Liquefied gas booster pump

Abstract

A liquefied gas booster pump (10) includes a storage tank (12) having a suction port (16a) and a delivery port (17a), a housing (22) having a liquefied gas delivery passage (25) including a suction port (26a), a delivery port (27a), and an impeller arrangement portion (28) formed therebetween, an impeller (52) arranged in the impeller arrangement portion (28), and a superconducting motor (45) having a motor shaft (49) protruding from a motor main body (46) into the impeller arrangement portion (28) and having the impeller (52) mounted thereto.

Description

Technical Field

[0001] This invention relates to a liquefied gas booster pump. Background Technology

[0002] Pumps are known to pressurize and deliver liquefied gases, such as liquid hydrogen, which have a density lower than water, at the same temperature. The pump system disclosed in Patent Document 1 comprises two pump units connected in series within a barrel capable of storing a fixed quantity of liquefied gas. Each pump unit contains a motor and a multi-stage impeller composed of multiple impellers arranged in series within its housing. This avoids insufficient power due to the multi-stage impeller configuration, enabling the pressurization and delivery of the liquefied gas.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2022-184024 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In the pump system of Patent Document 1, two pump units using multi-stage impellers are arranged inside a tank, resulting in an undesirable situation of overall system enlargement. That is, Patent Document 1 does not consider how to efficiently deliver liquefied gas while mitigating the overall pump enlargement.

[0008] The objective of this invention is to deliver liquefied gas efficiently while suppressing the overall size of the pump.

[0009] Solution for solving the problem

[0010] The liquefied gas booster pump of the present invention comprises: a storage tank having an inlet and an outlet, and storing liquefied gas drawn in from the inlet; a housing disposed within the storage tank and having a liquefied gas delivery passage, the liquefied gas delivery passage including an inlet opening facing into the storage tank, an outlet communicating with the outlet, and an impeller mounting portion formed between the inlet and the outlet; and an impeller disposed within the impeller mounting portion and configured to, upon rotation, deliver the liquefied gas from the storage tank through the liquefied gas delivery passage. Liquefied gas is drawn in through the inlet and discharged through the outlet; and a superconducting motor having a motor body disposed within the housing and a motor shaft protruding from the motor body toward the impeller configuration and for rotating the impeller, wherein the housing is formed with: a motor configuration axially adjacent to the impeller configuration on the motor shaft and serving as a space for arranging the motor body; and a cooling flow path spatially communicating with the storage tank and the motor configuration, and for cooling the superconducting motor using the liquefied gas.

[0011] In a first embodiment, a liquefied gas booster pump is provided, wherein the suction port of the liquefied gas delivery path is disposed between the impeller configuration and the motor configuration, and the cooling flow path has: a first inflow portion communicating with the motor configuration and opening in a manner facing into the storage tank; and a first outflow portion communicating between the motor configuration and a position in the liquefied gas delivery path upstream of the impeller configuration.

[0012] In the second embodiment, a liquefied gas booster pump is provided, wherein the suction port of the liquefied gas delivery path is disposed between the impeller configuration and the motor configuration, and the cooling flow path has: a first inflow portion that connects the motor configuration to a position in the liquefied gas delivery path upstream of the impeller configuration; and a first outflow portion that connects to the motor configuration and opens toward the storage tank.

[0013] In the third embodiment, a liquefied gas booster pump is provided, wherein the suction port of the liquefied gas delivery path is disposed between the impeller configuration and the motor configuration, and the cooling flow path has a first inflow portion and a first outflow portion that communicate with the motor configuration and open toward the storage tank.

[0014] In the fourth embodiment, a liquefied gas booster pump is provided, wherein the motor shaft protrudes bidirectionally from the motor body, the impeller configuration includes a first configuration portion and a second configuration portion arranged axially spaced apart from each other on the motor shaft, the impeller includes a first impeller disposed in the first configuration portion and a second impeller disposed in the second configuration portion, the motor configuration portion is disposed between the first configuration portion and the second configuration portion, the cooling flow path has: a first inflow portion communicating with the first configuration portion and allowing the motor configuration portion to communicate with the storage tank via the liquefied gas outlet path; and a first outflow portion communicating with both the motor configuration portion and the second configuration portion, wherein the housing has: a bearing configuration portion being a space disposed on the opposite side of the motor configuration portion relative to the second configuration portion and used for arranging a bearing; a second inflow portion communicating with the bearing configuration portion within the liquefied gas outlet path; and a second outflow portion communicating with the storage tank within the bearing configuration portion.

[0015] In the fifth embodiment, a liquefied gas booster pump is provided, wherein the cooling flow path has: an inflow section communicating with the impeller configuration section and allowing the motor configuration section to communicate with the storage tank via the liquefied gas outlet section; and a return flow path having one end connected to the motor configuration section and the other end connected to the impeller configuration section, and for allowing the liquefied gas to return directly from the motor configuration section to the impeller configuration section.

[0016] When using a conventional motor (a common three-phase motor) as a drive source to deliver liquefied gases such as liquid hydrogen, which are at a lower temperature than water, magnetic flux linkage is difficult to achieve, making it difficult to generate an induced electromotive force. This results in difficulty in rotation and thus, starting is challenging. Furthermore, due to heat loss, the liquefied gas may heat up and vaporize, leading to reduced efficiency in delivering the liquefied gas. Here, "lower temperature than water" means that, at the same pressure, the temperature at which it can maintain a liquid state is lower than that of water.

[0017] In this design, a superconducting motor, which has higher efficiency than a conventional motor, is used as the drive source, thus enabling the efficient delivery of liquefied gas. Furthermore, it suppresses the vaporization of the liquefied gas caused by heat loss. Moreover, compared to the case of configuring two pump units using a conventional motor, the axial length of the motor shaft can be shortened, allowing for overall miniaturization.

[0018] Invention Effects

[0019] In this invention, liquefied gas can be delivered efficiently while suppressing the overall size of the pump. Attached Figure Description

[0020] Figure 1This is a schematic diagram of a hydrogen receiving device using the liquefied gas booster pump of the present invention.

[0021] Figure 2 This is a cross-sectional view of the liquefied gas booster pump according to the first embodiment.

[0022] Figure 3 yes Figure 2 An enlarged cross-sectional view of the outflow section.

[0023] Figure 4 This is a cross-sectional view of the liquefied gas booster pump according to the second embodiment.

[0024] Figure 5 This is a cross-sectional view of the liquefied gas booster pump according to the third embodiment.

[0025] Figure 6 This is a cross-sectional view of the liquefied gas booster pump according to the fourth embodiment.

[0026] Figure 7 This is a cross-sectional view of the liquefied gas booster pump according to the fifth embodiment.

[0027] Figure 8 This is a cross-sectional view of the liquefied gas booster pump according to the sixth embodiment.

[0028] Figure 9 This is a cross-sectional view of the liquefied gas booster pump according to the seventh embodiment.

[0029] Figure 10 It is shown Figure 9 An enlarged sectional view of a portion of the document.

[0030] Figure 11 This is a cross-sectional view of the liquefied gas booster pump according to the eighth embodiment.

[0031] Figure 12 This is a cross-sectional view of the liquefied gas booster pump according to the ninth embodiment.

[0032] Figure 13 This is a cross-sectional view showing a portion of the liquefied gas booster pump according to the tenth embodiment.

[0033] Figure 14 This is a cross-sectional view showing a portion of the liquefied gas booster pump according to the eleventh embodiment.

[0034] Figure 15 This is a cross-sectional view of the liquefied gas booster pump according to the twelfth embodiment.

[0035] Figure 16 This is a cross-sectional view of the liquefied gas booster pump according to the thirteenth embodiment.

[0036] Figure 17 This is a cross-sectional view of the liquefied gas booster pump according to the fourteenth embodiment.

[0037] Figure 18 This is a cross-sectional view of the liquefied gas booster pump according to the fifteenth embodiment.

[0038] Figure 19 This is a cross-sectional view of the liquefied gas booster pump according to the sixteenth embodiment.

[0039] Figure 20 This is a cross-sectional view of the liquefied gas booster pump according to the seventeenth embodiment.

[0040] Figure 21 This is a cross-sectional view of the liquefied gas booster pump according to the eighteenth embodiment.

[0041] Figure 22 This is a cross-sectional view of the liquefied gas booster pump according to the nineteenth embodiment. Detailed Implementation

[0042] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0043] The liquefied gas booster pump (hereinafter referred to as "pump") 10 of the present invention is used, for example, for... Figure 1 The hydrogen receiving device 1 shown supplies liquefied hydrogen from storage tank 2 to gas turbine 4 via vaporizer 3. However, pump 10 can also be used as a tank discharge device other than hydrogen receiving device 1, and can be used for fuel supply to aircraft and ships. In addition, pump 10 can also deliver liquefied gases other than liquefied hydrogen.

[0044] The liquefied gases that can be pumped by pump 10 include, in addition to liquefied hydrogen, liquefied helium, liquefied neon, liquefied nitrogen, liquefied argon, liquefied natural gas, liquefied carbon dioxide, liquefied petroleum gas, and liquefied ammonia. Compared to water, these liquefied gases are at lower temperatures, have lower boiling points, and lower viscosity and density. Specifically, liquefied helium has a boiling point of -269°C, liquefied hydrogen -253°C, liquefied neon -246°C, liquefied nitrogen -196°C, liquefied argon -186°C, liquefied natural gas -162°C, liquefied carbon dioxide -78°C, liquefied petroleum gas -42°C, and liquefied ammonia -33°C.

[0045] (First Implementation)

[0046] When reference Figure 2 In the first embodiment, the pump 10 consists of a tank (storage tank) 12 for storing a certain amount of liquefied gas and a pump unit 20 disposed in the tank 12, which delivers the liquefied gas in the tank 12 without vaporizing it.

[0047] The container 12 has a cylindrical outer peripheral wall 13, a bottom wall 14 that closes the lower end of the outer peripheral wall 13, and a top wall 15 that closes the upper end of the outer peripheral wall 13. The container 12 is a structure in which at least the top wall 15 is formed separately from the outer peripheral wall 13 and they are liquid-tightly joined. However, the outer peripheral wall 13 can also be a polygonal cylindrical shape, and the container 12 can simply be a structure that closes both ends of the cylindrical outer peripheral wall 13. Furthermore, the amount of liquefied gas stored in the container 12 is such that the liquid level is above the inlet 16a. Additionally, as long as the liquefied gas in the container 12 does not leak out, the upper end of the outer peripheral wall 13 can also be open.

[0048] A cylindrical intake portion 16 protruding radially outward is provided on the outer peripheral wall 13. A cylindrical discharge portion 17 protruding outward along the axis A of the outer peripheral wall 13 (barrel 12) is provided on the top wall 15. The outer end opening of the intake portion 16 forms an intake port 16a, for example, with... Figure 1 The storage tank 2 shown is connected and can draw liquefied gas into the container 12. The outer end opening of the delivery section 17 forms a delivery outlet 17a, for example, connected to... Figure 1 The vaporizer 3 shown is connected. However, the cylindrical intake section 16 and outlet section 17 may be omitted, with the intake 16a directly disposed on the outer peripheral wall 13 and the outlet 17a directly disposed on the top wall 15. Alternatively, the intake section 16 may be disposed on the top wall 15, and its location can be changed as needed, as long as liquefied gas can be taken in. Similarly, the outlet section 17 may be disposed on the outer peripheral wall 13, and its location can be changed as needed, as long as liquefied gas can be discharged. Furthermore, for maintainability, it is preferable to provide a valve for discharging residual liquefied gas and a valve for discharging air in the tank 12. However, if the intake section 16 and outlet section 17 are disposed on the top wall 15, the air discharge valve is not required.

[0049] Next, when referring to Figure 2 At this time, the pump unit 20 is composed of a vertical shaft, turbine-type multi-stage diffusion pump. The pump unit 20 has a housing 22 forming a liquefied gas delivery path 25, a motor mounting section 30, and a cooling flow path 31. In addition, the pump unit 20 includes a superconducting motor 45, an impeller 52, and multiple bearings 55, 56, and 57 disposed within the housing 22.

[0050] In this embodiment, the pump unit 20 is immersed in liquefied gas in the tank 12. The liquefied gas in the tank 12 is pressurized and sent out from the outlet 17a by the rotation of the impeller 52 driven by the superconducting motor 45.

[0051] First, let’s describe the structure other than the shell 22.

[0052] The superconducting motor 45 includes a motor body 46 and a motor shaft 49, and has a higher output density per unit mass compared to a conventional motor (a common three-phase motor). This allows for a reduction in the mass of the rotor 48 within the motor body 46, improving the characteristic values ​​of all rotating parts, including the impeller 52 and the rotor 48, thus making it suitable for high-speed rotation. In this embodiment, a superconducting motor 45 with a constant rotational speed (fixed speed) for the motor shaft 49 is used. However, the superconducting motor 45 could also be a structure where the rotational speed of the motor shaft 49 can be varied by inverter control.

