JP2011252442A - Very low temperature rotary machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a very low temperature rotary machine which can easily perform attaching-detaching work of a component, by improving the heat insulation effect between the impeller side and the driving device side, by restraining a circulating flow of circulating a very low temperature refrigerant around a heat insulation material.SOLUTION: This very low temperature rotary machine 1 includes a rotary shaft 4 for arranging the impeller 2 side for imparting kinetic energy to the very low temperature refrigerant in a heat insulated-cold reserved vacuum vessel, arranging the driving device 3 side for rotatingly driving an impeller 2 outside the vacuum vessel and transmitting rotation of a driving deice 3 to the impeller 2, a journal bearing 5 for supporting the rotary shaft 4, a casing 6 for storing the impeller 2 and fixed to the vacuum vessel, the heat insulation material 7 arranged between the casing 6 and the rotary shaft 4 and between the impeller 2 and the journal bearing 5 and a seal member 8 arranged on a vertical plane to the rotary shaft 4 formed in the heat insulation material 7.

Description

  The present invention relates to a cryogenic rotating machine that sends a cryogenic refrigerant such as liquid nitrogen, liquid helium, and liquid hydrogen, and in particular, a stationary flow path including an inlet / outlet pipe for a cryogenic refrigerant is disposed in a vacuum vessel, and an impeller It is related with the cryogenic rotary machine which can remove the drive device containing this outside a vacuum vessel.

  Cryogenic rotating machines, for example, compressors and pumps for sending cryogenic refrigerants used for cooling superconducting magnets used in fusion reactors and accelerators, slowing down neutrons generated by atomic collisions, etc. A rotating machine such as a turbine. Here, the cryogenic temperature generally means a temperature obtained by using boiling under reduced pressure such as liquid helium and dilution refrigeration. Specifically, the saturation temperature at atmospheric pressure is 4K for liquid helium, 20K for hydrogen gas, and 80K for nitrogen gas, from which the temperature lower than the saturation temperature obtained by decompressing each refrigerant is extremely low. Equivalent to. The cryogenic refrigerant means a cryogenic gas or liquid, and includes, for example, liquid nitrogen, liquid helium, liquid hydrogen, and their vaporized gases. In such a cryogenic rotating machine, generally, an impeller side that imparts kinetic energy to a cryogenic refrigerant is arranged in a vacuum container that is insulated and cooled, and a driving device side that rotates the impeller is arranged outside the vacuum container (for example, a patent) Reference 1 and Patent Document 2). That is, the impeller side is disposed in a low-temperature refrigerant atmosphere, and the drive device side is disposed in a normal-temperature refrigerant atmosphere. Therefore, in order to maintain or improve the performance and efficiency of the cryogenic rotating machine, it is important to insulate between the impeller side and the drive device side to reduce the amount of heat penetration into the low temperature side.

  The cryogenic rotating machine described in Patent Document 1 operates an impeller provided at one end of a rotating shaft in a cryogenic region and holds a bearing portion supporting the rotating shaft in a state higher than the liquid nitrogen temperature level. A cryogenic rotating machine, in which an impeller, a heat insulating material inserted between a back surface portion of the impeller and a bearing portion, and a part of a rotating shaft are housed in a casing, and a part of the heat insulating material is a casing. A cooling gas flow path for cooling the heat insulating material and the casing is formed by supplying a fluid of the same quality as the working fluid cooled to the liquid nitrogen temperature level.

  The cryogenic rotating machine described in Patent Document 2 is installed inside a vacuum vessel, has a built-in turbine impeller, and has an adiabatic expansion device that rotationally drives the turbine impeller when a cryogenic gas is adiabatically expanded. A variable nozzle mechanism that changes the throat area of the cryogenic gas introduced into the turbine impeller by driving a nozzle member disposed in the vicinity of the outer end of the adiabatic expansion device by a driving force from a driving member installed outside the container It is an attached expansion turbine. In such an expansion turbine, a heat insulating material is disposed between the turbine impeller and the bearing and a pressing spring is disposed on the back surface of the heat insulating material to urge the heat insulating material in the axial direction, thereby causing gas leakage from the gaps between the components. Try to prevent. In addition, an O-ring that seals a gap with the bearing is disposed on a side surface portion (a surface extending in the axial direction of the rotating shaft) of the heat insulating material.

