JP5828387B2 - Bearing for molten metal plating bath - Google Patents

Description

  The present invention has an automatic alignment function that is immersed in a molten metal plating bath to rotatably support a support roll and a sink roll in a molten metal plating apparatus for plating molten zinc, molten aluminum and other molten metals on the surface of a steel sheet. It is an invention related to a bearing for a molten metal plating bath.

  FIG. 5 shows a schematic configuration diagram of a molten metal plating apparatus in which a bearing for a molten metal plating bath related to the above technical field (hereinafter sometimes simply referred to as a bearing) is incorporated. As shown in FIG. 5, a molten metal plating apparatus 20 is immersed in a plating tank 22 in which a molten metal plating bath (hereinafter, simply referred to as “plating bath”) 21 is stored, and a surface layer portion of the plating bath 21. Then, a snout 23 for preventing oxidation of the steel sheet W introduced into the plating bath 21, a sink roll 28 disposed in the plating bath 21, and the sink roll 28 in the plating bath 21 above the sink roll 28. And a gas wiping nozzle 26 positioned slightly above the surface of the plating bath 21. No external driving force is applied to the sink roll 28 itself, and the sink roll 28 is driven counterclockwise by a frictional force caused by contact with the traveling steel plate W. The support roll 27 is usually a drive roll connected to an external motor (not shown). The support roll 27 may be a non-driving type in which no external driving force is applied. A sink roll 28 and a pair of support rolls 27, which are rolls for a molten metal plating bath, are rotatably supported by bearing devices 1 and 1 attached to the frames 24 and 25, respectively, and are always integrated into the plating bath 21 as a unit. Soaked.

  The steel plate W enters the plating bath 21 from the oblique direction through the snout 23, and the traveling direction can be changed upward via the sink roll 28. The steel plate W rising in the plating bath 21 is sandwiched between a pair of support rolls 27 that press the steel plate W with a constant force, so that the pass line is maintained and warpage and vibration are prevented. The gas wiping nozzle 26 sprays high-speed gas onto the steel sheet W coming out of the plating bath 21 and uniformly adjusts the thickness of the molten metal plating attached to the steel sheet W by the gas pressure of the high-speed gas. In this way, a steel plate W on which molten metal plating has been applied can be obtained. Here, each support roll 27 is subjected to a force directed toward the upper right direction or the upper left direction as indicated by an arrow D from the pressing force against the steel plate W, and the bearing device that supports the sink roll 27. 1 will load the force which goes in the diagonally upward direction. Further, the sink roll 28 is subjected to a force directed obliquely upward to the left as indicated by an arrow G due to the tension applied to the steel plate W, and the bearing device 1 that supports the sink roll 28 has A force in the direction is loaded.

  Here, a support roll 27 and a sink roll 28 (hereinafter collectively referred to as rolls 27 and 28), which are rotating bodies immersed in a molten metal plating bath (hereinafter may be simply referred to as a plating bath) 21, respectively. In the shaft part) is deformed due to thermal deformation by the high-temperature plating bath 21 or due to a load applied from the steel plate W. When the shaft portion is bent and eccentric due to the deformation, uneven wear occurs on the inner surface of the bearing that supports the shaft portion, and the rolls 27 and 28 exhibit phenomena such as rotation failure and vibration. Such a phenomenon has caused a problem related to quality that scuffs and creases are generated on the surface of the plated steel sheet and a problem related to productivity that the traveling speed of the steel sheet cannot be increased.

  In order to solve such a problem, a bearing having an automatic alignment function has been proposed, and an example thereof is disclosed in Patent Documents 1 and 2 below. Patent Document 1 states that “in the support roll in the molten metal bath in the molten metal plating line, the support roll is undriven, and self-fluxing alloy spraying is performed on the outer periphery of the sleeve that is in sliding contact with the support roll bearing. There is disclosed a support roll in a non-driven molten metal bath, characterized in that a bush whose cross-sectional shape is mirror-finished on the surface is provided, and the outer periphery of the bush is a spherical bearing. '' Functions as a self-aligning bearing.

  Further, the bearing device disclosed in Patent Document 2 is “a bearing device that rotatably supports a roll immersed in a hot dipping bath, and is a bearing that is built in a housing and supports the axial load direction of the roll. A bearing device having a centering function in which an outer peripheral portion of a member is formed so that each of a front view and a side view has an arc shape.

JP 2005-248298 A Japanese Utility Model Publication No. 1-119048

  The bearings disclosed in Patent Documents 1 and 2 can solve the problems associated with the eccentricity of the rolls by the automatic alignment function, but have the following problems. That is, the bush which is a bearing in the support roll of Patent Document 1 has a spherical outer peripheral surface having an automatic alignment function, and the inner surface is a sliding surface that slides with the shaft portion of the support roll. . Here, since the bearing for the molten metal plating bath is used in a plating bath having high corrosiveness, in addition to frictional wear due to sliding, corrosion wear due to the plating bath is likely to proceed, and the sliding surface is greatly worn during use. Roughen. When the sliding surface becomes rough, the coefficient of friction with the surface of the shaft portion increases, so that a phenomenon called so-called rotation occurs, in which the bearing rotates as the shaft portion rotates. Due to the rotation of the shaft portion, the outer peripheral surface of the bearing or the inner surface of the arm with which the outer peripheral surface comes into contact is worn, and there is a problem that the automatic alignment function that the bearing should perform is impaired. In particular, in a ceramic bearing, which is a difficult-to-process material, it is very difficult to form the outer peripheral surface in a spherical shape as in the bearing of Patent Document 1, and the cost of the bearing increases in industrial production. There was a problem.

  On the other hand, according to the bearing disclosed in Patent Document 2, the rotation stop is arranged so that the front view contacts the bottom surface of the semi-circular bearing, thereby avoiding the accompanying rotation of Patent Document 1. The occurrence of wear on the outer peripheral surface of the bearing due to rotation can be prevented. However, in the bearing of Patent Document 2, for the eccentricity of the shaft portion, both the alignment of the vertical component and the horizontal component are borne only by the top portion of the outer peripheral surface of the bearing. For this reason, there is a problem in that the top of the outer peripheral surface of the bearing or the inner surface of the housing with which the top contacts is locally worn, which impairs the automatic alignment function that the bearing should perform. Moreover, the bearing of patent document 2 needs to form the outer peripheral surface of a bearing so that each of front view and side view may become circular arc shape, and, like the bearing of patent document 1, the cost of a bearing is industrially produced. There was a problem of becoming higher.

  The present invention has been made by the inventor's earnest examination of the above-mentioned problems of the prior art. In a bearing for a molten metal plating bath that is immersed and used in a molten metal plating bath, the surface of the surface that should have an automatic alignment function is provided. It is an object of the present invention to provide a bearing for a molten metal plating bath having a simple configuration that has little wear during use and can maintain an automatic alignment function for a long period of time.

  One aspect of the present invention that achieves the above object is a molten metal that rotatably supports a shaft portion of a rotating body immersed in a molten metal plating bath and is supported by a support member having two planes orthogonal to each other. A plating bath bearing, wherein the outer peripheral surface of the shaft portion is slidable while being in contact, and extends in the same direction as the direction in which the sliding surface extends, and two planes of the support member The bearing for a molten metal plating bath is characterized in that it has at least two surfaces facing each other, and a convex portion in contact with the flat surface facing each other and the top is formed on each of the two surfaces.

  The support member is replaced with the two planes and has four planes orthogonal to each other, and the molten metal plating bath bearing is replaced with the second plane and extends in the same direction as the direction in which the sliding surface extends. In addition, there may be four surfaces facing the four planes of the support member, and the four surfaces may be formed with convex portions that contact the support planes that face each other and the top.