[0053] The motor body 46 is mounted within the motor mounting section 30 of the housing 22. The motor body 46 includes a cylindrical stator 47 fixed to the motor housing 22 and a cylindrical rotor 48 disposed within the stator 47. The superconducting motor 45 of this embodiment consists of a stator 47 with the same structure as the stator of a conventional motor and a rotor 48 using superconducting wire. For example, the stator 47 has the same structure as a squirrel-cage induction motor, and a rotating magnetic field is generated by the magnetic field formed by the coils being synchronized with the AC power supply. The rotor 48 is a structure in which superconducting wire is electrically connected to a conductor rod and an end ring, and rotates under the action of the rotating magnetic field of the stator 47. However, a fully superconducting motor in which both the stator 47 and the rotor 48 use superconducting wire can also be applied to the superconducting motor 45.

[0054] The motor shaft 49 is mounted relative to the rotor 48 of the motor body 46 in a manner that prevents relative movement in both the circumferential and axial directions, and protrudes upward and downward (bidirectionally) from the motor body 46. The downward-protruding main portion 49a of the motor shaft 49 protrudes into the impeller configuration portion 28 of the liquefied gas outlet passage 25 of the housing 22. The upward-protruding secondary portion 49b of the motor shaft 49 protrudes into the bearing configuration portion 34 of the cooling flow passage 31 of the housing 22. The axis (axial direction) of the motor shaft 49, the axis of the housing 22, and the axis A of the barrel 12 are aligned. That is, the motor shaft 49 extends along axis A, and the axial direction of the motor shaft 49 is aligned with axis A.

[0055] The impeller 52 rotates integrally with the motor shaft 49, and the impeller 52 draws liquefied gas from the tank 12 into the liquefied gas outlet 25 of the housing 22 and discharges it from the outlet 17a. The impeller 52 is disposed in the impeller mounting section 28 of the housing 22 located below the motor body 46, and is mounted so as not to move relative to the main part 49a of the motor shaft 49 in either the circumferential or axial directions. In this embodiment, the impeller 52 is composed of a multi-stage impeller consisting of multiple (10 in this embodiment) closed impellers 53 arranged in series in a single-suction type, spaced apart in the axial direction of the motor shaft 49. The number of closed impellers 53 can be varied depending on the liquefied gas being discharged.

[0056] Multiple bearings 55, 56, and 57 are mounted spaced apart from the housing 22 along the axial direction of the motor shaft 49, supporting the motor shaft 49 for rotation. In this embodiment, one magnetic bearing (axial bearing) 55, one touchdown bearing 56 consisting of rolling bearings, and three rolling bearings (radial bearings) 57 are used. In the following description, the three rolling bearings 57 are sometimes referred to as rolling bearings 57A, 57B, and 57C sequentially from top to bottom. However, the number of magnetic bearings 55 and rolling bearings 57 can be varied as needed. On the other hand, it is preferable that there are two or fewer magnetic bearings 55 and more than two rolling bearings 57. Furthermore, the arrangement of magnetic bearings 55 and rolling bearings 57 can be varied as needed.

[0057] A magnetic bearing 55 is disposed within a bearing mounting section 34 of the housing 22 located above the motor body 46, and supports the sub-section 49b of the motor shaft 49. The magnetic bearing 55 is disposed on the side opposite to the motor body 46 relative to the rolling bearing 57A. The magnetic bearing 55 is an axial bearing comprising a base plate and an electromagnet, and bearing the axial load of the motor shaft 49 in a non-contact manner. The base plate is made of a strongly magnetic metal and is mounted so as not to move relative to the sub-section 49b of the motor shaft 49 in either the circumferential or axial directions. The electromagnet is mounted in the bearing mounting section 34 at intervals relative to the base plate in the axial direction of the motor shaft 49. However, a superconducting magnetic bearing using a superconducting coil as the electromagnet may also be used in the magnetic bearing 55. Alternatively, a permanent magnet may be used instead of an electromagnet. Alternatively, a rolling bearing or a sliding bearing capable of providing axial support may be used instead of the magnetic bearing 55. Furthermore, other components may be sandwiched between the magnetic bearing 55 and the rolling bearing 57A.

[0058] The bottom-contact bearing 56 and the rolling bearing 57 each include: an inner ring, which is mounted relative to the motor shaft 49 in both the circumferential and axial directions without relative movement; an outer ring, which is mounted on the housing 22; and a plurality of rolling elements, which are rotatably disposed between the inner and outer rings. The bottom-contact bearing 56 is an axial bearing that bears the axial load of the motor shaft 49, and the rolling bearing 57 is a radial bearing that bears the radial load of the motor shaft 49.

[0059] The bottom bearing 56 is positioned above the magnetic bearing 55 and supports the front end of the sub-section 49b of the motor shaft 49. This bottom bearing 56 prevents the substrate from contacting the electromagnet when the magnetic bearing 55 is not in operation, and functions as a fail-safe device to prevent damage to the magnetic bearing 55.

[0060] Rolling bearing 57A is positioned between the motor body 46 and the magnetic bearing 55, supporting the base end of the secondary portion 49b of the motor shaft 49. Rolling bearing 57B is positioned between the motor body 46 and the impeller 52, supporting the base end of the main portion 49a of the motor shaft 49. Rolling bearing 57C is positioned below the impeller 52, supporting the front end of the main portion 49a of the motor shaft 49. However, if the analytical results of the natural frequencies and displacements of all rotating bodies, including the impeller 52 and the rotor 48, are satisfactory, rolling bearing 57C may sometimes be unnecessary. Alternatively, magnetic bearings or sliding bearings capable of radial support may be used instead of rolling bearing 57.

[0061] An inducer 58 is disposed between the rolling bearing 57C and the impeller 52. The inducer 58 is mounted relative to the front end of the main portion 49a in the motor shaft 49 in both the circumferential and axial directions without relative movement, and rotates integrally with the motor shaft 49. This facilitates the intake of liquid by the impeller 52. However, if the amount of liquid intake by the impeller 52 can be ensured, the inducer 58 may not be required.

[0062] As described above, in the structure where the impeller 52 is arranged on the motor shaft 49 of the superconducting motor 45, the motor efficiency of the superconducting motor 45 is high, thereby enabling the efficient delivery of liquefied gas and suppressing the vaporization of liquefied gas caused by heat loss. The magnetic bearing 55 requires a control unit 60 to control the magnetic force, but it can support the motor shaft 49 non-contactly without wear, thus allowing for semi-permanent use. The rolling bearing 57, unlike the magnetic bearing 55, does not require a control unit, thus reducing the manufacturing cost of the pump 10. In this embodiment, the use of both the magnetic bearing 55 and the rolling bearing 57 minimizes cost increases and improves support performance. Furthermore, if a superconducting magnetic bearing is used as the magnetic bearing 55, a strong repulsive levitation force can be achieved through the pinning effect of the magnetic flux.

[0063] The pump 10 of this embodiment includes a control unit 60 for controlling the superconducting motor 45 and the magnetic bearing 55. The control unit 60 is constructed from hardware including a storage device such as a CPU (Central Processing Unit), RAM (Random Access Memory), and ROM (Read Only Memory) and software installed on the hardware. However, the superconducting motor 45 and the magnetic bearing 55 may also be controlled independently by separate control units.

[0064] The control unit 60, for example, operates an operation unit (not shown) performed by an operator to rotate the motor shaft 49 of the superconducting motor 45 at a specified speed. Furthermore, the control unit 60 controls the magnetic bearing 55 based on the detection results of a ranging sensor (detection unit) 61 that detects the end position of the motor shaft 49, i.e., the amount of axial movement of the motor shaft 49. Specifically, the control unit 60 adjusts the amount of current energized to the electromagnet of the magnetic bearing 55, thereby adjusting the axial support force on the motor shaft 49 provided by the magnetic bearing 55, and thus confining the motor shaft 49 and the rotor 37 of the balance piston 35 (described in detail later) to a defined position. However, the magnetic bearing, including the superconducting magnetic bearing, is not limited to an active type and can also be passive. Additionally, the superconducting motor 45 may also have a structure equipped with an axial balancing mechanism.

[0065] Next, the structure of the housing 22 will be described in detail.

[0066] Next, when referring to Figure 2 At this time, the housing 22 is fixed to the top wall 15 of the barrel 12 and hangs down along the axis A of the barrel 12. The housing 22 has a liquefied gas outlet 25, a motor mounting section 30 and a cooling flow path 31 as described above.

[0067] The liquefied gas delivery path 25 includes an intake section 26, an exhaust section 27, and an impeller mounting section 28, and extends from the lower end to the upper end of the housing 22.

[0068] The suction section 26 is located at the lower end of the housing 22 and protrudes downward in a cylindrical shape. The lower opening of the suction section 26 forms a suction port 26a for drawing in liquefied gas from the container 12. The suction port 26a is located above the bottom wall 14 of the container 12 at intervals and opens towards the inside of the container 12. However, the cylindrical suction section 26 may be omitted, and the suction port 26a may be directly located at the lower end of the housing 22.

[0069] A rolling bearing 57C and an inducer 58 are provided within the suction section 26. The rolling bearing 57C divides the impeller configuration section 28 relative to the inside of the container 12. The impeller configuration section 28 and the inside of the container 12 are spatially connected via the rolling bearing 57C. In this embodiment, a connecting hole 26b is provided in the mounting seat of the rolling bearing 57C within the suction section 26. This connecting hole 26b ensures the intake amount of liquefied gas into the liquefied gas delivery path 25.

[0070] The discharge section 27 is located on the upper part of the housing 22 and communicates with the suction section 26 via the impeller mounting section 28. The discharge section 27 is connected to the upper outer periphery of the impeller mounting section 28 and extends upward around the motor mounting section 30 and the cooling flow path 31. The upper end of the discharge section 27 is a discharge port 27a for discharging liquefied gas. The discharge port 27a opens on axis A at the upper end of the housing 22, located directly below the delivery section 17 of the tank 12. Thus, the discharge port 27a communicates with the delivery port 17a.

[0071] The impeller configuration section 28 is connected to the upper end of the suction section 26 including the suction port 26a and the lower end of the discharge section 27 including the discharge port 27a, and extends along the axis A. Multiple partition walls 28a are provided in the impeller configuration section 28 in an annular shape to separate adjacent enclosed impellers 53 in the impeller 52.

[0072] By configuring the liquefied gas delivery path 25 in this way, the liquefied gas in the tank 12 is drawn in from the suction port 26a under the action of the rotation of the impeller 52 and the inducer 58 driven by the superconducting motor 45. Next, the liquefied gas passes sequentially through the suction section 26, the impeller arrangement section 28, and the discharge section 27 and is discharged from the discharge port 27a. Afterward, the liquefied gas is discharged from the discharge port 17a through the delivery section 17.

[0073] The motor mounting section 30 is a space for mounting the motor body 46 of the superconducting motor 45. The motor mounting section 30 is disposed in the housing 22 between the upper and lower ends of the discharge section 27 and extends along axis A. That is, the motor mounting section 30 is disposed adjacent to the impeller mounting section 28 on the upper side of the side that serves as the discharge port 27a.

[0074] A rolling bearing 57B is disposed between the motor mounting section 30 and the impeller mounting section 28. In other words, the rolling bearing 57B is disposed on the impeller mounting section 28 side of the motor mounting section 30. The rolling bearing 57B separates the motor mounting section 30 and the impeller mounting section 28. The motor mounting section 30 and the impeller mounting section 28 are spatially connected via the rolling bearing 57B.

[0075] The cooling flow path 31 spatially connects the interior of the tank 12 with the interior of the motor mounting section 30, and is provided for directly cooling the superconducting motor 45 using liquefied gas. The cooling flow path 31 consists of an inlet section 32, an outlet section 33, and a bearing mounting section 34. The inlet section 32 is indirectly connected to the interior of the tank 12 via the liquefied gas delivery path 25, and the outlet section 33 is directly connected to the interior of the tank 12.

[0076] An inlet section 32 is disposed between the motor mounting section 30 and the impeller mounting section 28. The inlet section 32 opens towards the discharge portion 28f of the impeller mounting section 28 and communicates with the interior of the container 12 via the impeller mounting section 28 and the suction portion 26 of the liquefied gas delivery path 25. Furthermore, the inlet section 32 communicates with the interior of the motor mounting section 30. Thus, the interior of the container 12 is connected to the interior of the motor mounting section 30 via the inlet section 32, the impeller mounting section 28, and the suction portion 26. More specifically, the inlet section 32 communicates with the discharge portion 28f, which is downstream of the impeller mounting section 28 in the direction of liquefied gas delivery. A balance piston 35, which will be described in detail later, is disposed within the inlet section 32.

[0077] The outlet 33 is disposed on the upper side opposite to the inlet 32, relative to the motor mounting section 30. The outlet 33 communicates with the motor mounting section 30 via the bearing mounting section 34. The outlet 33 opens on the outer peripheral surface of the housing 22 facing inwards towards the inside of the barrel 12. More specifically, as Figure 3 As shown, the outlet 33 has a first portion 33a extending along axis A and a second portion 33b extending in a direction intersecting (orthogonal) with the first portion 33a and facing into the barrel 12. A throttling orifice 39, which will be described in detail later, is provided at the outlet of the outlet 33.

