JPH0930496A - Bearing device for double reversing propeller shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an inside propeller shaft from the addition of the mass of a front propeller for preventing a usable rotary region from the vibrational trouble caused by a resonance phenomenon, while preventing a casing from the expansion and improving the reliability of a double reversing bearing. SOLUTION: The front end side of a double reversing propeller shaft 7 consisting of an outside propeller shaft 5 and inside propeller shaft 6 disposed concentrically is housed in a casing 4 and supported respectively through bearings 23, 24. Bevel gear 13 on the lower end of a vertical shaft 12 meshes with bevel gears 10, 11 on the respective front ends of outside and inside propeller shafts 5, 6. A double reversing bearing 21 is provided at the rear side of an annular space 20 between the outside and inside propeller shafts 5, 6. The front end of the outside propeller shaft 5 is extended up to the intermediate position of the bevel gears 10, 11. The extension part 5a is supported by a bearing 28 provided between the bevel gears 10, 11 in the casing 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contra-rotating propeller shaft bearing device for use in a marine propulsion device equipped with a contra-rotating propeller capable of improving the propulsion performance of a marine vessel.

[0002]

2. Description of the Related Art A marine propulsion device equipped with a contra-rotating propeller has an outer propeller shaft having a front propeller attached to its rear end and an inner propeller shaft having a rear propeller attached to its rear end concentrically. The bevel gear at the lower end of the vertical shaft connected to the engine is meshed with the bevel gear fixed to the front end of the outer propeller shaft and the front end of the inner propeller shaft, respectively, and the front and rear propellers are mutually driven by the power from the main engine. Although the boat is propelled by rotating it in the opposite direction, in recent years, it is possible to change the propulsion direction of the boat by horizontally turning the boat propulsion device equipped with such a counter-rotating propeller. A so-called full swing type ship propulsion device has been proposed. Now, as an example, showing a full-turn type counter-rotating propeller propulsion device,
As shown schematically in FIG. 2, struts 3 are arranged vertically on the stern of the ship 1 and have upper ends rotatably supported by bearings 2.
Fix the casing (propeller pot) 4 at the lower end of
Inside the casing 4, a contra-rotating propeller shaft 7 formed by concentrically inserting an inner propeller shaft 6 into a hollow outer propeller shaft 5 is rotatably housed, and the outer propeller shaft 5 and the inner propeller are rotatably housed. The front propeller 8 and the rear propeller 9 are attached to the rear ends of the shafts 6, respectively, and the helical bevel gears 10 and 11 attached to the front ends of the outer propeller shaft 5 and the inner propeller shaft 6 so as to face each other are attached to the inside of the strut 3. Is engaged with a helical bevel gear 13 attached to the lower end of a vertical shaft 12 which is rotatably supported by the ship, and the upper end of the vertical shaft 12 is engaged with the ship 1.
By connecting the power from the main engine 15 to the vertical shaft 12 via the intermediate shaft 16 and the drive mechanism 14 by connecting to the drive mechanism 14 provided inside, through the outer propeller shaft 5 and the inner propeller shaft 6 described above. The front propeller 8 and the rear propeller 9 are rotationally driven in opposite directions, and the ring gear 17 fixed to the upper end of the strut 3 is meshed with the gear 19 of the drive device 18 fixed to the hull side. The front and rear propellers 8 and 9 can be horizontally swung by rotating the strut 3 by the drive device 18.

A conventional counter-rotating propeller shaft bearing device used in a ship propulsion apparatus equipped with the counter-rotating propeller having the above-described structure has the structure shown in FIG. 3 and FIG. There is a configuration shown. In FIG. 3, a counter rotating bearing 21 is interposed in an annular space 20 between the inner surface of the rear end portion of the outer propeller shaft 5 and the outer surface of the inner propeller shaft 6 arranged concentrically, and the outer propeller shaft 5 5 and the front end portion of the inner propeller shaft 6 to the bearings 23 and 2 respectively.
4, the counterpropelling bearing 22 is provided between the inner surface of the front end portion of the outer propeller shaft 5 and the outer surface of the inner propeller shaft 6, so that the outer propeller shaft 5 is attached to the inner propeller shaft 6. The two counter rotating bearings 21 and 22 are used to hold the bearings. In the figure, 25 is a sealing device between the casing 4 and the outer propeller shaft 5, and 26 is a counter-rotating sealing device between the outer propeller shaft 5 and the inner propeller shaft 6.

