WO1990008061A1

WO1990008061A1 - Marine propulsion apparatus

Info

Publication number: WO1990008061A1
Application number: PCT/JP1990/000065
Authority: WO
Inventors: Shozaburo Yamazaki; Norihiko Goto; Norihiro Shiraishi; Kanji Okochi; Michihiro Kobayashi; Isao Sasada; Hatsuyuki Uemori; Taiji Nishimoto
Original assignee: Kabushiki Kaisha Kobe Seiko Sho
Priority date: 1989-01-20
Filing date: 1990-01-19
Publication date: 1990-07-26
Also published as: EP0406451A1; KR950003362B1; DE69002413T2; JPH085431B2; DE69002413D1; EP0406451A4; JPH02279490A; EP0406451B1; KR910700173A

Abstract

This invention relates to a marine propulsion apparatus. To improve propeller efficiency by utilizing the flow in the backward direction of a propeller shaft and the flow turning in the rotating direction of the propeller, the present invention provides a marine propulsion apparatus which has propeller vanes (2) and turbine vanes (3) fitted to the propeller shaft (1). The propeller vanes (2) are fitted on the front side and the turbine vanes (3), on the rear side, and an axial length (l) obtained by dividing the distance between the center lines of both vanes (2) and (3) by the diameter of the propeller is at least 6 % and the number of turbine vanes (3) is integral multiples of the number of propeller vanes (2). Furthermore, the diameter of the turbine vanes (3) is 33 to 60 % of the diameter of the propeller vanes (2) and the pitch angle ($g(U)p?) of the propeller vanes (2) and the pitch angle ($g(U)T?) of the turbine vanes (3) satisfy the relation $g(U)T? $g(U)p? + 20 at the position satisfying the relation 0.3 r/R 0.6.

Description

Akira i

Marine propulsion equipment technology

The present invention relates to a marine propulsion device.

Background technology

As a marine propulsion device (device), a tandem piper (Japanese Patent Application Laid-Open No. 57-205297) in which at least two sets of propellers are attached to the propulsion shaft with the propulsion shaft separated from the front and rear, the front and rear propeller diameters Tandem propellers (Japanese Utility Model Application Laid-Open No. 56-30195, Japanese Utility Model Application Laid-open No. 57-139500) and propeller labs with fins (Japanese Patent Application Laid-Open No. 63-154494). In the tandem propeller described above, the direction of the induced velocity induced by the front propeller accelerates the flow behind the propeller axis, and the direction of rotation is the same as the direction in which the propeller rotates in the same direction as the rotation direction. The efficiency of the rear propeller operating in the wake must be poor. For this reason, it was difficult to improve propeller efficiency with tandem propellers.

That is, the tandem propeller will be outlined with reference to FIGS. 9 to Π and FIGS. 30 to 31.

Fig. 9 shows a view of one propeller wing viewed from the rudder side. Let the radius of the propeller be R and the arbitrary radius position be r.

Cut the propeller blade with a cylinder of radius r and extend the cut Fig. 10 shows the exploded view. Propeller blades have a pitch similar to screws, and have a pitch angle to the direction of rotation (the so-called Nose-Tail Line, which connects the front of the wing and the rear of the wing, defines the pitch plane). The cross section of the wing has a chamber in front of the propeller (see Fig. 11). When the propeller turns and moves forward, water enters from the direction of i in the direction of rotation. (In Fig. 10, the propeller guided speed is induced by the rotation and forward movement of the propeller. Flow of water that is drawn into the propeller and stumbled in the direction of the propeller plane rotation). The lift L acting on the wing increases as the difference between Θ and β i, that is, as the elevation angle -i increases, and as the camber of the wing cross section increases.

The lift L acts at right angles to the water inflow direction, and its forward component is the thrust T and its rotational component is the rotational resistance F.

Τ = L cos β i

(1 set

F = L sin ^ i

The pitch and camber are determined so that the rotation torque and the rotation resistance torque Q = F X r transmitted from the engine are balanced, and the propeller efficiency is better as the ratio TZF between the thrust and the rotation resistance is larger.

