JP7144001B2 - propulsion device - Google Patents

Description

The present invention relates to propulsion devices for use in fluids.

Conventionally, in ships and the like, screws and the like have been used as propulsion devices used in fluids. A screw rotates in a fluid to generate propulsion in the direction of its axis of rotation. Generally, it consists of a boss that serves as the axis of rotation and multiple blades that generate propulsion from the rotation transmitted from the boss. ing.

Propulsion systems using such screws are known to suffer from cavitation problems. Cavitation refers to the generation of air bubbles in a fluid as the fluid drops below the saturated water vapor pressure. In particular, in conventional marine propellers, tip vortex cavitation is known, which is cavitation caused by free vortices emitted from the ends of the blades and a drop in pressure at the center of the vortices. When cavitation occurs, it reduces the propulsion force of the ship, or damages the blade surface by causing air bubbles to collide with the blade surface.

Various propulsion devices have been developed as techniques for eliminating such cavitation. For example, the propulsion device described in Patent Document 1 sucks a fluid into a rotationally driven rotary base, causes the sucked fluid to flow along a flow path provided in the rotary base, and applies a centrifugal force to the fluid. configured to accelerate. This propulsion device generates a propulsion force from a reaction force generated when fluid is discharged from a rotating base.
Further, the propulsion device described in Patent Document 2 also generates a propulsion force from the reaction force generated when the fluid is discharged from the rotating body.

WO2015115072 JP 2014-196099 A Japanese Patent Publication No. 2015-525320

The propulsion devices described in Patent Literatures 1 and 2 are configured such that negative pressure is less likely to occur on the contact surface between the components of the propulsion device and the fluid, and cavitation is less likely to occur. Further, although Patent Document 3 does not mention cavitation, it is believed that the propulsion device described in Patent Document 3 has a structure in which cavitation is less likely to occur.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a propulsion device that generates a higher propulsive force than the propulsion devices disclosed in Patent Documents 1 to 3 while suppressing the occurrence of cavitation.

Hereinafter, in this section, the term "invention" refers to the invention described in the scope of claims.
The first invention is
A propulsion device that sucks a fluid from the suction side and discharges it from the discharge side,
a screw having a plurality of blades arranged helically about the axis of rotation;
a tubular housing having the plurality of blades fixed to its inner side surface and having recesses in the direction of the rotation axis at the suction side edge and between adjacent blades;
It is a propulsion device having

The second invention is
In the tubular housing, a first radius from the rotation axis to the inner side surface on the discharge side is smaller than a second radius from the rotation axis to the inner side surface on the suction side.
It is a propulsion device according to the first invention.

The third invention is
A propulsion device that sucks a fluid from the suction side and discharges it from the discharge side,
a screw having a plurality of blades arranged helically about the axis of rotation;
The plurality of blades are fixed to an inner side surface, and a first radius from the rotation axis to the inner side surface on the discharge side is larger than a second radius from the rotation axis to the inner side surface on the suction side. , a tubular housing, and
a propulsion device having a
The term "helical" means that the blades are arranged at an angle to the axis of rotation, and not all portions of the blades need to be inclined.
"Fixed" may be a state in which the blade and tubular housing are connected. That is, the blades and tubular housing do not necessarily have to be separate components, and the blades and tubular housing may be integrally molded members.

The fourth invention is
The tubular housing has a recess in the direction of the axis of rotation at the suction-side edge and between adjacent blades.
It is a propulsion device according to the third invention.

The fifth invention is
further comprising a casing that rotatably accommodates the tubular housing;
A propulsion device according to the first to fourth inventions.

The sixth invention is
The casing has a rectifying projection that is disposed opposite to the discharge side of the tubular housing and that protrudes tapered toward the discharge side.
It is a propulsion device according to the fifth aspect of the invention.

The seventh invention is
The screw has an axial projection on the rotation axis of the screw and on the discharge side,
The rectifying projection has a bearing that rotatably supports the shaft-shaped projection,
It is a propulsion device according to the sixth invention.

