Fluid machine for underwater vehicle and underwater vehicle

Patent metadata

Field	Value
Publication number	US-12286201-B2
Application number	US-202217700724-A
Country	US
Kind code	B2
Filing date	Mar 22, 2022
Priority date	Mar 31, 2021
Publication date	Apr 29, 2025
Grant date	Apr 29, 2025

Abstract

A fluid machine includes: a shaft portion; a shroud having an inside surface with a diameter decreasing from an upstream side toward a downstream side, a flow path being formed between the shroud and the shaft portion and having a flow path cross-sectional area decreasing toward the downstream side; a propeller rotatably provided about an axis between the shaft portion and the shroud and configured to pump a fluid from the upstream side toward the downstream side; and a motor provided to correspond to the propeller and including a rotor having a ring-like shape fixed to an outer circumference portion of the propeller and accommodated in the shroud and a stator having a ring-like shape surrounding the rotor and fixed in the shroud, in which a plurality of the propellers are provided to be spaced apart in the axis direction, the motors are provided in an identical number to 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 a smaller average outside diameter.

First claim

The invention claimed is:

1. A fluid machine for an underwater vehicle comprising:
a shaft portion extending in an axis direction;
a shroud provided to surround the shaft portion and having an inside surface with a diameter decreasing from an upstream side on one side in the axis direction toward a downstream side on another side in the axis direction, a flow path being formed between the shroud and the shaft portion and having a flow path cross-sectional area decreasing toward the downstream side;
a plurality of propellers rotatably provided about an axis between the shaft portion and the shroud and configured to pump a fluid from the upstream side toward the downstream side; and
a plurality of motors provided to correspond to the propellers, respectively, each motor including a rotor having a ring shape fixed to an outer circumference portion of a corresponding one of the propellers and accommodated in the shroud and a stator having a ring shape surrounding the rotor and fixed in the shroud, wherein
the plurality of propellers are spaced apart in the axis direction,
the plurality of motors are provided in an identical number to that of the plurality of propellers,
the plurality of motors include a conical motor and a tubular motor, and
an average outside diameter of the rotor of the conical motor is smaller than an average outside diameter of the rotor of the tubular motor.

2. The fluid machine according to claim 1 , wherein,
of the plurality of motors, the conical motor and the tubular motor are adjacent to each other in the axis direction, an average inside diameter of the stator of the conical motor is smaller than an average inside diameter of the stator of the tubular motor, and the conical motor is positioned downstream of the tubular motor.

3. The fluid machine according to claim 1 , wherein the shroud has a cross-sectional shape, orthogonal to the axis, of a blade form with an end portion on the upstream side corresponding to a leading edge and an end portion on the downstream side corresponding to a trailing edge.

4. The fluid machine according to claim 1 , wherein
the plurality of propellers includes a first propeller and a second propeller provided in the axis direction, wherein the second propeller is arranged downstream of the first propeller,
the first and second propellers have respective rotational directions opposite to each other,
each of the first and second propellers includes a plurality of blades arranged in a circumferential direction,
a suction side pressure distribution of each blade of the second propeller has a load concentrated on a leading edge, and
for each blade of the first propeller, a suction side pressure distribution has a load balanced, with a load more distributed in the axis direction than in the suction side pressure distribution of the blade, and with a load being smaller on an inner side of the blade in a radial direction.

5. The fluid machine according to claim 1 , wherein
each propeller includes an inner circumference ring fitted to an outer circumference side of the shaft portion across a clearance, and
the fluid machine further includes:
a thrust bearing fixed to the shaft portion and facing the upstream side of the inner circumference ring entirely over a circumferential direction; and
a strut supporting the shroud relative to the shaft portion.

6. The fluid machine according to claim 1 , wherein
the shroud includes a plurality of segments split into a plurality of pieces in the axis direction, and
the fluid machine further includes a coupling portion coupling the plurality of segments in the axis direction.

