JPH11270550A - Thrust bearing, and manufacture of its bearing pad - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thrust bearing which is free from any damages of a sliding surface or any separation of a resin sliding member even when subjected to a large load, and the start and stop are repeated, capable of sufficiently demonstrating the lubrication characteristic of a resin materiel, and excellent in reliability. SOLUTION: In a manufacturing method for a thrust bearing pad 4 in which a resin sliding member is fixed to a surface on the sliding side of a back metal, a wedge-like groove 7 is provided on the surface on the sliding side of a back metal 6 in connecting the back metal 6 of the bearing pad 4 to a resin sliding member 5, the resin sliding member 5 is laminated in the groove through a sintered body 8, and this laminated body is heated, and pressurized and joined until the resin sliding member 5 is bitten into a projecting end of a groove wall of the wedge-like groove.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a thrust bearing device having a fan-shaped bearing pad radially arranged around a rotating body, such as a vertical turbine generator, and more particularly to a bearing. The present invention relates to a thrust bearing device in which a resin-based sliding member is used as a pad sliding member.

[0002]

2. Description of the Related Art In recent years, hydroelectric power generation facilities have tended to increase in capacity and speed as represented by pumped-storage generators in view of the location conditions of power plants and costs. The thrust bearing device used for the vertical shaft turbine generator supports not only the weight of the rotating body of the turbine and the generator but also the water thrust applied to the turbine. For large capacity machines, the thrust bearing is 300
It will support a load of 0 to 4000 tons, and its peripheral speed will reach as high as 40 to 50 m / sec, and the bearing loss tends to increase further.

In pumped storage generators, water used for daytime power generation and stored in a lower pond is pumped to an upper pond at night so that the pump is always started and stopped on a daily basis, and operating conditions are severe. It has become something. For this reason, a thrust bearing device in the future is required to have a high reliability so as to sufficiently cope with all operating conditions and to supply power stably for a long period of time.

By the way, as a sliding material for these bearing pads, tin-based white metal has been used for many years. However, since the melting point of white metal is around 240 ° C and the high-temperature fatigue strength is low, for example, in bearings of models that repeatedly start and stop at high speed and high load, such as pumped generators, the sliding surface Since the operation is performed in a state where the oil film is not sufficiently formed, if used for a long period of time, the sliding surface may be damaged due to low cycle fatigue or the like, and eventually the bearing may be burnt.

On the other hand, recently, engineering plastic materials having low friction and heat resistance have attracted attention as sliding materials. In particular, thermoplastic resin polytetrafluoroethylene (hereinafter referred to as PTFE) has been used as a sliding member for bearings of large rotating machines. ), Polyether ether ketone (hereinafter, referred to as PEEK), and glass fiber, carbon fiber, molybdenum disulfide, etc. added to these to improve mechanical strength, sliding characteristics, wear resistance, etc. Molecular composite resin materials have begun to be used in thrust bearings of turbine generators.

When such a resin is used for a thrust bearing of a large-sized rotating machine, a high load is imposed on the thrust bearing, so that a resin material is always integrally bonded to a high-rigidity steel back plate (strength member). ing. Therefore, if the adhesion strength between the two members is insufficient, the resin sliding portion peels off during operation, which may cause a fatal accident. Therefore, the joining technique between the resin material and the strength member is an essential issue. I have.

[0007] Regarding the method of bonding this resin material to the strength member, Japanese Patent Application Laid-Open Nos. 59-2839 and 59-1
JP-A-82843 and JP-A-63-297457 disclose a method of forming a porous layer on a metal backing metal, impregnating and covering the surface with a PEEK composite composition, and forming a sliding member. .

In Japanese Unexamined Patent Publication No. Hei 5-296235, a wire member such as a wire mesh or a coil bobbin made of copper or a copper alloy material is joined to the upper surface of an iron-based base metal by silver brazing or the like. Tetrafluoroethylene (P
TFE) materials are melted at high temperature, filled and pressurized.
A method of integrally joining a TFE material and an iron base is disclosed.