According to the propulsion device of the present invention, it is possible to generate a higher propulsive force than a conventional propulsion device using a screw while suppressing the occurrence of cavitation.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view of the propulsion apparatus of Embodiment 1 of this invention. 1 is a front view of a propulsion device according to Embodiment 1 of the present invention; 1 is a rear view of a propulsion device according to Embodiment 1 of the present invention; BRIEF DESCRIPTION OF THE DRAWINGS The side view of the propulsion apparatus of Embodiment 1 of this invention. FIG. 2 is an enlarged view of a recess provided in the tubular housing of the propulsion device according to Embodiment 1 of the present invention; Measurement results using a conventional screw Measurement results using the propulsion device of Embodiment 1 of the present invention Measurement results using the propulsion device of Embodiment 1 of the present invention The figure which shows the propulsion apparatus of the modification 1 of Embodiment 1 of this invention. Measurement results using the propulsion device of Modification 1 of Embodiment 1 of the present invention The figure which shows the propulsion apparatus of the modification 2 of Embodiment 1 of this invention. The perspective view of the propulsion apparatus of Embodiment 2 of this invention. The front view of the propulsion apparatus of Embodiment 2 of this invention The rear view of the propulsion device of Embodiment 2 of this invention The side view of the propulsion apparatus of Embodiment 2 of this invention The perspective view of the propulsion apparatus in Embodiment 3 of this invention. The front view of the propulsion apparatus in Embodiment 3 of this invention The rear view of the propulsion device in Embodiment 3 of this invention The side view of the propulsion apparatus in Embodiment 3 of this invention Measurement results using the propulsion device of Embodiment 3 of the present invention The perspective view of the propulsion apparatus of the modification 1 of Embodiment 3 of this invention. The front view of the propulsion apparatus of the modification 1 of Embodiment 3 of this invention. The rear view of the propulsion apparatus of the modification 1 of Embodiment 3 of this invention. The side view of the propulsion apparatus of the modification 1 of Embodiment 3 of this invention. The figure which shows the propulsion apparatus of the modification 1 of Embodiment 3 of this invention. The perspective view of the propulsion apparatus of the modification 2 of Embodiment 3 of this invention. The front view of the propulsion apparatus of the modification 2 of Embodiment 3 of this invention. The rear view of the propulsion apparatus of the modification 2 of Embodiment 3 of this invention. The side view of the propulsion apparatus of the modification 2 of Embodiment 3 of this invention. The figure which shows the propulsion apparatus of the modification 2 of Embodiment 3 of this invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.
It should be noted that the present invention means the invention described in the scope of claims or the section of Means for Solving the Problems, and is not limited to the following embodiments. In addition, at least the words and phrases in angle brackets mean the words and phrases described in the claims or the means for solving the problems section, and are not limited to the following embodiments.
Structures and methods described in dependent claims, structures and methods of embodiments corresponding to structures and methods described in dependent claims, and structures and methods described only in embodiments without claims are optional configurations and methods in the present invention. In the sense that the configuration and method described in the embodiment when the description of the claims is broader than the description of the embodiment are also examples of the configuration and method of the present invention, in the present invention, any configuration and method be. In either case, the essential features and methods of the invention are described in the independent claims.
The effects described in the embodiments are the effects when having the configuration of the embodiment as an example of the present invention, and are not necessarily the effects of the present invention.
When there are multiple embodiments, the configuration disclosed in each embodiment is not limited to each embodiment, but can be combined across the embodiments. For example, a configuration disclosed in one embodiment may be combined with another embodiment. In addition, the configurations disclosed in each of a plurality of embodiments may be collected and combined.
The problems described in the Problems to be Solved by the Invention are not known problems, but were independently discovered by the inventors, and are facts that affirm the inventive step of the invention together with the structure and method of the present invention.