V 0 ∞ T / F = cot β i (2)

Next, consider a tandem propeller. In the case of a tandem propeller, since the front propeller is located in front of the rear propeller, the guidance speed of the rear propeller is added, and as shown in Fig. 30, ^ i becomes slightly larger and becomes i '. As a result, as can be seen from equation (2)? ? o becomes smaller and the propeller efficiency becomes worse.

Similarly, for the rear propeller, the guidance speed of the front propeller is added to be placed in the wake of the front propeller (the propeller guidance speed is accelerated and becomes faster as going backward). The induction speed of the propeller itself is added, and /? I becomes i "as shown in Fig. 31. The rotational torque transmitted from the engine can be absorbed by the sum of the front and rear propellers. Since the propeller diameter, pitch, etc. are changed, it is not possible to conclude the improvement of efficiency only with the above explanation.However, the induction speed of the front and rear propellers has an adverse effect on each other, and the propeller efficiency is improved. The obvious is clear.

Next, the relationship between the propeller guiding speed, especially the propeller guiding speed in the stern wake and the propeller efficiency will be discussed using calculation examples based on propeller lifting surface theory and infinite blade number theory. The magnitude of the propeller guidance speed differs depending on the radius position of the propeller or the front-back position. As an example, the values obtained when the propeller designed for a medium-speed ship is rotating in a uniform flow using the propeller lifting surface theory and the infinite blade number theory are shown in Figs. 20 and 21. Is indicated by a solid line. Fig. 20 shows the distribution in the radial direction at the propeller position, and Fig. 21 shows the distribution in the front-rear direction at r / R = 0.3. In the figure, W _x is the propeller guidance speed that is sucked into the propeller and swept backward, and W e is the rotation of the propeller in the rotation direction. Propeller induction speed. It can be seen that both W _x and We are rapidly accelerated at the propeller position.

In practice, propellers operate in a complex stern stream, so propeller guidance speed also varies. Considering the flow at the stern propeller position, the viscous water causes the water near the hull surface to be pulled by the ship, and the flow at the propeller position is slightly slower than the ship speed Vs Vs (l—W ). Vs.W is the speed of the ice being pulled by the ship, this flow is called the wake, and W is the wake coefficient. The wake is unevenly distributed in the propeller disk. (This distribution is called the wake distribution.) Figure 22 shows the wake distribution of a medium-speed ship. As in the normal Fig. 22 in merchant ships, slow flow wakes rather large propeller _c in this wake in the wake higher blade tip side is the rather small flows are faster rotation at the center The calculation results of the propeller guidance speed during the wake are shown by broken lines in Fig. 20 and Fig. 21 <The wake is larger in the wake than in the uniform flow r / R = 0.2 to It can be seen that the propeller induction speed greatly increases in the range of rR = 0.6.

Propeller induction speed results in reduced propeller thrust and increased rotational resistance torque, ie, reduced propeller efficiency. Figures 23 and 24 show the radial distribution of thrust reduction and rotational resistance torque increase (propeller lifting surface theoretical calculation results) corresponding to the propeller guidance speed in Fig. 20. The solid line is the result during uniform flow, and the broken line is the result during wake. The thrust reduction due to the induction speed of the probe is In the wake, it increases to 10% of the propeller thrust, compared to 4% of the force. Both the rotational resistance torque and the increase due to the propeller induction speed are 21% of the whole in the uniform flow, but are increased to 28% in the wake. From FIGS. 23 and 24, it can be seen that both of them are concentrated at r = 0.2 to rR = 0.6 corresponding to the range of a large wake. Japanese Patent Application Laid-Open Publication No. 63-154494 discloses a fin-mounted perabo-cap (hereinafter abbreviated as PBCF) provided with a rectifying fin on a propeller-boacap. This rectifying fin acts as a rectifying plate to guide the water flow in the wake of the propeller boss trap in a direction to reduce the generation of hub vortices, and the hub vortices are diffused to form vortices on the propeller blade surface. It is said that the induced drag is reduced, but as mentioned above, the propeller efficiency depends on the propeller guidance speed, especially in the uneven stern wake. Without this, the effect cannot be sufficiently achieved.

