Fluid machine and underwater vehicle

Abstract

Fluid machine (8), comprising: a shaft section (3) extending in an axial direction; a shell (50) provided to surround the shaft portion and having a shell inner surface (51) with a diameter decreasing axially from an upstream side on one side to a downstream side on another side, a flow path being formed between the shell and the shaft portion and having a flow path cross-sectional area decreasing toward the downstream side, a plurality of propellers (10A, 10B) rotatably provided about an axis (O) between the well portion and the shell and configured to pump a fluid from the upstream side toward the downstream side; and a like plurality of motors (80, 90) associated with the respective propellers and each including a rotor (82, 130) having an annular shape, fixed to an outer peripheral portion of the propeller and housed in the shell, and having a Stator (81, 100) having an annular shape surrounding the rotor (82, 130) and fixed in the shell, wherein the propellers are spaced apart from each other in the axial direction, and the rotor of the motor positioned furthest downstream has a smaller average outer diameter, the fluid machine is characterized in that the shell includes a plurality of longitudinal sections (61, 62, 64) which are divided axially into a plurality of parts, the fluid machine further includes a coupling portion (70) coupling the plurality of segments in the axial direction, the coupling portion has a convex curved shape protruding from an outer surface of the shell, and the cross-section along the outer surface of the shell of the coupling section 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. State of the art

[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 tubular shell formed around the axis and propellers arranged coaxially on the inside of the shell. Two propellers are arranged in the axial direction.

[0003] The shell accommodates a total of two motors, corresponding to the two respective propellers. Each motor includes a rotor provided on an outer peripheral portion of the propeller and a stator surrounding the rotor from the outer peripheral side. The motor and stator each have a tubular shape, with the outer and inner surfaces parallel to the axis. Furthermore, the two motors are arranged side by side, with their radial direction positions being the same.

[0004] These motors implement the outer peripheral drive of the propellers to pump a fluid axially within the hull.

[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, and 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, resulting in the flow of the fluid being narrowed in the radial direction toward the inside. In view of this, a flow path in which such a fluid flows preferably has a shape that narrows correspondingly toward the downstream side, i.e., the flow path has a flow path cross-sectional area that decreases toward the downstream side. However, the thrust apparatus described in US Pat. No. 8,074,592 B2 is configured to have the flow path cross-sectional area on the inside of the shell toward the downstream side. Thus, the configuration is undesirable in terms of propeller efficiency.

[0007] When implementing the outer peripheral drive using a plurality of motors, the plurality of motors must be arranged within the casing. Depending on the arrangement structure of the plurality of motors, the casing may need to be enlarged to accommodate the arrangement. 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, thereby also achieving an improvement in efficiency.

[0009] The present invention is defined by the subject matter of independent claims 1, 6 and 11. The subclaims define preferred embodiments.

[0010] In order to solve the problems described above, a fluid machine according to the invention includes: a shaft portion extending in an axial direction; a shell provided to surround the shaft portion and having an inner surface with 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, a flow path formed between the shell 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 shell and configured to pump a fluid from the upstream side toward the downstream side;a motor provided so as to correspond to the propeller, and including a rotor having an annular shape fixed to an outer peripheral portion of the propeller and housed in the shell, and a stator having an annular shape surrounding the rotor and fixed in the shell, in which a plurality of the propellers are provided so as to be spaced apart from each other in the axial direction, the motors are provided in the same number as the propellers to correspond to each of the propellers, and of a plurality of motors, the rotor of the motor positioned more on the downstream side has an averagely smaller outer diameter;

[0011] The present disclosure can provide a fluid machine and an underwater vehicle that can be made compact, thereby also achieving an improvement in efficiency. Brief Description of the Drawings Fig. 1 is a perspective view of the stern 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 drawing illustrating a suction-side pressure distribution of a first blade, Fig. 4(b) is a drawing 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 outside in a 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. Figure 11 is a two-dimensional drawing 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 the embodiments< General configuration of the underwater vehicle >

[0012] 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>

[0013] 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,

[0014] Communication devices, sensors and the like, which are necessary for underwater travel, for example. <schubapparat>

[0015] 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.

[0016] The thruster 8 includes a shaft section 3, a first propeller 10A, a second propeller 10B, bearing sections 40, a shell 50, coupling sections 70, struts 78, a tubular motor 80 and a conical motor 90. <schachtabschnitt>

[0017] As in Fig. 2, the duct portion 3 is integrally provided in the rear portion of the vehicle body 2. The duct portion 3 may be part of the vehicle body 2. The duct portion 3 has a rod shape extending along the axis O. The duct 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 duct portion 3 facing an outer side in a radial direction is a duct outer surface 3a having a conical shape with a diameter that decreases toward the other side in the axis O.

[0018] 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.

[0019] 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.

[0020] A surface forming the receiving groove 5 on one side in the axis O direction is a groove upstream side surface 5b. The groove upstream side surface 5b has a flat shape perpendicular to the axis O and faces the other side in the axis O direction. The groove upstream side surface 5b extends annularly around the axis O.

[0021] A surface forming the receiving groove 5 on the other side in the axis O direction is a groove downstream side surface 5c. The groove downstream side surface 5c has a flat shape perpendicular to the axis O and faces one side in the axis O. The groove downstream side surface 5c extends annularly around the axis O. The groove downstream side surface 5c is parallel to the groove upstream side surface 5b. <Erster Propeller und zweiter Propeller>

[0022] 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>

[0023] 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.

[0024] As in Fig. As illustrated in Figure 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. The ring inner surface 12 forms an inner surface of the inner peripheral ring 11. The ring inner surface 12 forms a cylindrical shape that faces the groove bottom surface 5a entirely across the 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.

[0025] The upstream end surface 13 is a surface of the inner peripheral ring 11 facing one side in the axis O direction, and is arranged on the other side of the groove upstream side surface 5b in the axis O direction with a clearance therebetween.

