JPH07167132A - Thrust bearing device - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a thrust bearing that can ensure soundness and is easy to maintain and maintain even in a large-capacity rotary electric machine that requires a bearing device with high peripheral speed and high surface pressure. To provide a device. According to the present invention, a stationary plate 16 that supports a rotating shaft of a vertical rotating electric machine used in a water turbine power plant, and the stationary plate 16 are provided.
In a thrust bearing device configured by an elastic body that elastically supports a disc spring 11 as an elastic body and the disc spring
The upper clamp 13 and the lower clamp 14 that sandwich 11 to form the stationary plate 16 and the disc spring 11 that is sandwiched between the upper clamp 13 and the lower clamp 14 apply an initial load and fix the upper clamp 13 and the lower clamp 14. It is characterized by having a countersunk bolt 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thrust bearing device, and in particular, a thrust bearing device having a high surface pressure, a high peripheral speed and a large load, in which the bearing loss is greatly reduced by using a vertical rotating electric machine or the like. Regarding

[0002]

2. Description of the Related Art In recent years, hydroelectric power generation facilities generally continue to increase in capacity at high speed, and the hydraulic machines and generators such as pump turbines and turbines used here are harsh under high speed, high pressure and high load. It has been exposed to driving. In addition, according to the demand for electric power, it is in a state of being quickly started and stopped and operated under various load conditions, and high reliability is required for stable electric power supply.

A thrust bearing device generally used in a vertical shaft type rotating electric machine, for example, a vertical type turbine generator or a pumped-storage generator motor, not only has the weight of the rotating body of the generator and the turbine but also water generated by the operation of the rotating electric machine. It also supports thrust. As a rotating electric machine has a high-speed and large-capacity, water thrust stands up to three times the weight of the rotating body, and the friction loss of the thrust bearing becomes enormous, which is uneconomical in terms of the operating efficiency of the rotating electric machine.

An elastic support structure is generally used as a member for supporting the thrust bearing stationary plate of the thrust bearing device for such a high speed and large capacity rotary electric machine. In a high peripheral speed, heavy load thrust bearing device, increasing the average surface pressure on the thrust surface of the thrust bearing to downsize the device is the only way to reduce enormous bearing loss. In order to improve the basic performance of the thrust bearing, for example, recently, a high-performance thrust bearing formed of a tetrafluoroethylene material, which replaces the white metal of the conventional bearing material (for example, Japanese Patent Application No. 4-96357). Has been proposed and a high surface pressure / low loss thrust bearing has been applied for.

By the way, as an elastic support structure arranged under the thrust bearing stationary plate, an iron-based coil winding spring has been conventionally used. A plurality of coil springs arranged under the stationary plate are elastic springs for multi-point elastic support, such as the effect of suppressing thermal deformation of the stationary plate itself during operation and equalization of load sharing among the plurality of stationary plates. Is an extremely rational structure for supporting heavy-duty thrust bearings. On the other hand, the elastic support structure disposed under the thrust bearing stationary plate used in the thrust bearing device for a vertical rotating electric machine is limited by the following conditions from a water turbine or a pump turbine directly connected to the rotating electric machine.

It is required that the axial displacement due to the increase / decrease of water thrust during the operation of the water turbine runner, that is, the spring constant of the elastic support structure, be a certain value or more. in this case,
Deflection in the axial direction due to changes in water thrust is limited to about several mm. Further, the elastic support structure as the thrust bearing device needs to have a proper spring constant as a vibration system due to a hydrodynamic axial excitation source during operation of the water turbine or the pump water turbine.

The coil-wound springs conventionally used support the thrust bearings and the total thrust bearings in the number arranged under the stationary plate. That is, the amount of bending in the axial direction restricted from the turbine side should be determined by arranging the necessary coil springs in accordance with the load-bending relationship that each coil spring bears.

In other words, a plurality of coil springs arranged under the high surface pressure thrust bearing stationary plate can no longer be realized as an elastic support structure having an appropriate spring constant.

Therefore, an object of the present invention is to provide a large-capacity rotary electric machine which requires a bearing device with high peripheral speed and high surface pressure.
An object of the present invention is to provide a thrust bearing device that can ensure soundness and is easy to maintain.

