JPH07165181A - Propulsion device for vessel - Google Patents

Abstract

PURPOSE:To provide a propulsion device for a vessel which can improve the acceleration performance with a simple constitution in a double propeller structure. CONSTITUTION:As for a propulsion device for a vessel which is equipped with an engine 9 arranged in the upper part in a casing 8, advance/retreat propeller 7 which is revolved in the normal and reverse directions in the advance and retreat by a driving power of the engine, and an advance propeller 6 which is arranged continuously in the axial direction with the advance/retreat propeller 7 and revolves in the reverse direction to the advance/retreat propeller 7 at least in advance, an air flow passage A for introducing air toward the wing surface of at least one propeller in advance is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a marine vessel propulsion device having a pair of propellers arranged to face each other in the front-rear direction.

[0002]

2. Description of the Related Art For example, Japanese Patent Publication No.
As disclosed in Japanese Patent No. 60879, there is one provided with a pair of propellers arranged so as to face each other in the front-rear direction.

In this type, an engine is arranged in an upper part of a casing, an underwater exhaust passage for discharging exhaust gas of the engine into water is provided, and a forward / reverse propeller for rotating forward and backward by the power of the engine is provided. The forward-reverse propeller is provided adjacent to the front-rear propeller in the axial direction in the front-rear direction, and includes a forward propeller that rotates in the opposite direction to the forward-reverse propeller at least during forward movement.

[0004]

As described above, by disposing a pair of propellers facing each other in the front and rear and rotating them in opposite directions, that is, by forming a double propeller structure, propulsion efficiency is improved. It is well known that improvements can be made.

However, by adopting a double propeller structure, the propulsion efficiency can be improved, but since two propellers need to be rotated, they are used in a state in which the load applied to the engine during acceleration is too large. So, I could not raise the engine speed quickly,
The problem of poor acceleration occurs.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a propulsion device for a ship, which has a double propeller structure and can improve acceleration performance with a simple structure.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that an engine is arranged in an upper part of a casing, and forward / backward rotation is performed by the power of the engine in forward / reverse rotation. In a propulsion device for a ship, which is provided with a propeller and an advancing propeller arranged axially adjacent to the forward / reverse propeller and rotating at least in a direction opposite to the forward / reverse propeller during forward movement, the at least one propeller during forward movement. It is characterized by forming an air flow path for guiding air toward the blade surface of the.

The invention according to claim 2 is characterized in that the supply portion of the air flow path is provided in front of the front side propeller and at a position facing the propeller.

[0009]

According to the first aspect of the invention, at the time of forward movement, the forward and backward propellers and the forward propeller rotate in opposite directions to function as a double propeller, so that good propulsion efficiency can be obtained.
On advancing, air is guided by the air flow path and hits at least one propeller. Therefore, during acceleration, the load on at least one of the propellers decreases due to air, and the engine speed increases quickly.

According to the second aspect of the present invention, the air passage supply portion is provided in front of the front propeller and at a position facing the propeller, and the air passage supply portion is provided from the supply portion toward the front propeller. Air is discharged, and during acceleration, the load on the front propeller is reduced by the air, and the engine speed rises quickly.

On the other hand, the rear propeller is less likely to be hit by air than the front propeller, so that the propeller can obtain a propulsive force. Here, the propeller that applies air is the front propeller, and the propeller that does not directly apply air is the rear propeller, so the propeller on the side that obtains the propulsion force, that is, the water flow generated by the rear propeller, is applied to the other propeller. It smoothly flows backward without being disturbed, and sufficient propulsive force is obtained to improve acceleration.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a ship propulsion apparatus of the present invention will be described in detail below with reference to the drawings. 1 is a side view of a propulsion device provided in a ship, FIG. 2 is a partial cross-sectional view of the propulsion device of the ship, FIG. 3 is a view A in FIG. 2 in which a forward propeller and a forward / backward propeller are omitted, and FIG. 5 is a perspective view of the main part of the propulsion device of FIG. 5, FIG. 5 is a side view of the main part of the propulsion device of the ship, and FIG.
FIG.

A mounting box 2 is provided on the hull 1 of a small boat, and a clamp bracket 3 is mounted on the mounting box 2.
Is fixed. A swivel bracket 4 is attached to the clamp bracket 3 so as to be vertically rotatable about a tilt shaft extending in the horizontal direction, and a propulsion device 5 is attached to the swivel bracket 4 so as to be horizontally rotatable. The propulsion device 5 is provided with a pair of forward and backward propellers 6 and 7 which are arranged to face each other in the front and rear direction.

