JP2984221B2 - Bearing lubrication structure for counter-rotating marine propellers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing lubricating structure capable of smoothly supplying and circulating lubricating oil to a bearing of a contra-rotating marine propeller.

[0002]

2. Description of the Related Art A contra-rotating marine propeller is a propulsion means for a marine vessel characterized in that two propellers are arranged in front of and behind and inverted (reverse rotation) from each other. FIG. 5 is a longitudinal sectional view showing a portion outside the hull of a conventional marine contra-rotating propeller 51. As shown in FIG.
52 is a hollow outer shaft 70 and an inner shaft 6 passed through the inside thereof.
0, and are rotationally driven in opposite directions by each shaft. The rotational energy loss contained in the wake of the propeller 53 in front is reduced by the rear propeller 5.
2 has the advantages of high propulsion efficiency and low cavitation and hull vibration.

[0003] As a bearing (so-called reversing bearing) 55 for supporting the inner shaft 60 inside the outer shaft 70, there is a so-called hydrostatic bearing in which an oil film is formed between sliding surfaces by supplying lubricating oil from the outside. in use. Hydrostatic bearings are used for the outer shaft 70 and the inner shaft 6 having considerable mass.
0 rotates in the opposite direction at substantially the same speed across the reversing bearing 55, so that it is difficult to form a stable oil film with a general dynamic pressure type bearing used for the bearing 54a for the outer shaft 70 and the like. That's why. Also in the example of FIG. 5, the high-pressure lubricating oil
The oil is sent through an oil supply passage (outgoing oil passage) 82b passing through the inside of the inner shaft 60, and is discharged from an oil supply port 82d facing a gap between the bearing 55 and the inner shaft 60 (that is, between sliding surfaces). An oil film is forcibly formed between the surfaces. The lubricating oil that has flowed out from between the slip surfaces is collected from a return port (not shown) in front (to the right in the figure), returns to a tank (not shown), and is supplied to an oil supply source (not shown) including a pump and the like. ), And the oil is recirculated to the above-mentioned slip surface or the like.

[0004] A shaft sealing means called a reversing seal 73 is provided at a position behind the reversing bearing 55 in order to prevent the lubricating oil from leaking to the outside and to prevent water from entering from outside.
5 (a), a groove 55a shown in FIG. 5 (b) is formed on the outer peripheral surface from the rear end (that is, the side facing the reversal seal) to the front end. Groove 55a
Is a so-called auxiliary circulation for returning the lubricating oil supplied to the reversing bearing 55 flowing toward the stern side (leftward in FIG. 5A) between the slip surfaces to the bow side, as described above. It is an oilway. By providing such an oil passage and allowing the lubricating oil to flow forward, all the lubricating oil can be circulated without stagnation, and excessive pressure can be prevented from being applied to the front surface of the reversing seal 73. The bearing 55 can maintain stable bearing performance. The presence or absence of the oil passage affects the bearing performance if the lubricating oil flows only forward from the oil filler port 82d and does not flow backward, so that the pressure loss due to the flow becomes uneven and the gap between the sliding surfaces This is because a balanced pressure distribution occurs. In addition, such oil passages have conventionally been
It may be formed as a hole that passes through not only the groove 55a but also the thickness of the reversing bearing 55.

[0005] The above technology is disclosed in Japanese Utility Model Publication No. 5-23.
No. 437, for example.

[0006]

As shown in FIG. 5 and the like, forming an auxiliary circulation oil passage by forming a groove in the surface of a reversing bearing or making a hole in the thickness thereof is related to strength. In addition to the disadvantages, it is not convenient for manufacturing.

That is, first, when grooves or holes are formed over the entire length of a reversing bearing, which is the most important mechanical element of a contra-rotating propeller, a bearing having the same external dimensions and no grooves or holes is formed. The strength is somewhat reduced as compared with. Therefore, in order to provide the necessary strength to the bearing, it is necessary to increase the size of the bearing, for example, by increasing the thickness. When the size of the bearing increases, the size of the contra-rotating propeller must be increased as a whole, for example, the outer shaft disposed outside the bearing must be made thicker, resulting in a considerable increase in weight and cost. .

[0008] Second, in order to provide grooves and holes in the axial direction of the reversing bearing in the manufacturing process, apart from machining the inner / outer circumference and the end face of the bearing by using a lathe or the like, the milling machine or drilling machine needs to provide the same. The bearing must be set and new machining must be performed. In general, reversing bearings are quite large and heavy, so adding one step of handling, resetting, and machining between machining devices would add considerable machining costs. Will be raised.

