lower portion thereof can be coupled to the nozzle 700 .

The nozzle 700 includes a head portion 712 having a discharge port 711 formed thereon, a coupling portion 713 formed on an upper side of the head portion 712 and screwed to the through hole 160 , and the coupling a lower body 710 having a female threaded portion 714 formed on the inner periphery of the portion 713, the inner portion being opened upwardly; An upper body having a male screw portion 721 coupled to the female screw portion 714 of the lower body 710 and an inlet 722 formed to be open laterally on the upper side of the male screw portion 721, the inside of which is opened downward (720); and a mesh 730 that is installed to surround the upper portion of the upper body 720 and filters foreign substances from the LNG flowing into the inlet 722 .

According to the nozzle 700 configured as described above, a portion of the LNG that has passed through the flow path 150 passes through the mesh 730 , the inlet 722 , and the outlet 711 and is mounted on the upper end of the shaft 200 . The lubrication and cooling performance of the bearing 600 may be improved by being sprayed toward the bearing 600 .

The diameter of the discharge port 711 of the nozzle 700 is particularly preferably formed to be about 1.5 mm in consideration of the discharge pressure of the LNG, and is preferably formed within the range of approximately 1.3 mm to 1.7 mm. When the diameter of the discharge port 711 is less than 1.3 mm, the amount of LNG injected decreases the lubrication and cooling performance of the bearing 600, and when it exceeds 1.7 mm, the amount of LNG leaked for lubrication and cooling increases, so that the performance may decrease.

The inlet 722 of the nozzle 700 is formed to have a larger area than the outlet 711 so that LNG can easily flow into the inside of the nozzle 700 . According to the embodiment of the present invention, the inlet 722 is formed in the shape of a long hole extending along the outer periphery on the upper portion of the upper body 720, and two are provided so as to be vertically spaced apart.

The mesh body 730 has a cylindrical shape and is fitted so as to be in close contact with the upper portion of the outer periphery of the upper body 720 . At this time, a step 723 for supporting the upper surface of the mesh body 730 is formed at the upper end of the upper body 720 . Accordingly, the mesh body 730 is interposed between the step 723 and the upper surface of the lower body 710 and is fixed.

The mesh body 730 is formed to have a mesh size of about 80 μm to 100 μm, more preferably a mesh size of about 90 μm, so that the discharge port 711 is caused by foreign substances introduced into the nozzle 700 . is prevented from being clogged, and the bearing 600 is prevented from being damaged or damaged by the foreign substances being injected into the bearing 600 together with the LNG.

Meanwhile, as shown in FIG. 2 , in a state in which the nozzle 700 is fastened to the through hole 160 , the upper end of the through hole 160 protrudes higher than the inlet 722 of the nozzle 700 . and the inner periphery of the through hole 160 may be formed to be spaced apart from the outer periphery of the mesh body 730 .

According to the structure as described above, the upper end of the through hole 160 surrounds the periphery of the inlet 722 , and accordingly, the LNG passing through the flow path 150 flows to the inlet 722 of the nozzle 700 . By being able to prevent the direct passage, not only foreign substances can be more smoothly filtered, but also the nozzle 700 , in particular, the mesh body 730 is protected, thereby improving the lifespan of the nozzle 700 .

Hereinafter, another embodiment of the nozzle will be described with further reference to FIGS. 6 and 7 , but the same reference numerals are assigned to the same components as the nozzles of the above-described embodiment, and repeated description thereof will be omitted.

Figure 6 is a bottom perspective view showing another embodiment of the nozzle in the LNG pump of the present invention, Figure 7 is a bottom view showing another embodiment of the nozzle in the LNG pump of the present invention.

As shown in FIGS. 6 and 7 , according to the nozzle 700 according to another embodiment of the present invention, a plurality of the discharge ports 711 are arranged on a pitch circle centered on the center of the head part 712 . are formed to inject LNG toward the rolling elements of the bearing 600, respectively.

That is, each of the discharge ports 711 is configured to evenly spray LNG from the bearing 600 toward the plurality of balls or rollers constituting the rolling element, thereby enabling the bearing 600 to be lubricated and cooled more efficiently.