The propulsion device 5 has a casing 8,
An engine 9 is arranged in the casing 8.
Further, an exhaust expansion chamber 10 communicating with outside water is provided inside the casing 8, and the engine 9 is installed in the exhaust expansion chamber 10.
Exhaust gas is discharged from the underwater exhaust passage 11 connected to. At high speed, the exhaust gas is mainly guided from the exhaust expansion chamber 10 to the underwater exhaust passage 11 formed in communication with the water, and is exhausted into the water through the underwater exhaust port 12 formed in the casing 8. Further, an air exhaust port 13 communicating with the air is formed in the casing 8, and at a low speed, exhaust gas is guided from an upper portion of the exhaust expansion chamber 10 to an exhaust passage 14 mainly formed in the casing 8, and the exhaust passage 14 From the air exhaust port 13
Is discharged into the air through.

A drive shaft 15 is connected to the engine 9. The drive shaft 15 is vertically arranged in the casing 8, and the horizontal bevel gear 1 is provided below the drive shaft 15.
6 is provided. Two vertical bevel gears 17 and 18 arranged to face each other mesh with the horizontal bevel gear 16.

The two vertical bevel gears 17 and 18 are rotatably supported by a forward / backward propeller shaft 19, and the forward / backward propeller shaft 19 extends to a rearward / forward forward propeller 7. The vertical bevel gear 17 is axially supported on the casing 8 via a bearing 20, and the vertical bevel gear 18 is supported on a ring 22 via a bearing 21.
2 is pressed into the front side of the cylindrical body 23. The front side of the cylindrical body 23 is in contact with the spacer 24, and the rear side is fastened with the nut 25 and fixed to the casing 8.

A forward propeller shaft 28 is rotatably provided between the cylindrical body 23 and the forward / backward propeller shaft 19 via bearings 26 and 27, respectively.
8 extends to the forward propeller 6 at the rear.

The front end of the spacer 29 is brought into contact with a taper portion formed on the outer periphery of the rear portion of the forward propeller shaft 28, and the sleeve 30 is brought into contact with the spacer 29 to spline-engage the outer periphery of the forward propeller shaft 28 with the spacer 31. Is inserted to position the sleeve 30, and the sleeve 30 is fixed to the forward propeller shaft 28 with a nut 33 via a washer 32. A rubber damper 3 is provided on the outer circumference of the sleeve 30.
4 is baked and fixed, and the inner boss 6a of the forward propeller 6 is pressed into the outer periphery of the rubber damper 34, and the rotational force of the rubber damper 34 is changed by frictional force.
Is transmitted to the inner boss 6a.

A spacer 35 is inserted in the rear portion of the forward / backward propeller shaft 19 in proximity to the nut 33 via a washer 36, and is in contact with a tapered surface formed on the forward / backward propeller shaft 19 so as to contact the spacer 35. Contact sleeve 37
Is spline-engaged with the forward / backward propeller shaft 19, the spacer 38 is further inserted to position the sleeve 37, and the sleeve 37 is fastened and fixed to the forward / backward propeller shaft 19 with a nut 40 via a washer 39. . A rubber damper 41 is baked and fixed on the outer periphery of the sleeve 37, and the inner boss 7a of the forward / backward propeller 7 is press-fitted on the outer periphery of the rubber damper 41 so that the rotational force of the rubber damper 41 is generated by frictional force inside the forward / backward propeller 7. Boss 7a
Be transmitted to.

Reference numeral 6d denotes an outer boss connected to the inner boss 6a by a plurality of ribs extending in the axial direction of the forward / backward propeller shaft 19, and the exhaust passage 100 is provided between the inner boss 6a and the outer boss 6d of the forward propeller 6. Has been formed. Similarly, the forward / reverse propeller 7 also has an inner boss 7a and the inner boss 7a.
An exhaust passage 101 is formed between the outer bosses 7d connected to each other by a plurality of ribs.

The outer diameters of the inner boss 6a and the outer boss 6d of the forward propeller 6 and the outer diameters of the inner boss 7a and the outer boss 7d of the forward / backward propeller 7 are formed to have substantially the same diameter. The inner peripheral surface of the exhaust passage 101 formed from the outer peripheral surface of 23 to the outer peripheral surface of the inner boss 7a becomes substantially the same surface, and the exhaust gas flows smoothly.

