JP5446116B2 - Slide bearing mechanism - Google Patents

Description

  The present invention relates to a sliding bearing mechanism, and more particularly to reduction of vibration of a bearing of a rotary sinker used by being immersed in a molten metal bath at the time of manufacturing a galvanized steel wire.

  In order to give corrosion resistance to the steel wire used in a corrosive environment, the surface is plated with, for example, molten zinc. In order to plate the steel wire, it is necessary to immerse the steel wire in the molten metal bath 13 on the production line as shown in FIG. This mechanism is generally called a sinker. The sinker mechanism is roughly divided into a fixed sinker system (Fig. 1 (a) that is made of a hard material such as fused silica and that passes through a steel wire by rubbing under a member having a passage groove. )), And a rotating sinker system (FIG. 1 (b)) that has a shaft and a bearing, and in which the cylindrical surface rotates in the bath and guides the steel wire without rubbing with the steel wire.

  The fixed sinker has a simple structure and no moving parts, so the guide of the steel wire is stable and there is little blurring of the wire. However, the steel wire and the sinker member rub against each other. When the material passing resistance on the feeding side is large and as a result, the surface pressure becomes high, a phenomenon may occur in which the surface of the wire is wrinkled or the sinker guide surface is scraped off.

  Regarding the relationship between the shaft and the bearing of the rotary sinker, a fixed journal is provided in the fixed bearing, and this journal is connected to the body that guides the steel wire, and the rotation rotates around the fixed shaft. A rotary bearing system (FIG. 2) in which a bearing is provided and the rotary bearing is coupled to a body portion for guiding a steel wire can be selected. Hereinafter, the rotary bearing system will be described.

  The advantage of the rotary sinker is that there is no friction between the steel wire and the sinker member, so that the surface can be passed without any wrinkles on the surface. When the speed is increased, the rotation of the rotary bearing occurs around the fixed shaft, and the vibration is transmitted to the line, so that the line is vibrated and the surface quality becomes unstable.

  The reason why the rotary bearing is likely to run around the fixed shaft is that the rotary sinker has a sliding bearing mechanism between the rotary bearing and the fixed shaft, as compared to a bearing used at room temperature and in the atmosphere. This is because an extremely large clearance is provided.

  In the present invention, since the slide bearing mechanism is immersed in the molten metal bath, the molten metal enters between the rotary bearing and the fixed shaft during operation. If the distance between the rotary bearing and the fixed shaft is narrow as in a normal slide bearing mechanism, when the rotary sinker is lifted from the molten metal during maintenance, the molten metal that has entered between the rotary bearing and the fixed shaft will spread over the entire circumference due to surface tension. Due to the difference between the remaining solid metal solidified by the temperature drop and the shrinkage rate of the rotary bearing and the fixed shaft, the subsequent cooling causes stress on the rotary bearing or the fixed shaft member, resulting in damage. The reason why it is necessary to provide a large clearance between the rotary bearing and the fixed shaft in the plain bearing mechanism immersed in the molten metal is that it is easy to remove from the large space between the rotary bearing and the fixed shaft when lifted from the molten metal. This is because it is necessary to let the molten metal flow out naturally.

  Therefore, in order to produce a high quality plated wire without wrinkles on the surface of the iron wire, a rotating sinker that does not rub against the wire is essential. It was very difficult to operate stably without causing any problems.

  As an existing technology related to reduction of shaft runout of a slide bearing mechanism, as disclosed in Patent Document 1, a preload is applied to a plurality of plate-like slide bearings by a leaf spring or an elastic body in a scanner motor bearing structure. In addition, a technique for reducing the inclination of the rotating body has been proposed.

  However, in the case of the above mechanism, the preload is applied by the leaf spring or the elastic body. In the case of the mechanism in the molten metal to be proposed in the present invention, the rigidity of the leaf spring or the elastic body is gradually lost due to the high temperature. It is difficult to apply because it is broken or the material is denatured.

