JPH0972491A - Lubricating oil discharge structure for bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the lubricating oil discharge structure for a bearing to suck and discharge lubricating oil through simple constitution and reduce a cost and the size of the whole of a device. SOLUTION: A ball bearing 30 to support the shaft end on the turbine 12 side of the rotary shaft 20 of a gas turbine 10 is disposed in a bearing containing space 40 and a seal space 50 is formed between the bearing containing space 40 and the turbine 12. The bearing containing space 40 is connected to the nozzle 61 of an ejector 60 through an air discharge passage 41 and an ejector feed passage 42. A discharge oil hole 43 opened to the lower part of the bearing containing space 40 is connected to the suction chamber 62 of an ejector through a discharge oil line 44. Compressed air fed from an air compressor 11 to a seal space 50 through a compressed air feed passage and flowing through a labyrinth packing 32A to the bearing containing space 40 is injected through the nozzle 61 of the elector 60 and lubricating oil 1 in the bearing containing space 40 is sucked through the discharge oil hole 43 and the discharge oil line 44.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for discharging lubricating oil supplied to a bearing supporting a rotary shaft of a gas turbine from a housing space of the bearing.

[0002]

2. Description of the Related Art As a lubricating structure for a bearing that supports a rotating shaft, there is a lubricating structure in which a lubricating oil stored in a tank is pumped by a pump and sprayed, and the lubricating oil is again collected in the tank and circulated.

In a turbine or the like which requires an airtight structure at the bearing portion of the rotating shaft, an airtight shield wall is provided on the turbine side of the bearing between the casing and the rotating shaft via a sealing member such as a labyrinth packing. If the opposite side of the bearing and the bearing is on the opposite side, it is sealed by a casing or a cover member to form a closed space, and the bearing is arranged in this closed space (bearing housing space). The lubricating oil supplied to the bearings in the bearing accommodating space accumulates in the lower portion of the bearing accommodating space, and the accumulated lubricating oil is dropped by gravity through the oil drain hole formed in the lower portion of the bearing accommodating space. Alternatively, it is configured to be discharged by being sucked by a mechanical pump, collected in a tank, and used in a circulating manner.

[0004]

However, in the case where the lubricating oil is discharged by utilizing the gravity fall, the difference in height is inevitably required before and after the discharge oil passage due to its structure, and the structure is regulated by this. Therefore, there is a problem that the rational design is hindered, and when the oil temperature of the lubricating oil is low and the viscosity is high, the discharge capacity is deteriorated.

Further, in the case of sucking the lubricating oil by sucking it with a mechanical pump, the pump hinders the downsizing of the entire apparatus (gas turbine) and causes a cost increase, and further, the mechanical rotating portion has a lifespan. Therefore, there is a problem that maintenance is troublesome because replacement is required at regular intervals.

The present invention has been made in order to solve the above problems, and it is possible to suck and discharge lubricating oil with a simple structure, which contributes to cost reduction and overall size reduction of the bearing. The purpose is to provide an oil drainage structure.

[0007]

A lubricating oil discharge structure for a bearing according to the present invention, which achieves the above object, has a bearing housing space in which the lubricating oil supplied to a bearing supporting a rotating shaft of a gas turbine is isolated from the turbine. An oil drain hole is formed in the lower part of the bearing housing space, and the oil drain hole is formed in the ejector that is sucked by the compressed air supplied from the air compressor of the gas turbine. It is characterized by being connected through a road.

A seal space is formed between the bearing housing space and the turbine, the seal space being separated from the turbine by a primary seal member and the bearing space being separated from the bearing space by a secondary seal member. Compressed air is introduced from the air compressor to perform a sealing action, and compressed air from the seal space to the bearing housing space via the secondary seal member is supplied from the bearing housing space to the ejector. It is characterized in that it is configured to operate by suction.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a conceptual configuration diagram of a gas turbine including a lubricating oil discharge device which is an embodiment of a lubricating oil discharge structure for a bearing according to the present invention.

The illustrated gas turbine 10 includes an air compressor 11
And a turbine 12 are arranged in series on the same rotary shaft 20, and are provided with a combustor 13 to which compressed air from an air compressor 11 and fuel gas from a fuel supply device (not shown) are supplied. The compressed air and the fuel gas from the compressor 11 are mixed and burned in the combustor 13, and the combustion gas of high temperature and high pressure drives the turbine 12 to obtain a rotational force. The rotating shaft 20 is connected to a driven device such as a generator (not shown).

The shaft end of the rotary shaft 20 on the turbine 12 side is provided with a casing 1 via a ball bearing 30 as a bearing.
3, the casing 13 on the outer end side of the ball bearing 30 is hermetically sealed.

On the inner surface of the casing 13 on the turbine 12 side of the ball bearing 30, a partition wall 3 is provided between the ball bearing 30 and the rotary shaft 20.
1 and 32 are provided in double, a labyrinth packing 31A as a primary seal member is interposed between the partition wall 31 and the rotary shaft 20, and a secondary wall is provided between the partition wall 32 and the rotary shaft 20. Labyrinth packing 32A as a seal member
Is interposed.

As a result, the partition 32 and the casing 13 form a bearing accommodating space 40 as a bearing accommodating space, the ball bearing 30 is disposed in the bearing accommodating space 40, and the bearing accommodating space 40 on the turbine 12 side. Further, the partition space 31 and the partition wall 32 form a seal space 50.

