JPH055341Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a two-way sealing system for sealing the lubricating oil sealed between the inner and outer shafts of counter-rotating shafts that are reversed to each other and used in marine applications. This invention relates to a counter-rotating shaft sealing device.

[Prior Art] In recent years, research has been conducted into the use of counter-rotating shafts in the propulsion shaft systems of large ships in order to increase propulsion efficiency and save energy. The propulsion shaft system will be explained using Fig. 2.

The counter-rotating shaft 1 is inserted into a hollow outer shaft 2, and the outer shaft 2 is
The inner shaft 3 is inserted concentrically with the inner shaft 3 and is configured to be reversible with respect to the other. The rotational driving force of the main engine 4 is directly transmitted to the inner shaft 3 and drives the stern propeller 5. The rotational driving force of the main engine 4 is transmitted from the sun gear 6 provided on the inner shaft 3 to the outer shaft 2 via the planetary gear 8, which is supported by the gear casing 7 and rotates in a fixed position, and the internal gear 9. and drives the bow propeller 10 in reverse. That is, the planetary gear mechanism 11 constitutes a reversing gear.

The weight of the outer shaft 2 is supported by a stern tube bearing 12, and sealing devices 1 are provided at both ends of the bow and stern sides.
Lubricating oil R sealed between 3 and 14, stern tube 15
Lubricated against. On the other hand, the weight of the inner shaft 3 is determined by the inversion bearings 16 and 17 at both ends of the bow and stern sides.
and sealing devices 18 at both ends thereof.
The inner and outer shafts 3 and 2, which are opposite to each other, are lubricated with lubricating oil r sealed between the shafts 19 and 19. Here, these lubricating oils R and r are usually 0.2 to 0.3 higher than the seawater pressure.
The pressure is maintained at a high pressure of approximately Kg/cm ² , and the sealing device for sealing the lubricating oils R and r, particularly the sealing device 13 on the bow side, employs the following lip seal structure.

FIG. 3 is a side sectional view of a bow-side sealing device 13 having a conventional lip seal structure, which is provided between a stern tube 15 that is not rotated and an outer shaft 2 that is rotationally driven. A ring-shaped lip seal 21 attached to an annular seal casing 20 on the end face of the stern tube 15 is in contact with a ring-shaped seal liner 23 attached to the outer shaft 2 via a clamp ring 22, and is sealed by lubricating oil R pressure. It is pressed onto the liner 23 to seal the lubricating oil R.
Since this lip seal 21 generates heat due to friction with the seal liner 23 that rotates together with the outer shaft 2, another lip seal 24 is provided on the back side of this lip seal 21.
A lubricating oil chamber 25 is formed between the seals 24 and 24 , and lubricating oil S is separately supplied to this lubricating oil chamber 25 from a tank 26 to cool the seal 21 .

As for the pressure resistance of both seals 21 and 24, the seal 21 whose both sides are filled with lubricating oils R and S has good lubrication and cooling properties, and can withstand a pressure difference of 2 kg/cm ² . Seal 2 whose other side is exposed to the atmosphere side A
No. 4 has a dry sliding portion with the liner 23 and a high coefficient of friction, so it can withstand only a differential pressure of 0.5 kg/cm ² . Regarding the added lip seal 24, the height of the tank 26 is set so that a pressure of about 0.2 kg/cm ² is applied.
Therefore, it is not pressed strongly against the seal liner 23 and generates less heat, so that the necessary durability is ensured. Furthermore, the lubricating oil S in the lubricating oil chamber 25 is
Since it is heated by the frictional heat of the seals 21 and 24 and the stirring heat, it is circulated between the tank 26 and the tank 26 and the seal 24 are cooled with cold air from the ventilation duct.

[Problems to be Solved by the Invention] Incidentally, in the seal device 13 described above, the lubricating oil chamber 25 can be easily supplied from the seal casing 20 that is not rotated on the stern tube 15 side.

On the other hand, when such a sealing device 13 is adopted between the inner and outer shafts 3 and 2 which are opposite to each other, both the seal casing 20 and the seal liner 23 are rotated, so that the water from the tank 26 is reduced. There was a problem that the refueling structure became complicated.

In view of these circumstances, the present invention aims to provide a counter-rotating shaft sealing device that has a simple structure and can maintain good sealing performance between the inner and outer shafts that are mutually reversible.

[Means for Solving the Problems] The present invention provides a counter-rotating shaft in which the inner shaft and the outer shaft are driven to reverse each other via a reversing gear. a ring-shaped seal casing is provided concentrically on the end surface of the outer shaft, a single seal ring is attached to the seal casing so that the seal ring contacts the outer circumferential surface of the seal liner; A back-up spring that supports the back surface of the seal ring on the atmosphere side is installed so that the inner circumferential surface of the back-up spring and the outer circumferential surface of the seal liner are spaced apart as required, and the back-up spring is attached to the back-up spring from the inner circumferential surface. The oil drain hole is provided with an oil drain hole passing through the side end face on the side of the seal ring, and is provided with an injection means for spraying lubricating oil into the gap between the backup spring and the seal liner.

[Operation] The lubricating oil sprayed into the gap between the seal liner and the back-up spring by the injection means is sequentially discharged from the oil drain hole to the outside of the gap due to the centrifugal force generated by the rotation of the seal liner and back-up spring. As a result, the inside of the gap becomes negative pressure, and new lubricating oil always flows into the gap, and the lubricating oil is efficiently and reliably supplied to the back surface of the seal ring on the atmosphere side. suppresses the generation of frictional heat.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

In FIG. 1, the same reference numerals as in FIG. 2 indicate the same parts.