JP-A-6-193598 JP 2008-248748 A

  However, in the cryogenic rotating machine described in Patent Document 1, the heat insulating member disposed on the back surface of the impeller can insulate between the impeller side in the low-temperature refrigerant atmosphere and the drive device side in the normal-temperature refrigerant atmosphere. However, it is not possible to suppress the atmospheric gas from flowing through the gap between the rotating shaft and the heat insulating material, between the heat insulating material and the casing, or the like to the drive device side. In addition, when the atmospheric gas flows to the drive device side, the temperature of the component parts on the drive device side is lowered, which may cause the performance and efficiency of the cryogenic rotating machine to be lowered. Such a problem becomes prominent particularly when a circulation flow in which the atmospheric gas circulates around the heat insulating material occurs.

  Further, the expansion turbine described in Patent Document 2 has a problem that the sealing performance is basically low because the sealing is performed by the biasing force of the holding spring. Therefore, even if an O-ring is arranged between the heat insulating material and the bearing, if the atmospheric gas leaks, the O-ring is cooled and solidified, and its function is lost and the sealing performance is deteriorated. There was a problem to do. Furthermore, when a circulation flow in which the ambient gas circulates around the heat insulating material is generated, the pressing spring is also cooled, and there is a problem that the sealing performance is further deteriorated by losing the urging force.

  Further, in the cryogenic rotating machine described above, a stationary flow path including an inlet / outlet pipe for a cryogenic refrigerant is disposed in the vacuum vessel for maintenance and the like, so that the driving device including the impeller can be removed from the vacuum vessel. It is configured. Therefore, as described in Patent Document 2, when a seal is disposed on the side surface (surface extending in the axial direction) of the rotating shaft, the sealing material, scraps, and the like are removed from the casing when a component such as an impeller is attached or detached. There is a risk of falling into the system piping, and it is necessary to carefully attach and detach components, which takes time.

  The present invention was devised in view of the above-described problems, suppresses the circulation flow in which ambient gas circulates around the heat insulating material, improves the heat insulating effect between the impeller side and the drive device side, It is an object of the present invention to provide a cryogenic rotating machine capable of easily attaching and detaching components.

  According to the present invention, in the cryogenic rotating machine in which the impeller side that imparts kinetic energy to the cryogenic refrigerant is disposed in a thermally insulated vacuum vessel, and the drive device side that rotationally drives the impeller is disposed outside the vacuum vessel, A rotating shaft that transmits the rotation of the driving device to the impeller, a bearing that supports the rotating shaft, a casing that houses the impeller and is fixed to the vacuum vessel, and between the casing and the rotating shaft; Provided is a cryogenic rotating machine comprising: a heat insulating material disposed between an impeller and the bearing; and a seal member disposed on a surface perpendicular to the rotating shaft formed in the heat insulating material. Is done.

  The heat insulating material has, for example, a flange portion that can be locked to an opening formed in the casing, and the flange portion is sandwiched between the bearing and the casing. It arrange | positions at the single side | surface or both surfaces of the said flange part.

  The seal member is made of a soft metal such as indium. The flange portion may be formed so that the soft metal does not protrude from the flange portion when extended.

  Moreover, when the said sealing member is arrange | positioned at the one surface by the side of the said bearing of the said flange part, you may make it the opening part which penetrates both surfaces in the radial direction outer side rather than the said heat insulating material of the said bearing not be formed.

  In addition, the heat insulating material has a flange portion that can be locked to an opening formed in the casing, the flange portion is sandwiched between the bearing and the casing, It may be made of a soft metal and disposed between the flange portion and the bearing.