7. The fluid machine according to claim 6 , wherein
the coupling portion has a convex curved shape protruding from an outside surface of the shroud, and
a cross-sectional shape along the outside surface of the shroud is of a blade form with an upstream side of the cross-sectional shape being a leading edge and a downstream side of the cross-sectional shape being a trailing edge.

8. The fluid machine according to claim 1 , wherein the rotor and the stator of the conical motor have a diameter decreasing from the upstream side toward the downstream side.

9. The fluid machine according to claim 8 , wherein the stator of the conical motor includes:
a stator core including
a back yoke forming an annular shape around the axis and having a diameter decreasing toward the downstream side, and
a plurality of teeth protruding from an inside surface of the back yoke toward an inner side in a radial direction, extending in a circumferential direction entirely over the axis direction, and having a thickness in the circumferential direction decreasing, with a diameter decreasing, toward the downstream side; and

a plurality of coils provided to respectively surround an outer surface of each of the teeth.

10. The fluid machine according to claim 9 , wherein
each coil includes a rectangular copper wire having a flat shape with a plurality of layers stacked in the radial direction around a corresponding one of the teeth, and
for each coil, each layer of the coil has a rectangular shape with a distance in the circumferential direction decreasing toward the downstream side, as viewed in the radial direction.

11. The fluid machine according to claim 10 , wherein for each coil, each layer of the coil is inclined to the inner side in the radial direction toward the downstream side.

12. The fluid machine according to claim 11 , wherein for each coil, each layer of the coil has a coil end portion, and wherein each coil end portion ends at a same position with respect to the axis direction.

13. The fluid machine according to claim 12 , wherein for each coil, each coil end portion is bent so as to be parallel to the axis.

14. The fluid machine according to claim 8 , wherein
the rotor of the conical motor includes:
a rotor core forming an annular shape around the axis and having a diameter decreasing toward the downstream side; and
a plurality of permanent magnets provided at an interval from the rotor core in a circumferential direction and extending entirely over the axis direction, and
wherein the permanent magnets extend and are inclined to an inner side in a radial direction toward the downstream side and have a width in the circumferential direction decreasing toward the downstream side.

15. The fluid machine according to claim 14 , wherein a magnetization direction of the permanent magnets is orthogonal to an outside surface of the rotor of the conical motor.

16. The fluid machine according to claim 14 , wherein
each propeller further includes an outer circumference ring having a ring shape forming the outer circumference portion of the propeller,
the rotor core of the conical motor is fitted to an outside surface of the outer circumference ring of the corresponding one of the propellers, and
the fluid machine further includes:
a holding plate that is in contact with a downstream side end of the rotor core of the conical motor and a downstream side end of the outer circumference ring of the corresponding one of the propellers; and
a holding bolt provided through the holding plate in the axis direction and fixing the holding plate to the outer circumference ring of the corresponding one of the propellers.

17. The fluid machine according to claim 16 , wherein
the outer circumference ring of each propeller has a thickness in the radial direction decreasing toward the downstream side, and
a notched portion is formed in a portion between adjacent ones of the permanent magnets at an end portion

Assignees

• Mitsubishi Heavy Ind Ltd

Inventors

• Senoo Shigeki
• Isobe Shinichi
• Yamada Wataru
• Nishida Takehiko
• Yamada Takuyoshi
• Hosono Kazuki
• Noda Yoshitomo
• Takeda Hiroki
• Sekine Yuichi

Classifications

• B63H21/17 Primary

  by electric motor · CPC title

• B63G8/08

  Propulsion ({schnorkels B63G8/36;} nuclear propulsion B63H21/18; submerged exhausting apparatus F01N13/12) · CPC title

• B63H5/14

  characterised by being mounted in non-rotating ducts or rings, e.g. adjustable for steering purpose (shrouding ring attached to blades B63H1/16; jet propulsion B63H11/00) · CPC title

• B63H1/28 Primary

  Other means for improving propeller efficiency · CPC title