[0026] The downstream end surface 14 is a surface of the inner peripheral ring 11 facing the other side in the axis O direction, and is arranged on one side of the groove downstream side surface 5c in the axis O direction with a clearance therebetween.

[0027] 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>

[0028] The first moving blade 20A is provided to extend radially from the outer peripheral flow path surface 15 of the inner peripheral ring 11 of the first propeller 10A to the outside. The second moving blade 20B is provided to extend radially from the outer peripheral flow path surface 15 of the inner peripheral ring 11 of the second propeller 10B to the outside. 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.

[0029] 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.

[0030] 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.

[0031] 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 portion in the axis-O direction.

[0032] As in Fig. As illustrated in Fig. 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.

[0033] As described above, the suction-side pressure distribution of the second moving blade 20B is of the leading-edge load type, with the load concentrated on the leading edge. On the other hand, the suction-side pressure distribution of the first moving blade 20A is of a balanced load type, with the load being more distributed in the axis-O direction than in the suction-side pressure distribution of the second moving blade 20B, and the load on the inner side in the radial direction is smaller. <Außenumfangsring>

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] An average outer diameter of the tapered fixing surface 33 is set smaller than the average outer diameter of the cylindrical fixing surface 32. In the present embodiment, the tapered fixing surface 33 extends to form a uniform conical shape in the axis O direction. Thus, the average outer diameter of the tapered fixing surface 33 is the same as the outer diameter of the tapered fixing surface 33 at the center in the axis O direction. The average outer diameter of the cylindrical fixing surface 32 is the same as the outer diameter of any portion of the cylindrical fixing surface 32 in the axis O direction.In the present embodiment, the outer diameter of the end portion of the tapered fixing surface 33 on the upstream side is set to be equal to or smaller than the outer diameter of the end portion of the cylindrical fixing surface 32 on the downstream side.

[0040] The holding portion 34 projects radially from each of the upstream-side end portion of the cylindrical fixing surface 32 and the upstream-side end portion of the tapered fixing surface 33 in each outer peripheral ring 30 to the outside and extends entirely in the circumferential direction. <lagerabschnitte>

[0041] The bearing portions 40 support the first propeller 10A and the second propeller 10B 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.

[0042] The radial bearing 41 is provided on the groove bottom surface 5a of the receiving groove 5 entirely over the 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 entirely over the circumferential direction between the journal bearing and the inner peripheral ring 11.

[0043] The upstream side thrust bearing 42 is provided on the groove upstream side surface 5b of the receiving groove 5 entirely over the 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.

[0044] The downstream side thrust bearing 43 is provided on the groove downstream side surface 5c of the receiving groove 5 entirely over the circumferential direction. The downstream side thrust bearing 43 faces the downstream end surface 14 of the inner peripheral ring 11 via the clearance in the axis O direction.

[0045] 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. <Hülle>

[0046] The shroud 50 is provided 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 entirely across the axis O direction between the shroud 50 and the shaft portion 3. The first blades 20A of the first propeller 10A and the second blades 20B of the second propeller 10B are positioned 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.

[0047] The surface of the shroud 50 facing the inner side 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 outer side in the radial direction is a shroud outer surface 52. 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 that extends 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 that extends annularly in the circumferential direction.The position of the shell rear edge 54 in the axis O direction is equal to the position of the rear end of the shaft section 3 in the axis O direction.

[0048] 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 toward the inside in the radial direction toward the downstream side from the upstream side. Thus, the shroud trailing edge 54 is positioned more toward the inside in the radial direction than the shroud leading edge 53.

[0049] The outer shell surface 52 has a diameter that first increases toward the downstream side in a portion around the leading edge 53 of the shell and then decreases smoothly toward the downstream side. The outer shell surface 52 forms a convex curved shape that protrudes toward the outside in the radial direction.

[0050] The shell inner surface 51 has a diameter that decreases on the inner side in the radial direction toward the downstream side completely across the axis O direction. The shell inner surface 51 forms a convex curved shape that protrudes toward the inner side in the radial direction. The annular flow path formed between the shell inner surface 51 and the shell outer surface 3a of the shaft section 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.

[0051] The shroud inner surface 51 does not need to have a diameter that decreases 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.

[0052] Thus, the flow path cross-sectional area of ​​the flow path formed by the shroud inner surface 51 and the shaft outer surface 3a does not need to have a diameter that gradually decreases in the axis-O direction throughout the entire 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.

[0053] 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 more on the downstream side than the first cavity 50A.

[0054] 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 shell 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 shell inner surface 51.

[0055] 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.

[0056] 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.

[0057] The average inner diameter of the lower portion of the tapered fixing groove portion 57 is set smaller than the average inner diameter of the lower portion of the cylindrical fixing groove portion 56. The lower portion of the tapered fixing groove portion 57 extends in the axis O direction with a uniform taper angle. Thus, the average inner diameter of the lower portion of the tapered fixing groove portion 57 matches the inner diameter of the lower portion of the tapered fixing groove portion 57 at the center in the axis O direction.The lower portion of the cylindrical fixing recess portion 56 forms a cylindrical shape parallel to the axis O direction, and thus the average inner diameter of the cylindrical fixing recess portion 56 is the same as the inner diameter of any portion of the lower portion of the cylindrical fixing recess portion 56 in the axis O direction.

[0058] It should be noted that "average inner diameter" means the average inner diameter in the axis-O direction.

[0059] 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.

[0060] The upstream segment 61 forms a section on the upstream side including the shell leading edge 53. The intermediate segment 62 forms a section that is 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 radially inner side and on the downstream side from the downstream side. The downstream segment 63 forms a section that is continuous to the downstream side of the intermediate segment 62 and forms a section that includes the shell trailing edge 54. The second cavity 50B is defined and formed by intermediate segment 62, which closes from the upstream side a largely notched part of the downstream segment 63 on the inside in the radial direction and on the upstream side. <kopplungsabschnitt>

[0061] As in Fig. 1, the coupling portions 70 are provided to protrude from the shell outer surface 52 of the shell 50. The coupling portions 70 couple the plurality of segments of the shell 50 together.