Further, in the structure shown in FIG. 4, a counter rotating bearing 21 is interposed in an annular space 20 between the inner surface of the rear end portion of the outer propeller shaft 5 and the outer surface of the inner propeller shaft 6 which are concentrically arranged. And the front end side of the outer propeller shaft 5 and the inner propeller shaft 6
In a configuration in which the front end portions of the above are supported by the casing 4 by bearings 23 and 24 respectively, another bearing 27 is provided near the rear side of the helical bevel gear 10 attached to the front end of the outer propeller shaft 5, 27 is fixedly supported inside the casing 4, and the outer periphery of the outer propeller shaft 5 is rotatably supported by two bearings 23 and 27. In addition,
4, the same components as those in FIG. 3 are designated by the same reference numerals.

[0005]

However, in the case of the conventional counter-rotating propeller shaft bearing device used in the ship propulsion apparatus equipped with the counter-rotating propeller shown in FIG. Since only one bearing 23 is provided near the center on the outer circumference, the outer propeller shaft 5 is inclined along the inner propeller shaft 6,
The flexural vibration of the shaft system is governed by the bending rigidity of the inner propeller shaft 6, but the inner diameter propeller shaft 6 has a smaller diameter and lower rigidity than the outer propeller shaft 5, and the front propeller 8 and the rear propeller 9 are also small. Since both masses are added, the natural frequency of the flexural vibration of the shaft system due to the rotational driving force becomes low, which may cause a resonance phenomenon in the operating rotation range and damage the hull or shaft system. Further, since the front and rear counter rotating bearings 21 and 22 arranged in the annular space 20 hold the outer propeller shaft 5 and the inner propeller shaft 6 to each other, the front and rear counter rotating bearings 21 Lubricating oil for lubricating the rear and counter rotating shafts is confined within a range sandwiched between the front and rear counter rotating bearings 21 and 22 between the outer propeller shaft 5 and the inner propeller shaft 6, and the rear counter rotating bearings. 21 new lubricating oil arrives When the seawater leaks from the gap of the counter-rotating seal device 26, the deteriorated and contaminated lubricating oil is likely to stay, and the bearing may be damaged. 21 There is a problem that the surrounding lubricating oil may be contaminated.

Further, in the case of the bearing device of the contra-rotating propeller shaft shown in FIG. 4, the outer periphery of the outer propeller shaft 5 is supported by the casing 4 via the bearings 23 and 27 at the front and rear, so that the front propeller is supported. Since the mass of No. 8 is prevented from being added to the inner propeller shaft 6 and the counter rotating bearing 22 on the front side in FIG. 3 is abolished, the problem in that shown in FIG. Since 23 and 27 are provided on the rear side of the bevel gear 10, it is necessary to secure an appropriate span s between the two bearings 23 and 27 inside the casing 4, and the casing 4 itself becomes large. There is a problem that it will end up.

Therefore, according to the present invention, the mass of the front propeller is prevented from being added to the inner propeller shaft, and further, the lengthening of the casing can be prevented. Furthermore, the rear side between the outer propeller shaft and the inner propeller shaft is prevented. Another object of the present invention is to provide a bearing device for a counter-rotating propeller shaft used in a ship propulsion device equipped with a counter-rotating propeller, which makes it easier to supply new oil to the counter-rotating bearing.

[0008]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention concentrically arranges an inner propeller shaft having a rear propeller attached to a rear end into a hollow outer propeller shaft having a front propeller attached to a rear end. The front end side of the contra-rotating propeller shaft, which is formed by inserting a bearing between the inner surface of the rear end of the outer propeller shaft and the inner propeller shaft, is housed in the casing. The bevel gear fixed to the front end of the outer propeller shaft and the front end of the inner propeller shaft, respectively, is fixed to the bevel gear fixed to the lower end of the vertical shaft. The counter-rotating propellers are engaged with each other and the front propeller and the rear propeller are rotationally driven in opposite directions via the outer propeller shaft and the inner propeller shaft by the driving force transmitted through the vertical shaft. The front end portion of the outer propeller shaft in the marine vessel propulsion apparatus provided with a ra is extended to an intermediate position between the two bevel gears fixed respectively to the front end portion of the outer propeller shaft and the front end portion of the inner propeller shaft, and the extension is performed. The outside of the front end portion of the outer propeller shaft is rotatably supported by a bearing fixed in the casing.