  According to the cryogenic rotating machine according to the present invention described above, the heat insulating material is disposed between the impeller and the bearing, and the sealing member is disposed on the surface perpendicular to the rotation shaft formed in the heat insulating material, whereby the heat insulating material. The outer surface can be sealed, and even when components are attached and detached during maintenance, etc., sealing members and scraps can be left on the placement surface and dropped on the casing. The risk of being mixed into the system piping can be reduced. Therefore, it is possible to suppress the circulation flow in which the ambient gas circulates around the heat insulating material, to improve the heat insulating effect between the impeller side and the driving device side, and to reduce the heat intrusion amount to the low temperature side. At the same time, it is possible to easily attach and detach components.

  In particular, by using a soft metal such as indium as the sealing member, the sealing member can be effectively brought into close contact with the arrangement surface of the sealing member, and the sealing performance even when the sealing member is exposed to a low temperature atmosphere. Can be demonstrated. Further, even when the seal member is crushed and brought into close contact like a soft metal, the seal member is placed on a surface perpendicular to the rotating shaft so that the seal member is dropped into the casing when the component is attached or detached. Thus, it is possible to easily perform maintenance or the like.

1 is an overall configuration diagram of a cryogenic rotary machine according to a first embodiment of the present invention. FIG. 2 is an enlarged view around a heat insulating material shown in FIG. 1. It is a figure for demonstrating the flow of the gas produced in the circumference | surroundings of a heat insulating material, (a) shows the comparative example which uses the presser spring of a prior art, (b) shows 1st embodiment shown in FIG. Yes. It is a figure which shows the state which removed some components of the cryogenic rotary machine. It is an enlarged view of the periphery of a heat insulating material which shows other embodiment of the cryogenic rotary machine which concerns on this invention, (a) is 2nd embodiment, (b) is 3rd embodiment, (c) is 4th embodiment. , (D) shows the fifth embodiment.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 4. Here, FIG. 1 is an overall configuration diagram of the cryogenic rotating machine according to the embodiment of the present invention. FIG. 2 is an enlarged view of the periphery of the heat insulating material shown in FIG. 3 is an enlarged view of the periphery of the heat insulating material. FIG. 3A shows a comparative example using a conventional presser spring, and FIG. 3B shows the first embodiment shown in FIG. FIG. 4 is a view showing a state in which some of the components of the cryogenic rotating machine are removed. 1 and 4, the illustration of the vacuum vessel is omitted.

  The cryogenic rotating machine 1 according to the first embodiment of the present invention, as shown in FIGS. 1 and 2, is disposed in a vacuum container in which the impeller 2 side that imparts kinetic energy to the cryogenic refrigerant is insulated and kept cool. The drive device 3 side for rotationally driving the impeller 2 is arranged outside the vacuum vessel, and accommodates the rotary shaft 4 that transmits the rotation of the drive device 3 to the impeller 2, the journal bearing 5 that supports the rotary shaft 4, and the impeller 2. In addition, the casing 6 fixed to the vacuum vessel, the heat insulating material 7 disposed between the casing 6 and the rotating shaft 4 and between the impeller 2 and the journal bearing 5, and the rotating shaft 4 formed on the heat insulating material 7. And a seal member 8 disposed on a surface perpendicular to the surface.

  As shown in FIG. 1, the impeller 2 is connected to the tip of the rotating shaft 4 and is accommodated in the casing 6. A cryogenic refrigerant suction port 61 is formed on the upstream side of the impeller 2 on the concentric shaft, and a cryogenic refrigerant to which kinetic energy is imparted by centrifugal force is sent to the radial outer periphery of the impeller 2. A scroll portion 62 is formed. The scroll portion 62 communicates with an outlet pipe 63 connected to the casing 6.

  The driving device 3 is, for example, a non-contact type motor that includes a rotor 31 and a stator 32. The rotor 31 and the stator 32 are configured by, for example, an induction motor, a generator, or the like. The rotor 31 is disposed on the rotating shaft 4 and the stator 32 is disposed on the housing 9. The rotor 31 generates rotational torque by interaction with the stator 32 and is rotationally driven together with the rotating shaft 4.