(Embodiment 1)
Embodiment 1 of the present invention will be described below with reference to FIGS. 1 to 4. FIG. 1 is a perspective view of the propulsion device 10 of Embodiment 1, FIG. 2 is a front view of the propulsion device 10, FIG. 3 is a rear view of the propulsion device 10, and FIG. 4 is a side view of the propulsion device 10. ing.
Here, the propulsion device 10 obtains propulsive force by sucking fluid from the fluid intake side on the right side of FIG. 1 and discharging the fluid from the fluid discharge side on the left side of FIG.

The propulsion device 10 comprises a screw portion 100 and a tubular housing 101 . The screw portion 100 has a boss 102 , a plurality of blades 103 and straightening projections 104 . A drive shaft 105 for transmitting the rotational force of a motor or the like to the propulsion device 10 is attached to the fluid intake side of the propulsion device 10 shown in FIGS.

Boss 102 functions as a rotation shaft of screw portion 100 . A drive shaft 105 is attached to the fluid intake side of the boss 102 and receives a rotational force generated by a motor (not shown) or the like via the drive shaft 105 .
Although the boss 102 shown in the drawings has a cylindrical shape, it has a shape such that the cross section increases from the fluid suction side toward the fluid discharge side, for example, like the bosses described in Embodiments 3 and 4, which will be described later. It may have a conical shape.

Three blades 103 are attached to the side surface of the boss 102 and arranged spirally with respect to the rotation axis direction of the boss 102 . The blade 103 is a part that rotates together with the boss 102 to generate lift in the direction of the rotation axis, like blades provided in a conventional screw propeller, thereby generating thrust in the propulsion device 10 .

The blade 103 is twisted from the fluid suction side toward the fluid discharge side. That is, assuming that the edge of the blade 103 attached to the boss 102 is the inner edge 106 and the edge of the blade 103 located on the opposite side of the inner edge is the outer edge 107, as shown in FIG. The attachment angle α of the inner edge portion 106 with respect to the direction and the inclination angle β of the outer edge portion 107 with respect to the rotation axis direction of the boss 102 are different, and the angle β of the outer edge portion 107 is larger than the angle α of the inner edge portion 106. is formed in

In this specification, the configuration in which the screw portion 100 has three blades 103 is illustrated and described, but the number of blades may be any number.

At the end of the boss 102 on the fluid discharge side, there is provided a conical rectifying projection 104 that protrudes tapered toward the discharge side. The rectifying protrusion 104 rectifies the fluid discharged from the fluid discharge side around the rotating shaft of the screw portion 100 . However, the rectifying protrusion is not an essential component and may be omitted.

A tubular housing 101 is arranged around the screw portion 100, and the outer edges 107 of three blades 103 are fixed to its inner side surface. In the configuration shown in FIGS. 1 to 4, the inner side surface has the outer edge 107 of the blade 103 fixed over its entire length. However, it is sufficient that the outer edge 107 of the blade 103 is fixed to the inner side surface of the tubular housing 101 so that the tubular housing 101 and the blade 103 can rotate together, and only a part of the outer edge 107 of the blade 103 is attached to the inner side surface. It may be a fixed configuration.

Also, after the screw portion 100 and the tubular housing 101 are formed as separate components, the screw portion 100 can be fixed to the inner side surface of the tubular housing 101 by welding or the like. However, as described above, the screw portion 100 and the tubular housing 101 only need to be fixed so as to be integrally rotatable. For example, the screw portion 100 and the tubular housing 101 may be integrally formed by casting or the like.

Tubular housing 101 has a circular cross-section perpendicular to the axis of rotation of screw portion 100 . The circular cross section on the fluid discharge side has a radius r ₁₁ (“first radius” in the present invention) from the rotation axis to the inner side surface, and the circular cross section on the fluid suction side has a radius r ₁₂ from the rotation axis to the inner side surface. ("second radius" in the present invention), and the radius r11 _on the fluid discharge side is configured to be smaller than the radius r12 _on the fluid suction side.

