JPH10274341A - Bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the leak of the fog-like lubricating oil, which is filled in a bearing box, outside through a clearance of a seal part by providing an inclined wing part to be rotated with a rotary shaft in a seal part of a part, in which the rotary shaft passes through a bearing box, and generating an air flow flowing from outside to inside. SOLUTION: In a seal part 4 of a bearing box 3, an inclined wing plate 9 provided with slots having inclination against the axial direction is provided in the peripheral part of a partitioning plate 2 provided in the periphery of a rotor shaft 1 surrounded by a shielding plate 10. The inclined wing plate 9 provided in the periphery of the partitioning plate 2 generates the work as a fan with rotation of the rotary shaft 1 so as to generate an air flow passing through a clearance between the shielding plate 10, which is assembled in the seal part 4, and the rotor shaft 1. With this structure, leak of the fog-like lubricating oil filled in the bearing box 3 is prevented, and the lubricating oil is forcibly extruded to other oil discharge pipe and exhaust pipe, and the leak of lubricating oil from the seal part 4 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a bearing applied to a rotor shaft of a steam turbine and the like.

[0002]

2. Description of the Related Art FIG. 2 is an explanatory view of a conventional bearing used for a rotor shaft of a steam turbine or the like. In the figure,
The conventional bearing used for the rotor shaft 01 of a steam turbine and the like is provided with a seal portion 04 at a portion where the rotor shaft 01 penetrates from the inside of the bearing housing 03 to the outside. The fitted partition plate 02 and the shielding plate 010 mounted on the bearing box 03 are alternately combined to form an oil-cut plate sealing structure, and lubricating oil and mist leak from the inside of the bearing box 03 to the outside. Is prevented.

[0003] In the bearing housing 03, lubricating oil is supplied to the bearing material 08, and a part of the lubricating oil travels on the rotor shaft 01 and enters the seal portion 04 from the gap with the shielding plate 010. It is blocked by the partition plate 02 and the shield plate 010 provided in the seal portion 04, collected in the drain hole 05 provided below the seal portion 04, and returned into the bearing box 03.

[0004]

In the conventional bearing as described above, when the rotor shaft 01 of the steam turbine rotates at high speed, the dynamic pressure in the bearing housing 03 increases in accordance with the rotation of the rotor shaft 01, The internal pressure of the bearing housing 03 increases.
Further, when the rotor shaft 01 rotates, the lubricating oil is scattered in the bearing box 03 to be in a spray (mist) state, and the bearing box 03 is filled. As a result, the lubricating oil in the spray state inside the bearing box 03 is discharged to the outside of the bearing box 03 through the oil drain pipe 06 and the exhaust pipe 07, but a part of the oil is discharged from the gap of the seal portion 04 to the outside of the bearing box 03. There is a problem such as leakage to

[0005]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problems. The bearing housing and the rotary shaft are connected via a seal member to a portion through which the rotary shaft passes through the bearing housing. In a bearing provided with a seal portion that slides with each other, a swash plate is provided at the seal portion so that the bearing rotates with the rotating shaft to generate an airflow from the outside to the inside of the bearing box. As described above, in the present bearing, the swash plate that rotates together with the rotation shaft is provided at the seal portion where the rotating shaft passes through the bearing box, and the rotating swash blade plate flows from the outside to the inside of the bearing box. An airflow is generated, and the airflow flowing from the outside to the inside of the bearing box causes the lubricating oil filled in the bearing box to be pushed from the outside to the inside of the bearing box.

[0006]

FIG. 1 is an explanatory view of a bearing according to an embodiment of the present invention. In the drawing, the bearing according to the present embodiment is used for a rotor shaft of a steam turbine or the like. In the drawing, reference numeral 1 denotes a rotor shaft, 2 denotes a partition plate, 3 denotes a bearing box, 4 denotes a seal portion, and 5 denotes a drain. Hole, 9 is a swash plate, 10
Is a shielding plate.

[0007] Similar to the conventional bearing, this bearing is provided with a seal portion 4 at a portion where the rotor shaft 1 penetrates from the inside of the bearing housing 3 to the outside, and the seal portion 4 is fitted to the rotor shaft 1. The divided partition plate 2 and the shielding plate 10 mounted on the bearing box 3 are alternately combined to form an oil-cut plate sealing structure, and the leakage of lubricating oil and mist from inside the bearing box 3 to the outside is prevented. Preventing. In the bearing housing 3, lubricating oil is supplied to a bearing material (not shown), and a part of the lubricating oil travels on the rotor shaft 1 and enters the sealing portion 4 through a gap with the shielding plate 10. It is shut off by the partition plate 2 and the shielding plate 10 provided in the inside 4, collected in the drain hole 5 provided below the seal portion 4, and returned into the bearing housing 3.

The bearing housing 3 is provided with an oil drain pipe and an exhaust pipe (not shown). A shield plate 10 is provided on the seal part 4 so as to surround the partition plate 2, and a shield plate 10 in contact with the partition plate 2 is provided outside the shield plate 10 so as to be in contact with the rotor shaft 1. The mounting portion of the shielding plate 10 in the seal portion 4 has a protruding structure, and has a drain hole 5 connected to the inside of the bearing housing 3 at a lower portion thereof. Rotor shaft 1
When is rotated, the supplied lubricating oil is scattered in the bearing housing 3 to be in a spray state.