The front side portion 6 of the outer boss 6d of the forward propeller 6
e is the outer peripheral portion 1 of the passage 102 formed in the casing 8.
03, and the front side portion 7e of the outer boss 7d of the reverse propeller 7 is engaged with the inside of the rear side portion 6f of the outer boss 6d.

The underwater exhaust passage 11 of the casing 8 is communicated with an underwater exhaust port 12, and the underwater exhaust port 12 is formed by an opening 23b formed in a cylindrical body 23 and a nut 25, and is discharged from the underwater exhaust port 12. The exhaust gas is exhausted rearward through the exhaust passage 100 of the forward propeller 6 and the exhaust passage 101 of the forward / backward propeller 7.

An underwater exhaust port 111 communicating with the underwater exhaust passage 11 is formed in the skeg 110 of the casing 8, and the underwater exhaust port 111 is located at a position facing the blade surface of the forward propeller 6. Exhaust gas is discharged from the underwater exhaust port 111 toward the blade surface of the forward propeller 6, and during acceleration, the load of the forward propeller 6 is reduced by the exhaust gas and the engine speed is quickly increased. Exhaust gas is less likely to hit the forward / reverse propeller 7 than the forward propeller 6, and acceleration is improved by obtaining propulsive force with the forward / reverse propeller 7.

A shift shaft 42 is vertically arranged on the front side of the drive shaft 15, and a pin 42a formed at an eccentric position of the shift shaft 42 is inserted into the connecting shaft 43. By manually rotating the shift shaft 42, the connecting shaft 43 is moved in the front-rear direction. The connecting shaft 43 is connected to the clutch shaft 45 of the clutch 44, and the clutch shaft 45 is located in the axial hole 1 on the front side of the forward / backward propeller shaft 19.
The clutch shaft 45 is provided on the shaft 9a so as to be slidable in the axial direction, and the clutch shaft 45 is moved in the axial direction by the connecting shaft 43.

The clutch shaft 45 is composed of a sleeve 46 and a rod 47 inserted into the sleeve 46. A pair of balls 48 and 49 are arranged in the sleeve 46, and the compression spring 5 is provided between the pair of balls 48 and 49.
0 is provided so that the stopper balls 51 and 52 provided at two positions of the sleeve 46 are always urged to project outward.

A projection 19b is formed in the hole 19a of the forward / backward propeller shaft 19, and recesses 19c and 19d are formed on both sides of the projection 19b. The neutral position is when the stopper ball 51 of the clutch shaft 45 is in contact with the protrusion 19b, the forward position is when it is in the recess 19c, and the reverse position is when it is in the recess 19d.

Two pins 53, 54 are inserted through the rod 47 of the clutch shaft 45 at right angles to the axial direction, and the respective pins 53, 54 are two elongated holes 19e formed in the forward / backward propeller shaft 19. , 19f, and sliders 55, 56 are connected to the pins 53, 54, and the sliders 55, 56 are provided so as to be annular as a whole so as to cover the long holes 19e, 19f.

The slider 55 is spline-engaged with the forward / backward propeller shaft 19 so as to be integrally rotatable, and the left and right axial ends of the slider 55 have dock claws 55a,
55b, and the dock claws 55a and 55b face the dock claws 18a and 17a formed on the vertical bevel gears 17 and 18, respectively. The slider 56 has a spline formed on the outer peripheral surface thereof and is spline-engaged with a spline formed on the inner peripheral surface of the forward propeller shaft 28 so as to be integrally rotatable, and the left end portion of the slider 56 in the axial direction. The vertical claw gear 1 has a dock claw 56a.
It faces the dock claw 18b formed in FIG.

Therefore, when the shift shaft 42 is rotated during forward movement, the clutch shaft 45 of the clutch 44, which was in the neutral position, is moved leftward via the connecting shaft 43, and at the same time, the pins 53 and 54 are both elongated holes 19e. , 19f to the left, the left dog claw 55b of the slider 55 engages with the inner dog claw 17a of the vertical bevel gear 17, and the dog claw 56a of the slider 56 engages with the outer dog claw 18b of the vertical bevel gear 18. To meet.

At this time, as the drive shaft 15 rotates, the left vertical bevel gear 17 rotates in the clockwise direction when viewed from the rear of the propulsion device (hereinafter referred to as right rotation). Propeller shaft 19, sleeve 3
7. The forward / backward propeller 7 rotates clockwise through the rubber damper 41. Further, since the right vertical bevel gear 18 rotates counterclockwise, the forward propeller 6 rotates in the opposite direction at the same speed as the forward / backward propeller 7 via the slider 56, the forward propeller shaft 28, the sleeve 30, and the rubber damper 34. To do. Therefore, at the time of forward movement, since it functions as a double propeller, good propulsion efficiency can be obtained.