  The rotary shaft 4 is supported by a pair of journal bearings 5 and 10 disposed so as to sandwich the drive device 3 and a thrust bearing 11 disposed on the back surface of the journal bearing 5. For example, magnetic bearings are employed as these bearings, and the rotating shaft 4 is supported in a non-contact state. Moreover, the part located between the impeller 2 of the rotating shaft 4 and the journal bearing 5 is formed in a thin hollow cylindrical shape so that heat transfer between the impeller 2 side and the drive device 3 side is difficult. It is configured.

  Here, since the inside of the housing 9 has a structure that can be filled with the vaporized gas of the cryogenic refrigerant, an oil-free configuration is preferable. Therefore, it is preferable to employ non-contact type bearings for the driving device 3 and the rotating shaft 4. A gas bearing may be adopted as the bearing instead of the magnetic bearing. In addition, a work space 91 for connecting wirings and pipes (not shown) to components such as the internal driving device 3 is formed in the upper part of the housing 9, and is closed by a lid member 92. Although not shown, a cooling jacket capable of supplying and circulating cooling water may be disposed on the wall surface of the housing 9 facing the driving device 3.

  The journal bearing 5 has a substantially disk shape having an opening 51 through which the rotary shaft 4 is inserted at the center. Further, a recess 52 that accommodates a part of the heat insulating material 7 may be formed on the outer periphery of the opening 51. The journal bearing 5 is sandwiched between the casing 6 and the housing 9 as shown in FIG. The other journal bearing 10 is inserted and fixed to the rear end side of the rotating shaft 4.

  As shown in FIG. 1, the casing 6 includes a main body 6 a having an opening 64 that accommodates part of the impeller 2 and the rotating shaft 4, and an enlarged diameter portion 6 b formed on the outer periphery of the main body 6 a. Have The main body 6 a is formed with the above-described suction port 61 and scroll portion 62 so as to communicate with the opening 64. Moreover, the part which accommodates the rotating shaft 4 of the main-body part 6a is formed in the thin hollow cylindrical shape, and it is comprised so that it may become difficult to transfer heat between the impeller 2 side and the drive device 3 side. Further, a recess 65 for accommodating the journal bearing 5 may be formed on the outer periphery of the opening 64 of the main body 6a on the drive device 3 side. Moreover, the enlarged diameter part 6b is fixed to the wall surface of the vacuum vessel which is not illustrated. That is, the casing 6 is inserted from the opening formed on the wall surface of the vacuum vessel on the impeller 2 side of the main body 6a, and the enlarged diameter portion 6b is disposed on the wall surface of the vacuum vessel so as to cover the opening, and is fixed from the outside. It is comprised so that.

  As shown in FIGS. 1 and 2, the heat insulating material 7 is disposed between the impeller 2 and the journal bearing 5, and transfers heat between a low temperature atmosphere in the vacuum vessel and a normal temperature atmosphere outside the vacuum vessel. Suppress. For the heat insulating material 7, for example, a material having low thermal conductivity and high durability against a cryogenic atmosphere such as glass fiber reinforced plastic or ceramics is employed.

  The heat insulating material 7 is formed in a substantially cylindrical shape that can be disposed between the casing 6 and the rotating shaft 4 and between the impeller 2 and the journal bearing 5, and is related to an opening 64 formed in the casing 6. A flange portion 71 that can be stopped is provided, and the flange portion 71 is sandwiched between the journal bearing 5 and the casing 6. Specifically, the lower surface of the flange portion 71 is engaged with a recess 65 formed in the main body portion 6 a of the casing 6, and the upper surface of the flange portion 71 is accommodated in the recess 52 formed in the journal bearing 5. Further, a stepped portion 72 may be formed inside the heat insulating material 7 so as to be along the surfaces of the rotary shaft 4 and the journal bearing 5.