[0009]

According to such a manufacturing method, for example, in the former method, carbon fiber, PT
A composition composed of a mixture of FE, bronze, graphite, etc. and PEEK is formed by impregnating the uneven surface of the porous layer with pressure to improve the bonding strength by the anchor effect. When applied to the sliding material of the thrust bearing of a rotating machine, the thrust bearing can be used under the operating conditions in which starting and stopping are frequently repeated at high speed and high load.
The sliding surface is operated in a state where an oil film is not sufficiently formed, so it undergoes load deformation and thermal deformation, and the resin material and the strength member have different coefficients of thermal expansion. When used for a long period of time, the joint surface may be deteriorated, and a trouble such as damage to the sliding surface or peeling of the resin sliding member from the strength member may occur.

In the latter method, PTFE is melted at a high temperature and bonded to the space of the linear member fixed to the base metal with a silver solder, so that sufficient adhesion strength can be obtained. Since both the PTFE and the linear member are elastic, there is a possibility that deformation such as distortion may occur when supporting a large load, and it is necessary to carefully manufacture in consideration of this point.

SUMMARY OF THE INVENTION The present invention has been made in view of the foregoing, and it is an object of the present invention to provide a method in which a sliding surface is damaged and a resin sliding material is damaged even when a heavy load is applied and a start-stop operation is repeatedly performed. An object of the present invention is to provide a thrust bearing device of this kind which can sufficiently exhibit the lubricating properties of a resin material without causing peeling and has high reliability.

[0012]

That is, the present invention relates to a method of manufacturing a thrust bearing pad in which a resin-based sliding member is fixed to a sliding-side surface of a backing metal. At the time of coupling with the moving member, a wedge-shaped groove is provided on the sliding-side surface of the back metal, and a resin-based sliding material is laminated in this groove via a sintered body. The sliding member is pressurized and joined until it penetrates into the groove wall protruding end of the wedge-shaped groove to achieve the intended purpose.

In a method for manufacturing a thrust bearing pad in which a resin-based sliding member is fixed to a sliding-side surface of a backing metal, when the backing metal of the bearing pad and the resin-based sliding member are connected to each other, A wedge-shaped groove is provided on the sliding-side surface of the back metal, and a resin-based sliding member is laminated in this groove via a sintered body. The resin-based sliding material is melted and flown into the space, and is pressed and joined until the resin-based sliding material bites into the groove wall protruding end of the wedge-shaped groove.

In this case, the wedge-shaped groove extends in a direction perpendicular to the sliding direction of the sliding member and is formed over the entire length of the back metal, and the sliding surface of the resin-based sliding member is formed on the back metal. The projection is formed to be higher than the end face, and the height of the projection is formed smaller than the depth of the resin-based sliding member located in the wedge-shaped groove.

Further, the bearing pad includes a plurality of bearing pads arranged at predetermined intervals around the rotation shaft, and a lubricating tank containing the bearing pads. In the thrust bearing device, the sliding member of the bearing pad is heated and pressed through a sintered body into a wedge-shaped groove provided on the sliding-side surface of the backing metal, and the groove wall protruding end of the wedge-shaped groove is formed. It is formed so as to be bitten into.

That is, according to the thrust bearing device and the manufacturing method formed as described above, a wedge-shaped groove is provided on the sliding-side surface of the back metal when the back metal is connected to the resin-based sliding member. The resin-based sliding material is laminated on the sintered body via a sintered body, and these are heated and pressed until the resin-based sliding material bites into the groove wall protruding end of the wedge-shaped groove. The system sliding member is melted and impregnated and welded to the pores of the sintered body, and the tip projections of the wedge-shaped grooves are solidified in such a manner as to bite into both side ends of the facing sliding member. Therefore, the resin-based sliding member is a strength member because the resin-based sliding member is joined and fixed by the anchor effect of the sintered body as the joining medium, and the side end of the sliding member is joined and held by the tip protrusion. The strength of the joint with the back metal can be improved.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. FIG. 1 shows the thrust bearing device and the thrust bearing pad. 1 is a rotating shaft of, for example, a water turbine generator, 14 is an oil tank,
4 is a thrust bearing pad.