An object of the present invention relates to a contra-rotating propeller for a marine vessel, wherein the auxiliary circulation oil passage for sending the lubricating oil which has reached one end face of the reversal bearing to the other end face close to the return oil passage is provided. An object of the present invention is to provide a lubricating structure formed so as not to cause such strength or manufacturing disadvantages.

[0010]

The bearing lubrication structure for a contra-rotating marine propeller according to claims 1 to 3 differs from the bearing lubrication structure shown in FIG. The first common feature is that it is formed not on the inside of the (reversing bearing) but on the outside (that is, the outer shaft, the propeller boss or the cylindrical member described below) (that is, by providing a groove or a hole in them). Here, the bearing lubrication structure as shown in FIG. 5 means that a bearing (equivalent to a bearing metal or a bearing bush; a reversing bearing) is provided inside a cylindrical outer shaft that drives one of the contra-rotating propellers. ) Is integrated, and an inner shaft for driving the other propeller is passed through the inside of the bearing and is disposed so as to be rotatable relative to the outer shaft. ) And returns to the oil supply source (tank) from the oil passage that leads to the oil supply port facing the gap and sends the lubricating oil to the gap, and the return port that faces the space between the outer shaft and the inner shaft to the oil supply source (tank) A bearing lubrication structure for a marine contra-rotating propeller having a return oil passage. In addition, the auxiliary circulation oil passage means the lubricating oil that has flowed out of the oil supply port of the outgoing oil passage, and has flowed through the gap between the bearing and the inner shaft away from the return opening and has reached one end face of the bearing. Refers to an oil passage for feeding to the other end face side of the bearing (that is, the side close to the return port).

In this structure common to the first to third aspects, when lubricating oil is sent from an oil supply source to an outgoing oil passage, the lubricating oil is
First, the oil is supplied from the oil supply port to between the bearing and the inner shaft (that is, between the slip surfaces) to form an oil film between the slip surfaces. A part of the lubricating oil thus supplied to the slip surface exits from the end face of the bearing near the return port (the bow side in the example of FIG. 5), flows through the space between the outer shaft and the inner shaft, and returns. Return from the mouth to the oil supply tank through the return oil passage. The rest of the lubricating oil supplied to the sliding surface flows away from the return port and reaches the other end of the bearing (the stern side in FIG. 5; the side with the reversing seal). The oil is sent to the end face side near the return port through the auxiliary circulation oil passage formed in a member outside the bearing, and together with other lubricating oil, the space between the outer shaft and the inner shaft and the return oil passage. And return to the tank.

As described above, since the lubricating oil supplied to the sliding surface flows without stagnation in either direction between the sliding surfaces, this bearing lubricating structure has the same structure as the conventional structure shown in FIG. In addition, it is possible to prevent an excessive pressure from being applied to the front surface of the reversing seal and to maintain stable bearing performance in the reversing bearing. If the lubricating oil flows smoothly, the appropriate pressure loss due to the flow will occur in the reversal seal and also in the part of the bearing slip surface far from the return port (the part close to the reversal seal), resulting in partial pressure reduction. This is because it is possible to avoid being excessively large.

However, unlike the conventional bearing lubrication structure,
Since the auxiliary circulation oil passage is formed in a member outside the bearing, this bearing lubrication structure is advantageous in securing mechanical strength around the bearing and manufacturing the bearing.

The reason why mechanical strength is easily ensured is that grooves and holes are not formed in the reversing bearing itself, which is an important mechanical element of the contra-rotating propeller. With such advantages, it is not necessary to increase the bearing dimensions to compensate for mechanical strength and reliability, so that the outer shaft disposed outside can be made thinner than in the past (FIG. 5). Therefore, it is possible to make the contra-rotating propeller smaller overall. This obviously has the effect of reducing the weight of the contra-rotating propeller and reducing the cost.

[0015] The reason for the manufacturing advantage is that, as long as the inner / outer circumference and end face of the bearing are machined by a lathe or the like, the bearing is re-set on a milling machine or a drilling machine, and the auxiliary circulation oil passage ( Grooves, holes, etc.). Auxiliary circulating oil passage is not formed in the bearing is will form to any such outer shaft and the propeller boss instead, grooves or holes in one or more members of them is a lubricating oil passage inversion seal Therefore, if the workpiece to be provided with the auxiliary circulation oil passage is appropriately selected, the workpiece is transported between the processing units only for the purpose of forming the auxiliary circulation oil passage, and the appropriate position of the milling machine or drilling machine is selected. The step of setting the value on the first position can be omitted. Since the bearings, the outer shaft, the propeller boss, and the like are quite heavy , any one of such steps can reduce the manufacturing cost to a considerable extent.