[0078] When reference Figure 2 At this time, the bearing mounting section 34 is a space for mounting the magnetic bearing 55. The bearing mounting section 34 is provided between the motor mounting section 30 and the outlet section 33, and extends along axis A. That is, the bearing mounting section 34 is located between the inlet section 32 and the outlet section 33, and is located on the side opposite to the impeller mounting section 28 relative to the motor mounting section 30. The bearing mounting section 34 is connected to both the motor mounting section 30 and the outlet section 33. The magnetic bearing mounted in the bearing mounting section 34 is not limited to a magnetic bearing 55 that can support the motor shaft 49 in the axial direction. If an axial bearing is mounted in a part other than the bearing mounting section 34, it may also be a structure that can support the motor shaft 49 in the radial direction.

[0079] A rolling bearing 57A is disposed between the bearing mounting section 34 and the motor mounting section 30. In other words, the rolling bearing 57A is disposed on the bearing mounting section 34 side of the motor mounting section 30. The rolling bearing 57A separates the bearing mounting section 34 from the motor mounting section 30. The bearing mounting section 34 and the motor mounting section 30 are spatially connected via the rolling bearing 57A.

[0080] A recessed portion 34a is provided at the upper end of the bearing mounting portion 34, which is upwardly recessed and accommodates the upper end of the motor shaft 49. A bottom-contact bearing 56 is disposed within the recessed portion 34a, and a ranging sensor 61 for detecting the upper end of the motor shaft 49 is also disposed therewith. However, the ranging sensor 61 may also be provided by the magnetic bearing 55 itself.

[0081] The balancing piston 35 is a balancing device disposed within the inlet section 31, adjusting the inflow of liquefied gas into the cooling flow path 31, including the motor mounting section 30, and reducing shaft thrust by depressurization. The balancing piston 35 includes a mounting base 36 and a rotor 37. The gap and shape between the mounting base 36 and the rotor 37 are set in such a way that the pressure difference (differential pressure) between the internal pressure of the discharge section 28f in the liquefied gas outlet path 25, more specifically the discharge pressure of the impeller 52, and the internal pressure of the cooling flow path 31, including the motor mounting section 30, is within an appropriate range. The balancing piston 35 also functions as a pressure-reducing element on the low-pressure side. In this embodiment, a single balancing piston is used in the balancing piston 35. However, in a balancing device, a double balancing piston may be used instead of the balancing piston 35.

[0082] The mounting base 36 is cylindrically mounted on the inner circumference of the inlet portion 32, with its center aligned with axis A. The internal space defined by the inner circumferential surface of the mounting base 36 functions as a communication hole that connects the impeller mounting portion 28 with the motor mounting portion 30. The lower end of the communication hole opens towards the discharge portion 28f of the impeller mounting portion 28, and the upper end of the communication hole opens towards the motor mounting portion 30.

[0083] The rotor 37 is cylindrically mounted relative to the motor shaft 49 in both the circumferential and axial directions and is disposed within the internal space of the mounting base 36. Under the influence of the differential pressure between the liquefied gas delivery path 25 and the cooling flow path 31, including the motor mounting section 30, the rotor 37 can move integrally with the motor shaft 49 along axis A.

[0084] The balancing piston 35 restricts the inflow of liquefied gas from the discharge portion 28f of the liquefied gas outlet 25 into the cooling flow path 31, and allows the inflow of liquefied gas from the liquefied gas outlet 25 into the cooling flow path 31 by utilizing the gap (i.e., the opening area) between the inner circumferential surface of the mounting base 36 and the outer circumferential surface of the rotor 37. The load supporting the rotor 37 is obtained under the pressure difference between the upstream and downstream sides of the balancing piston 35. Furthermore, excessive movement of the rotor 37 along the axis A is limited, as described above, by the control unit 60 through the control of the magnetic bearing 55 based on the detection results of the ranging sensor 61.

[0085] When reference Figure 2 as well as Figure 3At this time, the throttling orifice 39 is disposed at the outlet portion of the outflow section 33, and maintains the pressure in the cooling flow path 31, including the motor mounting section 30, at a higher pressure than that in the tank 12. More specifically, a threaded groove is provided at the outlet portion of the outflow section 33, and a bolt 40 with a through hole is screwed into the threaded groove. The through hole of the bolt 40 is smaller than the inner diameter of the second portion 33b of the outflow section 33, and constitutes the throttling orifice 39 as a pressure reducing device. However, the pressure reducing device is not limited to the throttling orifice 39 with the same cross-sectional shape. It can also be a Venturi structure with a gradually decreasing cross-sectional shape from the upstream side to the downstream side in the flow direction, or it can be constituted by an on / off valve, or it can be constituted by a labyrinth. In addition, the pressure reducing device can be constituted by a multi-stage throttling orifice arranged in series at intervals. If the pressure reducing device is constituted by a multi-stage throttling orifice, the pressure in the cooling flow path 31 can be reliably maintained at a higher pressure than that in the tank 12.

[0086] In the cooling flow path 31 configured as described above, when the liquefied gas in the tank 12 is discharged through the liquefied gas discharge path 25 by the rotation of the impeller 52 driven by the superconducting motor 45, a portion of the discharged liquefied gas flows into the inlet 32 ​​through the balance piston 35 under the action of the discharge pressure of the impeller 52. Furthermore, the inflowing liquefied gas flows out (returns) into the tank 12 through the rolling bearing 57B, the motor mounting section 30, the rolling bearing 57A, the bearing mounting section 34, and the outlet 33. Therefore, the superconducting motor 45, the magnetic bearing 55, and the rolling bearing 57 can be reliably cooled through heat exchange. Additionally, the outflow of liquefied gas into the tank 12 is suppressed by the throttling orifice 39. Therefore, the cooling flow path 31, including the motor mounting section 30, can be pressurized, and the vaporization of the liquefied gas can be suppressed.

[0087] In the pump 10 with the structure described above, the tank 12 is filled with liquefied gas. Therefore, when a conventional motor is used as the drive source for delivering the liquefied gas, magnetic flux linkage is difficult to achieve, making it difficult to generate an induced electromotive force. Consequently, rotation is difficult, resulting in starting difficulties. Furthermore, due to the heat loss generated, the liquefied gas may heat up and vaporize, leading to a decrease in the efficiency of delivering the liquefied gas.

[0088] On the other hand, to pressurize the liquefied gas to a pressure equivalent to that of water, it is necessary to increase the number of stages of the enclosed impeller 53 constituting the impeller 52, reduce the specific speed, or increase the rotation speed. However, increasing the number of stages of the impeller 52 increases the length of the motor shaft 49, which may lead to concerns about increased costs and vibration. Furthermore, reducing the specific speed may result in decreased efficiency and concerns about boil-off gas (BOG). Additionally, increasing the rotation speed may lead to concerns about increased vibration and resonance.

[0089] In contrast, in the pump 10 of this embodiment, a superconducting motor 45 is used as the drive source. The superconducting motor 45 is cooled to a low temperature, reducing the resistance of the superconducting wire to zero and minimizing losses, thus enabling normal operation. Furthermore, since the superconducting motor 45 can rotate at high speeds compared to conventional motors, there is no need to increase the number of impeller stages 52. Additionally, high output density can be achieved, allowing for motor miniaturization. Therefore, while suppressing overall size increases, liquefied gas can be delivered efficiently, and BOG (bulk air gap) can be suppressed. Moreover, a magnetic bearing 55 is used in one of the multiple bearings. This reduces vibration and maintenance costs.

[0090] More specifically, the liquefied gas booster pump 10 of this embodiment has the following features.

[0091] A superconducting motor 45, which is more efficient than a conventional motor, is used as the drive source. This allows for the efficient delivery of liquefied gas. Furthermore, it suppresses the vaporization of the liquefied gas caused by heat loss. Moreover, compared to the case where two pump units using a conventional motor are configured, the axial length of the motor shaft 49 can be shortened, enabling overall miniaturization. Additionally, since the tank 12 is filled with liquefied gas and the housing 22, including the superconducting motor 45, is submerged, the superconducting motor 45 can be maintained in a superconducting state.

[0092] A cooling flow path 31 is formed in the housing 22 to spatially communicate with the interior of the barrel 12 and the motor mounting section 30, and to cool the superconducting motor 45 using liquefied gas. Therefore, by direct cooling with liquefied gas, the superconducting motor 45 can be reliably maintained in a superconducting state.

[0093] The cooling flow path 31 has an inflow section 32 that communicates with the discharge section 28f of the impeller configuration section 28. This allows liquefied gas to be supplied to the cooling flow path 31 under the discharge pressure of the impeller 52. Therefore, the superconducting motor 45 can be reliably cooled using liquefied gas.

[0094] The bearing mounting section 34 is located on the side opposite to the impeller mounting section 28, opposite to the motor mounting section 30, and is connected to both the motor mounting section 30 and the outlet section 33. Furthermore, a magnetic bearing 55 for supporting the motor shaft 49 is mounted on the bearing mounting section 34. Therefore, the magnetic bearing 55, which heats up due to the rotation of the motor shaft 49, can be cooled using liquefied gas.

[0095] The bearings supporting the motor shaft 49 utilize both magnetic bearings 55 and rolling bearings 57, thus minimizing cost increases and enabling high-speed rotation of the motor shaft 49 with low vibration. Furthermore, losses caused by sliding contact, i.e., wear and heat generation, are suppressed, thereby preventing the vaporization of liquefied gas and efficiently delivering it. Additionally, by arranging multiple rolling bearings 57A-57C, the intervals supporting the motor shaft 49 can be shortened, thereby improving shaft rigidity, increasing the resonant frequency, and suppressing resonance.

[0096] By using a superconducting magnetic bearing as the magnetic bearing 55, a strong repulsive levitation force can be achieved through the pinning effect of the magnetic flux. Therefore, non-contact support of the motor shaft 49 in a controlless state is possible, thereby enabling a structure that minimizes bearing losses.

[0097] A throttling orifice 39 is provided in the outlet 33 to maintain a higher pressure in the cooling flow path 31 compared to the tank 12. This suppresses the vaporization of liquefied gas in the cooling flow path 31. Furthermore, by utilizing a multi-stage throttling orifice system comprising multiple throttling orifices 39 to create damping, the pressure in the cooling flow path 31 can be reliably maintained at a higher level than that in the tank 12.

[0098] A balancing piston 35 is disposed in the inlet section 32 constituting the cooling flow path 31. This allows the flow rate of liquefied gas from the outlet section 28f of the liquefied gas outlet 25 into the cooling flow path 31 to be adjusted using the pressure difference between the outlet section 28f and the cooling flow path 31. Furthermore, the balancing piston 35 can receive an axial load from the upstream high-pressure side to the downstream low-pressure side. This axial load is generated in the opposite direction to the axial load caused by hydraulic force, thus reducing the axial load on the pump.

[0099] The impeller 52 is a multi-stage impeller consisting of multiple enclosed impellers 53 connected in series. Therefore, it can efficiently deliver liquids at a pressure equivalent to that of water.

[0100] The following describes other embodiments and various modifications of the present invention, but points not specifically mentioned in these descriptions are the same as those in the first embodiment.

[0101] In the direction of liquefied gas delivery from liquefied gas delivery path 25, Figure 2 In the pump 10 of the first embodiment shown, the superconducting motor 45 is positioned downstream of the impeller 52. Conversely, in... Figures 4 to 6In the pumps 10 of the second to fourth embodiments shown, a superconducting motor 45 is positioned upstream of the impeller 52. This configuration allows the superconducting motor 45 to be cooled by the liquefied gas immediately flowing into the housing 22. Furthermore, the superconducting motor 45 and the magnetic bearing 55 can be cooled using different cooling paths 31 and 68. The structures of the pumps 10 of the second to fourth embodiments will be described below.

[0102] (Second Implementation)

[0103] When reference Figure 4 In the second embodiment, the pump 10 is arranged from bottom to top along axis A in the order of superconducting motor 45, impeller 52, and magnetic bearing 55. Rolling bearings 57 are arranged above and below the superconducting motor 45, respectively. In addition, an inducer 58 is arranged upstream of the impeller 52 in the liquid delivery path 25, and an axial flow impeller 65 is arranged between the inducer 58 and the motor body 46 of the superconducting motor 45.

[0104] The superconducting motor 45 is configured such that the main portion 49a of the motor shaft 49 protrudes upward from the motor body 46, and the secondary portion 49b of the motor shaft 49 protrudes downward from the motor body 46. The front end of the main portion 49a of the motor shaft 49 is supported by a magnetic bearing 55, and the base end of the main portion 49a of the motor shaft 49 is supported by a rolling bearing 57. The secondary portion 49b of the motor shaft 49 is supported by a rolling bearing 57.

[0105] The axial impeller 65 is mounted so as not to move relative to the main part 49a of the motor shaft 49. The axial impeller 65 rotates integrally with the motor shaft 49, causing the liquefied gas to flow from the bottom to the top along the axis A. However, instead of the axial impeller 65, a centrifugal impeller or a diagonal flow impeller may be used, and the type of impeller can be changed as needed.

[0106] The housing 22 is provided with a liquefied gas outlet 25 and a motor mounting section 30. In addition, the housing 22 in this embodiment is provided with a cooling flow path (first cooling flow path) 31 for cooling the superconducting motor 45 and a cooling flow path (second cooling flow path) 68 for cooling the magnetic bearing 55.

