KR101380658B1 - Propulsion apparatus for ship, and ship having the same - Google Patents

Abstract

A ship propulsion device and a ship equipped with the propulsion device are disclosed. Ship propulsion apparatus according to an embodiment of the present invention includes a rear propeller fixed to the drive shaft, a front propeller rotatably supported on the drive shaft in front of the rear propeller, a reverse rotation device for inverting and transmitting the rotation of the drive shaft to the front propeller, The reverse rotation device is installed by being installed from the outside of the hull in the installation space formed at the rear of the hull, and the outer surface is supported by the inner circumferential surface of the installation space, the drive gear fixed to the drive shaft, the driven gear fixed to the hub of the front repeller, the drive gear It includes one or more inverted gears to reverse the rotation of the driven gear to transmit, and includes a gap adjusting member installed between the driven gear and the front propeller hub to maintain a constant distance between the reverse gear and the driven gear.

Description

[0001] PROPULATION APPARATUS FOR SHIP AND SHIP HAVING THE SAME [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propulsion device for a ship and a ship equipped with the propulsion device, and more particularly, to a propulsion device for a ship in which two propellers rotate in opposite directions to generate propulsive force and a ship equipped with the propulsion device.

The propulsion unit on the ship is a device that generates propulsion force for the operation. The most common one is the use of a single spiral propeller. However, the propulsion system equipped with one propeller has a large energy loss because the rotational energy of the water stream can not be utilized as a propulsion force.

There is a counter rotating propeller (CRP) that can recover lost rotational energy by propulsion. In the double reversing propulsion system, two propellers installed on the same axis rotate propelling each other to generate propulsive force. The rotational energy of the fluid passing through the forward propeller can be recovered by propulsion by rotating the propeller in the reverse direction. Therefore, it is possible to exert a high propulsion performance in comparison with a propulsion device equipped with one propeller.

The double reversing propulsion device has an inner shaft connected to the engine inside the hull, a rear propeller coupled to the inner shaft rear end, a hollow outer shaft provided to rotate on the outer surface of the inner shaft, and a front propeller coupled to the outer shaft rear end. And a reverse rotation device provided inside the hull to transmit the rotation of the inner shaft to the outer shaft for transmission. As the reverse rotation device, a conventional planetary gear device is used.

 However, since the double reversing propulsion device has a hollow outer shaft extending from the reverse rotation device to the rear of the hull, it is very difficult to align the inner shaft and the outer shaft when installing the ship on the ship. In addition, since the external axis is long, the area to be lubricated increases in order to reduce the friction between the internal axis and the external axis. In addition, since the inner shaft and the outer shaft rotate in opposite directions, the shearing of the lubricating film formed between the inner shaft and the outer shaft is generated, so that it is difficult to realize effective lubrication.

The embodiment of the present invention is intended to provide a propulsion device for a ship capable of implementing mutual inversion of two propellers without an outer shaft and a ship equipped with the propulsion device.

According to an aspect of the present invention, a rear propeller fixed to a drive shaft, a front propeller rotatably supported by the drive shaft in front of the rear propeller, and a reverse rotation device for inverting and transmitting the rotation of the drive shaft to the front propeller; The reverse rotation apparatus is installed by being installed from the outside of the hull in the installation space formed at the rear of the hull, the outer surface is supported by the inner peripheral surface of the installation space, the drive gear fixed to the drive shaft, fixed to the hub of the front propeller And at least one inverting gear for inverting and transmitting rotation of the drive gear to the driven gear, and between the driven gear and the front propeller hub to maintain a constant distance between the inverting gear and the driven gear. A marine propulsion device may be provided that includes an installed gap adjusting member.
The reverse rotation device may further include a casing installed at the rear of the hull and supporting the shaft of the reverse gear, and the casing may be installed by sliding into the installation space.