The bearing lubricating structure according to claim 1, the auxiliary循
With respect to forming the ring oil passage in a member outside the bearing,
In particular, it has the following structure.
In other words, the boss of the propeller (one of them) is fitted into the outer periphery of the portion of the outer shaft where the bearing is integrated through a closed (i.e., closed space) gap, and the outer shaft is fitted inside and outside. Holes that penetrate and communicate with the gaps are provided at positions outside the respective end faces of the bearing (positions on the stern side from the rear end face of the bearing and on the bow side from the front end face). An auxiliary circulation oil passage is formed . In order to fit the propeller boss to the outer periphery of the outer shaft through the closed gap, for example, one end surface of the propeller boss is fixed to a flange surface formed on the outer shaft, and an annular member attached to the outer shaft is attached to the boss by the same boss. It can be easily realized if it is fixed close to the other end face. In such a bearing lubrication structure, the above-mentioned auxiliary circulating oil passage enters the above-mentioned gap from the hole passing through the outer shaft inside and outside at a position outside the end face of the bearing far from the return port, and enters the above-mentioned gap in the axial direction. Through the hole passing through the outer shaft in and out of the bearing end face near the return port, and to the end face (end face near the return port).

[0017] In this bearing lubricating structure according to claim 1, if set the outer diameter of that portion of the inner diameter and the outer shaft of the propeller boss to allow a gap as described above, the outer shaft so as to communicate the gap An auxiliary circulation oil passage can be created simply by making a short hole that penetrates inside and outside. In other words, there is no need to form a groove or a hole which is long in the axial direction as an auxiliary circulating oil passage in a milling machine or a drilling machine in any of the bearing, the outer shaft, the propeller boss, the inner shaft and the like, which is particularly advantageous in manufacturing.

In the structure of the first aspect, the mechanical strength around the bearing is easily ensured. The auxiliary circulation oil passage is not provided in the bearing itself, and it is possible to firmly attach the propeller boss to the outer periphery of the outer shaft through a gap without sacrificing strength, and penetrate the outer shaft in and out. This is because the holes need only be small in diameter and small in number.

According to a second aspect of the present invention, there is provided a bearing lubrication structure comprising an auxiliary circulation oil passage.
In the outer member of the bearing.
Unlike the above structure , another cylindrical member is disposed between the bearing and the outer shaft to be integrated with the bearing and the outer shaft, and the auxiliary circulation oil passage is formed through the thickness of the cylindrical member. -Has the following characteristics: Examples of the other cylindrical member here include, for example, a partition cylinder that divides a space between an outer shaft and an inner shaft in a radial direction and forms a lubricating oil passage for a reversal seal.
A part of a so-called pressurized oil introduction cylinder can be arranged.

The cylindrical member integrated between the bearing and the outer shaft is not a member for transmitting power like the outer shaft or the inner shaft, nor does it have a sliding surface that rotates relatively at a high speed like a bearing. Therefore, even if a groove or a hole as an auxiliary circulation oil passage is machined in this, there is almost no disadvantage in strength. In addition, since the member that does not transmit power is generally configured to be light in weight, it does not take much effort to form a groove or a hole in the member. That is, it can be said that the bearing lubrication structure of the second aspect is also advantageous in securing mechanical strength around the bearing and manufacturing the bearing.

According to a third aspect of the present invention, there is provided a bearing lubrication structure comprising an auxiliary circulation oil passage.
In the outer member of the bearing.
-Unlike the structure of 2, it is also characterized in that the above-mentioned auxiliary circulation oil passage is formed through the thickness of the outer shaft. Such a structure also provides a manufacturing advantage when, for example, the lubricating oil passage of the reversal seal is formed within the thickness of the outer shaft. In such a case, it is not necessary to set an outer shaft or the like on a drilling machine or a milling machine for machining only the auxiliary circulation oil passage. Also, it is easier to secure mechanical strength than forming a groove or a hole in the bearing itself.