The outer surface of the casing 8 has a water surface L1 at low speed.
Between the vehicle and the water surface L2 at high speed, a splash plate 120 that suppresses splash, that is, splashes, on the upper part of the outboard motor during gliding, and a cavitation located above the propeller position so as not to entrain air on the propeller side. The plate 121 is formed. A cutout 120a is provided on the rear side of the splash plate 120, and a cutout 121a is provided on the front side of the cavitation plate 121. The notch 120a on the rear side of the splash plate 120 and the notch 121a on the front side of the cavitation plate 121 form an air flow path A that guides air toward the blade surface of the forward propeller 6 during forward movement. The supply part of the air flow path a is provided above the front of the forward propeller 6 and at a position facing the blade surface of the forward propeller 6.

At a low speed, the water surface L1 is located above the splash plate 120, but at the time of acceleration, the water level L1 drops to a position above the cavitation plate 121, and the rotation of the propeller increases with acceleration. Splash plate 12
The air flow path A formed by the notch 120a on the rear side of 0 and the notch 121a on the front side of the cavitation plate 121 is guided toward the blade surface of the forward propeller 6, and the air hits the forward propeller 6. Therefore, during acceleration, the load on the forward propeller 6 is reduced by the air, and the engine speed is quickly increased.

On the other hand, the reverse propeller 7 on the rear side is not directly contacted with air, and propulsive force can be obtained by the reverse propeller 7.
Here, the propeller that applies air is the forward propeller 6 on the front side.
Since the propeller that does not directly apply air is the rearward-direction reverse propeller 7, the propeller on the side that obtains the propulsive force, that is, the water flow generated by the rearward-direction reverse propeller 7 is not disturbed by the other forward propeller 6. It flows smoothly to the rear, sufficient propulsion is obtained, and acceleration is improved.

At high speed, the water pressure due to propulsion is so strong that the air is suppressed by the water pressure and the forward propeller 6
It flows backwards along the top surface of the cavitation plate without hitting. Therefore, at high speed, both propellers 6,
Air is prevented from hitting 7, and good propulsion efficiency is obtained.

FIG. 7 is a perspective view of a main part of the propulsion device for a ship. In the marine vessel propulsion apparatus of this embodiment, the same structures as those of the embodiment shown in FIGS. 1 to 6 are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, the splash plate 1
Although the notch 120a is provided on the rear side of 20, the cavitation plate is not provided, and an air flow path A for guiding air to the forward propeller 6 by the rotation of the propeller at the time of forward movement is formed. The supply part of the air flow path A is provided at the front upper side of the forward propeller 6 on the front side and at a position facing the blade surface of the forward propeller 6.

FIG. 8 is a perspective view of a main portion of the marine vessel propulsion device, FIG. 9 is a side view of the main portion of the marine vessel propulsion device, and FIG. 10 is a plan view of FIG. In the propulsion device for a ship of this embodiment,
Structures similar to those of the embodiment shown in FIGS. 1 to 6 are designated by the same reference numerals, and description thereof will be omitted.

In this embodiment, the splash plate 1
The rear side of 20 extends to the front upper position of the forward propeller 6,
The front side of the cavitation plate 121 extends to the center of the splash plate 120. At the front upper position of the forward propeller 6, the cavitation plate 12 is
1 is provided with air supply openings 122 on both sides thereof, and the air supply openings 122 are opened and closed by a reed valve 123. The air supply openings 122 and the reed valve 123 cause air to move to the blade surface of the forward propeller 6 by the rotation of the propeller during forward movement. An air flow path A is formed to guide the air flow. The supply portion of the air flow path A is provided in the front upper part of the forward propeller 6 on the front side and at a position facing the forward propeller 6.