[0107] The liquefied gas delivery path 25, like in the first embodiment, includes an intake section 26, an exhaust section 27, and an impeller configuration section 28. The intake section 26 is located in the central portion of the total height of the housing 22, between the inducer 58 and the axial flow impeller 65. The intake port 26a of the intake section 26 is spaced apart and located inside the outer peripheral wall 13 of the barrel 12, opening towards the inside of the barrel 12. The intake section 26 extends radially inward from the intake port 26a located on the outer peripheral surface of the housing 22. However, the intake section 26 may also be composed of multiple through holes that radially penetrate the housing 22, or ribs may be provided within the intake section 26. The exhaust section 27 is connected to the outer peripheral portion of the exhaust portion 28f of the impeller configuration section 28 and extends upward around the cooling flow path 68. The impeller configuration section 28 communicates with the inner end of the intake section 26 including the intake port 26a and the lower end of the exhaust portion 27 including the exhaust port 27a, and extends along axis A.

[0108] The motor mounting section 30 is positioned below the suction section 26 of the liquefied gas delivery path 25 and extends along axis A. That is, the motor mounting section 30 is positioned adjacent to the impeller mounting section 28 at the suction port 26a. Rolling bearings 57 are respectively mounted above and below the motor mounting section 30.

[0109] The cooling flow path 31 consists of an inflow section (first inflow section) 32 that is directly connected to the inside of the barrel 12, an outflow section (first outflow section) 33 that is connected to the suction section 26 of the liquefied gas delivery path 25, and an axial flow impeller configuration section 66.

[0110] The inlet section 32 is located on the lower side opposite to the liquefied gas outlet path 25, opposite to the motor mounting section 30, and opens on the outer peripheral surface of the housing 22 facing inwards towards the inside of the container 12. The inlet section 32 extends radially inwards from the outer peripheral surface of the housing 22 and has an expanded portion 32a with a circular cross-section centered on axis A on its inner side. A rolling bearing 57 is disposed between the inlet section 32 and the motor mounting section 30. The rolling bearing 57 separates the inlet section 32 and the motor mounting section 30. The inlet section 32 and the motor mounting section 30 are spatially connected via the rolling bearing 57. However, the inlet section 32 may also be composed of multiple through holes that radially penetrate the housing 22, or ribs may be provided within the inlet section 32.

[0111] An outlet 33 is disposed between the intake 26 and the axial impeller configuration 66 of the liquefied gas delivery path 25. The outlet 33 opens towards the inside of the intake 26 and communicates with the upstream side of the impeller configuration 28 in the direction of liquefied gas delivery. Furthermore, the outlet 33 communicates with the motor configuration 30 via the axial impeller configuration 66. However, the outlet 33 may also be configured to communicate with the portion where the inducer 58 is located. Alternatively, the outlet 33 may be configured to communicate with the upstream side of the impeller configuration 28, which is the downstream side of the inducer 58.

[0112] The axial impeller mounting section 66 is a space for mounting the axial impeller 65, and is connected to both the outlet section 33 and the motor mounting section 30. A rolling bearing 57 is disposed between the axial impeller mounting section 66 and the motor mounting section 30. The rolling bearing 57 divides the axial impeller mounting section 66 and the motor mounting section 30. The axial impeller mounting section 66 and the motor mounting section 30 are spatially connected via the rolling bearing 57.

[0113] In the cooling flow path 31 configured as described above, the liquefied gas in the tank 12 flows in from the inlet 32 ​​under the attraction of the rotation of the impeller 52 and the inducer 58 driven by the superconducting motor 45 and the liquefied gas delivered through the liquefied gas outlet path 25. Furthermore, the liquefied gas flows out from the outlet 33 into the liquefied gas outlet path 25 via the motor mounting section 30 and the axial impeller mounting section 66. Additionally, the rotation of the axial impeller 65 driven by the superconducting motor 45 promotes the flow of liquefied gas sequentially through the inlet 32, the motor mounting section 30, the axial impeller mounting section 66, and the outlet 33 towards the liquefied gas outlet path 25.

[0114] Thus, the superconducting motor 45 is cooled efficiently by heat exchange with the unheated liquefied gas flowing in from the tank 12. Furthermore, the liquefied gas, heated by the cooling of the superconducting motor 45, is discharged into the liquefied gas outlet 25, where it is mixed with the unheated liquefied gas flowing directly from the tank 12 into the outlet 25, and then discharged out of the tank 12. Therefore, vaporization of the liquefied gas caused by temperature rise can be suppressed, and the temperature rise of the liquefied gas inside the tank 12 can also be suppressed.

[0115] However, the liquefied gas delivered by the axial impeller 65 can also be directed towards one side (lower side) of the motor body 47, and a portion of the liquefied gas drawn in from the suction section 26 can be supplied to the motor body 47. In this case, Figure 4 The outflow section 33 constitutes the inflow section. Figure 4 The portion of the inflow section 32 constitutes the outflow section.

[0116] A bearing mounting section 34, which houses the magnetic bearing 55, is disposed within the housing 22 between the upper and lower ends of the discharge section 27 and extends along axis A. Specifically, the bearing mounting section 34 is disposed adjacent to the upper side of the impeller mounting section 28, opposite to the motor mounting section 30, i.e., the side that serves as the discharge port 27a. The magnetic bearing 55 and a ranging sensor 61 are disposed within the bearing mounting section 34.

[0117] The cooling flow path 68 is provided to allow the interior of the barrel 12 to be spatially connected to the interior of the bearing mounting section 34, and to cool the magnetic bearing 55 using liquefied gas. The cooling flow path 68 consists of an inflow section (second inflow section) 69 that is indirectly connected to the interior of the barrel 12 via the liquefied gas delivery path 25, and an outflow section (second outflow section) 70 that is directly connected to the interior of the barrel 12.

[0118] An inlet section 69 is provided between the impeller configuration section 28 and the bearing configuration section 34. The inlet section 69 opens towards the discharge portion 28f of the impeller configuration section 28 and communicates with the interior of the container 12 via the liquefied gas delivery path 25. Furthermore, the inlet section 69 communicates with the interior of the bearing configuration section 34. Thus, the interior of the container 12 and the interior of the bearing configuration section 34 are connected via the inlet section 69, the impeller configuration section 28, and the suction section 26. More specifically, the inlet section 69 communicates downstream of the impeller configuration section 28 in the direction in which the liquefied gas is delivered. Therefore, liquefied gas can be supplied to the cooling flow path 68, including the impeller configuration section 28, under the action of the discharge pressure of the impeller 52. A balance piston 35 is provided in the inlet section 69. The flow rate of liquefied gas into the cooling flow path 68, including the impeller configuration section 28, is adjusted by the action of the balance piston 35.

[0119] The outlet 70 is disposed on the upper side opposite to the inlet 69, relative to the bearing mounting portion 34, and communicates with the bearing mounting portion 34. The outlet 70 opens on the outer peripheral surface of the housing 22 facing inwards towards the inside of the barrel 12. More specifically, the outlet 70 has a first portion extending along axis A and a second portion extending in a direction intersecting the first portion and facing inwards towards the inside of the barrel 12. A [missing information - likely a component or part] is disposed at the outlet portion of the outlet 70. Figure 3 The same throttling orifice 39 is shown in the first embodiment. Under the action of the throttling orifice 39, the cooling flow path 68, including the impeller configuration section 28, is maintained at a higher pressure than that inside the tank 12.

[0120] In the cooling flow path 68 configured as described above, when the liquefied gas in the tank 12 is discharged through the liquefied gas discharge path 25 by the rotation of the impeller 52 driven by the superconducting motor 45, a portion of the discharged liquefied gas flows into the inlet 69 through the balance piston 35 under the action of the discharge pressure of the impeller 52. Furthermore, the inflowing liquefied gas flows out into the tank 12 through the bearing mounting section 34 and the outlet 70. Therefore, the magnetic bearing 55 can be reliably cooled. In addition, the outflow of liquefied gas into the tank 12 is suppressed by the throttling orifice 39. Therefore, the cooling flow path 68, including the bearing mounting section 34, can be reliably pressurized.

[0121] (Third implementation method)

[0122] When reference Figure 5 At that time, the pump 10 in the third embodiment changed the structure of the cooling flow path (first cooling flow path) 31. Figure 4 The pump 10 shown in the second embodiment is different. It is not used in the cooling flow path 31 of the pump 10 in the third embodiment. Figure 4 The axial flow impeller 65 shown includes the axial flow impeller configuration section 66. Figure 5 In the middle, to and Figure 4 The same elements in the second embodiment shown are labeled with the same reference numerals.

[0123] The cooling flow path 31 is composed of a plurality of through holes that extend radially. Each through hole has an outer end that faces inward toward the inside of the barrel 12 and an inner end that faces inward toward the inside of the motor mounting section 30. A portion of the plurality of through holes thus formed constitutes an inflow section (first inflow section) 32, and the remaining portion constitutes an outflow section (first outflow section) 33.

[0124] In the cooling flow path 31 configured as described above, liquefied gas flows in and out of the motor mounting section 30 due to the temperature difference between the tank 12 and the motor mounting section 30, as well as the rotational force of the rotor 48. As a result, the superconducting motor 45 is cooled efficiently by heat exchange with the unheated liquefied gas flowing in from the tank 12. Furthermore, the liquefied gas, heated by the cooling of the superconducting motor 45, returns to the tank 12 and mixes with the unheated liquefied gas, thus suppressing vaporization caused by temperature rise. It should be noted that the flow of liquefied gas in and out of the motor mounting section 30 is based on the temperature difference and the rotational force of the rotor 48; therefore, the liquefied gas hardly flows through the rolling bearing 57 between the motor mounting section 30 and the liquefied gas outlet path 25. However, a circulation impeller can be installed in the motor mounting section 30 to ensure the circulation volume of the liquefied gas.

[0125] (Fourth Implementation)

[0126] When reference Figure 6The pump 10 of the fourth embodiment differs from the pumps 10 of the other embodiments described above in that it has a first impeller 52A and a second impeller 52B arranged at intervals along axis A, with a superconducting motor 45 arranged between them, and in that it modifies the structure of the liquefied gas delivery path 25 and the cooling flow path (first cooling flow path) 31. Figure 6 In this document, elements that are the same as those in other embodiments are labeled with the same reference numerals.

[0127] Both the first impeller 52A and the second impeller 52B are composed of multi-stage impellers. The first impeller 52A is positioned below the superconducting motor 45, and the second impeller 52B is positioned above the superconducting motor 45. The number of enclosed impellers 53 constituting the first impeller 52A is less than the number of enclosed impellers 53 constituting the second impeller 52B. In this embodiment, there are two enclosed impellers 53 constituting the first impeller 52A and four enclosed impellers 53 constituting the second impeller 52B. However, the number of enclosed impellers 53 constituting both the first impeller 52A and the second impeller 52B can be varied as needed.

[0128] The liquefied gas delivery path 25 includes an intake section 26, an exhaust section 27, a first impeller configuration section (first configuration section) 28A, a second impeller configuration section (second configuration section) 28B, and a connecting section 72, and extends from the lower end to the upper end of the housing 22.

[0129] Inhalation section 26 and Figure 2 Similarly, in the first embodiment shown, it is disposed at the lower end of the housing 22 and connected to the lower center of the first impeller configuration portion 28A on the lower side. A rolling bearing 57 and an inducer 58 are disposed within the suction portion 26. The discharge portion 27 is connected to the outer periphery of the discharge portion 28f of the upper second impeller configuration portion 28B, and... Figure 4 Similarly, the second embodiment shown extends upwards, bypassing the cooling flow path (second cooling flow path) 68.

[0130] The first impeller configuration section 28A is provided for configuring the first impeller 52A. The first impeller configuration section 28A communicates with the upper end of the suction section 26, including the suction port 26a, and extends along the axis A. The first impeller configuration section 28A is provided with a partition wall 28a that separates the first impeller 52A from the adjacent enclosed impellers 53.

[0131] The second impeller configuration section 28B is provided for configuring the second impeller 52B. The second impeller configuration section 28B is provided at a distance from the first impeller configuration section 28A along axis A. The second impeller configuration section 28B communicates with the lower end of the discharge section 27, including the discharge port 27a, and extends along axis A. A partition wall 28a is provided in the second impeller configuration section 28B to separate the adjacent enclosed impellers 53 of the second impeller 52B.

[0132] A bearing assembly 34 is provided adjacent to the discharge port 27a, relative to the impeller configuration sections 28A and 28B. In other words, the bearing assembly 34 is provided adjacent to the motor configuration section 30 on the side opposite to the second impeller configuration section 28B. The inflow section 69 of the cooling flow path 68, which communicates with the bearing assembly 34, is connected to the downstream side (discharge section 28f) of the second impeller configuration section 28B in the direction of liquefied gas delivery. The second impeller configuration section 28B is connected to the cooling flow path 68, including the bearing assembly 34, via a balance piston 35.

[0133] The connecting portion 72 is connected to the upper end of the first impeller configuration portion 28A and the lower end of the second impeller configuration portion 28B. The connecting portion 72 extends vertically around the motor configuration portion 30.

[0134] By constructing the liquefied gas delivery path 25 in this way, the liquefied gas in the tank 12 is drawn in from the suction port 26a under the action of the rotation of the impellers 52A and 52B driven by the superconducting motor 45, and is discharged from the discharge port 27a after passing through the suction section 26, the first impeller configuration section 28A, the connecting section 72, the second impeller configuration section 28B and the discharge section 27 in sequence.

