Fluid machine and underwater vehicle

Abstract

Fluid machine (8), comprising: a shaft portion (3) extending in an axial direction; a shell (50) provided to surround the shaft portion and having a diameter decreasing from an upstream side on one side in the axial direction to a downstream side on another side in the axial direction, wherein a flow path is formed between the shell and the shaft portion and has a flow path cross-sectional area decreasing towards the downstream side, a propeller (10A, 10B) rotatably provided about an axis (O) between the shaft portion and the shell and configured to pump a fluid from the upstream side toward the downstream side; and a motor (80, 90) associated with the propeller, the motor including a rotor (82, 130) having an annular shape and fixed to an outer peripheral portion of the propeller and housed in the shroud, and a stator (100) having an annular shape surrounding the rotor and fixed in the casing, wherein the motor is a conical motor in which the diameters of the rotor and the stator decrease from the upstream side to the downstream side, and the fluid machine is characterized in that the shell includes a plurality of longitudinal sections (61, 62, 63) of the shell which are divided into several parts in the axial direction, and the fluid machine further includes a coupling portion (70) configured to couple the plurality of longitudinal portions (61, 62, 63) in the axial direction, and the coupling portion has a convex curved shape protruding from an outer surface of the shell, and the cross-section of the coupling section along the outer surface of the shroud represents a symmetrical airfoil, the upstream side being a leading edge and the downstream side being a trailing edge.

Description

[0001] The present disclosure relates to a fluid machine and an underwater vehicle.

[0002] For example, an outer peripheral drive thruster is described in US Pat. No. 8,074,592 B2 as an example of a fluid machine. The thruster includes a casing having a tubular shape formed around the shaft and propellers arranged coaxially on the inside of the casing.

[0003] Motors are housed in the shroud. Each motor includes a rotor provided on an outer peripheral portion of the propeller and a stator surrounding the rotor on the outer peripheral side. The motor and stator each have a tubular shape, with the outer and inner surfaces parallel to the axis.

[0004] These engines implement an outer peripheral drive of the propellers to pump a fluid axially within the shroud.

[0005] Further prior art can be found in document US 5 607 329 A which describes an integrated engine / ship propulsion system, in document CN 1 12 061 357 A which describes a pump jet propeller without a drive shaft, in document FR 2 927 605 A1 which describes a hydraulic propeller with an improved circumferential rotor. Brief description of the invention

[0006] When a fluid is pumped through the propellers, the flow velocity of the fluid increases, causing the flow of the fluid to narrow in the radial direction toward the inside. In view of this, a flow path along which such a fluid flows preferably has a shape correspondingly narrowed toward the downstream side, that is, the flow path has a flow path cross-sectional area that decreases toward the downstream side. However, the thrust apparatus described above in Patent Document 1 is configured to have the flow path cross-sectional area on the inside of the shroud toward the downstream side. Thus, the configuration is undesirable in terms of propeller efficiency.

[0007] Second, implementing the outer peripheral drive requires locating the motors within the casing, and thus, space must be provided within the casing to accommodate the motors. However, enlarging the casing, which forms the outer shape of the thruster, leads to an increase in the overall volume of the thruster and is therefore undesirable.

[0008] The present disclosure is intended to solve the problems described above, and an object of the present disclosure is to provide a fluid machine and an underwater vehicle that can be made compact and can also achieve improvement in efficiency.

[0009] The present invention is defined by the subject matters of the independent claims. The subclaims describe preferred embodiments. To solve the problems described above, a fluid machine according to the invention includes: a shaft portion extending in an axial direction; a shroud provided to surround the shaft portion and having a diameter that decreases axially from an upstream side on one side to a downstream side on another side, a flow path formed between the shroud and the shaft portion and having a flow path cross-sectional area that decreases toward the downstream side; a propeller rotatably provided around an axis between the shaft portion and the shroud and configured to pump a fluid from the upstream side toward the downstream side;and a motor provided in correspondence with the propeller, the motor comprising a rotor having an annular shape and fixed to an outer peripheral portion of the propeller and accommodated in the shroud, and a stator having an annular shape, surrounding the rotor and fixed in the shroud, the motor being a conical motor in which the diameter of the rotor and the stator decreases from the upstream side to the downstream side;

[0010] The present disclosure can provide a fluid machine and an underwater vehicle that can be made compact and also achieve improvement in efficiency. Brief description of the drawings Fig. 1 is a perspective view of the rear portion of an underwater vehicle according to an embodiment of the present invention. Fig. 2 is a vertical cross-sectional view of a thruster according to the embodiment of the present invention. Fig. 3 is an enlarged view of a main part in Fig. 2. Fig. 4 illustrates suction-side pressure distributions of rotor blades in propellers of the thrust apparatus according to the embodiment, wherein Fig. 4(a) is a view illustrating a suction-side pressure distribution of a first moving blade, and Fig. 4(b) is a view illustrating a suction side pressure distribution of a second blade. Fig. 5 is a vertical cross-sectional view of a coupling portion disposed on an outer surface of a shell. Fig. 6 is a schematic diagram of the coupling portion disposed on the outer surface of the shell, viewed from an outer side in the radial direction. Fig. 7 is a cross-sectional view perpendicular to an axis of a conical engine taken along the line VII-VII in Fig. 3. Fig. Figure 8 is a vertical cross-sectional view including the axis of the conical engine, taken along the line VIII-VIII in Fig. 7. Fig. 9 is a view of a coil layer constituting a coil of the conical motor, viewed from the outside in the radial direction. Fig. 10 is a partially enlarged view of Fig. 3 to illustrate the attachment structure of a conical stator to an outer peripheral ring. Fig. 11 is a two-dimensional view illustrating a permanent magnet of a conical rotor. Fig. 12 is a vertical cross-sectional view of a conical stator according to a first embodiment. Fig. 13 is a vertical cross-sectional view of a conical stator according to a second embodiment. Description of embodiments<Allgemeine Konfiguration des Unterwasserfahrzeugs>

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As shown in Fig. 1 and Fig. 2, an underwater vehicle 1 includes a vehicle body 2 and a thruster 8. <Fahrzeugkörper>

[0012] The vehicle body 2 is formed by a pressure-resistant container extending along an axis O. The vehicle body 2 accommodates various devices, power supply, communication devices, sensors and the like, which are required, for example, for driving underwater. <schubapparat>

[0013] In a rear portion of the vehicle body 2, the thruster 8 is provided integrally with the vehicle body 2. The thruster 8 is a device for propelling the underwater vehicle 1 underwater.

[0014] The thruster 8 includes a shaft portion 3, a first propeller 10A, a second propeller 10B, bearing portions 40, a shroud 50, coupling portions 70, struts 78, a tubular motor 80, and a conical motor 90. <wellenabschnitt>

[0015] As in Fig. 2, the shaft portion 3 is integrally provided in the rear portion of the vehicle body 2. The shaft portion 3 may be part of the vehicle body 2. The shaft portion 3 has a rod shape extending along the axis O. The shaft portion 3 of the present embodiment has a truncated cone shape with a diameter that decreases from one side in the axis O direction (front side of the vehicle body 2) to the other side in the axis O direction (rear side of the vehicle body 2). A surface of the shaft portion 3 facing an outer side in the radial direction is a shaft outer surface 3a, which has a conical shape with a diameter that decreases toward the other side in the axis O direction.

[0016] The receiving grooves 5 formed on the shaft portion 3 are recessed in the radial direction from the shaft outer surface 3a to an inner side and extend annularly in the circumferential direction. Two receiving grooves 5 are formed at an interval in the axis-O direction.

[0017] In particular, as in Fig. 3, a surface facing the outer side in the radial direction at the bottom of each receiving groove 5 is a groove bottom surface 5a. The groove bottom surface 5a forms a cylindrical shape around the axis O.

[0018] A surface forming the receiving groove 5 on one side in the axis-O direction is an upstream groove surface 5b. The upstream groove surface 5b has a flat shape perpendicular to the axis O and faces the other side in the axis-O direction. The upstream roller surface 5b extends annularly around the axis O.

[0019] A surface forming the receiving groove 5 on the other side in the axis O direction is a downstream groove surface 5c. The downstream groove surface 5c has a flat shape perpendicular to the axis O and faces one side in the axis O. The downstream groove surface 5c extends annularly around the axis O. The downstream groove surface 5c is parallel to the upstream groove surface 5b. <Erster Propeller und zweiter Propeller>

[0020] As in Fig. 2 and Fig. As illustrated in Figure 3, the first propeller 10A and the second propeller 10B are arranged on an outer peripheral side of the shaft portion 3 and are relatively rotatable about the axis O with respect to the shaft portion 3. The first propeller 10A includes an inner peripheral ring 11, a first blade 20A, and an outer peripheral ring 30. The second propeller 10B includes an inner peripheral ring 11, a second blade 20B, and an outer peripheral ring 30. <innenumfangsring>

[0021] The inner peripheral ring 11 is a member having an annular shape around the axis O. The inner peripheral ring 11 of the first propeller 10A is received in the receiving groove 5 on one side in the axis O direction. The inner peripheral ring 11 of the second propeller 10B is received in the receiving groove 5 on the other side in the axis O direction.

[0022] As in Fig. 3, the inner peripheral ring 11 includes a ring inner surface 12, an upstream end surface 13, a downstream end surface 14, and an outer peripheral flow path surface 15.

[0023] The ring inner surface 12 forms an inner surface of the inner circumferential ring 11. The ring inner surface 12 forms a cylindrical shape facing the groove bottom surface 5a throughout the entire circumferential direction. The inner diameter of the ring inner surface 12 is set to be larger than the outer diameter of the groove bottom surface 5a.

[0024] The upstream end surface 13 is a surface of the inner circumferential ring 11 facing one side in the axis-O direction, and is arranged on the other side of the upstream groove surface 5b in the axis-O direction with a clearance therebetween.