[0062] 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.

[0063] The upstream protruding portion 71 is integrally provided with 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.

[0064] 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.

[0065] 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.

[0066] 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 positioned 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.

[0067] 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 when resin in a liquid form is poured into the bolt recess portion 73a after the coupling bolt 74 is fastened and the resin has cured. A part of the filling portion 75 forms the outer surface of the coupling portion 70.

[0068] 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.

[0069] Furthermore, as in Fig. As illustrated in Fig. 6, the coupling portion 70 of the present embodiment has a cross-sectional shape, along the shroud outer surface 52, in a blade shape 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 protruding portion of the leading edge 70a. The trailing edge of the coupling portion 70 is a protruding 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>

[0070] As in Fig. 1 and Fig. As illustrated in Figure 2, the struts 78 support the shell 50 with respect to the shaft portion 3 by coupling the shell 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 shell 50. The upstream side end portion of the strut 78 is fixed to the shaft outer surface 3a of the shaft portion 3.

[0071] The cross-sectional shape of the strut 78 perpendicular to the axis O is a flat rectangular shape with the longitudinal direction consistent with the radial direction and the shorter direction consistent with the circumferential direction. Thus, the rotation of the thrust of the underwater vehicle 1 is suppressed. <rohrmotor>

[0072] As in Fig. 2 and Fig. 3, the tubular motor 80 is housed in the first cavity 50A of the shell 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.

[0073] 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 tubular stator 81 has the outer surface 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. The outer diameter of the outer surface of the tubular stator 81 is the same as the inner diameter of the bottom surface of the cylindrical fixing recess portion 56 entirely across the axis O direction.

[0074] 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. Thus, the inner diameter of the tubular rotor 82 and the outer diameter of the cylindrical fixing surface 32 are the same throughout the axis O direction. The outer surface of the tubular rotor 82 faces the inner surface of the tubular stator 81 throughout the circumferential direction and the axis O direction.A clearance is formed entirely over the circumferential direction and the axis O direction between the outer surface of the tubular rotor 82 and the inner surface of the tubular stator 81.

[0075] The upstream side end surface of the tubular rotor 82 contacts the holding portion 34 in the outer peripheral ring 30 of the first propeller 10A from the downstream side. A first holding plate 83 contacts the downstream side end surface of the tubular rotor 82. The first holding 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. With the first holding plate 83 fixed to the outer peripheral ring 30 using an unillustrated bolt, the tubular rotor 82 is fixed by the first holding plate 83 from the downstream side.

[0076] In the tubular motor 80, when the tubular stator 81 is excited, 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 shell 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 is inclined toward the inside in the radial direction toward the downstream side. 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. The outer diameter of the stator outer surface 102 and the inner diameter of the lower portion of the tapered fixing recess portion 57 are equal at every position in the axis O direction and are thus completely equal across the axis O direction. <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 teeth 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 teeth body 107 on the inner side in the radial direction and extending to both sides in the circumferential direction from the teeth 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 toward the inner side in the radial direction 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 cone angles of the stator inner surface 103 and the stator outer surface 102 are equal and completely constant along the axis O direction. Thus, in the cross-section including the axis O, the stator inner surface 103 and the stator outer surface 102 are parallel to each other.

[0084] 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>

[0085] A plurality of coils 110 are provided to surround the respective teeth 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 teeth body 107, the coil as a whole is provided to the outer surface of the teeth body 107.

[0086] 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 crimped in an extending direction of the teeth body 107, and thus is a flat shape with the shorter direction consistent with the radial direction.

[0087] The coil layer 120 has a rectangular annular shape surrounding the teeth body 107, as shown in Fig. 9, according to the cross-sectional shape of the teeth 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 teeth body 107 from the upstream side.

[0088] A portion of the coil layer 120 extending in the circumferential direction on the downstream side is a downstream part 122 that contacts the teeth 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.

[0089] A pair of portions of the coil layer 120 extending on both sides of the teeth 106 circumferentially in the axis O direction are each a side part 123. The pair of side parts 123 are in contact with the teeth 106 from both sides in the circumferential direction and extend closer to each other toward the downstream side.

[0090] Each coil 110 forms a spiral winding around the teeth body 107, with the plurality of coil layers 120 being electrically connected to each other and stacked in the radial direction.

[0091] 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.

[0092] In the present embodiment, as shown in Fig. 8 illustrates that portions of the coil 110 constituting the coil main portion 112 and the coil end 111 on the downstream side are inclined toward the inside in the radial direction toward the downstream side. Thus, the side portions 123 and the downstream portion 122 of each coil layer 120 are arranged to be inclined toward the inside in the radial direction toward the downstream side.

[0093] On the other hand, 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.

[0094] 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 the coil layers 120. The end portions of the coil ends 111 in the axis O direction are arranged to be the axis O direction positions that are the same among the coil layers 120. <Konischer Rotor>

[0095] 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.

[0096] 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 is inclined toward the inside 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. The cone angles of the rotor inner surface 132 and the rotor outer surface 133 are equal and completely constant throughout the axis O direction. Thus, in the cross section including the axis O, the rotor inner surface 132 and the rotor outer surface 133 are parallel to each other.

[0097] 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. The inner diameter of the rotor inner surface 132 and the outer diameter of the tapered fixing surface 33 are the same at any position in the axis O direction, and are thus completely uniform throughout the axis O direction.

[0098] 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 insertion holes 134 are provided at a distance in the circumferential direction. The insertion hole 134 extends parallel to the rotor inner surface 132 and the rotor outer surface 133. In other words, the insertion hole 134 extends toward the inside in the radial direction, inclined toward the downstream side. 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>

[0099] 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.