[0135] The motor mounting section 30 is disposed within the housing 22 between the first impeller mounting section 28A and the second impeller mounting section 28B, and extends along axis A. That is, the motor mounting section 30 is disposed adjacent to the second impeller mounting section 28B on its lower side, which serves as the suction port 26a. Rolling bearings 57 are respectively disposed between the motor mounting section 30 and the first impeller mounting section 28A, and between the motor mounting section 30 and the second impeller mounting section 28B. The motor mounting section 30 is spatially connected to the first impeller mounting section 28A, and the motor mounting section 30 is spatially connected to the second impeller mounting section 28B, respectively, via the rolling bearings 57.

[0136] The cooling flow path 31 is composed of an inflow section (first inflow section) 32 that is indirectly connected to the inside of the tank 12 via the suction section 26 of the liquefied gas delivery path 25 and the first impeller configuration section 28A, and an outflow section (first outflow section) 33 that is connected to the communication section 72 of the liquefied gas delivery path 25.

[0137] An inlet section 32 is disposed between the first impeller configuration section 28A and the motor configuration section 30. The inlet section 32 opens towards the discharge portion 28f of the first impeller configuration section 28A and communicates with the interior of the container 12 via the first impeller configuration section 28A and the suction portion 26 of the liquefied gas delivery path 25. Furthermore, the inlet section 32 communicates with the interior of the motor configuration section 30. Thus, the interior of the container 12 is connected to the interior of the motor configuration section 30 via the inlet section 32, the impeller configuration section 28A, and the suction portion 26. More specifically, the inlet section 32 communicates with the discharge portion 28f, which is downstream of the first impeller configuration section 28A in the direction of liquefied gas delivery. A rolling bearing 57 is disposed within the inlet section 32. The interior of the motor configuration section 30 and the interior of the first impeller configuration section 28A are spatially connected via the rolling bearing 57. Liquefied gas can be supplied to the cooling flow path 31 under the action of the discharge pressure of the first impeller 52A.

[0138] An outlet section 33 is disposed between the second impeller configuration section 28B and the motor configuration section 30 of the liquefied gas delivery path 25. The outlet section 33 opens towards the interior of the second impeller configuration section 28B and communicates with the upstream side of the direction in which the liquefied gas is delivered relative to the second impeller configuration section 28B. A rolling bearing 57 is disposed within the outlet section 33, and the motor configuration section 30 is spatially connected to the second impeller configuration section 28B via the rolling bearing 57.

[0139] In the cooling flow path 31 configured as described above, when the liquefied gas in the tank 12 is discharged through the liquefied gas discharge path 25 under the action of the rotation of the impellers 52A and 52B and the inducer 58 driven by the superconducting motor 45, the liquefied gas flows from the inlet 32 ​​into the motor mounting section 30 under the action of the discharge pressure generated by the first impeller 52A and the attraction force generated by the second impeller 52B. Therefore, the superconducting motor 45 and the pair of rolling bearings 57 can be reliably cooled. Moreover, the internal pressure of the motor mounting section 30 can be maintained at a high level. In addition, the liquefied gas, which has been heated by the cooling of the superconducting motor 45, returns from the outlet 33 to the liquefied gas discharge path 25 (second impeller mounting section 28B) and mixes with the unheated liquefied gas before being discharged. Therefore, the vaporization of the liquefied gas caused by the temperature rise can be suppressed, and the temperature rise of the liquefied gas in the tank 12 can also be suppressed.

[0140] In the pump 10 of the second to fourth embodiments configured as described above, similar to the first embodiment, the liquefied gas in the tank 12 can be pressurized and efficiently discharged from the outlet 17a. Moreover, since a superconducting motor 45 is used, the overall size can be reduced.

[0141] (Fifth implementation method)

[0142] When reference Figure 7In this respect, the pump 10 of the fifth embodiment differs from the pump 10 of the first embodiment in that the impeller 52 is mounted on the rotating shaft 74 and the rotating shaft 74 is connected to the motor shaft 49 by a coupling 75. However, the structure of mounting the rotating shaft 74 to the motor shaft 49 by a coupling 75 can also be applied to pumps 10 of other embodiments.

[0143] The main portion 49a of the motor shaft 49 of the superconducting motor 45 protrudes into the coupling configuration portion 76 formed in the housing 22 and terminates within the coupling configuration portion 76.

[0144] The rotating shaft 74 extends downward along axis A from the coupling configuration 76 of the housing 22 to the suction section 26. The upper and lower ends of the rotating shaft 74 are supported by rolling bearings 57 to enable rotation. The rotor 37 of the balancing piston 35 and the impeller 52 are respectively mounted on the rotating shaft 74 without relative movement in the circumferential and axial directions.

[0145] The coupling 75 is disposed within the coupling mounting section 76 of the housing 22, and connects the ends of the motor shaft 49 and the rotating shaft 74 in a manner that prevents them from rotating relative to each other. The coupling 75 can be any structure capable of connecting the motor shaft 49 and the rotating shaft 74. For example, a magnetic coupling, a rigid coupling, or a flexible coupling can be used in the coupling 75.

[0146] The cooling flow path 31 of the housing 22 is similar to that of the first embodiment, including an inlet portion 32, an outlet portion 33, and a bearing mounting portion 34. In addition, the cooling flow path 31 of this embodiment includes a coupling mounting portion 76 between the inlet portion 32 and the motor mounting portion 30.

[0147] The coupling mounting section 76 is a space for mounting the coupling 75 and is located between the inlet section 32 and the motor mounting section 30. Rolling bearings 57 are respectively mounted between the coupling mounting section 76 and the inlet section 32, and between the coupling mounting section 76 and the motor mounting section 30. The coupling mounting section 76 is divided relative to the inlet section 32 and the motor mounting section 30 by the rolling bearings 57. Furthermore, the coupling mounting section 76 is spatially connected relative to the inlet section 32 and the motor mounting section 30 via the rolling bearings 57. Thus, similar to the first embodiment, a portion of the liquefied gas delivered through the liquefied gas delivery path 25 can be supplied to the cooling flow path 31, including the motor mounting section 30.

[0148] (Sixth Implementation Method)

[0149] When reference Figure 8 At that time, the pump 10 of the sixth embodiment is set to replace Figure 2The structure shown, which uses a balance disc 78 as a balancing device instead of a balance piston 35, differs from the pump 10 of the first embodiment in that it does not use a magnetic bearing 55. However, the structure that uses a balance disc 78 instead of a balance piston 35 can also be applied to the pump 10 in other embodiments.

[0150] The balance disc 78 is disposed within the inflow portion 32 of the cooling flow path 31 in the housing 22. The balance disc 78 includes a fixed disc 78a and a rotating disc 78b, and is connected to... Figure 2 The balance piston 35 shown also functions as a pressure-reducing element.

[0151] The fixed disk 78a is mounted in the inlet portion 32 of the cooling flow path 31 within the housing 22. The rotating disk 78b is mounted relative to the motor shaft 49 of the superconducting motor 45 in both the circumferential and axial directions, ensuring that it cannot move relative to the motor shaft 49. A first gap extending axially along the motor shaft 49 and a second gap extending radially orthogonal to the motor shaft 49 are maintained between the fixed disk 78a and the rotating disk 78b. These gaps constitute a flow path through which liquefied gas passes. That is, the balance disk 78 connects the liquefied gas outlet path 25 and the cooling flow path 31 via the gap between the fixed disk 78a and the rotating disk 78b. Thus, similar to the first embodiment, a portion of the liquefied gas delivered through the liquefied gas outlet path 25 can be supplied to the cooling flow path 31, including the motor mounting portion 30.

[0152] In the pump unit 20 using the balance disc 78, the thrust generated by the impeller 52 can be increased under the influence of the pressure difference between the discharge pressure on the liquefied gas outlet side 25 and the back pressure on the cooling flow path 31 side. Figure 8 The middle is facing down) produces the opposite orientation (in Figure 8 The load is oriented upwards. Therefore, the axial thrust of the motor shaft 49 of the superconducting motor 45 can be balanced. That is, the thrust brought by the impeller 52 can be counteracted, so the magnetic bearing 55 supporting the axial direction is not required.

[0153] However, the configuration of the balance disc 78 is not limited to between the motor body 46 and the impeller 52, and can be changed as needed. For example, the balance disc 78 can also be configured at the front end of the sub-section 49b of the motor shaft 49, that is, downstream of the motor mounting section 30 in the cooling flow path 31. In this way, the motor mounting section 30 can be set to a high pressure equal to the pump discharge pressure. Therefore, the cooling flow path 31, including the motor mounting section 30, can be maintained at a high pressure, thus effectively suppressing the vaporization of liquefied gas. In addition, the liquefied gas heated by the heat generated by the balance disc 78 does not flow into the motor mounting section 30, thus keeping the temperature inside the motor mounting section 30 even lower. Therefore, the motor body 46 can be effectively cooled.

[0154] (Seventh Implementation)

[0155] When reference Figure 9 In this embodiment, the pump 10 differs from the pump 10 of the first embodiment in that it has balance holes 53a provided in the plurality of enclosed impellers 53 constituting the impeller 52. However, the structure of providing balance holes 53a in the enclosed impellers 53 can also be applied to pumps 10 in other embodiments. It should be noted that in this embodiment, a structure without a balance piston 35 is shown, but a balance piston 35 can also be used in the same way as in the first embodiment, and a balance disc 78 can also be used in the same way as in the sixth embodiment.

[0156] When reference Figure 10 At this time, the balance hole 53a is provided in the rear cover 53c, which constitutes the front cover 53b and the rear cover 53c of the enclosed impeller 53, and passes through the motor shaft 49. Multiple balance holes 53a are provided at intervals around the motor shaft 49. It should be noted that... Figure 10 The designation 53d indicates the blade plate. Additionally, a decompression space 80 is ensured between the rear shield 53c and the partition wall 28a.

[0157] In the pump 10 configured in this way, on the suction side of the enclosed impeller 53 (in Figure 10 The middle side is the lower side) and the ejection side (in Figure 10 Under the pressure difference (between the upper and lower sides), a portion of the liquefied gas discharged from the closed impeller 53 flows upstream in a countercurrent manner through the space between the closed impeller 53 and the partition wall 28a. In contrast, in this embodiment, a balance hole 53a is provided in the closed impeller 53, and a pressure-reducing space 80 is provided between the rear cover 53c and the partition wall 28a. Therefore, the pressure acting on the back side (rear cover 53c) of the closed impeller 53 can be reduced. Consequently, the pressure difference between the suction and discharge sides of the closed impeller 53 becomes smaller, thus reducing the axial thrust generated by the impeller 52. As a result, it is possible to eliminate the need for... Figure 2 The pump 10 is constructed using the balance piston 35 shown. Furthermore, when using the balance piston 35 or the balance disc 78, the size and shape of the balance piston 35 can be simplified.

[0158] (Eighth Implementation)

[0159] When reference Figure 11 In this respect, the pump 10 of the eighth embodiment differs from the pump 10 of the first embodiment in that the first impeller 52A and the second impeller 52B are arranged at intervals along the motor shaft 49 and the axial thrust generated by them is counteracted. However, the structure of using the first impeller 52A and the second impeller 52B to counteract the axial thrust can also be applied to the pump 10 of other embodiments.

[0160] The first impeller 52A is disposed on the suction section 26 side of the liquefied gas delivery path 25, and the second impeller 52B is disposed between the first impeller 52A and the superconducting motor 45. The first impeller 52A and the second impeller 52B are composed of multi-stage impellers having the same number of enclosed impellers 53. The suction side of the first impeller 52A is disposed on the lower side, and the discharge side is disposed on the upper side. The suction side of the second impeller 52B is disposed on the upper side, and the discharge side is disposed on the lower side. That is, the first impeller 52A and the second impeller 52B are arranged with their backs facing each other (discharge sides).

[0161] The liquefied gas delivery path 25, like in the fourth embodiment, includes an intake section 26, an exhaust section 27, a first impeller configuration section (first configuration section) 28A, a second impeller configuration section (second configuration section) 28B, and a connecting section 72, and extends from the lower end to the upper end of the housing 22.

[0162] The suction section 26 is located at the lower end of the housing 22 and is connected to the lower center of the first impeller configuration section 28A on the lower side. A rolling bearing 57 and an inducer 58 are disposed inside the suction section 26. The discharge section 27 is connected to the discharge portion 28f of the lower outer periphery of the second impeller configuration section 28B on the upper side, and extends upward around the second impeller configuration section 28B and the cooling flow path 31.

[0163] The first impeller configuration section 28A is provided for configuring the first impeller 52A. The first impeller configuration section 28A communicates with the upper end of the suction section 26, including the suction port 26a, and extends along the axis A. The first impeller configuration section 28A is provided with a partition wall 28a that separates the adjacent enclosed impellers 53 of the impeller 52A.

[0164] The second impeller configuration section 28B is provided for configuring the second impeller 52B. The second impeller configuration section 28B is provided at a distance from the first impeller configuration section 28A along axis A. The second impeller configuration section 28B communicates with the lower end of the discharge section 27, including the discharge port 27a, and extends along axis A. A partition wall 28a is provided in the second impeller configuration section 28B to separate adjacent enclosed impellers 53 of the impeller 52B.

