JPS5947165B2 - Thrust bearing device for rotating machines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thrust bearing device for a rotating machine, and particularly to a rotating machine suitable for use in high-speed vertical shaft rotating electric machines such as high-speed vertical shaft water turbine generators and vertical shaft generator generators. The present invention relates to a thrust bearing device.

In general, this type of thrust bearing device, as shown in FIG. 1, includes a collar 2 formed integrally with a rotating shaft 1, and a plurality of bearings that slidably support a bearing runner 3 fixed to the collar. The collar 2, the bearing runner 3, the bearing pad 4, and the guide bearing 5 are coated with lubricating oil 6!
- It is housed in a filled oil tank T, and in this state supports and slides the total weight of the rotating parts of, for example, a water turbine generator.

Is this the inner circumference of the oil tank □? The lubricating oil 6a between A and the inner peripheral part 2a of the collar 2 rises along the side surface of the inner peripheral part 2a of the collar as shown by the broken line in the figure due to the rotation of the collar 2, causing oil leakage. To prevent this, an oil discharge hole 8 is provided from the inner circumferential side to the outer circumferential side of the collar 2 to discharge the lubricating oil 6a. By the way, the bearing loss that occurs in this type of thrust bearing device is
The loss can be roughly divided into friction loss that occurs on the sliding surfaces of the bearing runner 3 and the bearing pad 4, and lubricant agitation loss that occurs when the collar 2 and the bearing runner 3 rotate in the lubricant.

These losses are, for example, an output of 400 MVA, 112.5 m, and a friction loss of about 40 OKW in a p, m water turbine generator.
The stirring loss is 10 OKW. However, rotating machines such as water turbine generators and power generators are becoming larger and faster due to economical reasons, and bearing losses are also increasing dramatically.
For example, in a 300MVA) 500, p, m water turbine generator, the bearing loss reaches as much as 6000KW, and about 500KW of that loss is due to stirring loss. This is because the friction loss is proportional to the circumferential speed of the bearing runner 3 to the 1.5th power, whereas the stirring loss is proportional to the circumferential speed to the third power. Therefore, as the circumferential speed of the bearing runner 3 increases, the stirring loss increases significantly. In order to reduce this stirring loss, the collar 2, the guide bearing 5, the bearing runner 3, and the bearing butt 4 must be
In order to provide the oil discharge hole 8 in the collar 2, the upper surface of the bearing runner 3 and the guide bearing 5 should be reduced. Since the dimension H between the lower surfaces of the collar 2 and the bearing runner 3 is required to be approximately 100 ggn, it has been difficult to reduce the contact length between the lubricating oil 6, the collar 2, and the bearing runner 3.

It is possible to reduce the contact length of the collar 2 and reduce agitation loss by passing this oil discharge hole from the inner peripheral surface of the collar to the outer peripheral surface of the bearing runner. It is extremely difficult to align the position of the discharge hole of the bearing runner and the discharge hole of the bearing runner because the discharge hole machining spans two parts, and as a result, the lubricating oil 6a is not sufficiently discharged and there is a risk of oil leakage. was difficult.
As mentioned above, in conventional thrust bearing devices, it is very difficult to reduce stirring loss, and there are concerns that oil leakage may occur if attempts are made to reduce stirring loss.

The present invention has been devised in view of the above points, and an object thereof is to provide a thrust bearing device for a rotating machine with no oil leakage and low stirring loss.

That is, in the present invention, the discharge means is connected to the oil tank by the collar. An oil discharge hole is provided penetrating from the inner circumferential side of the portion where the lubricating oil is stored in the bearing runner to the outer circumferential side of the bearing runner, and an oil discharge hole is provided in the contact area between the collar and the bearing runner where the discharge hole intersects. The above-mentioned object is achieved by forming a part with a width widening means.

The present invention will be explained below based on the illustrated embodiments.

An embodiment of the invention is shown in FIGS. 2 and 3. Note that parts that are the same as those in the conventional model are given the same reference numerals, and therefore their explanations will be omitted. A counterbore 9 and a counterbore 0 are provided in the contact area between the oil discharge hole 8a provided in the collar 2 and the oil discharge hole 8b provided in the bearing runner 3, and from the inner circumferential side of the collar 2 to the outer circumferential side of the bearing runner 3. I made it pass through. By doing this, the axial length of the collar can be shortened and the lubricating oil 6
The contact length between the collar 2 and the bearing runner 3 can be shortened, and even if the oil discharge holes 8a and 8b of the collar 2 and the bearing runner 3 are machined to be misaligned, the penetration of the collar 2 will not be impaired. This ensures that the lubricating oil 6a on the inner circumferential side is discharged. A quantitative trial calculation of the effects of the present invention in this regard is as follows. For example, in the conventional thrust bearing device shown in FIG.
= 220VfL, 12=150mE, H=10071
In the case of 1E, the total height of the collar and bearing runner that are in contact with the lubricating oil is 4707&w, but according to Fig. 2 according to the present invention, the total height is 390u, and the length of contact with the lubricating oil is the same as that of the conventional one. Approximately 80%, reducing stirring loss by approximately 2
It can be reduced by 0%.