In addition, as shown in FIG. 7 , according to the nozzle 700 according to another embodiment of the present invention, each of the discharge ports 711 is formed through a tangential direction of the head portion 712 when viewed in a plan view. In addition, at this time, each of the discharge ports 711 is formed to inject LNG in a direction opposite to the rotation direction when the nozzle 700 is screwed into the through hole 160 . According to such a structure, a rotational force is generated in the nozzle 700 in a direction in which the through-hole 160 is screwed to the through hole 160 by the discharge pressure of the LNG, so that the nozzle 700 is repeatedly subjected to vibration or impact. Separation from the through hole 160 can be prevented.

In the foregoing, the present invention has been described with reference to limited embodiments and drawings, but it will be apparent to those skilled in the art that various modifications are possible within the scope of the technical idea of the present invention. Accordingly, the protection scope of the present invention should be defined by the description of the claims and their equivalents.

100: casing 110: upper receiving part
120: lower receiving part 130: entrance
140: Exit 150: Euro
160: through hole 200: shaft
300: rotor 400: stator
500: impeller 600: bearing
700: nozzle 710: lower body
711: discharge port 712: head part
713: coupling part 714: female thread part
720: upper body 721: male thread part
722: inlet 723: step
730: mesh body

Claims (5)

The upper accommodating part 110 formed on the inner upper part, the lower accommodating part 120 formed on the inner lower part, the inlet 130 formed on the lower side of the lower accommodating part 120 to be connected to the lower accommodating part 120, the upper accommodating part a casing 100 including an outlet 140 formed on the upper side of the part 110 and a flow path 150 formed to connect the lower accommodating part 120 and the outlet 140;
a shaft 200 installed to extend vertically in the center of the upper accommodating part 110 and the lower accommodating part 120 of the casing 100;
a rotor 300 coupled to the shaft 200 so as to be disposed in the upper accommodating part 110 of the casing 100;
a stator 400 installed on the inner wall of the upper accommodating part 110 of the casing 100 so as to surround the rotor 300; and
The impeller 500 coupled to the shaft 200 so as to be disposed in the lower receiving portion 120 of the casing 100;
Between the upper receiving part 110 and the outlet 140, a through hole 160 connecting the upper receiving part 110 and the outlet 140 is formed,
A nozzle 700 is installed in the through hole 160 so that a part of the LNG that has passed through the flow path 150 is injected toward the bearing 600 mounted on the upper end of the shaft 200,
The nozzle 700 is
A head portion 712 having a discharge port 711 formed therein, a coupling portion 713 formed on an upper side of the head portion 712 and screwed to the through hole 160 , and an inner periphery of the coupling portion 713 . a lower body 710 having a female threaded portion 714 formed therein, and formed to have an upwardly open interior; and
An upper body having a male screw portion 721 coupled to the female screw portion 714 of the lower body 710, and an inlet 722 formed to be open laterally on the upper side of the male screw portion 721, the inside of which is formed to open downward. (720); LNG pump with improved lubrication and cooling performance of the bearing, characterized in that it includes.
According to claim 1,
The nozzle 700 is installed to surround the upper portion of the upper body 720 and further includes a mesh 730 for filtering foreign substances from the LNG flowing into the inlet 722,
An LNG pump with improved lubrication and cooling performance of the bearing, characterized in that a step 723 supporting the upper surface of the mesh body 730 is formed at the upper end of the upper body 720.
3. The method of claim 2,
The upper end of the through hole 160 is formed to protrude higher than the inlet 722 of the nozzle 700, and the inner periphery of the through hole 160 is formed to be spaced apart from the outer periphery of the mesh body 730, characterized in that LNG pump with improved lubrication and cooling performance of bearings.
4. The method according to any one of claims 1 to 3,
A plurality of discharge ports 711 of the nozzle 700 are arranged on a pitch circle centered on the center of the head portion 712, and are formed to respectively inject LNG toward the rolling element of the bearing 600,
Each of the discharge holes 711 penetrates in a tangential direction of the head portion 712 when viewed in a plan view, in a direction opposite to the direction in which the nozzle 700 is rotated when the nozzle 700 is screwed into the through hole 160 . An LNG pump with improved lubrication and cooling performance of the bearing, characterized in that it is formed to inject LNG.
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