JPS6151167B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thrust bearing employed in, for example, a vertical shaft water turbine generator or a vertical shaft pump, and particularly relates to a thrust bearing having a backing metal and a base metal.

As is well known, the bearing shoes of this type of thrust bearing, which are generally used, are arranged in parallel around the rotating shaft, and are arranged concentrically with the rotating shaft so as to form a circle as a whole. The shoe is usually supported at a point, for example by a bolt with a spherical head, or by a spring, so that it can tilt or swing in any direction. A thrust bearing equipped with a bearing shoe having such a function is shown in FIG. A runner 2 is fixed to the rotating shaft 1,
It rotates together with the rotating shaft 1. These rotating parts are supported via an oil film by a cast bearing shoe 3 of Babbitt 10 and a pivot 5 that swingably supports this. The bearing shoe 3 and pivot 5 are placed in an oil tank 6 and immersed in lubricating oil 7.
Thrust bearings are constructed in this way, but with the recent increase in the capacity and speed of electrical machinery, bearing shoes with the structures shown in Figures 2 to 4 are generally used as bearing shoes with minimal thermal deformation that can withstand this. It is being That is, the bearing shoe 3 is divided into two parts in the thickness direction, and the upper backing metal 8 in which the Babbitt 10 is cast is divided into two parts.
and a lower base metal 9. The back metal 8 is made of a material with good thermal conductivity to prevent thermal deformation, and the alloy 9 is intended to prevent deformation under load. In order to make full use of this function, it is necessary to prevent the heat caused by the loss generated on the sliding surface between the runner and the bearing shoe from being transmitted to the back metal 8 and further to the base metal 9, causing thermal deformation of the base metal. becomes necessary. In this respect, a heat insulating effect can be expected to some extent due to the contact thermal resistance between the backing metal 8 and the base metal 9, but as shown in FIGS. 2 to 5, the base metal 9 An oil passage groove 11 extending in the direction of rotation of the rotating shaft is provided on the joint surface between the metal and the back metal 8,
A cold oil pipe 12 for supplying cooled lubricating oil is provided between adjacent bearing shoes, so that the cooled lubricating oil cools the sliding surfaces between the runner 2 and the bearing shoe 3, and also prevents oil flow. A structure is adopted in which cooling and thermal insulation are performed through the grooves 11. As a result, 8
The heat insulation effect between the base metal 9 and the base metal 9 becomes very large,
Heat is prevented from being transferred to the base metal 9, and the base metal 9 does not undergo thermal deformation. However, in this structure, the effect greatly changes depending on whether the cooled lubricating oil passes smoothly through the oil passage groove 11 or not. Conventionally, both sides of the back metal 8, that is, both end surfaces perpendicular to the rotational direction of the rotating shaft, are tapered (see part A in Fig. 4).
The end face of the oil passage groove 11 provided on the upper surface of the base metal 9 at the joint surface with the back metal 8 protrudes from the end face of the back metal 8, but in this case, the following problems occur.
In other words, as shown in FIG. 5, since the end surface of the oil passage groove 11 on the oil outlet side protrudes from the end surface of the back metal 8, the cold lubricating oil discharged from the cold oil pipe 12 is absorbed at this outlet portion. It collides with the lubricating oil that has passed through the oil passage groove 11, disturbs the flow, and stagnates, blocking the outlet of the oil passage groove 11.
Therefore, the amount of oil passing through the oil groove 11 is reduced, and the thermal insulation effect between the back metal 8 and the base metal 9 is reduced.

The present invention has been made in view of the above points,
Therefore, the object is to provide a thrust bearing having a bearing shoe that is less subject to thermal deformation.

That is, the present invention achieves the above object by forming the end surface of the groove bottom on the oil outlet side of the oil passage so as to be recessed from the end surface of the back metal.

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

One embodiment is shown in FIGS. 6 and 7. Note that the same parts as in the prior art are denoted by the same reference numerals, and therefore their explanation will be omitted. In the oil passage groove 11 provided at the joint between the backing metal 8 and the base metal 9a, the bottom of the oiling groove 11 on the oil inlet side is stepped and protrudes from the side surface, that is, the end surface, of the backing metal 8, as in the conventional case. However, the end surface of the bottom of the oil passage groove 11 on the outlet side is formed by being cut out so as to be recessed from the end surface of the back metal 8.

By doing this, the flow of oil passing through the oil passage groove 11 is discharged from the cold oil pipe 12 and merges with the flow of oil flowing along the taper of the back metal 8, so that the direction of the flow is changed to that of the oil flowing through the oil passage groove 11. The oil flows along the notched end surface of the groove bottom on the outlet side of the oil groove 11, so that it not only flows smoothly and eliminates oil flow collisions and stagnation, but also the oil flow discharged from the cold oil pipe 12. Due to the merging of the oil passage grooves 11, the passage of oil in the oil passage groove 11 is promoted, and the amount of oil passage increases.

In this way, according to this embodiment, the amount of oil passing through the oil groove can be increased compared to conventional thrust bearings, and the thermal insulation between the backing metal and the base metal, and the cooling effect, are increased, and the heat of the base metal is increased. Deformation is prevented. Furthermore, the base metal is only partially cut out at the bottom of the oil passage groove on the oil outlet side, and its rigidity is not much different from that of the conventional structure. Therefore, sufficient rigidity for preventing deformation can be ensured, so the effects of implementing this embodiment are very large.

As described above, in the present invention, the end face of the groove bottom on the oil outlet side of the oil passage groove provided on the joining surface of the backing metal and the base metal is formed so as to be recessed from the end face of the backing metal. Stagnation of oil at the oil outlet,
Retention is eliminated, and the oil in the oil passage groove flows smoothly, improving the cooling effect, and it is possible to obtain a thrust bearing having a bearing shoe with less thermal deformation.

[Brief explanation of the drawing]

Fig. 1 is a vertical side view showing the vicinity of the thrust bearing of a vertical shaft rotating electrical machine, Fig. 2 is a plan view showing the thrust bearing shoe of a conventional structure, Fig. 3 is a side view showing the thrust bearing shoe, and Fig. 4 is a side view showing the thrust bearing shoe of the conventional structure. 5 is a front view showing the thrust bearing shoe, FIG. 5 is a longitudinal sectional side view showing the area around the thrust bearing, FIG.
The figure is a plan view showing the bearing shoe. 3... Bearing shoe, 8... Back metal, 9, 9a...
Base metal, 11...oil groove, 12...cold oil pipe.

Claims (1)

[Claims] 1 Equipped with a plurality of bearing shoes dividedly arranged around a rotating shaft, and a cold oil pipe disposed between the bearing shoes and supplying cold oil to the bearing shoes, the bearing shoe has a bavit on the upper surface. With a backing fund,
The base metal is joined to the lower part of the backing metal and has an end that protrudes from the backing metal in the rotational direction of the rotating shaft, and has an oil passage groove extending in the rotational direction of the rotating shaft on the surface where the backing metal and the base metal are joined. 1. A thrust bearing comprising: an end surface of the groove bottom on the oil outlet side of the oil passage groove is formed to be recessed from an end surface of the backing metal.