[0100] 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 toward the inside in the radial direction toward the downstream side. 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.

[0101] 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.

[0102] The surface of the permanent magnet 140 facing the upstream side is a magnet upstream surface 144. The magnet upstream surface 144 has a planar shape perpendicular to the axis O. The magnet upstream 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.

[0103] The downstream side surface of the permanent magnet 140 is a magnet downstream surface 145. The magnet downstream surface 145 has a planar shape perpendicular to the axis O and is parallel to the magnet upstream surface 144. The magnet downstream 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.

[0104] 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.

[0105] 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 excited. The direction of rotation of the conical motor 90 is opposite to the direction of rotation of the tubular motor 80. Thus, the directions of rotation of the conical motor 90 and the tubular motor 80 are opposite to each other.

[0106] 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.

[0107] The downstream side end portion of the conical rotor 130 is held by a second holding plate 150 from the downstream side.

[0108] 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 that extends entirely across the 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.

[0109] This second retaining plate 150 is fixed to the outer peripheral ring 30 by a retaining bolt 151. The retaining bolt 151 is fixed to a bolt stop hole 150a formed to be recessed from the downstream end surface 35 of the outer peripheral ring 30 after being inserted from the downstream side into the bolt stop hole 150a formed by the second retaining plate 150 in the axis O.

[0110] 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 the adjacent ones of the permanent magnets 140 in the circumferential direction in the rotor core 131.

[0111] An average outer diameter R2 of the conical rotor 130 of the conical motor 90 is set to be smaller than an average outer diameter R1 of the tubular rotor 82 of the tubular motor 80. In the present embodiment, the outer surface (rotor outer surface 133) of the conical rotor 130 extends with a uniform taper angle in the axis O direction. Thus, the average outer diameter R2 of the conical rotor 130 is the same as the outer diameter of the conical rotor 130 at the center in the axis O direction. With the tubular rotor 82 having a uniform outer diameter in the axis O direction, the average outer diameter R1 of the tubular rotor 82 is the same as the outer diameter of the tubular rotor 82 at any portion in the axis O direction.

[0112] The average inner diameter of the conical stator 100 of the conical motor 90 is set smaller than the average inner diameter of the tubular stator 81 of the tubular motor 80. In the present embodiment, the inner surface of the conical stator 100 extends with a uniform cone angle in the axis O direction. The average inner diameter of the conical stator 100 is the same as the inner diameter of the conical stator 100 at the center in the axis O direction. With the tubular stator 81 having a uniform inner diameter in the axis O direction, the average inner diameter of the tubular stator 81 is the same as the inner diameter of the tubular stator 81 at any portion in the axis O direction.

[0113] The average inner diameter of the conical motor 90 (the average inner diameter of the conical rotor 130: the inner diameter of the conical rotor 130 at the center in the axis O direction) is set smaller than the average inner diameter of the tubular motor 80 (tubular rotor 82) (the average inner diameter of the tubular rotor 82: the inner diameter of the tubular rotor 82 at any portion in the axis O direction).

[0114] In the present embodiment, the inner diameter of the upstream end portion of the inner surface of the conical motor 90 is equal to or smaller than the inner diameter of the downstream end portion of the inner surface of the tubular motor 80. That is, the inner diameter of the upstream end portion of the inner surface of the conical motor 90 is set to be equal to the downstream end portion of the inner surface of the tubular motor 80, or is set to be smaller than the inner diameter of the downstream end portion of the inner surface of the tubular motor 80.

[0115] The average outer diameter of the conical motor 90 (the average outer diameter of the conical stator 100: the outer diameter of the conical stator 100 at the center in the axis O direction) is set smaller than the average outer diameter of the tubular motor 80 (tubular stator 81) (the average outer diameter of the tubular stator 81: the outer diameter of the tubular stator 81 at any section in the axis O direction).

[0116] In the present embodiment, the outer diameter of the upstream end portion of the outer surface of the conical motor 90 is equal to or smaller than the outer diameter of the downstream end portion of the outer surface of the tubular motor 80. Specifically, the outer diameter of the upstream end portion of the outer surface of the conical motor 90 is set to be equal to the outer diameter of the downstream end portion of the outer surface of the tubular motor 80, or is set to be smaller than the outer diameter of the downstream end portion of the outer surface of the tubular motor 80.

[0117] As described above, in the present embodiment, the average diameter of the conical motor 90, which is the motor on the downstream side, is set smaller than the average diameter of the tubular motor 80, which is the motor on the upstream side. Thus, an arrangement structure is obtained in which the conical motor 90, which is the motor on the downstream side, is displaced more radially on the inside than the tubular motor 80, which is the motor on the upstream side. <betriebseffekte>

[0118] The underwater vehicle 1 with the above-described configuration can be propelled underwater with the thruster 8. Specifically, when the tubular motor 80 is driven in the first cavity 50A of the hull 50, the first propeller 10A, which is integrally fixed 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 moving 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 fixed 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 moving blades 20B positioned in the flow path.

[0119] Then, the upstream thrust force 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 well section 3 via the water film and the upstream side thrust bearing 42. Thus, the thrust force acts on the well section 3 and the connected vehicle body 2, thereby propelling the underwater vehicle 1.

[0120] In the drive apparatus 8 of the present embodiment, as shown in Fig. 2 and Fig. 3, the shell 50 has a diameter that decreases toward the downstream side, and the shaft portion 3 has a diameter that decreases toward the downstream side. Thus, the flow path formed between the shell 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.

[0121] When water is pumped through the first moving blades 20A and the second moving blades 20B, the water flow velocity increases, resulting in the water flow being narrowed in the radial direction on the inner side. In the present embodiment, the flow path has a shape suitable for the water flow, thereby improving the water pumping efficiency.