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The propulsion device may further include front and rear thrust bearings respectively installed on the front and rear sides of the front propeller hub to support the thrust load transmitted from the front propeller to the drive shaft.

According to another aspect of the invention, the rear propeller fixed to the drive shaft; A front propeller rotatably supported on the drive shaft in front of the rear propeller; An inverted rotating device having a plurality of gears which enter and install from an outer side of the hull in an installation space formed at the rear of the hull, the outer surface of which is supported by an inner circumferential surface of the installation space, and which inverts the rotation of the drive shaft to the front propeller; And a front thrust bearing and a rear thrust bearing respectively installed at the front and rear of the front propeller hub to support the thrust load transmitted from the front propeller to the drive shaft. The reverse rotation apparatus includes a drive fixed to the drive shaft. A gear, a driven gear fixed to the hub of the front propeller, and one or more inverted gears for inverting and transmitting the rotation of the drive gears, to maintain a constant distance between the inverted gears and the driven gears. A ship propulsion device may be provided that includes a gap adjusting member installed between the front thrust bearing and the front propeller hub.

The front propeller may include a reinforcement member provided at a position at which the front thrust bearing is installed, and the gap adjusting member may be installed between the reinforcement member and the front thrust bearing.
According to another aspect of the invention, the rear propeller fixed to the drive shaft; A front propeller rotatably supported on the drive shaft in front of the rear propeller; A reverse gear including a drive gear fixed to the drive shaft, a driven gear fixed to the hub of the front propeller, and a reverse gear for inverting and transmitting the rotation of the drive gear; An installation space provided at the rear of the hull and opened to the outside of the hull to allow the reverse rotation device to enter from the outside of the hull, and supporting an outer surface of the reverse rotation device when the reverse rotation device is accommodated; And a spacing control member installed between the driven gear and the front propeller hub to maintain a constant distance between the inverted gear and the driven gear.

In the propulsion device according to the embodiment of the present invention, the inversion rotating device can be constituted by a plurality of bevel gears and the volume thereof can be reduced, so that the inversion rotating device can be installed at the rear of the hull.

Further, since the propelling device according to the embodiment of the present invention can directly connect the bevel gear and the front propeller of the reverse rotation device, it is possible to transmit the power to the front propeller without using the outer shaft unlike the prior art, Can be implemented.

Further, since the propulsion device according to the embodiment of the present invention does not use the outer shaft, it is possible to easily perform the operation of installing the drive shaft and aligning the center of the shaft after installation.

Further, since the propulsion device according to the embodiment of the present invention can be installed by inserting the reverse rotation device from the rear of the hull to the installation space provided at the back of the hull, installation work of the propulsion device can be easily performed.

In addition, since the propulsion device according to the embodiment of the present invention does not use outer shafts, it is possible to reduce the area required for lubrication and minimize the problems caused by lubrication.

In addition, the propulsion device according to the embodiment of the present invention to accurately space the gap between the reverse bevel gear and the driven bevel gear by installing a gap adjusting member between the driven bevel gear and the front propeller hub, or between the front thrust bearing and the front propeller hub during the installation process. I can keep it.

1 is a sectional view showing a state in which a propulsion device according to an embodiment of the present invention is applied to a ship.
2 is a cross-sectional view of a propulsion device according to an embodiment of the present invention.
3 is an exploded perspective view of a propulsion device according to an embodiment of the present invention.
4 is a cross-sectional view showing the structure of a support ring of the propulsion device according to the embodiment of the present invention.
5 is a sectional view showing an example of mounting a propeller of a propulsion device according to an embodiment of the present invention.
FIG. 6 illustrates a method of installing the inverted bevel gear and the casing assembly of the propulsion device in the hull rear space according to the embodiment of the present invention.
7 is a side view of the inverting bevel gear and casing assembly of the propulsion device according to an embodiment of the present invention.
8 is a sectional view of the first sealing device of the propulsion device according to the embodiment of the present invention.
9 is an exploded perspective view of the first sealing device of the propulsion device according to the embodiment of the present invention.
10 is a sectional view of the second sealing device of the propulsion device according to the embodiment of the present invention.
11 and 12 are modified examples of the propulsion device according to the present embodiment.