The thrust bearing device calculates the total weight of the rotating body composed of the thrust collar 2 and the thrust runner 3 fixed to the rotary shaft 1 and the total weight of the water thrust applied to the water turbine by the lubricating oil in the oil tank 14. 16, supported by a plurality of radially arranged thrust bearing pads 4. The thrust bearing pad 4 is tiltably supported by a spherical pivot 17 and is positioned by a detent 13.

An oil dam 15 is provided at the innermost periphery of the oil tank 14 to store the lubricating oil 16 and prevent oil leakage to the outside. A cooling device (not shown) for cooling the lubricating oil 16 is disposed outside the oil tank 14 so as to circulate and cool through a pump (not shown) and a supply / discharge oil pipe (not shown). It is configured.

FIG. 1B shows PEEK as a sliding material.
FIG. 3 is a perspective view of a thrust bearing pad 4 to which a system resin is applied.
Groove 7, sinter 8 and PE formed at one end of
It is composed of an EK resin-based sliding member 5 and the like.

Normally, since the thrust bearing pad is formed in a sector shape, the sintered body 8 is formed at one end of the back metal 6 as shown in FIG. ) Is inserted from one end of the wedge-shaped groove 7 penetrated as shown by an arrow, and is fixed to the back metal 6 by a diffusion bonding method or by heat fusion through an insert material having a lower melting point than the material of the sintered body 8. Is done.

Next, the PEEK-based sliding member 5 is laminated on the sintered body 8 and joined to the back metal 6 by applying heat and pressure. At this time, the temperature is lower than the melting point of the material of the sintered body 8 and the PEEK is used. The temperature is set within a temperature range higher than the melting point of the resin, and the load is set to an appropriate value in consideration of the thickness of the PEEK-based sliding member 5 and the porosity of the sintered body 8.

The PEEK-based resin sliding material 5 on the sintered body 8 is melted under such heating and pressurizing conditions, and is impregnated into the pores 9 of the sintered body 8 and fusion-bonded. Further, as shown in FIG. 3, the tip projections 11 of the wedge-shaped grooves 7 are solidified while being cut into the opposite side ends of the opposing PEEK-based resin sliding member 5. Therefore, the PEEK-based resin sliding material 5 is joined and fixed by the anchor effect of the sintered body 8 as the joining medium, and the side ends are joined and held by the tip projections 11, so that the back metal 6 as the strength member The rigidity of the thrust bearing pad 4 can be configured by improving the strength of the joint.

FIGS. 4A and 4B show the joined state of the thrust bearing pads 4 in another embodiment of the present invention, in which (a) before the sintered body is joined, (b) the setting of the PEEK-based sliding material, and (c) the completed state. FIG.

At the time of joining the sintered body 8, first, the state shown in FIG.
A low-melting-point insert material is inserted between the metal and the backing metal 6, and are fused by heating. As the insert material, any of a plate and a powder can be used. However, when the insert material is made as thin as possible, the variation in the joining strength is reduced and the joining accuracy can be improved.

Next, the PEEK-based sliding member 5 is laminated on the sintered body 8, and the PEEK-based sliding member 5
The width L1 is set to L1 ≦ L2 with respect to the width L2 of the wedge-shaped groove 7, and the state shown in FIG. The sintered body 8 is formed by forming only bronze-based spherical particles having a uniform size by fusing, and the porosity is uniformly regulated.
It facilitates the impregnation of EEK resin.

(C) shows the state after joining, in which the sliding surface of the PEEK resin-based sliding member 5 protrudes from the upper end surface of the back metal 6, and the protruding height dimension: t1 is located in the wedge-shaped groove 7. The thrust bearing pad 4 is configured such that t1 <t2 with respect to the dimension in the depth direction: t2. Since the PEEK resin has excellent wear resistance and hardly wears out, the protrusion height dimension: t1 is made as small as possible, and the depth dimension t2 located in the wedge-shaped groove 7 is made large to increase the wedge surface. The retaining and effective holding force are effective.

