JPH0740889A - Stern bearing device for counter-rotating propeller - Google Patents

Abstract

PURPOSE:To prevent an increase in feed oil pressure by restraining the deterioration in bearing load capacity even when a relative inclination of an inner shaft to an outer shaft system becomes large in a slide bearing to support the inner shaft particularly on the stern side. CONSTITUTION:In a counter-rotating propeller device to reverse an inner shaft 2 and an outer shaft 4, since a rubber layer 9-2 is arranged in a slide bearing so as to allow tilting of the slide bearing to support the inner shaft 2 on the stern side, even if a relative inclination of the inner shaft 2 to an outer shaft system becomes large, the deterioration of bearing load capacity of the slide bearing can be restrained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stern bearing device applied to a counter rotating propeller device.

[0002]

2. Description of the Related Art FIG. 5 schematically shows a stern bearing device in a contra-rotating propeller device.

In the contra-rotating propeller device, a prime mover (not shown) (such as a diesel engine) is provided with an inner shaft (2) having a rear propeller (1) at a rear end through a reversing device,
The outer shaft (4) having the front propeller (3) at the rear end is reversely rotated, whereby the rotational components in the wake of the propeller are offset to efficiently obtain a propulsion force. In order to drive the inner shaft (2) and the outer shaft (4) smoothly, generally, outer shaft bearings (6, 7) are provided between the outer shaft (4) and the hull (5), and Inner shaft bearings (8, 9) are provided between the inner shaft (2) and the outer shaft (4). In addition, the stern seal (1
0, 11) are provided. The outer shaft bearing (6) operates in the same manner as a normal stern tube bearing, and is not technically difficult, but the inner shaft bearing (8, 9) is fixed to the outer shaft (4) to be fixed to the inner shaft (6). Since it is reverse to that of 2), the operation is different from that of a normal stern tube bearing, and in particular, the sliding bearing as the stern side inner shaft bearing (9) has a problem that the fluid lubrication load capacity becomes small.

As a solution to this problem, the structure shown in FIG. 4 has been proposed. In FIG. 4, the stern side inner shaft bearing (9) is integrally fitted to the front propeller boss (3). The inner shaft (2) is provided with an oil supply hole (12) and communicates with the plurality of radial oil supply holes (13) at a position facing the inner shaft bearing (9). In this way, the high pressure oil is ejected to the bearing surface of the inner shaft bearing (9) through the orifice (14) inside the oil supply hole (13).

[0005]

By the way, in the above-mentioned device, the inner shaft (2) is deflected by the weight of the rear propeller and the fluid force acting on the propeller, and the inner shaft bearing (9) on the stern side is mounted. Built-in forward propeller boss (3)
Also causes a tilt for the same reason, and as a result,
In the inner shaft bearing (9), the inner shaft (2) is largely tilted and the bearing load capacity is reduced, so that the inner shaft bearing (9) and the inner shaft (2)
Contact with and easily cause seizure damage. To prevent this, the pressure of the lubricating oil supplied to the oil supply hole (12) must be increased so that the bearing load capacity can be maintained even if the relative inclination of the inner shaft (2) is large. However, the following drawbacks occur with the high-pressure oil supply. (1) The driving power consumption of the oil supply pump increases. (2) The life of the oil pump is shortened. (3) The reliability of the seal of the oil supply portion for supplying the high pressure oil to the inner shaft (2) is reduced, or the cost of the seal becomes high.

The present invention relates to the stern side inner shaft bearing in the counter-rotating propeller device, even if the relative inclination of the inner shaft with respect to the outer shaft system becomes large, that is, the inclination of the inner shaft with respect to the outer shaft or the forward propeller boss. It is an object of the present invention to provide a stern bearing device for a contra-rotating propeller, which is capable of suppressing a decrease in bearing load capacity even when the inclination of the inner shaft with respect to the shaft is large and which does not require a large refueling pressure. .

[0007]

In the conventional example, the inner shaft bearing is rigidly fitted into the front propeller boss by a method such as cold fitting, whereas in the present invention, the inner shaft bearing outer circumference is fitted. By forming a rubber layer on the surface and interposing an elastic body between the outer circumference of the inner shaft bearing and the propeller boss, or forming a convex curved surface on the outer peripheral surface of the inner shaft bearing, the inner shaft bearing is The structure is such that it can be tilted through a curved surface.

That is, a stern bearing device for a counter-rotating propeller according to the present invention is a counter-rotating propeller device for reversing an inner shaft having a rear propeller and an outer shaft having a front propeller from each other. In order to allow the tilting of the bearing surface of the above slide bearing,
The slide bearing is characterized by having a rubber layer.