Furthermore, the tubular housing 101 has a recess 108 located on the suction side edge and between two adjacent blades 103 . FIG. 5 shows an enlarged view of recess 108 . As shown in FIG. 5, the recess 108 is such that the distance x1 from the edge of the fluid discharge _side of the tubular housing 101 to the bottom of the recess 108 is from the edge of the fluid discharge side of the tubular housing 101 to the edge of the fluid suction side. , _i.e. , in the direction of the rotation axis. 1 to 3, the configuration of the recess 108 is omitted.

The recesses 108 are intended to facilitate the flow of fluid into the tubular housing 101 in order to increase the thrust of the propulsion device of the present invention. In the embodiment shown in FIG. 5, the recess 108 has a generally semi-elliptical shape, and furthermore, the recess 108 extends from the fluid intake edge of the tubular housing 101 so that more fluid is drawn around the blades 103 . The slope to the bottom is steeper on the proximal side of blade 103 than on the distal side of blade 103 . However, the shape of the recess 108 is not limited to the illustrated shape.
Note that the recess 108 is an arbitrary configuration, and the tubular housing 101 does not have to have the recess 108 .

When a fluid flows through a cylinder, according to Bernoulli's theorem, the flow velocity increases as the cross-sectional area of the cylinder becomes smaller. That is, in the propulsion device 10, the fluid velocity is higher on the fluid discharge side than on the fluid intake side, and the fluid is accelerated in the propulsion device, so that the propulsion device 10 can obtain a high propulsive force.

FIG. 6 shows the measurement results of the thrust obtained by the conventional screw, and FIG. 7 shows the measurement results of the thrust obtained by the propulsion device 10 of the first embodiment. The measured values shown in FIGS. 6 and 7 were obtained by placing a propulsion device with a motor attached to the tip of the drive shaft 105 in water, and measuring the force (hereinafter referred to as tractive force) that causes the propulsion device to move forward when the motor is driven. The power consumption of the motor at that time was measured along with the measurement by a spring gauge. Measurement was performed 15 times for each of the rotation speeds of 600 rpm and 1110 rpm, and the average value was calculated.

FIG. 6 shows the measurement results for a screw with four blades and a radius of 30 mm from the axis of rotation to the outermost edge of the screw blades. In addition, FIG. 7 shows a propellant with a radius r ₁₁ of 30 mm on the fluid discharge side, a radius r ₁₂ of 35 mm on the fluid suction side, four blades, and no rectification protrusions and no dents on the edges on the suction side. 4 shows the measurement results of the device 10. FIG.

Comparing Embodiment 1 with the conventional screw, the tractive force of Embodiment 1 is more than double that of the conventional screw at both 600 rpm and 1110 rpm. On the other hand, the power consumption of the propulsion device 10 during measurement is higher than that of the conventional screw at both rotation speeds of 600 rpm and 1110 rpm. The rate of increase in power consumption is low relative to the rate of increase. Therefore, the propulsion device 10 is more energy efficient than conventional screws.
In other words, the propulsion device 10 provides improved energy efficiency compared to conventional screws, and furthermore, the provision of a tubular housing around the screw prevents cavitation at the ends of the blades. becomes possible.

Furthermore, FIG. 8 shows the configuration of the propulsion device 10 of Embodiment 1 when (a) without the recess 108 and (b) with the recess 108 are measured under the same conditions (rotation speed 575 rpm). It shows the measurement results. Comparing propulsion device 10(a) without recesses with propulsion device 10(b) having recesses, propulsion device 10(b) consumes less power than propulsion device 10(a). About 7% less, plus about 15% more traction.
From the above, it is possible to improve the energy efficiency and the tractive force by providing the recess on the suction side edge of the propulsion device.

(Modification 1)
The propulsion device 10 of Embodiment 1 further has a guide plate on the fluid intake side of the propulsion device 10 so that the fluid flowing around the drive shaft 105 can easily flow into the tubular housing 101 . You may

FIG. 9 shows a propulsion device 10 having a guide plate 109 provided to provide a smooth connection between the edge of the blade 103 on the fluid intake side and the drive shaft 105 . That is, the guide plate 109 functions as a blade in a broad sense together with the blade 103 . When such a guide plate 109 is provided, the fluid can flow into the tubular housing 101 along the guide plate 109 from the fluid intake side.