Here, 300MV with bearing runner outer diameter 3100Tf1$
Figure 5 shows how the bearing loss of the A-generator-motor changes with changes in rotational speed. The curved line in the figure shows the bearing loss of the conventional guide bearing thrust bearing device, which occurs when the guide bearing pad is soaked in lubricating oil. The curve shows the bearing loss of the thrust bearing device according to the invention shown in FIG. From now on, by creating a structure that reduces the contact length between the lubricating oil and rotating bodies such as the collar and bearing runner, the 500r. p. It can be seen that a considerable difference in loss occurs when m is used, and this is particularly effective for high-speed rotating machines. As more and more large-capacity, ultra-high-speed rotating machines are being planned in the future, adoption of this invention will make it possible to manufacture highly efficient rotating machines. Furthermore, by reducing the axial dimension of the collar, the oil tank can be made smaller, making it extremely economical. Another embodiment of the invention is shown in FIG.

V-shaped grooves 11 and 12 are provided at the contact portions of the oil discharge holes 8a and 8b. In addition, this V-shaped groove 1 is shown in FIG.
1 and 12 are shown superimposed on the counterbore S, , O of the previous embodiment. Even with this, the same effects as those described above can be achieved. Even if either the guide line or the oil discharge hole provided in the bearing runner is made larger than the other, the same effects as those described above will be obtained.

As described above, the present invention provides an oil discharge hole that penetrates the discharge means from the inner circumferential side of the portion where the collar is housed in the lubricating oil in the oil tank to the outer circumferential side of the bearing runner, and that the discharge hole is Since the contact portion between the intersecting collar and the bearing runner is provided with a widening means to widen a portion of the contact portion, the discharge hole can be easily formed without impairing its penetrability, thereby improving lubrication. In addition to smooth oil discharge, the outlet of the discharge hole is placed on the outer circumferential side of the bearing runner, so the axial length of the collar can be shortened, reducing the total length of the collar and bearing runner that come into contact with the lubricating oil. Therefore, it is possible to obtain a thrust bearing device for a rotating machine with no oil leakage and less stirring loss.

[Brief explanation of drawings]

FIG. 1 is a vertical side view showing a conventional thrust bearing device, FIG. 2 is a vertical side view of a thrust bearing device showing an embodiment of the present invention,
FIG. 3 is a perspective view showing the curved exit hole in the contact part;
FIG. 4 is a perspective view of an oil discharge hole in a contact portion showing another embodiment of the present invention, and FIG. 5 is a characteristic diagram showing the relationship between rotational speed and bearing loss. 2... Collar, 3... Bearing runner, 4... Support, 7... Oil tank, 8... Oil discharge hole, 8a... Oil discharge hole, 8b... Oil discharge hole, 9... Counterbore, 10...
・Counterbore, 11... figure-shaped groove, 12... figure-shaped groove.

Claims (1)

[Scope of Claims] 1. A collar formed integrally with a rotating shaft, a bearing runner fixed to this collar, a support body that slides and supports this bearing runner, and these collars, bearing runners, and support body. and an oil tank surrounding the collar and containing lubricating oil, and a thrust of a rotating machine comprising a discharge means for discharging the lubricating oil on the inner circumferential side of the collar into the lubricating oil on the outer circumferential side during rotation. In the bearing device, an oil discharge hole is provided through the discharge means from an inner circumference side of a portion where the collar is housed in lubricating oil in the oil tank to an outer circumference side of the bearing runner;
A thrust bearing device for a rotating machine, characterized in that a contact portion between the collar and the bearing runner where the discharge hole intersects is provided with widening means for widening a portion of the contact portion. 2. The thrust bearing device for a rotating machine according to claim 1, wherein the widening means is formed by providing a counterbore in one or both of the collar and the bearing runner in the contact portion. 3. The thrust bearing for a rotating machine according to claim 1, wherein the widening means is formed by providing a V-shaped groove in one or both of the collar and the bearing runner in the contact portion. Device.