JPS598793A - Journal bearing - Google Patents

Abstract

PURPOSE:A highly efficient journal bearing, prepared by providing an introductory apparatus for incorporating a fine material in an oil supply system to the bearing, capable of reducing the bearing loss and bearing temperature without causing seizure. CONSTITUTION:A journal bearing 2, prepared by providing a container 10 for incorporating a fine material through an oil supply line 6 to an oil film 9 of the journal bearing 2 to adjust the flow of the turbulent oil film 9 and reduce the bearing loss by acting as rolls between the shaft 1 and the journal bearing 2 and a filter 11 for recovering the fine material, and capable of preventing the damage of pumps, etc. Soft iron powder with a low content of carbon, a high polymer material, etc. is selected as the fine material, and the size thereof is preferably 100-150mum diameter.

Description

[Detailed description of the invention] The present invention relates to journal bearings.

FIG. 1 shows a general journal structure. Shaft 1 is
It is inside the bearing 2, and a bearing material such as white metal is bonded to the inside of the bearing 2 to improve sliding. −
Also, oil is supplied from the oil tank 4 to the oil supply hole 6 of the bearing by the pump 5.
sent to. This is sucked through the gap 7 between the shaft 1 and the bearing 2, and a part of it passes through the oil drain hole 8 and returns to the oil tank 4, but the rest flows under the bearing and an oil film 9 between the shaft 1 and the bearing 2.
1r: Designed to carry full bearing load.

Further, in the vicinity of the oil film 9, oil shear causes a force acting in the direction of the entire rotation of the bearing, and this causes a large proportion of the mechanical loss as a bearing loss.

In recent years, steam turbines have become larger and the diameter of the journal has increased significantly, but this has also increased the circumferential speed, causing oil to move from laminar flow to turbulent flow.

FIG. 2 shows the relationship between peripheral speed V and bearing loss. In a range where the circumferential speed is low, the lubricating oil is in a laminar flow, so the loss increases along curve A, but when the flow becomes turbulent, the loss increases rapidly and becomes like curve B. In some modern turbines, losses can be twice as much when comparing turbulent flow and laminar flow. Reducing this loss is of substantial benefit and necessary to provide highly efficient turbines.

In addition, the reduction in bearing loss reduces the amount of heat generated, which prevents the bearing material from melting and is also effective in preventing seizure of the bearing.

Therefore, the purpose of the present invention is to reduce the total bearing loss and to prevent seizure of the bearing. It is possible to provide a full range of journal bearings.

FIG. 3 shows a journal bearing that is an embodiment of the present invention. In the figure, minute objects (1) are mixed into the oil supply line from a container 10, pass through a bearing, and are collected in a filter 11. By doing this, damage to the pump can be prevented.

If a minute object enters the oil film 9 of the bearing, the flow of the turbulent oil film is adjusted, and it is thought that the bearing loss is reduced because it acts as a roller between the shaft and the bearing. It has been confirmed through experiments that the temperature of the bearing surface decreases and the loss decreases.

FIG. 4 shows the temperature change on the surface of the bearing metal when iron powder with a particle diameter of 150 μm is placed in the bearing. The temperature begins to drop at the same time as the iron powder is introduced, and the temperature drop ΔT becomes about 1 Or. Normally, the bearing metal surface temperature is approximately 100 to 110'C.
Therefore, the temperature reduction rate is about 10%. Moreover, the change in bearing loss at this time was shown in FIG. The loss also decreased at the same time as the iron powder was added, resulting in a decrease of about 5%.

In addition, it is preferable that the minute objects to be mixed in are soft objects that will not cause large scratches on the shaft or bearing material. The microscopic objects selected include fine iron powder and polymeric materials with a low content of carbon. The size of this minute object is 100 to 150 μm in diameter.
is considered appropriate. If it becomes even larger, there is a risk that the bearing surface and journal surface will be scratched and the bearing characteristics will be impaired.

FIG. 6 also shows another embodiment of the present invention, in which a minute object 12 is mixed in advance into the oil tank 4, suspended in oil, and supplied to the inside of the bearing.

This minute object is an organic material with a specific gravity similar to that of oil, and is good for preventing it from remaining at the bottom of the oil tank and damaging the pump kTM.

As described above, according to the present invention, by mixing minute objects into the IklII oil, the total bearing loss is reduced and the bearing temperature is also lowered, thereby providing a highly efficient and safe journal bearing without seizure. It has the effect of being able to do it.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of a conventional journal@bearing, Figure 2 is an explanatory diagram of bearing loss, Section 3 is a schematic diagram of a journal bearing according to an embodiment of the present invention, and Figure 4 is a diagram after iron powder is added. Figure 5 shows the change in bearing metal temperature. Figure 5 shows the change in bearing loss after iron powder is added.
FIG. 6 is a schematic diagram of a journal bearing according to another embodiment of the present invention. 1... Yaft, 2... Bearing, 3... Bearing material,
4... Oil tank, 5... Pump, 6... Oil supply hole,
7... Gap, 8... Oil drain hole, 9... Oil film, 1o.
...Refueling container, 11...Filter, 12...Contaminants. Yume JE7J, BU/Lde Pig lpY Pig

Claims (1)

[Scope of Claims] 1. A journal bearing, characterized in that the journal bearing is fully equipped with a minute object feeding device for mixing minute objects into the oil supply system for the bearing. 2. A journal bearing according to claim 1, characterized in that the minute object is iron powder. 3. The journal bearing according to claim 1, wherein the minute object is an organic substance.