[0025] The downstream end surface 14 is a surface of the inner circumferential ring 11 facing the other side in the axis-O direction, and is arranged on one side of the downstream groove surface 5c in the axis-O direction with a clearance therebetween.

[0026] The outer peripheral flow path surface 15 forms an outer surface of the inner peripheral ring 11 facing the outside in the radial direction. The outer peripheral flow path surface 15 forms a tapered shape with a diameter that decreases toward the other side in the axis O direction. The outer peripheral flow path surface 15 extends continuously with the shaft outer surface 3a. <Erste Laufschaufel 20A und zweite Laufschaufel 20B>

[0027] The first moving blade 20A is provided so as to extend radially outward from the outer peripheral flow path surface 15 of the inner peripheral ring 11 of the first propeller 10A. The second moving blade 20B is provided so as to extend radially outward from the outer peripheral flow path surface 15 of the inner peripheral ring 11 of the second propeller 10B. A plurality of the first moving blades 20A and the second moving blades 20B are provided at a pitch in the circumferential direction. The dimension of the first moving blade 20A and the second moving blade 20B in the axis-O direction is smaller than the dimension of the inner peripheral ring 11 in the axis-O direction.

[0028] The cross-sectional shapes of the first moving blade 20A and the second moving blade 20B, which intersect in the radial direction, are one moving blade shape. Edge portions of the first moving blade 20A and the second moving blade 20B on one side in the axis-O direction are leading edges on an upstream side. Edge portions of the first moving blade 20A and the second moving blade 20B on the other side in the axis-O direction are trailing edges on a downstream side. The one side and the other side in the axis-O direction are hereinafter referred to simply as the "upstream side" and the "downstream side," respectively.

[0029] Now, the structure of the first moving blade 20A and the second moving blade 20B will be described with reference to Fig. 4 described in detail. Fig. 4 illustrates pressure distributions on a suction side in a case where the first moving blade 20a and the second moving blade 20b rotate at a predetermined speed.

[0030] As in Fig. As illustrated in Fig. 4(a), in the pressure distribution on the suction side of the first moving blade 20a, a region with the highest pressure, that is, a region with the largest load, is formed on the leading edge side and the outer side in the radial direction. A portion on the inner side in the radial direction does not have a large load portion, and thus the load is low throughout the entire portion in the axis-O direction.

[0031] As in Fig. As illustrated in Figure 4(b), in the pressure distribution on the suction side of the second moving blade 20B, a region with the largest load is formed over the entire leading edge in the radial direction. Specifically, a portion on the leading edge side and on the outer side in the radial direction includes a locally large load portion.

[0032] As described above, the suction-side pressure distribution of the second blade 20B is a leading-edge load, with the load concentrated at the leading edge. On the other hand, the suction-side pressure distribution of the first blade 20A is a balanced load, with the load more distributed in the axis-O direction than the suction-side pressure distribution of the second blade 20B, and the load on the inner side in the radial direction is smaller. <Außenumfangsring>

[0033] As in Fig. 2 and Fig. As illustrated in FIG. 3, the outer peripheral ring 30 is a member constituting an outer peripheral portion of the first propeller 10A and the second propeller 10B and having an annular shape around the axis O. The outer peripheral ring 30 of the first propeller 10A establishes a circumferential connection between the plurality of first moving blades 20A arranged in the circumferential direction. The outer peripheral ring 30 of the second propeller 10B establishes a circumferential connection between the plurality of second moving blades 20B arranged in the circumferential direction. The dimension of the outer peripheral ring 30 of the first propeller 10A in the axis O direction is larger than the dimension of the first moving blade 20A in the axis O direction. The dimension of the outer peripheral ring 30 of the second propeller 10B in the axis-O direction is larger than the dimension of the second blade 20B in the axis-O direction.

[0034] The outer peripheral ring 30 of the first propeller 10A includes an inner peripheral flow path surface 31, a cylindrical fixing surface 32, a holding portion 34, and a downstream end surface 35. The outer peripheral ring 30 of the second propeller 10B includes an inner peripheral flow path surface 31, a tapered fixing surface 33, a holding portion 34, and a downstream end surface 35.

[0035] The inner peripheral flow path surface 31 is a surface forming the inner surface of each outer peripheral ring 30. The inner peripheral flow path surface 31 of the outer peripheral ring 30 of the first propeller 10A is integrally connected to end portions of the plurality of first blades 20A arranged on the outer side in the radial direction in the circumferential direction. The inner peripheral flow path surface 31 of the outer peripheral ring 30 of the second propeller 10B is integrally connected to end portions of the four second blades 20B arranged on the outer side in the radial direction in the circumferential direction.

[0036] The cylindrical fixing surface 32 is a surface that forms the outer surface of the outer peripheral ring 30 of the first propeller 10A. The cylindrical fixing surface 32 forms a cylindrical shape around the axis O and extends in the axis-O direction. The cylindrical fixing surface 32 is parallel to the axis O.

[0037] The tapered fixing surface 33 is a surface forming the outer surface of the outer peripheral ring 30 of the second propeller 10B. The tapered fixing surface 33 forms a conical shape with a diameter that decreases toward the downstream side. The tapered fixing surface 33 has a uniform taper angle and thus extends in the axis O direction at a uniform inclination angle relative to the axis O. With such a tapered fixing surface 33, the thickness of the outer peripheral ring 30 of the second propeller 10B is reduced in the radial direction toward the downstream side.

[0038] The holding portion 34 projects outward in the radial direction from each of the end portion of the cylindrical fixing surface 32 on the upstream side and the end portion of the tapered fixing surface 33 on the upstream side in the respective outer peripheral ring 30 and extends over the entire circumferential direction. <lagerabschnitte>

[0039] The bearing portions 40 support the first propeller 10A and the second propeller 10B so as to be rotatable relative to the shaft portion 3. The bearing portions 40 are provided in the respective receiving grooves 5 and rotatably support the inner circumferential rings 11 of the first propeller 10A and the second propeller 10B. The bearing portions 40 each include a radial bearing 41, an upstream side thrust bearing 42, and a downstream side thrust bearing 43.

[0040] The radial bearing 41 is provided on the groove bottom surface 5a of the receiving groove 5 along the entire circumferential direction. In the present embodiment, a journal bearing is used as the radial bearing 41. The outer diameter of the journal bearing is smaller than the inner diameter of the inner peripheral ring 11. Thus, a clearance is formed between the journal bearing and the inner peripheral ring 11 along the entire circumferential direction.

[0041] The upstream side thrust bearing 42 is provided on the upstream groove surface 5b of the receiving groove 5 throughout the entire circumferential direction. The upstream side thrust bearing 42 faces the upstream end surface 13 of the inner peripheral ring 11 via the clearance in the axis O direction.

[0042] The downstream side thrust bearing 43 is provided on the downstream groove surface 5c of the receiving groove 5 throughout the entire circumferential direction. The downstream side thrust bearing 43 faces the downstream end surface 35 of the inner peripheral ring 11 in the axis-O direction via the clearance.

[0043] Water flowing into the receiving groove 5 is provided between the radial bearing 41, the upstream side thrust bearing 42, and the downstream side thrust bearing 43, and the inner peripheral ring 11. Thus, the radial bearing 41, the upstream side thrust bearing 42, and the downstream side thrust bearing 43 rotatably support the inner peripheral ring 11, forming a water film between the bearings and the inner peripheral ring 11. <mantel>

[0044] The shroud 50 is provided so as to surround the shaft portion 3, the first propeller 10A, and the second propeller 10B from the outer peripheral side. The shroud 50 forms an annular shape around the axis O. The shroud 50 is arranged with a clearance from the outer surface of the shaft portion 3 in the radial direction. Thus, an annular flow path is formed throughout the axis O direction between the shroud 50 and the shaft portion 3. The first moving blades 20A of the first propeller 10A and the second moving blades 20B of the second propeller 10B are arranged in the flow path, and the outer peripheral rings 30 of the first propeller 10A and the second propeller 10B are housed in the shroud 50.

[0045] The surface of the shroud 50 facing the inside in the radial direction is a shroud inner surface 51. The shroud inner surface 51 faces the flow path. The surface of the shroud 50 facing the outside in the radial direction is a shroud outer surface 52.

[0046] The cross-sectional shape of the shroud 50 of the present embodiment, including the axis O, is a blade shape. A connecting portion between end portions of the shroud inner surface 51 and the shroud outer surface 52 on the upstream side is a shroud leading edge 53 extending annularly in the circumferential direction. A connecting portion at end portions of the shroud inner surface 51 and the shroud outer surface 52 on the downstream side is a shroud trailing edge 54 extending annularly in the circumferential direction. The position of the shroud trailing edge 54 in the axis O direction is equal to the position of the rear end of the shaft portion 3 in the axis O direction.

[0047] The shroud 50 has a shape in which the diameter gradually decreases toward the downstream side from the upstream side. In the present embodiment, a converging line in the blade-shaped cross-section of the shroud 50, whose distances from the shroud inner surface 51 and the shroud outer surface 52 are equal, gradually inclines radially inward from the upstream side to the downstream side. Thus, the shroud trailing edge 54 is located radially inward than the shroud leading edge 53.

[0048] The shroud outer surface 52 has a diameter that first increases toward the downstream side in a section around the shroud leading edge 53 and then decreases smoothly toward the downstream side. The shroud outer surface 52 forms a convex curved shape that protrudes toward the outside in the radial direction.

[0049] The shell inner surface 51 has a diameter that decreases on the inner side in the radial direction toward the downstream side throughout the axis-O direction. The shell inner surface 51 forms a convex curved shape that protrudes inward in the radial direction. The annular flow path formed between the shell inner surface 51 and the shell outer surface 3a of the shaft portion 3 is narrowed on the inner side in the radial direction toward the downstream side. Thus, the flow path cross-sectional area of ​​the flow path decreases toward the downstream side.