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

As shown in FIG. 1, the propulsion device according to the embodiment of the present invention is provided with a double reversing propulsion system, which is installed at the rear end 3 of the hull 1 and in which propellers 20, Device. Here, the rear portion 3 of the hull 1 refers to a portion projecting rearward from the hull 1 in a streamlined manner to support the drive shaft 10 provided with the two propellers 20 and 30, that is, a stern boss ).

2 and 3, the propulsion device includes a drive shaft 10 extending outward from the inside of the hull 1 through the hull aft 3, and a rear propeller 20 fixed to the rear end of the drive shaft 10. , The front propeller 30 rotatably supported by the drive shaft 10 in front of the rear propeller 20, and a reverse rotation device 70 for inverting and transmitting the rotation of the drive shaft 10 to the front propeller 30. do.

1 and 2, the drive shaft 10 is connected to a drive source (2, a diesel engine, a motor, a turbine, etc.) provided inside the hull 1 and passes through the tail 3 of the hull 1 And extends outside the hull. The driving shaft 10 is rotated by the driving source 2 to rotate the rear propeller 20 fixed to the rear end thereof.

As shown in FIG. 2, the driving shaft 10 is provided with a multi-stage outer surface for sequentially installing a reverse rotation device 70, a front propeller 30, and a rear propeller 20 on the outside thereof. A flange portion 11 having a first step portion 12 is provided at a portion where the reverse rotation device 70 is installed and a flange portion 11 is provided at the rear of the flange portion 11 for mounting the front propeller 30, The second step portion 13 is provided with a smaller outer diameter than the first step portion 12. In order to mount the rear propeller 20, the tapered portion 14 is formed behind the second step portion 13 in such a manner that its outer diameter decreases toward the rear. The flange portion 11 may be integrally formed with the drive shaft 10 or may be separately manufactured and then press-fitted into the outer surface of the drive shaft 10.

The rear propeller 20 includes a hub 21 fixed to the rear portion of the drive shaft 10 and a plurality of blades 22 provided on the outer surface of the hub 21. [ The rear propeller 20 is fixed to the drive shaft 10 by pressing the shaft coupling hole 23 formed at the center of the hub 21 into the outer surface of the tapered portion 14 of the drive shaft 10. Further, the fixing nut 24 is fastened to the rear end of the driving shaft 10 to be more firmly fixed to the driving shaft 10. The shaft coupling hole 23 of the hub 21 may be provided in a shape corresponding to the outer surface of the tapered portion 14 of the drive shaft 10. [ 2, reference numeral 25 denotes a propeller cap mounted on the rear propeller hub 21 so as to cover the rear surface of the rear propeller hub 21 and the rear end of the drive shaft 10. [

The front propeller 30 is rotatably installed on the drive shaft 10 at a position spaced apart from the rear propeller 20 by a predetermined distance forward. More specifically, the front propeller 30 includes a hub 31 rotatably supported on the outer surface of the drive shaft 10 and a plurality of wings 32 provided on the outer surface of the hub 31. Since the front propeller 30 rotates in a direction opposite to that of the rear propeller 20, the blade angle is opposite to the blade angle of the rear propeller 20.

The center of the hub 31 of the front propeller 30 is rotatably supported by the radial bearing 51 and both sides of the hub 31 are rotatably supported by the front thrust bearing 52 and the rear thrust bearing 53 .