In the present bearing, as shown in FIG.
The partition plate 2 protruding from the rotor shaft 1 is grooved to form a swash plate 9, and is provided on the circumference of the partition plate 2 at an equal pitch. The plurality of shielding plates 10 fixed to the bearing housing 3 and the rotor shaft 1 and the partition plate 2 are attached and combined so as to secure a predetermined clearance.
The angle of the swash plate 9 provided in the partition plate 2 is
In order to generate an airflow from the outside to the inside, the rotation direction of the rotor shaft 1 is set to a range of 0 <θ <90 °,
Is determined according to the number of rotations. In addition, the inclined blade plate 9 may be directly attached to the rotor shaft 1, the number thereof may be changed as needed, and it is sufficient if the airflow is generated from the outside to the inside of the bearing housing 3. .

As described above, in the present bearing, the partition plate 2 provided on the outer periphery of the rotor shaft 1 and surrounded by the shield plate 4 in the seal portion 4 of the bearing box 3 surrounding the bearing material supplied with the lubricating oil is provided with the rotor shaft 1. The partition plate 2 is formed with a plurality of inclined blades 9 having an uneven shape on the outer periphery of the partition plate 2. The rotor shaft 1 of the steam turbine always rotates at a high speed in the same direction, so that the swash plate 9 incorporated in the seal portion 4 of the bearing housing 3 also rotates at a high speed. Generates airflow in the axial direction. The bevel plate 9 having the oblique angle θ provided on the outer periphery of the partition plate 2 generates the action of a fan when the rotor shaft 1 rotates, and the shield plate 10 and the rotor shaft which are incorporated in the seal portion 4 of the bearing box 3. 1 to generate a flow of air that passes through the clearance. When the rotor shaft 1 rotates at high speed because the partition plate 2 provided on the rotor shaft 1 has a large number of swash blades 9, the skew blade plate 9 causes air in a narrow space between the oil-slicing plate and the rotor shaft 1. To generate an airflow that flows in the axial direction from the outside to the inside of the bearing housing 3 in a small space. The rotation direction of the rotor shaft 1 is always a fixed direction,
By forming a groove so that an airflow flows from the outside of the bearing housing 3 to the inside of the bearing housing 3 at a certain oblique angle in the rotation direction, an airflow passing in the seal portion 4 in a certain direction is secured. As a result, the sprayed lubricating oil filled in the bearing housing 3 is prevented from leaking out of the seal portion 4 to the outside, and is forcibly pushed out to other oil drain pipes and exhaust pipes to be leaked from the seal portion 4. Is prevented. Note that the inclined blade plate 9 may be directly attached to the rotor shaft 1, and the same operation and effect can be obtained by rotating.

In a conventional bearing, when the rotor shaft of the steam turbine rotates at a high speed, the dynamic pressure increases in the bearing housing according to the rotation of the rotor shaft, and the internal pressure of the bearing housing increases. In addition, the rotation of the rotor shaft causes the lubricating oil to be scattered in the bearing box and to be in a spray (mist) state, thereby filling the bearing box. As a result, the sprayed lubricating oil in the bearing housing is discharged to the outside of the bearing housing through the oil drain pipe and exhaust pipe, but a part of the oil leaks out of the bearing housing through the gap in the seal. There is. On the other hand, in the present bearing, the outer periphery of the partition plate 2 on the rotor shaft 1 is grooved with a gradient in the axial direction in order to prevent the sprayed lubricating oil inside the bearing housing 3 from leaking outside. The inclined blade plate 9 is formed, and the inclined blade plate 9 generates an airflow flowing from the outside to the inside of the bearing box 3 so that the lubricating oil does not leak to the outside of the bearing box 3. By pushing the air from the inside toward the inside, it is possible to prevent the leakage of the spray-like lubricating oil in the bearing housing 3 without using an air seal or the like.

[0012]

The bearing according to the present invention is configured as described above, and sprayed lubricating oil filled in the bearing box is supplied from the outside to the inside of the bearing box by an air current flowing from the outside to the inside of the bearing box. So that the lubricating oil in the form of spray filled in the bearing housing does not leak to the outside from the gap in the seal portion.

[Brief description of the drawings]

FIG. 1A is a sectional view of a seal portion of a bearing according to an embodiment of the present invention, and FIG. 1B is a front view of a partition plate thereof.

FIG. 2A is a sectional view of a conventional bearing, and FIG.
FIG. 3 is a detailed view of the seal portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotor shaft 2 Partition plate 3 Bearing box 4 Seal part 5 Drain hole 9 Bevel plate 10 Shield plate

Claims (1)

[Claims] 1. A bearing provided with a seal portion in which the bearing box side and the rotary shaft side slide with respect to each other via a seal member at a portion where the rotating shaft passes through the bearing box. A bearing comprising a swash plate that rotates together with the rotating shaft to generate an airflow from outside to inside the bearing housing.