  The seal member 8 is disposed so as to prevent a circulation flow generated around the heat insulating material 7 and not to disturb maintenance work. In order to exert such a function, the seal member 8 is disposed on a surface perpendicular to the rotating shaft 4 formed in the heat insulating material 7. Specifically, the seal member 8 is disposed on the upper surface, the lower surface, or the upper and lower surfaces of the flange portion 71 formed on the heat insulating material 7. In the first embodiment shown in FIGS. 1 and 2, the seal member 8 is positioned by an annular groove 73 formed on the upper surface of the flange portion 71.

  Note that the upper surface and the lower surface of the flange portion 71 described above correspond to surfaces perpendicular to the rotating shaft 4 formed on the heat insulating material 7, but “vertical” does not only mean complete vertical, but also the seal member 8. This is intended to include the case of having an inclination that does not fall into the casing 6. For example, in order to suppress the fall of the seal member 8, the outside of the upper surface of the flange portion 71 may be made higher than the inside, or the inside of the lower surface of the flange portion 71 may be made higher than the outside. At this time, the surface facing the flange portion 71 is also formed along the surface of the flange portion 71.

  The seal member 8 is made of a soft metal such as annular indium or lead. By using such a soft metal, it can be crushed and extended between the heat insulating material 7 and the journal bearing 5, the adhesion rate can be improved, and the sealing performance can be improved. In particular, by selecting a material that is resistant to low temperatures such as indium, it is possible to suppress a decrease in sealing performance even when the seal member 8 is exposed to a low temperature atmosphere. Therefore, the airtightness between the heat insulating material 7 and the journal bearing 5 can be improved and maintained, and the circulation flow generated around the heat insulating material 7 can be suppressed.

  Further, the flange portion 71 of the heat insulating material 7 is formed so that the soft metal does not protrude from the flange portion 71 during the extension. Specifically, as shown in FIG. 2, the flange portion 71 of the heat insulating material 7 has a width R in the radial direction, and this width R is an upper surface of the flange portion 71 when the soft metal is extended. It is set not to stick out. By setting the width R of the flange portion 71 in this way, the seal member 8 can be held between the flange portion 71 and the journal bearing 5, and the heat insulating material 7 can be attached and detached during maintenance or the like. Also, the drop of the seal member 8 can be effectively suppressed.

  Here, the circulation flow generated around the heat insulating material 7 will be described with reference to FIG. The comparative example shown in FIG. 3A is a comparative example using a holding spring 8r used in the prior art instead of the seal member 8 of the first embodiment.

  In the comparative example shown in FIG. 3A, the flange portion 71r of the heat insulating material 7r is formed so that the radial width is shorter than that in the first embodiment shown in FIG. A holding spring 8r is inserted between the flange portion 71r and the journal bearing 5r. Further, the journal bearing 5r is formed with an opening 53 that penetrates both the upper and lower surfaces radially outward from the heat insulating material 7r. The opening 53 is for reducing pressure fluctuations generated between the impeller side and the drive device side.

  In this comparative example, since the opening 53 is formed, the cryogenic refrigerant gas easily flows into the gap between the heat insulating material 7r and the casing 6r. In addition, since pressure distribution is likely to occur on the back surface of the impeller 2r and the sealing performance of the presser spring 8r is low, gas is generated in the gap between the heat insulating material 7r and the journal bearing 5r and the gap between the thrust bearing 11r and the journal bearing 5r. The structure is easy to flow. Further, when the holding spring 8r is exposed to a low temperature atmosphere, the biasing force is lost and the sealing performance is deteriorated, so that the gas can flow more easily. As a result, as shown by the arrow in FIG. 3A, a circulating flow in which the atmospheric gas circulates around the heat insulating material 7r is generated. Such a circulating flow reduces the heat insulating effect of the heat insulating material 7r and causes the performance and efficiency of the entire apparatus to decrease.