[0122] Since the inner surface of the shell 50 has a diameter that decreases toward the downstream side, the average diameter of the conical motor 90 positioned on the downstream side is set smaller than the average diameter of the tubular motor 80 positioned on the upstream side. Thus, an arrangement structure is obtained in which the motor on the downstream side is shifted more toward the inside in the radial direction than the motor on the upstream side.

[0123] When a plurality of motors have the same average outer diameter, that is, when the motors with the same diameter are simply arranged side by side in the axis O direction, the plurality of motors are arranged in the axis O direction to conflict with the shape of the inner surface of the shell 50 as the diameter decreases. In this case, the conflict between the shape of the shell 50 and the arrangement structure of the plurality of motors requires the shell 50 to adapt to the arrangement structure of the motors. Thus, the shell 50 may need to be undesirably larger.

[0124] In view of this, in the present aspect, as described above, the arrangement structure includes the conical rotor 130, which is the motor on the downstream side, with the inner side further shifted in the radial direction, and the arrangement structure corresponds to the shape of the shell 50 with the decreasing diameter. Thus, the shape of the shell 50 does not need to be enlarged to adapt to the arrangement of the motors, whereby a compact configuration can be achieved.

[0125] In the present embodiment, the overall shape of the shell 50 has a diameter gradually decreasing toward the downstream side, thus having a tapered shape to have a smaller diameter 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.

[0126] In the present embodiment, since the hull 50 thus has a compact configuration, the resistance in the water during propulsion of the underwater vehicle 1 is small. Thus, the speed of the underwater vehicle 1 can be increased and the propulsion efficiency can be improved.

[0127] 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 toward the inside in the radial direction toward the downstream side, and the shroud 50 as a whole, which forms the blade shape, has a tapered shape with the 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.

[0128] The conical motor 90 disposed within the hull 50 has a tapered shape that conforms to the shape of the hull 50, eliminating the need to inconveniently enlarge the blade-shaped shape of the hull 50 to accommodate the conical motor 90. Thus, the hull 50 can have a compact shape while maintaining the blade shape. Thus, resistance in water during propulsion can be minimized.

[0129] When the water is sucked in, the resistance in water tends to increase due to the pressure disturbance between the first blades 20A of the first propeller 10A positioned on the upstream side and the shaft section 3. In particular, a configuration in which the load is concentrated over the entire leading edge of each blade to improve propeller efficiency results in significant resistance in water.

[0130] On the other hand, in the present embodiment, as shown in Fig. 4 illustrates the load distribution on the suction side of the first blade 20A of a balanced load type in which the load is distributed in the axis O direction, with the load on the inner side in the radial direction being small. Thus, an increase in fluid resistance due to pressure disturbance can be minimized.

[0131] 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 disturbance with the shaft portion 3, is of a leading edge load type in which the load is concentrated on the leading edge, so that the propeller efficiency can be improved.

[0132] As in Fig. 3, the thrust of the first propeller 10A and the second propeller 10B is transmitted to the shaft section 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. In the present embodiment, when the conical motor 90 is driven, the electromagnetic force acts in the direction (column direction) facing the conical rotor 130 and the conical stator 100 of the conical motor 90. The electromagnetic force is in a direction toward the outside in the radial direction and toward the downstream side. Thus, the force toward the downstream side is applied to the conical rotor 130 as a component of the electromagnetic force in the axis O direction.

[0133] 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.

[0134] Furthermore, in the present embodiment, by decoupling the Fig. 5, the shell 50 can 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 tubular motor 80 shown in Fig. 3 can be easily mounted in the casing 50.

[0135] 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 shell 50, and the cross-sectional shape along the outer surface of the shell 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, resistance due to the coupling portion 70 can be suppressed while the underwater vehicle 1 is propelled.

[0136] The conical stator 100 of the conical motor 90 of the present embodiment is housed in the second cavity 50B, and is fixed only to the second cavity 50B of the downstream side segment 63 between the intermediate segment 62 and the downstream segment 63 defining the second cavity 50B. The downstream side force, which is a component of the electromagnetic force, acts on the conical rotor 130 as described above, while the upstream side force, which is a component of the electromagnetic force, acts on the conical stator 100 paired with the conical rotor 130. Thus, the upstream side force also acts on the downstream segment 63 to which the conical stator 100 is integrally attached.

[0137] 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.

[0138] The conical stator 100 of the conical motor 90 has a tapered shape that matches the shape of the shell 50. This helps keep the shell 50 compact while providing the function of the motor's stator.

[0139] 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.

[0140] In addition, as in Fig. 8 illustrates, the coil layers 120 constituting the respective layers of the coil 110 are inclined toward the inside in the radial direction toward the downstream side, according to 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.

[0141] 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 among the coil layers 120, whereby the coil 110 can be arranged with a compact size in the axis O direction at high density.

[0142] When 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, the amount of magnetic flux voids is large, and thus the motor efficiency is degraded. 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, the motor efficiency can be improved.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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 point. Thus, the contribution of the permanent magnet 140 to the torque can be maximized, thereby improving the torque of the conical motor 90.

[0147] The electromagnetic force to the outside in the radial direction and 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.

[0148] 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 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.

[0149] 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.

[0150] 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>

[0151] 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.

[0152] 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. However, the present invention is not limited to this. Specifically, it is sufficient to provide the same number of motors as the number of a plurality of propellers to correspond to the respective propellers. The motors may each be of a tubular type or a conical type.

[0153] When the plurality of motors consists of three or more motors arranged side by side in the axis O direction, the arrangement structure may be such that the average motor diameter decreases toward the downstream side. In other words, any arrangement structure can be used as long as the motor positioned more downstream is shifted to the inner side in the radial direction.