The present invention was devised in order to solve the above-mentioned problems of the prior art.First, it was attempted to improve the propeller efficiency by installing a turbine blade behind the propeller blade and to reduce the torque. Aim.

In other words, the basic difference between a propeller and a turbine is that the former is a device that gives energy to a fluid and generates propulsion by the reaction force, whereas the latter is a device that rotates from the energy of the fluid. Devices that drive Also occurs in the opposite direction. Focusing on this fundamental difference, the above-mentioned first object was achieved.

According to the present invention, when the turbine blade is mounted on the rear side of the propeller blade, the turbine blade is created separately from the propeller boss and the propeller cap, and the turbine blade is formed between the propeller boss or the boss and the pier cap. The second object is to provide a marine propulsion device with turbine blades by using the existing cap as it is for the existing propeller by detachably mounting it on the propeller.

—Disclosure of Invention The present invention employs the following technical means to achieve the first object.

That is, the present invention relates to a marine propulsion device in which a propeller blade 2 and a turbine blade 3 are mounted on a propeller shaft 1, wherein the propeller blade 2 is mounted on a front side and the turbine blade 3 is mounted on a rear side. The shaft lengths of the turbine blades 3 are assumed to be 6% or more, the number of turbine blades 3 is an integral multiple of the number of blades of the propeller blades 2, and the diameter of the turbine blades 3 is smaller than that of the propeller blades 2. Marine propulsion characterized by a diameter of 33 to 60%. However, the axial length ^ is a value (%) obtained by dividing the distance between the center lines of the two wings 2 and 3 by the diameter of the opening propeller.

Further, the present invention is the pitch angle e _T of the pitch angle 6 _[rho and turbine blades 3 of a propeller blade 2 is, 0. 3≤ r / R≤0. At the position of 6 5 τ ≤ Θ p + 20 . By doing so, You have achieved 1 objectives.

The present invention employs the following technical means to achieve the second object.

That is, the turbine blade 3 mounted on the rear side of the propeller blade 2 has a flange 13A at its base, and the flange 13A is detachably screwed onto the outer periphery of the port Peravos 2A. This is the feature. Further, the turbine blade 3 mounted on the rear side of the propeller blade 2 has a ring 3A at its base, and the ring 3A is connected to the propeller boss 2A and the propeller cap 4 behind the boss 2A. It is characterized in that it is interposed between it and it in a removable manner. Further, the turbine blade 3 is characterized by being integrally formed with the ring 3A. Further, the turbine blade 3 is detachably attached to the ring 3A via a screw fastening means. Finally, the turbine blade 3 is characterized in that it is detachably fitted into an axial groove 3B formed on the outer periphery of the ring 3A along the axial direction.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view showing an embodiment of the present invention, FIG. 2 is a side view similarly, FIG. 3 is a flow field diagram of a wing cross section of a front propeller according to the embodiment of the present invention, FIG. The figure also shows the cross-sectional flow diagram of the rear turbine blade, respectively.Fig. 5 is an explanatory diagram showing the front-rear positional relationship between the propeller blade and the turbine blade, and Fig. 6 is the propeller efficiency A graph showing the relationship between the amount of turbine and the turbine blade position, Fig. 7 is a graph showing the relationship between the propeller efficiency increase and the number of turbine blades, and Fig. 8 is a propeller efficiency increase. Fig. 9 is a front view of one propeller blade, Fig. 10 is a flow field diagram of a cross section of a propeller blade, and Fig. 11 is a graph of a cross section of a propeller blade. Fig. 12 and Fig. 13 are side views of the essential parts showing two embodiments of the present invention in which a turbine wing is interposed between the propeller cap and the propeller cap, Figs. 14 to 16 Fig. 17 is a front view showing three examples of mounting the turbine blades on the ring. Fig. 17 is a side view of the main part where a turbine blade is mounted on a propeller boss via a flange. Fig. 18 is a flanged version. Fig. 19 is a side view of the turbine blade, Fig. 19 is a plan view, Fig. 20 is a graph showing the radial distribution of propeller induction speed (propeller position), and Fig. 21 is a front-rear distribution of propeller induction speed (r ZR = Graph showing 0.3), Fig. 22 is an explanatory diagram showing the wake distribution of medium-speed vessels, and Fig. 23 is propeller guidance. Graph showing the radial distribution of the thrust decrease by the speed, and e _P in FIG. 24 is a graph showing the radial distribution of the rotational resistance torque increase due to the propeller induced velocity, FIG. 25 medium speed marine propeller uniform flow is Comparison graph of ^ _{T i-} , Fig. 26 is a comparison graph of 0 F and _{T i in} the wake of a medium-speed ship propeller, and Fig. 27 is θ _? And 9 _T in the wake of another medium-speed ship propeller. _i comparison graph, comparison graph of Figure 28 fast marine propeller definitive to wake during e _P and ^ _{T i,} Figure 29 is a graph showing the relationship between the zero-lift angle and key Yanba ratio, FIG. 30 prior art Fig. 31 is a flow field diagram of the cross section of the wing of the front propeller of the tandem propeller. Fig. 31 is a flow field diagram of the cross section of the wing of the rear propeller. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments and operations of the present invention will be described with reference to the drawings.