The inner race of the front thrust bearing 52 is caught by the jaws of the second step portion 13 of the drive shaft 10 and the outer race is supported by the front bearing support portion 33 of the hub 31. The rear thrust bearing 53 is supported so that the inner ring is not pushed axially by the support ring 60 mounted on the outer surface of the drive shaft 10 and the outer ring is supported by the rear bearing support 34 of the hub 31. The radial bearing 51 suffers the radial load of the front propeller 30 acting in the radial direction of the drive shaft 10 and the front and rear thrust bearings 52 and 53 are supported on the drive shaft 10 in the longitudinal direction So as to be able to cope with the respective thrust loads acting thereon. In particular, the front thrust bearing 52 suffers a thrust load acting on the bow from the forward propeller 30 when the ship is advanced, and the rear thrust bearing 53 suffers from the thrust force acting on the stern from the forward propeller 30, It carries the load.

The hub 31 of the front propeller 30 may be provided with reinforcing members 41 and 42 at the positions where the front and rear bearing supports 33 and 34 are provided. The rigidity of the hub 31 is increased by providing the reinforcing members 41 and 42 at the portions where the front thrust bearing 52 and the rear thrust bearing 53 are installed. The reinforcing members 41 and 42 may be made of a steel material having a higher rigidity than the hub 31. [ The reinforcing member 43 may be provided on the front surface of the hub 21 of the rear propeller 20 in a portion contacting the support ring 60 in the same manner.

4, the support ring 60 includes a first support ring 61 and a second support ring 62, which are divided on both sides to form a semicircular shape, and engagement bolts 63 for fastening them, Lt; / RTI > 5, the front propeller 30 and the rear thruster bearing 53 are installed on the drive shaft 10 and then the rear propeller 20 hub 21 is press-fitted into the drive shaft 10 The supporting ring 60 can be installed between the rear propeller hub 21 and the rear thrust bearing 53 in a combined state.

When the rear propeller 20 is installed on the drive shaft 10 in a press-fitting manner, there arises a coupling error of the rear propeller due to the environment, so that the distance between the rear thrust bearing 53 and the rear propeller hub 21 It is difficult to maintain the accuracy exactly. Therefore, after the rear propeller 20 is assembled first, the distance between the rear thrust bearing 53 and the rear propeller hub 21 is measured, and the support ring 60 is manufactured in accordance with the gap to mount the support ring 60 on the drive shaft 10, And the like. 4, the divided first support ring 61 and the second support ring 62 may be fixed to the outer surface of the drive shaft 10 by fastening the engagement bolts 63 to both sides thereof .

The reverse rotation device 70 is installed at the rear end 3 of the hull 1 adjacent to the hub 31 of the front propeller 30 as shown in Fig. To this end, a hull 3 is provided with an installation space 4 for accommodating the reverse rotation device 70. The installation space 4 can be provided in the form of a cylinder whose center coincides with the center of the drive shaft 10 and is open rearward facing the front propeller hub 31.

2 and 3, the reverse rotation device 70 includes a drive bevel gear 71 fixed to the flange portion 11 of the drive shaft 10 to rotate together with the drive shaft 10, a drive bevel gear A driven bevel gear 72 fixed to the front surface of the hub 31 of the front propeller 30 in such a manner that the driven bevel gear 71 faces the driven bevel gear 71, And an inverted bevel gear 73. And a cylindrical casing 75 provided so as to surround the outside of the inverted bevel gear 73 so as to support the plurality of inverted bevel gear shafts 74.

 The driving bevel gear 71 is fixed to the flange portion 11 by fastening a plurality of fixing bolts 71a in a state where the driving bevel gear 71 is supported by the first step portion 12 of the flange portion 11. [ The driven bevel gear 72 is also fixed to the hub 31 by fastening a plurality of fixing bolts 72a in a state where the rear surface of the driven bevel gear 72 is in contact with the front propeller hub 31. [ The inner diameter portion of the driven bevel gear 72 is spaced apart from the outer surface of the drive shaft 10 in order to prevent friction during rotation. 2 shows the manner in which the driven bevel gear 72 is engaged by fastening bolts 72a but the driven bevel gear 72 is welded to the forward propeller hub 31 or integrated with the forward propeller hub 31 .

