JP3132950B2 - Stern bearing for contra-rotating propeller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventionally, in a contra-rotating propeller propulsion device for a ship, as shown in FIG. 4, an inner shaft 02 having a rear propeller 01 at a tip end via a reversing device by a motor such as a diesel engine (not shown). And a hollow outer shaft 04 having a front propeller 03 at the tip are coaxially rotated in opposite directions to obtain a propulsion force. To support these two propeller shafts, the outer shaft 04 and the hull 05
The outer shaft support bearings 06 and 07 are required between
It is required inner shaft support bearing 08, 09 between the inner shaft 02 and outer shaft 04. Also, stern seals 010 and 011 are provided to prevent leakage of lubricating oil. Outer shaft support bearing 06, 07 is the same action as the conventional stern tube bearing, particularly, though not technical difficulties, the inner shaft support bearing 08, 09, opposite <br/> the bearing and the shaft to each other Because it rotates in the direction, the operation is different from that of the normal stern tube bearing. In this case, with a perfect circular plain bearing,
Fluid lubrication load capacity decreases. As a means for solving this problem, a structure disclosed in Japanese Patent Application No. 60-250471 has been proposed. The present invention relates to an improvement of the present invention. That is, in FIG. 5, the inner shaft bearing 09 is integrally fitted to the front propeller boss 03. The inner shaft 02 is provided with a lubrication hole 012 on the center line thereof, and a plurality of radial lubrication holes 01 is provided at a position facing the inner shaft bearing 09.
3 and each oil supply hole 013 has an orifice 0
High pressure oil is ejected to the bearing surface of the inner shaft bearing 09 via the bearing 14 to generate a hydrostatic bearing effect. The inner shaft bearing material 99-1 is a metal bearing using white metal in an oil lubricated bearing.

[0003]

However, this type of bearing has the following problems. That is, the inner axis 0
2 is bent by the weight of the rear propeller and the fluid force acting on the propeller. Also, the inner shaft bearing 09 is
The stored front propeller boss 03 also undergoes bending deformation due to its own weight and fluid force acting on the propeller. As a result,
In the inner shaft bearing 09, the inner shaft 02 is tilted, and the bearing load capacity is greatly reduced as compared with the case where there is no tilt. In particular, in the contra-rotating propeller, since the fluid force acting on the propeller has a different rotation direction, the rear propeller and the front propeller have opposite directions, and the inclination of the inner shaft 02 relative to the inner shaft bearing 09 is The bearing is further enlarged, and the bearing and the shaft come into contact with each other, which easily causes seizure damage. In order to prevent this damage, it is necessary to increase the diameter of the inner shaft 02 and the outer shaft 04 to reduce the bending, and to increase the pressure of the lubricating oil supplied to the oil supply hole 012 . The drawbacks associated with these are summarized as follows. (1) Increasing the diameter of the inner and outer shafts increases the diameter of the seal, lowers the reliability of the seal, and increases the cost. (2) Supplying high-pressure oil increases power consumption of the oil supply pump. Oil tanks are required to have great pressure resistance,
High cost. (3) release speed of the bearing surface of the high-pressure oil is quickly no longer, erosion wear of the white metal is likely to occur.

[0004] The present invention has been proposed in view of such circumstances, and even if the relative inclination between the inner shaft and the outer shaft or the relative inclination between the inner shaft and the front propeller boss is large, the diameter of the inner and outer shafts is reduced. It is an object of the present invention to provide an economical contra-rotating propeller stern bearing that prevents a decrease in bearing load capacity without increasing the size and lubricating oil pressure.

[0005]

Means for Solving the Problems To solve the above problems,
Therefore, the stern bearing for the contra-rotating propeller of the present invention, the inner shaft having the rear propeller at the tip is inserted into the center hole of the hollow outer shaft having the front propeller at the tip, and both shafts are coaxially opposed to each other. a bearings <br/> for counter-rotating propeller to rotate, high pressure oil via a sliding bearing to the inner shaft rotatably supported in the outer shaft, it is fed through the center hole of the inner shaft Within
Up through multiple oil holes radially drilled in the radial direction of the shaft
In those is supplied to the serial sliding bearing, the outer peripheral surface on the center hole inner surface or is fitted to the outer shaft rear near the inner surface large diameter cylindrical back metal and the inner circumferential surface of the front propeller boss
A small-diameter cylindrical portion made of a polymer material such as rubber and having an inner shaft inserted therein and an outer peripheral surface integrally fitted to the inner surface of the back metal.
Internal and or axially parallel to one another formed by <br/> equal intervals in the circumferential direction on the interface between the back metal of the cylindrical body and said small-diameter cylindrical portion of the two-layer structure constituted by the And a through oil hole.