FIG. 10 shows a case where the number of revolutions is 1110 rpm, the radius r11 on the fluid discharge side is ₃₀ mm, the radius r12 _on the fluid suction side is 35 mm, three blades are provided, and the rectifying projection and the edge on the suction side are recessed. shows the measurement results of the propulsion device 10 with specifications having

Here, the measurement shown in FIG. 6 uses a device having a screw with four blades, whereas the measurement shown in FIG. 10 uses a propulsion device having a screw with three blades. Therefore, it is not possible to simply compare these measurement results, but in general, when the number of blades is small, the propulsive force generated by the rotation of the blades is small, so it is thought that the traction force obtained is small. However, according to the measurement results shown in FIG. 10, the propulsion device of this modified example generates about 1.9 times the tractive force of the conventional screw. Although the power consumption is higher than that of the conventional screw, the rate of increase is about 60%, and the rate of increase in power consumption is lower than the rate of increase in tractive force. That is, according to the propulsion device of this modified example, the energy efficiency is improved.

(Modification 2)
As described above, in the propulsion device 10 shown in FIGS. 1 to 4, a high propulsive force can be obtained by discharging the fluid from the fluid suction side of the propulsion device 10 to the discharge side. However, when the moving speed of a ship or the like to which the propulsion device 10 is attached increases, it is conceivable that the resistance between the fluid around the propulsion device 10 and the tubular housing 101 will increase. To reduce such resistance, the propulsion device 10 may further include a casing 110 outside the tubular housing 101 that rotatably encloses the tubular housing 101 .

FIG. 11 shows a configuration in which a casing 110 is arranged around the propulsion device 10. As shown in FIG. In the example shown in FIG. 11, the casing 110 has a shape that follows the outer shape of the tubular housing 101 of the propulsion device 10, and has a shape such that the radius of the circular cross section decreases from the fluid intake side to the fluid discharge side. It is composed of a front casing 111 and a rear casing 112 connected to the end of the front casing 111 on the fluid discharge side and having a cylindrical shape with the same radius from the fluid intake side to the fluid discharge side. A tubular housing and a screw portion are arranged inside the casing 110, and fixed to the ship bottom or the like by a fixing portion 113 or the like. Fluid flowing in from the fluid intake side of the front casing 111 is sucked into the tubular housing 101 , and fluid discharged from the tubular housing 101 is discharged from the fluid discharge side opening of the rear casing 112 .
It should be noted that the casing 110 only needs to rotatably house the tubular housing 101, and the shape and configuration of the casing 110 are not limited to those shown in FIG. For example, the casing 110 may further include baffles for regulating the flow of fluid passing through the casing 110, or may include baffles or the like as described below.

(Embodiment 2)
In the first embodiment, the tubular housing 101 of the propulsion device 10 has a configuration in which the radius of the circular cross section decreases from the fluid intake side toward the fluid discharge side. Embodiment 2 differs from the configuration of the propulsion device 10 in that the radius of the circular cross section of the tubular housing increases from the fluid intake side to the fluid discharge side. The propulsion device 20 of the second embodiment will be described below, focusing on differences from the first embodiment.

12 is a perspective view of the propulsion device 20 of Embodiment 2, FIG. 13 is a front view of the propulsion device 20, FIG. 14 is a rear view of the propulsion device 20, and FIG. 15 is a side view of the propulsion device 20. there is 1 according to the first embodiment, the propulsion device 20 obtains propulsion by sucking fluid from the fluid intake side on the right side of FIG. 12 and discharging fluid from the fluid discharge side on the left side of FIG.

The tubular housing 201 of the propulsion device 20 has a circular cross section on the fluid discharge side having a radius _r21 from the rotation axis to the inner side surface, and a circular cross section on the fluid intake side having a radius _r22 from the rotation axis to the inner side surface. The radius _r21 on the fluid intake side is configured to be larger than the radius _r22 on the fluid intake side.