[0165] The connecting portion 72 is connected to the upper end (discharge portion 28f) of the first impeller configuration portion 28A and the upper end (suction portion) of the second impeller configuration portion 28B. The connecting portion 72 extends vertically around the second impeller configuration portion 28B.

[0166] The cooling flow path 31, which communicates with the motor mounting section 30, is connected to the upper end of the connecting section 72, i.e., the liquefied gas delivery path 25, at a position downstream of the first impeller mounting section 28A and upstream of the second impeller mounting section 28B. No inlet section 32 of the cooling flow path 31 is configured with… Figure 2 The balance piston 35 shown and Figure 8 The balance disc 78 is located in the middle. Under the action of the discharge pressure of the first impeller 52A, a portion of the liquefied gas discharged through the liquefied gas discharge path 25 can flow into the cooling flow path 31.

[0167] In the pump 10 configured in this way, the axial thrust generated by the first impeller 52A is... Figure 11 The downward action, the shaft thrust brought by the second impeller 52B, in the middle Figure 11 The upward-facing action is achieved. Furthermore, both the first impeller 52A and the second impeller 52B consist of the same number of multi-stage impellers, thus generating roughly the same axial thrust. As a result, the axial thrust acting on the motor shaft 49 can be counteracted, thus eliminating the need for... Figure 2 The balance piston 35 shown and Figure 8 The balance disc 78 in the middle constitutes the pump 10.

[0168] (Ninth Implementation)

[0169] When reference Figure 12 In the ninth embodiment, the pump 10 separates the liquefied gas intake section 26A (held by the first impeller 52A) and the liquefied gas intake section 26B (held by the second impeller 52B) in the liquefied gas delivery path 25, and removes... Figure 11 The connection portion 72 shown differs from that of the pump 10 in the eighth embodiment. However, the structure using a pair of impellers 52A and 52B and corresponding suction portions 26A and 26B can also be applied to the pump 10 in other embodiments.

[0170] The liquefied gas delivery path 25 includes a pair of intake sections 26A and 26B, an exhaust section 27, and a pair of impeller configuration sections 28A and 28B.

[0171] The first suction section 26A is located at the lower end of the housing 22 and is connected to the lower center of the first impeller mounting section 28A on the lower side. A rolling bearing 57 and an inducer 58 are disposed inside the first suction section 26A.

[0172] The second suction section 26B is disposed on the upper side of the housing 22 between the second impeller configuration section 28B and the cooling flow path 31, and extends radially orthogonal to axis A. The second suction section 26B is connected to the upper central portion of the second impeller configuration section 28B and is also connected to the cooling flow path 31. An inducer 58 is disposed within the second suction section 26B.

[0173] The discharge section 27 is connected to the discharge sections 28f of each of the pair of impeller configuration sections 28A and 28B. Specifically, the upper end of the discharge side of the first impeller configuration section 28A and the lower end of the discharge side of the second impeller configuration section 28B are connected to the common discharge section 28f. The discharge section 27 is connected to the outer periphery of the discharge section 28f and extends upward around the second impeller configuration section 28B and the cooling flow path 31.

[0174] The cooling flow path 31, which communicates with the motor mounting section 30, is connected to the upper second suction section 26B. No inflow section 32 of the cooling flow path 31 is provided. Figure 2 The balance piston 35 shown and Figure 8 The balance disc 78 is located in the middle. A portion of the liquefied gas drawn in through the second suction section 26B can flow into the cooling flow path 31. However, in order to ensure the amount of liquefied gas flowing into the cooling flow path 31, an axial flow impeller may also be provided in the inlet section 32 or the motor mounting section 30.

[0175] exist Figure 11 The eighth embodiment shown is the same as Figure 12 In the pump 10 of the ninth embodiment shown, the first impeller 52A and the second impeller 52B may also be configured such that their front faces (suction sides) are facing each other.

[0176] (Tenth Implementation)

[0177] When reference Figure 13 In this respect, the pump 10 of the tenth embodiment differs from the pump 10 of the first embodiment in that the closed impeller 53 located at the lower end of the suction side end (primary) of the impeller 52 is configured as a double-suction type capable of drawing liquefied gas from both sides axially. However, the structure of configuring the closed impeller 53 at the suction side end as a double-suction type can also be applied to pumps 10 of other embodiments.

[0178] The impeller 52 consists of multiple enclosed impellers 53A (second stage and above from bottom to top) and a single enclosed impeller 53B (primary stage only). The enclosed impeller 53A is a single-suction type with the suction side located on the lower side. The enclosed impeller 53B is a double-suction type with suction sides on both the upper and lower sides.

[0179] The suction section 26 of the liquefied gas delivery path 25 extends radially inward from the suction port 26a located on the outer peripheral surface of the housing 22 and communicates with the lower outer peripheral portion of the impeller configuration section 28, which is equipped with a closed impeller 53B.

[0180] The impeller configuration section 28 has multiple partition walls 28a arranged in an annular shape to separate multiple enclosed impellers 53A. Furthermore, a partition wall 28b with a different shape than the other partition walls 28a is provided between the primary enclosed impeller 53B and the second-stage enclosed impeller 53A in the impeller configuration section 28. The partition wall 28b defines an involute passage that connects the portion where the primary enclosed impeller 53B is located with the portion where the second-stage enclosed impeller 53A is located.

[0181] In this configuration of pump 10, the primary enclosed impeller 53B is designed as a double-suction type, thus allowing the flow rate of each blade to be halved. As a result, the required suction head of impeller 52 can be reduced.

[0182] (Eleventh Implementation Method)

[0183] When reference Figure 14 In this respect, the pump 10 of the eleventh embodiment differs from the pump 10 of the first embodiment in that it modifies the suction section 26 of the liquefied gas delivery path 25 and sets it to a series-connected impeller 52 capable of drawing in liquefied gas using two enclosed impellers 53. However, the structure of setting the impellers 52 in series can also be applied to pumps 10 in other embodiments.

[0184] Impeller 52 is a single-suction type with the suction side located on the lower side and is composed of multiple enclosed impellers 53.

[0185] The suction section 26 of the liquefied gas delivery path 25 extends radially inward from the suction port 26a located on the outer peripheral surface of the housing 22 and communicates with the lower outer peripheral portion of the impeller configuration section 28, which is equipped with a closed impeller 53 located at the lower end.

[0186] The impeller configuration section 28 is provided with multiple partition walls 28a in an annular shape, separating multiple enclosed impellers 53 from the bottom up (second stage and above). Furthermore, a partition wall 28c of a different shape than the other partition walls 28a is provided between the lower enclosed impeller 53 and the second-stage enclosed impeller 53 in the impeller configuration section 28. Additionally, a flow divider wall 28d is provided in the section where the lower enclosed impeller 53 is configured, facing the suction inlet 26a. The flow divider wall 28d divides the liquefied gas drawn in from the suction section 26 into the lower enclosed impeller 53 side and the second-stage enclosed impeller 53 side. Furthermore, the section where the lower enclosed impeller 53 is configured and the section where the second-stage enclosed impeller 53 is configured are connected via a connecting section 28e.

[0187] In this pump 10 configuration, the impellers 52 are arranged in series, capable of drawing in liquefied gas using two enclosed impellers 53. Therefore, similar to the tenth embodiment, the flow rate through each blade can be halved. As a result, the necessary suction head of the impeller 52 can be reduced.

[0188] (Twelfth Implementation)

[0189] When reference Figure 15 In this respect, the pump 10 of the twelfth embodiment differs from the pump 10 of the first embodiment in that the axis of the motor shaft 49, including the axis A of the barrel 12, is arranged to extend horizontally. Regarding the structure of the pump unit 20, it is the same as in the first embodiment. That is, the pump unit 20 is composed of a horizontal-axis multi-stage diffusion pump. However, the structure of the pump unit 20 as a horizontal-axis multi-stage diffusion pump can also be applied to pumps 10 in other embodiments.

[0190] The barrel 12 has a cylindrical outer peripheral wall 13, a first sealing wall 14 that closes one end of the outer peripheral wall 13, and a second sealing wall 15 that closes the other end of the outer peripheral wall 13. A cylindrical intake portion 16 protruding radially outward is provided on the outer peripheral wall 13. A cylindrical discharge portion 17 protruding outward along axis A is provided on the second sealing wall 15. The outer end opening of the intake portion 16 forms an intake port 16a, and the outer end opening of the discharge portion 17 forms a discharge port 17a.

[0191] A support portion 85 is provided between the outer peripheral wall 13 and the housing 22 of the motor unit 20. The support portion 85 supports the lower side of the housing 22, which is joined by a cantilever structure. In this embodiment, support portions 85 are provided at both ends of the housing 22. However, the number of support portions 85 can be one or more, as long as the structure can support the motor unit 20 in a stable state, and can be changed as needed.

[0192] (Thirteenth Implementation Method)

[0193] When reference Figure 16 In the same way as the pump 10 of the twelfth embodiment, the pump 10 of the thirteenth embodiment includes a pump unit 20 in which the axis of the motor shaft 49, including the axis A of the barrel 12, extends horizontally. This pump 10 differs from the pump 10 of the twelfth embodiment in that it uses the housing 22 of the pump unit 20 to liquid-tightly seal one end of the outer peripheral wall 13 of the barrel 12. However, this structure of liquid-tightly sealing one end of the outer peripheral wall 13 of the barrel 12 using the housing 22 can also be applied to pumps 10 in other embodiments.

[0194] The barrel 12 has a cylindrical outer peripheral wall 13 and a first sealing wall 14 that closes one end of the outer peripheral wall 13. The barrel 12 does not have... Figure 15 The second sealing wall 15 is shown. On the outer peripheral wall 13, an inwardly protruding annular flange portion 13a is provided at the end opposite to the first sealing wall 14. The flange portion 13a can abut against the outer peripheral surface of the housing 22 and also functions as a support portion for supporting the pump unit 20.

[0195] The pump unit 20 differs from the twelfth embodiment in that it has a flange 22a only at the end of the housing 22 where the discharge port 27a is located. The flange 22a protrudes radially outward from the end of the housing 22 and is fluid-tightly engaged with the flange 13a of the barrel 12.

[0196] A support portion 85 is provided between the outer peripheral wall 13 of the barrel 12 and the housing 22 of the motor unit 20. The support portion 85 is composed of an annular plate and supports the end of the housing 22 on the side of the suction port 26a. Multiple liquid passage holes are provided in the support portion 85 within a range sufficient to ensure the strength required to support the pump unit 20. This allows the barrel 12 to be filled with liquefied gas. However, the support portion 85 can be modified as needed, as long as it is a structure capable of supporting the housing 22; for example, it can be composed of a cylindrical retaining portion surrounding the housing 22 and multiple ribs projecting radially from the retaining portion.

[0197] In the pump 10 of the twelfth and thirteenth embodiments configured as described above, the same function and effect as in the first embodiment can be obtained.

[0198] (Fourteenth Implementation)

[0199] When reference Figure 17 In this respect, the pump 10 of the fourteenth embodiment differs from the first embodiment in that it returns the liquefied gas from the cooling flow path 31 to the impeller configuration section 28 without allowing the liquefied gas to flow out of the cooling flow path 31 into the tank 12. However, the structure that returns the liquefied gas from the cooling flow path 31 to the impeller configuration section 28 can also be applied to other embodiments.

[0200] Specifically, in the fourteenth embodiment, the pump 10 is arranged from the bottom to the top along axis A in the order of impeller 52, superconducting motor 45 and magnetic bearing 55.

[0201] The cooling flow path 31 consists of an inlet section 32, an outlet section 33, and a bearing mounting section 34. The inlet section 32 communicates with the discharge section 28f of the impeller mounting section 28 and indirectly connects the motor mounting section 30 to the inside of the tank 12 via the liquefied gas delivery path 25. The outlet section 33 communicates with the bearing mounting section 34 and opens towards the inside of the tank 12, indirectly connecting the motor mounting section 30 to the inside of the tank 12 via the bearing mounting section 34.

[0202] A return pipe 87, serving as an example of a return path, is connected to the outlet of the outflow section 33, where the throttling orifice 39 is installed. The return pipe 87 extends downward within the barrel 12 and connects to the lower part of the impeller configuration section 28, more specifically, to the radially outer portion of the lowest closed impeller 53 in the impeller 52. This piping of the return pipe 87 connects the motor configuration section 30 to the impeller configuration section 28, thus increasing the pressure at the outlet of the cooling flow path 31, where the throttling orifice 39 is located, compared to the case where liquefied gas returns from the throttling orifice 39 into the barrel 12. Consequently, the pressure within the motor configuration section 30 can be maintained at a higher level.

[0203] However, the return pipe 87 can also be connected to any part of the impeller configuration section 28 other than the lowermost enclosed impeller 53. Furthermore, the enclosed impeller 53 located at the connection point of the return pipe 87 is preferably configured to adjust the pressure within the cooling flow path 31, including the motor configuration section 30, to an appropriate value by adjusting its diameter. Additionally, the return path is not limited to a structure using a return pipe 87 separate from the housing 22; it can also be a structure provided within the housing 22, such as the discharge section 27 of the liquefied gas delivery path 25.