Further, in the stern bearing device for a counter-rotating propeller according to the present invention, the slide bearing has an inner peripheral ring having the bearing surface, and a rubber layer provided on the outer periphery of the inner peripheral ring.
It is characterized in that it is composed of an outer peripheral ring provided on the outer periphery of the rubber layer. Further, the stern bearing device for a counter-rotating propeller according to the present invention is characterized in that a plurality of oil grooves penetrating in the axial direction are formed in the rubber layer.

Further, the stern bearing device for a counter-rotating propeller according to the present invention is a counter-rotating propeller device for reversing an inner shaft having a rear propeller and an outer shaft having a front propeller, wherein the inner shaft is stern side. The slide bearing is provided with a support, and a convex curved surface bulging outward is formed on the outer peripheral surface of the slide bearing to allow tilting of the bearing surface of the slide bearing.

[0011]

In the stern bearing device for a counter-rotating propeller according to the present invention described above, when the inner shaft (2) is inclined relative to the outer shaft system, the slide bearing is inclined along the inner shaft, and the slide bearing is inclined. And the relative inclination between the inner axis and the inner axis becomes smaller.

That is, when the inner shaft is inclined relative to the slide bearing, the oil film thickness in the axial direction is not uniform, and the oil film thickness at one bearing end becomes thin. A large oil pressure is generated on the bearing surface when the oil film thickness is small, and a small oil pressure is generated on the bearing surface when the oil film thickness is large. Therefore, in the plain bearing, the tilting of the inner shaft causes a tilting action of the bearing itself depending on the hydraulic pressure between the bearing and the inner shaft. Since the plain bearing has the rubber layer and elastically supports the bearing surface, the bearing surface can be inclined by the deformation of the rubber layer. As a result, the relative inclination between the inner shaft and its bearing surface is smaller than that of the conventional bearing structure that is rigidly supported.

Next, when the outer peripheral surface of the bearing is formed into a convex curved surface, the hydraulic moment acts so that the bearing itself tilts when the inner shaft tilts. Due to this moment, the plain bearing is tilted inside the propeller boss or the like with the convex curved surface as a fulcrum, the inner shaft and the bearing surface are parallel to each other, and the relative tilt is eliminated. This is because, in the case of parallel, the hydraulic pressure in the axial direction becomes uniform, and the moment of inclination disappears.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show a stern bearing device for a counter-rotating propeller as a first embodiment of the present invention. FIG. It is a longitudinal cross-sectional view showing a main part. FIG. 2 shows A of FIG.
FIG. 7 is a cross-sectional view taken along arrow A.

As shown in FIGS. 1 and 2, in the counter-rotating propeller device in which the inner shaft 2 having the rear propeller and the outer shaft 4 having the front propeller are mutually reversed, the inner shaft 2
A slide bearing 9 as an inner shaft bearing for supporting the stern is mounted inside the propeller boss 3 of the forward propeller at the stern.

The inner shaft 2 is provided with a lubrication hole 12, and a plurality of radial lubrication holes are provided at a position facing the plain bearing.
It is in communication with 13. In this way, high pressure oil
It is configured to be jetted to the bearing surface of the slide bearing 9 through an orifice 14 inside 13.

The plain bearing 9 comprises an inner peripheral ring 9-1 having a bearing surface, a rubber layer 9-2 provided on the outer periphery of the inner peripheral ring, and an outer peripheral ring 9-3 provided on the outer periphery of the rubber layer. It is configured. Further, the rubber layer 9-2 is formed with a plurality of oil grooves 9-4 penetrating in the axial direction.

Since the stern bearing device for a counter-rotating propeller according to the first embodiment of the present invention is constructed as described above, when the inner shaft 2 is inclined relative to the propeller boss 3, Due to the hydraulic pressure between the shaft 2 and the inner peripheral ring 9-1 of the slide bearing 9, a moment to tilt along the inner shaft 2 acts on the inner peripheral ring 9-1. Due to this moment, the rubber layer 9-2 is elastically deformed, and the inner peripheral ring 9.1 is inclined. As a result, the relative inclination between the inner shaft 2 and the inner peripheral ring 9-1 becomes small.

In this way, when the relative inclination becomes smaller, the static pressure distribution of the lubricating oil generated on the bearing surface becomes closer to uniform in the axial direction, and the bearing load capacity increases. Therefore, it is possible to prevent damage due to contact (per piece) between the inner shaft 2 and the inner peripheral ring 9-1. Further, as the load capacity is improved, the pressure of the lubricating oil supplied to the supply hole 12 of the inner shaft 2 can be reduced.

The oil groove 9-4 of the rubber layer 9-2 shown in FIG.
The rubber layer 9-2 is encouraged to be deformed and serves as an oil discharge passage from the bearing 9, and the rubber layer 9-2 is repeatedly deformed to cause the same.
-It removes the heat inside 2 and brings about the effect of cooling.

