Claims:We claim:
1. A torque tube (100) with anchored radiation shield (204) for a high temperature superconducting (HTS) synchronous machine rotor, the torque tube (100) comprising:
a cylindrical body (102);
a cryostat side torque tube flange (104) formed at cryostat side end of the cylindrical body (102);
a shaft side torque tube flange (106) formed at drive/non-drive shaft side end of the cylindrical body (102); and
an intermediate flange (112) formed at outer central region of the cylindrical body (102) for mounting a radiation shield (204).
a non-drive end flange (108) formed with a knife edge (110) and holes (112) at the non-drive end side of the cylindrical body (102).
2. The torque tube (100) as claimed in claim 1, wherein the torque tube (100) is assembled with the HTS synchronous machine rotor with minimum allowable ovality and eccentricity.
3. The torque tube (100) as claimed in claim 1, wherein the torque tube (100) is made of thermally nonconductive material so as to reduce the conductive heat in-leak in the HTS synchronous machine rotor.
4. The torque tube (100) as claimed in claim 1, wherein torque tube (100) is formed with optimum torsional strength to safely transfer electromagnetic torque generated in the HTS synchronous machine to shafts and ultimately to load even at cryogenic temperatures.
5. The torque tube (100) as claimed in claim 1, wherein the torque tube (100) is able to work in high vacuum environment so that no considerably change occurs in vacuum of the HTS synchronous machine rotor due to degassing of torque tube (100) at steady state.
6. The torque tube (100) as claimed in claim 1, wherein the torque tube (100) is able to maintain overall mechanical integrity at even cryogenic temperatures.
7. A high temperature superconducting (HTS) synchronous machine, comprising:
a torque tube (100) for HTS synchronous machine rotor comprising:
a cylindrical body (102);
a cryostat side torque tube flange (104) formed at cryostat side end of the cylindrical body (102);
a shaft side torque tube flange 106 formed at drive/non-drive shaft side end of the cylindrical body (102); and
an intermediate flange (112) formed at outer central region of the cylindrical body (102) for mounting a radiation shield (204).
8. The HTS synchronous machine as claimed in claim 7, wherein the radiation shield (204) is made of Electrolytic Tough Pitch (ETP) grade copper with outer shining surface.
9. The HTS synchronous machine as claimed in claim 7, wherein the HTS synchronous machine comprises two torque tubes (100-1, 100-2), and wherein drive and non-drive end of the torque tubes (100-1, 100-2) are connected to respective drive and non-drive end shaft (302, 304) at the drive/non-drive shaft side end, while other ends of the torque tubes (100-1, 100-2) are connected to a rotating cryostat (202).
, Description:TORQUE TUBE WITH ANCHORED RADIATION SHIELD IN HIGH-TEMPERATURE SUPERCONDUCTING SYNCHRONOUS MACHINE ROTOR
TECHNICAL FIELD
[0001] The present disclosure, in general, relates to a high temperature superconducting (HTC) synchronous machine and, in particular, relates to torque tube with anchored radiation shield in high temperature superconducting machine rotor.
BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] High temperature superconducting (HTS) synchronous machines typically include but are not limited to, rotary generators, rotary motors, and linear motors. These HTC synchronous machines generally include a stator and a rotor that are electromagnetically coupled. The rotor may include a multi-pole rotor core and one or more coil windings mounted on the rotor core.
[0004] Recently, superconducting coils have been developed for rotors of HTS synchronous machines. The superconducting coils have effectively no resistance and are highly advantageous over conventional rotor coil windings made from copper. However, the superconducting coils are formed of materials that are brittle and hence required to be cooled up to or below a cryogenic temperature, so as to achieve and maintain superconductivity.
[0005] The superconducting coils are kept in cryostat and cooled using a cryocooler provided in a closed loop circuit with the cryostat. In the closed loop circuit, the cryocooler dispels cold gas towards the superconducting coils kept in the crysostat, and receives warm gas collected from the cryostat for cooling.
[0006] Additionally, in the HTS synchronous machines, the transfer of torque to/from load to the HTS synchronous machine rotor is facilitated by two torque tubes, each connected to respective drive end and non-drive end shafts at one end while connected to the rotating cryostat at the other ends. Further, on intermediate flange of the torque tubes, a radiation shield made of Electrolytic Tough Pitch (ETP) grade copper with outer shining surface is mounted. The radiation shield extends a bit large towards non-drive end side of the shaft for reducing the radiation heat in-leak in the HTS synchronous machine rotor. The radiation shield is also provided with a cooling system is also provided for its cooling.