  Further, since it is necessary to press the gap between at least three of the fixed sliding member and the member for biasing the preload without any gap, the solidification shrinkage rate of the molten metal remaining between the journal and the fixed bearing and the member as described above are maintained. Due to the difference in the shrinkage rate, excessive stress is generated in the member and it is damaged, so that it cannot be applied under the situation assumed by the present invention.

  Further, as disclosed in Patent Document 2, a technique has been proposed in which the shape of the bearing hole is substantially triangular and the number of contacts with the shaft is three, thereby greatly reducing the generation of heat.

  However, in this case as well, in the case of the mechanism used in the molten metal to be proposed in the present invention, since it is restrained from three sides without a gap, the solidification shrinkage rate of the solidified metal and the thermal shrinkage rate of the member at the time of maintenance are determined. Due to the difference, stress is generated and the member is damaged, so that it cannot be applied.

Japanese Patent Laid-Open No. 5-180217 Japanese Utility Model Publication No. 7-1721

  The present invention has been made in view of such a situation, and occurs due to the large clearance between the rotary bearing and the fixed shaft, taking advantage of the fact that the iron wire, which is a feature of the rotary sinker, is not easily wrinkled. An object of the present invention is to provide a plain bearing mechanism that reduces vibration.

The present invention has been made to solve the above problems, and the gist of the present invention is as follows.
(1) At the time of manufacturing a hot-dip galvanized steel wire, which is composed of a rotary bearing 1 having a circular cross section perpendicular to the shaft and having a space 7 inside the inner periphery and a fixed shaft 2 penetrating the space 7 of the rotary bearing 1 A sliding bearing mechanism of a rotary sinker used by being immersed in a molten metal bath, wherein a cross-sectional shape perpendicular to the axis of the fixed shaft 2 is a polygon, an ellipse, or a combination thereof, The contact portion 5 between the fixed shaft 2 and the inner periphery 8 of the rotary bearing 1 has two shapes in a cross section perpendicular to the shaft, and at least 50% of the inner peripheral surface of the rotary bearing 1 is opposed to the opposing fixed shaft. A sliding bearing mechanism characterized in that the interval is 2 mm to 20 mm.
(2) The sliding bearing mechanism according to (1), wherein an angle formed by a tangent to the inner periphery 8 of the rotary bearing at the two contact portions 5 is 30 to 150 ° .
(3 ) The sliding bearing mechanism according to (1) or ( 2) , wherein each of the fixed shaft 2 and the rotary bearing 1 has a thermal shock resistance of ΔT: 500 ° C. to 1200 ° C.
( 4 ) At least one of the fixed shaft 2 and the rotary bearing 1 has a Vickers hardness of 9.8 × 10 ³ MPa or more, and both have a Vickers hardness of 34.3 × 10. ^The plain bearing mechanism according to any one of (1) to ( 3 ), which is ³ MPa or less.

  According to the sliding bearing mechanism according to the present invention, for example, in the process where it is necessary to pass the steel wire through the molten metal bath while being crushed on the production line of the molten metal plating wire, the steel wire which is a feature of the rotary sinker is used. Utilizing the features that are difficult to get wrinkled, eliminating the vibration that occurs between the rotary bearing and the fixed shaft, can stably produce hot-plated wire with extremely stable surface properties, and trouble during maintenance Therefore, the industrial contribution is very remarkable.

  The structure of the plain bearing mechanism of the present invention will be described. The plain bearing mechanism of the present invention is a combination of a fixed shaft and a rotary bearing as illustrated in FIG. In the present invention, the space 7 of the rotary bearing 1 refers to a space inside the inner periphery of the rotary bearing 1 and through which the fixed shaft 2 passes. The inner circumference 8 of the rotary bearing 1 refers to an inner circumference that forms a boundary between the rotary bearing 1 and the space 7.

  The space 7 provided in the rotary bearing of the slide bearing mechanism has a circular shape in which the cross section perpendicular to the rotation axis is concentric, but the diameter does not necessarily have to be the same depending on the position of the cross section. A combination is also acceptable.

