JPS587876B2 - Guide bearing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a guide bearing for a vertical shaft type rotating machine, and more particularly to a guide bearing for a vertical shaft type water turbine and generator having an oil tank that rotates together with the shaft.

In a guide bearing with a rotating oil tank, the lubricating oil inside the oil tank begins to rotate as the oil tank rotates due to its viscosity, and the centrifugal force caused by this rotation causes the shape of the free surface in contact with the atmosphere to change as shown in Figure 1. Draw a parabola of revolution like this.

In other words, the lubricating oil necessarily moves away from the bearing surface.

For this reason, the method of supplying lubricating oil to the bearing surface is as shown in Figure 1, by installing an oil sampling pipe 16 on the outer circumference of the oil tank, using the rotational force of the oil to draw the oil, guiding it to the oil tank 17 above the shaft cost, and supplying the oil naturally. A common method is to use falling force to supply oil to the bearing surface.

In rare cases, there is also a system in which oil is supplied directly to the bearing surface from an oil sampling pipe (not shown) provided on the outer circumferential side of the oil tank 3.

In the figure, A is the oil level during operation, and B is the oil level when stopped.

However, since these systems are based on the rotational force of the oil in the oil tank, problems such as insufficient lubrication when starting the rotating shaft or an abnormal rise in the oil level in the upper oil tank during overspeed operation exceeding the rated rotation speed may occur. The major drawback is that it lacks stability as a device.

The purpose of the present invention is to reduce the isobaric action of the buttful plate and the rotating part of the oil, so that the rotational state of the shaft (
An object of the present invention is to provide a highly stable bearing device that is capable of keeping the surface of lubricating oil around the bearing horizontal even when the bearing is stopped (including when the bearing is stopped).

The present invention provides a guide bearing in which an oil tank rotates.
The lubricating oil inside the oil tank rotates, and as the oil tank rotates, the surface of the oil tank traces a parabola of rotation and moves away from the bearing surface, which is an inevitable drawback of a bearing device. By reducing and restricting the free surface of the lubricating oil with a surface area, the surface of the lubricating oil around the bearing is kept almost horizontal under any rotating state of the shaft (of the oil tank), resulting in stable (reliable) contact with the bearing surface. This made it possible to supply lubricating oil (high cost).

FIG. 2 shows an embodiment of the present invention.

The oil tank 3 is fixed to the rotating shaft 1 and rotates therewith.

The bearing 2 is supported by a bearing support 5 and has a bearing surface 2a on a surface corresponding to the rotating shaft 1.

A plurality of ribs 8 are attached radially to the bearing 2, and a buff-full plate 6 is fixed to the ribs 8 at a portion facing the lower part of the oil tank 3.

On the other hand, a fixed cylinder 7 is fixed to a portion facing the outer circumference of the oil tank 3.

The baffle plate 6 exists in the lubricating oil 15, and the fixed cylinder 7 is installed so as to extend above the free surface of the lubricating oil 15 when the lubricating oil 15 is at rest.

An opening 13 is provided between the full plate 6 and the fixed cylinder 1.
An opening 14 is provided between the buff-full plate 6 and the lower end of the bearing 2.

In a conventional bearing (one without the full plate 6, fixed cylinder 7, and rib 8), the lubricating oil 15 is rotated from the part in contact with the oil tank 3 as the oil tank 3 (= rotating shaft 1) rotates. Initially, all of the lubricating oil will eventually rotate, and the oil surface will move away from the cylindrical portion of the bearing 2, tracing the parabolic surface of rotation.

However, when the baffle plate of the present invention is installed, the lubricating oil in contact with the lower part of the oil tank 3 is given a rotational force due to its viscosity, and the oil between the oil tank 3 and the baffle plate 6 rotates and generates centrifugal force. Opening 13 provided on the outer diameter side
Become more open.

At the same time, the oil drawn to the outer surface by centrifugal force is continuously replenished through the opening 14 provided on the inner diameter side, so the oil above and below the buttful plate 6 only circulates steadily. Static pressure remains almost constant.

That is, the oil is drawn toward the outer circumference by the centrifugal force at the lower part of the buffle plate 6 and circulates back to the lower part of the buffle plate 6 through the openings 13 and 14.

It is known from experimental results that in this state, the distribution of static pressure above and below the baffle plate 6 is almost the same as shown in FIG. 3C.

That is, the line C shows the static pressure when the buffle plate is provided, and it can be seen that the static pressure distribution is significantly more stable than the static pressure distribution shown by the line D when the buffle plate is not provided.

Note that V, W, X, and Y indicate the positions inside the buff-full plate, outside the buff-full plate, outside the fixed cylinder, and inside the oil tank, respectively.

Line E shows the static pressure distribution between the outside of the fixed circumference and the inside of the oil tank.

This means that the oil level above the baffle plate is kept approximately horizontal.

On the other hand, the influence of the oil rotating in contact with the outer circumferential side of the oil tank 3 is as follows.
This can be prevented by providing the fixed cylinder 7.

That is, the inside of the cylinder 7 does not rotate at all, and can maintain a substantially horizontal surface due to the equal pressure action of the buff-full plate 6.

The oil maintained horizontally is stably supplied to the bearing surface 2a through the oil supply hole 9.

The surface of the oil between the fixed cylinder 7 and the rotating oil tank 3 forms a rotating parabolic surface due to rotation, but by narrowing the distance between the cylinder 7 and the oil tank 3, the difference in height between the inside and outside of the oil surface is reduced. Therefore, the displacement of the inner oil level can be reduced.

In this way, a highly reliable oil self-contained guide bearing can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional oil tank rotating type self-contained guide bearing device, Fig. 2 is a sectional view of an oil tank rotating type self-contained guide bearing device of the present invention, and Fig. 3 is a sectional view of an oil tank rotating type self-contained guide bearing device. FIG. 3 is a diagram showing the state of oil pressure inside the oil self-contained guide bearing. 1...Rotating shaft, 2...Bearing, 3...
...Oil tank, 4...Oil tank cover, 5...
Bearing support, 6... Bought full plate, 7...
・・・Fixed cylinder, 8... Rib, 9...
Oil supply hole, 10...cover.

Claims (1)

[Claims] 1. In a guide bearing device for a vertical shaft rotating machine having a rotating shaft and an oil tank that is fixed to the rotating shaft, rotates integrally with it, and contains lubricating oil, the bearing is arranged opposite to a lower surface member and an outer peripheral member of the rotating oil tank. A non-rotating buttful plate and a fixed cylinder are provided, and the buttful plate and fixed cylinder are fixed by a plurality of ribs provided on the outer periphery of the bearing. A guide bearing device characterized by forming an opening through which lubricating oil circulates.