  Furthermore, the plane of the support member may be formed on the bearing instead of the support member, and the surface of the bearing may be formed on the support member instead of the bearing.

  It is preferable that the support member has a support surface placed on one end side of the flat surface of the support member, and the molten metal plating bath bearing further has a convex portion whose top is in contact with the support surface.

  It is preferable that a gap is provided between the top of the convex portion formed on the surface of the bearing and the plane of the support member to which the surface of the bearing faces.

  It is preferable that an outer edge shape of the convex portion in a direction in which the sliding surface extends is an arc shape. It is more preferable that the convex portion whose outer edge shape is an arc shape is formed from one end to the other end of the surface of the bearing in the direction in which the sliding surface extends. Further, it is desirable that the convex portion whose outer edge shape is an arc shape is arranged such that the top portion thereof is deviated to one end side from the center of the surface of the bearing in the direction in which the sliding surface extends. .

  Furthermore, when the outer edge shape of the said convex-shaped part is circular arc shape, it is preferable that the connection surface which connects each is interposed between the adjacent surfaces among the surfaces of the said bearing. The shape of the connection surface is preferably an arc shape bulging outward in a cross-sectional view along a direction orthogonal to the direction in which the sliding surface extends.

  It is preferable that the support member is formed with a through-hole that communicates with the top of the convex portion whose outer edge shape is an arc shape.

  In the direction in which the sliding surface extends, it is preferable that an R surface or a C surface is formed at at least one corner of one end and the other end of the bearing surface.

  In the direction in which the sliding surface extends, it is preferable that an R surface or a C surface is formed at at least one corner of one end and the other end of the sliding surface.

  The sliding surface of the bearing is preferably made of ceramics.

  According to the present invention, the object of the present invention can be achieved as described in detail below.

It is a perspective view of the bearing apparatus with which the bearing of the 1st aspect concerning this invention was integrated. 2 is a cross-sectional view taken along a vertical plane A and a horizontal plane H with respect to the shaft core of the bearing of FIG. It is BB sectional drawing of FIG. FIG. 2 is a front view, a rear view, and a right side view of FIG. 1. It is a schematic block diagram of the molten metal plating apparatus with which the bearing apparatus of FIG. 1 was integrated. It is a figure of the bearing apparatus incorporating the bearing of the 1st modification of the bearing of FIG. 1, and a 2nd modification. It is a figure of the bearing apparatus with which the bearing of the 3rd modification of the bearing of FIG. 1-the 5th modification was integrated. It is a front view of the bearing apparatus with which the bearing of the 2nd aspect concerning this invention was integrated. It is a figure of the bearing apparatus with which the bearing of the 3rd aspect and 4th aspect concerning this invention was integrated. It is a sectional side view of the bearing apparatus with which the bearing of the 5th aspect concerning this invention was integrated.

  Hereinafter, the bearing according to the present invention will be specifically described with reference to the drawings based on the first aspect, a plurality of modifications of the first aspect, and the second to fifth aspects. The bearings of the first to fifth aspects are all incorporated in the bearing device and used by being incorporated in the molten metal plating apparatus described with reference to FIG. 5, but the present invention is not limited to this. Without departing from the above, the present invention can be appropriately modified and implemented within the range of identity as long as the effects are exhibited. Moreover, each component of the bearing of the 1st-5th aspect can be implemented in combination with each other suitably as long as there exists an effect of this invention. Further, in the following explanation, a bearing that rotatably supports the shaft portion of the support roll as a rotating body immersed in the plating bath will be described as an example. However, the present invention is immersed in a sink roll or other molten metal plating bath. The same can be applied to the rotating body to be used.

[First Embodiment]
The bearing of a 1st aspect is demonstrated with reference to FIGS. Here, FIG. 1 is a perspective view of the bearing device 1 in which the bearing 3 of the first aspect is incorporated, and FIG. 2 is along a plane A and a plane H perpendicular to the axis I of the bearing 3 in FIG. Cross-sectional view of the bearing device 1, FIG. 3 is a front cross-sectional view that is a BB cross-section of FIG. 2, FIG. 4 (a) is a front view of the bearing device of FIG. 1, and FIG. FIG. 4C is a side view thereof. 1 to 3, in the following description, the axis along the axis I of the bearing 3, which is the direction in which the sliding surface 3 a of the bearing 3 extends, is orthogonal to the X axis, the X axis, and the axis. The axis that intersects I horizontally is referred to as the Y axis, and the axis that intersects perpendicularly to the axis I perpendicular to both the X axis and the Y axis is referred to as the Z axis.

  As shown in FIG. 1, the bearing device 1 in which the bearing 3 of the first aspect is incorporated includes a bearing 3 that rotatably supports a shaft portion 27 a of a support roll that is a rotating body immersed in a plating bath, and the bearing. 3 and a support member 2 that supports 3. Hereinafter, the structure will be described in detail in the order of the support member 2 and the bearing 3. Although two sets of bearing devices 1 are arranged at both ends of the support roll, since the configuration of both is the same, only one bearing device 1 will be described, and description of the other bearing device 1 will be omitted.

[Support member]
As shown in detail in FIG. 3, the support member 2 according to the first aspect includes four planes orthogonal to each other (hereinafter referred to as support planes for easy understanding), specifically an upper support plane 2a and a lower plane. It has a support plane 2c, a right support plane 2d, and a left support plane 2b, and these four support planes 2a to 2d are the inner surfaces (one surface) of the flat plate members 2e to 2h, respectively. The four flat plate-like members 2e to 2h are storage chambers whose inner surfaces constituting the support planes 2a to 2d are orthogonal to each other, and each surface has a substantially rectangular cross section (in the case of this embodiment, a regular square shape). Each is fixed so as to form 2q. Further, although not essential in the present invention, as shown in FIG. 2, the support member 2 of this aspect includes a plane orthogonal to the support planes 2 a to 2 h at one end of the support planes 2 a to 2 h in the X-axis direction. Alternatively, the flat plate-like member 2i having the support surface 2m as an inner surface (one surface) is fixed to one end of the flat plate-like members 2e to 2h so that the arc-shaped support surface 2m is disposed. . And as shown in FIG. 1, the bearing 3 is accommodated in the storage chamber 2q from one end opening of the storage chamber 2q facing the flat plate member 2i in the X-axis direction, and its end portion is prevented from moving in the X-axis direction. Are fixed by a pair of fixing members 2n joined to the end faces of the flat members 2f and 2h.

  The flat members 2e to 2i are preferably made of a material having a corrosion resistance against a plating bath having a high chemical corrosion property, and a metal such as ceramics or stainless steel may be selected. Further, since the support planes 2a to 2d and the support surface 2m that are tilted while being in contact with the bearing 3 during automatic alignment are required to have wear resistance, when the flat members 2e to 2i are made of metal, It is desirable to form a film of ceramics or cermet having high hardness and excellent wear resistance on the support planes 2a to 2d and the support surface 2m.

  Furthermore, it is not necessary that the entire inner surface of the flat plate members 2e to 2i be the support planes 2a to 2d or the support surface 2m, and the support planes 2a to 2d or the support are in contact with the convex portions 3f and 3k of the bearing 3 to be described later. A surface 2m may be provided. In this respect, the support member 2 of the present embodiment, as a preferred embodiment, discharges the plating bath from the storage chamber 2q, which is a relatively sealed space, so that the discharge port of the plating bath connected to the storage chamber 2q is a flat plate member 2e. The central part which is a part of each inner surface (one surface) of the flat members 2e to 2i is the support planes 2a to 2d and the support surface 2m.

  Specifically, as shown in FIG. 1 and FIG. 4, the discharge port of the plating bath in the support member 2 of the present embodiment is formed by cutting the four corners of the flat plate members 2 e to 2 i, which are substantially ten-shaped. It is configured as four corner openings 2o and 2p. The plating bath that has entered the storage chamber 2q when the bearing device 1 is immersed in the plating bath is discharged from the openings 2o and 2p when the bearing device 1 is pulled up. According to the support member 2 having such a configuration, the plating bath that has entered the storage chamber 2q, particularly the gap between the support planes 2a to 2d thereof and the outer peripheral surface of the bearing 3, lifts the bearing device 1 for maintenance or the like. At this time, it easily flows out through the openings 2o and 2p. Therefore, after the bearing device 1 is pulled up, the plating bath remaining in the gap and cooled and solidified can be effectively prevented from being pressed against the bearing 3 by the support member 2 that contracts and deforms, and the bearing 3 is damaged. Become.

  In FIG. 1, reference numeral 2 </ b> L corresponds to the position of the top portion 3 g of the convex portion 3 f of the bearing 3, and is a through-hole-shaped plating bath outlet formed at substantially the center of the flat plate-like members 2 f and 2 h. is there. The operational effects of the discharge ports 2j and 2L will be described in detail in the description of the bearing 3 below.

  In the bearing device 1 of this embodiment, the discharge port of the plating bath is formed by cutting out the four corners of the flat plate members 2e to 2i as described above, but the discharge port may be continuous with the storage chamber 2q. You may comprise a discharge port in the shape of a through-hole. Further, from the viewpoint of smoothly discharging the plating bath from the storage chamber 2q, it is desirable that the plating bath does not easily adhere to the surfaces of the support planes 2a to 2d or the plating bath discharge ports 2o, 2p, 2j, and 2L. It is desirable to form a film such as a ceramic or cermet having low wettability with these. Furthermore, from the same viewpoint, it is desirable to provide the through-hole-like opening 2j at the center of the upper flat plate-like member 2e, and to configure the support member 2 so that the plating bath is smoothly discharged from the storage chamber 2q.

[bearing]
Next, the bearing 3 will be described. As shown in FIGS. 1 to 3, the bearing 3 of the first aspect includes a sliding surface 3 a extending in the X-axis direction, on which the outer peripheral surface of the shaft portion 27 a of the support roll having a substantially cylindrical shape slides, and a sliding surface. Four surfaces that extend in the X-axis direction, which is the same direction as the moving surface 3a extends, and respectively face the four support planes 2a to 2d of the support member 2 (hereinafter referred to as the outer surface for easy understanding). .) 3b-3e. As shown in FIG. 2, the four outer surfaces 3b to 3e are formed with convex portions 3f in contact with the support planes 2a to 2d that face each other and the top portion 3g.

  According to the bearing device 1 incorporating the bearing 3 having such a configuration, the outer peripheral surface of the shaft portion 27a of the support roll that rotates counterclockwise as shown by an arrow E in FIG. 3 is in contact with the sliding surface 3a of the bearing 3. Slide while. As shown in FIG. 3, since the load indicated by the arrow D acts on the support roll, the bearing 3 supports the shaft portion 27a at the upper left portion of the sliding surface 3a, and the outer surface 3b. 3e, the top 3g of the convex portion 3f provided on at least the upper outer surface 3b and the left outer surface 3c is in contact with the support planes 2a and 2b of the support member 2 facing them. Yes.

  When the shaft portion 27a is deformed by heating with a high-temperature plating bath or a load applied from the steel sheet and the shaft core is eccentric, the bearing 3 has a Y-axis and a Z-axis according to the eccentric amount of the shaft portion 27a. A rotational moment around the axis acts. Here, the top surfaces 3 g of the convex portions 3 f provided on the outer surfaces 3 b and 3 c of the bearing 3 are in contact with the support planes 2 a and 2 b of the support member 2. Thus, in the direction around the Y axis, the bearing 3 is eccentric with respect to the support plane 2a with the top 3g of the convex portion 3f provided on the outer surface 3b as a fulcrum because of the rotational moment around the Y axis. Tilt according to the amount. Further, in the direction around the Z axis, the bearing 3 has an eccentric amount with respect to the support plane 2b with the top 3g of the convex portion 3f provided on the outer surface 3c as a fulcrum because of the rotational moment around the Z axis. Tilt according to. Thus, of the rotational moment acting on the bearing 3 due to the eccentricity of the shaft portion 27a, the component around the Y-axis is the surface 3b of the convex portion 3f provided on the outer surface 3b, and the component around the Z-axis is the outer surface. The surface 3c of the convex portion 3f provided on 3c is separated and received by two surfaces and tilted in the respective directions, thereby suppressing the wear of the support planes 2a and 2b of the support member 2 due to the tilt of the bearing 3. However, automatic alignment of the bearing 3 according to the amount of eccentricity of the shaft portion 27a is possible. Furthermore, since the top 3g of the convex portion 3f formed on each of the outer surface 3b and the outer surface 3c is in contact with the support planes 2a and 2b orthogonal to each other, the outer peripheral surface of the shaft portion 27a and the sliding surface 3a of the bearing 3 are provided. The bearing 3 does not rotate around the axis I due to the frictional resistance when sliding.

  Next, an aspect of the bearing 3 as viewed from the front will be described with reference to FIG. As shown in the figure, the bearing 3 of this embodiment has a substantially rectangular cross section (in the case of this embodiment, a regular square shape), and the upper outer surface 3b is supported by the support plane 2a and the left outer surface 3c is supported. The flat surface 2b, the lower outer surface 3d is inserted into the storage chamber 2q of the support member 2 such that the lower outer surface 3d faces the support flat surface 2c and the right outer surface 3e faces the support flat surface 2d. A substantially cylindrical hollow portion 3s having an inner diameter larger than that of the shaft portion 27a is formed at the center of the bearing 3, and the inner peripheral surface of the hollow portion 3s functions as the sliding surface 3a. In addition, from the effect of the bearing of the first aspect described above, it is sufficient that the bearing 3 includes at least two outer surfaces 3b and 3c that are orthogonal to each other. However, if the direction of the load acting on the support roll fluctuates due to changes in operating conditions and the load may act in the direction opposite to the arrow D shown in FIG. 3, the load moves in the opposite direction. In order to support the supporting roll, it is preferable to have outer surfaces 3d and 3e facing the outer surfaces 3b and 3c.

  The outer surfaces 3b to 3e of the bearing 3 may be configured so that all of the outer surfaces 3b to 3e are in close contact with the support planes 2a to 2d. However, when the bearing 3 is inserted into the storage chamber 2q, as shown in the drawing, In addition, it is desirable that the gap a in the Z-axis direction or the gap b in the Y-axis direction be formed. By providing the gaps a and b in this way, the following advantages arise. First, it becomes easy to insert the bearing 3 into the storage chamber 2q. Secondly, the convex portions 3f of the two opposite outer surfaces, that is, the outer surfaces 3b and 3d and the outer surfaces 3c and 3e, have the same shape, and there is no need to arrange the top portion 3g at the same position in the X-axis direction. 3 can be formed at low cost, and the convex portions 3f can be formed in different shapes according to the eccentricity of the shaft portion 27a. When the outer surfaces 3b to 3e are all in close contact with the support planes 2a to 2d, the opposing outer surfaces 3b and 3d and the outer surfaces 3c and 3e are symmetrical with respect to the axis so that the bearing 3 exhibits an automatic alignment function. Therefore, it is necessary to make each convex part 3f have the same shape and to arrange the top part 3g at the same position in the X-axis direction. Thirdly, by providing the gaps a and b, the outer surfaces 3b and 3c are tilted with the support planes 2a and 2b for automatic alignment, and as a result, the bearing 3 is moved from the support member 2 even when the life is reached due to wear. Once it is removed, the bearing 3 is rotated 180 ° around the X axis and reinserted into the storage chamber 2q. The self-alignment can be made to function by the unused outer surfaces 3d and 3e. Life can be extended.

  Next, fourthly, since the plating bath that has entered between the outer surfaces 3b to 3e and the support planes 2a to 2d is discharged through the gaps a and b, the bearing 3 can be prevented from being damaged when the bearing device 1 is pulled up. In addition, since the top part 3g of each convex-shaped part 3f of the outer surfaces 3b-3e is comprised so that the support planes 2a-2d may be contacted, the plating bath which permeated the contact part of the top part 3g and the support planes 2a-2d is discharged | emitted. It may be difficult. In order to discharge the plating bath that has entered the contact portion, as described in the section of the support member 2, a through-hole shape corresponding to the position of the top portion 3g and formed at substantially the center of the flat plate-like members 2f and 2h. The plating bath discharge ports 2j to 2L are provided.

  Furthermore, as shown in FIG. 3, it is preferable that the bearing 3 is provided with joint surfaces 3o to 3r that connect each other between adjacent outer surfaces 3b to 3e. Specifically, in a cross-sectional view along the YZ plane orthogonal to the axis I, the outer surface 3b and the outer surface 3c are connected to each other at the connection surface 3o at the end portion, and the outer surface 3c and the outer surface 3d are connected to each other at the connection surface 3p. The same applies to the outer surface 3d and the outer surface 3e, and the outer surface 3e and the outer surface 3b. Here, even if the adjacent outer surfaces 3b to 3e are directly connected, the bearing 3 can exhibit the self-aligning function. However, when the outer surfaces 3b to 3e are directly connected, a sharp corner is formed in the connecting portion. Arise. Cracks and the like are likely to be caused at the corners due to the rapid heating and cooling when the bearing device 1 is immersed in the plating bath and when the bearing device 1 is pulled up. On the other hand, the damage of the bearing 3 can be suppressed by providing the connection surfaces 3o to 3r between the adjacent outer surfaces 3 as in the bearing 3 of this embodiment to eliminate the sharp corners. Further, by providing the connection surfaces 3o to 3r between the adjacent outer surfaces 3b to 3e, the plating bath that has entered between the bearing 3 and the support member 2 can be effectively discharged. The form of the connection surface is not particularly limited, and is a cross-sectional view orthogonal to the X axis, which is the direction in which the sliding surface 3a extends, that is, a straight C surface in the YZ plane, a concave surface retracted to the axis I side. In addition, a polygonal surface composed of a plurality of flat surfaces or curved surfaces and other various forms can be used. However, in order to reduce the sudden change portion of the thickness and reduce the thermal stress generated by heating / cooling, the shape of the connection surfaces 3o to 3r may be an arc shape bulging outward as shown in FIG. desirable.

  Next, the aspect which looked at the bearing 3 from the side surface is demonstrated with reference to FIG. As shown in FIG. 2, the bearing 3 of this aspect has a substantially U-shaped cross-sectional view along the X-axis in which the shaft portion 27 a is inserted from the opening at the left end of the hollow portion 3 s in the X-axis direction. The outer edge shape of the convex portion 3f formed on each of the outer surfaces 3b to 3e of the bearing 3 in a sectional view along the X-axis is an arc shape protruding outward. In the bearing 3 of this aspect, the convex part 3f whose outer edge forms an arc shape is formed across both ends so that the outer edge connects the left end (one end) to the right end (other end) of the outer surfaces 3b to 3e. The top 3g is located in the center in the axial direction. That is, in the bearing 3 of this aspect, the surface of the convex portion 3 f is substantially the outer surfaces 3 b to 3 e of the bearing 3. In addition, although the outer edge shape of each convex-shaped part 3f is the same, since the clearance gap a * b is provided between the bearing 3 and the supporting member 2 as demonstrated above, it is not necessary to make it completely the same. Different outer edge shapes may be used.

  In the bearing 3, the cross-sectional shape along the X axis of the convex portion 3 f is the same as the shape shown in FIG. 2 at any location on the Z axis and the Y axis. That is, the convex portion 3f has a substantially bowl shape as a whole, and the surface (also the outer surfaces 3b to 3e) of the convex portion 3f is a single curved surface protruding outward. Thus, by making the convex part 3f into a substantially bowl shape, the contact area with the support planes 2a to 2d of the support member 2 increases, and the convexity due to friction with the support planes 2a to 2d during the alignment operation. Since the wear of the surface of the shape portion 3f is suppressed and the life of the bearing 3 can be extended, it is preferable.

  Here, the bearing in which the shape of the convex part differs from the bearing 3 of the first aspect will be described with reference to FIGS. 6 and 7. 6 and 7 showing the bearing device 1 in which the bearings 4 to 8 according to the first to fifth modifications of the bearing 3 of the first mode differing only in the shape of the convex portion are shown in FIGS. The other constituent elements identical to those of the bearing 3 of the first mode are denoted by the same reference numerals, and detailed description thereof is omitted (second to fifth described below with reference to FIGS. 8 to 10). The same applies to the bearing of the embodiment.)

  FIG. 6A is a front view of the bearing device 1 in which the bearing 4 according to the first modification is incorporated. The bearing 4 of this aspect is formed in a hemispherical shape that extends in the X-axis direction and faces the support planes 2a to 2d and protrudes from the center of each of the outer surfaces 4b to 4e. It differs from the bearing 3 of a 1st aspect by the point which has 4f of convex parts. According to the bearing 4, since the top 3g of each hemispherical convex portion 4f is arranged so as to contact the support planes 2a to 2d of the support member 2, the top 3g corresponding to the eccentricity of the shaft portion 27a. The bearing 4 tilts as a fulcrum and performs an automatic alignment function while preventing rotation of the bearing 4 around the axis I. The bearing 4 has a hemispherical convex portion 4f, has a small contact area between the surface of the convex portion 4f and the support planes 2a to 2d, and is more wear resistant than the bearing 3 of the first mode. Although somewhat disadvantageous, the gap between the outer surfaces 4b to 4e and the support planes 2a to 2d is wide, which is advantageous from the viewpoint of the discharge performance of the plating bath.

  FIG. 6B shows a side sectional view of the bearing device 1 in which the bearing 5 according to the second modification is incorporated. In FIG. 6B, the right end portion of the bearing 5 is a side view. As shown in the figure, the bearing 5 of this embodiment is extended in the X-axis direction and has four planar outer surfaces facing the support planes 2a to 2d of the support member 2 (support planes 2b and 2d are not shown). 5b-5e (outer surface 5c is not shown) and a single convex portion 5f formed on each outer surface 5b-5e so as to project along the Z-axis or Y-axis. Is different. Such a bearing 5 can also exhibit an automatic alignment function while preventing rotation of the bearing 5 around the shaft core I, and further, with the support planes 2a to 2d as compared with the bearing 4 according to the first modification. Since the contact length is long, the wear resistance can be improved. It should be noted that, unlike the convex portion 5s formed on the outer surface 5e of the bearing 5, it is different from the other convex portions 5f in the X-axis direction so as to cope with the eccentricity of the shaft portion 27a which may occur in various forms. A convex portion may be provided at the position.

  FIG. 7A shows a side sectional view of the bearing device 1 in which the bearing 6 according to the third modification is incorporated. The bearing 6 of this embodiment is different from the bearing 3 of the first embodiment in that the cross-sectional shape along the X-axis has a substantially triangular convex portion 6f that protrudes outward. The cross-sectional shape along the X axis of the convex portion 6f is the same as the shape shown in FIG. 7A at any location on the Z axis and the Y axis, like the convex portion 3f of the first aspect. Yes, the convex portion 6f has a substantially mountain shape as a whole. The two surfaces of the convex portion 6f facing the support planes 2a to 2d (support planes 2b and 2d are not shown) of the support member 2 are the outer surfaces 6b to 6e (the outer surfaces 6c and 6e are not shown). The intersection of the two surfaces of the portion 6f is the top 3g. In addition, in order to suppress damage to the top part 3g and the support planes 2a to 2d with which the top part 3g contacts, it is desirable to round the intersection of the two surfaces of the convex part 6f. Such a bearing 6 can also exhibit an automatic alignment function while preventing rotation of the bearing 5 around the axis I.

  FIG. 7B shows a side sectional view of the bearing device 1 in which the bearing 7 according to the fourth modification is incorporated. The bearing 7 of this embodiment is extended along the X axis and faces four flat outer surfaces 7b to 7e (outer surface 7c) facing the support planes 2a to 2d (support planes 2b and 2d are not shown) of the support member 2. 7e is not shown), and a part of the outer surfaces 7b to 7e in the X-axis direction, specifically, a cross-sectional shape along the X-axis formed at the center of the outer surfaces 7b to 7e forms an outwardly convex arc shape The bearing 3 is different from the bearing 3 of the first aspect in having a convex portion 7f. The cross-sectional shape of the convex portion 7f is the same as the shape shown in FIG. 7B at any location on the Z-axis and the Y-axis, and the convex portion 7f has a substantially bowl shape as a whole. Yes. Such a bearing 7 can also exhibit an automatic alignment function while preventing rotation of the bearing 7 around the axis I.

  FIG. 7C shows a side sectional view of the bearing device 1 in which the bearing 8 according to the fifth modification is incorporated. The bearing 8 of this mode is basically the same configuration as the bearing 3 of the first mode, but the top of the convex portion 8f disposed on the outer surfaces 8b to 8e (outer surfaces 8c and 8e are not shown). 3g is different from the bearing 3 in that it is disposed at a position shifted to the left side (opening side of the hollow portion 3s into which the shaft portion 27a is inserted) by a distance c from the center F of the bearing 8 in the X-axis direction. ing. According to such a bearing 8, an automatic alignment function can be exhibited while preventing the bearing 8 around the shaft core I from being rotated, and the shaft portion 27 a is inserted into the hollow portion 3 s and the shaft portion 27 a is deformed. The thickness d of the left end portion of the bearing 8 that is relatively easily damaged can be increased, which is advantageous in terms of extending the life of the bearing 8.

  Next, in the bearing 3 according to the first aspect which is a preferred aspect, there is a possibility that it may occur due to the configuration relating to the circulation of the plating bath which is a lubricating medium interposed between the bearing 3 and the shaft portion 27a and the eccentricity of the shaft portion 27a. A configuration for preventing the bearing 3 from being damaged will be described. First, as for the former, the bearing 3 of this aspect is provided with a thrust receiver for receiving a right end surface of the shaft portion 27a of the support roll that moves in the X-axis direction during operation and restricts movement in the X-axis direction. The bearing end 3n is arranged at the right end. On the other hand, when the bearing end 3n is provided in this manner and the right end of the bearing 3 is closed, the plating bath as a lubricating medium is not smoothly supplied to the sliding surfaces of the bearing 3 and the shaft 27a, and foreign matter such as dross is not generated. There is a possibility of staying in the bearing 3. For this reason, the hot water pool portion 3L having a larger inner diameter than the hollow portion 3s and disposed in the region from the right end of the hollow portion 3s to the bearing end portion 3n and the bearing end portion 3n along the X-axis direction are penetrated. It is preferable to provide the bearing 3 with the through hole 3m formed as described above. With this configuration, even when the shaft portion 27a is inserted into the bearing 3, the plating bath circulates between the hot water pool portion 3L and the outside through the through hole 3m, and smoothly removes dross as a lubricating medium. Will function. Further, if the bearing end 3n is provided and the right end of the bearing 3 is closed, when the bearing device 1 is pulled up, a plating bath remains inside the bearing device 1, and the bearing 3 may be damaged in the process of cooling and solidifying the remaining plating bath. There is. For this reason, as shown in the figure, the through hole 3m is arranged such that its lower surface is located below the lower surface of the sliding surface 3a (the inner surface of the hollow portion 3s) in the Z-axis direction and flows into the bearing 3. It is desirable that the plated bath is discharged through the through hole 3m.

  Further, when the bearing end 3n is arranged at the right end of the bearing 3 as described above, the convex portion 3k whose top is in contact with the support surface 2m of the flat plate member 2i of the support member 2 that the bearing end 3n faces. Is preferably provided at the bearing end 3n. Thereby, the alignment of the bearing 3 with respect to the eccentricity of the shaft portion 27a is performed more smoothly.

  Next, the structure which prevents the damage of the bearing 3 which may arise with the eccentricity of the axial part 27a is demonstrated. As in the bearing 3 shown in FIG. 2, in the X-axis direction, the corner at the left end (one end) or the right end (the other end) of the sliding surface 3a, that is, the corner of the opening end of the hollow portion 3s, has an R surface. 3j is preferably provided. Thereby, it can prevent that the outer peripheral surface of the axial part 27a inclined by the deformation | transformation at the time of eccentricity is pressed on the corner | angular part of the opening end of 3 s of hollow parts, and damaging the corner | angular part. Also, in the bearing 3 that tilts in the direction of arrow C during automatic alignment, in order to prevent collision with the support planes 2a to 2d of the support member 2, the left end of the outer surface 3b to 3e of the bearing 3 in the X-axis direction or It is preferable to provide the R surfaces 3h and 3i at the corner at the right end. The R surfaces 3h to 3j may be C surfaces.

[Material composition]
The bearing 3 immersed in the plating bath and sliding with the shaft portion 27a is required to have corrosion resistance against the plating bath and wear resistance against sliding. Therefore, it is desirable that at least the sliding surface 3a portion of the bearing 3 is made of ceramics. Hereinafter, the suitable example is demonstrated about the case where the bearing 3 is comprised with ceramics. The same applies to the case where the bearings according to the first to fifth modifications and the bearings of the following second to fifth modes are made of ceramics.

  Ceramics include alumina, zirconia, silica and other oxide ceramics, zirconium boride, titanium boride, boride depending on the thermal shock resistance and corrosion resistance required by the operating conditions of the support roll and other operating conditions. Boron and other boride ceramics, silicon carbide / boron carbide and other carbide ceramics, or inorganic materials such as carbon may be used. The bearing 3 needs to be excellent in thermal shock resistance because it is rapidly heated / cooled when immersed in the plating bath and taken out. Therefore, as the ceramic constituting the bearing 3, silicon nitride / aluminum nitride and other nitride ceramics having high thermal conductivity are preferable and have high resistance to erosion and wear against molten metal as a plating bath. Silicon nitride ceramics excellent in high temperature strength are particularly preferable. Hereinafter, silicon nitride ceramics suitable for constituting the bearing 3 may be the same as those described in JP-A-2001-335368.

  Aluminum and oxygen present in the silicon nitride ceramic serve as a phonon scattering source and reduce the thermal conductivity. Silicon nitride ceramics are composed of silicon nitride particles and surrounding grain boundary phases, and aluminum and oxygen are contained in these phases. Since aluminum has an ionic radius close to that of silicon, it easily dissolves in silicon nitride particles. Due to the solid solution of aluminum, the thermal conductivity of the silicon nitride particles themselves is lowered, and the thermal conductivity of the silicon nitride ceramics is significantly lowered. Therefore, it is desirable to reduce the aluminum content in the silicon nitride ceramics as much as possible.

  Most of the oxygen in the oxide added as a sintering aid is present in the grain boundary phase. In order to achieve high thermal conductivity of silicon nitride ceramics, it is necessary to reduce the amount of grain boundary phase having lower thermal conductivity than silicon nitride particles. The lower limit of the addition amount of the sintering aid is such an amount that a sintered body having a relative density of 8.5% or more can be obtained. It is desirable to reduce the amount of oxygen in the grain boundary phase by making the addition amount of the sintering aid as small as possible within this range.

When silicon nitride powder with a small amount of oxygen is used as a raw material, the amount of oxygen in the grain boundary phase can be reduced, so the amount of grain boundary phase itself can be reduced, and high thermal conductivity of the sintered body can be achieved. It becomes difficult to sinter due to a decrease in the amount of SiO ₂ produced in the process. However, when MgO, which is superior in sinterability to other oxides, is used as a sintering aid, the amount of sintering aid added can be reduced and a dense sintered body can be obtained. As a result, the thermal conductivity of the sintered body is dramatically increased.

  Examples of sintering aids that can be added together with magnesium include Group 3 of the periodic table such as Y, La, Ce, Nd, Pm, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, and Lu (described later). Is mentioned. Among these, Y, La, Ce, Gd, Dy, and Yb are preferable in that the sintering temperature and pressure do not become too high.

  The thermal conductivity of silicon nitride ceramics constituting the bearing 3 at room temperature is 50 W / (m · K) or more, more preferably 60 W / (m · K) or more. Accordingly, the oxygen content in the silicon nitride ceramic is 5% by weight or less to obtain a thermal conductivity of 50 W / (m · K) or more, and a thermal conductivity of 60 W / (m · K) or more. Is 3% by weight or less. The oxygen content in the silicon nitride particles is 2.5% by weight or less for obtaining a thermal conductivity of 50 W / (m · K) or more, and a thermal conductivity of 60 W / (m · K) or more. Is 1.5% by weight or less. Furthermore, the aluminum content in the silicon nitride ceramic is 0.2% by weight or less for obtaining a thermal conductivity of 50 W / (m · K) or more, and a thermal conductivity of 60 W / (m · K) or more. Is 0.1% by weight or less.

  The total amount of magnesium MgO and Group 3 element oxides in the silicon nitride ceramic is preferably 0.6 to 7% by weight. When the total amount is less than 0.6% by weight, the relative density of the sintered body is less than 95%, which is insufficient. On the other hand, if it exceeds 7% by weight, the amount of the grain boundary phase having a low thermal conductivity becomes excessive, and the thermal conductivity of the sintered body becomes less than 50 W / (m · K). The MgO + Group 3 element oxide is more preferably 0.6 to 4% by weight.

  The weight ratio of MgO / Group 3 element oxide is preferably 1 to 70, more preferably 1 to 10, and most preferably 1 to 5. If the MgO / Group 3 element oxide is less than 1, the ratio of the rare earth oxide in the grain boundary phase is too high, and it becomes difficult to sinter and a dense sintered body cannot be obtained. On the other hand, if the MgO / Group 3 element oxide exceeds 70, the diffusion of Mg during sintering cannot be suppressed, and color unevenness occurs on the surface of the sintered body. When the MgO / Group 3 element oxide is in the range of 1 to 70, the thermal conductivity is significantly increased by sintering at 1650 to 1850 ° C. When the sintered body is heat-treated at 1800 to 2000 ° C., the thermal conductivity is further increased. The increase in thermal conductivity by heat treatment is due to the growth of silicon nitride particles and volatilization of MgO having a high vapor pressure.

  The total amount of aluminum, magnesium, and Group 3 elements in the periodic table in the silicon nitride particles is preferably 1.0% by weight or less.

  Of the β-type silicon nitride particles in the silicon nitride sintered body, when the proportion of β-type silicon nitride particles having a minor axis diameter of 5 μm or more exceeds 10% by volume, the thermal conductivity of the sintered body is improved. Since the coarse particles introduced into the film act as a starting point of fracture, the fracture strength is remarkably lowered, and a bending strength of 700 Mpa or more cannot be obtained. Therefore, the ratio of β-type silicon nitride particles having a minor axis diameter of 5 μm or more in the β-type silicon nitride particles in the silicon nitride sintered body is preferably 10% by volume or less. Similarly, the β-type silicon nitride particles preferably have an aspect ratio of 15 or less in order to prevent the coarse particles introduced into the structure from acting as a starting point of fracture.

The silicon nitride ceramic forming the bearing 3 needs to have a sufficient resistance to sudden temperature changes. The resistance to sudden temperature changes is the following formula (1):
R = αc (1−ν) / Eα (1)
(However, αc: Four-point bending strength (MPa) at normal temperature, ν: Poisson's ratio at normal temperature, E: Young's modulus (MPa) at normal temperature, α: Average thermal expansion coefficient from normal temperature to 800 ° C)
The coefficient R represented by the coefficient represented by is preferably 600 or more, and more preferably 700 or more. If the coefficient R is less than 600, the bearing 3 may be broken. The coefficient R is the four-point bending strength αc (MPa) at room temperature measured for the specimen cut out from the bearing 3, the Poisson's ratio ν at room temperature, the Young's modulus E (MPa) at room temperature, and the average heat from room temperature to 800 ° C. Obtained from the expansion coefficient α.

[Second Embodiment]
A bearing according to a second aspect of the present invention will be described with reference to FIG. FIG. 8 is a front view of the bearing device 9 in which the bearing 18 of the second aspect is incorporated. The bearing 18 of this aspect is that the outer surface where the convex part which has an automatic centering function is formed is only the two outer surfaces 3b and 3c with respect to the bearing 3 incorporated in the bearing device 1 of the first aspect. Is different. Hereinafter, the support member 10 and the bearing 18 that constitute the bearing device 9 of this aspect will be described in detail.

[Support member]
As shown in FIG. 8, the support member 10 of the second aspect has two support planes orthogonal to each other, specifically, an upper support plane 10a and a left support plane 10b. The support planes 10a and 10b are inner surfaces (one surface) of the flat plate members 10c and 10d that are combined so as to be substantially orthogonal to each other. The support member 10 is fixed to the end portion 25a of the frame 25 extended into the plating bath in such a posture that the support plane 10a faces downward and the support plane 10b faces right.

[bearing]
The bearing 18 of the second aspect is basically the same configuration as the bearing 3 of the first aspect. That is, the outer peripheral surface of the shaft portion 27a of the support roll having a substantially cylindrical shape slides, the sliding surface 3a extending in the X-axis direction, and the X-axis direction that is the same direction as the sliding surface 3a extends. It has the outer surface 3b * 3c in which the convex-shaped part 3f of the form similar to the bearing 3 of the said 1st aspect was formed while being extended. However, in the bearing 18, the outer surfaces on which the convex portions 3 f are formed are only the upper and left outer surfaces 3 b and 3 c, and the outer surfaces 3 b and 3 c are formed on the two support planes 10 a and 10 b of the support member 10. They are facing each other. Convex portions may also be formed on the surface of the bearing 18 facing the outer surfaces 3b and 3c, that is, the lower surface and the right surface, but the outer surface having an automatic alignment function is supported by the support planes 3b and 3c. Only the outer surfaces 3b and 3c facing each other.

  The bearing 18 having the above-described configuration is formed on the support member 10 such that the top 3g of each convex portion 3f is in contact with the support planes 10a and 10b with the outer surface 3b facing the support plane 10a and the outer surface 3c facing the support plane 10b. Installed. The bearing 18 attached to the support member 10 is preferably fixed by a flat plate-like fixing member 25c provided at the right end of an arm 25b extending rightward from the lower end of the front end portion 25a of the frame 25. The lower right portion is pressed and fixed to the support member 10. An elastic body 25d using a compression spring or the like is interposed between the arm 25b and the fixing member 25c, and the bearing 18 is fixed in an expandable / contractable state. In addition, since the force shown by the arrow D in the figure acts on the support roll immersed in the plating bath due to the tension applied to the steel plate, the fixing member 25c and the elastic body 25d for fixing the bearing 18 are essential. However, it is preferable to provide the bearing 18 in order to stably fix the bearing 18 to the support member 10.

  According to the bearing device 9 incorporating the bearing 18 having such a configuration, the outer peripheral surface of the shaft portion 27a of the support roll that rotates counterclockwise as shown by an arrow E in FIG. 8 is in contact with the sliding surface 3a of the bearing 18. Slide while. As shown in FIG. 8, since the load indicated by the arrow D acts on the support roll, the bearing 18 supports the shaft portion 27a at the upper left portion of the sliding surface 3a, and the outer surface 3b. The top portions 3g of the convex portions 3f provided on the two surfaces 3c are in contact with the support planes 10a and 10b of the support member 2 facing each other.

  When the shaft portion 27a is deformed by heating with a high-temperature plating bath or a load applied from the steel sheet and the shaft core is eccentric, the bearing 18 has a Y-axis and a Z-axis according to the eccentric amount of the shaft portion 27a. A rotational moment around the axis acts. Here, the top portions 3 g of the convex portions 3 f provided on the outer surfaces 3 b and 3 c of the bearing 18 are in contact with the support planes 10 a and 10 b of the support member 2. Thus, in the direction around the Y axis, the bearing 18 is eccentric with respect to the support plane 10a with the top 3g of the convex portion 3f provided on the outer surface 3b as a fulcrum because of the rotational moment around the Y axis. Tilt according to the amount. Further, in the direction around the Z axis, the bearing 18 has an eccentric amount with respect to the support plane 10b with the top 3g of the convex portion 3f provided on the outer surface 3c as a fulcrum because of the rotational moment around the Z axis. Tilt according to. The displacement of the bearing 18 accompanying the tilting is allowed by the elastic body 25d that can be expanded and contracted. Thus, out of the rotational moment acting on the bearing 18 due to the eccentricity of the shaft portion 27a, the component around the Y axis is provided on the outer surface 3b, and the component around the Z axis is provided on the outer surface 3c. The bearing 18 can be automatically aligned according to the amount of eccentricity of the shaft portion 27a by receiving it separately at the convex portion 3f and tilting each of them. Further, since the top 3g of the convex portion 3f formed on each of the outer surface 3b and the outer surface 3c is in contact with the support planes 10a and 10b orthogonal to each other, the outer peripheral surface of the shaft portion 27a and the sliding surface 3a of the bearing 18 are provided. The bearing 18 does not rotate around the axis I due to the frictional resistance when sliding. Further, in the bearing device 10 of this aspect, since the surfaces other than the support planes 10a and 10b facing the outer surfaces 3b and 3c of the bearing 18 are open, the plating bath is interposed between them when the bearing device 10 is pulled up. It is difficult to remain, and it is possible to further prevent damage to the bearing 18 than the bearing device 1 of the first aspect.

[Third Embodiment]
A bearing according to a third aspect of the present invention will be described with reference to FIG. FIG. 9A is a side sectional view of the bearing device 10 in which the bearing 12 of the third aspect is incorporated. The bearing 12 according to this aspect is basically configured to correspond to the eccentricity of the shaft portion 37a and exhibit an automatic alignment function and prevent the bearing 12 from being rotated in the same manner as the bearing 3 according to the first aspect. However, the bearing end that is a thrust receiver that restricts the movement of the support roll in the X-axis direction is not at the right end, and the hollow portion 3s into which the shaft portion 37a is inserted extends from the left end (one end) to the right end (the other end). ) And the right end is also open. Further, the support member 11 that supports the bearing 12 is also configured such that there is no flat member disposed at the right end, and the plating bath flows more smoothly inside the support member 11. The bearing 12 is also fixed to the right end surface by a fixing member 2n (not shown) arranged on the support member 11 (see FIG. 1), similarly to the left end surface, and movement in the X-axis direction is restricted.

  Here, in the bearing device 10 of this aspect in which the bearing 12 without the bearing end portion is incorporated, the movement of the support roll in the X-axis direction is restricted by the following configuration. That is, the shaft portion 37a has large diameter portions 37b and 37c formed on the right and left sides in the X-axis direction, and a small diameter portion 37d formed between the left and right large diameter portions 37b and 37c. The small-diameter portion 37d is formed with restricting surfaces 37e and 37f extending in the Z-axis direction. The small-diameter portion 37d is formed between the left and right regulating surfaces 37e and 37f so that both end surfaces of the hollow portion 3s of the bearing 12 can be inserted. In the bearing device 10, the shaft portion 37a configured as described above is passed through the hollow portion 3s having a larger diameter than the large-diameter portion 37e, and the hollow portion is interposed between the left and right regulating surfaces 37e and 37f. It is arranged so that 3s is located. With the above configuration, when the support roll moves in the X-axis direction, the left and right regulating surfaces 37e and 37f that are in contact with both end surfaces of the hollow portion 3s of the bearing 12 are regulated.

[Fourth Embodiment]
The bearing of the 4th aspect concerning this invention is demonstrated referring FIG.9 (b). FIG. 9B is a side sectional view of the bearing device 13 in which the bearing 14 of the fourth aspect is incorporated. The bearing 14 of this aspect is basically configured to perform the same function as the bearing 3 of the first aspect, but includes a main body part 14c formed with a sliding surface 3a on which the shaft part 27a slides. This is different in that it is constituted by a combination of the two members of the holding portion 14a which holds the main body portion 14c and has the four outer surfaces 3b to 3e provided with the convex portion 3f. In the case of this bearing 14, there is an advantage that the main body portion 14c and the holding portion 14a can be made of different materials. The holding part 14a which forms the convex part 3f with a metal such as stainless steel that can be easily processed may be formed on the part 14c. When the holding portion 14c is made of metal, it is desirable to form a film such as ceramics or cermet on the surface in order to improve the corrosion resistance against the plating bath. Hereinafter, the main body portion 14c and the holding portion 14a of the bearing 14 will be described in detail. In addition, since the structure of a supporting member is the same as the supporting member 2 of a 1st aspect, description is abbreviate | omitted.

[Main unit]
As described above, the main body portion 14c having the sliding surface 3a on which the outer peripheral surface of the shaft portion 27a slides has a substantially fan-shaped cross section in the ZY plane perpendicular to the shaft core I. It is a sliding surface 3a. In addition, the shape of the main-body part 14c is not limited above, A semi-annular shape may be sufficient and an annular shape may be sufficient. That is, the main body portion 14c only needs to have the sliding surface 3a.

[Holding part]
The external shape of the holding portion 14a that holds the main body portion 14c is the same as that of the bearing 3 of the first aspect, and extends in the X-axis direction and extends to the four support planes 2a to 2d of the support member 2 that are orthogonal to each other. Each has four outer surfaces 3b to 3e facing each other, and the outer surfaces 3b to 3e are respectively provided with convex portions 3f whose top portions 3g are in contact with the support planes 2a to 2d. A hollow portion 14d through which the shaft portion 27a can be inserted is formed along the X axis at the center of the holding portion 14a, and corresponds to the direction of arrow D where the support roll receives a load. An insertion recess 14b having a substantially fan-shaped cross-section in which the main body 14c is inserted is provided at the corner. Here, the main body portion 14c inserted into the insertion recess 14b is fixed so that the sliding surface 3a, which is the inner surface, protrudes from the inner surface of the hollow portion 14d, and the shaft portion is attached to the protruding sliding surface 3a. 27a rotates smoothly while contacting.

  According to the bearing device 13 in which the bearing 14 having such a configuration is incorporated, the outer peripheral surface of the shaft portion 27a of the support roll slides while being in contact with the sliding surface 3a of the main body portion 14c. Since the load indicated by the arrow D acts on the support roll, the top 3g of the convex portion 3f provided on the two outer surfaces 3b and 3c of the holding portion 14a faces the support plane of the support member 2 facing these. It will be in the state which touches 2a * 2b.

  When the shaft portion 27a is eccentric, a rotational moment about the Y axis and the Z axis acts on the bearing 14 in accordance with the eccentric amount. Since the top portions 3g of the convex portions 3f provided on the outer surfaces 3b and 3c of the holding portion 14a are in contact with the support planes 2a and 2b of the support member 2, the bearing 14 is rotated about the Y axis and the Z axis. In each direction, the outer surface 3b tilts with respect to the support plane 2a according to the amount of eccentricity, and the bearing 14 according to the amount of eccentricity of the shaft portion 27a, with the top 3g of the convex portion 3f as a fulcrum for each rotational moment. The automatic alignment is performed. Moreover, since the top 3g of the convex portion 3f formed on each of the outer surface 3b and the outer surface 3c is in contact with the support planes 2a and 2b, the bearing 14 does not rotate around the axis I.

[Fifth Embodiment]
The bearing of the 5th aspect concerning this invention is demonstrated referring FIG. FIG. 10 is a side sectional view of the bearing device 15 in which the bearing 17 and the support member 16 of the fifth aspect are incorporated. The bearing 17 of this aspect is basically configured to perform the same function as the bearing 3 of the first aspect, but differs in that the convex portion is provided on the support member instead of the bearing. ing. Hereinafter, the structure will be specifically described in the order of the bearing 17 and the support member 16.

[bearing]
The bearing 17 of this aspect has the sliding surface 3a extended in the X-axis direction on which the shaft portion 27a slides, similarly to the bearing 3 of the first aspect, but the four outer surfaces 17b to 17e (17c. 17e is a plane orthogonal to each other (hereinafter referred to as a support plane for convenience in this embodiment for the sake of understanding). That is, the support plane of the support member 2 of the first aspect is provided in the bearing 17 in place of the support member in this aspect.

[Support member]
Similar to the support member 2 of the first aspect, the support member 16 of this aspect is combined with a substantially U-shape of five flat plate members 2e to 2i (the flat plate members 2f and 2h are not shown), and the bearing 17 Of the four flat members 2e to 2h extending in the X-axis direction (hereinafter referred to as inner surfaces for the sake of understanding) 16a to 16d (16b). (16d is not shown) faces the support planes 17b to 17e of the bearing 17, and the inner surfaces 16a to 16d are provided with convex portions 16r where the top faces 16s are in contact with the support planes 17b to 17e facing each other. It has been. That is, the surface on which the convex portion of the bearing 3 of the first aspect is provided is provided on the support member 16 in place of the bearing in this aspect.

  In this way, the support plane and the surface on which the convex portion is provided are interchanged between the bearing and the support member, so that the rotation around the shaft core I is prevented in the same manner as the bearings of the first to fourth aspects. However, the bearing 17 can exhibit an automatic alignment function. In addition, since the outer surfaces 17b to 17e are flat, the bearing 17 of this aspect can be easily formed by machining or the like, and is particularly advantageous when the bearing 17 is made of difficult-to-work ceramics.

1 (9, 13, 15) Bearing device 2 (10, 11, 16) Holding member 2a (2b-2d, 17b-17e) Plane (support plane)
2e (2f to 2i) Flat plate member 2j (2k to 2L) Through hole 2q Storage chamber 3 (4 to 8, 12, 14, 17, 18) Bearing 3a Sliding surface 3b (3c to 3e, 16a to 16d) Surface (Outer surface, inner surface)
3f (3k, 16r) Convex part 3g (16s) Top part 3L Hot water pool part 3m Through hole 3o (3p-3r) Connection surface 3s Hollow part 20 Molten metal plating apparatus 21 Molten metal plating bath 27 Support roll 28 Sink roll W Steel sheet

Claims (13)

A bearing for a molten metal plating bath that rotatably supports a shaft portion of a rotating body immersed in a molten metal plating bath and supported by a support member having four adjacent planes ,
Has a sliding surface which the outer peripheral surface of the shaft portion slides, a fourth surface facing each to the four planes of the support member with extends in the same direction in which the sliding surface extends, The four metal surfaces are formed with a convex portion in contact with a flat surface facing each other and a top portion. The outer edge shape of the convex portion in the direction in which the sliding surface extends is an arc shape,
2. The bearing for a molten metal plating bath according to claim 1, wherein the support member is formed with a through-hole that communicates with the top of the convex portion whose outer edge shape is an arc shape.   The bearing for a molten metal plating bath according to claim 1, wherein the flat surface is formed on the bearing instead of the support member, and the surface is formed on the support member instead of the bearing.   The said support member has a support surface set | placed on the one end side of the plane of the said support member, Furthermore, the said bearing for molten metal plating baths has the convex-shaped part which a top part contacts the said support surface. The bearing for molten metal plating baths in any one. The melting according to any one of claims 1 to 4, wherein a gap is provided between a top of the convex portion formed on the surface of the bearing and a plane of the support member to which the surface of the bearing faces. Bearing for metal plating bath.   The bearing for a molten metal plating bath according to any one of claims 1 to 5, wherein an outer edge shape of the convex portion in a direction in which the sliding surface extends is an arc shape.   The bearing for a molten metal plating bath according to claim 6, wherein the convex portion whose outer edge shape is an arc shape is formed from one end to the other end of the surface of the bearing in a direction in which the sliding surface extends.   The convex portion having an arcuate outer edge shape is disposed at a position where a top portion of the convex portion is deviated to one end side from a center of a surface of the bearing in a direction in which the sliding surface extends. A bearing for a molten metal plating bath according to any one of the above.   The bearing for molten metal plating baths according to any one of claims 6 to 8, wherein a connecting surface for connecting each of the bearing surfaces is interposed between adjacent surfaces.   The bearing for a molten metal plating bath according to claim 9, wherein a shape of the connection surface is an arc shape bulging outward in a cross-sectional view along a direction orthogonal to a direction in which the sliding surface extends. In the direction in which the sliding surface extends, at least one corner of one end and the other end face of the bearing, the molten metal according to any one of claims 1 to 10 R plane or C plane is formed Bearing for plating bath. The molten metal according to any one of claims 1 to 11 , wherein an R surface or a C surface is formed at at least one corner of one end and the other end of the sliding surface in a direction in which the sliding surface extends. Bearing for plating bath. The bearing for a molten metal plating bath according to any one of claims 1 to 12 , wherein the sliding surface of the bearing is made of ceramics.

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