As shown in FIG. 1, a seal liner 29 extending from the end of the outer shaft 2 toward the sun gear 6 is fitted and fixed to the inner shaft 3 in the inner space 40 of the gear casing 7 by means of a clamp ring 28. The seal liner 2
9 is a cylindrical portion 31 extending a required length from the end of the outer shaft 2;
and a flange portion 30 that comes into contact with the end surface of the clamp ring 28.

On the other hand, a ring-shaped seal casing 27 is attached to the end surface of the outer shaft 2.
First, a single ring-shaped seal ring 33 is attached so that the inner edge of the seal ring 33 is folded back toward the outer shaft 2 side and comes into contact with the outer peripheral surface of the cylindrical portion 31 of the seal liner 29. The folded inner edge is filled with lubricating oil r between the inner and outer shafts 3 and 2.
A back-up spring 34 is attached to the back surface of the seal ring 33 to prevent it from being reversed to the atmosphere side A due to the pressure of the seal ring 33. The inner circumferential surface 35 of the back-up spring 34 is disposed with a desired gap from the outer circumferential surface of the cylindrical portion 31 of the seal liner 29.
is provided with several oil drain holes 32 penetrating from the inner circumferential surface 35 to the side end surface 36 on the side opposite to the seal ring 33.

Furthermore, one end of the rotating shaft 37 of the planetary gear 8 fixed in the fixed position of the gear casing 7, located above the inner shaft 3, was connected to a lubricating oil injection device (not shown) such as a pump. The injection pipe 38 is passed through, and the other end of the injection pipe 38 is inserted into the injection pipe 38.
The other end opening 39 is bent so as to approach the gap between the cylindrical portion 31 and the backup spring 34.

Next, the operation of this embodiment will be explained.

While the seal liner 29 rotates together with the inner shaft 3, the single seal ring 33 rotates in the opposite direction while contacting the outer peripheral surface of the seal liner 29 with its back side supported by the back-up spring 34. The lubricating oil r press-fitted between the outer shafts 3 and 2 is sealed.

At this time, the seal ring 33 is attached to the seal liner 2.
Although heat is generated due to friction with the outer peripheral surface of the injection pipe 38, the opening 39 of the injection pipe 38 is
When lubricating oil T is sprayed into the gap between the cylindrical portion 31 of the seal liner 29 and the backup spring 34, the lubricating oil T is supplied to the back surface of the seal ring 33 on the atmosphere side, and the seal ring 33 is lubricated and cooled. This will reduce fever. Moreover, the lubricating oil T supplied to the atmosphere-side back surface of the seal ring 33 is discharged from the oil drain hole 32 to the side end surface 36 of the backup spring 34 due to the centrifugal force generated by the rotation of the seal liner 29 and the backup spring 34. Therefore, the inside of the gap between the cylindrical part 31 of the seal liner 29 and the backup spring 34 becomes negative pressure, and the new lubricating oil T sprayed from the injection pipe 38 always flows into the atmosphere-side back surface of the seal ring 33, making it more effective. It becomes possible to lubricate and cool the seal ring 33. In this way, the durability of the seal ring 33 is increased, and the lubricating oil r press-fitted between the inner and outer shafts 3 and 2 can be effectively sealed.

Therefore, the pressure resistance required for the single seal ring 33 can be easily ensured without creating a lubricating oil chamber by adding a seal ring or providing a lubricating oil supply system to the lubricating oil chamber.

It should be noted that the present invention is not limited to the embodiments described above, and it goes without saying that various changes may be made without departing from the gist of the present invention.

[Effects of the invention] As described above, according to the invention, lubrication and cooling of the seal ring can be ensured regardless of the rotation of parts around the seal ring, and the necessary pressure resistance can be achieved with a simple structure and a single seal ring. In order to demonstrate its performance,
An excellent effect can be achieved in that the sealing performance between the outer shafts can be maintained well.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view showing an embodiment of the present invention, Fig. 2 is a side sectional view showing a propulsion shaft system equipped with a contra-rotating shaft, and Fig. 3 is an enlarged side sectional view of main parts showing a conventional example. It is. 1 is a counter-rotating shaft, 2 is an outer shaft, 3 is an inner shaft, 11 is a planetary gear mechanism, 27 is a seal casing, 28 is a clamp ring, 29 is a seal liner, 32 is an oil drain hole, 33 is a seal ring, 34 38 is a backup spring, 38 is an injection pipe, and r and T are lubricating oils.

Claims (1)

[Scope of utility model registration request] In a counter-rotating shaft in which the inner shaft and the outer shaft are driven in reverse rotation with each other via a reversing gear, a seal liner that extends further from the outer shaft end is fitted and fixed to the inner shaft, and a ring is attached to the outer shaft end surface. A single seal ring is attached to the seal casing so that the seal ring comes into contact with the outer peripheral surface of the seal liner, and a back-up spring that supports the back surface of the seal ring on the atmosphere side is attached to the seal casing. Install so that the inner circumferential surface of the back-up spring and the outer circumferential surface of the seal liner are arranged with a required gap,
The back-up spring is provided with an oil drain hole that penetrates from the inner peripheral surface toward the side end surface on the side opposite to the seal ring, and an injection means is provided for spraying lubricating oil into the gap between the back-up spring and the seal liner. Features a contra-rotating shaft seal device.