  The fixed shaft 2 is immersed and fixed in the molten metal bath 13. The rotary bearing 1 has a space 7 through which the fixed shaft 2 passes. In the present invention, the shape of the fixed shaft 1 is such that when it is used as a sliding bearing mechanism in a molten metal bath, the contact portion between the inner periphery 8 of the rotary bearing 1 and the fixed shaft 2 is shown in FIG. The cross section is perpendicular to the axis and has two locations (5a, 5b).

  The basic operation of the present invention will be described below. In a sliding bearing mechanism of a rotating sinker for guiding a steel wire in a molten metal assumed to be used by the present invention, as shown in FIG. Ten line tensions 4a and 4b are applied. A characteristic is that the direction in which the rotary bearing 1 is pressed against the fixed shaft 2 by the resultant force 4c of the linear tension is substantially determined at the time of operation. The installation direction of the fixed shaft is adjusted so that the direction of the resultant force 4c of the line tension on the incoming line side and the outgoing line side substantially coincides with the vicinity of the middle point of the two contact points (5a, 5b) with the rotary bearing 1.

  In the slide bearing in the molten metal bath having a single contact point between the rotary bearing and the fixed shaft shown in FIG. 4, the force applied to the rotary bearing 1 is usually as shown in FIG. 5. The drag 3 received from the contact point 2 and the resultant force 4c of the tension 4a, 4b received from the steel wire are balanced and stationary. However, if the magnitudes of the vectors of the tensions 4a and 4b change during operation, the direction of the resultant force 4c changes, and it is the contact 5 in FIG. 1 must move on the fixed shaft 2, and the rotary bearing 1 is shaken.

  When the rolling bearing shakes, the pass line of the wire passing through fluctuates, and the surface of the iron wire vibrates, causing turbulence and sagging in the unsolidified molten metal covering it. This causes a quality problem that is likely to be rough.

  On the other hand, when the structure is such that the outer surface of the fixed shaft is in contact with the inner periphery 8 of the rotary bearing at two locations (5a, 5b) as in the present invention, the rotary bearing 1 is usually as shown in FIG. The drags 3a and 3b are received from two locations (5a and 5b) of the fixed shaft 2, and the tensions 4a and 4b are received from the steel wire and are in a balanced state.

  Even if the magnitudes of the line tensions 4a and 4b change during operation, as shown in FIG. 8, the drags 3a and 3b received by the rotary bearing 1 from the two locations (5a and 5b) of the fixed shaft 2 are linear tensions. As long as it changes according to the fluctuation and does not exceed the adjustment range of the line tensions 4a and 4b, that is, as long as either 4a or 4b does not become 0 (zero), the rotary bearing 1 does not change its position. Since the balance of force can be maintained, the rotation of the rotary bearing 1 can be continued without causing the rotation of the rotary bearing 1.

  Next, the positional relationship between the contact points of the fixed shaft in the present invention will be described. FIG. 9 shows the definition of the angle θ formed by the two tangent lines (6a, 6b) at the contact locations (5a, 5b). When the angle θ formed by the tangent lines (6a, 6b) at the points (5a, 5b) where the rotary bearing 1 and the fixed shaft 2 are in contact exceeds 170 °, the direction of the vector of the force that the rotary bearing receives from two locations of the fixed shaft Therefore, the magnitude of the line tension fluctuation easily exceeds the range of adjustment due to the fluctuation of the drag, and one of 4a and 4b becomes 0, and two of the contact points (5a and 5b) There is a possibility that any one of them loses contact with the fixed shaft, and the position of the shaft is deviated. Therefore, in the present invention, it is preferable that the angle θ formed by the tangent line at the point where the rotary bearing and the fixed shaft are in contact with each other is 170 ° or less. In order to further stabilize the shaft position, the angle θ is more preferably 150 ° or less.