[0050] The diameter of the shroud inner surface 51 does not have to decrease over the entire section from the shroud leading edge 53 to the shroud trailing edge 54. It is sufficient if the diameter decreases from the shroud leading edge 53 to at least the position of the trailing edge of the second rotor blade 20B of the second propeller 10B in the axis-O direction.

[0051] Thus, the flow path cross-sectional area of ​​the flow path formed by the shroud inner surface 51 and the shaft outer surface 3a need not have a diameter that gradually decreases in the axis-O direction over the entirety of the shroud 50. It is sufficient if the diameter gradually decreases from the shroud leading edge 53 to at least the position of the trailing edge of the second rotor blade 20B of the second propeller 10B in the axis-O direction.

[0052] A first cavity 50A and a second cavity 50B, which are recessed in the radial direction from the shell inner surface 51 to the outer side, are formed in the shell 50. The first cavity 50A is formed in a portion on the upstream side in the shell 50, while the second cavity 50B is formed in a portion on the downstream side in the shell 50. Thus, the second cavity 50B is formed further downstream than the first cavity 50A.

[0053] The outer peripheral ring 30 of the first propeller 10A is housed in the first cavity 50A. The outer peripheral ring 30 of the second propeller 10B is housed in the second cavity 50B. The inner peripheral flow path surface 31 of each outer peripheral ring 30 extends continuously with the shroud inner surface 51 in the axis-O direction. In other words, the inner peripheral flow path surface 31 extends to form part of the convex curved surface of the shroud inner surface 51.

[0054] On a surface in the first cavity 50A facing the inner side in the radial direction, a cylindrical fixing recess portion 56 having a lower portion and forming a cylindrical shape around the axis O is formed. The cylindrical fixing recess portion 56 is formed at a position in the outer peripheral ring 30 of the first propeller 10A corresponding to the cylindrical fixing surface 32 in the axis O direction.

[0055] On a surface in the second cavity 50B facing the inner side in the radial direction, a tapered fixing recess portion 57 is formed with a lower portion and a diameter that decreases toward the downstream side at a uniform taper angle. The tapered fixing recess portion 57 is formed at a position in the outer peripheral ring 30 of the second propeller 10B that corresponds to the tapered fixing surface 33 in the axis-O direction.

[0056] The shell 50 of the present embodiment is formed by coupling a plurality of segments divided in the axis O direction. Specifically, the shell 50 includes, as segments, an upstream segment 61, an intermediate segment 62, and a downstream segment 63.

[0057] The upstream segment 61 forms a section on the upstream side including the shroud leading edge 53.

[0058] The intermediate segment 62 forms a portion continuous to the downstream side of the upstream segment 61 of the shell 50. The first cavity 50A is defined and formed by the intermediate segment 62, which closes a largely notched part of the upstream segment 61 on the inside in the radial direction and on the downstream side from the downstream side.

[0059] The downstream segment 63 forms a portion continuous to the downstream side of the intermediate segment 62 and forms a portion enclosing the shroud trailing edge 54. The second cavity 50B is defined and formed by an intermediate segment 62, which closes a substantially notched portion of the downstream segment 63 on the radially inner side and on the upstream side from the upstream side. <kopplungsabschnitt>

[0060] As in Fig. 1, the coupling portions 70 are provided to protrude from the outer shell surface 52 of the shell 50. The coupling portions 70 couple the plurality of segments of the shell 50 together.

[0061] As detailed in Fig. 5, the coupling portions 70 each include an upstream projecting portion 71, an intermediate projecting portion 72, a downstream projecting portion 73, a coupling bolt 74, and a filling portion 75.

[0062] The upstream protruding portion 71 is integrally provided on the upstream segment 61 of the shell 50 and protrudes from the outer surface of the upstream segment 61. A bolt fixing hole 71a is formed in the upstream protruding portion 71 as a recess from the downstream side to the upstream side.

[0063] The intermediate protruding portion 72 is integrally provided on the intermediate segment 62 of the shell 50 and protrudes from the outer surface of the intermediate segment 62. A bolt through-hole 72a is formed through the intermediate protruding portion 72 in the axis-O direction.

[0064] The downstream protruding portion 73 is integrally provided on the downstream segment 63 of the shell 50 and protrudes from the outer surface of the downstream segment 63. A bolt recess portion 73a is formed in the downstream protruding portion 73 as a recess from the downstream side to the upstream side. A bolt insertion hole 73b is formed in the lower portion of the bolt recess portion 73a, penetrating the lower portion and the surface of the downstream protruding portion 73 facing the upstream side.

[0065] The coupling bolt 74 couples the upstream protruding portion 71, the intermediate protruding portion 72, and the downstream protruding portion 73 together. When the upstream segment 61, the intermediate segment 62, and the downstream segment 63 are coupled together by the coupling portion 70, the upstream protruding portion 71, the intermediate protruding portion 72, and the downstream protruding portion 73 are arranged in this order from the upstream side to the downstream side to sequentially contact each other. In this state, the bolt insertion hole 73b, the bolt through hole 72a, and the bolt fixing hole 71a communicate with each other in the axis O direction. The coupling bolt 74 is inserted and fixed to the bolt insertion hole 73b, the bolt through hole 72a and the bolt fixing hole 71a in communication with each other via the bolt recess portion 73a.As a result, the upstream protruding portion 71, the intermediate protruding portion 72, and the downstream protruding portion 73 are integrally coupled to each other, and the upstream segment 61, the intermediate segment 62, and the downstream segment 63, which are respectively integrated with the upstream protruding portion 71, the intermediate protruding portion 72, and the downstream protruding portion 73, are integrally coupled to each other in the axis-O direction.

[0066] The filling portion 75 is provided to fill the bolt recess portion 73a. The filling portion 75 is, for example, cured resin. The filling portion 75 is formed by pouring resin in a liquid form into the bolt recess portion 73a after the coupling bolt 74 is fastened and allowing the resin to harden. A part of the filling portion 75 forms the outer surface of the coupling portion 70.

[0067] Now, the outer surface shape of the coupling portion 70 as described above will be described with reference to Fig. 5 and Fig. 6. The outer surface shape of the coupling portion 70 is formed by the upstream protruding portion 71, the intermediate protruding portion 72, and the downstream protruding portion 73, as well as the surface of the filling portion 75 exposed from the bolt recess portion 73a. The coupling portion 70 as a whole forms a convex curved shape protruding from the shell outer surface 52. The coupling portion 70 forms a convex curved shape with a longitudinal direction consistent with the axis O direction.

[0068] Furthermore, as in Fig. As illustrated in FIG. 6, the coupling portion 70 of the present embodiment has a blade-shaped cross-sectional shape along the shroud outer surface 52, with the upstream side corresponding to the leading edge and the downstream side corresponding to the trailing edge. The leading edge of the coupling portion 70 is a projecting portion of the leading edge 70a. The trailing edge of the coupling portion 70 is a projecting portion of the trailing edge 70b. Specifically, the coupling portion 70 has a shape obtained by stacking blade shapes in the normal direction with similar shapes and sizes that gradually decrease as they go further in the normal direction of the shroud outer surface 52. <streben>

[0069] As in Fig. 1 and Fig. As illustrated in Figure 2, the struts 78 support the casing 50 with respect to the shaft portion 3 by coupling the casing 50 and the shaft portion 3 together. A plurality of the struts 78 are provided at a distance in the circumferential direction and extend in the axis-O direction. The downstream side end portion of each strut 78 is fixed to the casing 50. The upstream side end portion of the strut 78 is fixed to the shaft outer surface 3a of the shaft portion 3.

[0070] The cross-sectional shape of the strut 78 perpendicular to the axis O is a flat rectangular shape, the longitudinal direction of which coincides with the radial direction and the shorter direction of which coincides with the circumferential direction. Thus, the rotation of the thrust of the underwater vehicle 1 is suppressed. <Rohrförmiger Motor>

[0071] As in Fig. 2 and Fig. 3, the tubular motor 80 is housed in the first cavity 50A of the casing 50. The tubular motor 80 rotatably drives the first propeller 10A. The tubular motor 80 includes a tubular stator 81 and a tubular rotor 82.

[0072] The tubular stator 81 forms a tubular shape around the axis O extending in the axis-O direction. The inner surface and the outer surface of the tubular stator 81 are parallel to the axis O. The outer surface of the tubular stator 81 is attached to the cylindrical fixing recess portion 56 in the first cavity 50A of the shell 50. Thus, the tubular motor 80 is integrally fixed to the shell 50.

[0073] The tubular rotor 82 forms a tubular shape around the axis O extending in the axis O direction. The inner surface and the outer surface of the tubular rotor 82 are parallel to the axis O. The outer diameter of the tubular rotor 82 is set smaller than the inner diameter of the tubular stator 81. The dimension of the tubular rotor 82 in the axis O is the same as that of the tubular stator 81. The tubular rotor 82 is integrally fixed to the cylindrical fixing surface 32 of the first propeller 10A from the outer peripheral side. The outer surface of the tubular rotor 82 faces the inner surface of the tubular stator 81 throughout the entire circumferential direction and the entire axis O direction. A clearance is formed between the outer surface of the tubular rotor 82 and the inner surface of the tubular stator 81 over the entire circumferential direction and the entire axis-O direction.

[0074] The upstream side end surface of the tubular rotor 82 is in contact with the holding portion 34 in the outer peripheral ring 30 of the first propeller 10A from the downstream side.

[0075] A first retaining plate 83 is in contact with the downstream side end surface of the tubular rotor 82. The first retaining plate 83 is provided entirely between the downstream side end surface of the tubular rotor 82 and the downstream end surface 35 of the outer peripheral ring 30 of the first propeller 10A. By fixing the first retaining plate 83 to the outer peripheral ring 30 using an unillustrated bolt, the tubular rotor 82 is fixed from the downstream side by means of the first retaining plate 83.