The PEEK on the sintered body 8 is heated and pressed.
The resin 5 is melted and impregnated in the pores 9 of the sintered body 8.
However, the coarser the pores 9 are, the easier the impregnation becomes. However, if the pores 9 are too coarse, the mechanical strength of the sintered body 8 decreases.
It is necessary to select the particle diameter in consideration of this point. Tests have confirmed that the impregnation can be sufficiently impregnated if the roughness of the pores 9 is controlled within the range of 40 to 200 μm.

Although the depth of the impregnated resin 10 depends on the viscosity and load of the molten resin, the depth of the sintered body 8 is not necessarily limited.
It is not necessary to completely fill the pores 9 of the above, and if the pores 9 are impregnated by several hundred microns or more, a sufficient anchor effect can be obtained and the joining strength can be increased.

Further, even if the resin is melted, it does not overflow due to its high viscosity, and flows into the space 12 of the wedge-shaped groove 7 to be filled. The wedge-shaped groove 7 is opened in the radial direction, and air bubbles mixed therein are also discharged from both ends, so that the space 12 is completely buried with the resin and solidified. For this reason, the PEEK-based sliding member 5 is a sintered body 8 as a joining medium.
And the PEEK resin flows into the space 12 and solidifies following the wedge-shaped side wall, so that it is mechanically connected and held by the wedge surface. Can improve the joining strength.

In each of the embodiments described above, the resin material forming the sliding surface of the thrust bearing pad 4 is a resin material to which carbon fiber, graphite, bronze, glass fiber, a fluorine compound or the like is appropriately added according to the purpose. Since it is a plastic composition, it has excellent wear resistance and a small friction coefficient as compared with white metal, so that a stable fluid lubricating action can be obtained even under a high surface pressure. In addition, even when the oil film thickness in the operating state at the time of starting / stopping is extremely small, a good lubricating state can be maintained without causing surface roughness or wear. Due to the self-lubricating effect peculiar to the resin material, the supply of static pressure oil to the sliding surface by a high-pressure oil pump (oil lifter device), which has been indispensable at the time of starting and stopping, has become unnecessary. Simplification and maintenance and management become easier.

Further, the melting point of white metal is about 240
° C, while about 100 ° C for PEEK resin.
℃ and excellent in high temperature fatigue strength. Even if the sliding surface is operated for a long time in a state where an oil film is not sufficiently formed, the sliding surface is not damaged.

On the other hand, the end of the thrust bearing pad 4 is supported by a pivot 15 and is capable of tilting in the circumferential direction and the radial direction. It can be supported without contact. However, during rotation, the sliding surface generates heat due to the shear frictional action of the lubricating oil 14, causing a temperature difference in the thickness direction of the bearing pad 4, and this temperature difference causes the bearing pad 4 to deform in a convex shape. This deformation occurs in both the circumferential direction and the radial direction. In particular, the amount of deformation in the radial direction reduces the region where the oil film pressure is generated, so that the load resistance is greatly reduced.

However, since the thermal conductivity of the resin material is smaller than 1/200 or less than that of the white metal, the heat insulating effect on the back metal 6 acts greatly, and the thrust bearing pad 4
Thermal deformation can be minimized. Therefore, since the amount of deformation can be suppressed to a small value, an appropriate oil film pressure distribution is formed on the sliding surface of the bearing pad 4 and the load resistance is not impaired.