The plurality of inverted bevel gears 73 are interposed between the driven bevel gears 71 and the driven bevel gears 72, respectively. A shaft 74 supporting each of the inverted bevel gears 73 is formed in a direction intersecting the drive shaft 10 and can be radially arranged around the drive shaft 10. 2 and 7, the outer end of the inverted bevel gear shaft 74 may be fixed to the inner surface of the casing 75 by bolting or welding. A bearing 73a may be provided between each of the inverted bevel gears 73 and the shaft 74 for supporting the inverted bevel gears 73 for smooth rotation of the inverted bevel gears 73.

In this embodiment, a plurality of the inverted bevel gears 73 are exemplified. However, since the inverted bevel gears 73 may be capable of reversing the rotation of the driven bevel gears 71 and transmitting them to the driven bevel gears 72, There is no need to be plural. In the case of a small ship with a small driving load, it is possible to implement the function even with only one inverted bevel gear.

6 and 7, the inverted bevel gears 73 are inserted into the installation space 4 together with the casing 75 while being mounted on the inner surface of the casing 75 by the shaft 74 As shown in FIG. To this end, a plurality of coupling rails 76 are provided on the outer surface of the casing 75 and protrude from the outer surface of the casing 75 in the axial direction of the driving shaft 10 to guide the installation and limit the rotation of the casing 75 after installation . A plurality of engaging grooves 77 are formed on the inner surface of the mounting space 4 so that the engaging rails 76 can be correspondingly engaged. This is because the inverted bevel gears 73, the shaft 74, and the casing 75 can be assembled together as one assembly to facilitate installation. Here, the casing 75 is coupled to the plurality of coupling rails 76 by the plurality of coupling grooves 77, but the casing 75 may be rotated only after the installation, And may be in the form of being combined by one coupling groove.

The reverse rotation device 70 reverses the rotation of the drive bevel gear 71 and transmits the rotation of the drive bevel gear 71 to the driven bevel gear 72 so that the driven bevel gear 72 and the driven bevel gear 71 rotate, It is possible to rotate in the opposite direction. Therefore, the reciprocal rotation of the front propeller (30) directly connected to the driven bevel gear (72) and the rear propeller (20) directly connected to the drive shaft (10) can be realized.

Also, since the inversion device 70 of the present embodiment realizes the inversion through the plurality of bevel gears 71, 72, and 73, the volume thereof can be reduced as compared with the conventional planetary gear type inversion device. Therefore, it is possible to mount the rear end of the hull 3 without increasing the volume of the rear end of the hull. Further, since the inverting rotating device 70 can be mounted on the rear end 3 of the hull, the driven bevel gear 72 and the front propeller hub 31 can be directly connected.

Particularly, in the present embodiment, the rear surface of the driven bevel gear 72 and the front surface of the front propeller hub 31 can be opposed to each other when the inverting rotating device 70 is installed, and the rotation of the driven bevel gear 72 and the hub 31 It is possible to directly connect the driven bevel gear 72 and the front propeller hub 31 since the centers can be matched. Therefore, it is possible to transmit the power to the front propeller 30 without using the outer shaft unlike the prior art. In addition, since there is no outer shaft, the friction factor of the drive shaft 10 can be reduced more than the conventional one, and the lubricating area can be reduced as compared with the conventional one. In addition, since there is no outer shaft, work for installing the drive shaft 10 and aligning the center of the shaft after installation can be easily performed.