[0076] In the tubular motor 80, when the tubular stator 81 is energized, a rotating magnetic field is generated, causing the tubular rotor 82 to rotate about the axis O. <Konischer Motor>

[0077] As in Fig. 2 and Fig. 3, the conical motor 90 is housed in the second cavity 50B of the shroud 50. The conical motor 90 drives the second propeller 10B. The conical motor 90 includes a conical stator 100 and a conical rotor 130. <Konischer Stator>

[0078] As in Fig. 2 and Fig. 3, the conical stator 100 is mounted in the second cavity 50B of the shell 50. As shown in Fig. 7 and Fig. 8, the conical stator 100 includes a stator core 101 and coils 110. <statorkern>

[0079] The stator core 101 includes a back yoke 104 forming an annular shape around the axis O and teeth 106 projecting from the inner surface of the back yoke 104.

[0080] The back yoke 104 has an inner surface and an outer surface that form a tapered shape that inclines inward toward the downstream side in the radial direction. Thus, the back yoke 104 as a whole has a shape with a diameter that decreases toward the downstream side. The thickness of the back yoke 104 in the radial direction is constant throughout the axis O direction and the circumferential direction. The outer surface of the back yoke 104 is a stator outer surface 102. The stator outer surface 102 is attached and fixed to the tapered fixing recess portion 57 in the second cavity 50B of the shell 50, as shown in Fig. 3. Thus, the conical stator 100 is integrally fixed in the second cavity 50B of the shell 50. The cone angle of the stator outer surface 102, which is the outer surface of the back yoke 104, and the cone angle of the lower surface of the tapered fixing recess portion 57 are set equal. <Zähne>

[0081] As in Fig. As illustrated in Fig. 7, four of the teeth 106 are provided at a circumferential pitch on the inner peripheral side of the back yoke 104. The teeth 106 include a tooth body 107 connected to the back yoke 104 and extending in the radial direction; and a distal end portion 108, which is a portion provided at an end portion of the tooth body 107 on the inner side in the radial direction and widening to both sides in the circumferential direction from the tooth body 107.

[0082] As in Fig. As illustrated in Figure 8, the protrusion heights of the teeth 106 from the inner surface of the back yoke 104 are constant in the axis-O direction. Thus, a stator inner surface 103, which is an end portion of the teeth 106 on the inner side in the radial direction, is inclined radially inward toward the downstream side. In other words, the stator within the surface 103 has a diameter that decreases toward the downstream side. A clearance between adjacent teeth 106 serves as a slot that accommodates the coil 110.

[0083] The teeth 106 are configured to have a thickness in the circumferential direction that decreases toward the downstream side. Thus, the plurality of teeth 106 can be arranged without affecting the inside of the back yoke 104 with a diameter that decreases toward the downstream side. <spulen>

[0084] A plurality of coils 110 are provided to surround the respective tooth bodies 107 extending in the radial direction. Each coil 110 is formed by stacking a plurality of coil layers 120 arranged in Fig. 9 in the radial direction. With each coil layer 120 surrounding the outer surface of the tooth body 107, the coil as a whole is provided on the outer surface of the tooth body 107.

[0085] Each coil layer 120 is formed by a rectangular copper wire. The cross-sectional shape of the rectangular copper wire is a shape that is squeezed in an extending direction of the tooth body 107, and thus is a flat shape whose shorter direction coincides with the radial direction.

[0086] The coil layer 120 has a rectangular annular shape surrounding the tooth body 107, as shown in Fig. 9, according to the cross-sectional shape of the tooth body 107 perpendicular to the radial direction. A portion of the coil layer 120 extending in the circumferential direction on the upstream side is an upstream part 121 that comes into contact with the tooth body 107 from the upstream side.

[0087] A portion of the coil layer 120 extending in the circumferential direction on the downstream side is a downstream part 122 that contacts the tooth body 107 from the downstream side. The circumferential dimension of the downstream part 122 is shorter than the circumferential dimension of the upstream part 121.

[0088] A pair of portions of the coil layer 120 extending circumferentially in the axis-O direction on both sides of the teeth 106 are each a side part 123. The two side parts 123 are in contact with the teeth 106 from both sides in the circumferential direction and extend toward each other toward the downstream side.

[0089] Each coil 110 forms a spiral winding around the tooth body 107, with the plurality of coil layers 120 being electrically connected to one another and stacked in the radial direction.

[0090] As in Fig. 8, portions of the coil 110 provided around the teeth 106 at both ends in the axis-O direction, that is, portions projecting from the teeth 106 on the upstream side and the downstream side, respectively, are spiral ends 111. A portion of the coil 110 including the coil ends 111, that is, a portion in contact with the teeth 106 from both sides in the circumferential direction, is a coil main portion 112.

[0091] In the present embodiment, as shown in Fig. 8 illustrates the portions of the coil 110 constituting the coil main portion 112 and the coil end 111 on the downstream side so as to be inclined radially inward toward the downstream side. Thus, the side portions 123 and the downstream portion 122 of each coil layer 120 are arranged so as to be inclined radially inward toward the downstream side.

[0092] In contrast, the portion of the coil 110 constituting the coil end 111 on the upstream side is bent relative to the coil main portion 112 to extend parallel to the axis O direction. In other words, the upstream part 121 of each coil layer 120 is bent relative to the pair of side parts 123 of the coil layer 120 to extend parallel to the axis O.

[0093] In the present embodiment, the axis O direction positions of the downstream side end portions of the coil layers 120 are the same among the coil layers 120. The axis O direction positions of the upstream side end portions of the coil layers 120 are the same among all the coil layers 120. The end portions of the coil ends 111 in the axis O direction are arranged such that their axis O direction positions are the same among all the coil layers 120. <Konischer Rotor>

[0094] As in Fig. 2 and Fig. 3 and in detail in Fig. 10, the conical rotor 130 is fixed to the outer peripheral side of the outer peripheral ring 30 of the second propeller 10B. As shown in Fig. 7 and Fig. 8, the conical rotor 130 includes a rotor core 131 and permanent magnets 140.

[0095] The rotor core 131 has an annular shape around the axis O and extends in the axis O direction. The inner surface of the rotor core 131 is a rotor inner surface 132. The outer surface of the rotor core 131 is a rotor outer surface 133. The rotor core 131 has the rotor inner surface 132, and the rotor outer surface 133 forms a tapered shape that slopes inward in the radial direction toward the downstream side. Thus, the rotor core 131 as a whole has a shape with a diameter that decreases toward the downstream side. The outer shape of the rotor core 131 is the outer shape of the conical rotor 130.

[0096] The rotor inner surface 132 is attached to the tapered fixing surface 33 of the outer peripheral ring 30 of the second propeller 10B from the outer peripheral side. Thus, the rotor core 131 is integrally fixed to the outer peripheral ring 30 of the second propeller 10B. The taper angle of the rotor inner surface 132 and the taper angle of the tapered fixing surface 33 are the same.

[0097] An insertion hole 134 through which the upstream side end surface and the downstream side end surface of the rotor core 131 communicate with each other is formed in the rotor core 131. A plurality of the insertion holes 134 are provided at a distance in the circumferential direction. The rotor inner surface 132 and the rotor outer surface 133 extend in parallel. In other words, the insertion hole 134 extends inclined inward toward the downstream side in the radial direction. The dimension of the insertion hole 134 in the radial direction is the same across the axis O direction. The insertion hole 134 is formed to have a distance between its circumferentially facing side surfaces that decreases toward the downstream side. < Permanent magnets>

[0098] As in Fig. 7 and Fig. As illustrated in Figure 8, a plurality of permanent magnets 140 are provided at a distance from the rotor core 131 in the circumferential direction. Each permanent magnet 140 is inserted into a corresponding one of the insertion holes 134 of the rotor core 131.

[0099] As in Fig. As illustrated in FIG. 11, the permanent magnet 140 has a flat plate shape. In a state where the permanent magnet 140 is inserted into the insertion hole 134 of the rotor core 131, it has a surface facing the outside in the radial direction, which is a magnet outer surface 141, and a surface facing the inside in the radial direction, which is a magnet inner surface 142. The magnet outer surface 141 and the magnet inner surface 142 are parallel to each other and each extend inclined inward toward the downstream side in the radial direction. The magnet outer surface 141 and the magnet inner surface 142 form a trapezoidal shape with a circumferential dimension that decreases toward the downstream side as viewed in the radial direction.

[0100] A pair of surfaces of the permanent magnet 140 facing the circumferential direction are magnet side surfaces 143. The pair of magnet side surfaces 143 radially connect the magnet outer surface 141 and the magnet inner surface 142 across the axis O direction. The magnet side surfaces 143 extend radially toward the downstream side, like the magnet outer surface 141 and the magnet inner surface 142.

[0101] The surface of the permanent magnet 140 facing the upstream side is an upstream magnet surface 144. The upstream magnet surface 144 has a planar shape perpendicular to the axis O. The upstream magnet surface 144 is connected to the upstream side end portions of the magnet outer surface 141, the magnet inner surface 142, and the pair of magnet side surfaces 143.

[0102] The downstream side surface of the permanent magnet 140 is a downstream magnet surface 145. The downstream magnet surface 145 has a planar shape perpendicular to the axis O and is parallel to the upstream magnet surface 144. The downstream magnet surface 145 is connected to the downstream side end portions of the magnet outer surface 141, the magnet inner surface 142, and the pair of magnet side surfaces 143.

[0103] The magnetization direction of the permanent magnet 140 is a direction inclined to the downstream side, in the radial direction to the outside, as shown by the arrows in Fig. 11. Specifically, the magnetization direction is a direction perpendicular to the magnet inner surface 142 and the magnet outer surface 141, and is a direction from the magnet inner surface 142 to the magnet outer surface 141. The inclination angles of the magnet inner surface 142 and the magnet outer surface 141 relative to the axis O are the same as the cone angle of the rotor outer surface 133. Thus, the magnetization direction of the permanent magnet 140 is a direction perpendicular to the rotor outer surface. The permanent magnet 140 is uniformly magnetized in a direction along the magnet inner surface 142 and the magnet outer surface 141.