[0010]

However, in recent years, when a high peripheral speed and large load thrust bearing is required, the surface pressure of the thrust bearing is increased to reduce the bearing loss, so that the conventional coil spring can be used. Now it is no longer possible to increase the number of coil springs. That is, conventional thrust bearings with an average surface pressure of about 50 kg / cm ² could be handled by arranging the required number of coil springs.
In the thrust bearing device exceeding kg / cm ² , by arranging the conventional coil spring, it becomes impossible to increase the flexure as an elastic support and to secure the total spring constant. Even if it is arranged, the spring is not provided between the coil windings. As a result, there is no bending and the elastic characteristics are lost, and it has become impossible to fulfill the role of the elastic support structure as a very high peripheral speed and large load thrust bearing device.

[0011]

DISCLOSURE OF THE INVENTION The present invention relates to a thrust bearing device composed of a stationary plate for supporting a rotary shaft of a vertical rotating electric machine used in a hydraulic turbine power plant and an elastic body for elastically supporting the stationary plate. , A disc spring as an elastic body, an upper clamp and a lower clamp that sandwich the disc spring to form a stationary plate, an initial load is applied to the disc spring sandwiched between the upper clamp and the lower clamp, and the upper clamp and the lower clamp And a countersunk bolt for fixing the clamp.

The upper clamp and the lower clamp are fixed by using a stopper plate instead of the countersunk bolt. Also, a sliding pad made of tetrafluoroethylene material filled with glass fiber or molybdenum disulfide, which is provided on the stationary plate side that receives axial surface pressure from the rotating shaft, and a groove portion provided on the stationary plate and fitted with the sliding pad. It is characterized by having and

[0013]

In the thrust bearing of the present invention, an initial load is applied to the disc springs sandwiched between the upper clamp and the lower clamp as stationary plates, and then these are fixed by the fittings that fit with the grooves provided in the disc bolts or clamps. By doing so, the spring constant per unit area can be significantly improved. Further, by providing the replaceable sliding pad and the groove that fits with the sliding pad, it is possible to shorten the work process of maintenance and inspection of the rotating electric machine.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a sectional view showing elastic support by a disc spring of a thrust bearing device of the present invention. As shown in FIG. 1, a plurality of disc springs 11 for obtaining a predetermined spring constant are arranged in a state of overlapping in the axial direction of the thrust bearing device, and a disc spring for supporting a thrust load and giving an initial load.
An upper clamp 13 and a lower clamp 14 are arranged on the upper and lower surfaces or one of the sides via a seat plate 12, and these clamps are configured to apply an initial load to the disc spring 11 with a disc bolt 15.
In addition, after applying an initial load to the disc spring 11, a plurality of stationary plates 16
The upper and lower surfaces of the upper and lower clamps are machined in order to keep the axial heights of the plurality of above-described components arranged below constant.

The number of disc springs 11 arranged in the axial direction depends on the construction method (arrangement of the upper and lower surfaces of the disc springs 11) and the disc springs.
The inner and outer diameters and the thickness of 11 themselves can be designed almost freely in order to obtain a predetermined spring constant per spring and to satisfy the allowable load.

In this embodiment, when a disc spring having the same outer diameter and height as the conventional coil spring shown in FIG. 6 is used, the elastic body characteristic diagram shown in FIG. 7 is obtained.
That is, the allowable load is 50% higher than that of the conventional coil spring characteristic line (a), as shown by the disc spring characteristic line (b) of the thrust bearing device using the disc spring of the present invention having improved load resistance. An example is shown.

As a result, the spring of the present invention arranged under the stationary plate of the stella bearing can be arranged in exactly the same manner as the conventional coil spring as shown in FIG. 6, and the allowable load is in the case of the conventional coil spring. Since it is improved by 50%, it is possible to provide an elastic support structure capable of supporting a thrust bearing having an average surface pressure of 80 to 90 kgf / cm ² class with an appropriate spring constant.

Next, a second embodiment will be described with reference to FIG. As shown in FIG. 2, a clasp 17 is used between the upper clamp 13 and the lower clamp 14 to apply an initial load to the disc spring 11, and a clasp is provided on the outer circumference of the upper clamp 13 and the inner circumference of the lower clamp 14.
A circumferential groove 18 that can carry the initial load via 17
To provide.