[0006]

[Action] According to such a configuration, the front Puroperabo scan
When the inner shaft is relatively inclined, the bearing of the present invention has an effect that the bearing surface is deformed along the inner shaft, and the relative inclination between the bearing and the inner shaft is reduced. When the inner shaft is inclined relatively to the bearing, the oil film thickness in the axial direction is not uniform, and the oil film thickness at one bearing end is thin. Where the oil film thickness is small, a large oil pressure is generated on the bearing surface. Due to the generated hydraulic pressure, the rubber or polymer bearing surface is subjected to compressive deformation due to a low elastic modulus, and the relative inclination angle between the shaft and the bearing surface is reduced. For this reason, a large static pressure distribution is secured over a wide range in the axial direction, and a decrease in bearing load capacity is smaller than that of a rigid metal bearing. In this manner, seizure damage due to one-side contact is less likely to occur.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view showing an inner shaft bearing portion, and FIG.
3 is an explanatory view showing the operation and effect of the inner shaft bearing when the inner shaft is inclined in FIG.

In FIGS. 1 to 3 , the reference numerals in FIG. 4 and FIG. 5 in which 0 is omitted indicate the same members as those in FIG. 4 and 5 is that the material of the bearing member in contact with the inner shaft is made of a polymer material represented by rubber instead of white metal. The point is that a large number of axial through-holes are provided in order to make the material easily deformable and to remove heat generated inside the polymer material due to hysteresis deformation.

That is, as shown in FIGS. 1 and 2,
The inner shaft bearing 9 has a double structure, and the back metal 9-
A small-diameter cylindrical portion 9-2 made of rubber or a polymer material is fixed to the inner surface of the third member 3 by molding or the like. Come together the back metal 9-3 and the small-diameter cylindrical portion 9-2, and is fixed by press-fitting or the like to the propeller boss 3. The small-diameter cylindrical portion 9-2 made of a rubber layer or a polymer layer is more juxtaposed axial through oil holes 15 at equal intervals in the circumferential direction of the oil discharge holes extending in the axial direction. Although the axial through- hole 15 is provided at the interface with the back metal 9-3 in FIG.
It may be provided in a layer <br/> inside the small-diameter cylindrical portion 9-2 of the rubber layer or a polymer layer. In order to make oil drainage smoother, an oil drainage groove 16 penetrating in the axial direction is also provided on the outer peripheral surface of the back metal 9-3. The small-diameter cylindrical portion 9-2
On the surface (bearing surface) of (1), a well-known axial groove of a water-lubricated stern tube rubber bearing is not provided, and the surface has a circular cross-sectional shape.

In such an inner shaft bearing structure, FIG.
As shown, the inner shaft 2 is relative to the propeller boss 3
When tilted to the inner shaft 2Small diameter cylindrical part of inner shaft bearing 99-2
WhenCaused a rammingTryingYou. This pieceProduce
Try toWhere the pressure of the lubricating oil exiting the orifice 14
Will be higher. This high-pressure oil has a rubber layer that is a low elastic body
Is the polymer layerSmall diameter cylindrical part as9-2 is compressed and deformed,
IllustratedofIt deforms like part B, preventing one-sided contact.
As a result, inner shaft 2 and part BWhenAre almost parallel, so this
In this part, almost uniform static pressure is maintained in the axial direction, and the static
The pressure lubrication load capacity is obtained when there is almost no deformation of the bearing (in the figure,
This is greatly improved as compared with (dashed line). Because of this,
Can prevent seizure damageNanaYou. Also axial penetrationOil passing
Hole 15By providingThe following effects are obtained.
Lubricating oil discharged from the bearingAxial penetrationThrough oil hole 15
So that the rubber layerSmall-diameter cylindrical part consisting of9-
Remove the heat generated by the repeated deformation of 2,Small diameter cylindrical part9
-2 to suppress the temperature rise, ThatDeteriorationButPreventionIs
You. Axial penetrationoilRubber layer due to holes 15Such
Small diameter cylindrical part9-2 can be easily compressed and deformed.
It is effective for hit prevention.Axial directionPenetratingoilHole 15 is
Circumferential directionToSince a plurality are provided at equal intervals, after deformation
Deviates from a perfect circular shape. With reversing plain bearings
Is different from a plain bearing in that it has a dynamic fluid lubrication load capacity
Is smaller when the shape of the bearing surface is a perfect circle.
If it deviates from a perfect circle, the dynamic fluid lubrication load
Ability to improve. Therefore,Axial directionPenetrating
oilBy hole 15R, In addition to hydrostatic lubrication, dynamic pressure fluid
A lubricating action can also be exerted.