According to a fourth aspect of the present invention, in addition to the features described above, a forward oil passage is formed inside the inner shaft, an oil supply port is provided on the outer peripheral surface of the inner shaft, and a return oil passage is provided. Is characterized in that a return port is provided on the inner peripheral surface of the outer shaft, and the outer shaft is formed so as to penetrate the outer shaft in and out to communicate with the fixed piping in the hull. Out refueling source in order to smoothly circulate the lubricant oil to return to the same oil supply source (tank) is must be made from the oil passage so that the lubricating oil flows through the constant orientation to the lubricating points and the like, this claim If the outgoing oil passage and the return oil passage are separately provided as in item 4 , the flow in a certain direction can be performed without providing a special partition member (or by providing a minimum partition member). Can be formed. In addition, since the oil passage is formed inside the inner shaft and its oil supply port is provided on the outer peripheral surface of the inner shaft, the hole between the bearing and the inner shaft can be formed without making a hole penetrating the bearing in the radial direction. It is possible to refuel the slip surface at If it is not necessary to make a hole in the bearing in the radial direction, it is needless to say that the strength of the bearing can be easily ensured.

[0023]

1 to 3 show an embodiment of the present invention. FIG. 1 is a longitudinal sectional view showing a stern-side reversing bearing 5 and its lubricating structure in the contra-rotating propeller 1 shown in FIG. 3, and FIG. FIG. 3 is a longitudinal sectional view showing a bearing 6 and a lubricating structure thereof. FIG. 3 is a schematic diagram generally showing the contra-rotating propeller 1 and the like.

As shown in FIG. 3, the front and rear propellers 3.2 of the contra-rotating propeller 1 are attached to a hollow outer shaft 20 and an inner shaft 10 passed through the inside thereof, respectively. Are rotated in opposite directions. The outer shaft 20 is supported by a stern tube bearing 4a, which is a dynamic pressure-type slide bearing, at a portion penetrating the hull 4 in and out (and a portion on the bow side not shown), and a joint 7a is provided at an end on the bow side. It is connected to the hollow drive shaft 7 through the intermediary. Reversing bearings (bearing bushes) 5 and 6 are integrated with each other on the inner side of the outer shaft 20 and on the stern side and the bow side by interference fit. The inner shaft 10 is supported so as to be relatively rotatable. Considering that a considerable load acts on the outer shaft 20 from the propeller 3, the position of the bearing 5 arranged on the stern side is set inside the boss 3a of the propeller 3.

Each of the bearings 5 and 6 is a slide bearing made of cast iron having a bearing surface coated with white metal and having a sliding surface between each inner peripheral surface and the outer peripheral surface of the inner shaft 10. This is a hydrostatic bearing that forms an oil film by externally feeding lubricating oil between surfaces. The inner shaft 10 and the outer shaft 20 rotate at substantially the same speed in opposite directions to each other with respect to the sliding surfaces of the bearings 5 and 6 on which the oil film is formed as described above. In order to prevent the lubricating oil supplied to the slip surface from leaking near the stern side end face of the bearing 5 on the stern side and near the bow side end face of the bearing 6 on the bow side.
Inverting seals 23 and 24 are arranged respectively.

As shown in FIG. 3, the lubricating oil for forming an oil film on the sliding surfaces of the reversing bearings 5 and 6 is sent from an oil supply source 31 mounted on the hull 4 and returned to the circulation path again. Supplied along. The outline of the route is as follows. First, the lubricating oil is sent from the oil supply source 31 and passes through the outgoing oil passage 32, and is supplied to the above-mentioned slip surface, that is, the gap between the bearings 5 and 6 and the inner shaft 10. The lubricating oil overflowing from the slip surface of one bearing 5 is
The lubricating oil flowing through the oil passage 33 between the outer shafts 20 toward the bow side (to the right in the figure) and coming out of the slip surface of the bearing 6 is subjected to the same oil passage 3
5 flows to the stern side (left side in the figure), flows into the return port 37a penetrating the outer shaft 20 in and out, enters the return oil passage 37, and returns to the refueling source 31. In addition, as shown in FIG.
The refueling source 31 includes a tank 31a and a high-pressure refueling pump 31b. In the outgoing oil passage 32, in addition to the fixed oil supply pipe 32a, through holes 32b, 32c, and 32e formed in the inner shaft 10 in the axial and radial directions, respectively, as shown in the drawing, and each bearing. 5.
The desired oil supply ports 32d and 32f are included between the 6 sliding surfaces. The return oil passage 37 includes the return port 37 described above.
a is followed by an annular space 37b, and further connected to a through hole 37c in the hull 4 and a fixed pipe 37d (including an air vent 37e).