Since the conventional planetary gear type inverting and rotating apparatus includes a sun gear installed on a drive shaft, a planetary gear provided outside the sun gear, and a cylindrical internal gear installed outside the planetary gear, the volume thereof is relatively large. In the planetary gear type reverse rotation device, the internal gear disposed at the outermost periphery must be rotated. Therefore, considering the outer casing, the volume becomes very large. Therefore, it is difficult to install it in the rear of the hull as in the case of the present embodiment. Even if it is installed at the back of the hull, there arises a problem of increasing the size of the rear of the hull. In order to transmit power from the cylindrical internal gear to the front propeller, a hollow shaft corresponding to the conventional outer shaft must be used. As a result, it is difficult to simplify the configuration and reduce the volume as in the present embodiment.

2, the propulsion device of the present embodiment includes a radial bearing (not shown) provided between the drive shaft 10 and the hull 1 adjacent to the inversion rotating device 70 for supporting the drive shaft 10 55). This radial bearing 55 contributes to realizing smooth operation of the inversion rotating device 70 by supporting the drive shaft 10 immediately before the inversion rotating device. That is, the radial bearing 55 prevents the radial vibration or shaking of the drive shaft 10, thereby preventing the bite between the drive bevel gear 71 and the inverted bevel gear 73 and the bite between the inverted bevel gear 73 and the driven bevel gear 72 can be precisely maintained.

As shown in FIG. 2, the propulsion device of this embodiment includes a first sealing device 90 that seals between the rear hull 3 and the front propeller hub 31 to prevent intrusion of seawater (or fresh water) or foreign matter, And a second sealing device 110 for sealing between the front propeller hub 31 and the rear propeller hub 21 for the same purpose.

8, the first sealing device 90 includes a cylindrical first lining 91 provided on the front surface of the front propeller hub 31, a first lining 91 contacting the outer surface of the first lining 91, And a cylindrical first sealing member 92 whose one end is fixed to the rear hull 3.

The first sealing member 92 includes a plurality of packings 93a, 93b and 93c spaced apart from each other on the inner surface facing the first lining 91 and in contact with the outer surface of the first lining 91, , 93b, 93c) for supplying a fluid for sealing. The oil passage 95 of the first sealing member 92 can be connected to the lubricating oil supply passage 96 provided in the hull 1 so that lubricating oil having a predetermined pressure can be supplied. The lubricating oil having a pressure is supplied to the grooves between the respective packings 93a, 93b and 93c so that the respective packings 93a, 93b and 93c are pressed against the first lining 91 to come in close contact with each other, .

9, the first lining 91 includes a first member 91a divided into a semicircular shape on both sides so as to be mountable after the front propeller 30 is installed on the drive shaft 10, (91b). The packing 91d can be interposed in the mutually divided portions 91c of the first and second members 91a and 91b so that sealing can be performed when they are mutually coupled. A first binding portion 91e protruding from one side of the divided portion 91c of the first member 91a and a second binding portion 91b protruding from the other side of the divided portion 91c are provided, 2 fastening portions 91f are provided, and the fixing bolts 91g are fastened to the two fastening portions 91f so that the two sides can be firmly engaged with each other. A plurality of fixing bolts 91i can be fastened to the flange 91h fixed to the front propeller hub 31 to be firmly fixed to the hub 31. [

The first sealing member 92 may also be a method of stacking and fixing a plurality of semicircular rings 92a, 92b and 92c in the longitudinal direction of the drive shaft 10 from the outside of the first lining 91. In this case, the plurality of rings 92a, 92b, 92c can be joined together by bolting or welding.

10, the second sealing device 110 includes a cylindrical second lining 111 provided on the front surface of the rear propeller hub 21 and a second lining 111 contacting the outer surface of the second lining 111. [ 111) outer surface and one end of which is fixed to the rear surface of the front propeller hub (31). The second sealing member 112 also includes a plurality of packings 113a, 113b, and 113c provided on the inner surface of the second sealing member 112 as well as the first sealing member 92 and a flow path 115 for supplying the fluid to the grooves between the packing.

