JPH055340Y2 - - 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 through the inner shaft 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 by 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 reversible to each other.

[Means for Solving the Problems] The present invention provides a counter-rotating shaft in which an inner shaft and an outer shaft are driven in reverse to each other via a reversing gear. A seal liner is fitted and fixed, a single seal ring supported on the outer shaft side is brought into contact with the seal liner, and the seal ring is moved away from the atmosphere side back surface toward the atmosphere side on the extending portion of the seal liner. A tapered portion is formed so that the outer diameter gradually decreases according to the amount of time, and an injection means is provided for spraying lubricating oil onto the tapered portion.

[Operation] The lubricating oil sprayed onto the tapered portion of the seal liner by the injection means is efficiently and efficiently sprayed onto the atmosphere-side back surface of the seal ring along the tapered portion due to the centrifugal force generated by the rotation of the inner shaft and the seal liner. It is reliably supplied and suppresses the generation of frictional heat of the single seal ring.

[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, and a uniform outer diameter portion 3 having a required length from the end of the outer shaft 2 is provided on the outer peripheral surface of the cylindrical portion 31.
The tapered portion 32 is formed such that the outer diameter gradually decreases toward the flange portion 30 side through the portion 6.

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 arranged such that the inner edge of the seal ring 33 is folded back toward the outer shaft 2 side and abuts against the outer peripheral surface of the uniform outer diameter portion 36 of the cylindrical portion 31 of the seal liner 29. Along with installing
The folded inner edge of the seal ring 33 is
Atmospheric side A due to the pressure of the lubricating oil r between the 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. Inner peripheral surface 3 of the back-up spring 34
5 is disposed at the boundary between the uniform outer diameter portion 36 and the tapered portion 32 of the cylindrical portion 31 of the seal liner 29 with a desired gap.

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 face the tapered portion 32.

Next, the operation of this embodiment will be explained.

With respect to the seal liner 29 rotating together with the inner shaft 3, the single seal ring 33 rotates in the opposite direction while being in contact with the outer peripheral surface of the uniform outer diameter portion 36 with its back surface supported by the back-up spring 34.
The lubricating oil r press-fitted between the inner and outer shafts 3 and 2 is sealed.

At this time, the seal ring 33 has a uniform outer diameter portion 36
Although heat is generated due to friction with the outer peripheral surface, when the lubricating oil T is sprayed from the opening 39 of the injection pipe 38 toward the tapered part 32 by a lubricating oil injection device (not shown), the lubricating oil T is transferred to the inner shaft 3. and seal liner 2
Due to the centrifugal force generated by the rotation of 9, the seal ring 33 moves on the inclined outer peripheral surface of the tapered portion 32.
Even if the gap between the outer circumferential surface of the seal liner 29 and the backup spring 34 is narrow, the opening 39 of the injection pipe 38 can be closed between the tapered portion 32 and the backup spring 34. The lubricating oil T can be efficiently and reliably supplied to the back surface of the seal ring 33 on the atmosphere side even if it is not placed close to the gap. As a result, the seal ring 33 is lubricated and cooled, heat generation is suppressed, 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 durability 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 durability 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 a tapered part, 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 an inner shaft and an outer shaft are driven in reverse to each other via a reversing gear, a seal liner extending further from the end of the outer shaft is fitted and fixed to the inner shaft, and an outer shaft is attached to the inner shaft. A single seal ring supported on the shaft side is brought into contact with the seal liner, and a tapered part is formed in the extending part of the seal liner so that the outer diameter gradually decreases as the seal ring moves away from the atmosphere side back surface toward the atmosphere side. A counter-rotating shaft sealing device, characterized in that a spraying means for spraying lubricating oil onto the tapered portion is provided.