[0007] There are many points to be kept in mind for designing the torque tube. For example, the manufacturing of torque tube is to be from a thermally non-conductive material which includes fibre and resin is very critical because the fibre orientation plays a crucial role in deciding the torsional strength of torque tube. In addition to this, some other critical points are manufacturing of torque tube include minimum allowable ovality and eccentricity with all three flanges, optimum thermal mass along with mechanical strength, optimum thickness of tube for low thermal heat in leak, optimum torsional strength at cryogenic temperatures, inherently low degassing characteristic under high vacuum, and the like.
[0008] Accordingly, there is a need for a torque tube which can address the above mentioned designing requirements.

OBJECTS OF THE DISCLOSURE
[0009] Some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed hereinbelow.
[0010] It is an object of the present disclosure to provide a torque tube with anchored radiation shield for a high temperature superconducting (HTS) synchronous machine rotor.
[0011] It is another object of the present disclosure to provide a torque tube for the HTS synchronous machine rotor with a thermally non-conductive material so as to reduce the conductive heat in-leak in the HTS synchronous machine rotor.
[0012] It is yet another object of the present disclosure to provide a torque tube with different anchoring flange to mount radiation shield.
[0013] It is yet another object of the present disclosure to provide a torque tube with optimum thermal mass along with mechanical strength even at cryogenic temperatures.
[0014] It is yet another object of the present disclosure to provide a torque tube with optimum torsional strength which can safely transfer electromagnetic torque generated in the machine to shafts and ultimately to load even at crytogenic temperatures.
[0015] It is yet another object of the present disclosure to provide and assemble a torque tube with minimum allowable ovality and eccentricity.
[0016] It is yet another object of the present disclosure to provide a system for cooling of radiation shield mounted on separate anchoring flange.
[0017] It is yet another object of the present disclosure to develop a torque tube with a material having inherently low degassing characteristic under high vacuum of the order of 10-6 mbar.
SUMMARY
[0018] This summary is provided to introduce concepts related to a torque tube with anchored radiation shield in high temperature superconducting machine rotor. The concepts are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
[0019] In an embodiment, a torque tube (100) is described with anchored radiation shield for a high temperature superconducting (HTS) synchronous machine rotor. The torque tube includes a cylindrical body; a cryostat side torque tube flange formed at cryostat side end of the cylindrical body; a shaft side torque tube flange formed at drive/non-drive shaft side end of the cylindrical body; and an intermediate flange formed at outer central region of the cylindrical body for mounting a radiation shield.
[0020] In an aspect, the torque tube is assembled with the HTS synchronous machine rotor with minimum allowable ovality and eccentricity.
[0021] In an aspect, the torque tube is made of thermally nonconductive material so as to reduce the conductive heat in-leak in the HTS synchronous machine rotor.
[0022] In an aspect, the torque tube is formed with optimum torsional strength to safely transfer electromagnetic torque generated in the HTS synchronous machine to shafts and ultimately to load even at cryogenic temperatures.
[0023] In an aspect, the torque tube is able to work in high vacuum environment so that no considerably change occurs in vacuum of the HTS synchronous machine rotor due to degassing of torque tube at steady state.
[0024] In an aspect, the torque tube is able to maintain overall mechanical integrity at even cryogenic temperatures.
[0025] In another embodiment, a high temperature superconducting (HTS) synchronous machine is described. The HTS synchronous machine includes a torque tube for HTS synchronous machine rotor. The torque tube includes a cylindrical body; a cryostat side torque tube flange formed at cryostat side end of the cylindrical body; a shaft side torque tube flange formed at drive/non-drive shaft side end of the cylindrical body; and an intermediate flange formed at outer central region of the cylindrical body for mounting a radiation shield.
[0026] In an aspect of the other embodiment, the radiation shield is made of Electrolytic Tough Pitch (ETP) grade copper with outer shining surface.
[0027] In an aspect of the other embodiment, the HTS synchronous machine includes two torque tubes. Further, in said aspect, drive and non-drive end of the torque tubes are connected to respective drive and non-drive end shaft at the drive/non-drive shaft side end, while other ends of the torque tubes are connected to a rotating cryostat.
[0028] Thus, with the present disclosure, the vacuum sleeve is assembled with minimum allowable ovality and eccentricity. Also, the vacuum sleeve can be multiple times detachably connected, on the requirement, to the HTS synchronous machine rotor. Further, the vacuum sleeve described herein is developed with an optimum torsional strength which can safely transfer a portion of electromagnetic torque generated in the HTS synchronous machine to shafts and ultimately to load. Also, the vacuum sleeve described herein is able to maintain mechanical integrity of complete setup and there is no sign of buckling.