  Further, when the angle θ formed between the tangents (6a, 6b) drawn at the points (5a, 5b) where the rotary bearing 1 and the fixed shaft 2 are in contact is smaller than 30 °, the rotary bearing 1 is fixed by frictional force. The force that is pushed in the direction of the shaft 2 is increased, and in some cases, the possibility of occurrence of a phenomenon in which the rotational speed is rather non-uniform due to galling or the like is increased. For this reason, in the present invention, it is preferable that the angle θ formed by the tangent line at the point where the rotary bearing 1 and the fixed shaft 2 contact each other is 30 ° or more.

  Next, the cross-sectional shape of the fixed shaft 2 will be described. The cross-sectional shape of the fixed shaft 2 in the present invention may be any shape as long as it can be in contact with the inner periphery 8 of the rotary bearing 1 at two locations as described above. A shape as shown in FIG. By making the cross-sectional shape to be all or a part of an arc, a polygon, an ellipse, or a combination thereof, it is possible to reliably make two contact points. As shown in FIG. 3G, two protruding members 14 may be embedded.

  Next, the interval between the rotary bearing 1 and the fixed shaft 2 will be described. It is preferable that at least 50% of the inner peripheral surface of the rotary bearing 1 has a distance of 2 mm or more from the opposed fixed shaft. This is because when the sliding bearing mechanism is removed from the molten metal bath during maintenance, the molten metal that has entered between the rotating bearing and the fixed shaft during operation does not remain between the rotating bearing and the fixed shaft due to surface tension. The interval is set to 2 mm or more so as to be easily discharged from the slide bearing mechanism.

  However, it is desirable that at least 50% of the inner peripheral surface of the rotary bearing 1 has a distance of 20 mm or less from the opposed fixed shaft. This is an interval of about 20 mm, the molten metal discharge effect at the time of maintenance is saturated, and if the interval exceeds 20 mm, the rotary bearing becomes large, and a useless space for installing the slide bearing mechanism is necessary. This is because there is a possibility of becoming.

  Next, the thermal shock resistance of the rotary bearing and the fixed shaft will be described. Thermal shock resistance is defined as the maximum temperature difference that does not cause cracking when a certain material is ripened and dropped into ice water with a temperature difference ΔT and rapidly cooled. Both the fixed shaft and the rotary bearing in the present invention preferably have a thermal shock resistance of ΔT ≧ 500 ° C.

  The reason for this is that when the thermal shock resistance ΔT of the rotary bearing and the fixed shaft is less than 500 ° C., the rotary bearing and This is because internal residual stress is generated in the member of the fixed shaft itself and may be damaged.

  In addition, even if the material has a thermal shock resistance ΔT exceeding 1200 ° C., the effect of suppressing cracks is saturated when used in a molten metal bath used for ordinary plating. An impact property ΔT of 1200 ° C. or less is sufficient.

As a material of the rotary bearing and the fixed shaft, a Co—Cr based metal spray material is applied to the surface of a silicon nitride (Si ₃ N ₄ ) based fine ceramics group including sialon (SiAlON) or a stainless steel material such as SUS316. By adopting a coating of about 2 mm, the thermal shock resistance ΔT can be in the range of 500 to 1200 ° C.

Further, it is preferable that at least one of the fixed shaft and the rotary bearing has a Vickers hardness of 9.8 × 10 ³ MPa or more. When both the fixed shaft and the rotary bearing are less than 9.8 × 10 ³ MPa, the friction between the rotary bearing and the fixed shaft tends to cause adhesion or peeling, and the unevenness of the wear surface increases. Since wear may progress in a relatively short time, it may be difficult to continue stable operation for a long period of time. For this reason, it is preferable that either the rotary bearing or the fixed shaft has a Vickers hardness of 9.8 × 10 ³ MPa or more.

Further, it is preferable that both the fixed shaft and the rotary bearing have a Vickers hardness of 34.3 × 10 ³ MPa or less. The reason for this is that if either the fixed shaft or the rotary bearing exceeds 34.3 × 10 ³ MPa, the fracture toughness tends to be reduced, so that there is a high possibility that it will be damaged by being hit during handling such as maintenance. Because.