The oil passage 115 of the second sealing member 112 is connected to the lubricating oil supply passage 120 provided at the center of the drive shaft 10. To this end, the drive shaft 10 and the support ring 60 are provided with a first connection passage 121 in the radial direction for connecting the lubricating oil supply passage 120 and the inner space 122 of the second lining 111, A second connection channel 123 connecting the inner space 122 of the second lining 111 and the channel 115 of the second sealing member 112 is formed in the reinforcing member 42 of the rear surface of the propeller hub 31 . Lubricating oil for sealing is supplied from the center of the drive shaft 10 toward the second sealing member 112 so as to press the packings 113a, 113b and 113c to thereby achieve sealing.

The second lining 111 and the second sealing member 112 are each formed in a semicircular shape like the first lining 91 and the first sealing member 92 of the first sealing device 90 so that the rear propeller 20 After the support ring 60 is installed.

11 is a modified example of the propulsion device according to the present embodiment. In the example of FIG. 11, the gap adjusting member 81 is installed between the driven bevel gear 72 and the hub 31 of the front propeller 30. This allows the gap adjusting member 81 to mediate the connection between the driven bevel gear 72 and the front propeller 30 hub 31. The gap adjusting member 81 adjusts the gap between the hub 31 and the driven bevel gear 72 during the installation of the propulsion device to accurately maintain the gap between the inverted bevel gear 73 and the driven bevel gear 72. Can be installed as. The gap adjusting member 81 may be selected to an appropriate thickness or installed in layers in consideration of the installation environment.

12 is another modified example of the propulsion device according to the present embodiment. In the example of FIG. 12, the gap adjusting member 82 is installed between the hub 31 and the front thrust bearing 52 of the front propeller 30. This can be realized by installing the gap adjusting member 82 in the gap that can occur between the front thrust bearing 52 and the reinforcing member 41 of the front propeller hub 31 during the installation of the propulsion device. The gap between the driven bevel gear 72 and the inverted bevel gear 73 is also accurately maintained. That is, if a gap occurs between the front thrust bearing 52 and the reinforcing member 41 of the hub 31 in the state where the gap between the driven bevel gear 72 and the inverted bevel gear 73 is adjusted first during the installation process, By installing the gap adjusting member 82 is to eliminate the gap. The gap adjusting member 82 may also be selected to an appropriate thickness or installed in layers in consideration of the installation environment.

The following describes the operation of the propulsion device according to the present embodiment.

When the drive shaft 10 is rotated by the operation of the internal drive source 2 of the hull 1, the propeller 20 rotates together with the rear propeller 20 in the same direction as the drive shaft 10 directly connected to the rear end of the drive shaft 10 . At the same time, the drive bevel gear 71 of the reverse rotation device 70 also rotates together with the drive shaft 10 since it is fixed to the drive shaft 10. The rotation of the driven bevel gear 71 is reversed by the plurality of inverted bevel gears 73 to be transmitted to the driven bevel gear 72 so that the driven bevel gear 72 rotates in the direction opposite to the drive shaft 10. Therefore, the front propeller 30 directly connected to the driven bevel gear 72 rotates in the direction opposite to the rear propeller 20.

The forward propeller 30 and the rear propeller 20, which rotate in opposite directions, generate propelling water in the same direction because their blade angles are opposite to each other. In other words, when the ship moves forward, the propulsion water is generated backward, and when the ship is backward, the propulsion water is generated forward while rotating in the reverse direction. In addition, the propulsion performance of the propulsion water generated when advancing is improved because propulsion power of the fluid through the forward propeller 30 is recovered by the propulsion force of the propeller 20 while being reversed. The same goes for backward.

On the other hand, since the forward propeller 30 generates propelling water rearward when it is advanced, it receives a reaction force corresponding thereto. This force is transmitted to the drive shaft 10 through the front thrust bearing 52 and acts as propulsive force. The rear propeller 20 is also subjected to a reaction force because it generates propelling water rearward when it is advanced. This force is also transmitted to the direct drive shaft 10 and acts as propulsion force.