[0154] The outer diameter of the upstream-side end portion of the rotor of the downstream-side motor may be larger than the outer diameter of the downstream-side end portion of the rotor of the upstream-side motor. Even in this case, it is sufficient for the average outer diameter of the rotor of the downstream-side motor to be smaller than the average outer diameter of the rotor of the upstream-side motor. Even with this configuration, an arrangement structure can be achieved in which the motor-side motor on the inside is displaced more radially than the motor on the upstream-side motor.

[0155] The inner diameter of the upstream-side end portion of the stator of the downstream-side motor may be larger than the inner diameter of the downstream-side end portion of the stator of the upstream-side motor. Even in this case, it is sufficient for the average inner diameter of the stator of the downstream-side motor to be smaller than the average inner diameter of the stator of the upstream-side motor. Even with this configuration, an arrangement structure can be achieved in which the motor-side motor on the inner side is displaced more radially than the motor on the upstream side.

[0156] The diameter (inner diameter, outer diameter) of the upstream side end portion of the motor on the downstream side may be larger than the diameter (inner diameter, outer diameter) of the downstream side end portion of the motor on the upstream side. Even in this case, it is sufficient if the average diameter (average inner diameter, average outer diameter) of the downstream side motor is smaller than the average diameter (average inner diameter, average outer diameter) of the upstream side motor. Even with this configuration, an arrangement structure can be achieved in which the motor on the inner side is displaced more in the radial direction than the motor on the upstream side.

[0157] 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.

[0158] The shell 50 can have any shape as long as the shell inner surface 51 has a diameter that decreases toward the downstream side. In other words, the shape of the shell outer surface 52 does not need to have a diameter that decreases toward the downstream side.

[0159] In the embodiment, an example is described in which the shell 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 shell 50 is divided in the axis O direction with the outer peripheral ring 30 of the propeller and the motor interposed therebetween may be adopted. Furthermore, a configuration in which the shell 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.

[0160] 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.

[0161] 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.

[0162] 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, operating effects like those in the embodiment can be obtained.

[0163] 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 thereto, and for example, the fluid machine can be applied to the thruster 8 of a ship or the like that travels on water.

[0164] 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

[0165] The thruster (fluid machine) 8 and the underwater vehicle 1 described in the individual embodiments are configured, for example, as follows. (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 an inner surface with 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 being 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;a motor provided to correspond to the propeller, and a rotor having an annular shape fixed to an outer peripheral portion of the propeller and housed in the shell 50, and including a stator having an annular shape surrounding the rotor and fixed in the shell 50, in which a plurality of the propellers are provided to be spaced apart from each other in the axis O direction, the motors are provided in the same number as the propellers to correspond to each of the propellers, and of a plurality of motors, the rotor of the motor positioned more on the downstream side has an averagely smaller outer diameter;

[0166] With the configuration described above, the inner surface of the shell 50 has the diameter decreasing toward the downstream side, and the flow path cross-sectional area of ​​the flow path on the inner side decreases toward the downstream side, whereby the pumping efficiency of a fluid can be improved.

[0167] Since the inner surface of the shell 50 has a diameter that decreases toward the downstream side, the average outer diameter of the rotors of the plurality of motors decreases toward the downstream side. Thus, an arrangement structure is obtained in which the motor on the downstream side is shifted more toward the inside in the radial direction.

[0168] When a plurality of motors have the same average outer diameter, the motors are arranged side by side, with their radial position being the same with respect to the shape of the inner surface of the shell 50 as the diameter decreases. In this case, due to the conflict between the shape of the shell 50 and the arrangement structure of the plurality of motors, the shell 50 must conform to the arrangement structure of the motors, resulting in an increase in the size of the shell 50.

[0169] In view of this, in the present aspect, as described above, the arrangement structure on the downstream side has the motor on the inner side further shifted in the radial direction, so that the arrangement structure with the decreasing diameter conforms to the shape of the shell 50. Thus, the shape of the shell 50 does not need to be enlarged to adapt to the arrangement of the motors, whereby a compact configuration can be achieved. (2) A fluid machine according to a second aspect is the fluid machine according to (1), in which, of adjacent motors in the axial direction, an inner diameter of the stator of the motor positioned on the downstream side is smaller than an average inner diameter of the stator of the motor positioned on the upstream side, and an average outer diameter of the rotor of the motor positioned on the downstream side is smaller than an average outer diameter of the rotor of the motor positioned on the upstream side.

[0170] As a result, the inner diameter and outer diameter of a motor group including multiple motors correspond to the shape of the shell 50 with the decreasing diameter. Thus, the shell 50 can be manufactured more compactly. (3) A fluid machine according to a third aspect is the fluid machine according to (1) or (2), in which the shell 50 has a cross-sectional shape perpendicular to the axis O, having a blade shape with an upstream side end portion corresponding to a leading edge and a downstream side end portion corresponding to a trailing edge.

[0171] The cross-sectional shape of the shell 50 has a vane shape, which can minimize resistance due to water flow when the fluid machine is arranged underwater. A shape that conforms to the flow direction of the fluid pumped by the propeller is achieved, whereby pumping efficiency can be further improved. On the other hand, in order to maintain the vane shape while accommodating the plurality of motors within the plurality of motors, the shape of the shell 50 must be enlarged more than necessary to conform to the arrangement structure of the plurality of motors. In view of this, in the present aspect, the arrangement structure of the plurality of motors conforms to the shape of the shell 50, whereby the size of the shell 50 can be reduced. (4) A fluid machine according to a fourth aspect is the fluid machine according to any one of (1) to (3), in which two of the propellers are provided in the axial direction, the two propellers having opposite rotation directions to each other, each of the propellers including a plurality of circumferentially arranged moving blades, a suction-side pressure distribution of the moving blade of the propeller on the downstream side being of a leading edge load type with a load concentrated on a leading edge, and a suction-side pressure distribution of the moving blade of the propeller on the upstream side being of a balanced load type with a load more distributed in the axial O direction than in the suction-side pressure distribution of the moving blade on the downstream side, a load on an inner side in the radial direction being smaller.