[0104] In the conical motor 90, the conical rotor 130 is driven to rotate about the axis O by the rotating magnetic field generated when the coils 110 of the conical stator 100 are energized. The rotation direction of the conical motor 90 is opposite to the rotation direction of the tubular motor 80. Thus, the rotation directions of the conical motor 90 and the tubular motor 80 are opposite to each other.

[0105] As in Fig. 10, in the conical rotor 130, the upstream side end portion is in contact with the holding portion 34 from the downstream side while being fixed to the outer peripheral ring 30 of the second propeller 10B.

[0106] The downstream side end portion of the conical rotor 130 is held by a second holding plate 150 from the downstream side.

[0107] The downstream side end portion of the conical rotor 130 and the downstream end surface 35 of the outer peripheral ring 30 each have a flat shape perpendicular to the axis O and are arranged to be flush. The second retaining plate 150 contacts both the downstream side end portion of the conical rotor 130 and the downstream end surface 35 of the outer peripheral ring 30. The second retaining plate 150 has a plate shape extending across the entire circumferential direction, corresponding to the shapes of the downstream side end portion of the conical rotor 130 and the downstream end surface 35 of the outer peripheral ring 30.

[0108] This second retaining plate 150 is fixed to the outer peripheral ring 30 by a retaining bolt 151. The retaining bolt 151 is inserted from the downstream side into a bolt stop hole 150a formed through the second retaining plate 150 in the axis O direction and fixed in the bolt stop hole 150a formed recessed from the downstream end surface 35 of the outer peripheral ring 30.

[0109] As in Fig. 9 in addition to Fig. As illustrated in Fig. 10, a portion of the retaining pin 151 in the circumferential direction is received in a notched portion 135 formed to be recessed from the outer surface of the rotor core 131 in a portion around an opening portion of the pin stop hole 150a. The notched portion 135 is formed in a portion between circumferentially adjacent permanent magnets 140 in the rotor core 131. <wirkungsweise>

[0110] The underwater vehicle 1 with the above-described configuration can be propelled underwater with the thruster 8. Specifically, when the tubular motor 80 in the first cavity 50A of the casing 50 is driven, the first propeller 10A, which is integrally attached to the tubular rotor 82 of the tubular motor 80, rotates about the axis O to one side in the circumferential direction. As a result, the water is pumped to the downstream side by the first rotor blades 20A positioned in the flow path. When the conical motor 90 is driven simultaneously with the driving of the tubular motor 80, the second propeller 10B, which is integrally attached to the conical rotor 130 of the conical motor 90, rotates about the axis O to the other side in the circumferential direction. As a result, the water is pumped to the downstream side by the second rotor blades 20B positioned in the flow path.

[0111] Then, the thrust force toward the upstream side is generated at the first propeller 10A and the second propeller 10B as a reaction force generated by the pumping of water. The thrust force is transmitted from the inner circumferential rings 11 of the first propeller 10A and the second propeller 10B to the shaft portion 3 via the water film and the upstream side thrust bearing 42. Thus, the thrust force acts on the shaft portion 3 and the integral vehicle body 2, thereby propelling the underwater vehicle body 1.

[0112] In the thrust apparatus 8 of the present embodiment, as shown in Fig. 2 and Fig. 3, the diameter of the shroud 50 and the diameter of the shaft portion 3 decrease toward the downstream side. Thus, the flow path formed between the shroud 50 and the shaft portion 3 has a shape that narrows in the radial direction toward the downstream side, which means that the flow path cross-sectional area decreases toward the downstream side. When the water is pumped by the first moving blades 20A and the second moving blades 20B, the flow velocity of the water increases, resulting in the flow of the water narrowing on the radially inner side. In the present embodiment, the flow path has a shape suitable for the flow of the water, whereby the water pumping efficiency can be improved.

[0113] In the present embodiment, the diameter shape of the shell 50 gradually decreases toward the downstream side, thus having a tapered shape such that the diameter becomes smaller toward the downstream side. According to this shape of the shell 50, the conical motor 90 accommodated in the shell 50 also has a tapered shape with a diameter decreasing toward the downstream side. Thus, the conical motor 90 as an outer peripheral drive device can be arranged along the shape of the shell 50. Thus, the shape of the shell 50 does not need to be undesirably larger according to the configuration of the motor, which means that the shell 50 as a whole can have a compact configuration.

[0114] In the present embodiment, since the casing 50 thus has a compact configuration, the resistance when propelling the underwater vehicle 1 in the water is small. Thus, the speed of the underwater vehicle 1 can be increased and the propulsion efficiency can be improved.

[0115] Furthermore, in the present embodiment, the cross-sectional shape of the shroud 50 is a blade shape, with the upstream side being the leading edge and the downstream side being the trailing edge, thereby minimizing the resistance in water. Furthermore, the converging line of the blade shape cross section of the shroud 50 is inclined radially inward toward the downstream side, and the shroud 50 as a whole, which forms the blade shape, has a tapered shape with a diameter decreasing toward the downstream side. Thus, the shape of the shroud 50 conforms to the flow direction of the pumped water, thereby further improving the pumping efficiency.

[0116] In a case where the shape of the motor housed in the shroud 50 does not correspond to the shape of the shroud 50, in order to maintain the blade shape when housing the motor, the curved shapes of the shroud outer surface 52 and the shroud inner surface 51 may need to undesirably bulge to accommodate the motor. In other words, the shape of the shroud 50 may need to be enlarged to accommodate the motor.

[0117] In contrast, in the present invention, the conical motor 90 disposed in the shroud 50 has a tapered shape that conforms to the shape of the shroud 50, thereby eliminating the need to undesirably increase the blade-like shape of the shroud 50 in accordance with the conical motor 90. Thus, the shroud 50 can have a compact shape while maintaining the blade shape. Thus, resistance in water during propulsion can be minimized.

[0118] Furthermore, in the present embodiment, counter-rotating propellers are used, in which the rotation directions of the first propeller 10A on the upstream side and the second propeller 10B on the downstream side are reversed. Thus, the vortex flow generated by the pumping of water by the first propeller 10A can be absorbed by the reverse rotation of the second propeller 10B, thereby reducing the vortex loss at the propeller jet of the second propeller 10B.

[0119] When the water is sucked in, the resistance in water tends to increase due to the pressure interference between the first moving blades 20A of the first propeller 10A, positioned on the upstream side, and the shaft portion 3. In particular, a configuration in which the load is concentrated over the entire leading edge of each moving blade to improve propeller efficiency results in significant resistance in water.

[0120] In contrast, in the present embodiment, as shown in Fig. 4, the load distribution on the suction side of the first blade 20A is a balanced load, the load being distributed in the axis-O direction, with the load on the inner side in the radial direction being small.

[0121] Thus, an increase in fluid resistance due to pressure interference can be minimized.

[0122] On the other hand, the suction side pressure distribution of the second moving blade 20B of the second propeller 10B on the downstream side, which is unlikely to be involved in the pressure interference with the shaft portion 3, is a leading edge load, with the load concentrated at the leading edge, so that the propeller efficiency can be improved.

[0123] As in Fig. As illustrated in Fig. 3, the thrust of the first propeller 10A and the second propeller 10B is transmitted to the shaft portion 3 via the upstream side thrust bearing 42. In other words, the thrust is transmitted as a load to the upstream side thrust bearing 42. When the thrust is large, the load transmitted to the upstream side thrust bearing 42 is also large, which means that the load on the upstream side thrust bearing 42 is large.

[0124] In the present embodiment, when the conical motor 90 is driven, the electromagnetic force acts in the direction (gap direction) in which the conical rotor 130 and the conical stator 100 of the conical motor 90 face. The electromagnetic force is directed toward the outside in the radial direction and toward the downstream side. Thus, the downstream force is applied to the conical rotor 130 as a component of the electromagnetic force in the axis O direction.

[0125] Thus, the force acting on the conical rotor 130 pulls it toward the downstream side. As a result, the load exerted on the upstream side thrust bearing 42 by the second propeller 10B is reduced, thereby reducing the thrust load generated by the upstream side thrust bearing 42.

[0126] Furthermore, in the present embodiment, by decoupling the Fig. 5, the shell 50 may be divided into a plurality of segments (the upstream segment 61, the intermediate segment 62, and the downstream segment 63). Thus, the tubular stator 81 of the tubular motor 80 and the conical stator 100 of the Fig. 3 can be easily mounted in the casing 50.

[0127] As in Fig. 5 and Fig. As illustrated in Fig. 6, the coupling portion 70 has a convex curved shape protruding from the outer surface of the shroud 50, and the cross-sectional shape along the outer surface of the shroud 50 has a blade shape, with the upstream side being the protruding portion of the leading edge 70a and the downstream side being the protruding portion of the trailing edge 70b. Thus, the resistance due to the coupling portion 70 when propelling the underwater vehicle 1 can be suppressed.

[0128] The conical stator 100 of the conical motor 90 of the present embodiment is accommodated in the second cavity 50B, and is fixed only to the second cavity 50B of the downstream side segment between the intermediate segment 62 and the downstream segment 63 defining the second cavity 50B.

[0129] The downstream force, which is a component of the electromagnetic force, acts on the conical rotor 130 as described above, while the upstream force, which is a component of the electromagnetic force, acts on the conical stator 100 paired with the conical rotor 130. Thus, the upstream force also acts on the downstream segment 63 to which the conical stator 100 is integrally attached.