Furthermore, as shown in FIG. 15, the tubular housing 201 in this second embodiment has a recess 208 as shown in FIG. optionally have

According to Bernoulli's theorem, when a fluid flows through a cylinder, the flow velocity decreases as the cross-sectional area of the cylinder increases, so the thrust generated by the propulsion device decreases. On the other hand, according to the configuration of the second embodiment, centrifugal force is applied by rotation of the screw 200 and the tubular housing 201, thereby increasing the velocity of the fluid sucked into the propulsion device 10. FIG. Furthermore, since this centrifugal force increases from the fluid intake side toward the fluid discharge side, the fluid flowing inside can also be accelerated from the fluid intake side toward the fluid discharge side. It is possible to increase the propulsive force of the propulsion device 20 by a different principle.

(Embodiment 3)
Embodiments 1 and 2 show configurations in which the radius of the circular cross section differs between the fluid suction side and the fluid discharge side of the tubular housing. In the third embodiment, a configuration in which the radius of the circular cross section of the tubular housing on the fluid suction side and the fluid discharge side is the same will be described.

16 is a perspective view of the propulsion device 30 of Embodiment 3, FIG. 17 is a front view of the propulsion device 30, FIG. 18 is a rear view of the propulsion device 30, and FIG. 19 is a side view of the propulsion device 30. there is As in the first and second embodiments, the propulsion device 30 obtains propulsion by sucking fluid from the fluid intake side on the right side of FIG. 16 and discharging fluid from the fluid discharge side on the left side of FIG.

16 to 19, the tubular housing 301 of the propulsion device 30 has a radius r 31 from the rotation axis to the inner side surface in the circular cross section on the fluid discharge side, and a radius r ₃₁ from the rotation axis to the inner side surface in the circular cross section on the fluid suction side. is configured to be equal to the radius r ₃₂ to .

Also, in the side view shown in FIG. 19, the tubular housing 301 has a recess 308 on the suction side edge and between two adjacent blades, although the recess 308 is an optional configuration. Note that the boss 302 in the third embodiment has a cylindrical shape. Further, although the propulsion device 30 shown in FIG. 16 does not have straightening protrusions, the straightening protrusions may optionally be provided.
Further, the propulsion device 30 may have a casing (not shown) that rotatably accommodates the tubular housing 30 as in the first and second embodiments.

FIG. 20 shows the thrust force measurement results obtained by the propulsion device 30 of the third embodiment, and the tractive force was measured using the same measurement method as in the first embodiment.

Here, measurement results are shown for a propulsion device 30 having tubular housing radii r ₃₁ , r ₃₂ of 30 mm and four blades.

Comparing the measurement results of Embodiment 3 shown in FIG. 20 with the measurement results of the conventional screw shown in FIG. In this case, it is also about 1.5 times greater than the conventional screw. The power consumption of the propulsion device 30 increases by about 68% when the rotation speed is 1110 rpm, but increases by only about 10% when the rotation speed is 600 rpm. That is, in the third embodiment, the energy efficiency is improved especially at low revolutions.

(Modification 1)
In Modification 1, unlike the propulsion device 30 shown in Embodiment 3, the propulsion device is configured such that the cross section of the boss increases radially outward from the fluid suction side toward the fluid discharge side. 40 will be explained. A propulsion device 40 according to Modification 1 is shown in FIGS. 21 to 24 . As is clear from the side view of FIG. 24, the cross-sectional area of the fluid path formed by the tubular housing 401 in the direction perpendicular to the rotation axis decreases from the fluid suction side toward the fluid discharge side. The internal fluid path is formed in a direction away from the rotating shaft from the fluid suction side toward the fluid discharge side. As a result, the fluid discharge side of the tubular housing 401 has a fluid discharge port 414 extending in the circumferential direction along the inner side surface of the tubular housing 401 .