In order to set the Vickers hardness to 9.8 × 10 ³ MPa or more, about 1 to 2 mm is coated with a Si ₃ N ₄ -based or silicon carbide (SiC) -based fine ceramics group or a metal-based thermal spray material such as Co—Cr. However, in the case of SiC, the hardness is too high, and the fracture toughness and thermal shock resistance are reduced. Therefore, the Si ₃ N ₄ ceramics or Co-Cr metal spray material By selecting, the Vickers hardness can be in the range of 9.8 to 34.3 × 10 ³ MPa.

  Examples are shown below. In addition, this Example is demonstrated concretely along an example, The content of the claim of this invention is not limited.

  As the plating wire, a hot rolled material of JIS SWRM6-5.5 mmφ was used, and an iron wire cold-drawn to 4.0 mmφ was used. After drawing out the stretch material, it was annealed in a fluidized bed at 750 ° C for about 45 seconds, pickled with hydrochloric acid at 15% and 60 ° C, washed with water, passed through a flux of ammonium chloride aqueous solution, dried with blower, and then melted with pure zinc at 450 ° C. Soaked in a tank. The line speed was 30 mm / min, the shallow dipping time in the molten zinc bath was 10 seconds, and the bath surface of the portion where the plated wire was pulled up was sealed by nitrogen ventilation.

  As the structure of the rotary sinker, as shown in FIG. 2, a body portion 9 for guiding an iron wire, a rotary bearing 1 having a concentric space 7 integrated therein, and a fixed shaft 2 received through the space 7. It was carried out with an apparatus consisting of

The material of the rotary bearing was made of general-purpose sialon having thermal shock resistance ΔT = 600 ° C. and Vickers hardness of 13.6 × 10 ³ MPa. The fixed shaft was made of SUS316, and the surface was subjected to thermal spraying of Co—Cr and cut to a thickness of 2 mm and finished. However, Comparative Example No. 1 in Table 1 was used. For No. 3, the material of the rotary bearing was SUS316 without coating. In addition, No. of the present invention example. The fixed shaft of No. 7 is Al ₂ O ₃ series fine ceramics, No. 7 No. 8 fixed shaft and rotary bearing are both SUS316, No. Each of the fixed shafts 9 is made of SiC fine ceramics.

  The rotary bearing and the body portion for guiding the iron wire are concentric and integral, and the diameter of the space of the rotary bearing is 80 mm, the body diameter is 180 mm, and the groove for guiding the iron wire has a depth of 10 mm.

  As the cross-sectional shape of the fixed shaft, in the example of the present invention, each shape, hexagon, and octagon shown in FIGS. In the case of a quadrangle, it is an approximate square with a side of 70 mm, and the corner portion of the square is R13 mm. In the comparative example, the shape of the fixed shaft 2 is a circle shown in FIG. The length of the cylindrical side surface portion of the fixed shaft in contact with the inner peripheral surface of the rotary bearing is 300 mm. A projection having a square cross section was formed at the end, and this was fitted into the same-shaped hole of a 19 mm-thick SUS304 support to suppress co-rotation with the rotary bearing. As shown in FIG. 3, when used as a sliding bearing mechanism in a molten metal bath, the contact location between the inner periphery 8 of the rotary bearing 1 and the fixed shaft 2 is two in a cross section perpendicular to the shaft (5a, 5b). ), The direction of the shape of the fixed shaft 2 was adjusted.

  Table 1 shows the production conditions and evaluation results during the production of the plated wire of the example.

  First, the evaluation method will be described.

  The evaluation of “vibration” in Table 1 was judged by shaking the wire during operation, visually checking the surface of the plated wire, and shaking directly on the base of the rotary sinker. The case where the vibration of the line corresponding to the rotation period of the sinker and the continuous vibration as perceived by the palm from the pedestal occurred, and the unsolidified molten zinc on the surface of the plated wire dripped or disturbed was marked as x. Moreover, although generation | occurrence | production of the vibration was felt, it was set as (triangle | delta), and the case where generation | occurrence | production of a vibration was not felt was set as (circle) when the plating wire surface is beautiful.

