JPS5847597B2 - Thrust bearing lubrication device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thrust bearing lubrication device installed in a water turbine, a water turbine generator, etc., and more particularly to a thrust bearing lubrication device suitable for preventing poor lubrication when starting and stopping a main engine. .

Generally, a thrust bearing attached to a vertical shaft water turbine generator is composed of a plurality of fan-shaped thrust pieces arranged in a circle around a rotating shaft and supported by a pivot or a spring, and a housing that holds the thrust pieces.

Then, by sending pressure oil into the gap between the thrust bearing and the rotating shaft sliding part using a pump, etc., and constantly forming a wedge-shaped viscous oil film, the weight of the rotating part of the main engine or the water thrust acting on the main engine is It supports bearing loads such as the above, reduces starting torque, and prevents damage to sliding surfaces.

In recent years, with the increase in the capacity of individual water turbines or water turbine generators, the load capacity of thrust bearings has also tended to increase. Therefore, it is necessary to improve the reliability of lubrication devices such as oil supply pumps and ensure reliable lubrication of bearing sliding surfaces. There is a need to.

When the rotational speed reaches the rated value, the inclination of the thrust piece with the pivot etc. as the fulcrum becomes constant, and a stable wedge-shaped oil film is formed.

For this reason, a lubricating device such as an oil supply pump generally operates to supply oil to the bearing sliding surface only when the main engine is started or stopped when the rotational speed changes.

However, if an abnormality occurs in the lubrication system due to a failure of the oil supply pump, etc., problems such as seizure or extreme wear may occur due to the inability to supply oil and poor lubrication.If the damage is severe, the thrust bearing σ) must be replaced. This is extremely uneconomical.

Furthermore, if the power supply to the refueling pump or the like is stopped due to a power outage or the like, refueling is similarly disabled and the main engine cannot be operated.

The present invention was devised to solve these conventional difficulties, and its purpose is to provide a thrust bearing lubrication device that can completely prevent lubrication failure when starting and stopping the main engine. be.

The present invention connects an oil supply mechanism to the sliding surface of a thrust bearing via a check valve, and when the pressure of lubricating oil supplied to the sliding surface from the main lubricating device falls below a specified value for a certain period of time, Furthermore, the oil supply mechanism is operated to supply oil to the sliding surface to prevent poor lubrication.

The present invention will be described below based on an illustrated embodiment.

In the figure, 1 is a rotating shaft of a main engine that rotates in the direction of the arrow, and this rotating shaft 1 is rotatably supported by a thrust bearing 2.

The thrust bearing 2 includes a plurality of fan-shaped thrust pieces 3 arranged circularly around the rotating shaft 1, and a pivot 4 that connects the thrust pieces 3 with each other.
The thrust piece 3 is supplied with oil from an oil supply pump 9 through an oil supply pipe 6 having check valves 7 and 8, and is configured to prevent backflow. ing.

A communication pipe 10 and an oil pipe 11 are connected to the oil pipe 6 located between the check valves 7 and 8, respectively, as shown in the figure.
At the end of the communication pipe 10, there is a pressure switch 12 for detecting an abnormality in the oil supply pressure in the oil supply pipe 6, and at the end of the oil supply pipe 11, a pressure switch 12 is installed.
An oil supply mechanism 13 is provided for supplying oil to the thrust piece 3 when the supply oil pressure becomes abnormal.

The oil feeding mechanism 13 includes a cylinder 14, an operating cylinder 15, a control valve 16, an air tank 17, an air compressor 18, and the like.

As shown, the cylinder 14 is formed to have a smaller diameter than the operating cylinder 15, and is connected to the operating cylinder 15 via a bolt or the like.

The piston 19, which is slidably inserted into the cylinder 14 while keeping it liquid-tight, is connected to the operating piston 20 in the operating cylinder 15, and is slid forward in the cylinder 14 by the sliding of the operating piston 20. room 14
The lubricating oil in a can be supplied to the thrust bearing 2 side.

This lubricating oil is prevented from flowing back toward the cylinder 14 by the check valve 8, so that the amount of lubricating oil on the sliding surface of the bearing does not decrease.