At low speed, the water surface is splash plate 1
Although it is in the upper position of 20, the position of the cavitation plate 121 is lowered during acceleration, and when the rotation of the propeller rises due to acceleration, the reed valve 123 is opened by the suction force due to the rotation of the propeller and the air is removed from the cavitation plate 121. The air supply opening 122 guides the air to the forward propeller 6, and the air hits the blade surface of the forward propeller 6. Therefore, during acceleration, the load on the forward propeller 6 decreases due to air, the engine speed increases rapidly, and the forward / reverse propeller 7 that rotates in the reverse direction behind the forward propeller 6 obtains propulsive force, thereby improving the acceleration performance. improves.
If the rotation of the propeller is below a certain level, the reed valve 12
3 does not open. Further, at high speed, since the water pressure due to the propulsion is strong, the reed valve 123 is closed by the water pressure and the air supply is suppressed so that the air does not hit the forward propeller 6 and flows backward along the upper surface of the cavitation plate 121. Therefore, at high speed, air is prevented from hitting both propellers 6 and 7, and good propulsion efficiency is obtained.

FIG. 11 is a perspective view of the main part of the propulsion device for a ship,
12 is a side view of the main part of the propulsion device of the ship, and FIG. 13 is FIG.
It is a top view in 2. In the marine vessel propulsion apparatus of this embodiment, the same structures as those of the embodiment shown in FIGS. 1 to 6 are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, the splash plate 1
The rear side of 20 extends to the front upper position of the forward propeller 6,
The front side of the cavitation plate 121 extends to the center of the splash plate 120. Casing 8
A guide 124 is formed on one side portion of the guide 124. An air inlet 124a of the guide 124 is located above the position of the water surface L1 at low speed, and an air outlet 124b is formed on the cavitation plate 121. An air flow path A is formed that guides air to the blade surface of the forward propeller 6 by rotation of the propeller during acceleration. The supply portion of the air flow path A is provided in the front upper part of the forward propeller 6 on the front side and at a position facing the forward propeller 6.

At low speed, no air is sucked by the rotation of the propeller, but at the time of acceleration, the rotation of the propeller rises so that the air is sucked through the guide 124 by the rotation of the propeller and guided to the forward propeller 6 by the air discharge port 124b. , The air hits the forward propeller 6. Therefore, during acceleration, the load on the forward propeller 6 decreases due to air, the engine speed increases rapidly, and the forward / reverse propeller 7 that rotates in the reverse direction behind the forward propeller 6 obtains propulsive force, thereby improving the acceleration performance. improves.

Further, at high speed, since the water pressure due to propulsion is strong, the air discharge port 124b is closed by the water pressure and the supply of air is suppressed.
The air is prevented from hitting, and good propulsion efficiency is obtained.

FIG. 14 is a perspective view of the main part of the propulsion device for a ship. In the propulsion device for a ship according to this embodiment, FIGS.
Structures similar to those of the embodiment shown in FIG. In this embodiment, a single air suction port 125a is formed on one side of the cavitation plate 121, a guide 125 is formed inside the casing 8 from this air suction port 125a, and an air discharge port 125b of this guide 125 is moved to the forward propeller. An air passage A is formed on the front side of 6 to guide the air toward the blade surface of the forward propeller 6 by the rotation of the propeller during acceleration. The supply part of the air flow path A is provided in front of the forward propeller 6 on the front side and at a position facing the forward propeller 6.

Since the rotation of the propeller rises during acceleration, the rotation of the propeller guides air from the air intake 125a of the cavitation plate 121 to the forward propeller 6 by the guide 125, and the air hits the blade surface of the forward propeller 6. Therefore, during acceleration, the load on the forward propeller 6 decreases due to air, the engine speed increases rapidly, and the forward / reverse propeller 7 that rotates in the reverse direction behind the forward propeller 6 obtains propulsive force, thereby improving the acceleration performance. improves.

Further, at high speed, since the water pressure due to propulsion is strong, the air supply port 125b of the guide 125 is closed by the water pressure to suppress the supply of air, so that at high speed, both propellers 6 and 7 may hit the air. It is prevented and good propulsion efficiency is obtained.

FIG. 15 is a side view of the main part of the propulsion device for a ship,
16 is a plan view of FIG. 15, and FIG. 17 is a view B of FIG. 15 in which the forward propeller and the forward / backward propeller are omitted. Structures similar to those of the embodiment shown in FIG. 14 are designated by the same reference numerals, and description thereof will be omitted. In this embodiment, air suction ports 126a are formed on both sides of the cavitation plate 121 of the casing 8, and the air suction ports 126a are formed.
To the inside of the casing 8, guides 126 are respectively formed, and the guides 126 are assembled to collect the air exhaust port 126.
b is located on the front side of the forward propeller 6, and an air flow path A that guides air toward the blade surface of the forward propeller 6 by rotation of the propeller during acceleration is formed.