[0130] As a result, the downstream segment 63 is pressed against the intermediate segment 62 by the force. Thus, the downstream segment 63 and the intermediate segment 62 can be more rigidly fixed and integrated with each other, and the fastening force of the coupling portion 70 coupling these bodies can be weakened. Accordingly, a fastening bolt with a smaller diameter can be used for the fastening portion, and the coupling portion 70 can be made compact, thereby further reducing the resistance due to the coupling portion 70 against the water flow.

[0131] The conical stator 100 of the conical motor 90 has a tapered shape that matches the shape of the shell 50. This contributes to the compactness of the shell 50 while providing the function of the stator of the motor.

[0132] As in Fig. 9, the coil layers 120 constituting the respective layers of the coil 110 have a configuration corresponding to the outer surface of the teeth 106, that is, a rectangular annular shape with a pitch in the circumferential direction decreasing toward the downstream side, whereby the coil 110 can be arranged at a high density relative to the teeth 106.

[0133] In addition, as in Fig. 8 illustrates, the coil layers 120 constituting the respective layers of the coil 110 are inclined radially inward toward the downstream side in accordance with the conical shape of the teeth 106. Thus, the coil 110 can be arranged at a high density relative to the stator core 101 of the conical stator 100.

[0134] The positions of the upstream side end portion and the downstream side end portion of the coil ends 111 in the axis-O direction are the same for all the coil layers 120, and the coil 110 can be arranged with a compact size in the axis-O direction at high density.

[0135] If the coil layers 120 formed using rectangular copper wires with the same cross-sectional shape are stacked without matching the positions of the end portions of the coils 110, a gap is formed between the coil layers 120 and the teeth 106 in the axis-O direction. In this case, numerous gaps in the magnetic flux exist, thereby degrading motor efficiency. In the present embodiment, the coil layers 120 can be arranged at a high density with the gap between the coil layers 120 and the teeth 106. Thus, motor efficiency can be improved.

[0136] In addition, the coil 110 as a whole can have a shorter length, whereby the copper loss of the coil 110 can be reduced, so that the efficiency of the motor can be improved.

[0137] In the present embodiment, the upstream end portion of the coil layer 120 constituting each layer of the coil 110 is configured to be bent parallel to the axis O. Thus, the gap between the rectangular copper wire and the teeth 106 at the coil end 111 can be minimized while increasing the density of the layers at the coil end 111.

[0138] The conical rotor 130 of the conical motor 90 has a tapered shape that matches the conical shape of the shell 50. This contributes to the compactness of the shell 50 while providing the function of the motor's rotor.

[0139] Furthermore, in the present embodiment, the magnetization direction of the permanent magnet 140 is perpendicular to the rotor outer surface 133 of the conical rotor 130, rather than simply in the radial direction. In other words, the magnetization direction of the permanent magnets 140 coincides with the direction in which the rotor and stator face. Thus, the contribution of the permanent magnet 140 to the torque can be maximized, thereby improving the torque of the conical motor 90.

[0140] The electromagnetic force toward the outside in the radial direction and the downstream side acts on the rotor core 131 of the conical motor 90. In view of this, in the present embodiment, the rotor core 131 is held by the second holding plate 150 from the downstream side and thus can be prevented from falling to the downstream side.

[0141] The thickness of the downstream end of the outer peripheral ring 30 of the second propeller 10B in the radial direction is small. Thus, it may be difficult to form a bolt hole 36 in a portion of the downstream end of the outer peripheral ring 30. Forming the bolt hole 36 despite this difficulty results in insufficient resistance of the outer peripheral ring 30 and is thus not preferable. On the other hand, in the present embodiment, the notched portion 135, which receives a part of the outer surface of the retaining bolt 151, is formed in the rotor. Thus, the retaining bolt 151 is inserted so as to be inserted into the notched portion 135. Part of the load from the retaining bolt 151 can be absorbed by the notched portion 135.Thus, the holding bolt 151 can be appropriately fixed with respect to the outer peripheral ring 30, whereby the rotor core 131 can be more effectively prevented from falling by the second holding plate 150.

[0142] The movement of the rotor core 131 relative to the outer peripheral ring 30 in the circumferential direction can be restricted by the notched portion 135. Thus, the rotor core 131 can be prevented from undesirably shifting in the circumferential direction, and the rotor core 131 and the outer peripheral ring 30 can be secured to each other more rigidly.

[0143] The notched portion 135 is formed in a portion between the adjacent permanent magnets 140 in the rotor core 131. When the notched portion 135 is formed in a portion on the outer side in the radial direction of the permanent magnet 140, the passage of a magnetic flux through the rotor core 131 is obstructed, resulting in an increase in magnetic resistance. With the notched portion 135 formed between the adjacent permanent magnets 140 as in the present embodiment, the hollowing of the magnetic path of the rotor core 131 can be minimized, thereby suppressing the increase in magnetic resistance. <Weitere Ausführungsformen>

[0144] The embodiments of the present invention have been described above, but the present invention is not limited thereto and can be modified as needed within a range not deviating from the technical spirit of the invention.

[0145] While in the embodiment, an example is described in which only the motor that drives the second propeller 10B of the two propellers, the first propeller 10A and the second propeller 10B, is the conical motor 90, a motor that drives both the first propeller 10A and the second propeller 10B may be a motor with a conical shape. Alternatively, the motor that drives the first propeller 10A may have a conical shape, while the motor that drives the second propeller 10B may have a tubular shape. That is, it is sufficient if the motor that drives at least one of the first propeller 10A and the second propeller 10B is a conical-shaped motor.

[0146] Furthermore, three or more propellers may be provided, an outer peripheral drive motor may be provided in correspondence to these propellers, and at least one of these motors may be a conical-shaped motor.

[0147] As the thruster 8, only a propeller and a motor driving the propeller may be provided, and this motor may have a conical shape.

[0148] In both cases, the motor can be arranged to conform to the shape of the shell 50 with the decreasing diameter, and thus the shell 50 can be made compact.

[0149] In the embodiment, an example is described in which the cross-sectional shape of the shroud 50 has a blade shape. However, the blade shape should not be interpreted in a limiting sense. The cross-sectional shape of the shroud 50 is preferably a streamlined shape, but may have other shapes such as a rectangular shape. In this case, too, in the shroud 50 with the diameter decreasing toward the downstream side, a flow path with a flow path cross-sectional area decreasing toward the downstream side is defined and formed.

[0150] In the embodiment, an example is described in which the shroud 50 is divided into three segments according to the number of motors. However, the present invention is not limited to this, and a configuration in which the shroud 50 is divided in the axis-O direction by the outer peripheral ring 30 of the propeller and the motor interposed therebetween may be adopted. Furthermore, a configuration in which the shroud 50 is divided into four or more segments in the axis-O direction, with the outer peripheral ring 30 of the propeller and the motor interposed between adjacent ones of the segments, may be adopted.

[0151] In the embodiment, a configuration is described in which the conical stator 100 of the conical motor 90 is fixed only to the downstream segment 63, outside the intermediate segment 62 and the downstream segment 63. However, the present invention is not limited to this. The conical stator 100 need not be fixed only to the downstream segment 63, but may also be fixed to the intermediate segment 62. Thus, the stator of the motor can be fixed to both adjacent segments. More preferably, the conical stator 100 may be fixed only to the downstream side segment of the adjacent segments. With this configuration, as in the embodiment, the adjacent segments can be fixed more rigidly in the axis O direction, and the coupling portion 70 can be made compact.

[0152] In the embodiment, an example is described in which, out of the coil ends 111 on the upstream side and the downstream side, only the coil end 111 on the upstream side is bent parallel to the axis O. However, the present invention is not limited to this, and as a first development, for example, both coil ends 111 on the upstream side and the downstream side may have a shape bent parallel to the axis O, as shown in Fig. 12. In addition, a second training course, as in Fig. 13, a shape in which only the coil end 111 on the downstream side is bent in the axis O direction may be used. Even with these configurations, effects similar to those in the embodiment can be obtained.

[0153] Furthermore, in the embodiment, an example in which the fluid machine according to the present invention is applied to the thruster 8 of the underwater vehicle 1 is described. However, the present invention is not limited to this, and for example, the fluid machine can be applied to the thruster 8 of a ship or the like that travels on water.

[0154] The fluid machine according to the invention is not limited to the thruster 8 and can be applied to other underwater fluid machines, such as a pump. Furthermore, the present invention is not limited to a fluid machine that pumps water and can be applied to a fluid machine that pumps other types of fluids, such as oil. Notes

[0155] The thruster (fluid machine) 8 and the underwater vehicle 1 described in each of the embodiments are configured, for example, as follows.

[0156] (1) A fluid machine according to a first aspect includes: a shaft portion 3 extending in an axis-O direction; a shell 50 provided to surround the shaft portion 3 and having a diameter decreasing from an upstream side on one side in the axis-O direction to a downstream side on another side in the axis-O direction, a flow path formed between the shell 50 and the shaft portion 3 and having a flow path cross-sectional area decreasing toward the downstream side; a propeller rotatably provided around the axis O between the shaft portion 3 and the shell 50 and configured to pump a fluid from the upstream side toward the downstream side;and a motor provided in correspondence with the propeller, the motor comprising a rotor having an annular shape and fixed to an outer peripheral portion of the propeller and housed in the casing 50, and a stator having an annular shape, surrounding the rotor, and fixed in the casing 50, the motor being a conical motor 90 in which diameters of the rotor and the stator decrease from the upstream side to the downstream side;

[0157] With the configuration described above, the shell 50 has the diameter decreasing toward the downstream side, and the flow path cross-sectional area of ​​the flow path on the inside decreases toward the downstream side, whereby the pumping efficiency of a fluid can be improved.

[0158] Furthermore, the above-described configuration uses the conical motor 90 with the rotor and stator of decreasing diameters, since the diameter of the shell 50 decreases toward the downstream side. Thus, the shape of the shell 50 does not need to be larger to match the configuration of the motors, thereby achieving a compact configuration.