With such a configuration, the first embodiment
The same effect as can be obtained. Further, a third embodiment will be described with reference to FIG. FIG. 3 is a perspective view of an essential part showing an embodiment of the stationary plate of the thrust bearing device of the present invention, and shows a procedure for assembling and disassembling the stationary plate 16. Each of the sliding pads 19 is manufactured independently,
The stationary plate base metal 20 is provided with a groove 18 for inserting the sliding pad 19 on the sliding surface side with an iron-based material. Sliding pad in this groove 18
19 is fitted, and after inserting the sliding pad 19 into the stationary plate base metal 20, several notches 21 are provided on the edge so that it can be easily taken out or replaced for inspection as shown by the arrow in the figure.

The sliding pad 19 is made of tetrafluoroethylene material filled with glass fiber, molybdenum disulfide, etc., and has a thickness such that the sliding pad 19 is not displaced or caught due to high surface pressure or high peripheral speed. And, it is thicker than the groove depth of the stationary plate metal 20. Also, the sliding pad 19
Has been finished so that both sides can become sliding surfaces, and even if the sliding surface is damaged, it can be used inside out.

As a modification of this embodiment, the means shown in FIGS. 4 and 5 may be used. That is, FIG. 4 is a perspective view of a main part of the thrust bearing stationary plate. As shown by an arrow in the drawing, the stationary plate base 20 individually manufactured is provided with the groove 18 for fitting the sliding pad 19. It can be slid to greatly improve workability. Further, as shown in FIG. 5, which is a sectional view taken along the line BB in FIG. 4, a stopper 22 is provided so that the sliding pad 19 does not come off during operation of the rotating electric machine, and is fixed by a bolt 23. With such a structure, the same effect can be obtained.

[0022]

As described above, according to the thrust bearing device of the present invention, the bearing average surface pressure is significantly improved by the elastic support structure using the disc spring to which the initial load is applied.
Sound operation is possible even when using a large-capacity rotating electric machine that requires a high peripheral speed and a large load. Further, since the groove provided on the stationary plate base metal and the sliding pad fitted to the groove are provided, it is possible to promptly deal with damage to the thrust surface and rational operation of the rotating electric machine becomes possible.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a stationary plate of a thrust bearing device of the present invention.

FIG. 2 is a sectional view showing an embodiment of a stationary plate of the thrust bearing device of the present invention.

FIG. 3 is a perspective view of a main part showing an embodiment of a stationary plate of the thrust bearing device of the present invention.

FIG. 4 is a perspective view of a main part showing an embodiment of a stationary plate of the thrust bearing device of the present invention.

FIG. 5 is a sectional view of a stationary plate of the thrust bearing device taken along line BB.

FIG. 6 is a layout view of a conventional coil spring.

FIG. 7 is a deflection characteristic diagram.

[Explanation of symbols]

11 ... Belleville spring, 12 ... Seat plate, 13 ... Upper clamp, 14 ... Lower clamp, 15 ... Disc bolt, 16 ... Stationary plate, 17 ... Clasp, 18 ...
Grooves, 19 ... sliding pads, 20 ... stationary plate base metal, 21 ... notches,
22 ... Stopper, 23 ... Bolt.

Claims (3)

[Claims] 1. A thrust bearing device comprising a stationary plate for supporting a rotary shaft of a vertical rotating electric machine used in a water turbine power plant and an elastic body for elastically supporting the stationary plate, wherein a disc spring as the elastic body. And an upper clamp and a lower clamp that sandwich the disc spring to form the stationary plate, and an initial load is applied to the disc spring sandwiched between the upper clamp and the lower clamp, and the upper clamp and the lower clamp are fixed. A thrust bearing device comprising a countersunk bolt. 2. The thrust bearing device according to claim 1, wherein the upper clamp and the lower clamp are fixed by using a stopper plate instead of the countersunk bolt. 3. A sliding pad made of tetrafluoroethylene material filled with glass fiber or molybdenum disulfide, which is provided on the stationary plate side that receives axial surface pressure from the rotating shaft, and a sliding pad provided on the stationary plate. A thrust bearing device comprising a sliding pad and a groove portion that fits therein.