The evaluation of "wear state" is that after producing a plated wire of about 100t under the above conditions, the rotating sinker is lifted from the molten zinc bath, the slide bearing mechanism is disassembled, and the rubbing surfaces of the rotating bearing and the fixed shaft are visually observed. I went there. The case where no circumferential streak could be confirmed on the scratched surface was rated as “◯”. Although it was possible to clearly confirm the circumferential streak on any of the rubbing surfaces, the case where no vibration was generated in the plated wire during the operation and there was no problem in the surface quality was indicated as Δ. A case in which circumferential streaks could be clearly confirmed on the scraped surface, and the plating wire vibrated during operation, causing a problem in the appearance of the surface, was evaluated as x.

  The evaluation of “breakage resistance” was performed by rapidly immersing the rotating sinker after completion of maintenance in a molten zinc bath, rapidly lifting it after operation, and visually observing cracks, chipping, and the like. ○, when cracks, chipping, etc. are not observed, cracks, chipping, etc. can be observed visually, but if the plating wire does not vibrate during operation and there is no problem in surface quality, Δ, cracks, chipping, etc. The case where the plating wire vibrates during operation and a problem occurs in the surface appearance is marked as x.

  The evaluation of the “shaft position stability” was made by deliberately pushing the straightening roller before entering the molten zinc bath on the sinker side during operation and returning it immediately to change the line tension. It was judged visually whether or not this occurred. At this time, when the plated wire is not blurred, ○, when the plated wire is temporarily blurred, but only when the surface quality is disturbed and does not lead to the overall quality degradation, the plated wire is blurred and the surface appearance The case where a problem occurs in the case is marked with x.

“Rotational stability” was evaluated by deliberately pushing in the straightening roller before entering the molten zinc bath on the sinker side during operation, increasing the line tension constantly, and increasing the line tension. Judgment was made based on whether the speed changed. At this time, ○ when there is no change in the line speed, △ when the speed of the plated wire fluctuates because the fixed shaft is firmly fitted into the rotary bearing, but there is no problem in surface quality, and the line speed is When it fluctuated and a problem arises in the plating wire surface appearance, it was set as x.

The evaluation of “maintenance of molten metal during maintenance” was judged by the remaining state of molten metal in the gap between the fixed shaft and the rotary bearing when the rotating sinker was lifted from the molten metal bath during maintenance. At this time, when the molten metal does not remain, ◯, when molten zinc remains, but can be scraped with a metal brush, etc., when there is no problem in surface quality, △, cannot be scraped with a metal brush, etc. When the zinc remained, it was set as x.

  In Comparative Examples 1 to 3, since the shape of the fixed shaft 2 is circular and the number of contact points between the fixed shaft and the rotary bearing is one for each sliding bearing mechanism, the position of the rotary bearing varies periodically. This is an example in which vibration is constantly generated in the plated wire during the operation and the vibration evaluation becomes x, which deteriorates the surface quality.

  In Example 4 of the present invention, since the distance between the fixed shaft and the rotary bearing is narrow, when it is lifted from the molten zinc at the time of maintenance, it remains unless the molten zinc is forcibly removed by any method, and the subsequent heat shrinkage difference This is an example in which the member may be deformed or broken, and the evaluation of molten metal residualness during maintenance was Δ.

  In Example 5 of the present invention, since the angle θ formed by the tangent line between the fixed shaft and the rotary bearing is as small as 25 °, galling is likely to occur between the fixed shaft and the rotary bearing, and the rotation may become unstable. In this example, the rotational stability evaluation was Δ.

  In Example 6 of the present invention, since the angle θ formed by the tangent lines drawn from the two contact points between the fixed shaft and the rotary bearing is as large as 175 °, the difference in the vector direction of the drag force that the rotary bearing receives from the two points of the fixed shaft In this example, the range for absorbing fluctuations when the tension of the iron wire fluctuates is narrow, the shaft may be shaken, and the evaluation of the shaft position stability is Δ.

