JPH0626476Y2 - Marine propeller - Google Patents

Description

TECHNICAL FIELD The present invention relates to a propeller for a ship.

2. Description of the Related Art Conventionally, marine propellers have various shapes in order to reduce frictional resistance generated in the propellers.

Problems to be Solved by the Invention According to the above propeller, only the shape of the propeller blade itself is taken into consideration, and no special mechanism for reducing the frictional resistance is adopted. There was a limit.

Therefore, the inventors of the present invention have found that the laminar boundary layer is stable in a flow with a pressure drop and unstable in a flow with a pressure rise. Focusing on the fact that if there is a pressure drop, laminar flow is easily maintained in that portion, we have proposed a propeller for a ship that can solve the above problems.

If the laminar flow is maintained on the surface of the propeller blade, the drag force acting on the propeller blade is reduced and the lift force is increased to increase the propeller thrust.

Means for Solving Problems In order to solve the above problems, the marine propeller of the present invention is
A plurality of slits are formed on the surface of the propeller blade from near the center of the front and rear edges of the propeller blade to near the trailing edge, from the vicinity of the boss portion to the vicinity of the tip of the propeller blade, and the propellers corresponding to these slits are formed. A suction pipe for sucking seawater from the slit is arranged inside the wing, and a suction device for sucking seawater into the hull through the suction pipe and discharging the seawater to the outside of the hull is provided.

Action When the suction device is operated during propulsion of the ship, seawater is sucked from the propeller blade surface, and the laminarization of the flow on the propeller blade surface is promoted.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. (1) is a propeller attached to the rear of the hull (2),
On both sides of each propeller blade (3) and from the center of the front and rear edges of the propeller blade (3) toward the trailing edge, from the vicinity of the propeller boss (1a) to the vicinity of the outer periphery of the propeller blade (3), that is, the tip. A plurality of slits (4), for example, three slits (of course, four slits or more) may be formed in the vicinity. Then, inside the propeller blades (3) corresponding to these slits (4), a suction pipe (5) for sucking seawater from the slits (4) is arranged, and seawater is hulled through this suction pipe (5) ( There is provided a suction device (6) for sucking into the inside of 2) and then discharging to the outside of the hull (2). The suction pipe (5) is fixed inside the propeller blade (3) and the slit (4) as shown in FIGS. 4 and 5.
An outer cylinder (8) having the same shape as that of the above and a notch (7) formed at a position corresponding to the slit (4), and an appropriate width (seawater) through the spacer (9) in the outer cylinder (8). It is fixed with a gap (a) (depending on the suction amount of) and the slit (4) is
An inner cylinder (11) having a plurality of inlets (10) formed vertically at 80 ° symmetrical positions, and seawater sucked into the inner cylinder (11) to the outer peripheral end of the propeller boss (1a). Formed annular step (1
It is composed of a water guide hole (13) leading to the outer peripheral surface of 2). The water guide hole (13) is provided for each propeller blade (3), so that the three inner cylinders (11) are grouped together and connected to one water guide hole (13). The suction device (6) is a suction pump (14) arranged in the hull (2), and is projecting from the rear part of the hull (2) to the outer peripheral side of the annular step (12) of the propeller boss (1a). The annular groove (16) formed on the inner peripheral surface of the annular protrusion (15) and the suction pump (1
4) connecting pipe (17) and the discharge pipe (1) for discharging the seawater sucked by the suction pump (14) to the outside of the hull (2).
It is composed of 8) and. The propeller (1) side and the hull
Since the suction passage to the (2) side is communicated with the water guide hole (13) and the annular groove (16), there is no problem even when the propeller (1) is rotating. A sealant (not shown) is provided between the annular projection (15) and the annular step (12) on both sides of the annular groove (16).

Therefore, in the above configuration, the suction pump is used when the ship is propelled.
When (14) is operated, as shown by the arrow in FIG. 5, seawater enters the inner cylinder (11) through the slit (4) and the notch (7),
Then, after being introduced into the hull (2) through the water guide hole (13), the annular groove (16) and the contact pipe (17), it is discharged from the hull (2) through the discharge pipe (18). As described above, since seawater is sucked from the surface of the propeller blade (3), the laminarization of the boundary layer on the blade surface is promoted, and the frictional resistance acting on the propeller blade (3) is greatly reduced. In particular, since the slit (4) is provided on the trailing edge side of the propeller blade (3) surface, the portion that is normally the turbulent boundary layer region becomes the laminar boundary layer region, so that the effect is remarkable.

By the way, in the above embodiment, three suction pipes arranged in each propeller blade were connected to one water guiding hole, but each suction pipe sucks seawater through separate water guiding holes and connecting pipes, The slit used is the current engine output,
It may be selected by computer control based on the ship speed and the wake distribution to obtain the best propeller efficiency.

Effects of the Invention According to the configuration of the present invention described above, the region of the laminar boundary layer on the surface of the propeller blade, particularly from the vicinity of the center of the front and rear edges to the portion near the trailing edge, is expanded, and therefore the propeller propelling efficiency is improved.

[Brief description of drawings]

The drawings illustrate one embodiment of the present invention. FIG. 1 is an overall side view, FIG. 2 is a view taken along the line II of FIG. 1, and FIG. 3 is a view taken along the line II-II of FIG. 4 and 5 are enlarged cutaway perspective views of the suction pipe, FIG. 5 is a view on arrow III-III of FIG. 4, and FIG. 6 is an enlarged sectional view of the suction device. (1)… Propeller, (1a)… Propeller Boss section, (2)… Hull,
(3) ... Propeller blade, (4) ... Slit, (5) ... Suction tube, (6) ...
Suction device, (7) ... notch, (8) ... outer cylinder, (10) ... suction port,
(11) ... Inner cylinder, (12) ... Annular step, (13) ... Guide suction hole, (14) ...
Suction pump, (15) ... annular projection, (16) ... annular groove, (17) ... connecting pipe

Front page continuation (72) Takeshi Kato 1-6-14 Edobori, Nishi-ku, Osaka City, Osaka Prefecture Hitachi Shipbuilding Co., Ltd. (72) Masami Hikino 1-6-14 Edobori, Nishi-ku, Osaka City, Osaka Hitachi Zosen Corporation In the company

Claims (1)

[Scope of utility model registration request] 1. A plurality of slits are formed on the surface of a propeller blade, from the vicinity of the center of the front and rear edges of the propeller blade to the portion near the trailing edge, from the vicinity of the boss portion to the vicinity of the tip end portion of the propeller blade. Inside the propeller blades corresponding to the slit, a suction pipe for sucking seawater from the slit is arranged, and after the seawater is sucked into the hull through the suction pipe, a suction device for discharging it outside the hull is provided. Propellers for ships.