As described above, in the thrust bearing device formed as described above, a wedge-shaped groove is formed at one end of a backing metal which is a strength member constituting a thrust bearing pad, and a wedge-shaped groove is formed inside the groove as a joining medium. A resin-based sliding member is laminated and provided with a sintered body interposed therebetween, and first joining means for fusion-bonding these members by heating and pressing, and a wedge-shaped groove at a side end of the resin-based sliding member. By joining and holding, the resin-based sliding member is integrally joined to the strength member by combining with the second joining means that is mechanically joined to increase the joining strength, thereby preventing damage and peeling of the sliding surface. In addition, it is possible to obtain a highly reliable thrust bearing device for a vertical shaft type turbine generator that can sufficiently exhibit the lubrication characteristics of the resin material.

[0036]

As described above, according to the present invention, even if a heavy load is applied and the start / stop operation is repeated, the sliding surface is damaged and the resin sliding material is separated. Thus, the lubrication characteristics of the resin material can be sufficiently exerted, and a highly reliable thrust bearing device of this type can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view and a perspective view of a bearing pad showing an embodiment of a thrust bearing device of the present invention.

FIG. 2 is a perspective view of a back metal constituting a thrust bearing pad.

FIG. 3 is a cross-sectional view showing a state of joining bearing pads.

FIG. 4 is a cross-sectional view showing one embodiment of a method for manufacturing a thrust bearing pad of the present invention.

[Explanation of symbols]

1 ... rotating shaft, 2 ... thrust collar, 3 ... thrust runner,
4 ... Thrust bearing pad, 5 ... PEEK resin sliding material, 6
... back metal, 7 ... wedge-shaped groove, 8 ... sintered body, 9 ... pore part, 10
... impregnated resin layer, 11 ... tip protrusion, 12 ... space,
13: Non-rotating, 14: Oil tank, 15: Oil dam, 16: Lubricating oil, 17: Pivot.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H02K 19/16 H02K 19/16 A

Claims (5)

[Claims] 1. A method for manufacturing a thrust bearing pad in which a resin-based sliding member is fixed to a sliding-side surface of a backing metal, wherein when the backing metal of the bearing pad and the resin-based sliding member are joined to each other, A wedge-shaped groove is provided on the sliding-side surface of the back metal, and a resin-based sliding material is laminated in this groove via a sintered body, and these are heated. A method for manufacturing a thrust bearing pad, characterized in that the thrust bearing pad is joined by pressurizing it until it bites into a tip. 2. A method for manufacturing a thrust bearing pad in which a resin-based sliding member is fixed to a sliding-side surface of a backing metal, wherein when the backing metal of the bearing pad and the resin-based sliding member are joined to each other, A wedge-shaped groove is provided on the sliding-side surface of the back metal, and a resin-based sliding member is laminated in this groove via a sintered body. A method for manufacturing a thrust bearing pad, characterized in that the thrust bearing pad is melted and flown into a space portion, and is pressed and joined until the resin-based sliding material bites into a groove wall protruding end of the wedge-shaped groove. 3. The wedge-shaped groove extends in a direction perpendicular to the sliding direction of the sliding member and is formed over the entire length of the back metal, and the sliding surface of the resin-based sliding member is located above the upper surface of the back metal. 3. The thrust bearing pad according to claim 1, wherein the protrusion is formed to have a height smaller than a depth of a resin-based sliding member located in the wedge-shaped groove. Method. 4. A bearing system comprising: a plurality of bearing pads arranged at predetermined intervals around a rotation shaft; and a lubrication tank containing the bearing pads, wherein a sliding member of the bearing pads is a resin-based member. In the thrust bearing device, the sliding member of the bearing pad is heated and pressurized through a sintered body into a wedge-shaped groove provided on the sliding-side surface of the back metal, and the resin-based sliding material is formed. A thrust bearing device formed so as to bite into a groove wall protruding end of a wedge-shaped groove. 5. The wedge-shaped groove extends in a direction perpendicular to the sliding direction of the sliding member and is formed over the entire length of the back metal, and the sliding surface of the resin-based sliding member has an upper end surface of the back metal. 5. The thrust bearing device according to claim 4, wherein the thrust bearing device is formed so as to protrude further upward, and has a protruding height dimension smaller than a depth dimension of the resin-based sliding member located in the wedge-shaped groove.