[0159] (2) A fluid machine according to a second aspect is the fluid machine according to (1), in which the shroud 50 has a cross-sectional shape perpendicular to the axis O with a blade shape, an end portion on the upstream side corresponding to a leading edge and an end portion on the downstream side corresponding to a trailing edge.

[0160] The cross-sectional shape of the shroud 50 has a vane shape, which minimizes the resistance due to water flow when the fluid machine is located underwater. A shape that adapts to the flow direction of the fluid pumped by the propeller is achieved, thereby further improving pumping efficiency.

[0161] In order to maintain the blade shape while accommodating the motor inside, the shape of the shroud 50 may need to be enlarged more than necessary to match the shape of the motor. Given this, in the present aspect, the conical motor conforms to the shape of the shroud 50, thereby reducing the size of the shroud 50.

[0162] (3) A fluid machine according to a third aspect is the fluid machine according to (1) or (2), in which two of the propellers are provided in the axis-O direction, rotation directions of the two propellers are opposite to each other, the motor is provided for each of the two propellers, and at least one of two of the motors is the conical motor 90.

[0163] By using counter-rotating propellers in which the rotation directions of the first propeller 10A on the upstream side and the second propeller 10B on the downstream side are inverted, the vortex flow generated by the first propeller 10A can be captured by the second propeller 10B. Thus, the vortex loss at the propeller's downstream side can be reduced.

[0164] In addition, even if two motors are provided, at least one of them is the conical motor 90, and thus the enlargement of the shell 50 can be prevented.

[0165] (4) A fluid machine according to a fourth aspect is the fluid machine according to (3), wherein each of the propellers includes a plurality of circumferentially arranged moving blades, wherein a suction-side pressure distribution of the moving blade of the propeller on the downstream side is a leading edge load with a load concentrated at a leading edge, and a suction-side pressure distribution of the moving blade of the propeller on the upstream side is a balanced load, the load being more distributed in the axis-O direction than the suction-side pressure distribution of the moving blade on the downstream side, the load being smaller on an inner side in the radial direction.

[0166] Here, the fluid resistance between the upstream-side moving blade and the shaft portion 3 tends to increase due to pressure interference during water intake. In particular, a configuration in which the load is concentrated over the entire leading edge of the moving blade to improve propeller efficiency makes this tendency significant. In the present aspect, the suction-side pressure distribution of the upstream-side moving blade is a balanced load, and thus, an increase in fluid resistance due to pressure interference can be minimized.

[0167] On the other hand, the suction side pressure distribution of the blade on the downstream side is of a leading edge load type, in which the load is concentrated at the leading edge, so that the propeller efficiency can be improved.

[0168] (5) A fluid machine according to a fifth aspect is the fluid machine according to any one of (1) to (4), in which the propeller includes an inner peripheral ring 11 attached to an outer peripheral side of the shaft portion 3 via a clearance, and the fluid machine further includes: a thrust bearing fixed to the shaft portion 3 and facing the upstream side of the inner peripheral ring 11 over an entire circumferential direction; and a stay 78 supporting the shell 50 relative to the shaft portion 3.

[0169] When the propeller rotates, a load is applied to the propeller itself toward the upstream side as a reaction force generated by pumping a fluid. The load of the propeller is supported by the thrust bearing. When driving the conical motor, the electromagnetic force acts toward the outside in the radial direction and the downstream side acts on the conical rotor 130. Thus, the force acts on the conical rotor 130 to pull it toward the downstream side. This reduces the load applied to the thrust bearing from the propeller, thereby reducing the thrust load.

[0170] (6) A fluid machine according to a sixth aspect is the fluid machine according to any one of (1) to (5), in which the shell 50 includes a plurality of segments of the shell 50 divided into a plurality of parts in the axis-O direction, and the fluid machine further includes a coupling portion 70 configured to couple the plurality of segments in the axis-O direction.

[0171] By decoupling the coupling section 70, the casing 50 can be separated into a plurality of segments. This allows the rotor and stator of the motors to be mounted in the casing 50.

[0172] (7) A fluid machine according to a seventh aspect is the fluid machine according to (6), in which the coupling portion 70 has a convex curved shape protruding from an outer surface of the shroud 50, and a cross-sectional shape along the outer surface of the shroud 50 has a blade shape, the upstream side being a leading edge and the downstream side being a trailing edge.

[0173] Thus, resistance due to the coupling portion 70 can be suppressed when water flows on the outer surface of the shell 50.

[0174] (8) A fluid machine according to an eighth aspect is the fluid machine according to (1) to (7), in which the stator includes: a stator core 101 having a back yoke 104 forming an annular shape around the axis O and having a diameter that decreases toward the downstream side, and a plurality of teeth 106 that project from an inner surface of the back yoke 104 toward the inside in the radial direction, extend in a circumferential direction over the entire axis O direction, and have a thickness in the circumferential direction that decreases with a decreasing diameter toward the downstream side; and a plurality of coils 110 provided so as to surround the individual teeth 106.

[0175] As a result, the configuration of the stator may have a conical shape corresponding to the shape of the shell 50 with the decreasing diameter.

[0176] (9) A fluid machine according to a ninth aspect is the fluid machine according to (8), wherein each of the coils 110 comprises a rectangular copper wire having a flat shape with a plurality of layers stacked in the radial direction around the teeth 106, and each layer of the coil 110 has a rectangular shape with a pitch in the circumferential direction decreasing toward the downstream side as viewed in the radial direction.

[0177] By configuring the shape of the respective layers of the coil 110 corresponding to the teeth 106, the coil 110 can be arranged at a high density relative to the teeth 106.

[0178] (10) A fluid machine according to a tenth aspect is the fluid machine according to (9), in which each layer of the spool 110 is inclined radially inward toward the downstream side. As a result, the spool 110 can be efficiently arranged with respect to the teeth 106 extending radially inward toward the upstream side.

[0179] (11) A fluid machine according to an eleventh aspect is the fluid machine according to (10), wherein the axis-O direction positions of end portions of the coil ends 111 of each coil 110 in the axis direction in each layer correspond to each other.

[0180] With this configuration, the coil 110 can be arranged at a high density with a compact size in the axis-O direction. Since the coil 110 as a whole has a shorter length, the efficiency of the motor can be improved.

[0181] (12) A fluid machine according to a twelfth aspect is the fluid machine according to (11), in which a portion of each layer of the coil 110 constituting the coil end 111 is bent to be parallel to the axis O.

[0182] Thus, the gap between the rectangular copper wire and the teeth 106 at the coil end 111 can be minimized while increasing the density of the layers at the coil end 111.

[0183] (13) A fluid machine according to a thirteenth aspect is the fluid machine according to any one of (1) to (12), wherein the rotor includes: a rotor core 131 forming a tubular shape around the axis O and having a diameter that decreases toward the downstream side; and a plurality of permanent magnets 140 provided at a distance from the rotor core 131 in a circumferential direction and extending over the entire axis O direction, and the permanent magnets 140 extend so as to be inclined inward in the radial direction toward the downstream side and have a width in the circumferential direction that decreases toward the downstream side.

[0184] As a result, the configuration of the rotor may have a conical shape corresponding to the shape of the shell 50 with the decreasing diameter.

[0185] (14) A fluid machine according to a fourteenth aspect is the fluid machine according to (13), in which a magnetization direction of the permanent magnets 140 is perpendicular to an outer surface of the rotor.

[0186] The magnetization direction of the permanent magnet 140 corresponds to the direction in which the rotor and stator point, rather than simply being in the radial direction, which can improve the torque of the motor.

[0187] (15) A fluid machine according to a fifteenth aspect is the fluid machine according to (13) or (14), in which the propeller further includes an outer peripheral ring 30 having an annular shape constituting the outer peripheral portion of the propeller, the rotor core 131 is attached to an outer surface of the outer peripheral ring 30, and the fluid machine further includes a retaining plate in contact with end portions of the outer peripheral ring 30 and the rotor core 131 on the downstream side, and a retaining bolt 151 provided through the retaining plate in the axis-O direction and fixing the retaining plate to the outer peripheral ring 30.

[0188] The electromagnetic force toward the outside in the radial direction and the downstream side acts on the rotor core 131 of the conical motor 90. In view of this, the rotor core 131 is held by the holding plate from the downstream side and thus prevents falling off.

[0189] (16) A fluid machine according to a sixteenth aspect is the fluid machine according to (15), in which the outer peripheral ring 30 has a thickness in the radial direction that decreases toward the downstream side, and a notched portion 135 is formed in a portion between adjacent ones of the permanent magnets 140 at an end portion of the rotor core 131 on the downstream side, the notched portion 135 receiving a part of an outer surface of the holding bolt 151 inserted into the holding plate.

[0190] The thickness of the downstream end of the outer peripheral ring 30 in the radial direction is small. Thus, the bolt hole 36 cannot be formed in a portion of the downstream end of the outer peripheral ring 30 depending on the diameter of the bolt. On the other hand, the notched portion 135, which receives a part of the outer surface of the retaining bolt 151, is formed in the rotor. Thus, insertion of the retaining bolt 151 is possible, so that the retaining bolt 151 can be adequately fixed with respect to the outer peripheral ring 30.

[0191] The movement of the rotor core 131 relative to the outer peripheral ring 30 in the circumferential direction can be limited by the notched portion 135.

[0192] In addition, with the notched portion 135 formed in a portion between the permanent magnets 140 in the rotor core 131, hollowing of the magnetic path of the rotor core 131 can be minimized, whereby the increase in magnetic resistance can be suppressed.

[0193] (18) An underwater vehicle 1 according to an eighteenth aspect includes: a vehicle body 2; and a thruster 8 provided on the vehicle body 2, wherein the thruster 8 is the fluid machine described in any one of (1) to (15).