[0204] Similar to the first embodiment, this pump 10 can efficiently deliver liquefied gas while suppressing overall enlargement. Furthermore, the pressure at the outlet of the cooling flow path 31, where the throttling orifice 39 is provided, increases, thus effectively suppressing the vaporization of liquefied gas within the cooling flow path 31.

[0205] (Fifteenth Implementation)

[0206] When reference Figure 18 In the fifteenth embodiment, the pump 10 differs from the third embodiment in that it is provided with a supply pipe (supply path) 88 for supplying liquefied gas from the impeller assembly 28 to the motor assembly 30, and a return pipe (return path) 87 for returning liquefied gas from the motor assembly 30 to the impeller assembly 28. However, the structure of providing the supply pipe 88 and the return pipe 87 can also be applied to other embodiments.

[0207] Specifically, in the fifteenth embodiment, the pump 10 is arranged from bottom to top along axis A in the order of superconducting motor 45, impeller 52, and magnetic bearing 55. The impeller mounting section 28, which houses the impeller 52, is divided by multiple partition walls 28a into a closed impeller 53 constituting the impeller 52. Furthermore, the motor mounting section 30, which houses the motor body 46 containing the superconducting motor 45, has an inlet section (first inlet section) 32 with its outer end opening towards the inside of the tank 12 and its inner end opening towards the inside of the motor mounting section 30, and an outlet section (first outlet section) 33. The outlet section 33 is provided with… Figure 3 The throttling orifice 39 is shown.

[0208] As an example of a liquid supply path, the liquid supply pipe 88 is connected to the portion of the impeller configuration section 28 where the closed impeller 53, which is the second stage from the bottom, is located. The liquid supply pipe 88 extends downward inside the tank 12 and is connected to the inlet section 32 of the motor configuration section 30. However, the liquid supply pipe 88 can be connected to the portion of the impeller configuration section 28 where the lower closed impeller 53 is located, only externally. In addition, the liquid supply path is not limited to a structure using a liquid supply pipe 88 that is separate from the housing 22; it can also be a structure provided within the housing 22, such as the discharge section 27 of the liquefied gas delivery path 25.

[0209] As an example of a return path, the return pipe 87 is connected to the outlet portion 33 of the motor mounting section 30. The return pipe 87 extends upward inside the barrel 12 and is connected to the portion of the impeller mounting section 28 where the lower end of the closed impeller 53 is located. However, the return pipe 87 can be connected to the impeller mounting section 28 at a position lower (suction side) than the connection portion of the liquid supply pipe 88. In addition, the return path is not limited to a structure using a return pipe 87 that is separate from the housing 22; it can also be a structure provided in the housing 22, such as the discharge portion 27 of the liquefied gas delivery path 25.

[0210] In this pump 10 configuration, a portion of the liquefied gas is supplied from the impeller assembly 28 to the motor assembly 30 via the supply pipe 88, driven by the rotation of the impeller 52 caused by the superconducting motor 45. Furthermore, the liquefied gas, having cooled the motor body 46, returns from the motor assembly 30 to the impeller assembly 28 via the return pipe 87. Because the supply pipe 88 is connected to the return pipe 87 near the discharge side in the impeller assembly 28, the flow of the liquefied gas is reliably maintained under the pressure difference at the connection point.

[0211] Similar to the first embodiment, this pump 10 can efficiently deliver liquefied gas while suppressing overall enlargement. Furthermore, under the action of the liquid supply pipe 88, a portion of the delivered liquefied gas is forcibly supplied to the motor mounting section 30, which is provided with a throttling orifice 39 in the outlet section 33, thereby increasing the pressure within the motor mounting section 30 and effectively suppressing the vaporization of the liquefied gas.

[0212] Furthermore, the liquefied gas in the motor mounting section 30 does not flow out to the low-pressure tank 12 but returns to the impeller mounting section 28, thus suppressing BOG (Break-off Gas). However, if there is no concern about BOG, the return pipe 87 can be omitted, allowing the liquefied gas in the motor mounting section 30 to flow into the tank 12. Alternatively, without using the return pipe 87, the supply pipe 88 can be connected to the portion of the impeller mounting section 28 where the lower closed impeller 53 is located.

[0213] (Sixteenth Implementation)

[0214] When reference Figure 19 In this respect, the pump 10 of the sixteenth embodiment differs from the first embodiment in that the throttling orifice 39, which is an example of a pressure reducing device, is disposed outside the tank 12. However, the structure of disposing the pressure reducing device outside the tank 12 can also be applied to other embodiments.

[0215] A connecting pipe (connecting flow path) 90A is connected to the outlet 33 of the cooling flow path 31, which penetrates the top wall 15 and leads to the outside of the barrel 12. The front end of the connecting pipe 90A is connected to the sealed container 91. The sealed container 91 includes a container body 92 and a cover 93.

[0216] The container body 92 is an open-top container and is liquid-tightly mounted to the top wall 15. A through hole 92a is provided in the container body 92, through which a bolt 40 is threaded to form a throttling orifice 39. The through hole 92a communicates with the interior of the barrel 12 via the through hole formed in the top wall 15. However, the container body 92 can also be mounted on the outer peripheral wall 13 of the barrel 12. Alternatively, the container body 92 can also be a structure in which the through hole 92a is connected to the through hole of the barrel 12 using a connecting pipe.

[0217] The cover 93 is detachably installed on the upper end of the container body 92 and liquid-tightly seals the opening of the container body 92. The cover 93 is connected to a connecting pipe 90A and has a connecting hole 93a that communicates with the inside of the container body 92.

[0218] In this pump 10, the throttling orifice 39 is located on the outside of the tank 12, so the throttling orifice 39 can be replaced without disassembling the pump 10 during maintenance. Therefore, the maintainability of the pump 10 can be improved. However, alternatively, the connecting pipe 90A could be replaced, such as... Figure 19 As shown by the dashed line, the outlet 33 of the cooling flow path 31 is connected to the throttling orifice 39 outside the barrel 12 via a connecting flow path 90B, which is formed by a first connecting path 90a provided in the housing 22 and a second connecting path 90b provided in the container body 92. The first connecting path 90a and the second connecting path 90b are connected via a through hole formed in the top wall 15. In this case, the outlet of the outlet 33 is blocked, and the outlet 33 is connected to the inside of the barrel 12 via the connecting flow path 90B and the through hole 92a of the container body 92. This prevents the piping (connecting pipe 90A) from being led out of the barrel 12. In addition, even when using the connecting pipe 90A, if the front end of the connecting pipe 90A is connected to the second connecting path 90b of the container body 92, it is possible to prevent the connecting pipe 90A from being led out of the barrel 12. Thus, the structure for connecting the outlet 33 of the cooling flow path 31 to the throttling orifice 39 outside the barrel 12 can be changed as needed.

[0219] (Seventeenth Implementation)

[0220] When reference Figure 20 In the seventeenth embodiment, the pump 10 differs from the first embodiment in that the motor shaft 49 protrudes from the suction port 26a into the barrel 12 and the front end of the motor shaft 49 is supported by the support portion 95 so that it can rotate. However, the structure of supporting the front end of the motor shaft 49 by the support portion 95 can also be applied to other embodiments.

[0221] A bell-shaped mouth portion 22b is formed at the lower end of the housing 22, extending outwards towards the lower end. The lower opening of the bell-shaped mouth portion 22b constitutes an intake port 26a. The support portion 95 is a container-shaped structure with an open upper end and is connected to the inner circumferential surface of the bell-shaped mouth portion 22b via a plurality of radially extending guide wings 96. A rolling bearing 57 is disposed within the support portion 95 to bear the radial load of the motor shaft 49. Furthermore, a radially penetrating through hole 95a is formed in the support portion 95, located below the rolling bearing 57.

[0222] In this pump 10, the rolling bearing 57, which bears the radial load, is disposed between the motor mounting section 30 and the bearing mounting section 34, in addition to the support section 95. That is, the motor shaft 49 is supported by a magnetic bearing (axial bearing) 55, a bottom bearing 56, and two rolling bearings 57 to enable it to rotate.

[0223] In this pump 10, when the number of enclosed impellers 53 constituting the impeller 52 is small, the length (shaft span) between adjacent support portions in the motor shaft 49 is also shorter. Therefore, when the natural frequency of all rotating bodies, including the impeller 52 and the rotor 48, is higher than the operating frequency, it can operate in a stable state.

[0224] (Eighteenth Implementation)

[0225] When reference Figure 21 In this respect, the pump 10 of the eighteenth embodiment differs from the first embodiment in that a rolling bearing 57 for bearing the radial load of the motor shaft 49 is provided between one of the plurality of enclosed impellers 53 constituting the impeller 52. However, the structure of providing a rolling bearing 57 between the plurality of enclosed impellers 53 can also be applied to other embodiments.

[0226] Specifically, the pump 10 is arranged along axis A from bottom to top in the order of impeller 52, superconducting motor 45, and magnetic bearing 55. Among them, the impeller mounting section 28 that mounts the impeller 52 is divided into a closed impeller 53 constituting the impeller 52 by multiple partition walls 28a.

[0227] A rolling bearing 57 is installed in the impeller configuration section 28, which separates the lower closed impeller 53 from the second-stage closed impeller 53. In other words, a partition wall 28a is provided in the space between adjacent closed impellers 53, and a rolling bearing 57 is arranged in the space between the lower closed impeller 53 and the second-stage closed impeller 53. A communication hole 28g for ensuring the flow rate of liquefied gas is provided in the partition wall 28a where the rolling bearing 57 is installed. However, the rolling bearing 57 can be arranged in any space other than between the lower closed impeller 53 and the second-stage closed impeller 53, as long as it is in the space between adjacent closed impellers 53. In addition, the rolling bearing 57 can be arranged in two or more of the multiple spaces formed by multiple closed impellers 53.

[0228] In this type of pump 10, when there are many enclosed impellers 53 constituting the impeller 52, the distance between the parts supported by bearings in the motor shaft 49 (shaft span) becomes longer, thus lowering the natural frequency of all rotating parts, including the impellers 52 and the rotor 48. In contrast, in the pump 10 of this embodiment, a rolling bearing 57 is arranged in one of the spaces between the multiple enclosed impellers 53, shortening the distance between the parts supported by the rolling bearing 57 in the motor shaft 49. Therefore, the natural frequency of the rotating parts can be higher than the operating frequency, enabling the pump 10 to operate in a stable state.

[0229] (Nineteenth implementation method)

[0230] When reference Figure 22 In this respect, the pump 10 of the nineteenth embodiment differs from the third embodiment in that the superconducting motor 45 is positioned above the impeller 52 and the magnetic bearing 55 is positioned below it. However, the structure in which the superconducting motor 45 and the magnetic bearing 55 are arranged in opposite directions can also be applied to the pump 10 of the second, fourth, and fifteenth embodiments.

[0231] Specifically, the pump 10 is arranged along axis A from bottom to top in the order of magnetic bearing 55, impeller 52 and superconducting motor 45.

[0232] The liquefied gas delivery path 25 includes an intake section 26, an exhaust section 27, and an impeller mounting section 28. The intake section 26 extends radially in the middle portion of the housing 22 in the vertical direction. The impeller mounting section 28 communicates with the intake section 26 and extends downward along axis A. The exhaust section 27 communicates with the exhaust portion 28f located at the lowermost side of the impeller mounting section 28 and extends to the upper end of the housing 22, bypassing the impeller mounting section 28 and the motor mounting section 30.

[0233] The motor mounting section 30 is located on the upper side of the impeller mounting section 28. The motor mounting section 30 is connected to the inside of the tank 12 via a cooling flow path 31 having an inflow section (first inflow section) 32 and an outflow section (first outflow section) 33 consisting of multiple through holes.

[0234] The bearing mounting section 34 is disposed on the lower side opposite to the impeller mounting section 28 and located on the opposite side of the motor mounting section 30. The bearing mounting section 34 is connected to the inside of the tank 12 by a cooling flow path 68 having an inflow section (second inflow section) 69 that communicates with the discharge section 28f of the impeller mounting section 28 and an outflow section (second outflow section) 70 that communicates directly with the inside of the tank 12.

[0235] In this pump 10, similar to the first embodiment, it is possible to efficiently deliver liquefied gas while suppressing overall enlargement, and achieve the same function and effect as the embodiment described above.

[0236] It should be noted that the present invention is not limited to the structure of the described embodiments and various modifications can be made.

[0237] For example, the support for the motor shaft 49 of the superconducting motor 45 is not limited to a combination of magnetic bearing 55 and rolling bearing 57; it can also be composed entirely of any one of magnetic bearings, rolling bearings, and sliding bearings. Alternatively, it can be a combination of magnetic bearings and sliding bearings, or a combination of rolling bearings and sliding bearings, and the combination of the types of bearings 55 and 57 can be changed as needed.

[0238] about Figure 4 The second embodiment shown Figure 5 The third embodiment shown and Figure 22 In the nineteenth embodiment shown, the superconducting motor 45 may also be a structure in which the motor shaft 49 protrudes from the motor body 46 in only one direction (main part 49a).