On the other hand, an oil leakage reservoir 21 is connected to the chamber 15a of the operation cylinder 15, and the operation piston 20 is connected to the chamber 15a.
An air tank 17 in which compressed air is stored by an air compressor 18 is connected via a control valve 16 to a chamber 15b of the cylinder 15 separated from the cylinder 5a.

This control valve 16 operates upon receiving an operation command from a sequence circuit 22 connected to the pressure switch 12, and supplies compressed air in the air tank 17 to the chamber 15b to operate both pistons 19 and 20. It is configured.

The control valve 16 is operated by a precharged battery (not shown).

Next, the effect will be explained.

When the main lubricating device such as the oil supply pump 9 is operating normally, the pressure oil sent by the oil supply pump 9 is transferred to the oil supply pipe 6.
The oil is press-fitted into the sliding surface of the thrust piece 3 and the rotating shaft 1 through the oil, forming a wedge-shaped viscous oil film, and the main engine is operated steadily.

When an abnormality occurs in the main lubricating system due to the inoperability of the oil supply pump 9 due to a power outage, the pressure switch 12 detects an abnormality in the pressure of the pressure oil, that is, the oil pressure is below a specified value for a predetermined period of time. Sequence circuit 2
2 is activated, and the control valve 16 is activated in response to the command.

Then, the compressed air stored in the air tank 17 by the air compressor 18 is sent to the chamber 15b of the operating cylinder 15, the piston 19 and the operating piston 20 rise, and the pressure oil stored in the chamber 14a is thrust. It is supplied to the bearing 2.

This eliminates poor lubrication.

It goes without saying that the area ratio between the piston 19 and the operating piston 20 is set in advance, and the supply oil pressure of the lubricating oil in the chamber 14a is set as a set value.

When the main engine starts up and reaches the required speed, the control valve 16 is reset by a command from the sequence circuit 22, and the compressed air in the chamber 15b is discharged.

Next, when the oil supply pump 9 operates normally and starts supplying oil, the piston 19 and the operating piston 20 are pushed down, and the chamber 14a is filled with lubricating oil.

Then, oil is supplied to the bearing side.

As explained above, this embodiment provides the following effects.

(1) Even if the main lubrication system malfunctions due to a power outage, etc., the oil supply mechanism supplies pressurized oil to the bearings, so there is no lubrication failure and the reliability of thrust bearings can be improved. .

(2) The size of the cylinder can be small enough to supply oil for a short period of time when the main engine is started or stopped.

Therefore, the oil feeding mechanism can be made smaller.

(3) If the cylinder's operating fluid is used as pressurized water, compressed air, or oil, which is used in the existing equipment, there is no need for a new operating fluid source device, and only a slight change is made to the existing equipment. It is economical to simply add

The present invention has been described above based on the preferred embodiments, but according to the present invention, it is possible to completely prevent poor lubrication when starting and stopping the main engine.

[Brief explanation of drawings]

The drawing is a system diagram showing one embodiment of the present invention. 2... Thrust bearing, 3... Thrust piece,
4... Pivot, 6... Oil pipe, 7,
8...Check valve, 9...Refueling pump, 1
2...Pressure switch, 13...Oil feeding mechanism.

Claims (1)

[Scope of Claims] 1. A lubricating device for a thrust bearing that sends lubricating oil from an oil supply pump to a sliding surface of a thrust bearing through an oil pipe having a check valve, wherein A thrust bearing characterized in that an oil feeding mechanism is connected through a stop valve, and the oil feeding mechanism sends pressure oil to the sliding surface when the oil pressure in the oil feeding pipe becomes abnormal. lubricating device. 2. The oil feeding mechanism includes a cylinder communicating with the oil feeding pipe, a piston slidably inserted into the cylinder, an operation cylinder connected to the cylinder, and a cylinder connected to the piston and slidably inserted into the operation cylinder. The invention comprises an operating piston inserted into the operating piston, a device for supplying operating fluid for operating the operating piston to the operating cylinder, and a control valve for controlling the supply of the operating fluid. A lubricating device for a thrust bearing according to scope 1. 3. The thrust bearing lubrication device according to claim 2, wherein the oil feed pipe is provided with a pressure switch that detects the oil pressure in the oil feed pipe and provides an operating signal to the control valve.