Lubricating oil stored in a lubricating oil tank is sprayed onto the ball bearing 30 by a lubricating oil supply mechanism (not shown). An oil drain hole 43 is formed downward in the lowermost part of the bearing housing space 40, and is used to lubricate the ball bearings 30 and collect in the lower part of the bearing housing space 40.
Is discharged through this oil drain hole 43. An oil drain pipe line 44 is connected to the oil drain hole 43,
The other end is connected to the suction chamber 62 of the ejector 60.

An air exhaust passage 41 is connected to the upper part of the bearing accommodating space 40, and compressed air flowing in from a seal space 50, which will be described later, via the labyrinth packing 32A to the outside via the air exhaust passage 41. It is supposed to be discharged. The ejector supply path 42 is branched from the middle of the air discharge path 41.
2 is connected to the nozzle 61 of the ejector 60.

The ejector 60 includes a nozzle 61 and a suction chamber 6
2 is configured to suck the fluid from the conduit that is connected to and opened in the suction chamber 62 by the fluid ejected to the suction chamber 62, and the compressed air supplied through the ejector supply passage 42 enters the suction chamber 62 from the nozzle 61. Ejection, by which the suction chamber 6
The lubricating oil 1 is adapted to be sucked from the oil drain pipe line 44 connected to 2.

Compressed air having a predetermined pressure is supplied from the air compressor 11 to the sealed space 50 through a compressed air supply passage 51. The pressure of the compressed air is set to be higher than the pressure in the adjacent turbine 12, whereby the compressed air leaks to the outside through the labyrinth packings 31A and 32A on both sides of the seal space 50, and the high temperature in the turbine 12 is generated. Combustion gas is sealed space 50
It acts so as to prevent the bearing accommodating space 40 from entering through the bearing. Further, the air leaking from the seal space 50 to the turbine 12 side via the labyrinth packing 31A also cools the blades of the turbine 12.

Thus, in the above structure, the lubricating oil 1 supplied to the ball bearing 30 and accumulated in the bearing housing space 40 is discharged through the lower oil discharge hole 43.
The ejector 60 acts to suck the lubricating oil 1 and accelerate its discharge. That is, the bearing housing space 40 from the seal space 50 via the labyrinth packing 32A.
The compressed air that has leaked to the outside is discharged to the outside through the air discharge passage 41, and a part of the compressed air is supplied to the ejector 60 through the ejector supply passage 42 and is ejected from the nozzle 61 and connected to the suction chamber 62. The lubricating oil 1 accumulated in the lower portion of the bearing housing space 40 is sucked through the drainage oil passage 44 to prompt its discharge.

Since the lubricating oil collected from the bearing housing space 40 by the ejector 60 is mixed with air, it is separated from the air by an oil separator (not shown) and returned to the lubricating oil tank for circulation. is there.

As described above, according to the structure in which the ejector 60 acting by utilizing the compressed air from the air compressor 11 recovers the lubricating oil 1 accumulated in the bare link accommodation space 40, there is no mechanically movable part. In addition, it is possible to configure with small number of failures and small size and at low cost, and also with less restriction on the entire structure, it is possible to configure freely.

[0021]

As described above, according to the lubricating oil discharge structure of the bearing according to the present invention, the lubricating oil supplied to the bearing supporting the rotating shaft of the turbine is supplied from the air compressor of the gas turbine. The compressed air can be sucked and discharged by an ejector that operates by suction, and the lubricating oil discharge capacity can be increased with a simple structure. It is possible to reduce the cost and downsize the entire device.

Further, by using the pressurized air from the seal space formed on the turbine side of the bearing housing space to the bearing housing space as the working fluid of the ejector, a more rational configuration can be achieved, further reducing the cost. Therefore, the entire device can be downsized.

[Brief description of drawings]

FIG. 1 is a conceptual configuration diagram of a gas turbine using an embodiment of a lubricating oil discharge structure for a bearing according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lubricating oil 10 Gas turbine 11 Air compressor 12 Turbine 13 Combustor 20 Rotating shaft 30 Ball bearing (bearing) 31A Labyrinth packing (primary seal member) 32A Labyrinth packing (secondary seal member) 40 Bearing accommodating space (bearing accommodating space) 43 Oil drain hole 44 Oil drain pipe 50 Seal space 60 Ejector

Claims (2)

[Claims] Claim: What is claimed is: 1. Lubricating oil supplied to a bearing that supports a rotary shaft of a gas turbine is discharged from a bearing housing space isolated from the turbine, and an oil drain hole is formed in a lower portion of the bearing housing space. As well as
A lubricating oil discharge structure for a bearing, wherein the oil discharge hole is connected to an ejector suctioned by compressed air supplied from an air compressor of the gas turbine via an oil discharge pipeline. 2. A seal space is formed between the bearing accommodating space and the turbine, the seal space being separated from the turbine by a primary seal member and separated from the bearing accommodating space by a secondary seal member. Compressed air is introduced from the air compressor to perform a sealing action, and compressed air from the seal space to the bearing housing space via the secondary seal member is supplied from the bearing housing space to the ejector. The lubricating oil discharge structure for a bearing according to claim 1, wherein the lubricating oil discharge structure is configured to be suction-operated.