Further, by providing a pair of air suction inlets 126a on both sides of the cavitation plate 121, more air is applied to the forward propeller 6 during acceleration to improve the acceleration performance.

FIG. 18 is a perspective view of the main part of the propulsion device for a ship,
FIG. 19 is a side view of the main part of the propulsion device of the ship, and FIG. 20 is FIG.
9 is a plan view of FIG. 9, and FIG. 21 is a C view of FIG. 19 in which the forward propeller and the forward / backward propeller are omitted. 14
Structures similar to those of the embodiment shown in FIG. In this embodiment, an air intake port 127a is provided on one side of the casing 8 and the air intake port 127 is provided.
The guide 127 is formed inside the casing 8 from a.
The air outlet 127b of the guide 127 is located on the front side of the forward propeller 6, and an air flow path A for guiding air toward the blade surface of the forward propeller 6 by the rotation of the propeller during acceleration is formed.

Incidentally, the forward propeller 6 in the embodiment
Rotates in the direction opposite to the forward / backward propeller 7 only when moving forward,
Although it is configured to rotate idly when moving backward, it may be configured to rotate in the direction opposite to the forward / backward propeller 7 not only when moving forward but also when moving backward. The air may be applied not only to the forward propeller 6 but also to the forward / backward propeller 7.

[0052]

As described above, according to the first aspect of the present invention, since air is guided by the air flow path when moving forward and the air hits at least one propeller, at the time of acceleration, the load of at least one propeller is increased by the air. Lowers, the engine speed increases faster, and acceleration is improved.

According to the second aspect of the present invention, since the air passage supply portion is provided in front of the front propeller and at a position facing the propeller, air flows from the supply portion toward the front propeller. When exhausted and accelerated, the air reduces the load on the front propeller, causing the engine speed to rise faster, while the rear propeller is less likely to hit air than the front propeller, and this propeller provides propulsion. To be In particular, the propeller that applies air is the front propeller, and the propeller that does not directly apply air is the rear propeller.Therefore, the water flow generated by the propeller that obtains the propulsion force, that is, the rear propeller, interferes with the other propeller. It flows smoothly to the rear without being hit, and sufficient propulsive force is obtained to improve acceleration.

[Brief description of drawings]

FIG. 1 is a side view of a propulsion device provided in a ship.

FIG. 2 is a partial cross-sectional view of a propulsion device for a ship.

FIG. 3 is a view in which a forward propeller and a forward / backward propeller are omitted.
FIG.

FIG. 4 is a perspective view of a main part of a propulsion device for a ship.

FIG. 5 is a side view of a main portion of a propulsion device for a ship.

FIG. 6 is a plan view of FIG.

FIG. 7 is a perspective view of a main part of a propulsion device for a ship.

FIG. 8 is a perspective view of a main part of a propulsion device for a ship.

FIG. 9 is a side view of a main portion of a propulsion device for a ship.

10 is a plan view of FIG.

FIG. 11 is a perspective view of a main portion of a propulsion device for a ship.

FIG. 12 is a side view of a main part of a propulsion device for a ship.

13 is a plan view of FIG.

FIG. 14 is a perspective view of a main part of a propulsion device for a ship.

FIG. 15 is a side view of a main portion of a propulsion device for a ship.

16 is a plan view of FIG.

FIG. 17 is a B view in FIG. 15 in which a forward propeller and a forward / backward propeller are omitted.

FIG. 18 is a perspective view of a main portion of a propulsion device for a ship.

FIG. 19 is a side view of the main part of the propulsion device for a ship.

20 is a plan view of FIG.

FIG. 21 is a C view in FIG. 19 in which the forward propeller and the forward / backward propeller are omitted.

[Explanation of symbols]

 6 Forward propeller 7 Forward / backward propeller 8 Casing 9 Engine A Air flow path

Claims (2)

[Claims] 1. An engine is arranged in an upper part of a casing, and a forward / backward propeller that rotates forward and backward by the power of the engine in forward and reverse directions, and an adjoining axially adjacent to the forward / backward propeller and at least forward movement. In a propulsion device for a ship, which is sometimes provided with the forward-backward propeller and a forward propeller that rotates in the opposite direction, an air flow path that guides air toward a wing surface of the at least one propeller during forward movement is formed. Ship propulsion device. 2. A propulsion device for a marine vessel, wherein the air flow path supply portion is provided in front of a front side propeller and at a position facing the propeller.