[0194] With this underwater vehicle 1, the thruster 8 can be made compact while the thrust efficiency is improved. 1 underwater vehicle 2 vehicle body 3 wave section 3a Shaft outer surface 5 Recording groove 5a Groove bottom surface 5b upstream groove surface 5c downstream groove surface 8 pusher (fluid machine) 10A first propeller (propeller) 10B second propeller (propeller) 11 Inner circumferential ring 12 Ring inner surface 13 upstream end surface 14 downstream end surface 15 Outer peripheral flow path surface 20A first rotor blade (rotor blade) 20B second rotor blade (rotor blade) 30 outer circumference ring 31 Inner circumferential flow path surface 32 cylindrical fixation surface 33 conical fixation surface 34 stopping section 35 \ downstream end surface 36 bolt hole 40 storage section 41 radial bearings 42 upstream thrust bearing 43 downstream thrust bearing 50 coat 50A first cavity 50B second cavity 51 Sheath inner surface 52 Outer shell surface 53 Jacket leading edge 54 Jacket trailing edge 56 cylindrical fixing recess section 57 conical fixation recess section 61 upstream segment (segment) 62 Intermediate segment (segment) 63 downstream segment (segment) 70 coupling section 70a protruding section of the leading edge 70b protruding section of the trailing edge 71 upstream projecting section 71a Bolt fixing hole 72 preceding intermediate section 72a Bolt through hole 73 downstream projecting section 73a Bolt recess section 73b Bolt insertion hole 74 coupling bolts 75 filling section 78 Strut 80 tubular engine (engine) 81 tubular stator 82 tubular rotor 83 first retaining plate 90 conical engine (engine) 100 conical stator (stator) 101 Stator core 102 Stator outer surface 103 Stator inner surface 104 Back yoke 106 tooth 107 tooth bodies 108 distal tooth end section 110 coil 111 Coil end 112 Coil main section 120 coil layers 121 upstream part 122 downstream part 123 side panel 130 conical rotor (rotor) 131 Rotor core 132 Rotor inner surface 133 Rotor outer surface 134 insertion hole 135 notched section 140 permanent magnet 141 Magnet outer surface 142 Magnet inner surface 143 Magnetic side surface 144 upstream magnet surface 145 downstream magnet surface 150 second retaining plate 150a bolt stop hole 151 retaining bolts O axis< / wirkungsweise> < / spulen> < / statorkern> < / streben> < / kopplungsabschnitt> < / mantel> < / lagerabschnitte> < / innenumfangsring> < / wellenabschnitt> < / schubapparat>

Claims

[1] Fluid machine (8), comprising: a shaft portion (3) extending in an axial direction; a shell (50) provided to surround the shaft portion and having a diameter that decreases from an upstream side on one side in the axial direction to a downstream side on another side in the axial direction, wherein a flow path is formed between the shell and the shaft portion and has a flow path cross-sectional area that decreases towards the downstream side, a propeller (10A, 10B) rotatably provided about an axis (O) between the shaft portion and the shell and configured to pump a fluid from the upstream side toward the downstream side; and a motor (80, 90) associated with the propeller, the motor including a rotor (82, 130) having an annular shape and fixed to an outer peripheral portion of the propeller and housed in the shroud, and a stator (100) having an annular shape surrounding the rotor and fixed in the casing, wherein the motor is a conical motor in which the diameters of the rotor and the stator decrease from the upstream side to the downstream side, and the fluid machine is characterized in that the shell includes a plurality of longitudinal sections (61, 62, 63) of the shell which are divided into several parts in the axial direction, and the fluid machine further includes a coupling portion (70) configured to couple the plurality of longitudinal portions (61, 62, 63) in the axial direction, and the coupling portion has a convex curved shape protruding from an outer surface of the shell, and the cross-section of the coupling section along the outer surface of the shroud represents a symmetrical airfoil, the upstream side being a leading edge and the downstream side being a trailing edge. [2] A fluid machine according to claim 1, wherein the stator of the conical motor includes: a stator core (101) including a back yoke (104) forming an annular shape around the axis and having a diameter that decreases towards the downstream side, and a plurality of teeth (106) projecting from an inner surface of the back yoke to an inner side in a radial direction, extending in a circumferential direction over the entire axial direction, and having a thickness in the circumferential direction that decreases with a decreasing diameter that decreases toward the downstream side, and a plurality of coils (110) provided to surround an outer surface of each of the teeth. [3] Fluid machine (8), comprising: a shaft portion (3) extending in an axial direction; a shell (50) provided to surround the shaft portion and having a diameter that decreases from an upstream side on one side in the axial direction to a downstream side on another side in the axial direction, wherein a flow path is formed between the shell and the shaft portion and has a flow path cross-sectional area that decreases towards the downstream side, a propeller (10A, 10B) rotatably provided about an axis (O) between the shaft portion and the shell and configured to pump a fluid from the upstream side toward the downstream side; and a motor (80, 90) associated with the propeller, the motor including a rotor (82, 130) having an annular shape and fixed to an outer peripheral portion of the propeller and housed in the shroud, and a stator (100) having an annular shape surrounding the rotor and fixed in the casing, wherein the motor is a conical motor in which the diameters of the rotor and the stator decrease from the upstream side to the downstream side, and the fluid machine is characterized in that the stator of the conical motor includes: a stator core (101) including a back yoke (104) forming an annular shape around the axis and having a diameter that decreases towards the downstream side, and a plurality of teeth (106) projecting from an inner surface of the back yoke to an inner side in a radial direction, extending in a circumferential direction over the entire axial direction, and having a thickness in the circumferential direction that decreases with a decreasing diameter that decreases toward the downstream side, and a plurality of coils (110) provided to surround an outer surface of each of the teeth. [4] Fluid machine according to claim 3, wherein each of the coils includes a rectangular copper wire having a flat shape with a plurality of layers stacked in a radial direction around the teeth, and each layer of the coil has a rectangular shape with a distance in the circumferential direction which decreases towards the downstream side when viewed in the radial direction. [5] A fluid machine according to claim 4, wherein each layer of the coil is inclined radially inward toward the downstream side. [6] A fluid machine according to claim 5, wherein the axial direction positions of end portions of coil ends (111) of each coil in the axial direction in each layer correspond to each other. [7] A fluid machine according to claim 6, wherein a portion of each layer of the coil forming the coil end (111) is bent to be parallel to the axis. [8] Fluid machine (8), comprising: a shaft portion (3) extending in an axial direction; a shell (50) provided to surround the shaft portion and having a diameter that decreases from an upstream side on one side in the axial direction to a downstream side on another side in the axial direction, wherein a flow path is formed between the shell and the shaft portion and has a flow path cross-sectional area that decreases towards the downstream side, a propeller (10A, 10B) rotatably provided about an axis (O) between the shaft portion and the shroud and configured to pump a fluid from the upstream side toward the downstream side; and a motor (80, 90) associated with the propeller, the motor including a rotor (82, 130) having an annular shape and fixed to an outer peripheral portion of the propeller and housed in the shroud, and a stator (100) having an annular shape surrounding the rotor and fixed in the casing, wherein the motor is a conical motor in which the diameters of the rotor and the stator decrease from the upstream side to the downstream side, and the fluid machine is characterized in that the rotor of the conical motor includes: a rotor core (131) forming an annular shape around the axis and having a diameter that decreases towards the downstream side and a plurality of permanent magnets (140) provided at a distance from the rotor core in a circumferential direction and extending over the entire axial direction, the permanent magnets extend so as to be inclined radially inward toward the downstream side and have a width in the circumferential direction which decreases toward the downstream side, and a magnetization direction of the permanent magnets is perpendicular to an outer surface of the rotor, and the propeller further comprises an outer peripheral ring (30) having an annular shape forming the outer peripheral portion of the propeller, the rotor core is attached to an outer surface of the outer peripheral ring, and the fluid machine further includes: a holding plate (83, 150) in contact with end portions of the outer peripheral ring and the rotor core on the downstream side; and a retaining bolt (151) provided extending in the axial direction through the retaining plate and fixing the retaining plate to the outer peripheral ring. [9] Fluid machine according to claim 8, wherein the outer peripheral ring has a thickness in the radial direction which decreases towards the downstream side, and a notched portion (135) is formed in a portion between adjacent ones of the permanent magnets at an end portion of the rotor core on the downstream side, the notched portion receiving a part of an outer surface of the holding bolt inserted into the holding plate. [10] A fluid machine according to any one of claims 1 to 9, wherein the cross section of the shroud passing through the axis has a blade shape, with an end portion on the upstream side corresponding to a leading edge and an end portion on the downstream side corresponding to a trailing edge. [11] A fluid machine according to any one of claims 1 to 10, wherein two of the propellers are provided in the axial direction, the rotation directions of the two propellers are opposite to each other, one motor is provided for each of the two propellers, and at least one of the two motors is the conical motor. [12] Fluid machine according to claim 11, wherein each of the propellers includes a plurality of blades (20A, 20B) arranged in a circumferential direction, a suction-side pressure distribution of the rotor blade (20B) of the propeller (10B) on the downstream side is a leading edge load, the load being concentrated at a leading edge, and a suction-side pressure distribution of the rotor blade (20A) of the propeller (10A) on the upstream side is a balanced load, wherein the load is more distributed in the axial direction than in the suction-side pressure distribution of the rotor blade on the downstream side, wherein the load on an inner side in the radial direction is smaller. [13] Fluid machine according to one of claims 1 to 10, wherein the propeller includes an inner peripheral ring (11) attached to an outer peripheral side of the shaft portion via a clearance, and the fluid machine further includes: a thrust bearing (42, 43) fixed to the shaft portion and facing the upstream side of the inner peripheral ring over an entire circumferential direction; and a strut (78) supporting the shell relative to the shaft portion. [14] Underwater vehicle (1), comprising: a vehicle body (2); and a thrust device (8) provided on the vehicle body, wherein the thrust device is the fluid machine (8) described in any one of claims 1 to 13.

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