[0029] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] The illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and processes that are consistent with the subject matter as claimed herein, wherein:
[0031] FIG. 1 illustrates an exemplary longitudinal cross-section of a torque tube, in accordance with an exemplary embodiment of the present disclosure;
[0032] FIG. 2 illustrates exemplary radiation shield mounting arrangement on the torque tube, in accordance with an exemplary embodiment of the present disclosure; and
[0033] FIG. 3 illustrates an exemplary assembly of the torque tube with anchored radiation shield in a high temperature superconducting (HTS) synchronous machine rotor, in accordance with an exemplary embodiment of the present disclosure.
DETAILED DESCRIPTION
[0034] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0035] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0036] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the “invention” may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the “invention” will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[0037] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.
Exemplary Embodiments:
[0038] Various embodiments are further described herein with reference to the accompanying figures. It should be noted that the description and figures relate to exemplary embodiments, and should not be construed as a limitation to the subject matter of the present disclosure. It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the subject matter of the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the subject matter of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof. Yet further, for the sake of brevity, operation or working principles pertaining to the technical material that is known in the technical field of the present disclosure have not been described in detail so as not to unnecessarily obscure the present disclosure.
[0039] FIG. 1 illustrates an exemplary longitudinal cross-section of a torque tube 100, in accordance with an exemplary embodiment of the present disclosure. The torque tube 100 has a cylindrical body 102 with two ends, say, one being cryostat side end while other being a drive/non-drive shaft side end. At the cryostat side end, the torque tube 100 includes a cryostat side torque tube flange 104, and at the drive/non-drive shaft side end, the torque tube 100 includes a shaft side torque tube flange 106. The cryostat side torque tube flange 104 connects the torque tube 100 to a rotating cryostat using one or more fastening means 108. Similarly, the shaft side torque tube flange 106 connects the torque tube 100 to drive/non-drive end shafts using one or more fastening means 110. In an example, the fastening means 108 and 110 may include, but not limited to, rivets, pins, bolts, screws, nuts, washers, braces, and the like.
[0040] In addition to these two flanges 104 and 106, the torque tube 106 includes an intermediate flange 112 for mounting a radiation shield (shown in FIGS. 2 and 3) using one or more mounting means 114.
[0041] In an exemplary implementation, the torque tube 100 is made of high torsional strength fibre reinforced plastic (FRP) material 116 containing Kevlar fibre along with proportions of G-10 glass in a suitable resin.
[0042] FIG. 2 illustrates an exemplary radiation shield mounting arrangement on the torque tube 100 for the HTS synchronous machine rotor. The radiation shield mounting arrangement shows that the cryostat side torque tube flange 104 is connected with a cryostat 202 for superconducting coils, and that the shaft side torque tube flange 106 is connected to one of the drive/non-drive end shaft.
[0043] Further, the intermediate flange 112 of the torque tube 100 is provided to mount the radiation shield 204 along with radiation shield cooling arrangement 206.
[0044] In an exemplary implementation, after assembly of the torque tube flanges 104 and 106 to shafts and superconducting cryostat 202, the radiation shield 204 made of Electrolytic Tough Pitch (ETP) grade copper with outer shining surface is mounted on the intermediate flange 112.
[0045] FIG. 3 illustrates complete assembly of radiation shield of the HTS synchronous machine rotor with end shafts. As shown in FIG. 3, drive and non-drive end torque tubes 100-1 and 100-2 are connected to respective drive and non-drive end shaft 302, 304 at one end, while the other ends are connected to the rotating cryostat 202. On the intermediate flanges of the drive and non-drive end torque tubes 100-1 and 100-2, the radiation shield 204 is mounted. The radiation shield 204 extends a bit large with an extension 306 towards non-drive end side, i.e., cold helium entry side for reducing the radiation heat in-leak in system/machine. Further, as mentioned above, the cooling arrangement 206 is provided to cool the radiation shield 204 of HTS synchronous machine rotor.
[0046] Thus, with the designing of the torque shaft as per the present disclosure, on intermediate flange of the torque tubes, a radiation shield made of Electrolytic Tough Pitch (ETP) grade copper with outer shining surface is mounted. The radiation shield extends a bit large towards non-drive end side of the shaft for reducing the radiation heat in-leak in the HTS synchronous machine rotor. The radiation shield is also provided with a cooling system is also provided for its cooling.
[0047] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.
[0048] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.
[0049] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.