A part of the lubricating oil supplied to the slip surface of the bearing 5 from the oil inlet 32d through the through holes 32b and 32c in the inner shaft 10 partially flows on the slip surface to the bow side, and the above-mentioned oil passage 3
3, while the remaining lubricating oil flows on the slip surface to the stern side (far from the return port 37a) and reaches the front surface of the reversal seal 23. Thus, the reversal seal 23
If the lubricating oil that has reached the front surface of the second member does not form a smooth flow to the return port 37a, the pressure may be excessively high, damaging the reversal seal 23 or impairing the performance of the bearing 5. Therefore, an auxiliary circulation oil passage 34 as shown in FIG. 1 is formed from the vicinity of the end on the stern side (near the front surface of the reversing seal 23) to the vicinity of the end on the bow side of the bearing 5, and includes the bearing 5 Of the lubrication structure.

The auxiliary circulation oil passage 34 is not formed in the bearing 5 itself, but is formed outside the outer shaft 20 as shown in FIG. That is, a hole 22a that penetrates the outer shaft 20 inward and outward is formed at a position on the stern side of the rear end face of the bearing 5 and in front of the reversing seal 23, and a similar position is formed on the bow side of the front end face of the bearing 5. And a gap 22b communicating therewith is provided between the outer peripheral surface of the outer shaft 20 and the inner peripheral surface of the boss 3a of the propeller 3. The gap 22b has a thickness of several mm and is formed on the entire outer periphery of the outer shaft 20, and the holes 22a and 22c are preferably provided at several places with a diameter of several tens mm or less and spaced in the circumferential direction. The lubricating oil that has flowed to the stern side of the bearing 5 to the stern side and reached the front surface of the reversing seal 23 is subjected to the above-described hole 22a, gap 22b,
By flowing toward the bow side through the auxiliary circulation oil passage 34 composed of 2c, it joins the oil passage 33 between the outer shaft 20 and the inner shaft 10 to reach the return port 37a (FIG. 3). Since the auxiliary circulation oil passage 34 is not obtained by adding a hole or the like to the bearing 5 itself, the mechanical strength of the bearing 5 is not reduced. In addition, the oil passage 34 is easily formed by providing a diameter difference between the inner diameter of the boss 3a and the outer diameter of the outer shaft 20 and opening a few holes 22a and 22c.
Since the lengths 2a and 22c are short and the positional accuracy does not need to be high, the processing cost is considerably reduced as compared with the case where a hole is formed so as to penetrate the bearing 5 in the axial direction.

In order to provide a gap 22b between the outer shaft 20 and the boss 3a of the propeller 3, the inner diameter of the latter is made larger than the outer diameter of the former.
The boss 3a is attached to the outer shaft 20 with a special structure so that the boss 3a does not become unstable. That is,
A flange 21 is formed on a part of the outer shaft 20 (immediately in front of the place where the bearing 5 is arranged), and a bow-side end face of the boss 3a is joined to a stern-side end face of the flange 21 to form a bolt (not shown). ) And the like were fixed together. Also,
In the vicinity of the end face of the boss 3a on the stern side, as shown in FIG. 1, by attaching a seal holding ring 23a so as to be in close contact with the inner peripheral face of the boss 3a and the end face of the outer shaft 20, the gap 22b is formed outside the lubricating oil. It is a closed space without leakage.

In the contra-rotating propeller 1 shown in FIG. 3, the sliding surface of the reversing bearing 6 on the bow side is also adjusted to the return port 3 described above.
There is lubricating oil flowing to the side far from 7a. That is, of the lubricating oil supplied to the slip surface of the bearing 6 from the through holes 32b and 32e in the inner shaft 10 and the oil supply port 32f, a part of the lubricating oil flows on the slip surface toward the stern side and returns from the oil passage 35 to the return port 37a. However, the remaining lubricating oil flows on the slip surface toward the bow (farther from the return port 37a) and reaches the front surface of the reversal seal 24. In order to prevent the pressure from excessively increasing, protect the reversal seal 24, and allow the bearing 6 to exhibit its original performance, it is necessary to smoothly send the latter lubricating oil to the return port 37a as well as the former lubricating oil. There is. Therefore, an auxiliary circulation oil passage 36 is formed from the vicinity of the end of the bearing 6 on the bow side (near the rearward facing surface of the reversing seal 24) to the stern side, as shown in FIG. Make up the structure.

