JPH038319B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a watertight stern tube device that supports a propulsion shaft of a ship in a watertight manner.

Conventionally known watertight devices of this type utilize the elasticity of the diaphragm to apply compressive force and sealing pressure to the seal ring.

Conventional devices that use diaphragms to watertight the rotating shaft in the stern tube have weak thrust to press the gland packing, so there was a desire to develop a stern tube watertight device with strong thrust as an alternative. .

Therefore, in the present invention, a gland packing and a pressing ring are fitted into the stern tube through which the rotating shaft is inserted, the support ring of the pressing ring is fixed to the outer end of the stern tube, and the rotating shaft protruding from the stern tube is fitted with a gland packing and a pressing ring. A pressing cylinder having a flange with an inclined inner circumferential surface at the rear end and a through hole provided on the outer periphery is slidably fitted, and the front end of this pressing cylinder is fitted into the support ring. A support screw fixed to the support ring in parallel with the rotation axis is inserted into the through hole of the flange, and the pressing cylinder is placed between the adjustment nut screwed onto the support screw and the flange, so that the pressing cylinder is always facing rearward. While equipped with a biasing ammunition, behind the pressing cylinder,
A second support ring is fitted onto the rotating shaft, and an O-ring is interposed between the inclined outer circumferential surface provided at the front end of this support ring and the inclined inner circumferential surface of the press cylinder. The support ring is inserted through the seal ring provided on the rear end surface.
The present invention provides a stern tube watertight device configured to be supported by a rotating ring that is fixed to a rotating shaft and rotates integrally therewith.

In the present invention configured as described above, the seal ring is supported while being in contact with the inclined inner circumferential surface of the pressing cylinder side that is slidably provided on the rotating shaft and the rotating ring fixed on the rotating shaft. Both the above-mentioned inclinations are caused by the back-and-forth sliding of the pressing cylinder to vibrate the rotating shaft while maintaining watertightness by the inclined outer circumferential surface provided on the second support ring side and the O-ring held between both the inclined surfaces. It elastically absorbs minute changes in the depth of engagement between the surfaces.
Further, by pressing the two inclined surfaces together through the O-ring, a stronger thrust can be obtained than in the conventional device using a diaphragm.

Further, in the present invention, a nut for emergency operation is provided at the tip of the support screw that is inserted through the through hole of the flange so as to maintain the sliding movement of the pressing cylinder. By advancing the position of the nut if the nut is damaged,
This is extremely useful in directly pressing the front end of the pressing cylinder against the pressing ring of the gland packing and urgently avoiding a drop in watertightness of the device of the present invention.

Embodiments of the present invention will be described below with reference to the drawings.

In the figure, 1 is an open stern tube with a flange-shaped rear end. 2 is a gland packing fitted to the rotating shaft 3 in the stern tube. Reference numeral 4 denotes a support ring screwed to the rear end of the stern tube 1 to support the pressing ring 5 that presses the gland packing 2 within the stern tube.
Reference numeral 6 denotes a press cylinder whose front end 7 is fitted into a support ring and slidably fitted onto the rotating shaft 3. Reference numeral 8 denotes an inclined inner circumferential surface provided at the rear end of the press cylinder 6. Reference numeral 9 denotes a flange formed on the outer periphery of the pressing cylinder 6 with through holes 10 arranged in the circumferential direction.
Reference numeral 11 denotes a support screw which is implanted in the support ring 4 and serves as a rotation stopper and sliding guide for the pressing cylinder 6 which is inserted through the through hole 10. Reference numeral 13 denotes a bullet which is interposed between the adjustment nut 12 provided on the support screw 11 and the flange 9, and which constantly urges the pressing cylinder 6 toward the rear. Reference numeral 14 denotes a rotating ring which is fixed on a rotating shaft behind the pressing cylinder 6 and rotates integrally therewith. 16 is a seal ring 1 provided on the rear end surface.
5 is supported by the rotating ring 14, and presses the inclined outer circumferential surface 17 formed at the front end against the inclined inner circumferential surface 8 of the pressing cylinder 6 via the O-ring 18 provided therebetween. Reference numeral 19 denotes an emergency operation nut provided at the tip of the support screw 11 that is inserted through the through hole 10.

This watertight device configured as described above has the following characteristics:
3, the pressing cylinder 6 and the second support ring 16
If the rotating ring 14 is fixed on the rotating shaft 3 while generating sufficient pressing thrust between the two, the inclined inner peripheral surface 18 on the pressing cylinder 6 side and the inclined outer peripheral surface 17 on the second support ring 17 side A seal ring 15 is provided between the second support ring 16 and the rotating ring 14.
As a result, the rotating shaft 3 rotates while maintaining watertightness firmly and elastically.

The device of the present invention configured as described above and operated as described above is provided on a rotating shaft so as to be elastically slidable by a support screw and an elastic device without using a diaphragm. fitting the inclined surfaces of the pressing cylinder and the second support ring supported by the rotating ring fixed on the rotating shaft via the seal ring;
With the O-ring held between them, watertightness of the rotating shaft outside the stern tube can be maintained. Therefore, vibrations of the rotating shaft can be absorbed into the bearing portion without impairing watertightness, and center runout can also be eliminated.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a stern tube watertight device to which the present invention is applied. FIG. 2 is its right side view. 1: Stern tube, 2: Gland packing, 3: Rotating shaft, 4: Support ring, 5: Press ring, 6: Press tube,
7: Tip of the pressing cylinder, 8: Slanted inner peripheral surface provided at the rear end of the pressing cylinder, 9: Flange, 10: Through hole, 1
1: Support screw, 12: Adjustment nut, 13: Bullet machine,
14: rotating ring, 15: seal ring, 16: second support ring, 17: inclined surface of second support ring, 18:
O-ring, 19: Nut for emergency operation.

Claims (1)

[Scope of Claims] 1. A gland packing and a pressing ring are fitted into a stern tube through which a rotating shaft is inserted, and the support ring of the pressing ring is fixed to the outer end of the stern tube, and a rotating shaft protruding from the stern tube is fitted with a gland packing and a pressing ring. A pressing cylinder having a flange with an inclined inner peripheral surface at the rear end and a through hole on the outer periphery is slidably fitted onto the shaft, and the front end of this pressing cylinder is fitted into the support ring. A support screw fixed to the support ring parallel to the rotation axis is inserted into the through hole, and the pressing cylinder is always directed rearward between the adjustment nut screwed into the support screw and the flange. On the other hand, a second support ring is fitted to the rotating shaft at the rear of the pressing cylinder, and the inclined outer peripheral surface provided at the front end of the supporting ring and the inclined inner surface of the pressing cylinder are provided. An O-ring is interposed between the second support ring and the peripheral surface, and the second support ring is supported by a rotating ring that is fixed to the rotating shaft and rotates integrally with the rotating shaft via a seal ring provided on the rear end surface. A stern tube watertight device characterized by comprising: 2. The stern tube watertight device according to claim 1, wherein a nut for emergency operation is provided at the tip of the support screw that is inserted through the through hole of the flange.