[0172] Here, the fluid resistance between the upstream-side moving blade and the shaft section 3 tends to increase due to pressure disturbance in water suction. 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 of a balanced load type, and thus an increase in fluid resistance due to pressure disturbance can be minimized. On the other hand, the suction-side pressure distribution of the downstream-side moving blade is of a leading edge load type in which the load is concentrated on the leading edge, so propeller efficiency can be improved. (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 attached to the shaft portion 3 and facing the upstream side of the inner peripheral ring 11 entirely over a circumferential direction; and a stay 78 supporting the shell 50 relative to the shaft portion 3.

[0173] 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. (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 divided into a plurality of parts in the axis O direction, and the fluid machine further includes a coupling portion 70 that couples the plurality of segments in the axis O direction.

[0174] By decoupling the coupling section 70, the shell 50 can be separated into a plurality of segments. This allows the rotor and stator of the motors to be mounted in the shell 50. (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 shell 50, and a cross-sectional shape along the outer surface of the shell 50 has a blade shape, the upstream side being a leading edge and the downstream side being a trailing edge.

[0175] Thus, resistance due to the coupling portion 70 can be suppressed when water flows on the outer surface of the shell 50. (8) A fluid machine according to an eighth aspect is the fluid machine according to any one of (1) to (7), in which at least one of the plurality of motors is a conical motor 90 in which the rotor and the stator have a diameter that decreases from the upstream side to the downstream side.

[0176] By using the conical motor 90 with the rotor and stator having a diameter that decreases toward the downstream side like the motor, the shape of each motor can correspond to the shape of the shell 50. 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. (9) A fluid machine according to a ninth aspect is the fluid machine according to (8), in which the stator includes: a stator core 101 including 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 projecting from an inner surface of the back yoke 104 toward the inside in the radial direction, extending in a circumferential direction entirely across the axis O direction, and having a thickness in the circumferential direction that decreases with a decreasing diameter toward the downstream side; and a plurality of coils 110 provided to surround an outer surface of each of the teeth 106.

[0177] 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. (10) A fluid machine according to a tenth aspect is the fluid machine according to (9), 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.

[0178] 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. (11) A fluid machine according to an eleventh aspect is the fluid machine according to (10), in which each layer of the spool 110 is inclined toward the inside in the radial direction toward the downstream side. As a result, the spool 110 can be efficiently arranged, which extends toward the inside in the radial direction toward the downstream side with respect to the teeth 106. (12) A fluid machine according to a twelfth aspect is the fluid machine according to (11), in which the spool 110 has axis O direction positions of an end portion of a spool end 111 in the axis O corresponding to each other in each layer.

[0179] 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. (13) A fluid machine according to a thirteenth aspect is the fluid machine according to (12), in which a portion of each layer of the coil 110 forming the coil end 111 is bent parallel to the axis O.

[0180] 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. (14) A fluid machine according to a fourteenth aspect is the fluid machine according to any one of (8) to (13), 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 entirely across the axis O direction, and the permanent magnets 140 extend to be inclined to an inner side in the radial direction toward the downstream side and have a width in the circumferential direction that decreases toward the downstream side.

[0181] 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. (15) A fluid machine according to a fifteenth aspect is the fluid machine according to (14), in which a magnetization direction of the permanent magnets 140 is perpendicular to an outer surface of the rotor.

[0182] 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. (16) A fluid machine according to a sixteenth aspect is the fluid machine according to (14) or (15), 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 retainer plate in contact with end portions of the outer peripheral ring 30 and the rotor core 131 on the downstream side; and a retainer bolt 151 provided through the retainer plate in the axis O direction and fixing the retainer plate to the outer peripheral ring 30.

[0183] 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. (17) A fluid machine according to a seventeenth aspect is the fluid machine according to (16), 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.

[0184] 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 accommodates 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.

[0185] 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.

[0186] 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. (18) An underwater vehicle 1 according to an eighteenth aspect includes: a vehicle body 2; and thrust apparatus 8 provided on the vehicle body 2, wherein the thrust apparatus 8 is the fluid machine described in any one of (1) to (17).

[0187] With such an underwater vehicle 1, the propulsion device 8 can be made compact while the thrust efficiency is improved. 1 underwater vehicle 2 vehicle body 3 shaft section 3a Shaft outer surface 5 Recording groove 5a Groove bottom surface 5b Groove upstream side surface 5c Groove downstream side 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 circumferential flow path surface 20A First blade (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 covers 50A First Cavity 50B Second cavity 51 Shell inner surface 52 Shell outer surface 53 Front edge of the cover 54 Rear edge of the shell 56 Cylindrical fixation 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 anterior margin 70b Protruding section of the posterior margin 71 Upstream projecting section 71a Bolt fixing hole 72 Above 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 motor (motor) 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 teeth 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 Magnet upstream surface 145 Magnet downstream surface 150 Second retaining plate 150a bolt stop hole 151 retaining bolts O axis R1 Average outer diameter of the motor rotor on the upstream side R2 Average outer diameter of the rotor of the motor on the downstream side< / betriebseffekte> < / spulen> < / statorkern> < / rohrmotor> < / streben> < / kopplungsabschnitt> < / lagerabschnitte> < / innenumfangsring> < / schachtabschnitt> < / schubapparat>