Auxiliary circulating oil passage 3 for bearing 6 on bow side
6 is formed not on the bearing 6 itself but on a member outside thereof. That is, in this embodiment, the reversal seal 23
In order to form the outward path and the return path for supplying the lubricating oil to the radial direction 24 in the radial direction and to arrange the signal lines of various sensors at fixed positions, as shown in FIG. The oil introduction cylinder 40 is mounted, but the end of the pressure oil introduction cylinder 40 is extended to the outside of the bearing 6 to form a thick portion 40a, which is tightly fitted to the bearing 6 and the outer shaft 20. The auxiliary circulation oil passage 36 is provided inside the thick portion 40a. The auxiliary circulation oil passage 36
Are as shown in FIG. That is, the thick portion 40
a of the forward end face of the bearing 6 on the bow side (reversal seal 24
Hole 40b that is not penetrated from the inner surface to
And a hole 40c penetrating through the thick portion 40a in the axial direction and communicating with the hole 40b. Holes 40d penetrating inside and outside are formed in the pressure oil introducing cylinder 40 at locations other than the thick portion 40b.
40d constitutes a series of auxiliary circulation oil passages 36. It is sufficient that the holes 40b, 40c, and 40d have diameters of several millimeters to several tens of millimeters, and are provided at several locations at intervals in the circumferential direction of the pressure oil introduction cylinder 40. The lubricating oil flowing on the slip surface of the bearing 6 toward the bow and reaching the rearward surface of the reversing seal 24 flows through the auxiliary circulation oil passage 36 toward the stern side, and the oil between the outer shaft 20 and the inner shaft 10. It joins the road 35 and reaches the return port 37a in FIG. This lubricating oil returns to the tank 31a of the oil supply source 31 through the return oil passage 37 from the return port 37a together with the lubricating oil supplied to the bearing 5 on the stern side.

The auxiliary circulating oil passage 36 shown in FIG. 2 does not suffer from disadvantages in mechanical strength because the bearing 6 is not formed by drilling or the like. Drilling of the pressure oil introducing cylinder 40, which is not a power transmission member and does not have a high-speed sliding surface, is particularly meticulous with respect to handling and processing accuracy of a workpiece (in this case, the pressure oil introducing cylinder 40). Processing is easy because no attention is required. In addition, since a hole (not shown) for supplying lubricating oil to the reversing seals 23 and 24 is formed in the pressure oil introducing cylinder 40, the holes 40b and 4 are formed in the holes.
No special preparation is required to open 0c and 40d. In other words, the pressurized oil introducing cylinder 4
When 0 is set, the latter hole (ie, hole 40b.4)
0c and 40d) can also be processed at the same time, and the processing time can be saved to some extent.

On the stern side, the thick portion at the end of the pressure oil introducing cylinder 40 is extended to be fixed between the outer shaft 20 and the bearing 5, and an auxiliary circulation oil passage is formed inside the thick portion. It is also possible to take an embodiment such as making a hole. Therefore, the embodiment as shown in FIG. 2 can be adopted not only for the bow-side bearing 6 but also for the stern-side bearing 5.

FIG. 4 shows another embodiment of the present invention. FIG. 4A is a longitudinal sectional view showing a configuration other than FIG. 1 regarding the stern-side reversing bearing 5 and its lubrication structure in the contra-rotating propeller 1 shown in FIG. 3, and FIG. It is bb sectional drawing in. The same components as those in the embodiments of FIGS. 1 to 3 are denoted by the same reference numerals (portions which are denoted by the same reference numerals and whose description is omitted below do not differ from the configurations of FIGS. 1 to 3).