In FIGS. 1 and 2, a propeller shaft 1 has a propeller blade 2 mounted on a front side (a traveling direction side or a hull side) and a turbine blade 3 mounted on a rear side, and the axial length of the two wings 2 and 3 is shown. £ (see Fig. 5) is 6% or more, the number of turbine blades 3 is an integral multiple of the number of propeller blades 2, and the diameter of turbine blades 3 is smaller than the diameter of propeller blades 2. The marine propulsion device is shown as 33-60%. In Fig. 2, 2A indicates propeller boss and 4 indicates cap.

However, the axial length is a value (%) obtained by dividing the distance between the center lines of the two wings 2 and 3 by the diameter of the opening propeller (see FIG. 5).

The geometry of the propeller blades 2 and turbine blades 3 is higher in pitch and

θ + α ο-β i> 0 Equation (3)

Whereas turbine blades

θ + ο-β i <0 (4)

Designed to. Note that “0 is the zero lift angle of the wing cross section (the angle between the water inflow direction and the pitch plane when the lift becomes zero). The forward is positive, the backward is negative, and the rear is negative. Zero means zero.

The basic difference between a propeller and a turbine is that the former (probe) is a device that gives energy to the fluid and gives propulsion by the reaction force, while the latter (turbine) is It is a device that receives rotational torque from the energy of

Fig. 3 and Fig. 4 show the flow fields at the cross section of the front propeller and the rear turbine blade of the propeller with turbine blades. As shown in Fig. 3, with a propeller blade, a thrust Τ _Ρ 'is obtained by applying a rotational torque equivalent to the rotational resistance F Ρ', while a thrust as shown in Fig. 4 is obtained with a turbine blade. Instead of being a backward-facing chi-car Τ _τ ", the rolling resistance becomes a car F _T " that reduces it. The thrust is generated by a propeller, and the turbine blade only functions as an auxiliary wing that reduces the rotational resistance torque by extracting energy from the wake of the propeller.The propeller with a turbine wing is completely different from a tandem propeller. It can be said that.

The induction speed of the turbine blade is generated in a direction completely opposite to that of the propeller. While the propeller induction speed is sucked into the propeller and rotates in the propeller rotation direction, the turbine blade induction speed pushes the flow forward and rotates in the opposite direction to the propeller rotation.