The front end of the outer propeller shaft is extended to an intermediate position between two bevel gears fixed to the front ends of the outer propeller shaft and the inner propeller shaft, respectively, and the outer propeller shaft is supported by the casing at two positions near the extension and the center. If it is rotatably supported through the casing, the casing can receive all the loads related to the outer propeller shaft, such as the weight of the outer propeller shaft and the load of the front propeller attached to the rear end. Since the shaft needs to hold only the load of the propeller after being attached to the rear end, it is possible to sufficiently increase the natural frequency of the flexural vibration of the shaft system due to the rotational drive. Further, the annular space between the inner surface of the outer propeller shaft and the outer surface of the inner propeller shaft is provided with only the counter rotating bearing on the rear side, and the counter rotating bearing on the front side is eliminated. Since the rear counter rotating bearing is communicated with the rear counter rotating bearing, new lubricating oil can be supplied to the rear counter rotating bearing. Further, a bearing provided on the extension of the front end of the outer propeller shaft is located at an intermediate position between the bevel gears fixed to the front end of the outer propeller shaft and the front end of the inner propeller shaft, that is, below the bevel gear at the lower end of the vertical shaft. Since the large empty space is effectively used for the installation, it is possible to prevent the casing from being enlarged due to the installation of the bearing.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, and is applied as a bearing device of a counter-rotating propeller shaft of a full swing type ship propulsion device equipped with a counter-rotating propeller as shown in FIG. Indicates. Similar to that shown in FIG. 3 or 4, inside the casing 4 (propeller pot) fixed to the lower end of the strut 3 whose upper end is rotatably supported by the stern of the hull, into the hollow outer propeller shaft 5. The front end side of the counter-rotating propeller shaft 7 is formed by inserting the inner propeller shaft 6 concentrically and interposing the counter-rotating bearing 21 between the inner surface of the rear end portion of the outer propeller shaft 5 and the outer surface of the inner propeller shaft. The front end of the outer propeller shaft 5 and the front end of the inner propeller shaft 6 are rotatably supported by the casing 4 via bearings 23 and 24, respectively, and the front end of the outer propeller shaft 5 and the inner propeller shaft are housed. The helical bevel gears 10 and 11 each attached to the front end of 6 are meshed with the helical bevel gear 13 attached to the lower end of the vertical shaft 12 bearing-supported in the struts 3, and the Power from the engine Serial vertical axis 12
To the outer and inner propeller shafts 5 and 6, and the front propeller 8 attached to the rear end of the outer propeller shaft 5 and the rear propeller 9 attached to the rear end of the inner propeller shaft 6.
And a helical bevel gear 10 in which the front end of the outer propeller shaft 5 forming the counter-rotating propeller shaft 7 is fixed to the front end of the outer propeller shaft 5. The required length is extended to an intermediate position between the helical bevel gear 11 fixed to the front end portion of the inner propeller shaft 6, and the outer periphery of the extension portion 5a is divided into two helical bevel gears 1.
It is rotatably supported inside the casing 4 through a bearing 28 arranged at an intermediate position between 0 and 11.

In the figure, the same components as those in FIG. 3 or 4 are designated by the same reference numerals.

The front end of the outer propeller shaft 5 is extended by a required length, and the outer periphery of the extension portion 5a is divided into two helical bevel gears 10 and 1.
When the casing 4 is supported by the bearing 28 disposed at an intermediate position with respect to 1, all the loads applied to the outer propeller shaft 5, such as the weight of the outer propeller shaft 5 and the mass of the front propeller 8, are not applied to the outer propeller. The casing 4 is provided with two bearings 23 and 28 that rotatably support the outer periphery of the shaft 5.
Since the inner propeller shaft 6 is supported only by the load of the rear propeller 9 attached to the rear end of the inner propeller shaft 6, the natural frequency of the flexural vibration of the shaft system accompanying the rotational drive is sufficiently increased. It is possible to prevent the trouble of vibration due to the resonance phenomenon in the used rotation range, and
Bearing 28 for supporting extension 5a at the front end of outer propeller shaft 5
Is to be installed in an intermediate position between the two helical bevel gears 10 and 11, that is, in a wide space formed below the helical bevel gear 13 attached to the lower end of the vertical shaft 12. Therefore, the bearing 25 can be efficiently housed inside the casing 4, and the casing 4 does not become large due to the installation of the bearing 28 as shown in FIG. Furthermore, since the counter-rotating bearing 22 as shown in FIG. 3 is omitted on the front side of the annular space 20 between the outer propeller shaft 5 and the inner propeller shaft 6, the front and rear counter-rotating bearings 21 and 22 are used. Lubricating oil is not trapped in the narrowed range, new lubricating oil can be supplied to the counter rotating bearing 19 on the rear side, and bearing damage due to deterioration and contamination of the lubricating oil is also prevented. be able to.