[0239] Pump unit 20 is not limited to a multi-stage diffusion pump. It can be any of the following types of pumps housed within the container 12: turbine centrifugal pump, single-suction vortex pump, double-suction vortex pump, mixed-flow pump, vortex-mixed-flow pump, mixed-flow pump, and axial-flow pump. It can also be a special type of vortex pump or cascade pump. In other words, the type of pump unit 20 can be changed as needed. Of course, the motor shaft 49 of the superconducting motor 45 can be a vertical shaft as in the first to eleventh embodiments and the fourteenth to nineteenth embodiments, or a horizontal shaft as in the twelfth and thirteenth embodiments.

[0240] The impeller 52 used in pump unit 20 is not limited to a multi-stage impeller, and can also be composed of a single-stage impeller (i.e., a closed impeller 53). Alternatively, a semi-open impeller or an open impeller can be used instead of a closed impeller 53, and axial flow impellers or mixed flow impellers can also be used. The type of impeller 52 can be changed as needed.

[0241] Explanation of reference numerals in the attached figures

[0242] 1. Hydrogen receiving equipment

[0243] 2 storage tanks

[0244] 3. Vaporizer

[0245] 4. Gas turbine

[0246] 10 Liquefied Gas Booster Pump

[0247] 12 barrels (storage tanks)

[0248] 13. Peripheral wall

[0249] 13a Flange portion

[0250] 14. Bottom wall (first closed wall)

[0251] 15. Top wall (second enclosed wall)

[0252] 16 Intake Department

[0253] 16a Entry point

[0254] 17 Delivery Department

[0255] 17a Export

[0256] 20 pump units

[0257] 22. Shell

[0258] 22a Flange portion

[0259] 22b Bell-shaped mouth

[0260] 25 Liquefied gas delivery route

[0261] 26. Inhalation section

[0262] 26a Inlet

[0263] 26b Connecting hole

[0264] 27. Spouting section

[0265] 27a Exhalation

[0266] 28 Impeller Configuration Department

[0267] 28A First Impeller Configuration Department (First Configuration Department)

[0268] 28B Second Impeller Configuration Section (Second Configuration Section)

[0269] 28a~28c partition wall

[0270] 28d split wall

[0271] 28e Connecting part

[0272] 28f Discharge portion

[0273] 28g connecting hole

[0274] 30 Motor Configuration Department

[0275] 31 Cooling flow path (first cooling flow path)

[0276] 32. Inflow Section (First Inflow Section)

[0277] 32a Enlarged section

[0278] 33 Outflow Section (First Outflow Section)

[0279] 33a Part 1

[0280] 33b Part Two

[0281] 34 Bearing Configuration Section

[0282] 34a recess

[0283] 35. Balance piston (balancing device)

[0284] 36 Fixture

[0285] 37 Rotors

[0286] 39. Throttling orifice (pressure reducing device)

[0287] 40 bolts

[0288] 45 Superconducting Motor

[0289] 46 Motor body

[0290] 47 Stator

[0291] 48 rotors

[0292] 49 Motor Shaft

[0293] 49a main part

[0294] 49b Deputy Department

[0295] 52 Impeller

[0296] 52A First Impeller

[0297] 52B Second Impeller

[0298] 53. Enclosed impeller

[0299] 53A Single-suction type closed impeller

[0300] 53B Double-suction type closed impeller

[0301] 53a Balance hole

[0302] 53b Front Shield

[0303] 53c rear shield

[0304] 53d blade plate

[0305] 55 Magnetic bearing (axial bearing)

[0306] 56 Bottom-contact bearing

[0307] 57, 57A~57C Rolling Bearings (Radial Bearings)

[0308] 58. Induced wheel

[0309] 60 Control Department

[0310] 61 Distance sensor

[0311] 65 Axial Flow Impeller

[0312] 66 Axial Flow Impeller Configuration Section

[0313] 68 Cooling flow path (second cooling flow path)

[0314] 69. Inflow Section (Second Inflow Section)

[0315] 70 Outflow part (second outflow part)

[0316] 72 Connecting parts

[0317] 74 Rotation axis

[0318] 75 Coupling

[0319] 76 Coupling Configuration Section

[0320] 78. Balancing disc (balancing device)

[0321] 78a Fixed plate

[0322] 78b Rotary Disk

[0323] 80 Decompression Space Section

[0324] 85 Support section

[0325] 87 Return pipe (return path)

[0326] 88 Liquid supply pipe (liquid supply line)

[0327] 90A connecting pipe

[0328] 90B Connection Flow Path

[0329] 90a First Connecting Path

[0330] 90b Second Connector

[0331] 91. Sealed container

[0332] 92 Container body

[0333] 92a Through Hole

[0334] 93 masks

[0335] 93a Connecting hole

[0336] 95 Support section

[0337] 95a Through Hole

[0338] 96 Guide Wing

[0339] A. Axis (the axial direction of the motor shaft).

Claims

1. A liquefied gas booster pump, wherein, The liquefied gas booster pump includes: A storage tank having an inlet and an outlet, and storing liquefied gas taken in from the inlet; The housing is disposed within the storage tank and has a liquefied gas delivery path, the liquefied gas delivery path including an intake port that opens toward the storage tank, an outlet port that communicates with the delivery outlet port, and an impeller configuration portion formed between the intake port and the outlet port. An impeller, disposed within the impeller configuration section, is used to draw in the liquefied gas in the storage tank through the liquefied gas delivery path from the inlet and deliver it from the outlet under the action of rotation; as well as A superconducting motor having a motor body disposed within the housing and a motor shaft protruding from the motor body toward the impeller configuration and used to rotate the impeller. The shell has the following: A motor mounting section, which is axially adjacent to the impeller mounting section on the motor shaft and is a space for mounting the motor body; and A cooling flow path is provided to spatially connect the storage tank with the motor mounting section, and to cool the superconducting motor using the liquefied gas. The suction inlet of the liquefied gas delivery path is located between the impeller assembly and the motor assembly. The cooling flow path has: a first inlet portion that communicates with the motor configuration portion and opens toward the storage tank; and a first outlet portion that connects the motor configuration portion to a position in the liquefied gas delivery path upstream of the impeller configuration portion.

2. A liquefied gas booster pump, wherein, The liquefied gas booster pump includes: A storage tank having an inlet and an outlet, and storing liquefied gas taken in from the inlet; The housing is disposed within the storage tank and has a liquefied gas delivery path, the liquefied gas delivery path including an intake port that opens toward the storage tank, an outlet port that communicates with the delivery outlet port, and an impeller configuration portion formed between the intake port and the outlet port. An impeller, disposed within the impeller configuration section, is used to draw in the liquefied gas in the storage tank through the liquefied gas delivery path from the inlet and deliver it from the outlet under the action of rotation; as well as A superconducting motor having a motor body disposed within the housing and a motor shaft protruding from the motor body toward the impeller configuration and used to rotate the impeller. The shell has the following: A motor mounting section, which is axially adjacent to the impeller mounting section on the motor shaft and is a space for mounting the motor body; and A cooling flow path is provided to spatially connect the storage tank with the motor mounting section, and to cool the superconducting motor using the liquefied gas. The suction inlet of the liquefied gas delivery path is located between the impeller assembly and the motor assembly. The cooling flow path has: a first inflow portion that connects the motor configuration portion to a position upstream of the impeller configuration portion in the liquefied gas delivery path; and a first outflow portion that connects to the motor configuration portion and opens toward the storage tank.

3. A liquefied gas booster pump, wherein, The liquefied gas booster pump includes: A storage tank having an inlet and an outlet, and storing liquefied gas taken in from the inlet; The housing is disposed within the storage tank and has a liquefied gas delivery path, the liquefied gas delivery path including an intake port that opens toward the storage tank, an outlet port that communicates with the delivery outlet port, and an impeller configuration portion formed between the intake port and the outlet port. An impeller, disposed within the impeller configuration section, is used to draw in the liquefied gas in the storage tank through the liquefied gas delivery path from the inlet and deliver it from the outlet under the action of rotation; as well as A superconducting motor having a motor body disposed within the housing and a motor shaft protruding from the motor body toward the impeller configuration and used to rotate the impeller. The shell has the following: A motor mounting section, which is axially adjacent to the impeller mounting section on the motor shaft and is a space for mounting the motor body; and A cooling flow path is provided to spatially connect the storage tank with the motor mounting section, and to cool the superconducting motor using the liquefied gas. The suction inlet of the liquefied gas delivery path is located between the impeller assembly and the motor assembly. The cooling flow path has a first inlet and a first outlet that communicate with the motor configuration and open in a manner facing into the storage tank.

4. A liquefied gas booster pump, wherein, The liquefied gas booster pump includes: A storage tank having an inlet and an outlet, and storing liquefied gas taken in from the inlet; The housing is disposed within the storage tank and has a liquefied gas delivery path, the liquefied gas delivery path including an intake port that opens toward the storage tank, an outlet port that communicates with the delivery outlet port, and an impeller configuration portion formed between the intake port and the outlet port. An impeller, disposed within the impeller configuration section, is used to draw in the liquefied gas in the storage tank through the liquefied gas delivery path from the inlet and deliver it from the outlet under the action of rotation; as well as A superconducting motor having a motor body disposed within the housing and a motor shaft protruding from the motor body toward the impeller configuration and used to rotate the impeller. The shell has the following: A motor mounting section, which is axially adjacent to the impeller mounting section on the motor shaft and is a space for mounting the motor body; and A cooling flow path is provided to spatially connect the storage tank with the motor mounting section, and to cool the superconducting motor using the liquefied gas. The motor shaft protrudes in both directions from the motor body. The impeller configuration includes a first configuration and a second configuration, which are spaced apart axially from each other on the motor shaft. The impeller includes a first impeller disposed in the first configuration section and a second impeller disposed in the second configuration section. The motor configuration unit is disposed between the first configuration unit and the second configuration unit. The cooling flow path includes: a first inlet section communicating with the first configuration section and allowing the motor configuration section to communicate with the storage tank via the liquefied gas outlet section; and a first outlet section communicating with both the motor configuration section and the second configuration section. The shell has the following: A bearing configuration section is a space located on the opposite side of the motor configuration section relative to the second configuration section, and is used to configure a bearing; The second inlet section connects the liquefied gas outlet section to the bearing mounting section; and The second outlet connects the bearing configuration section to the storage tank.

5. The liquefied gas booster pump according to any one of claims 1 to 3, wherein, The shell has the following: The bearing configuration section is a space located on the opposite side of the motor configuration section relative to the impeller configuration section, and is used to configure the bearing; The second inlet section connects the liquefied gas outlet section to the bearing mounting section; and The second outlet connects the bearing configuration section to the storage tank.

6. The liquefied gas booster pump according to claim 4, wherein, A pressure reducing device is connected to the second outlet section to ensure that the bearing configuration section has a higher pressure than the storage tank.

7. The liquefied gas booster pump according to claim 5, wherein, A pressure reducing device is connected to the second outlet section to ensure that the bearing configuration section has a higher pressure than the storage tank.

8. A liquefied gas booster pump, wherein, The liquefied gas booster pump includes: A storage tank having an inlet and an outlet, and storing liquefied gas taken in from the inlet; The housing is disposed within the storage tank and has a liquefied gas delivery path, the liquefied gas delivery path including an intake port that opens toward the storage tank, an outlet port that communicates with the delivery outlet port, and an impeller configuration portion formed between the intake port and the outlet port. An impeller, disposed within the impeller configuration section, is used to draw in the liquefied gas in the storage tank through the liquefied gas delivery path from the inlet and deliver it from the outlet under the action of rotation; as well as A superconducting motor having a motor body disposed within the housing and a motor shaft protruding from the motor body toward the impeller configuration and used to rotate the impeller. The shell has the following: A motor mounting section, which is axially adjacent to the impeller mounting section on the motor shaft and is a space for mounting the motor body; and A cooling flow path is provided to spatially connect the storage tank with the motor mounting section, and to cool the superconducting motor using the liquefied gas. The cooling flow path has: An inflow section, which communicates with the impeller configuration section, and allows the motor configuration section to communicate with the storage tank via the liquefied gas outlet path; and A return path has one end connected to the motor configuration and the other end connected to the impeller configuration, and is used to allow the liquefied gas to return directly from the motor configuration to the impeller configuration.

9. The liquefied gas booster pump according to claim 6, wherein, The pressure reducing device is located outside the storage tank.

10. The liquefied gas booster pump according to claim 7, wherein, The pressure reducing device is located outside the storage tank.

11. The liquefied gas booster pump according to any one of claims 1 to 4 and 8, wherein, The motor shaft protrudes from the suction port into the storage tank. The housing is provided with a support portion that supports the front end of the motor shaft. A radial bearing is provided in the support portion to withstand the radial load of the motor shaft.

12. The liquefied gas booster pump according to any one of claims 1 to 4 and 8, wherein, The impeller is a multi-stage impeller consisting of multiple enclosed impellers spaced apart along the axial direction of the motor shaft. At least one of the plurality of spaces is provided with a radial bearing to bear the radial load of the motor shaft.

13. The liquefied gas booster pump according to any one of claims 1 to 4 and 8, wherein, The housing is equipped with a radial bearing for bearing the radial load of the motor shaft and an axial bearing for bearing the axial load of the motor shaft. The axial bearing is positioned on the opposite side of the motor body relative to the radial bearing.

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