Of the lubricating oil supplied to the sliding surface of the bearing 5 from the through holes 32b and 32c and the oil supply port 32d in the inner shaft 10, the sliding surface is moved toward the stern side (left side in the figure, far from the return port). In order to smoothly flow the lubricating oil that has flowed and reached the front surface of the reversing seal 23 to the return port 37a (FIG. 3), the lubricating structure of FIG. A path 38 is formed. That is, a position on the stern side of the rear end face of the bearing 5 and in front of the reversal seal 23,
And a non-penetrating hole 22e extending from the inner surface of the outer shaft 20 to a middle thickness portion at a position on the bow side of the front end surface of the bearing 5.
22g, and a hole 22f is formed in the axial direction in the middle of the thickness of the outer shaft 20 to form a hole 22e.
g, and a series of these holes 22e, 22f, 22g
Is an auxiliary circulation oil passage 38. No holes are formed in the bearing 5 itself, which is also made of a copper alloy. Inverted seal 2
The lubricating oil reaching the front of the auxiliary circulation oil passage 3
8 flows toward the bow side and joins the oil passage 33 between the outer shaft 20 and the inner shaft 10 to reach the return port 37a (FIG. 3). To actually form the hole 22f, a method is used in which drilling is performed from the stern side end surface of the outer shaft 20 with a drilling machine and the like, and the opening on the end surface is closed with a plug or the like. Holes 22e / 22f / 22g
May be provided at several places circumferentially spaced with a diameter of about 10 mm, but the boss 3a of the propeller 3
Since the thickness of the outer shaft 20 between the bearing and the bearing 5 is relatively thick,
There is no particular difficulty in drilling such holes, and almost no disadvantage in strength occurs in the outer shaft 20. Note that such an auxiliary circulation oil passage 38 can be formed around the bearing 6 on the bow side.

[0036]

The bearing lubricating structure for a contra-rotating marine propeller according to any one of claims 1 to 3 has an auxiliary circulating oil passage, that is, the lubricating oil supplied to the sliding surface of the reversing bearing, which is farther from the return port. An oil passage for returning the flowed material to the return port side is formed in a member other than the inside of the reversing bearing and is not formed in the bearing itself, so that mechanical strength around the bearing is secured and the bearing is secured. Provides advantages with respect to the manufacture of The point that it is easy to ensure mechanical strength makes it possible to reduce the size of the bearing, and thus also make the outer shaft outside thereof smaller, so that the contra-rotating propeller can be made smaller overall. This also leads to a reduction in the weight of the contra-rotating propeller and a reduction in cost. The advantage in manufacturing is that it is not necessary to reset the bearing to a drilling machine etc. only for the purpose of forming the auxiliary circulation oil passage, but this point also has the effect of reducing the manufacturing cost of the contra-rotating propeller. Lead.

The bearing lubricating structure according to claim 1 is obtained by forming the auxiliary circulation oil path, such as by providing a closed gap between the propeller boss and the outer shaft, bearings and the outer shaft, the propeller boss or Since it is not necessary to form a long groove or hole in any of the inner shaft and the like, it is particularly advantageous in manufacturing.

In the bearing lubricating structure according to the second aspect , another cylindrical member is disposed between the bearing and the outer shaft to form an auxiliary circulation oil passage therein, which also ensures mechanical strength around the bearing. And the manufacture of bearings. When a so-called pressure oil introduction cylinder is used as the cylindrical member, a hole or the like as an auxiliary circulation oil passage is particularly easily formed.

In the bearing lubrication structure of the third aspect , the auxiliary circulation oil passage is formed through the thickness of the outer shaft. For example, when the lubrication oil passage of the reversing seal is formed within the thickness of the outer shaft, etc. Provides manufacturing advantages. Since no grooves or holes are formed in the bearing itself, it is easy to secure mechanical strength.

The bearing lubricating structure according to claim 4 further has a structure in which the outgoing oil passage is formed inside the inner shaft and the return oil passage is formed as the inner and outer through holes of the outer shaft. It is easy to form a flow in a certain direction. Further, since lubrication can be achieved on the sliding surface without making a hole penetrating the bearing in the radial direction, it is easier to secure the strength of the bearing.

[Brief description of the drawings]

FIG. 1 is a view showing an embodiment of the present invention, and is a longitudinal sectional view showing a stern-side reversing bearing 5 and a lubricating structure thereof in a contra-rotating propeller 1 shown in FIG.

FIG. 2 is a longitudinal sectional view showing a reversing bearing 6 on the bow side of the contra-rotating propeller 1 of FIG. 3 and a lubricating structure thereof.

FIG. 3 is a schematic diagram generally showing a contra-rotating propeller 1 and the like.

FIG. 4 shows another embodiment of the present invention. FIG. 4 (a) shows a stern-side reversing bearing 5 of the contra-rotating propeller 1 shown in FIG. FIG. 4B is a longitudinal sectional view showing the configuration, and FIG. 4B is a bb sectional view in FIG.