The present invention is not limited to the above-described embodiment. For example, in the above-mentioned embodiment, the bearing of the contra-rotating propeller shaft of the ship propulsion device provided with the full-turn type counter-rotating propeller. Although the device has been exemplified, it is shown that the ship propulsion device having a contra-rotating propeller without a turning mechanism can be similarly adopted, and the case where the helical bevel gears are attached to various places, It is needless to say that a non-helical bevel gear may be used, and various changes may be made without departing from the scope of the present invention.

[0015]

As described above, according to the bearing device for a counter-rotating propeller shaft of the present invention, the front end side of the counter-rotating propeller shaft composed of the outer propeller shaft and the inner propeller shaft that are concentrically arranged is the casing. The bevel gears housed inside and fixed to the front end of each propeller shaft mesh with the bevel gear at the lower end of the vertical shaft, and the front propeller is located at the rear end of the outer propeller shaft and the rear propeller is located at the rear end of the inner propeller shaft. In the configuration in which the front propeller and the rear propeller are rotationally driven in opposite directions via the outer and inner propeller shafts by the driving force transmitted through the respective vertical shafts, the outer propeller shaft and the inner propeller are A counter rotating bearing is arranged only on the rear side of the annular space, and the front end of the outer propeller shaft is extended to the intermediate position between the bevel gears that are fixed to the front ends of the outer and inner propeller shafts. Since the extension of the outer propeller shaft and the two places near the center are supported by the casing through bearings, all the load related to the outer propeller shaft must be supported by the casing through the two bearings. As a result, it is possible to sufficiently increase the natural frequency of flexure of the shaft system, prevent the occurrence of resonance phenomena in the operating rotation range and damage the hull and shaft system, and the front end of the outer propeller shaft. Since the bearing supporting the extended portion of the casing is provided by effectively utilizing the empty space inside the casing, it is possible to prevent the casing from becoming large due to the provision of the bearing, and The annular space between the outer propeller shaft and the inner propeller shaft has only the rear counter-rotating bearing in the annular space, so it is possible to supply new lubricating oil to the rear counter-rotating bearing. It is possible to lengthen the life cycle can improve the reliability of the contra-rotating bearing is a part, there is exhibited an excellent effect that.

[Brief description of drawings]

FIG. 1 is an enlarged view showing an outline of an embodiment of a bearing device for a counter-rotating propeller shaft according to the present invention.

FIG. 2 is an overall view showing a full swing type as an example of a vessel propulsion apparatus equipped with a contra-rotating propeller.

FIG. 3 is an enlarged view showing an outline of an example of a bearing device for a conventional counter-rotating propeller shaft used in a ship propulsion apparatus including the counter-rotating propeller shown in FIG.

FIG. 4 is an enlarged view showing another example of a conventional bearing device for a counter-rotating propeller shaft.

[Explanation of symbols]

 4 casing (propeller pot) 5 outer propeller shaft 5a extension 6 inner propeller shaft 7 counter-rotating propeller shaft 8 front propeller 9 rear propeller 10, 11 helical bevel gear 12 vertical shaft 13 helical bevel gear 20 annular space 21 Counter rotating bearing 23, 24, 28 bearing

Claims (1)

[Claims] Claim: What is claimed is: 1. A hollow outer propeller shaft having a front propeller attached to its rear end, and an inner propeller shaft having a rear propeller attached to its rear end, inserted concentrically into the hollow outer propeller shaft, and a rear end inner surface of the outer propeller shaft and the inner propeller shaft. The front end side of the contra-rotating propeller shaft with a bearing interposed between is housed in the casing, and the vicinity of the center of the outer propeller shaft and the front end of the inner propeller shaft are rotatably supported by the casing via the bearing. Along with the bevel gear fixed to the front end of the outer propeller shaft and the front end of the inner propeller shaft, respectively, the bevel gear fixed to the lower end of the vertical shaft is meshed with the outer propeller shaft by the driving force transmitted through the vertical shaft. Of the outer propeller shaft in a ship propulsion device equipped with a contra-rotating propeller adapted to rotate the front propeller and the rear propeller in opposite directions via the inner propeller shaft. The front end portion is extended to an intermediate position between the two bevel gears fixed to the front end portion of the outer propeller shaft and the front end portion of the inner propeller shaft, respectively, and the front end outer portion of the extended outer propeller shaft is fixed in the casing. A bearing device for a contra-rotating propeller shaft, which is rotatably supported by a bearing.