  In Example 7 of the present invention, since the thermal shock resistance of the fixed shaft is as low as 300 ° C., when immersed in a molten zinc bath or when it is lifted from the molten zinc, stress is easily generated inside the member, and there is a possibility of breakage. There is an example in which the evaluation of breakage resistance was Δ.

In Invention Example 8, since both the fixed shaft and the rotary bearing have a low Vickers hardness of 3.5 × 10 ³ MPa, uneven wear on the sliding surface within a short time from the start of use. This is an example in which a stable operation for a long period of time becomes difficult, and the evaluation of wear status and rotational stability is Δ.

In Example 9 of the present invention, the Vickers hardness of the fixed shaft is too high at 45 × 10 ³ MPa, so the fracture toughness and thermal shock resistance are low. This is an example in which the evaluation of breakage resistance is Δ because it is easily damaged by impact.

  Examples 10 to 16 of the present invention satisfy all the conditions that are preferable in the present invention, so that the hot-dip galvanized wire is not wrinkled and vibrations during operation are extremely small, and stable. This is an example in which a plated wire of a certain quality can be manufactured for a long time and maintenance can be performed without any problem.

It is sectional drawing of the hot dipping bath of a steel wire, (a) represents a fixed sinker and (b) represents a rotary sinker. It is an example of the plain bearing mechanism of this invention. It is a specific example of the cross-sectional shape of the fixed shaft of the slide bearing mechanism of the present invention, (a) is a quadrangle, (b) is a triangle, (c) is a quadrangle combined with an inwardly convex curve, and (d) is a channel type. (E) is an ellipse, (f) is a quadrangle combined with an outwardly convex curve, and (g) is an embedding of two protruding members. This is the shape of a conventional plain bearing mechanism. It is a figure which shows the stress state at the time of the steady state of the conventional slide bearing mechanism. It is a figure which shows the state at the time of the stress fluctuation | variation of the conventional slide bearing mechanism. It is a figure which shows the stress state at the time of the steady state of the slide bearing mechanism of this invention. It is a figure which shows the state at the time of the stress fluctuation | variation of the sliding bearing mechanism of this invention. It is a figure which shows the angle which the tangent forms in the contact part of the sliding bearing mechanism of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating bearing 2 Fixed shaft 3, 3a, 3b Drag 4a, 4b Tension 4c Combined force 5a, 5b Contact of rotary bearing and fixed shaft 6a, 6b Contact tangent 7 Space 8 Inner circumference 9 Body 10 Steel wire 11 Rotating sinker 12 Fixed sinker 13 Molten metal bath 14 Protruding member θ Angle formed by two tangents

Claims (4)

It is immersed in a molten metal bath when manufacturing a hot-dip galvanized steel wire, which is composed of a rotary bearing having a circular cross section perpendicular to the axis and having a space inside the inner periphery and a fixed shaft that penetrates the space of the rotary bearing. The slide bearing mechanism of a rotary sinker used in the above-mentioned configuration has a cross-sectional shape perpendicular to the axis of the fixed shaft, which is a polygon, an ellipse, or a combination thereof, and the fixed shaft and the rotary bearing The contact portion with the inner periphery of the rotary bearing has two cross-sections perpendicular to the shaft, and at least 50% of the inner peripheral surface of the rotary bearing has a distance of 2 mm to 20 mm between the opposing fixed shaft. A plain bearing mechanism characterized by   The plain bearing mechanism according to claim 1, wherein an angle formed by a tangent to the inner periphery of the rotary bearing at the two contact portions is 30 to 150 °. The sliding bearing mechanism according to claim 1 or 2 , wherein both the fixed shaft and the rotary bearing have a thermal shock resistance of ΔT: 500 ° C to 1200 ° C. At least one of the fixed shaft and the rotary bearing has a Vickers hardness of 9.8 × 10 ³ MPa or more, and both have a Vickers hardness of 34.3 × 10 ³ MPa or less. The sliding bearing mechanism according to any one of claims 1 to 3 .

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