[0011]

According to the inner shaft bearing having such a structure, the following effects can be obtained as compared with the conventional metal bearing. (1) the magnitude seizure resistance against uneven contact Kunar. (2) It is possible to reduce the lubrication pressure compared to conventional bearings. (3) It is particularly suitable for a large output contra-rotating propeller inner shaft bearing in which one-sided contact due to the propeller force becomes remarkable. (4) The bearing of the present invention can be provided on the inner surface near the rear portion of the outer shaft. In short, according to the present invention, a contra-rotating propeller in which an inner shaft having a rear propeller at a tip is inserted into a center hole of a hollow outer shaft having a front propeller at a tip, and both shafts are coaxially rotated in opposite directions to each other. a bearings for the upper
Via the sliding bearing the serial inner shaft rotatably supported in the outer shaft, through a plurality of oil holes a high-pressure oil supplied through a central hole drilled radially in the radial direction of the inner shaft of the inner shaft in that then supplied to the sliding bearing, the outer peripheral surface of the inner shaft interpolation the center hole inner surface or is fitted to the outer shaft rear near the inner surface large diameter cylindrical back metal and the inner circumferential surface of the front propeller boss is the outer circumferential surface is composed of a small-diameter cylindrical portion made of rubber or the like polymeric material is integrally fitted to the inner surface of the back metal
And a cylindrical body having a two-layer structure, and the inside of the small-diameter cylindrical portion and / or
By equipped with the axial through oil holes parallel plurality of mutually formed at equal intervals in the circumferential direction on the interface between the back metal, the relative inclination between the inner shaft and the outer shaft or the inner shaft, and Even if the relative inclination with respect to the front propeller boss is large, an economical contra-rotating propeller stern bearing that prevents a decrease in bearing load capacity without increasing the inner and outer shaft diameters and without increasing the lubricating oil pressure is obtained. The present invention is extremely useful in industry.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an inner shaft bearing portion showing one embodiment of the present invention.

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

FIG. 3 is an explanatory view showing the operation and effect of the inner shaft bearing when the inner shaft is inclined in FIG.

FIG. 4 is a side view showing a bearing portion of a conventional contra-rotating propeller shaft.

FIG. 5 is an enlarged view showing the inner shaft bearing of FIG.

[Explanation of symbols]

Reference Signs List 1 rear propeller 2 inner shaft 3 front propeller (front propeller boss) 4 outer shaft 5 hull 6,7 outer shaft support bearing 8 inner shaft front bearing 9 inner shaft rear bearing 9-1 white metal 9-2 rubber or polymer Small-diameter cylindrical portion 9-3 composed of layers Back metal 10, 11 Stern seal 12 Inner shaft oil supply hole 13 Radial oil supply hole 14 Orifice 15 Axial through oil hole 16 Oil drain groove

Continuation of front page (56) References JP-A-62-110595 (JP, A) JP-A-5-126138 (JP, A) JP-A-3-85722 (JP, U) JP-A-62-36900 (JP, A) , U) Shokai Sho 57-12824 (JP, U) JP-B 48-18965 (JP, B1) JP-B 48-18403 (JP, B1) (58) Fields surveyed (Int. Cl. ⁷ , DB Name) B63H 23/36 B63H 5/10 F16C 17/00

Claims (1)

(57) [Claims] 1. A interpolates inner shaft having a rear propeller at the tip in the central hole of the hollow outer shaft having a front propeller on the tip, for counter-rotating propeller which coaxially rotate both axes in opposite directions a of bearings, via a sliding bearing to the inner shaft rotatably supported in the outer shaft, is drilled radially in the radial direction of the inner shaft high-pressure oil supplied through the center hole of the inner shaft The bearing is supplied to the above-mentioned plain bearing through a plurality of oil holes.
Rubber height outer circumferential surface the inner shaft is inserted into the large-diameter cylindrical back metal and the inner circumferential surface is integrally fitted to the inner surface of the back metal which is fitted into the hole inner surface or the outer shaft rear near the inner surface and the cylindrical body of the two-layer structure constituted by a small-diameter cylindrical portion formed of a molecular material, a plurality of parallel formed at equal intervals in the circumferential direction on the interface between the inner and or the back metal of the small-diameter cylindrical portion A stern bearing for a contra-rotating propeller, comprising: