JP3962103B2 - Thrust bearing - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thrust bearing, and is particularly useful when applied to a thrust bearing such as a turbine generator.
[0002]
[Prior art]
In order to cope with higher peripheral speeds and larger capacities of vertical shaft rotating electrical machines (vertical water turbine generators, etc.), the wear resistance of the bearing sliding surface is improved and the coefficient of friction is reduced to increase the average bearing surface pressure. Polytetrafluoroethylene (trade name: Teflon) is used as a material for forming the bearing sliding surface of the stationary plate (thrust pad) instead of a bearing material alloy mainly composed of metal such as tin in order to significantly reduce bearing loss. There has been proposed a thrust bearing having a stationary plate using a slab.
[0003]
A specific configuration of this conventional stationary plate will be described with reference to FIGS. 5 is a perspective view of a conventional stationary plate having a first configuration, FIG. 6 is a sectional view thereof, and FIG. 7 is a sectional view of a conventional stationary plate having a second configuration.
[0004]
As shown in FIGS. 5 and 6, the stationary plate 01A of the first configuration has a fan-shaped plane, is arranged radially around the rotation axis, and slidably supports the rotating portion (this The same applies to the stationary plate 01B described later). As shown in FIG. 6, the stationary plate 01A includes a sheet material 02 made of polytetrafluoroethylene that forms a bearing sliding surface, and an iron-based thrust pad base metal (hereinafter referred to as a “base”) on the lower side of the sheet material 02. 03) (which is referred to as “gold”). In this integral joining, the sheet material 02 and the base metal 03 are joined via, for example, a soft adhesive.
[0005]
The stationary plate 01B having the second configuration shown in FIG. 7 has a concave 03a having a reverse trapezoidal cross-sectional shape on the surface of the base metal 03, and the surface of the sheet material 02 is made of polytetrafluoro in powder form by a mold. Protruding portions 02a obtained by heating and pressurizing and baking ethylene are provided, and both are integrally formed.
[0006]
[Problems to be solved by the invention]
However, in the stationary plate of the thrust bearing according to the above-described prior art, a sheet material such as polytetrafluoroethylene is configured as a sliding surface. However, the adhesion between the sheet material 02 and the base metal 03 is not good. There are the following problems in joining to a metal base metal.
[0007]
The stationary plate 01A shown in FIGS. 5 and 6 is a method of bonding the sheet material 02 to the base metal 03 using an adhesive, but there is a problem in its bonding strength and its durability.
That is, the adhesive cannot avoid deterioration over time, and the durability of bonding decreases with time.
[0008]
In addition, the stationary plate 01B shown in FIG. 7 has good bonding strength and durability, but the manufacturing process is complicated, and thus requires a great deal of manufacturing cost.
That is, powdered polytetrafluoroethylene is melted at high temperature using a mold and fired to form a trapezoidal convex portion 03a, and then bonded to the base metal 03. Requires a lot of man-hours.
[0009]
In addition, since a mold is used, it is necessary to prepare a mold for each base metal having a different shape, which requires a lot of cost. Furthermore, the pressurization requires about 350 kgf / cm ² . Therefore, when the size of the base metal is increased, a considerably large press molding machine is required, and an additional investment of equipment is required, and further, the cost required for manufacturing increases.
[0010]
In view of the above-mentioned problems of the prior art, the present invention can easily join a plate (polytetrafluoroethylene molded plate or the like) that forms a bearing sliding surface to a base metal, and has a high joining strength. It is an object of the present invention to provide a thrust bearing having a stationary plate that can be kept for a long time and is inexpensive.
[0013]
[Means for Solving the Problems]
A first invention that solves the above-described problem is a thrust bearing including a stationary plate that slidably supports the rotating portion, wherein the stationary plate forms a bearing sliding surface that is in sliding contact with the rotating portion and is thick. A sheet material in which a concave portion having an inverted trapezoidal cross-sectional shape is formed in the vertical direction, a base metal in which a concave portion having a trapezoidal cross-sectional shape is formed at a position facing the concave portion of the sheet material, and a space formed when these are opposed to each other within, it becomes heated filling the low melting point metal, characterized in that the low-melting-point metal is made by integrally bonding the base metal and the sheet material.
[0014]
Therefore, according to the present invention having the above-described configuration, a sheet material (for example, a sheet material made of polytetrafluoroethylene) that forms a bearing sliding surface is easily integrated and joined to the base metal by using a metal having a lower melting temperature. In addition, since the bonding is performed with metal, the bonding strength between the sheet material and the base metal can be maintained for a long time.
[0015]
Further, in the above invention, when integrated with the sheet material and the base metal, and characterized by being bonded using adhesives.
[0016]
In the invention described above, the sheet material is a fluororesin-based molded plate such as polytetrafluoroethylene.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0018]
FIG. 1 is a sectional view showing the configuration of a stationary plate of a thrust bearing according to the first embodiment of the present invention, FIG. 2 is a sectional view of the stationary plate of the thrust bearing according to the second embodiment, and FIG. FIG. 4 is a sectional view of a base plate of a thrust bearing according to the embodiment, and FIG. 4 is a sectional view of a stationary plate of the thrust bearing according to the fourth embodiment.
[0019]
(First embodiment)
As shown in FIG. 1, the stationary plate 11 </ b> A according to the first embodiment has a fan-shaped flat surface as in the prior art and is arranged radially around the rotation axis to support the slidable portion in a slidable manner. (This also applies to stationary plates 11B and 11D described later).
[0020]
Then, as shown in FIG. 1, the stationary plate 11A is formed by fitting means formed by processing the sheet material 12A and the iron base metal 13A that form a bearing sliding surface that is in sliding contact with the rotating portion, respectively. They are integrally joined. Here, the sheet material 12A is a sheet-like plate formed by molding polytetrafluoroethylene which is a kind of fluororesin.
[0021]
In this sheet material 12A, a trapezoidal convex portion 12a having an inverted trapezoidal cross-sectional shape in the thickness direction is formed by processing, and one base metal 13A has a cross-sectional shape at a position facing the trapezoidal convex portion 12a. A trapezoidal trapezoidal concave portion 13a is formed, and the sheet material 12A and the base metal 13A are integrally joined by fitting them together. Therefore, the anchor effect is given by fitting the trapezoidal convex portion 12a and the trapezoidal concave portion 13a.
[0022]
The stationary plate 11A is manufactured as follows.
[0023]
{Circle around (1)} A trapezoidal convex portion 12a having a plurality of inverted trapezoidal cross-sectional shapes is formed on a sheet material made of polytetrafluoroethylene by machining to obtain a sheet material 12A shown in FIG.
(2) Next, a trapezoidal concave portion 13a having a trapezoidal cross-sectional shape for fitting the trapezoidal convex portion 12a is formed on the surface of the base metal 13A.
Note that the trapezoidal convex portion 12a and the trapezoidal concave portion 13a may be of inverted frustoconical shape, rectangular shape, or formed in the axial direction.
[0024]
(3) The sheet material 12A and the base metal 13A are bonded and integrated together with the fitting by using an adhesive on the joint surface when the convex portion 12a and the concave portion 13a are fitted.
[0025]
(Second Embodiment)
The stationary plate 11B shown in FIG. 2 is obtained by reversing the formation of the unevenness with the stationary plate 11A of the first embodiment shown in FIG.
In FIG. 2, the sheet material 12B has a trapezoidal concave portion 12b having a reverse trapezoidal cross-sectional shape in the thickness direction by processing, and one base metal 13B is at a position facing the trapezoidal concave portion 12b. A trapezoidal convex portion 13b having a reverse trapezoidal cross-sectional shape is formed, and the sheet material 12B and the base metal 13B are integrally joined by fitting them together. At this time, the anchor effect is provided by fitting the trapezoidal concave portion 12b and the trapezoidal convex portion 13b as in the first embodiment.
[0026]
(Third embodiment)
FIG. 3 shows another embodiment of the base 13B of the stationary plate 11B shown in FIG.
[0027]
As shown in FIG. 3, the trapezoidal convex portion 13c is integrally formed on the surface of the base metal 13C by a spot welding method or the like.
[0028]
Accordingly, the sheet material 12B shown in FIG. 2 and the base metal 13C shown in FIG. 3 are fitted into the recess 12b of the sheet material 12B with the trapezoidal member 13c having the inverted trapezoidal cross-sectional shape formed by spot welding. At the time of joining, an adhesive is used for the joint surfaces to bond and integrate.
[0029]
(Fourth embodiment)
As shown in FIG. 4, the stationary plate 11 </ b> D shown in FIG. 4 is formed by integrally joining a sheet material 12 </ b> D that forms a bearing sliding surface that is in sliding contact with a rotating portion to an iron base 13 </ b> D using a low melting point metal 14. It will be. Here, the sheet material 12D is a sheet-like plate formed by molding polytetrafluoroethylene which is a kind of fluororesin.
[0030]
In this sheet material 12D, a trapezoidal recess 12b having a plurality of inverted trapezoidal cross-sectional shapes in the thickness direction is formed by processing, and the cross-sectional shape of one base metal 13A is trapezoidal at a position facing the trapezoidal recess 12b. The trapezoidal recess 13a is formed. Then, the low melting point metal 14 is heated and filled in the space formed when the two faces each other, and is cooled and solidified. Therefore, the anchor effect is given by the low melting point metal 14 filled and solidified in the space.
[0031]
Such a stationary plate 11D is manufactured as follows.
[0032]
(1) A sheet material 12D shown in FIG. 4 is formed by forming a plurality of inverted trapezoidal trapezoidal concave portions 12b in a polytetrafluoroethylene sheet material by processing.
(2) Next, a trapezoidal recess 13a is formed on the surface of the base metal at a position corresponding to the trapezoidal recess 12b to obtain a sheet material 13D shown in FIG.
[0033]
{Circle around (3)} The sheet material 12D and the base metal 13D are joined to form a space by the recess 12b and the recess 13a. An adhesive is used for this joining.
[0034]
(4) Next, the space is heated and filled with a low-melting point metal such as white metal, cooled to solidify the low-melting point metal, and the two are integrally joined through the low-melting point metal 14. It will be.
[0035]
From the above, according to the stationary plates 11A, 11B, and 11D configured as described above, the following effects can be obtained.
[0036]
(1) The sheet material and the base metal can be integrally joined at a relatively low cost without using a separate large-scale facility using a special die as in the prior art. Manufacturing cost can be reduced.
[0037]
(2) Also, as shown in FIGS. 1 to 3, the sheet material and the base metal are joined by processing the sheet material or the base metal instead of the conventional soft adhesive, so that the uneven portion is formed. The thrust bearing is merely formed and does not decrease due to aging or thermal deterioration, and an extremely reliable thrust bearing can be configured.
[0038]
(3) Further, as in the stationary plate 11D as shown in FIG. 4, a low melting point is formed in the space formed when the sheet material 12D having the recess 12b and the base metal 13D having the recess 13a are joined. The process can be simplified and the cost can be reduced by heating and filling the metal to solidify and integrating the two.
[0039]
【The invention's effect】
As described above in detail with the embodiment of the invention, according to the present invention, a conventional unique mold is formed, and powdered polytetrafluoroethylene is melted at high temperature and fired. It is possible to manufacture a thrust bearing at low cost without the need for joining with a base metal.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of a stationary plate of a thrust bearing according to a first embodiment of the present invention.
FIG. 2 is a sectional view of a stationary plate of a thrust bearing according to a second embodiment.
FIG. 3 is a sectional view of a base of a thrust bearing according to a third embodiment.
FIG. 4 is a cross-sectional view of a stationary plate of a thrust bearing according to a fourth embodiment.
FIG. 5 is a perspective view of a stationary plate having a first conventional configuration.
6 is a cross-sectional view of FIG.
FIG. 7 is a perspective view of a stationary plate having a conventional second configuration.
[Explanation of symbols]
11A, 11B, 11D Stationary plates 12A, 12B, 12D Sheet material 12a Trapezoidal convex part 12b Trapezoidal concave part 13a Trapezoidal concave part 13b Trapezoidal convex part 13c Trapezoidal members 13A, 13B, 13C, 13D Base metal 14 Low melting point metal

Claims (3)

A thrust bearing provided with a stationary plate that slidably supports the rotating part,
The stationary plate forms a bearing sliding surface that is in sliding contact with the rotating portion and has a recessed portion having a trapezoidal cross-sectional shape in the thickness direction, and a trapezoidal cross-sectional shape at a position facing the recessed portion of the sheet material. A base metal in which a concave portion is formed and a space formed when these are opposed to each other are heat-filled with a low melting point metal, and the sheet material and the base metal are integrally joined by the low melting point metal. Thrust bearings characterized by being made. A thrust bearing for the thrust bearing of claim 1, when integrated with the sheet material and the base metal, characterized by being bonded using adhesives.  3. The thrust bearing according to claim 1, wherein the sheet material is a polytetrafluoroethylene fluororesin-based molded plate.

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