The propulsive force of the forward propeller 30 is transmitted to the drive shaft 10 through the rear thrust bearing 53 and the propulsive force of the rear propeller 20 is also transmitted to the drive shaft 10 directly connected to the ship. As a result, the propulsion system of the present embodiment transmits the driving force generated by the operation of the front propeller 30 and the rear propeller 20 to the hull 1 through the drive shaft 10 when the ship moves forward and backward.

1: hull, 2: driving source,
3: rear of hull, 4: installation space,
10: drive shaft, 20: rear propeller,
30: front propeller, 41, 42: reinforcing member,
51,55: Radial bearing, 52: Front thrust bearing,
53: rear thrust bearing, 60: support ring,
70: reverse rotation device, 71: driven bevel gear,
72: driven bevel gear, 73: inverted bevel gear,
75: casing, 81, 82: gap adjusting member,
90: first sealing device, 110: second sealing device.

Claims (7)

A rear propeller fixed to a drive shaft, a front propeller rotatably supported by the drive shaft in front of the rear propeller, and a reverse rotation device for inverting and transmitting rotation of the drive shaft to the front propeller,
The reverse rotation device is installed by entering from the outside of the hull into the installation space formed on the rear of the hull, the outer surface is supported by the inner peripheral surface of the installation space, the drive gear fixed to the drive shaft, the driven fixed to the hub of the front propeller A gear and one or more inverting gears for inverting and transmitting rotation of the drive gears;
And a spacing control member disposed between the driven gear and the front propeller hub to maintain a constant distance between the inverted gear and the driven gear. The method of claim 1,
The reverse rotation device further includes a casing installed at the rear of the hull to support the shaft of the reverse gear,
The casing is a marine propulsion unit is installed by entering the installation space in a sliding manner. The method of claim 1,
And a front and rear thrust bearings respectively installed on the front and rear sides of the front propeller hub to support the thrust load transmitted from the front propeller to the drive shaft. A rear propeller fixed to the drive shaft;
A front propeller rotatably supported on the drive shaft in front of the rear propeller;
An inverted rotating device having a plurality of gears which enter and install from an outer side of the hull in an installation space formed at the rear of the hull, the outer surface of which is supported by an inner circumferential surface of the installation space, and which inverts the rotation of the drive shaft to the front propeller; And
And a front thrust bearing and a rear thrust bearing respectively installed at the front and rear of the front propeller hub to support the thrust load transmitted from the front propeller to the drive shaft.
The reverse rotation device includes a drive gear fixed to the drive shaft, a driven gear fixed to the hub of the front propeller, one or more inverted gears for inverting and transmitting the rotation of the drive gear,
And a spacing control member provided between the front thrust bearing and the front propeller hub to maintain a constant distance between the inverted gear and the driven gear. The method of claim 4, wherein
Wherein the reverse rotation device includes a drive gear fixed to the drive shaft, a driven gear fixed to a hub of the forward propeller, and at least one reverse gear that inverts the rotation of the drive gear to the driven gear. 5. The method of claim 4,
The front propeller includes a reinforcing member provided at a position where the front thrust bearing is installed,
The gap adjusting member is a propulsion device for a ship, characterized in that installed between the reinforcing member and the front thrust bearing. A rear propeller fixed to the drive shaft;
A front propeller rotatably supported on the drive shaft in front of the rear propeller;
A reverse gear including a drive gear fixed to the drive shaft, a driven gear fixed to the hub of the front propeller, and a reverse gear for inverting and transmitting the rotation of the drive gear;
An installation space provided at the rear of the hull and opened to the outside of the hull to allow the reverse rotation device to enter from the outside of the hull, and supporting an outer surface of the reverse rotation device when the reverse rotation device is accommodated; And
And a gap adjusting member installed between the driven gear and the front propeller hub to maintain a constant distance between the inverted gear and the driven gear.

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