Claims

[1] Fluid machine (8), comprising: a shaft section (3) extending in an axial direction; a shell (50) provided to surround the shaft portion and having a shell inner surface (51) with a diameter decreasing axially from an upstream side on one side to a downstream side on another side, a flow path being formed between the shell and the shaft portion and having a flow path cross-sectional area decreasing toward the downstream side, a plurality of propellers (10A, 10B) rotatably provided about an axis (O) between the well portion and the shell and configured to pump a fluid from the upstream side toward the downstream side; and a like plurality of motors (80, 90) associated with the respective propellers and each including a rotor (82, 130) having an annular shape, fixed to an outer peripheral portion of the propeller and housed in the shell, and having a Stator (81, 100) having an annular shape surrounding the rotor (82, 130) and fixed in the shell, wherein the propellers are spaced apart from each other in the axial direction, and the rotor of the motor positioned furthest downstream has a smaller average outer diameter, the fluid machine characterized by is that the shell includes a plurality of longitudinal sections (61, 62, 64) which are divided axially into a plurality of parts, the fluid machine further includes a coupling portion (70) coupling the plurality of segments in the axial direction, the coupling portion has a convex curved shape protruding from an outer surface of the shell, and the cross-section along the outer surface of the shell of the coupling section represents a symmetrical airfoil, the upstream side being a leading edge and the downstream side being a trailing edge. [2] Fluid machine (8) according to claim 1, wherein of the motors adjacent to each other in the axial direction, an average inner diameter of the stator of the motor positioned on the downstream side is smaller than an average inner diameter of the stator of the motor positioned on the upstream side, and an average outer diameter of the rotor of the motor positioned on the downstream side is smaller than an average outer diameter of the rotor of the motor positioned on the upstream side. [3] The fluid machine (8) according to claim 1 or 2, wherein the cross section of the shell passing through the axis has a blade shape having 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. [4] Fluid machine (8) according to one of claims 1 to 3, wherein exactly two of the propellers are provided in the axial direction, the two propellers rotate in opposite directions to each other, 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 of a leading edge load type with a load concentrated on a leading edge, and a suction-side pressure distribution of the rotor blade (20A) of the propeller (10A) on the upstream side is of a balanced load type, with a load more distributed in the axial direction than in the suction-side pressure distribution of the rotor blade on the downstream side, a load on an inner side being smaller in the radial direction. [5] Fluid machine (8) according to one of claims 1 to 4, wherein each propeller includes an inner peripheral ring (11) attached to an outer peripheral side of the shaft section via a clearance, and the fluid machine further includes: a thrust bearing (42, 43) fixed to the shaft portion (3) and facing the upstream side of the inner circumferential ring entirely over a circumferential direction; and a strut (78) supporting the shell relative to the shaft section. [6] Fluid machine (8), comprising: a shaft section (3) extending in an axial direction; a shell (50) provided to surround the shaft portion and having a shell inner surface (51) with a diameter decreasing axially from an upstream side on one side to a downstream side on another side, a flow path being formed between the shell and the shaft portion and having a flow path cross-sectional area decreasing toward the downstream side, a plurality of propellers (10A, 10B) rotatably provided about an axis (O) between the well portion and the shell and configured to pump a fluid from the upstream side toward the downstream side; and a like plurality of motors (80, 90) associated with the respective propellers, each including a rotor (82, 130) having an annular shape fixed to an outer peripheral portion of the propeller and housed in the shell, and a stator (81, 100) having an annular shape surrounding the rotor (82, 130) and fixed in the shell, wherein the propellers are spaced apart from each other in the axial direction, and the rotor of the motor positioned furthest downstream has a smaller average outer diameter, the fluid machine characterized by is that at least one of the plurality of motors is a conical motor (90) in which the rotor and the stator have a diameter that decreases from the upstream side to the downstream side. 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 quadruple number 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 entirely over the axial direction, and having a thickness in the circumferential direction decreasing with a decreasing diameter decreasing toward the downstream side; and a plurality of coils (110) provided to surround an outer surface of each of the teeth. [7] Fluid machine (8) according to claim 6, wherein each of the coils includes a rectangular copper wire having a flat shape with a plurality of layers stacked radially 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. [8] The fluid machine (8) according to claim 7, wherein each layer of the coil is inclined toward the inside in the radial direction toward the downstream side. [9] The fluid machine (8) according to claim 8, wherein the coil has axial direction positions of an end portion of a coil end (111) in the axial direction corresponding to each other in each layer. [10] The fluid machine (8) according to claim 9, wherein a portion of each layer of the coil forming the coil end (111) is bent parallel to the axis. [11] Fluid machine (8), comprising: a shaft section (3) extending in an axial direction; a shell (50) provided to surround the shaft portion and having a shell inner surface (51) with a diameter decreasing axially from an upstream side on one side to a downstream side on another side, a flow path being formed between the shell and the shaft portion and having a flow path cross-sectional area decreasing toward the downstream side, a plurality of propellers (10A, 10B) rotatably provided about an axis (O) between the well portion and the shell and configured to pump a fluid from the upstream side toward the downstream side; and a like plurality of motors (80, 90) associated with the respective propellers, each including a rotor (82, 130) having an annular shape fixed to an outer peripheral portion of the propeller and housed in the shell, and a stator (81, 100) having an annular shape surrounding the rotor (82, 130) and fixed in the shell, wherein the propellers are spaced apart from each other in the axial direction, and the rotor of the motor positioned furthest downstream has a smaller average outer diameter, the fluid machine characterized by is that at least one of the plurality of motors is a conical motor (90) in which the rotor and the stator have a diameter that decreases from the upstream side to the downstream side, 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 completely across the axial direction, and the permanent magnets extend to be inclined to an inner side in the radial direction towards the downstream side and have a width in the circumferential direction which decreases towards the downstream side, 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 circumferential 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 through the retaining plate in the axial direction and fixing the retaining plate to the outer peripheral ring. [12] Fluid machine (8) according to claim 11, wherein a magnetization direction of the permanent magnets is perpendicular to an outer surface of the rotor. [13] Fluid machine (8) according to claim 11 or 12, 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. [14] Underwater vehicle (1), comprising: a vehicle body (2); and a thrust apparatus (8) provided on the vehicle body, the thrust apparatus being the fluid machine (8) described in any one of claims 1 to 13.

Images