In this way, by forming the path of the fluid in the tubular housing 401 in the direction away from the rotation axis from the fluid suction side toward the fluid discharge side, the centrifugal force generated in the tubular housing 401 on the fluid suction side is reduced. , the centrifugal force generated on the fluid discharge side can be increased.
The velocity of the fluid passing through the tubular housing 401 is accelerated from the fluid suction side toward the fluid discharge side as the centrifugal force increases. can be obtained.

Note that the propulsion device 40 of Modification 1 is provided with a conical rectifying projection 404 that tapers toward the discharge side and is formed at the end of the boss 402 on the fluid discharge side. In the example shown in FIG. 21, the fluid suction side of the rectifying projection 404 has a circular cross section with the same area as the cross section of the boss 302 on the fluid discharging side. and large. However, the rectifying protrusions may be configured to any size.

Further, the propulsion device 40 may have a casing 410 that rotatably accommodates the tubular housing 401 as in the first and second embodiments. FIG. 25 shows the configuration of the propulsion device 40 and the casing 410 of Modification 1. As shown in FIG. A casing 410 shown in FIG. 25 has a front casing 411 and a rear casing 412 and is fixed to the bottom of a ship or the like by a fixing portion 413 . Furthermore, although the casing 410 of FIG. 25 has the straightening vane 415 for adjusting the flow of the fluid in the rear casing 412, the straightening vane 415 has an arbitrary configuration.

(Modification 2)
In Embodiments 1, 2, and Modification 1 of Embodiment 3, the propulsion device has a configuration in which the rectifying protrusions are formed so as to protrude in a tapered manner on the fluid discharge side of the screw. In Modified Example 2, a configuration having shaft-like projections instead of rectifying projections will be described.

26 is a perspective view of the propulsion device 50 of Modification 2, FIG. 27 is a front view of the propulsion device 50, FIG. 28 is a rear view of the propulsion device 50, and FIG. 29 is a side view of the propulsion device 50. ing. As in the other embodiments, the propulsion device 50 obtains propulsion by sucking fluid from the fluid intake side on the right side of FIG. 26 and discharging fluid from the fluid discharge side on the left side of FIG.

The tubular housing ₅₀₁ of the propulsion device 50 shown in FIGS. r ₅₂ are configured to be equal.

Further, as in Modification 1 of Embodiment 3, the boss 502 of Modification 2 has a cross section that increases radially outward from the fluid intake side toward the fluid discharge side, and is tubular. The fluid discharge side of the housing 501 has a fluid discharge port 514 extending in the circumferential direction along the inner side surface of the tubular housing 501 .

Also, in the side view shown in FIG. 29, the tubular housing 501 has a recess 508 on the suction side edge and between two adjacent blades, although the recess 508 is an optional configuration.

As shown in FIGS. 26 and 29, the screw 500 has a shaft-like protrusion 516 protruding on the rotating shaft of the screw 500 toward the fluid discharge side. Here, the shaft-like projection 516 shown in FIG. 26 and the like is formed integrally with the boss 502 . However, the drive shaft 505 connected to the boss 502 on the fluid suction side of the boss 502 is configured to pass through the boss 502 , and the end of the drive shaft 505 protruding from the fluid discharge side of the boss 502 is a shaft-shaped protrusion. 516 may be used.

FIG. 30 also shows a casing 510 that rotatably accommodates the tubular housing 501 of the propulsion device 50 of Modification 2. As shown in FIG. The casing 510 has a front casing 511 and a rear casing 512 like the casing 111 . The casing 510 is fixed to the bottom of the ship or the like by a fixing portion 513 .

The rear casing 512 is arranged to face the discharge side of the tubular housing 501 and has a rectifying projection 504 tapered toward the fluid discharge side. By having such a rectifying projection 504, it is possible to rectify the fluid located around the rotation shaft among the fluid discharged from the tubular housing 401. FIG. In the example shown in FIG. 30 , the straightening protrusion 504 is fixed to the inner side surface of the rear casing 512 by a straightening plate 515 . However, instead of the rectifying plate 515, a simple supporting portion may be fixed to the inner side surface of the rear casing 512. FIG.