Consider the efficiency of a propeller with turbine blades. _P i is rather small and _{'P i} by induction speed of the turbine blades for the front propeller. As a result, the efficiency of the front propeller is improved. On the other hand, for the rear turbine blades, the direction of the generated force is opposite to that of the propeller, so the larger β i, the better the efficiency. In comparison with the _{P i} of the propeller blade ^ T i of data one bottle wing

β _{F i} β β T i (5)

If the turbine wing can be designed to meet The rates are even better. Ti is small at the front side of the propeller, and if a turbine blade is placed behind the propeller, the propeller guidance speed is accelerated and Ti becomes large, which is effective. Furthermore, when the wake of the propeller collides with the turbine blade surface, the turbine blade becomes a solid wall, and the effect of damping the wake of the propeller is also considered. In particular, if the turbine blade is placed in the wake of the propeller or while the propeller guidance speed is accelerating, the damming effect will be greater.

Also, from the relationship between the propeller guidance speed in the wake of the stern and the propeller efficiency, the effect of the propeller with a turbine blade is large in the wake, and the diameter of the turbine blade is large in the large wake range. It seems that it should be selected.

Based on the above considerations, for a 4-blade propeller for a high-speed ship, the efficiency of the propeller with turbine blades in the wake was changed by changing the number of blades, diameter, etc. of the turbine blades located behind. Calculated by lifting surface theory. For the front and rear positions of the turbine blade, the distance from the propeller center line to the turbine center line measured on the boss surface is divided by the propeller diameter, and the value when the turbine blade is placed behind the propeller is shown. Be positive (see Fig. 5). The turbine blade diameter is displayed as a percentage of the propeller diameter.

Tables 1 and 6 show the results obtained by changing the turbine blade number to 4 blades, changing the diameter to 45% of the propeller diameter, and changing the turbine blade position to 0%, 13%, and 20%. Shown in the figure. In the table, _{τ τ} is the thrust coefficient (-TZ pn ^ D p- _: T: thrust, p: water Density, n: propeller speed, D _P:. Propeller diameter), KQ if torque coefficient ^{_{^{(= QZ pn 2 D F 5}}} , Q = Torque), △ "efficiency A Tsubu amount compared to the efficiency of the propeller itself (% From these charts, if the turbine blades are located at the rear of the propeller, the propeller efficiency will be improved and the efficiency will be improved in consideration of the cost of turbine blade design and manufacturing 1.8. When limited to the range of more than%,

£> 6 式 (6)

Becomes

table 1

Table 2 and Fig. 7 show the results when the turbine blade position is jg = 13%, the turbine blade diameter is 45% of the propeller diameter, and the number of turbine blades is changed to 4, 8, and 12 blades. From these charts, it can be seen that if the number of turbine blades is an integral multiple of the number of propeller blades (1 to 3 times), the efficiency will increase by more than 1.8%. Table 2

The turbine blade position is 13%, the turbine blade number is 4 blades, and the turbine blade diameter is 25%, 35%, 45%, 55

Table 3 and Figure 8 show the results when the value was changed to 65%. From these charts, it can be seen that increasing the diameter of the turbine blade increases the amount of efficiency increase, while increasing it too much decreases the efficiency.

33% D _P <turbine blade diameter less than 60% DF It can be seen that efficiency up to 1.8% or more can be achieved in the range of Eq. (7).

Table 3

Next, the correlation between the pitch angle of the front propeller and the pitch angle of the rear turbine blade was investigated. Basically, a turbine blade can be obtained by determining the pitch and camber of the rear blade so as to satisfy Equation (4) .However, when Equation ( ⁴ ) is rewritten using the symbols in Fig. 4, the following equation is obtained. .

6 _τ + _το -β 'τι <0 (4)' where α _το : Zero lift angle of rear turbine blade

Here, if the rear wing _chamber is assumed to be zero, that is, if it is a flat plate, _το is zero, and the equation ( ⁴ ) ′ is

θ τ-9 'τ i <0 (8)

Furthermore, if the pitch angle τ of the rear wing is made to coincide with the direction β _{Ti of the} wake of the propeller, the induction speed by the rear wing becomes zero, and ' _Ti is equal to _Ti . In other words, the pitch angle of the flat rear wing is

If θ _τ <β Ti (9), the rear blade is a turbine blade.