  On the other hand, in the first embodiment shown in FIG. 3B, the journal bearing 5 has the above-described configuration, and the journal bearing 5 is not formed with an opening that penetrates both surfaces radially outward from the heat insulating material 7. Therefore, even when a pressure fluctuation occurs between the impeller 2 side and the drive device 3 side or when a pressure distribution occurs on the back surface of the impeller 2, the heat insulating material 7 and the journal bearing 5 are separated by the seal member 8. Since the gap is hermetically sealed, it is difficult for the atmospheric gas to flow around the heat insulating material 7, and the generation of the circulating flow can be suppressed. In addition, gas may escape to the drive device 3 side through the gap between the casing 6 and the heat insulating material 7 and the gap between the casing 6 and the journal bearing 5, but the amount of the gas is very small. Not enough to reduce the heat insulation effect.

  Next, the first embodiment described above will be described with reference to FIG. 4 for the case where the components of the cryogenic rotating machine 1 are attached and detached during maintenance or the like.

  As shown in FIG. 4, the cryogenic rotating machine 1 includes a stationary flow path (for example, an inlet 61, an outlet pipe 63, etc.) including an inlet / outlet pipe for a cryogenic refrigerant disposed in a vacuum vessel, It is comprised so that the drive device 3 containing can be removed out of a vacuum vessel. That is, the components of the cryogenic rotating machine 1 (the impeller 2, the driving device 3, the rotating shaft 4, the journal bearing 5, the heat insulating material 7, the housing, while the casing 6 is left on the vacuum container side (not shown) during maintenance and inspection. The body 9 or the like) can be removed. With this configuration, the cryogenic rotating machine 1 can be easily maintained. Even when the cryogenic rotating machine 1 fails, the components of the cryogenic rotating machine 1 can be removed from the casing 6 and easily replaced.

  In the first embodiment, since the seal member 8 is disposed between the flange portion 71 of the heat insulating material 7 and the journal bearing 5, the journal bearing 5 is removed when the components of the cryogenic rotating machine 1 are removed. And the sealing member 8 is also removed together with the heat insulating material 7. Therefore, even when a soft metal such as indium is used for the seal member 8, it can be easily removed together with other components, and the drop of the seal member 8 into the casing 6 can be reduced. In addition, by forming the flange portion 71 so that the seal member 8 does not protrude from the flange portion 71, the dropping of the seal member 8 can be further reduced.

  Subsequently, a cryogenic rotating machine according to another embodiment of the present invention will be described. Here, FIG. 5 is an enlarged view around the heat insulating material showing another embodiment of the cryogenic rotating machine according to the present invention, (a) is the second embodiment, (b) is the third embodiment, ( c) shows a fourth embodiment, and (d) shows a fifth embodiment. In addition, in each figure, about the same component as 1st embodiment shown in FIG. 1, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

  In the second embodiment shown in FIG. 5A, the seal member 8 is arranged on the lower surface of the flange portion 71 of the heat insulating material 7. That is, the seal member 8 is disposed between the flange portion 71 and the casing 6. Further, when a soft metal is used for the seal member 8, the seal member 8 is disposed at a position that does not protrude from the upper surface of the casing 6 (a surface perpendicular to the rotating shaft 4) when the soft metal is crushed and extended. Is done. When the seal member 8 is disposed on the lower surface of the flange portion 71, gas does not enter the gap between the casing 6 and the journal bearing 5, so that the outer diameter of the journal bearing 5 is more radially outward than the heat insulating material 7 r. You may make it form the opening part which penetrates both surfaces.

  When the sealing member 8 is arranged between the flange portion 71 and the casing 6 as described above, the sealing member 8 remains on the casing 6 side when the components are removed during maintenance of the cryogenic rotating machine 1 or the like. However, since the seal member 8 is disposed on a surface perpendicular to the rotation shaft 4, the seal member 8 can be removed relatively easily after the components of the cryogenic rotating machine 1 are removed. it can.

