JPS6126160Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a propeller shaft housing cooling device for a jet prop type outboard motor.

The jetprop type outboard motor is indicated by arrow A in Figure 1.
As shown in , since the high-temperature exhaust gas from the engine passes around the propeller shaft housing 1 and is discharged from the propeller part 2, the propeller shaft housing 1, propeller shaft 3, bearing 4, and oil seal 5 become hot, and in some cases, In this case, the bearing 4 and the oil seal 5 are damaged, resulting in a situation where the bearing 4 and the oil seal 5 cannot perform their functions.

Therefore, conventionally, for example, a water intake port 8 is opened at the rear end of the gear case 6 located behind the upper part of the propeller 7, and water pushed out by the thrust of the propeller 7 is absorbed through the water intake port 8, and a water intake port 8 is provided inside the gear case 6. Cooling water can be supplied from part B into the exhaust passage 10 via the water suction passage 9, or cooling water flowing around the drive shaft housing 11 can be fed into the exhaust passage 10 from part C by making a hole in a part of the wall. The method of supply was used.

However, the above conventional method has the following disadvantages.

(1) Since the cooling water supplied into the exhaust gas is vaporized,
Although the exhaust temperature can be lowered, the cooling effect of the propeller shaft housing 1, which is directly exposed to the exhaust gas, is insufficient, and the bearing 4 and oil seal 5 may still be damaged due to high temperatures.

(2) The water absorption passage 9 provided inside the gear case complicates the shape of the gear case 6.

(3) The generation of water vapor in the exhaust passage 10 causes a decrease in exhaust efficiency, leading to a decrease in engine output.

In view of the above circumstances, an object of the present invention is to provide a propeller shaft housing cooling device for an outboard motor that can sufficiently cool the propeller shaft housing without complicating the shape of the gear case or reducing engine output. The gist is that a cooling water passage is formed in the outer wall of the outboard motor near the main part of the propeller shaft housing, and water outside the outer wall is guided to the outside of the main part of the propeller shaft housing through the passage. A propeller shaft housing cooling device for an outboard motor is characterized by the following features:

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.

FIGS. 2 and 3 are conceptual cross-sectional views of essential parts showing an embodiment of the cooling device according to the present invention.

The figure corresponds to the arrow D portion in FIG.
1b is connected to the main portion 1a via a rib 1c,
The outer housing portion is located between the gear case 6 and the propeller portion 2 and forms part of the outer wall of the outboard motor. In this embodiment, the housing main portion 1a
A nearby outer wall of the outboard motor (a wall facing water outside the outboard motor, such as seawater; in FIGS. 2 and 3, the gear case 6, the outer housing portion 1b, and the propeller portion 2 constitute the outer wall). ), and a cooling water passage 12 is formed in this outer part 1b.

The cooling water passage 12 has an inlet opening end facing the sea outside the outer part 1b, and a discharge opening end passing through the housing rib 1c and the housing main part 1a onto the main part 1a, especially the bearing 4 and the oil seal 5. It is opened near the. In the case of this embodiment, for example, as shown in FIG. 3, which is a conceptual diagram of the propeller shaft housing 1 viewed from the direction of arrow E in FIG. , it is also possible to further enhance the cooling effect.

In the case of FIGS. 2 and 3, not only one passage 12 but also a plurality of passages 12 may be formed as appropriate, and the passage 12 may have a plurality of introduction opening ends or discharge opening ends.

Since the cooling device according to the present invention is constructed as described above, water from outside the outer wall of the outboard motor, such as seawater, is directly introduced and passed through the interior of the main part 1a of the propeller shaft housing, particularly at the exhaust gas outlet of the main part 1a. Since it can be guided onto the housing main part 1a at the end where the bearing 4 and oil seal 5 are located, a sufficient cooling effect can be expected.

In this case, since the seawater at the end of the introduction opening of the passage 12 is at high pressure due to the rotation of the propeller, sufficient cooling water can be introduced, and the main part of the cooling water housing 1
Since it is introduced into the main portion 1a through the inside of the fuel cell 1a, it will not be vaporized and there is no risk of reducing the output of the engine.

In the present invention, it is preferable that the outer wall of the outboard motor near the main portion of the propeller shaft housing be made of something other than the gear case 6. In the case of an outer wall other than the gear case 6, cooling water is inevitably introduced into the exhaust gas outlet end of the main part of the propeller shaft housing where the bearing 4 and oil seal 5 are located, and the introduction opening end of the passage. This is convenient because the seawater in the area is also under high pressure.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional conceptual diagram showing a conventional cooling device, Fig. 2 is a cross-sectional conceptual diagram showing an embodiment of the present invention, and Fig. 3 is a conceptual diagram of the propeller shaft housing shown in Fig. 2, viewed from the direction of arrow E. It is a diagram. 1...Propeller shaft housing, 1a...Housing main part, 1b...Housing outer part, 1b,
2, 6...outboard motor outer wall, 12...cooling water passage.

Claims (1)

[Scope of utility model registration request] In a propeller shaft housing cooling system for an outboard motor, which has a propeller shaft housing in which the main housing part that supports the propeller shaft and the outer housing part that constitutes a part of the outer wall of the outboard motor are connected via ribs, the cooling water A propeller shaft housing cooling device for an outboard motor, characterized in that an introduction opening end of the passage is opened at the outer side of the housing, and a discharge opening end is opened at the outer surface of the housing main part through a rib and the housing main part.