Next, a stern bearing device for a counter-rotating propeller according to a second embodiment of the present invention will be described with reference to FIG.

Also in this second embodiment, in the counter-rotating propeller device for reversing the inner shaft 2 having the rear propeller and the outer shaft 4 having the front propeller, the inner shaft 2 serves as an inner shaft bearing for supporting the stern side. A plain bearing 9 is mounted on the stern of the propeller boss 3 of the forward propeller.

The inner shaft 2 is provided with a lubrication hole 12, and a plurality of radial lubrication holes are provided at a position facing the plain bearing.
It is in communication with 13. In this way, high pressure oil
It is configured to be jetted to the bearing surface of the slide bearing 9 through an orifice 14 inside 13.

In the second embodiment, a convex curved surface 9a bulging outward is formed on the outer peripheral surface of the slide bearing 9 so that tilting of the slide bearing 9 can be allowed especially in the propeller boss 3.
The slide bearing 9 is gently restrained with respect to the propeller boss 3 by a detent 15.

Therefore, when the inner shaft 2 is inclined relative to the propeller boss 3, the contact point position S of the slide bearing 9 changes due to the hydraulic pressure between the inner shaft 2 and the slide bearing 9. It becomes parallel to the inner shaft 2 and there is no relative tilt. Since the relative inclination with the inner shaft 2 is eliminated in this way, a uniform static pressure distribution of the lubricating oil is formed in the axial direction between the inner shaft 2 and the slide bearing 9, and the bearing load capacity is significantly increased. improves. For this reason, the slide bearing 9 has an effect of preventing seizure damage due to partial contact with the inner shaft 2 and reducing the supply hydraulic pressure.

As described above, in any of the first and second embodiments of the present invention, the supply hydraulic pressure can be reduced, so that the driving power consumption of the hydraulic pump can be reduced and the hydraulic pressure can be reduced. This leads to the advantages that the life of the pump can be extended, the lubrication device for the inner shaft can be made compact, and the cost can be reduced.

[0027]

As described in detail above, according to the stern bearing device for a counter-rotating propeller of the present invention, the following effects can be obtained. (1) Regarding the slide bearing for supporting the inner shaft of the counter-rotating propeller device at the stern, the supply oil pressure of the lubricating oil can be reduced. (2) With the above item (1), it is possible to reduce the driving power consumption of the hydraulic pump, which leads to the improvement of the life of the hydraulic pump, the compacting of the supply device for the inner shaft, and the cost reduction. .

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing a main part of a stern bearing device for a counter-rotating propeller according to a first embodiment of the present invention.

2 is a cross-sectional view taken along the line AA of the apparatus of FIG.

FIG. 3 is a longitudinal sectional view showing a main part of a stern bearing device for a counter-rotating propeller according to a second embodiment of the present invention.

FIG. 4 is a vertical cross-sectional view showing a main part of a conventional stern bearing device for a counter-rotating propeller.

FIG. 5 is a vertical cross-sectional view showing a main part of the contra-rotating propeller device.

[Explanation of symbols]

 1 Rear propeller 2 Inner shaft 3 Front propeller 4 Outer shaft 5 Hull 6,7 Outer shaft bearing 8 Inner shaft bearing 9 Stern side inner shaft bearing (sliding bearing) 9-1 Inner ring 9-2 Rubber layer 9-3 Outer ring 9-4 Oil groove 9a Convex curved surface 10, 11 Stern seal 12 Oil supply hole 13 Radial oil supply hole 14 Orifice 15 Non-rotating

Claims (4)

[Claims] 1. A double reversal propeller device for reversing an inner shaft having a rear propeller and an outer shaft having a front propeller, wherein a stern side is provided with a sliding bearing for supporting the inner shaft, and a bearing surface of the sliding bearing is provided. To allow tilting,
The sliding bearing is provided with a rubber layer,
Stern bearing device for counter-rotating propellers. 2. The slide bearing comprises an inner peripheral ring having the bearing surface, a rubber layer provided on the outer periphery of the inner peripheral ring, and an outer peripheral ring provided on the outer periphery of the rubber layer. The stern bearing device for a contra-rotating propeller according to claim 1. 3. The stern bearing device for a counter-rotating propeller according to claim 1, wherein a plurality of oil grooves penetrating in the axial direction are formed in the rubber layer. 4. A double reversal propeller device for reversing an inner shaft having a rear propeller and an outer shaft having a front propeller from each other, comprising a slide bearing supporting the inner shaft on the stern side, and a bearing surface of the slide bearing. To allow tilting,
A stern bearing device for a counter-rotating propeller, wherein a convex curved surface bulging outward is formed on the outer peripheral surface of the slide bearing.