  In the third embodiment shown in FIG. 5B, the sealing members 8 are arranged on both the upper and lower surfaces of the flange portion 71 of the heat insulating material 7. That is, the seal member 8 is disposed between the flange portion 71 and the casing 6 and between the flange portion 71 and the journal bearing 5. The third embodiment is a combination of the first embodiment and the second embodiment, and has the same effects as these. Here, the position of the seal member 8 on the upper and lower surfaces is made to coincide with the axial direction of the rotary shaft 4, but the seal member 8 on the upper surface is arranged radially inside the seal member 8 on the lower surface. May be.

  In the fourth embodiment shown in FIG. 5C, the seal member 8 is arranged on the upper surface of the flange portion 71 of the heat insulating material 7 as in the first embodiment, but the seal member 8 is positioned. An annular groove 73 is formed in the journal bearing 5. Even with this configuration, the same effects as those of the first embodiment can be obtained.

  In the fifth embodiment shown in FIG. 5 (d), the seal member 8 is arranged on the lower surface of the flange portion 71 of the heat insulating material 7 as in the second embodiment, but the seal member 8 is positioned. An annular groove 73 is formed in the casing 6. Even with this configuration, the same effects as those of the second embodiment can be obtained.

  Although not shown, in the third embodiment, an annular groove 73 for positioning the seal member 8 may be formed in the journal bearing 5 and the casing 6.

  The present invention is not limited to the above-described embodiment, and an O-ring may be used as the sealing member 8. When the sealing member 8 is disposed on both surfaces of the flange portion 71, one sealing member 8 is the O-ring. Needless to say, various modifications can be made without departing from the spirit of the present invention, such as the sealing member 8 may be made of a soft metal.

DESCRIPTION OF SYMBOLS 1 ... Cryogenic rotating machine 2 ... Impeller 3 ... Drive apparatus 4 ... Rotating shaft 5, 10 ... Journal bearing 6 ... Casing 6a ... Main-body part 6b ... Diameter-expanding part 7 ... Heat insulating material 8 ... Seal member 9 ... Case 11 ... Thrust Bearing 31 ... Rotor 32 ... Stator 51, 53 ... Opening 52 ... Recess 61 ... Suction port 62 ... Scroll part 63 ... Outlet pipe 64 ... Opening 65 ... Recess 71 ... Flange 72 ... Stepped portion 73 ... Annular groove 91 ... Work Space 92 ... Lid member

Claims (6)

In the cryogenic rotating machine in which the impeller side that imparts kinetic energy to the cryogenic refrigerant is disposed in a heat-insulated and cooled vacuum vessel, and the driving device side that rotates the impeller is disposed outside the vacuum vessel,
A rotating shaft for transmitting rotation of the driving device to the impeller;
A bearing for supporting the rotating shaft;
A casing that houses the impeller and is fixed to the vacuum vessel;
A heat insulating material disposed between the casing and the rotating shaft and between the impeller and the bearing;
A seal member disposed on a surface perpendicular to the rotation axis formed in the heat insulating material;
A cryogenic rotating machine characterized by comprising: The heat insulating material has a flange portion that can be locked to an opening formed in the casing,
The flange portion is sandwiched between the bearing and the casing,
The seal member is disposed on one side or both sides of the flange portion,
The cryogenic rotary machine according to claim 1.   The cryogenic rotary machine according to claim 1, wherein the seal member is made of a soft metal.   4. The cryogenic rotary machine according to claim 3, wherein the flange portion is formed so that the soft metal does not protrude from the flange portion when extended.   When the seal member is disposed on one surface of the flange portion on the bearing side, an opening that penetrates both surfaces is formed outside the heat insulating material of the bearing in a radial direction. 2. The cryogenic rotating machine according to 2. The heat insulating material has a flange portion that can be locked to an opening formed in the casing,
The flange portion is sandwiched between the bearing and the casing,
The seal member is made of a soft metal and disposed between the flange portion and the bearing.
The cryogenic rotary machine according to claim 1.