Further, a notch portion 517 is provided on the fluid intake side of the straightening projection 504 , and a bearing 518 is arranged inside the notch portion 517 . That is, when the shaft-shaped projection 516 protruding toward the fluid discharge side of the screw 500 is inserted into the notch 517 provided in the rectifying projection 504 of the rear casing 512, the bearing 518 arranged inside the notch 516 is rotatably supported by

(Summary)
The features of the propulsion device according to each embodiment of the present invention have been described above.

Although a plurality of embodiments and modifications thereof have been described, two or more features of each embodiment or modification may be included. That is, each embodiment can be combined with other embodiments or modifications. For example, by combining Embodiment 1 and Embodiment 4, a shaft-shaped projection projects from the fluid discharge side of the screw portion 100 of the propulsion device 10, and a straightening projection is provided on the casing 112, and the straightening projection is shaft-shaped. It may be configured to have a bearing that rotatably supports the projection.

In addition, elements of the configurations and methods disclosed in each embodiment can be appropriately combined with the present invention. In other words, the elements disclosed in each embodiment are not necessarily combined with each other, and each element can be appropriately incorporated as an invention.

INDUSTRIAL APPLICABILITY The present invention is mainly used in propulsion devices for ships, but the present invention is not limited to propulsion devices, and may be used in, for example, stirrers and generators.

10, 20, 30, 40, 50 propulsion devices 100, 200, 300, 400, 500 screws 101, 201, 301, 401, 500 tubular housings 102, 202, 302, 402, 502 bosses 103, 203, 303, 403, 503 blades 104, 204, 404, 502 straightening projections 105, 205, 305, 405, 505 drive shaft 106 inner edge 107 outer edge 108, 208, 308, 408, 508 recess 109 guide plate 110, 410, 510 casing 111, 411, 511 Front casings 112, 412, 512 Rear casings 113, 413, 513 Fixed parts 414, 514 Fluid discharge ports 415, 515 Current plate 516 Shaft-shaped projection
517 Notch 518 Bearing

Claims (9)

A propulsion device that sucks a fluid from the suction side and discharges it from the discharge side,
a screw having a plurality of blades arranged helically about the axis of rotation;
a tubular housing having the plurality of blades fixed to an inner side surface and rotating integrally with the plurality of blades;
the tubular housing has a recess in the direction of the axis of rotation at its suction-side edge and between adjacent blades ;
propulsion device. In the tubular housing, a first radius from the rotation axis to the inner side surface on the discharge side is smaller than a second radius from the rotation axis to the inner side surface on the suction side.
A propulsion system according to claim 1. In the tubular housing, a first radius from the rotation axis to the inner side surface on the discharge side is larger than a second radius from the rotation axis to the inner side surface on the suction side .
A propulsion system according to claim 1 . further comprising a casing that rotatably accommodates the tubular housing;
A propulsion device according to any one of claims 1 to 3 . The casing has a rectifying projection that is disposed opposite to the discharge side of the tubular housing and that protrudes tapered toward the discharge side.
5. A propulsion device according to claim 4 . The screw has an axial projection on the rotation axis of the screw and on the discharge side,
The rectifying projection has a bearing that rotatably supports the shaft-shaped projection,
6. A propulsion device according to claim 5 . A stirrer that sucks a fluid from the suction side and discharges it from the discharge side,
a screw having a plurality of blades arranged helically about the axis of rotation;
a tubular housing having the plurality of blades fixed to an inner side surface and rotating integrally with the plurality of blades;
the tubular housing has a recess in the direction of the axis of rotation at its suction-side edge and between adjacent blades ;
mixer. In the tubular housing, a first radius from the rotation axis to the inner side surface on the discharge side is smaller than a second radius from the rotation axis to the inner side surface on the suction side.
Agitator according to claim 7. In the tubular housing, a first radius from the rotation axis to the inner side surface on the discharge side is larger than a second radius from the rotation axis to the inner side surface on the suction side .
Agitator according to claim 7.

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