Therefore, by Keimino the T _i using a propeller lifting surface theory and endless blades number theory, compared to _Ρ pitch angle of the propeller. The comparison results are shown in FIGS. 25 to 28. Fig. 25 shows the result of the middle-speed ship propeller in uniform flow, Fig. 26 shows the result of the same propeller wake as in Fig. 25, and Fig. 27 shows the result of another medium-speed ship propeller. Figure 28 shows the results during the wake of a high-speed propeller. In the _{_{figure, Ti (0),? T}} i (10), ^ T i (20) each ί = 0 ¾, 10%, a β at 20%. From this result, regardless of the flow into the propeller and the difference in the propeller itself, at 6% position

β d _P for 0.3 ≤ r / R ≤ 0.6 (10) Substituting this into equation ( ⁹ ) gives

θ τ <Θ p for 0.3 ≤ r / ≤ 0.6 (U). Equation (11) is for a flat plate.

θ _τ <Θ p-a _t0 for 0.3 ≤ r / R ≤ 0.6 02) An example of the relationship between the camber ratio (= camberno span) and ". Is shown in Fig. 2'9. From Fig. 29, it can be said that the zero lift angle changes by approximately 1 for a camber ratio of 1%. Assuming that the turbine blade is mounted at the rear and the chamber ratio is up to 20%, Equation 02)

T≤ e _F +20. for 0.3≤ r / R≤0.6 (13) (Note that R is the propeller radius in the formula αο) to ³ ). In other words, if the pitch angle of the rear blade is selected at r ZR O.3 to r ZR = 0.6 so as to satisfy the expression to), the blade will be a turbine blade, and the above-mentioned effect is expected. When r ZR <0.3, / 9 _Ti increases rapidly, and even if θ _{かなり} is _set to a considerably large value, it becomes a turbine blade, so there is no particular limitation here. Even if τ is selected so as not to satisfy Equation (13) in a part of the range between r ZR = 0.3 and r no R = 0.6, it is possible to design the whole blade to have the function of a turbine blade. It is believed that the aforementioned effects are reduced. Referring to FIGS. 12 to 19, installation of turbine blade 3 (Attachment) Some embodiments of the means are illustrated. Figs. 12 and 13 show the ring 3A provided at the base of the turbine blade 3 on the propeller shaft 1 with the ring interposed between the propeller boss 2A and the propeller cap 4 behind the boss. In this case, propeller boss 2A, ring 3A and cap 4 are fastened together by bolt 5 in Fig. 12. Fig. 13 shows an example in which a ring 3A is fastened to a propeller boss 2A with a bolt 6 and a cap 4 is fastened to a ring 3A with a bolt 7. As shown in FIG. 16, the bolts 5, 6, 7 are fastened using the bolt insertion holes 3C formed in the ring 3A in the axial direction in a radial arrangement.

17 to 19 show an embodiment in which the turbine blade 3 is detachably mounted on the outer peripheral surface of the propeller boss 2A by screw fastening means.The turbine blade 3 has a fastening hole 13B at its base. The flange 13A has a flat plate shape, and the flange 13A is superimposed on the outer peripheral surface of the propeller boss 2A, and the bolt 13C is passed through each of the fastening holes 13B, and each bolt 13C is fastened to the female screw formed on the boss. It becomes.

FIGS. 14 to 16 show the relationship between the ring 3A and the turbine blade 3, and FIG. 14 shows that a groove 3B is formed in the axial direction at the outer radial position of the ring 3A. A dovetail-shaped projection 3D formed on the base of the turbine blade 3 in a state where the base end surface of the turbine blade 3 is superimposed on the outer peripheral surface of the ring 3A is fitted into the groove 3B from the axial direction. In this example, the projection 3D Axial restrictions are enforced by Propeller Boss 2 A and Propeller Cap 4.