FIG. 5 (a) is a longitudinal sectional view showing an outboard part of a contra-rotating marine propeller 51 including a conventional bearing lubrication structure,
(B) is a cross-sectional view taken along line bb in (a).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Contra-rotating propeller 2.3 Propeller 3a Boss 5.6 Bearing (reversing bearing) 10 Inner shaft 20 Outer shaft 31 Oil supply source 32 Outgoing oil passage 32d / 32f Oil supply port 34/36/38 Auxiliary circulation oil passage 37 Return Oil passage 37a Return port 40 Pressure oil introduction cylinder (cylindrical member)

Continuation of the front page (56) References JP-A-8-74851 (JP, A) JP-A-6-107285 (JP, A) JP-A-9-48397 (JP, A) JP-A-7-69292 (JP, A) , A) Japanese Utility Model Hei 3-72099 (JP, U) Japanese Utility Model Hei 5-23437 (JP, Y2) (58) Field surveyed (Int. Cl. ⁶ , DB name) B63H 23/36 B63H 5/10

Claims (4)

(57) [Claims] A bearing is integrated inside a cylindrical outer shaft that drives one of the contra-rotating propellers, and an inner shaft that drives the other propeller is passed through the inside of the bearing to form an outer shaft. And a space between the outer and inner shafts, which leads from the oil supply to the oil supply port facing the gap between the bearing and the inner shaft and sends lubricating oil to the gap. A reverse lubrication structure for a marine contra-rotating propeller provided with a return oil passage that returns lubricating oil from a return port facing the oil supply source, and the bearing and the inner shaft exit the oil supply port of the forward oil path. An auxiliary circulation oil passage is formed inside the bearing for sending the lubricating oil flowing through the gap away from the return port to the one end face of the bearing to the other end face side of the bearing. without that it is formed within the outer member, i.e., the propeller Scan is the integral part of the bearing of the outer shaft
While being fitted to the outer circumference via a closed gap,
Holes that penetrate the outer shaft inside and outside and communicate with the above clearances
It is provided at a position outside the end face, and
A bearing lubrication structure for a contra-rotating marine propeller, wherein the auxiliary circulation oil passage is formed by the gap. 2. A propeller of one of contra-rotating propellers.
The bearing is integrated inside the cylindrical outer shaft that drives the
The inner shaft driving the other propeller is threaded inside its bearing
It is arranged so as to be rotatable relative to the outer shaft, and communicates from the oil supply source to the oil supply port facing the gap between the bearing and the inner shaft.
Between the outer oil passage and the inner shaft
Return the lubricating oil to the oil supply through the return port facing the space
Bearing lubrication of marine contra-rotating propeller with return oil passage
A structure, a clearance between the bearing and the inner shaft after leaving the filler opening of the oil passage of the forward
Flows away from the return port at one end of the bearing
To send the lubricating oil that has reached the surface to the other end of the bearing.
The auxiliary circulating oil passage is not formed inside the bearing,
That is, the other cylindrical member is disposed between the bearing and the outer shaft so that the bearing and the
And the above-mentioned auxiliary circulating oil passage is
Bearing lubricating structure of a marine contra-rotating propeller, characterized in that it is formed through the thickness of the wood. 3. A propeller of one of contra-rotating propellers.
The bearing is integrated inside the cylindrical outer shaft that drives the
The inner shaft driving the other propeller is threaded inside its bearing
It is arranged so as to be rotatable relative to the outer shaft, and communicates from the oil supply source to the oil supply port facing the gap between the bearing and the inner shaft.
Between the outer oil passage and the inner shaft
Return the lubricating oil to the oil supply through the return port facing the space
Bearing lubrication of marine contra-rotating propeller with return oil passage
A structure, a clearance between the bearing and the inner shaft after leaving the filler opening of the oil passage of the forward
Flows away from the return port at one end of the bearing
To send the lubricating oil that has reached the surface to the other end of the bearing.
The auxiliary circulating oil passage is not formed inside the bearing,
That is, the auxiliary circulation oil passage is formed through the thickness of the outer shaft.
Bearing lubricating structure of a marine contra-rotating propeller, characterized in that is. 4. The outgoing oil passage is formed inside the inner shaft.
Oil supply port on the outer peripheral surface of the inner shaft, and the return oil passage is
A return port is provided on the inner peripheral surface of the
It is formed so as to communicate with the fixed piping inside
The bearing lubrication structure for a contra-rotating marine propeller according to any one of claims 1 to 3 .