FIG. 15 shows an embodiment in which the turbine blade 3 and the ring 3A are integrally formed by a metal or welding. In the embodiment shown in FIGS. 17 to 19, the turbine blade 3 and the flange 13A are integrally formed in the same manner as described above.

FIG. 16 shows an embodiment in which a mounting hole 3E is formed in a ring 3A in a radial arrangement, a projection 3D having a screw portion is passed through the mounting hole 3E, and a nut 8 is used to fasten the screw. .

In each of the above-described embodiments, the ring 3A can be a split ring, and the turbine blade 3 can be provided with mounting angle adjusting means.

Further, the turbine blade 3 and the ring 3A or the flange 13A can be made of the same material (for example, copper alloy) as the mouth prop or a composite material such as FRP.

The present invention is as described above, and the turbine blade is provided behind the propeller blade.Therefore, as the propeller guiding speed increases, that is, as the flow to the rear of the propeller shaft increases, the squeezing occurs in the rotation direction. The larger the flow is, the more effective it is, and here the propeller efficiency can be improved.

In addition, since the torque is reduced, the rotation of the propeller became heavy due to the fouling of the hull and the aging of the main engine of the existing ship, and the rotation was reduced if the turbine blade was attached to the propeller. You can do it.

In addition, the turbine blade has a flange or ring at the base. The flanges on the outer periphery of the propeller boss or the ring between the boss and the flapper cap are detachable, so that the existing cap can be used for the existing propeller as it is. The propulsion device with turbine blades can be retrofitted at low cost, and the appropriate thickness of the ring allows the turbine blades to be installed in an integrated, welded, inset, bolted, etc. It is much freer and easier to design and manufacture.

INDUSTRIAL APPLICABILITY The present invention can be used for a marine propulsion device in which a propeller shaft and a turbine blade are mounted on a propeller shaft.

Claims

The scope of the claims

(1) A marine propulsion device in which a propeller blade (2) and a turbine blade (3) are mounted on a propeller shaft (1),

The propeller wing (2) is mounted on the front side and the turbine wing (3) is mounted on the rear side. The axial length of the two wings (2) and (3) is set to 6% or more. The number of blades is an integral multiple of the number of blades of the propeller blade (2), and the diameter of the turbine blade (3) is 33 to 60% of the diameter of the propeller blade (2). Marine propulsion equipment.

However, the wheel length is a value (%) obtained by dividing the distance between the center lines of the two wings (2) and (3) by the propeller diameter.

(2) When the pitch angle (P) of the propeller blade (2) and the pitch angle ( _τ ) of the turbine blade (3) are 0.3 ≤ r / R ≤ 0.6, e _T ≤ _Ρ +20. The marine propulsion device according to claim 1, wherein:

However, (R) is the radius of the propeller blade, and (r) is any radius position.

(3) The turbine wing (3) mounted on the rear side of the propeller wing (2) has a flange (13A) at its base, and the flange (13A) is attached to the outer periphery of the propeller boss (2A). 2. The marine propulsion device according to claim 1, wherein the marine propulsion device is detachably screwed onto the upper part.

(4) The turbine wing (3) mounted on the rear side of the propeller wing (2) has a ring at its base (30), and the ring (3A) is connected to the mouth perabos (2A) and the boss. (2A) Rear propeller cap 2. The marine propulsion device according to claim 1, wherein the marine propulsion device is detachably fixed between the marine propulsion device and (4).

(5) The marine propulsion according to claim 4, wherein the turbine blade (3) is formed integrally with the ring (3A).

(6) The marine propulsion device according to claim 4, wherein the turbine wing (3) is detachably fixed to the ring (3A) via screw fastening means. .

(7) The turbine blade (3) extends axially around the outer circumference of the ring (3A).

The marine propulsion according to claim 4, characterized in that the marine propulsion is removably fitted into the ten groove grooves (3B).

Fifteen

20

twenty five